Can you have a State of the Art home theater without room correction? - Page 4 - AVS Forum
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post #91 of 190 Old 12-18-2011, 06:26 PM
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Jeff

If you show up for the demo in January I would suggest you bring a bib with you...............

Because you will be dribbling all over your self while your here.

Dan has put hours into this show down, and to hear it; is to make normal men dribble and weep.
We did a demo over the weekend for someone and it was sad. The poor SOB couldn't decide what would hurt more; the 60K his wife would make him spend for a Kaliedescape system or the 60K it was going to cost him to upgrade his existing audio setup. Just sad ..............
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post #92 of 190 Old 12-18-2011, 06:29 PM
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Quote:
Originally Posted by DanFrancis View Post

Amir, "drinking the Kool-aid" means you are a believer. I was NOT implying that you are biased; I am saying you are biased outright. It is NOT a bad thing, I'd rather you were biased because you believe in something than because it makes you a buck.

That was precisely WHY I said it is a good Kool-Aid to drink. All Synthesis procedures and technologies are grounded in research.

My comments implied absolutely no impropriety.

Dan

Dan, as commentary goes in that regard, I say you put in the best way possible . Much appreciated.

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post #93 of 190 Old 12-18-2011, 06:56 PM - Thread Starter
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Quote:
Originally Posted by DanFrancis View Post

Yeah, but who could pass-up another Steve-Jeff face-off?

These things are classic; it's like an old episode of the "Odd Couple"!

I mean, who better to get a thread shut-down than Steve and Jeff??

Dan

OK Dan, here goes...

We started the 'Odd Couple' ~5 years ago when the Theta was a state of the art piece (in the minds of its owners) even without HDMI. A big prounouncement when all other high end SSPs included HDMI and digital post processing of lossless soundtracks. The 6shooter equalled HDMI performance of other, newer SSPs (again, in the minds of its owners) though the connected Blu Ray player does the D/A conversion and more (*note using the 6shooter completely bypasses all Theta circuitry - making it a $16K remote control). So, the Theta superiority story was exposed.

Five years later, it finally has HDMI but its Extreme DACs are circa 1999, vintage Motorola. Speaking of D/As, many Theta owners feel owning a CBIII negates the need for room correction. They fear that an extra A/D step destroys the sound... the Theta lie resumes (e.g. an untamed room is more desirable if you can run the SSP on its own without sonic modification - e.g. Room correction / EQ). Further, that somehow the lack of an extra A/D step is more preferable than correcting phase, reverb time, frequency response, etc. is beyond me.

Is there a Theta owner using room correction????

Some of us saw the need for DSPs, controlling of reverb time, freq response many years ago. It's good to see others have finally caught on.

OK Dan, that manifesto was for you!

How's that???

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There are more than a handful of [op amps] that sound so good that most designers want to be using them as opposed to discreet transistors. Dave Reich, Theta 2009
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post #94 of 190 Old 12-18-2011, 06:57 PM - Thread Starter
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Quote:
Originally Posted by jbm007 View Post

Jeff

If you show up for the demo in January I would suggest you bring a bib with you...............

Because you will be dribbling all over your self while your here.

Dan has put hours into this show down, and to hear it; is to make normal men dribble and weep.
We did a demo over the weekend for someone and it was sad. The poor SOB couldn't decide what would hurt more; the 60K his wife would make him spend for a Kaliedescape system or the 60K it was going to cost him to upgrade his existing audio setup. Just sad ..............

My only question on attending is whether to fly or drive.

My Home Theater of the Month- Le Petit Trianon

There are more than a handful of [op amps] that sound so good that most designers want to be using them as opposed to discreet transistors. Dave Reich, Theta 2009
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post #95 of 190 Old 12-18-2011, 07:51 PM
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Quote:
Originally Posted by Raul GS View Post

...I'm not Dan, but neither of those answers makes much sense. Unlike main speakers, subs can be very well evaluated by metrics; i.e. there really 1. should not be a need to test them to see if the suit your home. Conversely, 2. driver size and frequency response by themselves provide very little information.

Raul, thanks for your input.

1. By not testing, did you mean that it's not important to test-listen to the subwoofer to see how it sounds in your system prior to buying?
From Dan's/Amir's/et al's discussion so far, it seems room EQ improves upon your initial system, but it doesn't make all systems sound alike. In that sense, shouldn't how a subwoofer sound matter?
Dan spoke about the subjective "sounds" of subwoofer - tight/defined/one note, etc. - implying, to me anyway, that it is *still* important to listen to it first before buying, no?

2. Frequency response of the subwoofer reflects how deep it's extending - I would have thought it is among the most important parameter to consider?
Driver size *seems* to have some importance in Dan's recommendation, what his clients use, etc. Perhaps this affect the subjective "sound" of the subwoofer? In other words, say a 12 inch driver SW sounds different from an 18 inch driver SW, then it should matter, no?

3. What "metrics" were you referring to please - something else besides output at certain frequency? TIA

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Originally Posted by DanFrancis View Post

Alumapro Alchemy MX 12" , mass loaded cone, in a 2 ft^3 sealed- box. Works great, quits around 22hz. Does a great job of smoothing bass, stays tight and defined all the way and plays nice on 300W.
.....
Me, I personally don't really care for JL woofers- they have great output an all, but it has always sounded like one-note bass to me.
Dan


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post #96 of 190 Old 12-18-2011, 09:09 PM
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Quote:
Originally Posted by thebland View Post

3. TODAY... Professionally designed room, moderately priced SSP and room correction to be the best.

If you're going to resample the SSP output, distort it, and convert to analog using the relatively inexpensive DACs in the EQ... do you really even need a mid range SSP as the frontend?

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Originally Posted by thebland View Post

They fear that an extra A/D step destroys the sound...

I would like the experts opinion on the extra A/D/A steps involved with "bolt on" room correction. I understand there's a potential net gain with EQ, but all else being equal, wouldn't a digital connection be better?

Putting room correction in the SSP makes much more sense to me. That's the highend SSP I'm waiting to buy.

 

 

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post #97 of 190 Old 12-18-2011, 09:26 PM
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Hi Can (from a fellow 6speeder),

I would say that the choice of subs should be made using a combination of price, appearance, and performance. The price is what it is, the appearance (size and fit'n'finish) matters depending on the room the subs will go in, and the performance can be determined by reviews, and basic stats. If you have the space, something like 2 or more SVS ultra 13s will rock your world. I chose 4 JL F113s b/c the subs are out in the open, I love how they look, they have plenty of output, and they are relatively compact.

Incidentally, I find it hard to believe that Dan has heard them set up properly if he thinks that they are boomy and one-note subs. I don't know of another sub that is as universally praised in the press and user forums like the JL products. I've successfully blended the front pair of subs with my ATC speakers (with the help of Adam Pelz) and they are incredibly "musical" subs.

I've done extensive measurements comparing the seat-to-seat variation of 1 sub, 2 subs, 3 subs, and 4 subs. The best bang for the buck is definitely 2 subs b/c there is such an improvement going from 1 to 2. It's like horsepower, more is better!

Quote:
Originally Posted by cannga View Post

Raul, thanks for your input.

1. By not testing, did you mean that it's not important to test-listen to the subwoofer to see how it sounds in your system prior to buying?
From Dan's/Amir's/et al's discussion so far, it seems room EQ improves upon your initial system, but it doesn't make all systems sound alike. In that sense, shouldn't how a subwoofer sound matter?
Dan spoke about the subjective "sounds" of subwoofer - tight/defined/one note, etc. - implying, to me anyway, that it is *still* important to listen to it first before buying, no?

2. Frequency response of the subwoofer reflects how deep it's extending - I would have thought it is among the most important parameter to consider?
Driver size *seems* to have some importance in Dan's recommendation, what his clients use, etc. Perhaps this affect the subjective "sound" of the subwoofer? In other words, say a 12 inch driver SW sounds different from an 18 inch driver SW, then it should matter, no?

3. What "metrics" were you referring to please - something else besides output at certain frequency? TIA


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post #98 of 190 Old 12-18-2011, 09:56 PM
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Quote:
Originally Posted by rabident View Post

If you're going to resample the SSP output, distort it, and convert to analog using the relatively inexpensive DACs in the EQ... do you really even need a mid range SSP as the frontend?



I would like the experts opinion on the extra A/D/A steps involved with "bolt on" room correction. I understand there's a potential net gain with EQ, but all else being equal, wouldn't a digital connection be better?

Putting room correction in the SSP makes much more sense to me. That's the highend SSP I'm waiting to buy.

R U on the MP 20 list yet?

Thank you very much

Fury
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post #99 of 190 Old 12-18-2011, 10:06 PM
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Quote:
Originally Posted by Kishore View Post

Let me state that using over 3 subs+LFE Sub, and optimally placing them will enable me to achieve my objective of low-end+minimized low-freq variance, without investing additional $15K in a new box.

OK, but that's different than your earlier claim that it will "achieve 'most' of SFM in low frequency range".

Every attempt at subwoofer correction that I've seen, automated or manual, is based on improving frequency response. I have yet to see another system (or method, like Geddes) that applies 100% of its resources to maximizing seat to seat consistency, with absolutely zero regard to any improvement in frequency response. Even the Welti paper you linked to about subwoofer placement makes no mention of getting smoother, flatter response; only greater consistency. Apparently he felt that placement alone didn't give the consistency he wanted, hence him coming up with SFM as the next step.
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Kapeesh?

Capicé.

Sanjay
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post #100 of 190 Old 12-18-2011, 11:34 PM
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My experience with JL has been their own booth demo rooms at CEDIA (Denver), and listening to the Gothams in obgyn's system when I was in CA working at CAT. All sounded the same to me, and I didn't care for the sound. JL doesn't make a bad product- just not my cup of tea. And I don't think they're boomy, just somewhat underwhelming. I've never really cared for woofers with tons of travel, I'd rather have something that maxed at 1" or less, and just use more of them.

Seaton builds a really nice product for the buck, even if I can't sell them, Mark's a buddy and I'll support however I can (doesn't hurt that he really does build a pretty badass sub).

I've said it before; I'm really starting to view all of this stuff as various tools to get the job done- no more awe, or pomp and circumstance. What makes MY experience better? I've seen better stuff than most, I'm pretty difficult to impress, so if you can manage to raise my eyebrows (or make me giddy like a school-girl....) then you've done something pretty 'F'in cool! I've had that giddy feeling three times lately:

Once, when I finished the TEQ process and finally got the bass where I liked it.
Once, when we finally had the Kaleidescape up and running.
Once, when I finally heard the Datasat sing in my room.

I understand the raves behind these devices, and that initial experience of "so THIS is what all the fuss is about!" is fun since I don't get that too much anymore.

Dan

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post #101 of 190 Old 12-18-2011, 11:50 PM
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Quote:
Originally Posted by Raul GS View Post

There is no doubt that SFM provides an advantage, the question is whether it is night and day. In some circumstances it may matter, but in others the differences may be small to insignificant when considering other factors.

Don't know about "insignificant", but I agree that the amount of improvement will vary; though the same can be said about room correction in general. And, as with room correction, the set-ups that benefit the most are usually the ones where where optimal placement is not possible, which happens more often than not.
Quote:
Originally Posted by Raul GS View Post

At another forum when one of the people implementing the system (I can't remember if it was CEDIA) posted his results before and after. The after results were very good, but so were the before, even though they made no attempt to place the subs in ideal positions.

That was probably the post at SMR Forums, which showed how placement and Sound Field Management improved consistency in the Harman set-up at CEDIA. But even using excellent placement (4 subs in 4 corners), they were only able to get consistency to around 4dB (not 2dB, like you said).



SFM was able to bring variance down to 2.36dB at its worst point (almost 50% improvement). Far more important, it got the responses of the front row and back row (4 black traces and 4 red traces, respectively) to practically sit on top of each other. Placement alone wasn't able to close that gap.



Keep in mind that the above graph is prior to any room correction being applied, just subwoofer optimization.

Sanjay
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post #102 of 190 Old 12-19-2011, 12:42 AM
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I know that Audyssey is not something those in this forum are likely to utilize, however it is what I have (Audyssey Pro actually). I quite like it, although I know there is much debate on benefits of EQ. I wanted to mention one aspect that I think is especially valuable and that is dynamic EQ. It basically raises the volume of the subs and surrounds to compensate for human hearing (low frequencies and sounds rom the side and rear being perceived as quieter) in a way that takes into account the master volume level and the loudness of the content (in real time). I couldn't watch movies without Dynamic EQ anymore.

I wonder if these technologies being discussed have a similar tech?
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post #103 of 190 Old 12-19-2011, 02:00 AM
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Originally Posted by gamelover360 View Post

I wonder if these technologies being discussed have a similar tech?

I don't think the room correction technologies being discussed (Dirac, Trinnov, ARCOS) have their own brand of loudness compensation, like Audyssey does, but those pre-pro manufacturers (DataSat, ADA, Lexicon) can license similar tech, such as THX Loudness Plus and Dolby Volume. The latter includes loudness compensation (similar to Audyssey Dynamic EQ) as well as a volume leveler (similar to Audyssey Dynamic Volume), but avoids the over-boosted surround problem that Audyssey has.

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post #104 of 190 Old 12-19-2011, 02:27 AM
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Quote:
Originally Posted by sdurani View Post

I don't think the room correction technologies being discussed (Dirac, Trinnov, ARCOS) have their own brand of loudness compensation, like Audyssey does, but those pre-pro manufacturers (DataSat, ADA, Lexicon) can license similar tech, such as THX Loudness Plus and Dolby Volume. The latter includes loudness compensation (similar to Audyssey Dynamic EQ) as well as a volume leveler (similar to Audyssey Dynamic Volume), but avoids the over-boosted surround problem that Audyssey has.

I don't know about a specific over boosted surround problem, other than certain content that doesn't adhere to a standard being mixed too hot (games, tv, music...basically everything but movies). Dynamic EQ's aggressiveness can be adjusted a variety of ways via reference level offset and also intellivolume.

Also, loudness plus is different in one major way....it doesn't dynamically adjust to the loudness of the actual content....it only works off the master volume. Not saying dynamic eq is better, just pointing out an important distinction.
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post #105 of 190 Old 12-19-2011, 09:19 AM
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Quote:
Originally Posted by sdurani View Post

Don't know about "insignificant", but I agree that the amount of improvement will vary; though the same can be said about room correction in general. And, as with room correction, the set-ups that benefit the most are usually the ones where where optimal placement is not possible, which happens more often than not. That was probably the post at SMR Forums, which showed how placement and Sound Field Management improved consistency in the Harman set-up at CEDIA. But even using excellent placement (4 subs in 4 corners), they were only able to get consistency to around 4dB (not 2dB, like you said).



SFM was able to bring variance down to 2.36dB at its worst point (almost 50% improvement). Far more important, it got the responses of the front row and back row (4 black traces and 4 red traces, respectively) to practically sit on top of each other. Placement alone wasn't able to close that gap.



Keep in mind that the above graph is prior to any room correction being applied, just subwoofer optimization.

Interesting. I have 4 subs and there is still a bit of variation in measured response at different seat locations. I'll have to read more about SFM.

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post #106 of 190 Old 12-19-2011, 09:43 AM
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Quote:
Originally Posted by gamelover360 View Post

I don't know about a specific over boosted surround problem

If you lower the volume enough, you can get the surrounds to overpower the fronts. That should never happen with any loudness compensation technology. This is the reason Audyssey came up with a level offset, to trick DEQ into thinking that reference level is lower than it actually is.

We all know that low frequencies get quiter sooner than the midrange as the volume is lowered. But DEQ starts from the mistaken premise that sounds around you get quieter sooner than sounds in front of you. I have yet to see any psychoacoustic research to support that notion.

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post #107 of 190 Old 12-19-2011, 10:16 AM
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Originally Posted by amirm View Post

For your part, you own a competing processor

I resemble that remark
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and forever are in this defensive mode of feeling bad when another system is being discussed.

Actually, I have often spoken in complementary terms about your fab processor (and in this thread corrected thebland when he excluded it)
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I don't understand why you are so insecure about this.

Actually, I could argue that the above comment is projection in your part since it is you who always comes back to JBL no matter what systems are being discussed in eqs, and you made some questionable implied statements about another product when you knew you lacked insufficient exposure. But I won't make that argument...I understand it's your MS background tryting to take over the world
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You argue against SFM when there is really nothing but goodness there.

Again, though doth protest too much. I have not argued SFM it is not a good tool because it is. I have argued that it is not the sole solution, and under many circumstances (e.g. the example of JBL's own setup) the effects are small. Please note that the difference between with and without SFM was lower than I stated, it is only 1.6 db. That is in a case where they did not even attempt to setup the subs properly. I'm pretty sure that with the aid of a DSP, and a little sweat equity one can easily improve on the non SFM system by at least 1 db. 1.6 db variation difference is not that much of an issue, .6 db is meaningless. That being said, I do think SFM is a great tool, just not the only tool.

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post #108 of 190 Old 12-19-2011, 10:21 AM
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Quote:
Originally Posted by sdurani View Post

If you lower the volume enough, you can get the surrounds to overpower the fronts. That should never happen with any loudness compensation technology. This is the reason Audyssey came up with a level offset, to trick DEQ into thinking that reference level is lower than it actually is.

We all know that low frequencies get quiter sooner than the midrange as the volume is lowered. But DEQ starts from the mistaken premise that sounds around you get quieter sooner than sounds in front of you. I have yet to see any psychoacoustic research to support that notion.

This might make a good research project for one of Tom Holman's graduate students.
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post #109 of 190 Old 12-19-2011, 10:27 AM
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Quote:
Originally Posted by sdurani View Post

That was probably the post at SMR Forums, which showed how placement and Sound Field Management improved consistency in the Harman set-up at CEDIA.

Yes, that is the one, thanks.

Quote:


But even using excellent placement (4 subs in 4 corners),

Actually, we don't know how excellent it was since we have no comparative data, but considering the differences, it was pretty good.
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they were only able to get consistency to around 4dB (not 2dB, like you said)

Actually, the differences between SFM and non-SFM was closer than I stated (but I do recognize the way I stated may have led to some misunderstanding)
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SFM was able to bring variance down to 2.36dB at its worst point (almost 50% improvement).

That is only 1.6 dB better. Not a big difference, especially if you consider that the subs were not carefully placed. It would not be difficult to argue that one could improve on a non-SFM with DSP by at least 1 dB. That would make the difference only .5 dB, insignificant by most auditory measures.

Don't get me wrong, I do consider SFM a valuable tool for many, I just don't think it is the change maker (i.e. no other options) you and Amir sometimes suggest.

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post #110 of 190 Old 12-19-2011, 10:31 AM
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Originally Posted by The Bogg View Post

Interesting. I have 4 subs and there is still a bit of variation in measured response at different seat locations. I'll have to read more about SFM.

SFM is a very good tool to address that problem. Neither Dirac nor Trinnov have an equivalent automated tool. You should see if Amir can provide you with a sample unit to experiment.


Did I just suggest someone try SFM




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post #111 of 190 Old 12-19-2011, 10:50 AM
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Quote:
Originally Posted by thebland View Post


OK Dan, here goes...

We started the 'Odd Couple' ~5 years ago when the Theta was a state of the art piece (in the minds of its owners) even without HDMI. A big prounouncement when all other high end SSPs included HDMI and digital post processing of lossless soundtracks. The 6shooter equalled HDMI performance of other, newer SSPs (again, in the minds of its owners) though the connected Blu Ray player does the D/A conversion and more (*note using the 6shooter completely bypasses all Theta circuitry - making it a $16K remote control). So, the Theta superiority story was exposed.

Five years later, it finally has HDMI but its Extreme DACs are circa 1999, vintage Motorola. Speaking of D/As, many Theta owners feel owning a CBIII negates the need for room correction. They fear that an extra A/D step destroys the sound... the Theta lie resumes (e.g. an untamed room is more desirable if you can run the SSP on its own without sonic modification - e.g. Room correction / EQ). Further, that somehow the lack of an extra A/D step is more preferable than correcting phase, reverb time, frequency response, etc. is beyond me.

Is there a Theta owner using room correction????

Some of us saw the need for DSPs, controlling of reverb time, freq response many years ago. It's good to see others have finally caught on.

OK Dan, that manifesto was for you!

How's that???

Irrelevant now. Dirac Live all done digitally next year and you are the one looking at an external solution. I don't think many have been in a purpose built room with nearly perfect ratios like Steve has. He also uses multiple subs with EQ. Also has the luxury of being able to move both speakers and seats. Right at the starting line he has a huge advantage.

Never become so involved with something that it blinds you.
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post #112 of 190 Old 12-19-2011, 11:16 AM
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Originally Posted by Raul GS View Post

Actually, I could argue that the above comment is projection in your part since it is you who always comes back to JBL no matter what systems are being discussed in eqs, and you made some questionable implied statements about another product when you knew you lacked insufficient exposure.

Raul, this has been one of our (AVS) most constructive threads on this topic. Despite the fact that we are talking about competing solutions, no food fight had occurred. You are on a path to turn this into a battle of which is right. The title of the thread doesn't ask that. It is debating the entire notion of Room EQ as an essential component. We are all chiming in from our vantage point of view. Dan is not discussing JBL and I am not discussing Trinnov/Dirac. That is fine. It is not like we are expected to carry and be experts at all the solutions of that type. These are specialized products and it pays to know them well and come with deep experience in them than shallow across many.

Read my first post. Does it jump to advocate room EQ? Nope. I said and was clear that it should be step #3 in your attempt to improve your theater sound. The first I emphasized is proper number and placement of subs. That actually turned the tone of the thread negative toward room EQ. It is that type of discussion that is asked about and desirable. Not a food fight that you want to turn it into as to which is "THE" product. None of us have said which is "THE" product to use. You are trying to position me as saying that and that is turning this thread into a food fight. I wish you would not do that. If you have something to share regarding the benefits or lack thereof of these products instead, please put that forward instead.

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Again, though doth protest too much. I have not argued SFM it is not a good tool because it is.

That period then should have been it. People are asking if there is a benefit to these solutions or not. If something has a benefit, and only comes as part of a room EQ package, then they need to know about it.

Quote:


I have argued that it is not the sole solution, and under many circumstances (e.g. the example of JBL's own setup) the effects are small.

You lack sufficient data to make that statement. You may be right but you have presented no data or explanation to indicate so. As such then, it looks like you are being non-constructive, throwing rocks for sake of doing so.

Quote:


Please note that the difference between with and without SFM was lower than I stated, it is only 1.6 db. That is in a case where they did not even attempt to setup the subs properly.

Raul, please spend five minutes researching the topic before throwing out statements that can easily be show to be well, "utter nonsense" to use your words . You have been in this argument before. You should know the facts.

Here is the text that goes with the original text:

"These are from our actual room at CEDIA, and show the effects of multiple subs over multiple rows, and also how Sound Feild Management, both in the existing JBL Synthesis SDEC4500 and in the not yet released Lexicon MP20 will work.

I am now going to do something that no other company probably can or will do, and be totally transparent and who you EXACTLY how the room was effected and improved.

ALL BELOW PICTURES ARE AT 1/12 OCTAVE RESOLUTION AND HAVE NO ROOM EQ APPLIED. THIS IS ALL JUST SUBWOOFER OPTIMIZATION."


PICTURE 1: ONLY ONE SUBWOOFER
This is typical, for the 8 locations (seats) they are very different. 67 hz has almost +/- 6 db of variation.



The above is what you get if you didn't use multiple subs and optimal placement.

PICTURE 2: 4 SUBWOOFER WITHOUT ANY DSP
This is what we published in AES 8 years ago and why we do multiple subs. You can see how much better the room is already, and now the worst place is at 52 hz with almost 4db of standard variation.



Above then is what you get with multiple subs and *optimal* placement (although not based on CFD). Your notion that they did not choose the optimal position for the sub where they wrote the book literally on the topic, is fallacious.

PICTURE 3: 4 SUBWOOFER WITH SOUND FEILD MANAGEMENT
The worst spot at 52 hz is now under +/-2.5. Which means that it is almost 50% better. And that the biggest swing from best to worst has been reduced by 3db, which is a large amount. Plus the rows are much closer below that point.



Finally, we see that SFM fine tuned the performance further. The order though is what I proposed: start with multiple subs and get that right. What SFM will then do is to account for smaller differences that you may not have taken into account such as reflectivity of all the materials, differences between real and theoretical subs, the difference between different models of subs, etc. Combined, the system above went from +- 6 db of variation to +- 2.5 db. That is a huge reduction before doing any EQ!
Quote:


I'm pretty sure that with the aid of a DSP, and a little sweat equity one can easily improve on the non SFM system by at least 1 db.

So you are claiming that you could manually get the above system to have +-1.5 db variations? Do you have data you can point us to with rooms that have that kind of response? Do you have measurements of your room achieving that? You say you are sure of that so I hope we see and learn how that is done in your next post.

Quote:


1.6 db variation difference is not that much of an issue, .6 db is meaningless.

Look at the dotted line at the bottom of the graph. That plots the variations relative to frequency. Compare the first to last. It is a remarkable improvement based on SFM and proper sub placement. Every technique helps to get us to where we want to be: flat response. The less you ask the EQ to do, the better off you are.

Quote:


That being said, I do think SFM is a great tool, just not the only tool.

SFM is the only automated tool of its type. It is patented so you are not going to see someone else with it. So you are wrong; it is the only tool of its type. The only work-around I know is to use Keith's CFD simulation (tier 2 model) where he tells you the levels and phase for the sub in addition to actual placement of subs. Outside of that, you can play from here 'till end of the world and you may not better the results of SFM above. But if you have some proof that you can match it, other than wishful claims, I am all ears .

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post #113 of 190 Old 12-19-2011, 11:25 AM - Thread Starter
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Amir,

You have clearly won the argument... (How come you keep pounding Raul with logic and objective data??

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post #114 of 190 Old 12-19-2011, 11:28 AM - Thread Starter
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Quote:
Originally Posted by Bulldogger View Post

Irrelevant now. Dirac Live all done digitally next year and you are the one looking at an external solution. I don't think many have been in a purpose built room with nearly perfect ratios like Steve has. He also uses multiple subs with EQ. Also has the luxury of being able to move both speakers and seats. Right at the starting line he has a huge advantage.

Internally would be ideal and cheaper... but will it be able to do 3-4 subs, all features, come in under $10K?

Hopefully, it is not more than a year.

If so, then you will be in a good place.

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There are more than a handful of [op amps] that sound so good that most designers want to be using them as opposed to discreet transistors. Dave Reich, Theta 2009
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post #115 of 190 Old 12-19-2011, 11:39 AM
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Maybe we should define a "home theater." as the OP listed in the thread title. Jeff later posted something about only being concerned with his seating location, which he later, shall we say expanded to, for the sake of completeness, include other seating locations. It has been said that Fury shares the same egocentric, egomaniacal, narcissistic and gluttonous sonic disposition, at least. So then, more than likely, several "home theaters" have either limnited seating-grant you not that many on this forum- and/or the owner is only interested in perfecting a very small seating zone-say one seat. That is a subset then that, as I read this and the thread Fury recently started, which met an ignominious end, would benefit less than a multi-seat "home theater."

The next step, would be to have you experts create an algorithm, maybe Dr. Dan could do that, if it would give him joy, and expand on Amirm and Dan's already listed hierarchy of audio enhancements. A retro fit "home theater" can have all sorts of mode issues, based on dimensions, for example, and despite qualifying for the over $20K category, maybe several times over, isn't going to have those addressed by any deconstruction process. Where is that, I suspect< fairly common owner then in the flow chart?

Fury apologizes for this stream of poor synaptic consciousness, but he felt pressure to post what had been a bother for a while now.

Thank you very much

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post #116 of 190 Old 12-19-2011, 11:40 AM
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All processing is done digitally anyway- the extra a/d d/a steps are less invasive than what's being dealt with (distortions in signal from the room/speaker interaction in magnitude/phase/time domains). Even if a Theta owner added Carl's upcoming Dirac box to their Casa, it would be an improvement. BTW- Datasat owners will be able to take advantage of both Dirac and Trinnov in the digital domain, if they see fit- AES output to a commercial Trinnov processor...that is some stellar stuff!


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post #117 of 190 Old 12-19-2011, 11:56 AM - Thread Starter
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Quote:
Originally Posted by DanFrancis View Post

All processing is done digitally anyway- the extra a/d d/a steps are less invasive than what's being dealt with (distortions in signal from the room/speaker interaction in magnitude/phase/time domains). Even if a Theta owner added Carl's upcoming Dirac box to their Casa, it would be an improvement. BTW- Datasat owners will be able to take advantage of both Dirac and Trinnov in the digital domain, if they see fit- AES output to a commercial Trinnov processor...that is some stellar stuff!


Dan

I agree with you Dan. I have never found the extra A/D/A steps in my own system to cause any audible degradation - but the benefits of control of reverb time, freq response, etc to be far and away beneficial over nothing at all. I'm sure A/D/A anomalies can be plotted on an objective data sheet but I do not think, with well designed DSPs, that the changes meet the threshold of human hearing so as for real whorl impact would be more academic than anything else.

With what we know... I am still surprised that so few here embrace it. It's such an easy thing to add with the right installer. The benefits are so high... I just don't get it??

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There are more than a handful of [op amps] that sound so good that most designers want to be using them as opposed to discreet transistors. Dave Reich, Theta 2009
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post #118 of 190 Old 12-19-2011, 11:59 AM
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Under the old JBL Synthesis® DACS system, here's a before and after for the graph-conscious among us. This is with two JBL S1S-EX subs (18" 2242-H driver). The subs optimally are placed in the front center and rear center walls of a well treated, small 15.5x17.5x8.67' room with a passive bass dump in the left rear corner. This older DACS system required two laptops, a DACS processor, an Ethernet router, five mics, and multiple screens! I can only imagine how much nicer ARCOS is.

First screen shot is in-room bass response without SFM (no smoothing).
Second screen shot is SFM and EQ applied (delays, trims, and phase on another screen).
Third screen shot is in-room response with SFM (no smoothing).
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post #119 of 190 Old 12-19-2011, 12:30 PM
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Quote:
Originally Posted by amirm View Post

None of us have said which is "THE" product to use.

I apologize, that is the impression I get from your post, but it is somewhat understandable when you make statements such as
Quote:


The only work-around I know is to use Keith's CFD simulation (tier 2 model) where he tells you the levels and phase for the sub in addition to actual placement of subs. Outside of that, you can play from here 'till end of the world and you may not better the results of SFM above.

I agree, you did not state SFM is the only solution, but you strongly imply that other than using another product you sell, there is no other way to come close to SFM (even though JBL's own data would suggest otherwise, even without the aid of DSP; i.e. getting close).
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You lack sufficient data to make that statement.

Regarding data, are you suggesting it was unfair for me to reference JBL's own data? As I said JBS's own data for their demo for 4 subs between non-SFM and SFM when just placing subs in no measured fashion was 1.6 dB, that is not a large discrepancy. Are you willing to argue that an individual through the use of DSP would not be able to improve on sub performance without SFM by at least 1 dB as compared to no "calibration" (and better sub placement) whatsoever? If they can, the difference under these circumstances is only .6 dB, virtually meaningless.
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So you are claiming that you could manually get the above system to have +-1.5 db variations?

Sorry, but that is a misrepresentation of what I stated (or I think I stated ). I wrote that an individual with the use of a tool such as a DSP could be expected to be able to improve on a non-SFM system by at least 1 dB. In that case, the difference between SFM and DSP would be .6 dB, not very meaningful.
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You have been in this argument before. You should know the facts.

Yes, and the only manner in which I misstated the facts was to the benefit of SFM; i.e. the differences between 4 subs and non SFM and with SFM were slightly smaller (I said it was .4 higher, which would serve to benefit SFM's position).
Quote:


Combined, the system above went from +- 6 db of variation to +- 2.5 db. That is a huge reduction before doing any EQ!
Do you have data you can point us to with rooms that have that kind of response? Do you have measurements of your room achieving that?

Again, in JBL's own demo, the difference between 4 randomly placed subs with SFM and without SFM was 1.6 dBs. Not a large discrepancy. An improvement? Yes, but 1.6 dBs between seats from an auditory perspective is not large, especially since one accounts for the fact that the 4 subs sans SFM could also be improved though DSP.
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Every technique helps to get us to where we want to be: flat response. The less you ask the EQ to do, the better off you are.

Totally agree, and also agree that KY tool can also be a wonderful help.
Quote:


SFM is the only automated tool of its type

In case I have not been clear enough (sometimes I think "clarity" requires that I bow to SFM ) I agree with you and Sanjay, SFM is the only automated tool for that purpose and it is a useful tool. However (please note this caveat does not in any way invalidate the previous statement) SFM is not the only tool through which acceptable results can be achieved (which you sometimes recognize by implication despite the other statements to the contrary).

Thebland, I realize that using JBL's own data may not be considered objective data by some , but I thought it was reasonable in this case. Furthermore, I acknowledge that trying to use their data and actual numbers in the course of trying to make a logical argument may be seen by some as illogical , I apologize, I shall refrain from further comment on this matter. I hope you are not feeling to down because you were not able to catch too many Theta fish.

Ignorance more frequently begets confidence, than it does knowledge. Charles Darwin
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post #120 of 190 Old 12-19-2011, 12:31 PM
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Yes.

Kaboom.
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