Can u guys tell me which are the Best Surrond Sound Systems? 5.1 or 7.1? Help. [Text View]

sdurani

11-06-08, 02:23 AM

well ive heard of Bose,Sony,Panasonic,Logitech and others.Actually, I had asked what speakers you'd heard, not brands you'd heard of. No matter. Speaker choice comes down to personal taste. I could tell you which speakers I like the sound of, but you and I could have very different tastes. Since you (not me) will be the one living with these speakers, you should buy something that sounds good to you.

Take a couple of CDs that you are very familiar with, go to a local A/V store and listen to some speakers that are within your budget. Buy what you like, and you like what you've bought. Nothing more complicated than that. so everbody here owns a 5.1 setup. i thought 7.1 was the new way to go. so i should just go with 5.1....You asked about the "majority" of people; I don't know how you turned that into "everybody" here. There are plenty of posters here at AVS that have 7.1 set-ups. But it doesn't matter what others have. You should set up whatever your room can accomodate. If your couch is against the back wall, then I would do a 5.1 set-up (no space behind you for the rear speakers). If your couch is at least a few feet away from the back wall, then I would definitely do a 7.1 configuration. i heard that blu-ray movies support something called DTS-HD which is true HD surround sound, how do i get true HD sound.Blu-ray has the capability to deliver soundtracks that are bit-for-bit copies of what the sound mixer created in the studio. This is done using uncompressed PCM digital audio or one of two lossless compression codecs: Dolby TrueHD and DTS-HD Master Audio (both are the equivalent of zipping a file to save space).

Your PS3 can internally decode up to 7.1 channels of TrueHD and DTS-MA, transmitting the lossless signal as uncompressed PCM to a HDMI-equipped receiver. Player-wise, you've already got it all (including Blu-ray's interactive feature: BD Live). Most modern receivers, even budget models, are 7.1-channel. So your options are wide open as far as speaker set-up goes. Look for a receiver with HDMI inputs and some sort of room correction system.

First figure out what you want to spend. That will help you decide what receiver models and speakers to consider.

Sanjay

jarrod1937

11-06-08, 04:57 PM

"Far from it" for you. We're getting into personal preference here, which is why I ended my last post with "And for me, that qualifies as 'better'. YMMV."

The typical home theatre doesn't allow all listeners to be seated in the sweet spot. Imaging stability may not be the "all encompassing component of good audio", but it certainly is important when all but one listener will be off-axis.

Sanjay
True, though being honest i didn't know what YMMV until just now ;) and i somehow missed the "for me" section. Now its more obvious to me you were stating an opinion, earlier i misunderstood you as stating that information as a fact, sorry for the misunderstanding.
I, personally, tend to take a more objective approach to sound quality. To me the less the enclosure resonates, the flatter and wider the frequency response, the lower the distortion from the drivers...etc the better the sound quality. Things such as a speaker being too "bright", or having "muddied" lows can easily be measured and seen. Hence my original statement, by better, i meant better all around audio, audio that is clearer and offers to play all that is to be played. Cheaper speakers have non-linear frequency responses, more distortion, may have "holes" in and may lack the lower end of the frequency response. Things of this nature can not be made up for. Based on this, it would give a better end result to buy fewer higher quality speakers, than buy lots of lower quality speakers.
I suppose this is still an opinion and so is up for judgment, but again, my definition of "better" is about as objective as you can get.

sdurani

11-08-08, 03:56 PM

Cheaper speakers have non-linear frequency responses, more distortion, may have "holes" in and may lack the lower end of the frequency response.Oh please, you're not going to suffer such dramatic differences in speaker quality just because you're buying a couple more surround speakers with the same budget. It's not like you saved up for 2 speakers and now have to spread that same cash over 7 speakers and a sub.

Once you've settled on a brand of speakers that you like, the incremental cost difference between 5.1 and 7.1 packages will at best allow you to go with the next model up the line. If you look at typical lines of speakers, you'll notice that the next model up usually only buys some low frequency extension. Not very useful when you're already using a subwoofer. I suppose this is still an opinion and so is up for judgment, but again, my definition of "better" is about as objective as you can get.No. Your personal preferences about speaker configuraions aren't more objective than someone elses preferences. Keep in mind that buying fewer speakers may allow you to buy better quality models, but using fewer speakers also brings with it limitations. One better quality speaker cannot image a stereophonic soundstage the way two lesser quality speakers can. Likewise, one pair of surrounds, no matter how good they are, can't be in two locations simultaneously: at your sides and behind you.

Sanjay

HDgeneration

11-08-08, 05:48 PM

Raymond Leggs

11-08-08, 05:54 PM

sdurani

11-08-08, 07:55 PM

A truly good system will sound good no matter where you are in the room/ soundfield. :rolleyes:But a truly excellent system will sound good even when you are outside the room.

Sanjay

HDgeneration

11-08-08, 08:11 PM

jarrod1937

11-08-08, 09:57 PM

A truly good system will sound good no matter where you are in the room/ soundfield. :rolleyes:
Agreed

But a truly excellent system will sound good even when you are outside the room.

Sanjay
Strange statement coming from you, as if you're outside the room you're obviously outside the prime imaging area. How audio sounds is more so based on all of my points i previously stated. If you're worried so much about imaging, then you really need to do some room treatments. Proper room treatments will allow for a wider imaging stage due to less con/decon-structive interference. Even more important is to realize that you'll actually get more interference the more speakers you have. So if you're truly worried about imaging you would not want a 7.1 as that would in fact shrink the prime imaging area if the room were untreated (more interference zones).
As for the money you'd save going from the 7.1 to 5.1, well, if you're building the system yourself that can equal a total of $400 saved (assuming you're buying mid quality and up speakers). Which is $400 extra that could go to the sub, which could make a nice difference. However, if you apply that money to the speakers instead, you could get that low frequency extension that you spoke of... which is more important than you seem to realize. The perk of fuller range speakers is that you can set the subwoofer crossover lower, allowing you to better adjust your bass management and better integrate the sub into your sound systems audio. Or the extra money could perhaps be better spent on some room treatments, which could make a very large difference to both sound quality and imaging, depending on the room of course.

"No. Your personal preferences about speaker configuraions aren't more objective than someone elses preferences."

You say that, but mine are based off of the study of physics, physiology, measurements, and past experience with audio involving myself and others. Your opinion seems to be based on that imaging is of prime importance and nothing else matters nearly as much, which is incorrect, even if its just an opinion does not exempt it from being judged. Imaging is important, yes, but once you get that, there are many more factors that judge the quality of the audio. It is not opinion that a flatter, wider frequency range sounds better than a comb filtered/crazily varied, lacking frequency range.

jarrod1937

11-08-08, 10:06 PM

What would be a better choice getting a HTIB or just buy everything separately i might be willing to spend less than 1500. i think i will go with a 5.1 because i have a couch against the wall and i wouldnt be able to put another speaker behind me. Do u need a receiver or im i just good with the Speakers? Also what if i get a 7.1 receiver would it work with a 5.1 surround sound system
With your budget you could build a respectable system by buying everything separately. You'll want to buy a receiver to power the speakers.
Personally i'd try to find a few places locally to tryout some speakers that are within, or barely outside your price range and get a list of some you like. Then search online for them, sometimes you can save a few hundred by going online, even with the price of shipping added. Try to buy speakers with the same max wattage and ohm rating, from there then you can pickout your receiver to match your speaker choices.

sdurani

11-09-08, 12:10 AM

Strange statement coming from you, as if you're outside the room you're obviously outside the prime imaging area.A bit of sarcasm in response to a pointless tautology. He might as well have said good speakers sound good. So if you're truly worried about imaging you would not want a 7.1 as that would in fact shrink the prime imaging area if the room were untreated (more interference zones).Other way 'round. The more speakers you use, the larger the sweet spot.

For example: with a 7.1 set-up, sounds intended to come from behind you will always come from that direction, no matter where you're sitting. No magic involved, just a pair of speakers placed behind the listening area (makes it difficult for those sounds to come from any other direction).

With a 5.1 layout, you have to sit almost exactly between the two surround speakers in order to get a phantom rear image. And because it is a phantom image, if you move, the image moves with you. For listeners seated outside the sweet spot, sounds intened to come from behind them will instead image towards their side (whichever surround speaker they're closer to).

The same thing happens up front when comparing 2 speakers to 3. With 2 speakers, only the listener seated in the sweet spot will hear vocals/dialogue in the centre of the soundstage. With 3 speakers, it doesn't matter where you sit, sounds intended to come from the centre of the soundstage will always appear at that location.

Since the soundfield becomes more stable with more speakers, the size of the sweet spot does too. Quite the opposite of what you're claiming.

BTW, why are you assuming an untreated room? The perk of fuller range speakers is that you can set the subwoofer crossover lower, allowing you to better adjust your bass management and better integrate the sub into your sound systems audio.Setting the crossover lower also means that more low frequencies end up stuck where your speakers are. In typical rooms, the locations for best soundstage and imaging are different from the locations that give best bass reproduction. So even with speakers that are fuller range, better to filter off the low frequencies and send them to a dedicated sub, which can: a) usually reproduce bass better than speakers, and b) be placed where ever bass reproduction is optimal in the room. Or the extra money could perhaps be better spent on some room treatments, which could make a very large difference to both sound quality and imaging, depending on the room of course.Room treatments? So now we're no longer talking about fewer speakers = better speakers. In that case, why not forego the centre and surrounds altogether and have to room professionally measured and treated, which could make an even larger difference in sound quality? It is not opinion that a flatter, wider frequency range sounds better than a comb filtered/crazily varied, lacking frequency range.Again, you're being overly dramatic about what cost savings of 2 fewer surrounds will buy. Lets take the figure you used for a pair of surrounds: $400. Spread out over 5.1 speakers, an additional $400 is not going to make the difference between "flatter, wider frequency range" speakers and "comb filtered/crazily varied, lacking frequency range" speakers.

Sanjay

sdurani

11-09-08, 12:25 AM

Do u need a receiver or im i just good with the Speakers?You can't plug speakers into your PS3, so you'll need a receiver. Look for a model with HDMI inputs and decent room correction (e.g., Audyssey). Shouldn't cost more than roughly 1/3rd of your $1500 budget. Also what if i get a 7.1 receiver would it work with a 5.1 surround sound systemYes. Modern receivers can also scale the number of channels in the soundtrack to the number of speakers in your set-up. So 2-channel material can be upmixed for 5.1 speakers and 7.1-channel material can be downmixed for 5.1 speakers. During intitial set up, just tell your receiver how many speakers you have and it will do the rest automatically.

Sanjay

jarrod1937

11-09-08, 12:36 AM

A bit of sarcasm in response to a pointless tautology. He might as well have said good speakers sound good. Other way 'round. The more speakers you use, the larger the sweet spot.

For example: with a 7.1 set-up, sounds intended to come from behind you will always come from that direction, no matter where you're sitting. No magic involved, just a pair of speakers placed behind the listening area (makes it difficult for those sounds to come from any other direction).

With a 5.1 layout, you have to sit almost exactly between the two surround speakers in order to get a phantom rear image. And because it is a phantom image, if you move, the image moves with you. For listeners seated outside the sweet spot, sounds intened to come from behind them will instead image towards their side (whichever surround speaker they're closer to).

The same thing happens up front when comparing 2 speakers to 3. With 2 speakers, only the listener seated in the sweet spot will hear vocals/dialogue in the centre of the soundstage. With 3 speakers, it doesn't matter where you sit, sounds intended to come from the centre of the soundstage will always appear at that location.

Since the soundfield becomes more stable with more speakers, the size of the sweet spot does too. Quite the opposite of what you're claiming.

BTW, why are you assuming an untreated room? Setting the crossover lower also means that more low frequencies end up stuck where your speakers are. In typical rooms, the locations for best soundstage and imaging are different from the locations that give best bass reproduction. So even with speakers that are fuller range, better to filter off the low frequencies and send them to a dedicated sub, which can: a) usually reproduce bass better than speakers, and b) be placed where ever bass reproduction is optimal in the room. Room treatments? So now we're no longer talking about fewer speakers = better speakers. In that case, why not forego the centre and surrounds altogether and have to room professionally measured and treated, which could make an even larger difference in sound quality? Again, you're being overly dramatic about what cost savings of 2 fewer surrounds will buy. Lets take the figure you used for a pair of surrounds: $400. Spread out over 5.1 speakers, an additional $400 is not going to make the difference between "flatter, wider frequency range" speakers and "comb filtered/crazily varied, lacking frequency range" speakers.

Sanjay
I'm not even going to attempt to respond to each of your points and insist you study some physics. There is a reason most speakers use the vertical driver alignment as opposed to the horizontal alignment, the same problem occurs with speakers horizontally aligned and gets worse with the more speakers added.
The only points i will respond to directly are:
"BTW, why are you assuming an untreated room?"
Do you understand what audio treatment is? If you do, you'll know 99% of all rooms really need to be professionally treated with things like bass traps and so on in order to not go crazy with comb filtering due to first/second reflection points that cause excessive wave interference based on the point of incident and relative wavelengths of each frequency. Since this guy is so new to audio, i doubt he has gone the extra step or will go the extra step of proper room treatments to prevent this... And yes, room treatments probably are the most important aspect to good audio. Your system can cost 1 million and still suck because of bad room acoustics. Hence why i suggested that perhaps with the $400 saved, it may be possible to do some room treatment diy style.

"In typical rooms, the locations for best soundstage and imaging are different from the locations that give best bass reproduction."
Quite true. But you're missing a couple of points. If all of your speakers are full range, then all of the frequencies they produce will in fact be produced in 5 different locations, assuming a 2 channel source matrixed to 5.1. This will have the affect of multiplying the output from each speaker allowing a high relative dB output for those lower frequencies, which can be nice. Assuming the input is a 5.1 source, then the lower frequencies will be produced by each speaker, which is fine depending on how low you want to go as some bass frequencies are still directional to some extent. However, you also have the benefit of overlapping the bass frequencies produced by the speakers and the sub by having an overlap in the subs crossover range, this can have the affect of giving you a dB boost in those frequencies, which may help smooth out any impedence dips you may have around those areas. Now, i will give it to you, that if you have a truly excellent sub, it may be best to route all lower frequencies to it, but this will vary per situation as it depends highly on the room acoustics (again assuming its untreated) on whether it would be better or not.

tbrunet

11-09-08, 09:04 AM

During the original (mastering) production process..all the discrete surround reference monitors are full range and his/her mix determines the coded freq spectrum for each surround channel including the (.1) LFE

It's now common in the 21 century for HT owners to have relatively high quality surrounds that have no problem with the "large" setting and LFE crossover point somewhere around ~80 Hz.

Kal Rubinson

11-09-08, 11:27 AM

I'm not even going to attempt to respond to each of your points and insist you study some physics. There is a reason most speakers use the vertical driver alignment as opposed to the horizontal alignment, the same problem occurs with speakers horizontally aligned and gets worse with the more speakers added.Only if they are reproducing the same signal and are displaced by more than 1/2 the wavelength.

jarrod1937

11-09-08, 11:39 AM

Only if they are reproducing the same signal and are displaced by more than 1/2 the wavelength.
Correct, but quite frequently you will get that interference as:
1.) If playing a 2 channel source, usually the same audio is reproduced by each speaker.
2.) Quite frequently you do get overlaps in frequencies produced by each speaker, even in discreet channels, such as panning.

That and if we're assuming an untreated room, the effect will be amplified. I've actually measured nulls that have been produced in one seating position during a panning test from one speaker to another. It would happen just before it fully transitioned to the other speaker and disappeared afterward. But of course it is impossible to predict which speakers will cause what problems with what frequencies, as it all varies per persons setup.

Kal Rubinson

11-09-08, 11:43 AM

Correct, but quite frequently you will get that interference as:
1.) If playing a 2 channel source, usually the same audio is reproduced by each speaker.Yes but, aside from a centered mono source which is better reproduced from a discrete channel, there should be timing/phase differences.
2.) Quite frequently you do get overlaps in frequencies produced by each speaker, even in discreet channels, such as panning. Yup. Unfortunate. Fortunately, for me, the music I listen to has a minimum of that. It is also a transient effect and less noticeable.

That and if we're assuming an untreated room, the effect will be amplified. No argument there. All things are worse in an untreated acoustic space.

sdurani

11-09-08, 01:12 PM

Hence why i suggested that perhaps with the $400 saved, it may be possible to do some room treatment diy style.No, what you originally suggested was: "...assuming your budget is fixed, go with 5.1. Fewer better quality speakers are always better than more lesser quality speakers."

My point is that it's not "always" better, and I've given examples of the advantages that more speakers have over fewer speakers. If those advantages aren't high on your list of priorities, then so be it. But that doesn't make what's important to you somehow more objective than what others consider important.

As for treating the room: it's is a valid concern, but totally orthogonal to a discussion about number/quality of speakers. If playing a 2 channel source, usually the same audio is reproduced by each speaker.Whether playing a 2-channel or multi-channel source, 7.1 surround processing typically has unique sounds reproduced from each speaker. Quite frequently you do get overlaps in frequencies produced by each speaker, even in discreet channels, such as panning.Unavoidable, whether you're playing back using 5.1 or 7.1 speakers. However, more channels/speakers does lessen the problem.

For example: using two speakers up front means that anything intended for the centre of the soundstage (vocals, instrument solos) is reproduced as dual-mono, phantom-imaged, comb-filtering sound. With three speakers up front, those same sounds are now reproduced by single speaker, minimizing the overlaps and comb-filtering you're talking about.

Sanjay

jarrod1937

11-09-08, 02:05 PM

No, what you originally suggested was: "...assuming your budget is fixed, go with 5.1. Fewer better quality speakers are always better than more lesser quality speakers."

My point is that it's not "always" better, and I've given examples of the advantages that more speakers have over fewer speakers. If those advantages aren't high on your list of priorities, then so be it. But that doesn't make what's important to you somehow more objective than what others consider important.

As for treating the room: it's is a valid concern, but totally orthogonal to a discussion about number/quality of speakers. Whether playing a 2-channel or multi-channel source, 7.1 surround processing typically has unique sounds reproduced from each speaker. Unavoidable, whether you're playing back using 5.1 or 7.1 speakers. However, more channels/speakers does lessen the problem.

For example: using two speakers up front means that anything intended for the centre of the soundstage (vocals, instrument solos) is reproduced as dual-mono, phantom-imaged, comb-filtering sound. With three speakers up front, those same sounds are now reproduced by single speaker, minimizing the overlaps and comb-filtering you're talking about.

Sanjay
"but totally orthogonal to a discussion about number/quality of speakers. "
Incorrect, read previous posts to see why.

"7.1 surround processing typically has unique sounds reproduced from each speaker."
Incorrect, given a 2 channel source, even 7.1 processing will repeat audio between multiple speakers. It is not magically able to produce 100% discrete channeling for each and every speaker.

"But that doesn't make what's important to you somehow more objective than what others consider important."
What i suggested originally and still stand by it is that you can save money by going 5.1 rather than 7.1 and then better spend those savings on other areas or better speakers to improve the audio. This is not really a matter of opinion but a fact. As an example, again, say you save $400 by dropping two speakers, that can be spent on a better sub ($400 can make a larger difference there), or it can be better spent on room treatments. This all in all can make a better quality sound system. However, i do agree that if you had the space and all the money needed for the entire project to get things like treatments, then i do agree 7.1 would win overall. But since the original poster has a set budget, that is where my disagreement stems, as money can be more frugally spent to give a higher quality sound system with that set budget. If money were no concern i would choose 7.1 in a heart beat.

"Unavoidable, whether you're playing back using 5.1 or 7.1 speakers"
True and never said it was avoidable with one or the other. However it is worsened by having more speakers, which does give 5.1 an edge over 7.1.

Raymond Leggs

11-09-08, 05:03 PM

. Whether playing a 2-channel or multi-channel source, 7.1 surround processing typically has unique sounds reproduced from each speaker. .

Sanjay

No it don't if you select All Channel Stereo on the amp when playing a 2 channel source. And just because a DVD has 7.1 suround options does not mean it is true 7.1. Some DVD's just put the same info that was going into the side speakers into the rear speakers and the processor in the amp just plays it back the way it was told to. :rolleyes:

HDgeneration

11-09-08, 05:49 PM

well i went the different websites and i found these receivers that i think are good....what do think????
http://www.circuitcity.com/ssm/Onkyo-TX-SR806-7-1-THX-Dolby-TrueHD-and-DTS-HD-Home-Theater-Receiver-TXSR806/sem/rpsm/oid/215620/catOid/-12949/rpem/ccd/productDetail.do

http://www.circuitcity.com/ssm/Onkyo-TX-SR606-7-1-Dolby-TrueHD-and-DTS-HD-Home-Theater-Receiver-TXSR606/sem/rpsm/oid/208513/catOid/-12949/rpem/ccd/productDetail.do

http://www.circuitcity.com/ssm/Denon-AVR-889-7-1-Dolby-TrueHD-and-DTS-HD-Home-Theater-Receiver-AVR889/sem/rpsm/oid/215624/catOid/-12949/rpem/ccd/productDetail.do

Tulpa

11-09-08, 07:40 PM

I wouldn't get the Onkyo 806 unless there are features on it that you need that the 606 doesn't have.

The Onkyo 606 and Denon are both nice. The Denon has a tad more power and some more features, but I'm not sure it justifies almost $400 more, unless you find it a hell of a lot cheaper somewhere else.

In terms of receivers, get one from a good brand (Denon and Onkyo are fine, as are Marantz and Harmon-Kardon) that has just the features you want/need, and splurge on speakers (or room treatments if you're going that far.) No need to get an expensive receiver with bells and whistles you'll never use just because the price tag is higher.

Raymond Leggs

11-09-08, 08:03 PM

Harmon Kardon and Marantz are better than Onkyo.

HDgeneration

11-09-08, 09:51 PM

Raymond Leggs

11-09-08, 10:14 PM

okay so i the 606 is okay. im still looking for some speakers can someone help? thanks guys.

I think Polk audio carries a nice bang for the buck system, of if you prefer some good slam for the price if you listen to agressive music I would recommend the sony SSF 55000 towers, and / or the SSB-3000 bookshelf speakers and the matching center and possibly the matching or even better an entry level infinity sub.

Polk audio also has some good bang for the buck towers and bookshelves and subs, some people complain that the polk subs are too boomy or not enough low bass/ cabinet rattles but I didnt hear any rattles on the model they had at best buy.

sdurani

11-10-08, 12:15 AM

No it don't if you select All Channel Stereo on the amp when playing a 2 channel source.But if you select the Mono Mode, all the sound will come out of one speaker. And just because a DVD has 7.1 suround options does not mean it is true 7.1.No DVDs have 7.1 audio, so I don't know what you're trying to get at.

Sanjay

sdurani

11-10-08, 12:18 AM

Incorrect, given a 2 channel source, even 7.1 processing will repeat audio between multiple speakers. It is not magically able to produce 100% discrete channeling for each and every speaker.The Boston Audio Society sells a test/demo CD that includes a 2-channel track where the test tone circles the room when used with 7-channel surround processing (either PLIIx or LOGIC7). This would be impossible if, as you say, "the same audio is reproduced by each speaker". The only reason it works is because each speaker is getting independently steered content. No one has to take my word for this, as anyone can order the CD and prove it to themselves.

BTW, no one is claiming that surround processing yields "discrete" channels, just distinct ones. What i suggested originally and still stand by it is that you can save money by going 5.1 rather than 7.1 and then better spend those savings on other areas or better speakers to improve the audio.What you suggested originally was: "...assuming your budget is fixed, go with 5.1. Fewer better quality speakers are always better than more lesser quality speakers."

No mention of "other areas", just speakers. If you want to change your story, that's fine. But let's not pretend that you were originally suggesting the saved money be spent on anything other than speakers. However it is worsened by having more speakers, which does give 5.1 an edge over 7.1.I gave you a straightforward example of how additional speakers reduce the amount of overlapped content being reproduced, thereby reducing the very comb-filtering that you were talking about. Do you have an example of how using fewer speakers can do the same?

Sanjay

tbrunet

11-10-08, 07:51 AM

The Boston Audio Society sells a test/demo CD that includes a 2-channel track where the test tone circles the room when used with 7-channel surround processing In the "real world" sound sources and instruments are NOT just simply panned by signal amplitude alone;). Please do some research on virtual surround panning (Studer).. where implementing your beloved Dolby PLIIx would result in "distorting" the original complex sound field.

Thanks in advance!

sdurani

11-10-08, 10:12 AM

In the "real world" sound sources and instruments are NOT just simply panned by signal amplitude alone;).What does that have to do with the fact that 7.1 processing doesn't reproduce "the same audio" from each speaker, as jarrod1937 claimed?

BTW, the BAS demo uses amplitude and phase to steer the signals, not just "amplitude alone". The only reason I cited it as an example is because it refutes the notion that "If playing a 2 channel source, the same audio is reproduced by each speaker".

Sanjay

tbrunet

11-10-08, 11:07 AM

BTW, the BAS demo uses amplitude and phase to steer the signals, not just "amplitude alone". Still to simplistic. Real world virtual panning technics are way more complex than just amplitude or "phase".

sdurani

11-10-08, 11:16 AM

Real world virtual panning technics are way more complex than just amplitude or "phase".Again, how does this have any bearing on the fact that 7-channel processing doesn't reproduce "the same audio" from each speaker?

Sanjay

tbrunet

11-10-08, 11:22 AM

Just trying to avoid distorting the original sound-field with PLIIx like artifacts.

sdurani

11-10-08, 11:49 AM

Just trying to avoid distorting the original sound-field with PLIIx like artifacts.How does your personal feelings towards PLIIx refute the fact that 7-channel processing doesn't send "the same audio" to each speaker?

Sanjay

tbrunet

11-10-08, 11:52 AM

No personal "feelings" at all, rather PLIIx steering artifacts.

sdurani

11-10-08, 11:56 AM

No personal "feelings" at all, rather PLIIx steering artifacts.How is that related to the fact that 7-channel processing doesn't send "the same audio" to each speaker? Why aren't you answering the question?

Sanjay

jarrod1937

11-10-08, 11:57 AM

The Boston Audio Society sells a test/demo CD that includes a 2-channel track where the test tone circles the room when used with 7-channel surround processing (either PLIIx or LOGIC7). This would be impossible if, as you say, "the same audio is reproduced by each speaker". The only reason it works is because each speaker is getting independently steered content. No one has to take my word for this, as anyone can order the CD and prove it to themselves.

As already stated test signals are a bit different in these matters than complex audio. And when i stated same audio, i also very distintly mentioned that as being a frequency overlap.

BTW, no one is claiming that surround processing yields "discrete" channels, just distinct ones. What you suggested originally was: "...assuming your budget is fixed, go with 5.1. Fewer better quality speakers are always better than more lesser quality speakers."

Discrete by its very definition means "unique"/separate/on its own. Saying there is not freuqncy or audio content overlap on any speaker is saying that the audio is 100% discrete.

No mention of "other areas", just speakers. If you want to change your story, that's fine. But let's not pretend that you were originally suggesting the saved money be spent on anything other than speakers. I gave you a straightforward example of how additional speakers reduce the amount of overlapped content being reproduced, thereby reducing the very comb-filtering that you were talking about. Do you have an example of how using fewer speakers can do the same?

Sanjay
Taking my original quote:
"...assuming your budget is fixed, go with 5.1. Fewer better quality speakers are always better than more lesser quality speakers."
Again, assuming the budget is fixed, fewer speakers that have better quality audio are better... I was merely attacking your original arguement that more equals better, which it does not, while asserting that a fuller range speaker with a flatter frequency response is better. You can argue otherwise, but you're still incorrect. Some things, in a subjective topic, are simply not subjective.
Along with that i must say, "But let's not pretend that you were originally suggesting the saved money be spent on anything other than speakers."
Is a bit childish, conversations evolve, so do debates... no one is pretending anything. Along with the line of discussion, room treatments popped up as a good suggestion to the conversation and to a possibility for the original poster, so i figured i would bring it up.
So far you seem to be argueing for the sake of arguring, i say give it up and attempt to actually help the original poster in his quest for good audio.

jarrod1937

11-10-08, 12:04 PM

How is that related to the fact that 7-channel processing doesn't send "the same audio" to each speaker? Why aren't you answering the question?

Sanjay
There is some audio overlap on two or more speakers in a true 7.1 processed sound stream. This is especially true given a 2 channel source. Now, the same audio will be produced by each speaker if you apply it in a mono 7.1 mode, where all 7.1 speakers are used and use the same audio. Mono does not mean one speaker, under most cases, it simply means one audio source/channel. Mono 7.1 or stereo copied to all 7.1 speakers is actually quite popular when using a 7.1 system for music.

jarrod1937

11-10-08, 12:12 PM

How does your personal feelings towards PLIIx refute the fact that 7-channel processing doesn't send "the same audio" to each speaker?

Sanjay
His point was that you can not attempt to produce 100% discrete audio with an original 2 channel source without comprimising the source.

tbrunet

11-10-08, 12:17 PM

Coupled with your comment regarding a simple sin wave vs complex sound fields.

sdurani

11-10-08, 01:38 PM

As already stated test signals are a bit different in these matters than complex audio.A test signal is merely an easy way to demonstrate that the same audio is not sent to each speaker, the opposite of what you claimed. I mentioned the source so that folks could try it for themselves and not have to take my word for it. Discrete by its very definition means "unique"/separate/on its own. Saying there is not freuqncy or audio content overlap on any speaker is saying that the audio is 100% discrete.Discrete channels, at least as the term is used in audio, doesn't simply mean no frequency or audio content overlap. Old mono soundtracks are often delivered on DVD as DD 2.0 tracks. Are you saying those 2.0 tracks are not two discrete channels just because they contain the same content?

Again, surround processing yields matrix derived channels, with unique information steered to each channel. No one claimed they were discrete channels. I was merely attacking your original arguement that more equals better, which it does not, while asserting that a fuller range speaker with a flatter frequency response is better. You can argue otherwise, but you're still incorrect. Some things, in a subjective topic, are simply not subjective.So you're saying that my subjective preference is "incorrect", but your subjective preference is objectively better? Are you next going to tell me that chocolate tastes objectively better than vanilla, even though I prefer the latter? You're incorrect that more speakers equals a better soundfield, as interference on varying frequencies will actually produce comb filtering or flatout nulls in portions of the room, obviously not helping the sound field, which of course is aggregated by (an assumed) untreated room.I pointed out things that more speakers can accomplish that are not possible with fewer speakers. The simplest example was where two lesser quality speakers can create a stereo soundstage that one higher quality speaker cannot. I then went on to say that these advantages qualified as better for me (you even acknowledged that I was stating my personal preference).

However, you seem unwilling to tolerate the idea that others may have different priorities from you when it comes to what they like in audio, asthough your personal preference somehow trumps what others prefer.

As for the idea that more speakers means "interference on varying frequencies will actually produce comb filtering or flatout nulls in portions of the room", read some of the Harman white papers by Toole/Welti/Olive on speaker and subwoofer placement. They demonstrate how more speakers can actually improve the soundfield, both for directionality and consistent bass across the room. For comb-filtering and nulls to be as problematic as you describe, the same sound would have to be coming from multiple speakers, which is not the case. Along with that i must say, "But let's not pretend that you were originally suggesting the saved money be spent on anything other than speakers." Is a bit childish, conversations evolve, so do debates... no one is pretending anything.If you had acknowledged that you were changing what you suggested originally, then I wouldn't have taken issue with it. Instead, you wrote: "What i suggested originally and still stand by it is that you can save money by going 5.1 rather than 7.1 and then better spend those savings on other areas or better speakers to improve the audio." Why would you say that "other areas" was part of your original suggestion when it clearly wasn't? So far you seem to be argueing for the sake of arguring, i say give it up and attempt to actually help the original poster in his quest for good audio.I have made separate posts to the OP, answering his questions where I felt I could. He already seems to have taken one piece of advice (sticking to a 5.1-speaker layout if the listening area is at/near the back wall).

Helping the OP doesn't mean I have to give up replying to other posts that I take issue with. In your case, it was the notion that "Fewer better quality speakers are always better than more lesser quality speakers." Giving specific examples of where it's not "always" better is not arguing for the sake of arguing.

Sanjay

HDgeneration

11-10-08, 02:25 PM

Do HTIB come with receivers? just wondering. Also what are the Specs for a Surround Sound System needed to get a excellent sound? .....Thanks.

sdurani

11-10-08, 02:46 PM

There is some audio overlap on two or more speakers in a true 7.1 processed sound stream.There can be some audio overlap, especially during pans, whether listening to matrix derived 7.1 or discrete 7.1 sources. That doesn't mean "the same audio" is sent to all speakers. If that were the case, pans wouldn't be possible. Mono does not mean one speaker, under most cases, it simply means one audio source/channel.Depends on the receiver or pre-pro. For example, on my processor, the Mono mode uses one speakers (irrespective of how many channels were in the original signal) while the Mono Surround mode copies that mono signal to all speakers.

But what does that have to do with surround processing? Are you trying to say that there is a mode where you can force the same signal to multiple speakers in order to unnecessarily create comb-filtering artifacts? By that logic, I could place the calibration microphone in the corner to prove that room correction doesn't work. [His point was that you can not attempt to produce 100% discrete audio with an original 2 channel source without comprimising the source.Actually, his point is to follow me from thread to thread, posting random comments. (Check his posting history.)

Besides, no one said that surround processing produces "100% discrete audio". Just that the same audio is not sent to each speaker, and I've mentioned how folks can demonstrate that for themselves.

Sanjay

sdurani

11-10-08, 02:52 PM

Do HTIB come with receivers?Yes, they typically do. If you're interested in the Onkyo 606, check out their HT-S6100 or HT-S7100 HTiBs (the receiver looks pretty similar). Personally, I would still get separate speakers and receiver instead of a HTiB, picking the Onkyo 706 over the 606. The Audyssey room correction EQs the subwoofer with the 706 but doesn't with the 606.

Sanjay

jarrod1937

11-10-08, 04:02 PM

There can be some audio overlap, especially during pans, whether listening to matrix derived 7.1 or discrete 7.1 sources. That doesn't mean "the same audio" is sent to all speakers. If that were the case, pans wouldn't be possible. Depends on the receiver or pre-pro. For example, on my processor, the Mono mode uses one speakers (irrespective of how many channels were in the original signal) while the Mono Surround mode copies that mono signal to all speakers.

But what does that have to do with surround processing? Are you trying to say that there is a mode where you can force the same signal to multiple speakers in order to unnecessarily create comb-filtering artifacts? By that logic, I could place the calibration microphone in the corner to prove that room correction doesn't work. [Actually, his point is to follow me from thread to thread, posting random comments. (Check his posting history.)

Besides, no one said that surround processing produces "100% discrete audio". Just that the same audio is not sent to each speaker, and I've mentioned how folks can demonstrate that for themselves.

Sanjay
Dear lord... I mean no disrespect, but you don't seem to be understand english too well.
In the very same sentence from me that you quoted i stated very specifically, "two or more" , how in the hell does two or more mean " "the same audio" is sent to all speakers." Two or more, means starting at a minimum of two speakers producing the same audio, with a possibility of more. In panning, you will reach a point where there is 100% the exact same audio between the origin speaker and the destination speaker for which the pan was going to. That is because as it pans from one speaker to the other, it fades from one speaker to the other, otherwise we would hear a gap. When this happens, you can have possible interference from the pan fade point where the audio is the same and of equal magnitude and contains frequencies whos wavelengths are 1/2 or more of that of the spacing between the origin and destination speaker.

"Besides, no one said that surround processing produces "100% discrete audio". Just that the same audio is not sent to each speaker"
This is almost laughable, again no offense meant. I just gave the definition of what discrete means, but perhaps i'll copy it directly from dictionary.com:
"1. apart or detached from others; separate; distinct"
Whats most amusing is you say that the audio is distinct but not discrete, they are synonyms! If the same audio is not sent to each speaker, then the same audio is not repeated on more than one speaker, therefore the audio is discrete... If that is how you want to describe it, it has to be considered discrete.

"
But what does that have to do with surround processing? Are you trying to say that there is a mode where you can force the same signal to multiple speakers in order to unnecessarily create comb-filtering artifacts? By that logic, I could place the calibration microphone in the corner to prove that room correction doesn't work. [Actually, his point is to follow me from thread to thread, posting random comments. (Check his posting history.) "
Whats funny is you seem to be in agreement with me on this but don't realize it. When i stated that, i was talking about how having the same audio produced by all speakers will definitely be a worst case scenario for interference, and therefore the worst for a stable sound field. An this was also coupled with the fact that 7.1 speakers, this will result in a worse sound field than a 5.1 sound system. My only point was to illustrate that often times people do enjoy listening to their music with the audio going through all of their speakers rather than have it go through the 7.1 matrixing. And if they do this on a 7.1 it will result in a worse sound field than a 5.1 system, and of course this is added with the assumed untreated acoustic space. Obviously the point of bringing up this topic, was again, to debate against what you stated that more speakers equals a more stable sound field. This can be true, but the environment and use has to be specific for it to be so.

sdurani

11-10-08, 05:24 PM

In panning, you will reach a point where there is 100% the exact same audio between the origin speaker and the destination speaker for which the pan was going to. ...When this happens, you can have possible interference from the pan fade point where the audio is the same and of equal magnitude and contains frequencies whos wavelengths are 1/2 or more of that of the spacing between the origin and destination speaker.[/i]And this momentary, transitory "point" in the middle of a pan is what will "produce comb filtering or flatout nulls in portions of the room" that you're making such a big deal about? Hardly a concern, considering how quickly the moment passes.

By comparison, consider a situation where critical content is overlapped for the entire length of a program. If you watch a movie or listen to music with 2 speakers across the front, the most important sounds (dialogue, vocals, instrument solos) are always being reproduced as a dual-mono overlap.

If we use a 3rd speaker, placed at the centre of the soundstage, those same sounds can now be reproduced as true mono instead of dual-mono. More speakers = less overlap = less comb filtering.

Best part, no matter where listeners are seated, they will always hear those sounds from the centre of the soundstage. More speakers = less phantom imaging = more stable soundstage. Whats most amusing is you say that the audio is distinct but not discrete, they are synonyms! If the same audio is not sent to each speaker, then the same audio is not repeated on more than one speaker, therefore the audio is discrete... If that is how you want to describe it, it has to be considered discrete.'Discrete' and 'distinct' are not synonyms when discussing audio.

For example: a Pro Logic decoder can produce different sounds from the left, centre, right & surround channels. Are you saying that those matrix derived channels have to be considered "discrete" just because they contain different content?

Another example: an old mono recording is released on CD using both channels. Does that CD no longer have two discrete channels of PCM since they both contain the exact same content? When i stated that, i was talking about how having the same audio produced by all speakers will definitely be a worst case scenario for interference, and therefore the worst for a stable sound field. An this was also coupled with the fact that 7.1 speakers, this will result in a worse sound field than a 5.1 sound system.Well, if your example of 7.1 is a worst case scenario of "having the same audio produced by all speakers", then my example of 5.1 is a worst case scenario where one of those echo-heavy DSP "Hall" modes are used to generate the surround sound. Seems only fair. And if they do this on a 7.1 it will result in a worse sound field than a 5.1 systemLikewise, if they use the DSP Hall mode to create 5.1, it will sound worse than 7.1. Obviously the point of bringing up this topic, was again, to debate against what you stated that more speakers equals a more stable sound field.It does. Which is why audio reproduction has gone from 1 speaker to 2 speakers to 5.1 speakers to 7.1 speakers and eventually beyond. If what you claimed were true, audio reproduction would be trending the other way.

Sanjay

sivadselim

11-10-08, 05:44 PM

His point was that you can not attempt to produce 100% discrete audio with an original 2 channel source without comprimising the source.There is (usually) plenty of audio overlap with a 2-channel stereo recording played back, in stereo, with 2 speakers. It is still a discrete format. 'Discrete' is something that is specifically encoded. And, yes, that would include mono info encoded identically into the L/R channels. There are still 2 discrete channels of info. Processing can't really create 'discrete' satisfactorily if it is not there to begin with.

Whether the source is "compromised" when a 2-channel source is matrixed is subjective. Some people like that. Many hate it. Personally, I think that 2-channel material should be reproduced as intended. And some 2-channel material IS actually intended to be matrixed.

I would agree that there is really no disagreement over what is discrete and what isn't in this discussion.

jarrod1937

11-10-08, 06:02 PM

And this momentary, transitory "point" in the middle of a pan is what will "produce comb filtering or flatout nulls in portions of the room" that you're making such a big deal about? Hardly a concern, considering how quickly the moment passes.

By comparison, consider a situation where critical content is overlapped for the entire length of a program. If you watch a movie or listen to music with 2 speakers across the front, the most important sounds (dialogue, vocals, instrument solos) are always being reproduced as a dual-mono overlap.

The panning was just one of many examples. My whole point of mentioning and separating audio content from frequency content (read back a few posts) is that you don't need identical audio to have interference. For example, you could very easily have identical frequencies being produced by many of your speakers, which, even though the audio content as a whole is different, will still have frequency overlapping. Getting even more complex, you can have interference being produced by one frequency from one speaker and an entirely different frequency from another speaker. This is being every frequency has its own wavelength, which has parts of its period that can lineup with other frequencies after so many cycles. Because of this, it does not matter how many unique channels of audio is used, the more speakers always will equal more comb filtering.

Well, if your example of 7.1 is a worst case scenario of "having the same audio produced by all speakers", then my example of 5.1 is a worst case scenario where one of those echo-heavy DSP "Hall" modes are used to generate the surround sound. Seems only fair. Likewise, if they use the DSP Hall mode to create 5.1, it will sound worse than 7.1.

If you'll excuse me, your logic in this entire section confuses me.

It does. Which is why audio reproduction has gone from 1 speaker to 2 speakers to 5.1 speakers to 7.1 speakers and eventually beyond. If what you claimed were true, audio reproduction would be trending the other way.

Sanjay
Just because they're moving in a direction does not mean its better. Not to mention i'm sure they're also well aware of the same difficulties i've mentioned, which they have to deal with in their engineering. Although your conclusion in " If what you claimed were true, audio reproduction would be trending the other way." is incorrect. There are sciences behind these decisions, one of which maps the sound field distortion trade off to the sound field improvement. I have no doubt you will get a more defined sound field with more speakers, but you must balance this with the issues discussed above.

sivadselim

11-10-08, 06:40 PM

The panning was just one of many examples. My whole point of mentioning and separating audio content from frequency content (read back a few posts) is that you don't need identical audio to have interference. For example, you could very easily have identical frequencies being produced by many of your speakers, which, even though the audio content as a whole is different, will still have frequency overlapping. Getting even more complex, you can have interference being produced by one frequency from one speaker and an entirely different frequency from another speaker. This is being every frequency has its own wavelength, which has parts of its period that can lineup with other frequencies after so many cycles. Because of this, it does not matter how many unique channels of audio is used, the more speakers always will equal more comb filtering.Not that it is entirely relevant, here, but these artifacts and their direct and indirect manipulation and interplay are responsible for and essential to much of the percieved end-result, upon playback, of a discretely mixed soundtrack as well as one that is matrixed. Comb-filtering, for example, is a necessary "artifact". It is absolutely essential to how a pan is perceived. Sure, you can create it unintentionally and undesirably upon playback, but without it, you would not hear what an engineer intended, either. And it does not have to be intentionally mixed into a soundtrack. Comb filtering is just going to be there, always, intentional or not. It can also be intentionally and heavy-handedly mixed into a soundtrack; see flange effect. And it can be created by a single speaker or sound source, too, btw. Even a single speaker in the clock radio in your bedroom produces comb filtering. Comb filtering is, basically, essential to how we hear and interpret sound.

And someone may like the way their '7 channel stereo' setting sounds precisely BECAUSE of these artifacts.

sdurani

11-10-08, 07:16 PM

it does not matter how many unique channels of audio is used, the more speakers always will equal more comb filteringMore unique channels means less overlap, since sounds that used to be shared equally between two speakers can now be reproduced by a single speaker in between. Less overlap means less comb filtering. I have no doubt you will get a more defined sound field with more speakers, but you must balance this with the issues discussed above.So if someone prefers to accept the issues discussed above in order to have a more defined sound field, it is somehow not as objectively correct as your preference to give up a more defined soundfield for less of the issues that bother you?

Sanjay

jarrod1937

11-10-08, 08:13 PM

More unique channels means less overlap, since sounds that used to be shared equally between two speakers can now be reproduced by a single speaker in between. Less overlap means less comb filtering.

Read the whole part about frequency overlap, it has nothing to do with the unique channels and everything to do with the amount of speakers present. Now channels have an effect, but that was in the past discussion when we were talking precisely about exact audio being reproduced.

So if someone prefers to accept the issues discussed above in order to have a more defined sound field, it is somehow not as objectively correct as your preference to give up a more defined soundfield for less of the issues that bother you?

Sanjay
Read the word "balanced", you seem to read what you want and give it any type of spin you feel it should have, you'd make a great politician ;)
The point is balance of speakers to the distortion of their sounds. If you have 20 speakers, you'd certainly have breached that balance. 7.1 is close to breaching that balance, depending on your room setup. They are not particularly just effects that bother me, they bother most of the world who seeks quality audio. Comb filtering is one of the enemies of quality audio and is the main reason for room treatments. My point is to point out that unintended comb filtering, that we have no control over, is that of frequency interference from multiple speakers (read, it does not require exact audio). This is increased the more speakers you have, and this is something that must be balanced with the total amount of speakers. To argue that this effect does not matter is the equivalent of arguing that room treatments don't matter.
But of course if someone is willing to sacrifice their audio to increased comb filtering from more speakers.... well, that is their choice, and if they enjoy it, more power to them.

jarrod1937

11-10-08, 08:15 PM

Not that it is entirely relevant, here, but these artifacts and their direct and indirect manipulation and interplay are responsible for and essential to much of the percieved end-result, upon playback, of a discretely mixed soundtrack as well as one that is matrixed. Comb-filtering, for example, is a necessary "artifact". It is absolutely essential to how a pan is perceived. Sure, you can create it unintentionally and undesirably upon playback, but without it, you would not hear what an engineer intended, either. And it does not have to be intentionally mixed into a soundtrack. Comb filtering is just going to be there, always, intentional or not. It can also be intentionally and heavy-handedly mixed into a soundtrack; see flange effect. And it can be created by a single speaker or sound source, too, btw. Even a single speaker in the clock radio in your bedroom produces comb filtering. Comb filtering is, basically, essential to how we hear and interpret sound.

And someone may like the way their '7 channel stereo' setting sounds precisely BECAUSE of these artifacts.
Quite true. But the discussion here (as you said it was not entirely relevant) is to get rid of the excessive, unintended comb filtering. However, thank you for sharing that information, looked up the flange effect and found it interesting.

Kal Rubinson

11-10-08, 08:21 PM

More unique channels means less overlap, since sounds that used to be shared equally between two speakers can now be reproduced by a single speaker in between. Less overlap means less comb filtering. So if someone prefers to accept the issues discussed above in order to have a more defined sound field, it is somehow not as objectively correct as your preference to give up a more defined soundfield for less of the issues that bother you?

Read the whole part about frequency overlap, it has nothing to do with the unique channels and everything to do with the amount of speakers present.Nope. The comb filtering due to reproducing the same signal from displaced drivers is something that didn't exist at the original performance. The comb filtering due to the interaction of independent sources occurs at the performance (and everywhere in the real world) and its occurrence in reproduction is not a problem. Thus, an increase in the number of speakers, each producing discrete channel information is advantageous for many reasons.

jarrod1937

11-10-08, 08:51 PM

Nope. The comb filtering due to reproducing the same signal from displaced drivers is something that didn't exist at the original performance. The comb filtering due to the interaction of independent sources occurs at the performance (and everywhere in the real world) and its occurrence in reproduction is not a problem. Thus, an increase in the number of speakers, each producing discrete channel information is advantageous for many reasons.
You're correct. But isn't that assuming the comb filtering wasn't recorded by the mics during the performance? If the comb filtering wasn't, then i would agree that is advantageous as it is now reproducing the comb filtering that would have existed in real life, not to mention comb filtering can be used purposefully (as already mentioned) to create certain effects. However, what if the comb filtering was recorded already by the mics and now you're introducing more comb filtering, is that still advantageous in some way? Doubly producing the comb filtering that would have existed?

Kal Rubinson

11-10-08, 09:17 PM

You're correct. But isn't that assuming the comb filtering wasn't recorded by the mics during the performance? If the comb filtering wasn't, then i would agree that is advantageous as it is now reproducing the comb filtering that would have existed in real life, not to mention comb filtering can be used purposefully (as already mentioned) to create certain effects. However, what if the comb filtering was recorded already by the mics and now you're introducing more comb filtering, is that still advantageous in some way? Doubly producing the comb filtering that would have existed?You raise an interesting point. The only place the comb filtering is significant is at your ears. (Sorta like the tree falling in the forest, if you are not there, the sound of it is irrelevant.) If (and I mean if) the speaker channels represent the energy at each of 5 or 7 mic locations, each will reproduce whatever energy was present including any resulting from on-site comb filtering. With each as a source in the listening room, they will generate additional interactions, including additional comb-filtering, with the composite arriving at the ear. Will this reproduce what would have been at the ears if the listener were present at the performance? Highly unlikely but my point is that having some comb-filtered energy in each channel may not be deleterious.

youngho

11-10-08, 09:50 PM

Jarrod, you might be interested to know that Floyd Toole (former vice-president of acoustical engineering at Harman), Sigfried Linkwitz (designed a rather well-known crossover), and Tomlinson Holman (as in THX, helped develop the 5.1 and subsequent surround formats) all seem to disagree with you in terms of these early reflections and comb filtering issues that seem to concern you so greatly. Toole did an extensive amount of research into listener preferences, and although most listeners do share your "objective" preferences when it comes to loudspeakers, the fact is that there are many expensive speakers that deviate significantly from extended frequency response (see so-called "wideband" or single driver speakers), smooth frequency response (the continuing popularity of vintage speakers, many horn designs and also single driver speakers), and even directivity (a significant issue for first-order crossovers) in favor of euphonic colorations or other aspects of the sound that they find subjectively pleasing. Fans of these speakers would argue vigorously against your oxymoronic combination of the words "objectively" and "better," particularly when there doesn't seem to be a broad consensus about what "better" or even what "accurate" means when it comes to audio.

"The point is balance of speakers to the distortion of their sounds. If you have 20 speakers, you'd certainly have breached that balance. 7.1 is close to breaching that balance, depending on your room setup. They are not particularly just effects that bother me, they bother most of the world who seeks quality audio."

You clearly have a deep and profound point here, but you're failing to get it across. Can we assume you've gone to USC and actually heard a 20 channel setup? What bothered you so much about a properly setup 7.1 system? Did you run screaming from the room because of transient comb filtering at specific frequencies that you were able to identify when listening to broadband pink noise (few listeners can do so when listening to music)?

Comb filtering is one of the enemies of quality audio and is the main reason for room treatments."

See above. Even better, read and learn. There is a reasonable amount of psychoacoustic research suggesting that lateral reflections are actually beneficial to the enjoyment of reproduced music for most listeners, although probably not those involved in the production of said music, and the psychoacoustics behind THAT only underscores the individuality of listener preferences.

jarrod1937

11-10-08, 10:42 PM

"The point is balance of speakers to the distortion of their sounds. If you have 20 speakers, you'd certainly have breached that balance. 7.1 is close to breaching that balance, depending on your room setup. They are not particularly just effects that bother me, they bother most of the world who seeks quality audio."

You clearly have a deep and profound point here, but you're failing to get it across. Can we assume you've gone to USC and actually heard a 20 channel setup? What bothered you so much about a properly setup 7.1 system? Did you run screaming from the room because of transient comb filtering at specific frequencies that you were able to identify when listening to broadband pink noise (few listeners can do so when listening to music)?

Well, to me comb filtering is not that difficult to identify or hear, even when listening to music. It would seem more difficult to identify when using pink noise, wide or limited band. Though, i am also not claiming to have god like hearing or anything either (just to stop some people in their tracks). My point is that comb filtering is introduced the more speakers you have, and if you want more than just a sweet spot, you'll want to set a limit for the speaker count. I believe there are some ways to engineer the physical listening environment to help minimize this, but i have yet to see any particular solutions. Not to mention there still is the whole debate on how many individual channels and speakers a person can actually distinguish between, which might make an increasing speaker count a moot point after a while.
Although, i do want to respond to the whole "objective" thing. I stated earlier that my way of judging quality audio was "more" objective than most others. I must have not stated that right as some here seem to think i mean its totally objective. If you look back, i stated "I suppose this is still an opinion and so is up for judgment," in essence my point was to explain that i feel my methods of measuring certain qualities are more objective (emphasis on more) than other techniques people seem to use. Though, perhaps even that statement is subjective :confused: :D
And yes, i am well aware certain high end speaker do the opposite of creating a flat response, and so on. I've seen plenty of speakers like these, usually emphasizing the higher frequencies. Which i will admit can really sound good, for a bit, but get tiring after a while. Others also introduce "color" as some call it, since i'm a purist i feel whatever was not in the recording should not be played back to my ears. However, as i have stated before, if people like it, well, good for them :) . I'm not some audio nazi that states you MUST have speakers a certain way if you enjoy it another way. Although i feel there are definite ways of measurement that can lead to better quality audio, the complex realm of physcoacoustics and physiology variations can cause a stray from these.

sivadselim

11-11-08, 12:48 AM

ANY sound that is reflected off of ANY surface has been comb filtered when it reaches your ears. Your ears themselves comb filter sounds.

Raymond Leggs

11-11-08, 12:57 AM

ANY sound that is reflected off of ANY surface has been comb filtered when it reaches your ears. Your ears themselves comb filter sounds.

so you shouldnt even worry about comb filtering seince your ears make music sound worse? :rolleyes:

youngho

11-11-08, 07:48 AM

Jarrod, broadband noise is actually much more revealing of colorations than music is, as experienced listeners and acousticians know. Many experiments have demonstrated that the audibility of comb filtering is highest in highly dampened rooms but rapidly disappears when more reflections come from more directions. There are also psychoacoustic reasons (critical bands, binaural hearing, spectral adaptation) why comb filtering is minimized by the human auditory system. Concert halls have the most and "worst" comb filtering effects because of SO many reflections from SO many surfaces, yet most of us enjoy listening to performers play in them, rather than in anechoic chambers that might otherwise preserve the purity of the original wavefront. Concerns about comb filtering introduced by the addition of additional channels themselves should be alleviated by equidistant spacing of them from the central listening position, and concerns about the audibility of comb filtering from the reflections from the additional channels should be reassured by years of psychoacoustic experiments.

I do agree that the decision to place more value on certain measurements than others is still rather subjective, which is why different speaker designers have different goals, whether it's on-axis performance, ability to reproduce a squarewave impulse response, power response, directivity, efficiency uber alles, etc. However, you would probably enjoy reading some of Toole's white papers (available on the Harman website) looking at their research into listener preference.

sdurani

11-11-08, 10:59 AM

Read the whole part about frequency overlap, it has nothing to do with the unique channels and everything to do with the amount of speakers present.I did read the part about frequency overlap, especially where you said:

"For example, you could very easily have identical frequencies being produced by many of your speakers, which, even though the audio content as a whole is different, will still have frequency overlapping. Getting even more complex, you can have interference being produced by one frequency from one speaker and an entirely different frequency from another speaker."

What you're saying is that even if we have completely different content (e.g., a male vocal and a female vocal) going to two separate speakers, there will be enough "frequency overlap" between those two dissimilar signals for comb filtering to be a concern. If this really were a problem, then the only solution would be to use one speaker. Even 5.1 speakers reproducing 5.1 discrete channels would be severly problematic by comparison. Or does it not really become a problem until you reach, say, 7.1 speakers?

BTW, having those two signals in one channel/speaker would allow some frequencies to electonically overlap more precisely than they ever would have acoustically (because two speakers could never be so perfectly equidistant from the listener). So you end up with a form of electronic comb filtering instead of acoustic comb filtering. This gets worse as more frequencies electronically overlap each other in one channel rather than being spread over multiple channels (which would minimize the effect). Why aren't you concerned with those frequency overlaps? The point is balance of speakers to the distortion of their sounds.What makes you think that where you choose to strike that balance is "always better" (per your original post) than the balance that someone else chose? If you have 20 speakers, you'd certainly have breached that balance. 7.1 is close to breaching that balance, depending on your room setup.Have you heard an Ambisonic set-up using 16 or 32 speakers? Have you heard Holman's 10.2 speaker set-up? I wish you would, before passing judgement on the effect of more speakers.

And how did you arrive at the notion that 7.1 is on the cusp of that balance? Why not 5.1 or 9.1?

Sanjay

jarrod1937

11-11-08, 12:32 PM

BTW, having those two signals in one channel/speaker would allow some frequencies to electonically overlap more precisely than they ever would have acoustically (because two speakers could never be so perfectly equidistant from the listener). So you end up with a form of electronic comb filtering instead of acoustic comb filtering. This gets worse as more frequencies electronically overlap each other in one channel rather than being spread over multiple channels (which would minimize the effect). Why aren't you concerned with those frequency overlaps?
I am mostly done talking with you on the same subject, because we're going around in circles. However, i am curious about your above point. Do you have any particular sources for this effect?
I own an oscilloscope, for which i use to view the true signal of electronics. Here, if you play a 1 kHz test signal (be it square or sine) you'll see a single ac signal with a frequency of 1 kHz. However, if you play a complex waveform like music, you'll see the higher frequencies piggy backing on the lower frequency signals, almost like what you'd see when a signal mixes with a carrier/subcarrier wave in telecommunications. Technically speaking, each waveform is a component of this mixed waveform, which is where crossovers come in handy. The signal is split into however many drivers yu have, and then each signal is filtered out using unique circuitry that filters out certain ac frequencies that the driver does not need. In otherwords, there should be no electronic comb filtering occurring. Even my oscilloscope is easily able to give me the spectrum readings of the complex waveform, illustrating that it too can separate the frequencies without difficulty. The process is is similar to multiplexing, if done right multiplexing can easily mix multiple signals in one transmission line, and be able to 100% separate those signals on the other end.

sdurani

11-11-08, 01:55 PM

i am curious about your above point. Do you have any particular sources for this effect?Sure. One example is this article (http://www.moultonlabs.com/index.php/more/about_comb_filtering_phase_shift_and_polarity_reversal/) from Moulton Labs, which discusses electronic comb filtering vs acoustic comb filtering.

Sanjay

Kal Rubinson

11-11-08, 02:04 PM

sivadselim

11-11-08, 02:09 PM

so you shouldnt even worry about comb filtering seince your ears make music sound worse? :rolleyes:

No. You should only be concerned with added, duplicate and/or unnecessary comb filtering. Those from the source and from your ears are unavoidable (and necessary). Arranging processing and/or setup to create more is to be avoided.Thanks. :o

A point being, Raymond, that comb filtering is absolutely necessary for you to not only perceive 'natural' sounds properly, but to also perceive the 'artificial' sound produced by your speakers properly, as intended.

jarrod1937

11-11-08, 02:16 PM

Sure. One example is this article (http://www.moultonlabs.com/index.php/more/about_comb_filtering_phase_shift_and_polarity_reversal/) from Moulton Labs, which discusses electronic comb filtering vs acoustic comb filtering.

Sanjay
Correct me if i'm wrong, but isn't that related to the recording and mixing of the audio? Which, definitely can easily introduce comb filtering, into the source. But assuming the source material was mixed correctly, does electronic comb filtering still occur in a multiplexed signal as you state?

tbrunet

11-11-08, 02:22 PM

.. Even my oscilloscope is easily able to give me the spectrum readings of the complex waveform, illustrating that it too can separate the frequencies without difficulty. .jarrod,

Actually those time vary events like complex music waveforms seen on your oscilloscope are fundamentally harmonic combinations. I'm sure you already know these complex waveforms can be decimated with Fourier transforms and displayed (spectrum analyzer) as discrete frequencies, each with their relative magnitude.

http://csunix1.lvc.edu/~snyder/1ch5.html

jarrod1937

11-11-08, 02:31 PM

jarrod,

Actually those time vary events like complex music waveforms seen on your oscilloscope are fundamentally harmonic combinations. I'm sure you already know these complex waveforms can be decimated with Fourier transforms and displayed (spectrum analyzer) as discrete frequencies, each with their relative magnitude.

http://csunix1.lvc.edu/~snyder/1ch5.html
Yes, i've studied the fast fourier transforms and the like. Although i am not an expert in that area, just personal studies. Thank you for the link though, will give it a read for any new information.

tbrunet

11-11-08, 03:01 PM

Just a final comment on the subject of comb filtering. Musical (studio productions) sound fields are in fact contrived events, the mixing engineer is NOT attempting to create (listening position) point source accuracy or directionality but rather virtual sound field that may have intentional unnatural (acoustical) characteristics.

Also if a 5.1 encoding is matrix for 7 speaker surround configuration.. artifacts are unavoidable. In the real world you don't get something for nothing. If the opposite is done i.e. matrix 7 channels into a 5 channel payload, there would be no way to recover 100% of the original content.

sdurani

11-11-08, 04:42 PM

But assuming the source material was mixed correctly, does electronic comb filtering still occur in a multiplexed signal as you state?By "mixed correctly", do you mean 'checked for electronic comb filtering' (as the author of the article warns mixers to do)? If so, then it shouldn't occur in any of those recordings. But that's a circular premise. With the staggering amount of audio (movies, music, games, etc) that goes through mixing studios world wide, you can't start with the assumption all the source material was mixed correctly and checked for problems.

Is it something worth worrying about? Probably as much as the phenomenon you describe, where one frequency from one speaker and an entirely different frequency from another speaker line up so perfectly at your ear after so many cycles that it results in interference and comb filtering. And how often is that going to happen?

Sanjay

jarrod1937

11-11-08, 04:54 PM

By "mixed correctly", do you mean 'checked for electronic comb filtering' (as the author of the article warns mixers to do)? If so, then it shouldn't occur in any of those recordings. But that's a circular premise. With the staggering amount of audio (movies, music, games, etc) that goes through mixing studios world wide, you can't start with the assumption all the source material was mixed correctly and checked for problems.

Is it something worth worrying about? Probably as much as the phenomenon you describe, where one frequency from one speaker and an entirely different frequency from another speaker line up so perfectly at your ear after so many cycles that it results in interference and comb filtering. And how often is that going to happen?

Sanjay
I never stated that we should worry about all comb filtering. However, you might as well limit the amount of unintentional comb filtering that we have control over.
You really need to study what i've been saying, you comment of "And how often is that going to happen?" shows you don't entirely understand what i am discussing, because it in fact happens a lot.
http://id.mind.net/~zona/mstm/physics/waves/interference/twoSource/TwoSourceInterference1.html
When you have two sources playing an identical audio source, you will get a similar pattern like in that link. When you have two sources playing a complexity of a lot of mixed frequencies you'll get a pattern like in that link, but with alternating interference as the frequencies wavelengths take a few of its cycles to reach the point of being out of phase to interact with other lower or higher frequencies. The more sources you have, the more pockets of interference that will occur in the sound field.

youngho

11-11-08, 07:41 PM

jarrod1937

11-11-08, 08:06 PM

Jarrod, unless you have two or more channels playing broadband noise, it's extraordinarily unlikely that you'd have a steady-state phenomena like that depicted in that Java applet. Furthermore, unless you're running around the room or listening to all positions simultaneously because of God-like status, the applet is essentially irrelevant. Like nodes and antinodes resulting from room modes, interference patterns are not relevant if not present at the listening position. As long as all channels are equidistant (or appropriate group delay is introduced to compensate for distance differences), any comb filtering introduced by additional channels, even if reproducing the same signal, should be minimal, approaching zero as true equidistance is achieved.

If i am proven 100% wrong i will admit it. If i don't admit i'm wrong, it is because i have not been given sufficient proof to change my own opinion/understanding of the matter. For example, i still don't understand how you can say that the interference will be irrelevant. Yes, the java applet was not the best example, but i attempted to use it as a visual aid, obviously its not like speakers in the sense that its omni directional. Distance of the speakers is rather irrelevant here as as this would do is change which frequencies interact. When these frequencies do interact, they will do so in a predictable pattern in predictable pockets. Just as nulls can exist in specific spots in a room, this type of interference can exist and create nulls between many different combination's within a room. In otherwords, its like a comb filtering from hell ;) But it can and will create nulls or extreme peaks on a large variety of frequencies, which can very likely affect multiple possible listening positions. It can be observed that a certain frequency has multiple frequencies that, if met with the original frequency, will produce alternating interference patterns. The same thing happens with multiple audio sources producing a variety of frequencies. Again, the final result are pockets, or zones, of peak or null interferences in the acoustical space. Again, which very well could be in the listeners position, you can not say otherwise without knowing how many sources there are, or the actual acoustics of the space, or where the listeners position actually resides. If this is some how incorrect, then please produce a sufficiently complex explanation or known theorem as to why. I will admit i'm wrong if so, but i don't go around believing everything i hear from some guy on a forum, for me to change my mind and understanding, i require at least one very credible or two somewhat credible sources to backup their claim.

p.s. I did see your reply before you edited it. I do agree, but again, i just feel i have not been sufficiently proven wrong.

Raymond Leggs

11-11-08, 08:54 PM

Thanks. :o

A point being, Raymond, that comb filtering is absolutely necessary for you to not only perceive 'natural' sounds properly, but to also perceive the 'artificial' sound produced by your speakers properly, as intended.

Thanks for clearing that up, both you and kal, I was Confused ( :confused: )

jarrod1937

11-11-08, 09:51 PM

After some more thinking, one does have to wonder about the effect of the multiple frequency interference. It obviously is something that will exist if there are two or more sources of frequencies. But because of the fact that it will only occur on a variation of the original frequency meeting with a secondary equivalent or near equivalent frequency, each having a different wavelength, would therefore cause a different static hot spot for each combination of the original and the secondary. In other wards, there are in fact multiple areas where there will be interference of some sort with the original. Combine this with the fact that there are multiple frequencies with a wavelength that would allow it to be interfered with, you end up having all frequencies having multiple interference zones/hot spots, in essence giving every zone within the acoustic space an interference issue of some sort with at least one frequency.
Now, the tricky part is the fact that these interference zones are in fact larger, and so fewer relatively speaking, with fewer speakers. And so, are smaller but more plentiful with more speakers... In essence, it seems that actually, at least in this situation, neither fewer or more speakers has an advantage in this problem.
Now the question is, could it be argued that this is part of the nature of sound and is needed to reproduce sound naturally? Or is it some unnatural addition to the sound added by our artificial means on producing audio?

p.s. I have not always been debating in this topic just to argue, as some here seem to think, i just rather enjoy discussing the more obscure parts of audio.

Kal Rubinson

11-11-08, 10:15 PM

After some more thinking, one does have to wonder about the effect of the multiple frequency interference. It obviously is something that will exist if there are two or more sources of frequencies. But because of the fact that it will only occur on a variation of the original frequency meeting with a secondary equivalent or near equivalent frequency, each having a different wavelength, would therefore cause a different static hot spot for each combination of the original and the secondary. In other wards, there are in fact multiple areas where there will be interference of some sort with the original. Combine this with the fact that there are multiple frequencies with a wavelength that would allow it to be interfered with, you end up having all frequencies having multiple interference zones/hot spots, in essence giving every zone within the acoustic space an interference issue of some sort with at least one frequency.
Now, the tricky part is the fact that these interference zones are in fact larger, and so fewer relatively speaking, with fewer speakers. And so, are smaller but more plentiful with more speakers... In essence, it seems that actually, at least in this situation, neither fewer or more speakers has an advantage in this problem.
Now the question is, could it be argued that this is part of the nature of sound and is needed to reproduce sound naturally? Or is it some unnatural addition to the sound added by our artificial means on producing audio?It is unavoidable both at live performances and with reproduction. However, I am not sure it is going to be relevant in determining an optimum number of speakers or whether more or less is better.

We live in is a soup of complex pattern of sound interactions that approaches randomness and, I think, what we want to avoid is a simpler, more discrete pattern. I think we would find the latter unnatural. OTOH, isn't that what poor room acoustics does? ;)

youngho

11-11-08, 10:22 PM

Deleted as per tbrunet's request

jarrod1937

11-11-08, 10:45 PM

Alright, i do admit i was wrong on some points. However, others i feel i am correct on still, but perhaps, by my observation of your interpretation, it seems to be because of my imprecise writing.
Although i do feel you have taken some points to the extreme,
"Wrong. One extraordinary speaker cannot produce the stereo illusion that two extremely good speakers can."
In context of my statement, i was discussing 5.1 vs 7.1. In that context, the differences are diminished considerably, compared to mono vs stereo.
Other parts i see things like
"These are beat frequencies, and they represent a different acoustic phenomena."
Why wait until now to tell me this? I am here and ready to learn, so don't hold back such information. If you saw this earlier, i urge you to not hesitate in telling me, that way i can learn and move on.
The rest of your reply consists of saying i conceded a point, but never directly admitted i was wrong. Is it of incorrect mindset to not feel the need to admit i was wrong if the point was conceded?

tbrunet

11-12-08, 09:44 AM

By "mixed correctly", do you mean 'checked for electronic comb filtering' Said “comb-filter issues” are really just mono or stereo down mix artifacts and i.e. a good 5.1 mix that doesn’t down mix well does NOT necessarily correlate with a mix that needs fixing or has comb filter issues.

In true discrete multi channel surround formats there's no steering interaction between the channels.

sdurani

11-12-08, 01:46 PM

I never stated that we should worry about all comb filtering.Where did I say you did? If fact, I pointed to a specific example of yours, one that I felt was as inconsequential as worrying about electronic comb filtering. The more sources you have, the more pockets of interference that will occur in the sound field.Just like what we hear all the time in the rear world. We live in a sea of comb filtering, which our ear/brain mechanism filters as a normal aspect of hearing, not finding it objectionable unless it is very directional. This is why 2 centre speakers will have audible lobing as you move left to right on your couch, but an array of 10-12 surround speakers will sound consistent whether you sit near the front or back of a theatre. You would think that the surround array would create so much interference that it would be a problem. Instead, the interference is so random that it becomes part of the background. I have not always been debating in this topic just to argue, as some here seem to think...No one here has accused you of arguing for the sake of arguing. In fact, I think you're the only one that has made that accusation. There's a reason why some of us have been taking the time to write detailed replies to your posts.

Sanjay

sdurani

11-12-08, 02:15 PM

In true discrete multi channel surround formats there's no steering interaction between the channels.The human head weighs 8 pounds.

Sanjay

tbrunet

11-12-08, 02:20 PM

Yes sir if you say so!

Sanjay can you please continue your dissertation on comb filtering?

sdurani

11-12-08, 02:21 PM

Sanjay can you please continue your dissertation on comb filtering?What would you like me to say?

Sanjay

tbrunet

11-12-08, 02:26 PM

Maybe you could link it’s (comb filtering) profound effect on surround music mixes that are optimized for surround listening only, without regard for how they might sound when "downmixed" to stereo or mono?

sdurani

11-12-08, 02:30 PM

tbrunet

11-12-08, 02:32 PM

Could you describe this "profound effect"? What does it sound like? Your the expert..right?

sdurani

11-12-08, 02:35 PM

Your the expert..right?If you say so. Again, what does this profound effect sound like?

jarrod1937

11-12-08, 05:11 PM

Btw, youngho, on this subject i am still not clear:

Equidistant spacing (or appropriate delay) will obviate any such interference for the central listening position. I hope you will finally concede this point.
I know that you can set a delay so that the audio sources near you will produce sound within the near the same time frame as the sound sources further from you actually reach your ears. And i know that spacing can help with interference issues with comparing two sound sources.
However, i am still unclear on how this actually affects my argument? The kind of interference (whether or not its called comb filtering is irrelevant) that i was referring to is not affected by either delay nor distance of the speakers of their relation to the listener.
If these two items do actually cause a difference, then i'd be interested to know, just out of curiosity's sake.
If your above quote was in reference to comb filtering in particular, it should be noted that i never argued it didn't help with comb filtering. And if i did it was because i was under the impression these two types of interferences went by the same name. As such, when i argued it made no difference i was arguing so in reference to the now known official name of "beat frequencies" as you called them.

edit: I also feel your post verges on nitpicking at times. All i requested in my post was evidence that i was wrong by some credible sources, and finally (not sure why it wasn't done sooner) some were presented to me, and so i did admit i was wrong on those points.

When you were corrected on this point by Sivadselim, you did not admit that you were wrong.
When he corrected me, i did not argue against that anymore. Do you somehow feel everyone "Must" admit they're wrong every single time they're wrong? If you don't know, if someone is corrected and they no longer argue that point anymore, that is usually sufficient under most cases.

youngho

11-12-08, 09:35 PM

Deleted as per tbrunet's request

jarrod1937

11-12-08, 09:52 PM

Thank you for the clear and well written post. I will read it indepth tomorrow, at which point i hope to have a clearer understanding of the topics at hand.
"remote possibility that you're actually learning something" You're misunderstanding. While i may not jump out and say i was wrong, i have learned quite a lot from this thread alone. Although i seem to not be able to put forth my thoughts correctly, which is evident if no one understands, at this point what interference i speak of. Perhaps i'll do some more research to find its actual name.
Along with this, i must say, don't judge me primarily on my imprecise writing, we humans are much more than our writing skills ;)

p.s. Out of curiosity, what is your profession?

tbrunet

11-13-08, 09:17 AM

Mr.youngho,

If your time one this public forum somehow subtracts from other more pressing and or important matters.. please spare us just how “tedious” this has all become for you? Thanks in advance!

Jarrod has been quit humble IMO and still you and Sanjay manifest the obligatory trait (on AVS) of nit picking post to death and require repeated over and over how you are right and “I” was wrong.

Please note as I said above matrixing (creating) new channels from a non-matrixed payload will result in compromising the intended originally mixed perceptual sound field. Take for example producing a center channel from a given stereo mix. Considering how MOST sound fields for music are contrived, just by matrixing a new center (channel) can reduce the apparent width of the front stereo spread, and the apparent spaciousness of the music will be correspondingly lower. As I said earlier you don’t get something for nothing in the real world. If that were NOT the case, one could magically matrix 7 channels into five channel payload.. but yet somehow still manage to propagate all seven perfectly aka transparently.