6.5" woofers just can't rock - Page 7 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #181 of 404 Old 10-22-2007, 05:33 PM
AVS Special Member
 
psgcdn's Avatar
 
Join Date: Sep 2006
Location: Prov. of Quebec, Canada
Posts: 4,459
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 39 Post(s)
Liked: 199
Quote:
Originally Posted by LTD02 View Post

those things definitely ROCK. there have been other PA speaker suggestions as well. i'm thinking somewhere in between has to be some middle ground.

Haven't read the whole thread, but Klipschorns are very sensitive, dynamic, live and natural (mid-bass is not bloated), and you can get them for 2K$ in the used market.

Remember, it's called "AV Science"!

My HT
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Peter

psgcdn is online now  
Sponsored Links
Advertisement
 
post #182 of 404 Old 10-22-2007, 09:55 PM
Advanced Member
 
Vinculum's Avatar
 
Join Date: Dec 2001
Location: York, Pa
Posts: 943
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 12
Quote:
Originally Posted by LTD02 View Post

Dr. V, Great stuff. What tipped you over to the Mackie Monitors?



What spec picks this up? Is it something like noise floor? I don't know.

The horn is like a megaphone, any little noise is magnified when it comes out the other end. I would say the hiss is due mostly to the amplifier noise floor. Live sound loudspeakers don't care about low volume hiss. They are going to rock the house with large crowds. Perhaps Klipsch's home speakers try to minimize this effect.

A friend of mine who owns a recording studio suggested I try out the Mackies or Event monitors. The Events were a little cheaper. He preferred the Mackies. His studio uses Adam monitors, they cost more than the Mackies.

As i said before, look at all the advantages you have with active studio monitors. No looking for the perfect amplifier - it is already done for you. The amplifiers are tuned for each individual driver. If you have ever seen the inside of one, you'll see many potentiometers for damping, level matching, ect. These are set from the factory and should not be touched. No worries about power robbing fat lossy speaker wire with high capacitance, back EMF, VSWR problems, ect. The "speaker wires" are less than 6" long inside the monitor. Crossovers are active, meaning no phase shift anomalies due to capacitance and inductance of a passive crossover. Biamped naturally, EQed flat out of the box in the nearfield, active limiting & thermal circuits - don't worry about bottoming drivers, because when the limit light comes on you just back them down a little bit. Balanced inputs for low noise on long runs. Balanced connections use common mode rejection techniques to lower noise and the fact you aren't attempting to transfer power from an amplifier halfway across the room to a driver. XLR cables are CHEAP compared to jumper cables needed for passive speakers. Plenty of room contour controls on the back panel. Semi-servo design for the low frequency transducer. Oh and they are THX pm3 certified. I guess i could drone on and on about the benefits of active studio monitors as I have in the past on this forum. Most people have their minds made up before they even buy anything and these facts just fall on deaf ears most of the time. I know I was sold after hearing them! (even tho i bought them before hearing them - I trusted a recording engineer, someone who's income depends on listening and probably should have a better ear than most people)

All these things make for an extremely accurate speaker, which is what I wanted. Now if you value entertainment (SPL?) over accuracy, then you might look into something else. But I might add the Mackies are rated at 120dB per pair. If you offload some bass onto some subwoofers, you can get a little more SPL and headroom out of them. I think a PAIR of HRS120's under EACH monitor would just knock you out of your shoes, but I haven't heard them configured as such. Everyones preference and environment differs of course. In my office I have a pair of HR624's on my PC. They sound so good by themselves in a small room, and I keep cranking up the volume. I have never seen the limit light come on. They get uncomfortably loud before they stress out. As far as accuracy goes, I'm sure my office setup is better for critical listening. The room isn't influencing the sound very much because of the size and distance to the monitors. Larger rooms need more work. Lots of work to sound as good. Room treatments are an art by themselves. Check out a book called "The Master Handbook of Acoustics". Everyone should have a copy.

Hey Syswei, Thanks for the link! Good read. I was impressed by the mic technique for the servo. I wish I could hear some of those bad boys!

I've babbled on enough for now, I need to get away from the computer for a few hours and do something around the house!

Dr V


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Vinculum is offline  
post #183 of 404 Old 10-23-2007, 04:52 AM
Advanced Member
 
mpenton's Avatar
 
Join Date: Feb 2002
Posts: 533
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Perhaps you might find the answer in some older speakers http://www.oaktreeent.com/Stereo_Speakers.htm

Most of these vintage (old) speakers sported 10-12" bass drivers that made you feel the music. I owned a pair of Sansui's w/12" bass drivers and aside from causing the lights to dim when the freq. dipped down and the volume was up they were the last speakers I owned that would move furniture. Of course if you tired to put 5 of them in a normal sized room you didn't have much space left ;-)
mpenton is offline  
post #184 of 404 Old 10-23-2007, 05:40 AM
AVS Special Member
 
syswei's Avatar
 
Join Date: May 2005
Location: CT
Posts: 1,100
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I wanted to look more into the dome vs horn issue (since right now I'm considering a dome tweeter speaker).

Genelec http://www.genelecusa.com/products/ is a maker of pricey (but not as pricey as Meyer) active monitors, and has a broad product line. What I found is that even Genelec pro monitor systems with a single-15" bass driver or dual-12" bass drivers are offered only with a 1" metal dome tweeter. It is only when you move up to a speaker that has dual-15" drivers that there are two versions....1 with a dome, 1 with a horn. At the level of dual-18" drivers, they offer only a horn tweeter.

To me this suggests that (1) horns have some downsides at less-than LOUD volumes (maybe they're noisy, maybe they have more distortion?), and (2) a dome probably offers enough volume for me (as I am currently considering a speaker with dual-8" woofers).
syswei is offline  
post #185 of 404 Old 10-23-2007, 05:53 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 248 Post(s)
Liked: 96
Quote:
Originally Posted by Drew Eckhardt View Post

This is inaccurate on the reference level definition and output power requirements (and the website author can't do arithmetic).



Dolby reference level defines a dialog level of 74dB SPL. You only get 85dB SPL when feeding -20dBFS test signals into the system. Peak levels vary with the dynamic range decided upon when the disc was mastered. While the maximum is 31dB allowing for 105/115dB peaks, the default encoder settings and most disks only allow for 27dB of dynamic range. That cuts your power requirements by 2.5 for the typical sound track.



You forgot that THX receivers calibrate 0 dB on the master volume to be compatible with DD DVD's that use the default Dialnorm value of -27. THX receivers boost DD by 4 dB to do this. DTS is treated in the normal way because Dialnorm is not used with DTS.

The end result is a DD (DN -27) or DTS DVD can still have peak levels near the 105/115dB level if you have a THX receiver's calibrated master volume set to 0 dB.

A DD DVD with a Dialnorm value of -31 (AKA no dialnorm like Lord of the Rings)) can peak at the 109/119 dB level if you have a THX receiver's master volume set to 0 dB.


A non-THX receiver plays back DD material 4 dB lower in volume that a THX receiver because they base their master volume levels on the Dialnorm value of -31 (AKA no Dialnorm). Typically, a DTS DVD will playback at 4 dB louder in level than a standard DD DVD (AKA default dialnorm value of -27) on a non THX receiver.



Anyhow, most everyone sets the volume control lower than the "reference level" setting, so system power requirements are often way overspecified for real world use in the typical home setting. Every time you drop the volume level by 3 dB, you cut your power requirements in half.


As an example, I playback Master and Commander DTS at 8 dB below caibrated reference level when I want the volume to be loud. That means I only will use about 1/8 (1/2 X 1/2 X 1/2) of the calculated "reference level" power calculation for my system and my room.
J_Palmer_Cass is offline  
post #186 of 404 Old 10-23-2007, 06:03 AM
Advanced Member
 
Vinculum's Avatar
 
Join Date: Dec 2001
Location: York, Pa
Posts: 943
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 12
Quote:
Originally Posted by mpenton View Post

Perhaps you might find the answer in some older speakers http://www.oaktreeent.com/Stereo_Speakers.htm

Most of these vintage (old) speakers sported 10-12" bass drivers that made you feel the music. I owned a pair of Sansui's w/12" bass drivers and aside from causing the lights to dim when the freq. dipped down and the volume was up they were the last speakers I owned that would move furniture. Of course if you tired to put 5 of them in a normal sized room you didn't have much space left ;-)

Great links guys... I have a pair of Pioneer CS-88a speakers with rotten surrounds. I've always wanted to restore them to their former glory and present them to my Dad, from whom I acquired them in my teenage years.

If you REALLY want to go all out on dynamics and have never seen Basspig's system, you owe it to yourself to check it out at http://www.basspig.com. How about 6 EV180 18" drivers for midbass and 4 Bassmax 18" for the lowest lows driven with a true 15kwatts. Its only 2 channel, but what the heck. Better check your life insurance policy before listening

Dr V


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Vinculum is offline  
post #187 of 404 Old 10-23-2007, 06:11 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 248 Post(s)
Liked: 96
Quote:
Originally Posted by LTD02 View Post

well, the whole point of the thread was to talk about higher level SPL, particularly of the kick drum, which has a fundamental of around 63Hz. i set out the challenge to reproduce 110dB clean with lots of headroom for transients--as this level is required to *rock*. so with that said, it is more than fair to say that most "hi-fi" speakers are mid-bass deficient. then again, if your standard for SPL is much lower, say 95dB clean, then you are correct. that just wasn't the point of this thread.



With digital source material, and a requirement for 110 dB clean with plenty of headroom for transients, what kind of levels are you trying to play at? For DVD material, that is well over calibrated "reference level"!


You will go deaf playing at that kind of level in a home setting. You did not say peaks of 110 dB, you said a 110 dB level plus room for transient peaks!
J_Palmer_Cass is offline  
post #188 of 404 Old 10-23-2007, 06:23 AM
AVS Special Member
 
syswei's Avatar
 
Join Date: May 2005
Location: CT
Posts: 1,100
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by J_Palmer_Cass View Post

With digital source material, and a requirement for 110 dB clean with plenty of headroom for transients, what kind of levels are you trying to play at? For DVD material, that is well over calibrated "reference level"!


You will go deaf playing at that kind of level in a home setting. You did not say peaks of 110 dB, you said a 110 dB level plus room for transient peaks!

I don't know what the OP has in mind, but don't rock concerts typically go to >110 dB peaks? If someone knows the typical range, actually, that would be helpful....the system I'm planning is intended for both HT and music.
syswei is offline  
post #189 of 404 Old 10-23-2007, 07:01 AM - Thread Starter
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,446
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 341 Post(s)
Liked: 1022
Quote:
Originally Posted by J_Palmer_Cass View Post

You forgot that THX receivers calibrate 0 dB on the master volume to be compatible with DD DVD's that use the default Dialnorm value of -27. THX receivers boost DD by 4 dB to do this. DTS is treated in the normal way because Dialnorm is not used with DTS.

The end result is a DD (DN -27) or DTS DVD can still have peak levels near the 105/115dB level if you have a THX receiver's calibrated master volume set to 0 dB.

A DD DVD with a Dialnorm value of -31 (AKA no dialnorm like Lord of the Rings)) can peak at the 109/119 dB level if you have a THX receiver's master volume set to 0 dB.


A non-THX receiver plays back DD material 4 dB lower in volume that a THX receiver because they base their master volume levels on the Dialnorm value of -31 (AKA no Dialnorm). Typically, a DTS DVD will playback at 4 dB louder in level than a standard DD DVD (AKA default dialnorm value of -27) on a non THX receiver.



Anyhow, most everyone sets the volume control lower than the "reference level" setting, so system power requirements are often way overspecified for real world use in the typical home setting. Every time you drop the volume level by 3 dB, you cut your power requirements in half.


As an example, I playback Master and Commander DTS at 8 dB below caibrated reference level when I want the volume to be loud. That means I only will use about 1/8 (1/2 X 1/2 X 1/2) of the calculated "reference level" power calculation for my system and my room.

great info. do you know if the dd spl boost applies equally across the different THX standards (select, ultra, etc.)?

Listen. It's All Good.
LTD02 is offline  
post #190 of 404 Old 10-23-2007, 07:15 AM - Thread Starter
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,446
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 341 Post(s)
Liked: 1022
Quote:
Originally Posted by Vinculum View Post

If you REALLY want to go all out on dynamics and have never seen Basspig's system, you owe it to yourself to check it out at http://www.basspig.com. How about 6 EV180 18" drivers for midbass and 4 Bassmax 18" for the lowest lows driven with a true 15kwatts. Its only 2 channel, but what the heck. Better check your life insurance policy before listening.

that's insane. it was a good read. thanks for sharing. basspig doesn't seem to think much of speakers with 6.5" woofers that claim to rock either.

Listen. It's All Good.
LTD02 is offline  
post #191 of 404 Old 10-23-2007, 07:24 AM - Thread Starter
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,446
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 341 Post(s)
Liked: 1022
Quote:
Originally Posted by J_Palmer_Cass View Post

With digital source material, and a requirement for 110 dB clean with plenty of headroom for transients, what kind of levels are you trying to play at? For DVD material, that is well over calibrated "reference level"!

You will go deaf playing at that kind of level in a home setting. You did not say peaks of 110 dB, you said a 110 dB level plus room for transient peaks!

@105dB SPL, one might need 5-10dB of boost around 60Hz to account for "equal loudness curve" effects. so if source is 105dB, 110-115dB becomes the adjusted upper limit. i don't plan on playing the music at a constant 115dB. think of it more as ensuring sufficient margin for error than target values.

on a related point, i bet THX Loudness Plus is going to cause a lot of people problems with their systems that were designed to be maxed-out at regular THX reference.

Listen. It's All Good.
LTD02 is offline  
post #192 of 404 Old 10-23-2007, 03:37 PM
AVS Special Member
 
Drew Eckhardt's Avatar
 
Join Date: May 2001
Location: Sunnyvale, CA USA
Posts: 2,674
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
[quote=Drew Eckhardt]
Quote:
Originally Posted by LTD02 View Post

Drew,
Not sure if this is a stupid question or not, but would the effects of the reverberant sound field be reduced in a well-treated room?

Yes.

As applied to the critical distance at which direct sound and reverberant fields are equal is inversely proportional to the square root of Rt60.

Power is requirements go up with the square of distance, so power required should be inversely proportional to Rt60.

Going from 500ms to 350ms would call for 40% more power to achieve the same power or cost you 1.4dB.

Quote:


EDIT: Another possibly stupid question, is the reverberant sound field the *primary* reason why speakers are often spec'd with higher "in room" sensitivity than anechoic or is there something else at work?

No idea, although that would make sense. You're also going to pick up bass (and potentially lower midrange) when speakers are placed close to walls; that could also be taken into account.

It's a weaselly marketing thing to do, making your speakers compare favorably on paper with peoples' who haven't gotten as creative.
Drew Eckhardt is offline  
post #193 of 404 Old 10-23-2007, 04:04 PM
AVS Special Member
 
Drew Eckhardt's Avatar
 
Join Date: May 2001
Location: Sunnyvale, CA USA
Posts: 2,674
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Quote:
Originally Posted by J_Palmer_Cass View Post

You forgot that THX receivers calibrate 0 dB on the master volume to be compatible with DD DVD's that use the default Dialnorm value of -27. THX receivers boost DD by 4 dB to do this. DTS is treated in the normal way because Dialnorm is not used with DTS.

The end result is a DD (DN -27) or DTS DVD can still have peak levels near the 105/115dB level if you have a THX receiver's calibrated master volume set to 0dB.

My Lexicon THX-preamp doesn't do that, and doing so at least violates Dolby's recomendations.

To answer another post, loudness plus isn't going to be an issue either. By the time you get to 100dB the equal loudness curve is flat like a ruler and no boost is needed. You only need to bring up the lower frequencies at reduced listening levels. Like Lexicon's loudness function circa 1994.
Drew Eckhardt is offline  
post #194 of 404 Old 10-23-2007, 05:44 PM - Thread Starter
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,446
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 341 Post(s)
Liked: 1022
Quote:
Originally Posted by Drew Eckhardt View Post


To answer another post, loudness plus isn't going to be an issue either. By the time you get to 100dB the equal loudness curve is flat like a ruler and no boost is needed. You only need to bring up the lower frequencies at reduced listening levels.

while that was true with the fletcher munson curves, it is not true with the iso revision (which actually matches well with the original research on equal loudness curves).


Listen. It's All Good.
LTD02 is offline  
post #195 of 404 Old 10-23-2007, 07:32 PM
AVS Special Member
 
Drew Eckhardt's Avatar
 
Join Date: May 2001
Location: Sunnyvale, CA USA
Posts: 2,674
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Quote:
Originally Posted by LTD02 View Post

while that was true with the fletcher munson curves, it is not true with the iso revision (which actually matches well with the original research on equal loudness curves).

Groovy, although when the end result is to get back to the relative levels of sound the studio mixers had with peaks to 105dB SPL less any headroom adjustments actually listening at that level means no adjustments are required.
Drew Eckhardt is offline  
post #196 of 404 Old 10-23-2007, 07:41 PM - Thread Starter
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,446
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 341 Post(s)
Liked: 1022
[quote=Drew Eckhardt;11995500]
Quote:
Originally Posted by LTD02 View Post

while that was true with the fletcher munson curves, it is not true with the iso revision (which actually matches well with the original research on equal loudness curves). [/QOUTE]

Groovy, although when the end result is to get back to the relative levels of sound the studio mixers had with peaks to 105dB SPL less any headroom adjustments actually listening at that level means no adjustments are required.

you are probably...right.

Listen. It's All Good.
LTD02 is offline  
post #197 of 404 Old 10-24-2007, 02:44 AM
AVS Special Member
 
syswei's Avatar
 
Join Date: May 2005
Location: CT
Posts: 1,100
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Well, I care about music too.

I found a few things on the Crown site:

music has transient peaks that are 6 to 25 dB above the average level....In the calculator's Peak Headroom field, enter 6 dB for rock music that is compressed or limited, or enter 20 to 25 dB for uncompressed live music. If you can live with some short-term clipping which may be inaudible, enter 10 to 15 dB....

Listed below are typical sound pressure levels (SPLs) for various types of music. The SPL meter was set to C-weighting, slow response. You might want your system to be at least 10 dB above the background noise level to achieve a good signal-to-noise ratio.

New age: 60-70 dB
Folk: 75-90 dB
Jazz: 80-95 dB
Classical: 100 dB
Pop: 90-95 dB
Rock: 95-110 dB
Heavy metal: 110 dB.

If the sound system is inside a venue, the room reverberation will increase the SPL typically by 6 dB.


http://www.crownaudio.com/amp_htm/am...much_power.htm

Their calculator: http://www.crownaudio.com/apps_htm/d...ct-pwr-req.htm

you'll often see large touring sound companies using [using enough power] to handle 20-to-24 dB peaks without any clipping

http://www.crownaudio.com/amp_htm/am...much_power.htm

Of course, these guys sell amps.

Maybe Drew can help me with something....do CDs get that peaky (20+ dB)? SACD?
syswei is offline  
post #198 of 404 Old 10-24-2007, 03:04 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 248 Post(s)
Liked: 96
Quote:
Originally Posted by Drew Eckhardt View Post

My Lexicon THX-preamp doesn't do that, and doing so at least violates Dolby's recomendations.

To answer another post, loudness plus isn't going to be an issue either. By the time you get to 100dB the equal loudness curve is flat like a ruler and no boost is needed. You only need to bring up the lower frequencies at reduced listening levels. Like Lexicon's loudness function circa 1994.




Why do THX unit owners make up rules about THX units conforming to Dolby recommendations? They do not seem to understand that THX units conform to THX specifications. THX specifications may vary from time to time, so maybe your Lexicon unit does not apply that extra 4 dB of DD gain. Then again, maybe your Lexicon does have this extra 4 dB of gain (as in the Lexicon MC-12).


Some discussion here (last update in 2001, so this is not a recent THX development):

http://www.smr-home-theatre.org/optimode/page4.html


"In an effort to standardise the output levels of both Dolby Digital and DTS, some THX receiver and controller manufacturers (Denon being one example) are introducing a global 4dB gain to their Dolby Digital decoders, perhaps under instruction from the THX department of LucasFilm. This directly counters the 'standard' -4dB Dolby Digital dialog normalization bit and results in matched output volume levels between Dolby Digital and DTS source material. As manufacturers can reduce their internal calibration noise (against reference) by the same amount, output levels remain at the correct level unless the Dolby Digital signal carries a -0dB dialog normalization bit, in which case the outputs will have an artificial gain of 4dB."



If you own a Lexicon MC-12, then you should read your instruction manual again. The Lexicon MC-12 bases DD volume on DD source material that has a Dialnorm value of -27, not the Dolby -31 value. This is called THX reference level by THX.

The MC-12 dialog offset reads +4dB when a DD DVD encoded with a dialnorm value of -31 is used. That means that the Lexicon MC-12 will play back at the 4 dB higher level than it would have if it used the Dolby standard.

------

From the manual:

DIALOG OFFSET -27 to +4dB

Indicates the dialog normalization value applied to the input signal.
Dolby Digital input sources reproduce dialog at 27 decibels below
full-scale (-27dBFS). When the dialog normalization value of the
incoming signal is higher or lower, the DIALOG OFFSET parameter
indicates the amount of adjustment the MC-12HD makes to
normalize dialog to -27dBFS.

------

I can give you a list of DD DVD's and dialnorm values if you want to test this on your system. In a typical THX system, DTS and DD (DN -27) playback at the same volume levels. In a non-THX system, DTS and DD (DN -31) playback at the same volume levels. Perhaps THX units are not consistent, but that means you have to test your THX unit to see what how it handles "reference level".

It does not matter much unless you are comparing a THX unit with a non-THX unit, or if you insist that there is such a thing as "reference level" playback. Would that be THX reference level, Dolby reference level, or DTS reference level?
J_Palmer_Cass is offline  
post #199 of 404 Old 10-24-2007, 03:08 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 248 Post(s)
Liked: 96
[quote=Drew Eckhardt;11995500]
Quote:
Originally Posted by LTD02 View Post

while that was true with the fletcher munson curves, it is not true with the iso revision (which actually matches well with the original research on equal loudness curves). [/QOUTE]

Groovy, although when the end result is to get back to the relative levels of sound the studio mixers had with peaks to 105dB SPL less any headroom adjustments actually listening at that level means no adjustments are required.


Correct.

The soundtracks are mixed a "reference level", and the systems have a flat FR at that level.

Those loudness compensation circuits play flat at the 0dB master volume setting, and apply variable loudness compensation as you turn down the volume from reference level.
J_Palmer_Cass is offline  
post #200 of 404 Old 10-24-2007, 03:39 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 248 Post(s)
Liked: 96
Quote:
Originally Posted by syswei View Post

Well, I care about music too.

I found a few things on the Crown site:

music has transient peaks that are 6 to 25 dB above the average level....In the calculator's Peak Headroom field, enter 6 dB for rock music that is compressed or limited, or enter 20 to 25 dB for uncompressed live music. If you can live with some short-term clipping which may be inaudible, enter 10 to 15 dB....

Listed below are typical sound pressure levels (SPLs) for various types of music. The SPL meter was set to C-weighting, slow response. You might want your system to be at least 10 dB above the background noise level to achieve a good signal-to-noise ratio.

New age: 60-70 dB
Folk: 75-90 dB
Jazz: 80-95 dB
Classical: 100 dB
Pop: 90-95 dB
Rock: 95-110 dB
Heavy metal: 110 dB.

If the sound system is inside a venue, the room reverberation will increase the SPL typically by 6 dB.


http://www.crownaudio.com/amp_htm/am...much_power.htm

Their calculator: http://www.crownaudio.com/apps_htm/d...ct-pwr-req.htm

you'll often see large touring sound companies using [using enough power] to handle 20-to-24 dB peaks without any clipping

http://www.crownaudio.com/amp_htm/am...much_power.htm

Of course, these guys sell amps.

Maybe Drew can help me with something....do CDs get that peaky (20+ dB)? SACD?



None of that applies to a home setting. Those recommendations are for large live venue events!
J_Palmer_Cass is offline  
post #201 of 404 Old 10-24-2007, 06:36 AM
AVS Special Member
 
syswei's Avatar
 
Join Date: May 2005
Location: CT
Posts: 1,100
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by J_Palmer_Cass View Post

None of that applies to a home setting. Those recommendations are for large live venue events!

I understood the purpose of their recommendations. But if one is trying on occaision to reproduce (to the extent possible in a home setting) the sound of a live event, then I think the only things that would differ are the amount of room contribution (described by Crown as about 6dB in a small venue), and the compression inherent in the non-live source (CD, SACD, or whatever). If the source media is not compressed (that was basically my original question, how much compression is there, or does it vary?) then I think the numbers are very relevant, to me at least since I'm interested in music not just HT.
syswei is offline  
post #202 of 404 Old 10-24-2007, 07:05 AM
 
PULLIAMM's Avatar
 
Join Date: Aug 2005
Location: Oklahoma City
Posts: 8,516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Many of the rock concerts that I have attended (and a few in other genres like country) were much too loud. Painfully so, in fact. I would not want that at home.
PULLIAMM is offline  
post #203 of 404 Old 10-24-2007, 07:21 AM
AVS Special Member
 
syswei's Avatar
 
Join Date: May 2005
Location: CT
Posts: 1,100
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by PULLIAMM View Post

Many of the rock concerts that I have attended (and a few in other genres like country) were much too loud. Painfully so, in fact. I would not want that at home.

That's true. But let's take the range Crown offers, 95-110dB for rock concerts. If I want to listen at the low end of that, 95-100dB, but allow for the 20-24dB peaks, then I get to 115-124dB for peaks. That is, if the source CD/SACD has peaks like that. If sources do allow for those types of peaks, then I might want to incorporate that into my choice of speakers and amps.
syswei is offline  
post #204 of 404 Old 10-24-2007, 10:54 AM
AVS Special Member
 
Drew Eckhardt's Avatar
 
Join Date: May 2001
Location: Sunnyvale, CA USA
Posts: 2,674
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Quote:
Originally Posted by syswei View Post

That's true. But let's take the range Crown offers, 95-110dB for rock concerts. If I want to listen at the low end of that, 95-100dB, but allow for the 20-24dB peaks, then I get to 115-124dB for peaks. That is, if the source CD/SACD has peaks like that. If sources do allow for those types of peaks, then I might want to incorporate that into my choice of speakers and amps.

The average dynamic range on CDs was 3dB as of 2000 and getting worse by the year (this means unclipped sine waves are no longer possible on some CDs). You need to go back to 1995 to reach 6dB, 1990 for 12dB, and the birth of CDs for -18dB. Gotta love progress!!!
Drew Eckhardt is offline  
post #205 of 404 Old 10-24-2007, 11:03 AM
AVS Special Member
 
syswei's Avatar
 
Join Date: May 2005
Location: CT
Posts: 1,100
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Drew Eckhardt View Post

The average dynamic range on CDs was 3dB as of 2000 and getting worse by the year (this means unclipped sine waves are no longer possible on some CDs). You need to go back to 1995 to reach 6dB, 1990 for 12dB, and the birth of CDs for -18dB. Gotta love progress!!!


That's incredible and sad. I assume that is relative to the average SPL of the recording or something like that? Only 3dB?

Is low-fi to blame? Meaning people listening on earbuds?
syswei is offline  
post #206 of 404 Old 10-24-2007, 11:14 AM
AVS Special Member
 
Raymond Leggs's Avatar
 
Join Date: Jul 2006
Posts: 3,612
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
It's my woofer in a box!

One shall stand... One Shall Fall... - Optimus Prime
Raymond Leggs is offline  
post #207 of 404 Old 10-24-2007, 11:39 AM
Advanced Member
 
Pibbo's Avatar
 
Join Date: Sep 2007
Posts: 523
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Drew Eckhardt View Post

The average dynamic range on CDs was 3dB as of 2000 and getting worse by the year (this means unclipped sine waves are no longer possible on some CDs). You need to go back to 1995 to reach 6dB, 1990 for 12dB, and the birth of CDs for -18dB. Gotta love progress!!!

Wait, what do you mean by this? It's not like the physical CD itself has somehow lost dynamic range over the years. You're talking about the mastering that is done in the studio right? I don't understand the comment about unclipped sin waves no longer being possible...
Pibbo is offline  
post #208 of 404 Old 10-24-2007, 11:44 AM
AVS Special Member
 
oztech's Avatar
 
Join Date: May 2005
Location: Houston Texas
Posts: 7,660
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 93
i think he means the cd's of today are mastered way to hot constantly clipping.
oztech is offline  
post #209 of 404 Old 10-24-2007, 12:15 PM - Thread Starter
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,446
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 341 Post(s)
Liked: 1022
Quote:
Originally Posted by Vinculum View Post

The horn is like a megaphone, any little noise is magnified when it comes out the other end. I would say the hiss is due mostly to the amplifier noise floor. Live sound loudspeakers don't care about low volume hiss. They are going to rock the house with large crowds. Perhaps Klipsch's home speakers try to minimize this effect.

A friend of mine who owns a recording studio suggested I try out the Mackies or Event monitors. The Events were a little cheaper. He preferred the Mackies. His studio uses Adam monitors, they cost more than the Mackies.

As i said before, look at all the advantages you have with active studio monitors. No looking for the perfect amplifier - it is already done for you. The amplifiers are tuned for each individual driver. If you have ever seen the inside of one, you'll see many potentiometers for damping, level matching, ect. These are set from the factory and should not be touched. No worries about power robbing fat lossy speaker wire with high capacitance, back EMF, VSWR problems, ect. The "speaker wires" are less than 6" long inside the monitor. Crossovers are active, meaning no phase shift anomalies due to capacitance and inductance of a passive crossover. Biamped naturally, EQed flat out of the box in the nearfield, active limiting & thermal circuits - don't worry about bottoming drivers, because when the limit light comes on you just back them down a little bit. Balanced inputs for low noise on long runs. Balanced connections use common mode rejection techniques to lower noise and the fact you aren't attempting to transfer power from an amplifier halfway across the room to a driver. XLR cables are CHEAP compared to jumper cables needed for passive speakers. Plenty of room contour controls on the back panel. Semi-servo design for the low frequency transducer. Oh and they are THX pm3 certified. I guess i could drone on and on about the benefits of active studio monitors as I have in the past on this forum. Most people have their minds made up before they even buy anything and these facts just fall on deaf ears most of the time. I know I was sold after hearing them! (even tho i bought them before hearing them - I trusted a recording engineer, someone who's income depends on listening and probably should have a better ear than most people)

All these things make for an extremely accurate speaker, which is what I wanted. Now if you value entertainment (SPL?) over accuracy, then you might look into something else. But I might add the Mackies are rated at 120dB per pair. If you offload some bass onto some subwoofers, you can get a little more SPL and headroom out of them. I think a PAIR of HRS120's under EACH monitor would just knock you out of your shoes, but I haven't heard them configured as such. Everyones preference and environment differs of course. In my office I have a pair of HR624's on my PC. They sound so good by themselves in a small room, and I keep cranking up the volume. I have never seen the limit light come on. They get uncomfortably loud before they stress out. As far as accuracy goes, I'm sure my office setup is better for critical listening. The room isn't influencing the sound very much because of the size and distance to the monitors. Larger rooms need more work. Lots of work to sound as good. Room treatments are an art by themselves. Check out a book called "The Master Handbook of Acoustics". Everyone should have a copy.

Hey Syswei, Thanks for the link! Good read. I was impressed by the mic technique for the servo. I wish I could hear some of those bad boys!

I've babbled on enough for now, I need to get away from the computer for a few hours and do something around the house!

Dr V

i was reading this great post again and realized that i have no idea what "VSWR probems" are. could someone explain or point to a source?

Listen. It's All Good.
LTD02 is offline  
post #210 of 404 Old 10-24-2007, 12:35 PM - Thread Starter
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,446
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 341 Post(s)
Liked: 1022
[quote=Drew Eckhardt;11993416]
Quote:
Originally Posted by Drew Eckhardt View Post


Yes.

As applied to the critical distance at which direct sound and reverberant fields are equal is inversely proportional to the square root of Rt60.

Power is requirements go up with the square of distance, so power required should be inversely proportional to Rt60.

Going from 500ms to 350ms would call for 40% more power to achieve the same power or cost you 1.4dB.


I was playing around with this calculator, which estimates the Rt60 value in seconds for a variety of room shapes/materials. I find that acoustically bright rooms are around 500ms, while very accoustically dead roooms are down around 150ms for 1k frequency.

Do these values seem roughly correct to you?

Listen. It's All Good.
LTD02 is offline  
Reply Speakers

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off