What does "reference" mean - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 28 Old 07-26-2013, 10:14 PM - Thread Starter
Senior Member
 
Sweetmeat's Avatar
 
Join Date: Aug 2011
Location: Lincoln, NE
Posts: 414
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 13
I've read many threads that use this term, but I've never seen a definition for it. Could someone give the answer for dummies?

Samsung TV - PN59D8000 - wall mounted
HW50ES projector w/electric Elite 120" ceiling mounted screen (drops in front of plasma)
Receiver - Yamaha RX-A3000
Front Speakers - B&W CM9, Center - B&W CMC2, Surrounds - B&W CM5
SVS PB12+, SVS PB13 Ultra
Sweetmeat is offline  
Sponsored Links
Advertisement
 
post #2 of 28 Old 07-27-2013, 01:26 AM
Member
 
stereo2.0's Avatar
 
Join Date: Jul 2006
Location: Port Coquitlam, BC
Posts: 177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 20
If you're talking about the audio reference level (loudness) of a properly calibrated audio-video surround sound system, then reference refers to the maximum output sound level that a movie can produce at the listening position, and should exactly match the loudness level that the audio recording Engineer intended for the audience to experience.

If the volume control on a AV receiver is set to reference (0 dB on the front panel display), it is possible to obtain a maximum loudness level at the listening position of 105 dB SPL from a main/surround speaker and 115 dB SPL from a subwoofer. (The subwoofer can go louder because the LFE channel has 10 dB more headroom)
Of course when a movie is showing a quiet scene then it will be quieter at the listening position too, but when things get loud, the levels quoted above will be the loudest any channel can put out.

Most home theater listeners find reference to be too uncomfortably loud and end up setting the volume control to a quieter setting. (I just watched Terminator2 at -25 dB tonight because it was late and the neighbours were already asleep)
Likewise, when calibrating a home surround sound system with a microphone, the test tone levels are only output at 75 dB SPL when the volume control is set to reference because users complained the tones were too annoying at any higher levels. (Though theaters still calibrate at 85 dB SPL because the audience isn't even there when they calibrate their sound system)
mtn-tech likes this.
stereo2.0 is offline  
post #3 of 28 Old 07-27-2013, 07:50 AM
AVS Special Member
 
mtn-tech's Avatar
 
Join Date: Feb 2013
Location: Nevada
Posts: 1,102
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 196 Post(s)
Liked: 156
When talking about system or component performance, a "reference" is a standard by which others are judged

Asked and answered here: http://www.avsforum.com/t/613533/reference-systems

2-Ch (HT L/R): Oppo BDP-105 BD, Adcom GFP-750 pre, Bryston 10B Sub Xover, Bryston 4BSST2 / Paradigm Signature S4 v.2 (L/R), (2) SVS SB12-NSD (Subs)
Home Theater: Bryston 4BSST2 amp / Paradigm CC-590 (C), Outlaw 7700 amp / (4) Def Tech UIW-RSSII (LS/RS/LB/RB), Samsung 46” 3D LCD
mtn-tech is offline  
post #4 of 28 Old 07-27-2013, 09:17 AM - Thread Starter
Senior Member
 
Sweetmeat's Avatar
 
Join Date: Aug 2011
Location: Lincoln, NE
Posts: 414
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 13
Thank you. This is the answer I was looking for.

So, to confirm my understanding, anytime your volume control is set to 0 dB, that means you're listening at the reference level? Or do you need to have SPL at 105 dB?

The listening distance from your speakers obviously effects the SPL at that position, so 0 dB on the volume control may not produce 105 dB SPL at that position.

Samsung TV - PN59D8000 - wall mounted
HW50ES projector w/electric Elite 120" ceiling mounted screen (drops in front of plasma)
Receiver - Yamaha RX-A3000
Front Speakers - B&W CM9, Center - B&W CMC2, Surrounds - B&W CM5
SVS PB12+, SVS PB13 Ultra
Sweetmeat is offline  
post #5 of 28 Old 07-27-2013, 10:31 AM
AVS Special Member
 
mtn-tech's Avatar
 
Join Date: Feb 2013
Location: Nevada
Posts: 1,102
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 196 Post(s)
Liked: 156
Quote:
Originally Posted by Sweetmeat View Post

anytime your volume control is set to 0 dB, that means you're listening at the reference level?


At the 0dB setting, your AVR may output the level required to drive a reference speaker to a defined reference level, but your actual loudness would of course depend on the sensitivity / efficiency of your speakers and the specifics of your listening room. As "2.0" said, proper calibration of your system could match your 0dB setting with an in room output to the reference level - then the answer would be yes.

2-Ch (HT L/R): Oppo BDP-105 BD, Adcom GFP-750 pre, Bryston 10B Sub Xover, Bryston 4BSST2 / Paradigm Signature S4 v.2 (L/R), (2) SVS SB12-NSD (Subs)
Home Theater: Bryston 4BSST2 amp / Paradigm CC-590 (C), Outlaw 7700 amp / (4) Def Tech UIW-RSSII (LS/RS/LB/RB), Samsung 46” 3D LCD
mtn-tech is offline  
post #6 of 28 Old 07-27-2013, 10:47 AM
AVS Special Member
 
commsysman's Avatar
 
Join Date: Dec 2007
Location: Southern California
Posts: 5,353
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 167 Post(s)
Liked: 266
It is ridiculous to assert that setting a receiver's gain to "0db" results in some "reference" sound level; that is ridiculous.

That is only an arbitrary amplifier gain setting, nothing more. The sound level that results from that setting involves several other variables, and will vary a lot.

You can set the receiver to 0db and you will get a certain volume level with speakers that have an 86db/watt sensitivity, and then if you switch to some speakers with a 90 db/watt sensitivity, the volume will be much louder with the receiver still set to 0db.

You can also change from one signal source to another, and if the sources put out somewhat different voltage levels, which is probable, you will again get different volume levels in the room from the two different sources with the receiver still set to 0db.

Those are just two of the obvious variables that will result in different sound levels; there are others.

It would be just as dumb to assert that setting the volume control knob in the "12 o'clock" position on an amplifier always gives the same volume...for the same reasons stated above.

The word "reference" is in the dictionary; you can look it up.





Quote:
Originally Posted by Sweetmeat View Post

Thank you. This is the answer I was looking for.

So, to confirm my understanding, anytime your volume control is set to 0 dB, that means you're listening at the reference level? Or do you need to have SPL at 105 dB?

The listening distance from your speakers obviously effects the SPL at that position, so 0 dB on the volume control may not produce 105 dB SPL at that position.
commsysman is offline  
post #7 of 28 Old 07-27-2013, 11:56 AM
AVS Special Member
 
jdcrox's Avatar
 
Join Date: Jan 2003
Location: Cape Cod, MA
Posts: 2,025
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Liked: 64
Commsysman, if you run your A/V receiver's setup program, it should set 0 to reference. Same as balancing your speakers the old way, using a db meter and the built-in test tones. If properly done, it will result in 0 being at least close to the 105db "reference".
jdcrox is offline  
post #8 of 28 Old 07-27-2013, 12:03 PM - Thread Starter
Senior Member
 
Sweetmeat's Avatar
 
Join Date: Aug 2011
Location: Lincoln, NE
Posts: 414
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 13
[quote name="commsysman" url="/t/148337

The word "reference" is in the dictionary; you can look it up.
[/quote]

From.Dictionary.com -

"1. an act or instance of referring

2. a mention; allusion.

3. something for which a name or designation stands; denotation.".

None of those definitions mean what people ate saying in their context, which.is the reason for my question. Most people have said things like "I listen at reference levels". What defines reference level?

Samsung TV - PN59D8000 - wall mounted
HW50ES projector w/electric Elite 120" ceiling mounted screen (drops in front of plasma)
Receiver - Yamaha RX-A3000
Front Speakers - B&W CM9, Center - B&W CMC2, Surrounds - B&W CM5
SVS PB12+, SVS PB13 Ultra
Sweetmeat is offline  
post #9 of 28 Old 07-27-2013, 01:06 PM
AVS Special Member
 
BIslander's Avatar
 
Join Date: Jul 2005
Posts: 8,659
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 123 Post(s)
Liked: 138
commsysman - Reference is done in reference to specific standards so that the output levels of the playback equipment match the output levels of the source material. While most people calibrate so that reference is at 0dB on the master volume, you can set the reference point at -10dB or any other point on the dial (within reason). Of course, if you change speakers or any other piece of equipment in the playback chain, you need to calibrate for the new equipment.

I am curious, though, about the point you are trying to make.
BIslander is online now  
post #10 of 28 Old 07-27-2013, 01:17 PM
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,530
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 851 Post(s)
Liked: 1205
Quote:
Originally Posted by BIslander View Post

commsysman - Reference is done in reference to specific standards so that the output levels of the playback equipment match the output levels of the source material. While most people calibrate so that reference is at 0dB on the master volume, you can set the reference point at -10dB or any other point on the dial (within reason). Of course, if you change speakers or any other piece of equipment in the playback chain, you need to calibrate for the new equipment.

I am curious, though, about the point you are trying to make.

I think you'd be pretty close if you assumed that he hos no hands-on experience and has never seriously studied the modern self-calibration facilities that come with just about any new AVR.
arnyk is offline  
post #11 of 28 Old 07-28-2013, 04:34 AM
AVS Special Member
 
BIslander's Avatar
 
Join Date: Jul 2005
Posts: 8,659
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 123 Post(s)
Liked: 138
Quote:
Originally Posted by Sweetmeat View Post

Most people have said things like "I listen at reference levels". What defines reference level?
It means setting your equipment to define the point where the SPL at the listening position matches the SPL of the mixing stage.

You do this by setting the master volume of the receiver at 0dB. Then, play test tones for each channel. The tones in receivers are usually set for 75dB while the ones on calibration discs may be 85dB. As you play the tones, adjust the trim level on each channel so that your SPL meter at the listening position reads either 75 or 85dB, depending on the source of the test tones. "Listening at reference" on your system will then mean playback with the master volume at the 0dB point you used for your calibration. If you have a receiver with an auto calibration system, it will do all of this for you.

One other note: 0dB is considered "full scale", where a full range channel outputs a maximum of 105dB and LFE tops out at 115dB. The negative numbers on the volume displays of most receivers show the output level below full scale. -20dB on the master volume means a sound that would play at 105dB at reference will be output at 85dB instead.

Reference level is uncomfortably loud in most home settings and people generally listen at much lower levels. That can present problems because some sounds that are perfectly audible at reference may get buried under other sounds at lower volumes. Some THX processing modes and newer techniques such as Dynamic EQ are designed to compensate for some of the differences associated with lower, non-reference volume levels in home theaters.

There's an audio expert who posts at blu-ray.com who has written a much more comprehensive explanation of reference levels and how to properly calibrate home systems.

http://forum.blu-ray.com/showthread.php?t=38765
BIslander is online now  
post #12 of 28 Old 07-28-2013, 05:53 AM
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,530
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 851 Post(s)
Liked: 1205
Quote:
Originally Posted by BIslander View Post

Quote:
Originally Posted by Sweetmeat View Post

Most people have said things like "I listen at reference levels". What defines reference level?
It means setting your equipment to define the point where the SPL at the listening position matches the SPL of the mixing stage.

You do this by setting the master volume of the receiver at 0dB. Then, play test tones for each channel. The tones in receivers are usually set for 75dB while the ones on calibration discs may be 85dB. As you play the tones, adjust the trim level on each channel so that your SPL meter at the listening position reads either 75 or 85dB, depending on the source of the test tones. "Listening at reference" on your system will then mean playback with the master volume at the 0dB point you used for your calibration. If you have a receiver with an auto calibration system, it will do all of this for you.

One other note: 0dB is considered "full scale", where a full range channel outputs a maximum of 105dB and LFE tops out at 115dB. The negative numbers on the volume displays of most receivers show the output level below full scale. -20dB on the master volume means a sound that would play at 105dB at reference will be output at 85dB instead.

Reference level is uncomfortably loud in most home settings and people generally listen at much lower levels. That can present problems because some sounds that are perfectly audible at reference may get buried under other sounds at lower volumes. Some THX processing modes and newer techniques such as Dynamic EQ are designed to compensate for some of the differences associated with lower, non-reference volume levels in home theaters.

There's an audio expert who posts at blu-ray.com who has written a much more comprehensive explanation of reference levels and how to properly calibrate home systems.

http://forum.blu-ray.com/showthread.php?t=38765

I'll quibble with the expert because of his recommendations for test signals. Pink noise and steady state sine waves can give you misleading results because they can be affected by the frequency response of the audio system. Remember we are working with acoustic measurements which can change dramatically for trivial reasons like you moved the SPL meter a few inches.

IMO Audessey does it right when they use chirps (swept tones) for all of their measurements. That is probably not possible for home use in simple systems that don't have sophisticated analytical facilities. One other simple-to-use alternative is narrow band filtered noise. I don't recall if REW has any special analysis features for level setting but it does have good analytical tools.
arnyk is offline  
post #13 of 28 Old 07-28-2013, 09:30 AM
AVS Special Member
 
JHAz's Avatar
 
Join Date: Mar 2009
Posts: 4,099
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 143 Post(s)
Liked: 172
Quote:
Originally Posted by commsysman View Post

It is ridiculous to assert that setting a receiver's gain to "0db" results in some "reference" sound level; that is ridiculous.


and yet those morons that build and use multimillion dollar sound mixing stagesi nsist on calibrating them to reference, and recalibrating frequently to assure they are still at reference.

OF course, without knowing what movie reference is (I had less than no clue when I first started hanging out here) "reference" seems meaningless. Actually it's a real, man-made thing that is used in the business to (at lest theoretically) allow your local theater to play back any movie at exactly the volume level the mixers/directors/producers settled upon in the aforementioned multimillion dollar mixing stage. These days it's defined against digital media, which makes it easier to me to grok. It simply states that (for mixing stage setups) using a bandwidth limited pink noise tone encoded at -20 DbFS (Full Scale being the "loudest" you can encode in digital) must yield an SPL of 85 dB at the main listening position, for each speaker. It's just a tool that helps make movies more translatable. Like agreeing on how long an inch is . . .
JHAz is offline  
post #14 of 28 Old 07-28-2013, 10:29 AM - Thread Starter
Senior Member
 
Sweetmeat's Avatar
 
Join Date: Aug 2011
Location: Lincoln, NE
Posts: 414
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 13
Quote:
Originally Posted by JHAz View Post

Quote:
Originally Posted by commsysman View Post

It is ridiculous to assert that setting a receiver's gain to "0db" results in some "reference" sound level; that is ridiculous.


and yet those morons that build and use multimillion dollar sound mixing stagesi nsist on calibrating them to reference, and recalibrating frequently to assure they are still at reference.

OF course, without knowing what movie reference is (I had less than no clue when I first started hanging out here) "reference" seems meaningless. Actually it's a real, man-made thing that is used in the business to (at lest theoretically) allow your local theater to play back any movie at exactly the volume level the mixers/directors/producers settled upon in the aforementioned multimillion dollar mixing stage. These days it's defined against digital media, which makes it easier to me to grok. It simply states that (for mixing stage setups) using a bandwidth limited pink noise tone encoded at -20 DbFS (Full Scale being the "loudest" you can encode in digital) must yield an SPL of 85 dB at the main listening position, for each speaker. It's just a tool that helps make movies more translatable. Like agreeing on how long an inch is . . .

OK, so if I have SPL of 85db at the main listening position, I am listening at the reference level?

If that's true, I would think (although I'm nowhere close to being an expert) that most speakers could achieve that, which makes me wonder why some speakers are referenced as "reference" speakers and others are not.

Samsung TV - PN59D8000 - wall mounted
HW50ES projector w/electric Elite 120" ceiling mounted screen (drops in front of plasma)
Receiver - Yamaha RX-A3000
Front Speakers - B&W CM9, Center - B&W CMC2, Surrounds - B&W CM5
SVS PB12+, SVS PB13 Ultra
Sweetmeat is offline  
post #15 of 28 Old 07-28-2013, 11:03 AM
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,530
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 851 Post(s)
Liked: 1205
Quote:
Originally Posted by Sweetmeat View Post

Quote:
OF course, without knowing what movie reference is (I had less than no clue when I first started hanging out here) "reference" seems meaningless. Actually it's a real, man-made thing that is used in the business to (at lest theoretically) allow your local theater to play back any movie at exactly the volume level the mixers/directors/producers settled upon in the aforementioned multimillion dollar mixing stage. These days it's defined against digital media, which makes it easier to me to grok. It simply states that (for mixing stage setups) using a bandwidth limited pink noise tone encoded at -20 DbFS (Full Scale being the "loudest" you can encode in digital) must yield an SPL of 85 dB at the main listening position, for each speaker. It's just a tool that helps make movies more translatable. Like agreeing on how long an inch is . . .

OK, so if I have SPL of 85db at the main listening position, I am listening at the reference level?

You left out the part about the recording level being -20 dB below maximum.
Quote:
If that's true, I would think (although I'm nowhere close to being an expert) that most speakers could achieve that, which makes me wonder why some speakers are referenced as "reference" speakers and others are not.

Yes playing a recording of a -20 dB recorded tone at 1 KHz would be no sweat at 85 dB SPL. .

But to handle the whole recording your L, C & R speakers have to be able to make 105 dB SPL each at the listening location for the maximum possible peaks on the recording. Your LFE channel has to be able to go 10 dB higher than that, which would be 115 dB SPL.

Your L & R speakers might need to develop more like 110 dB @ 1 meter once you include losses and gains in the room. If you have average efficiency speakers, this would take about 100 watts peak music power. This is all pretty doable. That subwoofer that does 115 dB SPL @ 20 Hz cleanly would probably be the money pit. Again doable, but it will cost ya!

If you have an AVR that is properly calibrated using Aydyssey, MCACC or YPAO your volume control should be automatically calibrated to this standard +/- any manual adjustments.
arnyk is offline  
post #16 of 28 Old 07-28-2013, 11:07 AM
AVS Special Member
 
BIslander's Avatar
 
Join Date: Jul 2005
Posts: 8,659
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 123 Post(s)
Liked: 138
You want an SPL of 85dB when playing 85dB calibration tones, which is certainly possible with any decent speaker. Calling something a "reference" speaker is just marketing verbiage.
BIslander is online now  
post #17 of 28 Old 07-28-2013, 04:11 PM - Thread Starter
Senior Member
 
Sweetmeat's Avatar
 
Join Date: Aug 2011
Location: Lincoln, NE
Posts: 414
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 13
OK, so calibrating is done at 75db (or sometimes at 85db) but reference is 105db from all frequencies at the listening position, correct?

Samsung TV - PN59D8000 - wall mounted
HW50ES projector w/electric Elite 120" ceiling mounted screen (drops in front of plasma)
Receiver - Yamaha RX-A3000
Front Speakers - B&W CM9, Center - B&W CMC2, Surrounds - B&W CM5
SVS PB12+, SVS PB13 Ultra
Sweetmeat is offline  
post #18 of 28 Old 07-28-2013, 04:53 PM
AVS Special Member
 
BIslander's Avatar
 
Join Date: Jul 2005
Posts: 8,659
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 123 Post(s)
Liked: 138
Not exactly. Sort of.

When your receiver's master volume is set to 0dB, you want your SPL meter to measure at the same level as the tones you are using (75dB or 85dB, depending on the source of the tones). Calibration tones could be set to play at 105dB, but that would be intolerably loud and equipment would have a hard time playing back that loud for sustained periods. The actual level of the tones doesn't much matter. You just want the SPL of the playback system to match the output level of the tones when the master volume is set at 0dB.

Reference does not mean 105dB. At reference, the maximum output of a full range channel will be 105dB because anything louder than that will clip. But, the actual output will rarely be that loud. Dialog will likely be in the 75-80dB range, louder when people are yelling, quieter when they are whispering. You'll only hit the upper end of the scale for things like really big explosions.
BIslander is online now  
post #19 of 28 Old 07-29-2013, 03:16 PM
AVS Special Member
 
Nyal Mellor's Avatar
 
Join Date: Aug 2010
Location: SF Bay Area, California, USA
Posts: 1,112
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 133 Post(s)
Liked: 98
My understanding of reference level: THX Reference Level Explained.

Acoustic Frontiers: design and creation of high performance listening rooms, home theaters and project studios for discerning audio/video enthusiasts.
Nyal Mellor is offline  
post #20 of 28 Old 07-29-2013, 05:20 PM
AVS Special Member
 
Ivan Beaver's Avatar
 
Join Date: Dec 2005
Posts: 1,648
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked: 44
Quote:
Originally Posted by Nyal Mellor View Post

My understanding of reference level: THX Reference Level Explained.
Except it gets a bit more complicated.

If you use pink noise to set a level-then the peak level (as defined in the article as 105dB) will either be 6 or 10dB (depending on the crest factor of the noise) than the "average" that is read on a typical meter.

Even the fast response is not fast enough to respond to the peaks.

Danley Sound Labs

Physics-not fads
Ivan Beaver is offline  
post #21 of 28 Old 07-30-2013, 04:16 AM
AVS Special Member
 
mtbdudex's Avatar
 
Join Date: May 2007
Location: SE Michigan
Posts: 4,908
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 77 Post(s)
Liked: 349
Nice to see Nyal and Ivan in this thread, 2 of the people who Grok at a higher level "What does "reference" mean".

There is good discussion in this thread, I suggest the OP spend 10 minutes cruising thru the first couple of pages to grasp - Grok - it further.
http://www.avsforum.com/t/1387083/list-of-reference-level-high-sensitivity-spl-speakers
A good summary of terms in the 2nd post is quoted below:
Quote:
Originally Posted by Eyleron View Post

Last Updated March 26, 2012

Why?

This is intended to be a reference list of speakers with higher sensitivity, capable of higher SPL, and more importantly yield great dynamics, which are some of the desirable traits for home theater speakers. I use "low distortion" as a term here because many people are experiencing clipped peaks and distortion without realizing it. They'd never think so, because they don't play near reference level. So this document can be helpful in showing what different speakers will output with what watts.


This is borne out of my own quest for such speakers, and there appears to be rising interest in this category. I often see a few makes and models thrown out as options in threads, but inconsistently, and the thread often dies with people wanting more.

What It Is

This is mainly an aggregate of manufacturers' own specs allowing one to compare speakers in the context of their output and the watts required for reference level at 12 feet, and how loud it'll get with the typical 100w receiver. It's more of an educational tool than a shopping tool. Hence, I've included many speaker that people have asked to be included, such as speakers that were known for high output but may be discontinued and difficult to acquire today. There are also "gray area" speakers that almost achieve reference level. There's another list of speakers that I had initially included for comparison sake, but are not reference level capable.


The list is also filtered through my editing and weighting in the scoring columns, and some specs have been corrected for comparison purposes or where reviews have consistently found the manufacturer data to be wrong or misleading.

What It's Not

This is not a definitive list, as every speaker cannot be included. I add them as I come across them or people recommend them.


This is not a definitive shopping tool. The pricing might sometimes be average new prices, or reported dealer prices, or MSRP. Your own shopping will likely find different prices.


It's not always perfectly accurate; just as professional publications print corrections every month, I too make copy-paste mistakes or misinterpret data. I try to ask where I have questions, and I try to add comments on individual cells to qualify the data (e.g. where the sensitivity was dropped 3dB to get from a reported in-room to anechoic).


This is not a list of speakers by quality. Maximum output and dynamic capability at higher output are only a couple attributes of speaker among many. And even those may be meaningless to many people, in the same way that an automobile's top speed has no bearing on one's car purchase if one will never drive it that fast, except as bragging rights. If you never listen louder than -15dBFS from reference level, then most speakers of middlin' efficiency and limited power handling will work fine, because you'll only send the speakers a few watts of power.

Reference Level?

The term is often mentioned as a benchmark of output. It's really just what it says, a reference level. It is not the "ideal level" or the "best level." Although this is a gray area, as supposedly many commercial theaters are supposed to be calibrated and capable to play at this level, and film soundtrack mastering is performed at this level.


Reference Level, 0dBFS (0dB Full Scale (digital), is the maximum level the soundtracks can be recorded at for any given channel. It equates to SPL peak output for each five or seven channels of 105dB and 115dB for the LFE channel at the listening position. The soundtrack will rarely reach this level, but it's a reference point. Even if people rarely play at this loud level, it's good to calibrate so that you know where your volume is at for comparison purposes. This is loud, but in a better-treated room with better equipment, it sounds more natural. The dynamic peaks are loud enough that it the sounds will affect you at a more instinctual level. It also ensures that the softest sounds are above the system's (which includes the room, HVAC, etc.) noise floor.


The requirements to reach reference level, or any volume, differ from speaker to speaker, amp to amp, room to room, and with different seating distances.


It's also a benchmark elsewhere, such as for THX certification.

Isn't that insanely loud?

Remember that the 105dB is for peaks, not average levels, which are 85dB. The peaks are brief, transient spikes, and they don't harm hearing.


In the real world:
  • the dishes clattering might be 90-ish decibels (1 meter)
  • a roaring passenger car might be 100dB (1 meter).
  • standing next to a grand piano 109dB.
  • a rock concert 111dB (40 feet away)
  • drum set (at moment of strike) 125dB


You can see it's not outlandish in an action movie to have brief peaks of sound of 100 or 105dB to simulate at a much lower level the sounds of the action.


The other issue is perception of loudness. Much of the time, when we say a theater system is "too loud" we at least partially mean, "It sounds bad!" As typical weaker systems are tasked with trying to play beyond their limits, they produce bad sound, in the form of distortion. We don't like distortion, so we say, "it's too loud!" What we're really judging is the system, not the SPL per se. Picture driving in a poorly-built vehicle at too high a velocity for the vehicle and the road. All the smoke, vibration, skidding, bad engine sounds, the out of control feeling, add up to a bad experience. An automobile that is more capable would yield a much better experience at the same speed. And a better road (theater room) would make it better still.

Why is this a big deal?

Most home systems cannot approach this level. As stated above, -15dBFS (15 decibels below reference level) is fairly easy to achieve. The relationship between watts and SPL is not linear. 3dB increase of SPL requires twice the watts. Twice the loudness is 10dB, and that's ten times the watts. Fortunately, even a few watts into an inefficient speaker will produce enough sound for casual TV watching, background music, or critical music listening in a quiet environment.


Unfortunately, the requirements are exponentially higher when you want to listen closer to reference level, where typical speakers will require hundreds or even thousands of watts! When the speakers and amps are not up to the task, we get reduced output and distortion.

Data

I'll be pasting the list of speakers and what data I can in a more limited format, but I'm maintaining the master as a Google Docs spreadsheet which has the most information.

Color Coding

I used conditional formatting to come up with color coding. Dark red = bad, oranges less bad, yellow almost good enough, greens are good, blues are better, and dark blues are superlative. Lots of subjective thinking here, as I realize that sensitivity is neither bad or good, but rather a design decision. However, it plays such a huge part in speakers' ability to output high spl with low distortion, that I'm willing to judge it. The colors have been "normalized" when I saw huge gaps in the colors or a cluster of a lot of numbers using the same color.

Fields / Columns
Manufacturer

Model

Type: Floor, Stand, Center, Surround

Orig Purpose: Indicates what the speaker was originally manufactured for. Monitor (studio or stage monitor, usually for near to midfield. Maybe I should break that up into near, midfield, and farfield monitors?), Home, Stage

Price Used (each): When the speaker has been discontinued.

Price New (each): I either take the manufacturer's MSRP, or find it on dealer websites and try to take an average, or at worst I have to dig through forum posts.

Active / Passive: Active speakers have built-in amps, or are intended to connect to rack-mounted amps with tailored DSP. Has implications for all the numbers, because I usually have to extrapolate the sensitivity, for which I use low frequency (amp, woofer, SPL, etc.). I need more guidance on how to treat these.

Sensitivity dB (anechoic): These numbers are given with different or no qualifiers by manufacturers. Anechoic, in-room, in-corner, two speakers, 1m, 2m, half-space, 1w, 4ohm 1w, 2.83v 4 ohm... Fortunately, pro speakers usually list the max peak SPL, so using that and their stated peak watt handling, I can extrapolate what the sensitivity is (this is required for active speakers) or whether they meant half space or full space. For instance, the Hsu HB-1 is 92dB half space, so I dropped it 3dB. Unfortunately, this isn't exact...I see some manf. specify the in-room sensitivity as 4dB higher than anechoic. Some manufacturers are anecdotedly known in forums, and tested in reviews, to be off on sensitivity by 3-4dB. For those known lines, I simply reduce the number by 3dB. But if people could come forward with more reviews on specific speakers reporting the tested sensitivity, I'll correct numbers.


For 4 ohm speakers with sensitivity given as dB @ 2.83v/1m, I have normalized for comparison to the 8ohm speaker by dropping sensitivity 3dB. Ideally, manufacturers give sensitivity as dB @ 1w/1m.

Watts to Reach 105dB 12 ft LP: Gives you an idea of what kind of power would be required for reference level peaks. This is "The number of watts you'll need to send the speaker to reach a 105dB peak with a listening position 12 feet away, in an anechoic room, using the anechoic sensitivity." So, three parameter assumptions: desired level of peaks, distance, and type of room. In the Calcs sheet I can change those numbers, and some day I'll figure out how to present this data and let YOU override those numbers.


When you see that Speaker X would need 1,000 watts to reach reference peak, you can judge whether you'd ever have that big of an amp.

% Watts Peak: This is the percent of the speaker's peak power handling that is required to reach the 105dB from 12 feet. It's one thing if Speaker X needs 1,000 watts, and you're even willing to provide that power. But it's all moot if the manufacturer states that the speaker can only handle 200 watts peak!

100 watts dB: The SPL you'll get from the speaker 12 feet away, when you feed it 100 watts. This is another number that educates, because 100 watts is such a typical number for receivers.


Program Watts: Usually between continuous and peak power handling. I don't even include continuous, because most of these speakers will handle 85dB continuous output just fine. Continuous is with a sine wave with a 3dB crest factor, so maybe it is representative of the worst compressed music out there. But generally Program is more representative of real material. Many pro speakers give this datum. JBL, Danley, etc. When they only give continuous and peak, I split the difference.

Program Watts dB (12ft): SPL you'll get from the speaker fed program watts @ 12 feet. Again, some day the 12 feet will be a distance variable that the public can change and tailor the numbers for their own needs.

Peak Watts: Usually 4x Continuous, 2x Program, so when not given, I extrapolated.


It's not the average output levels that most speakers struggle with; it's the peaks. The amp either clips on them, softly (not noticeable) or harshly. As FOH says, this is "insidious" when you don't realize it, but it makes the music / program less dynamic, less real, less scary, when you're missing those transient from plucked strings, piano notes, drum hits, or the gun shot. Or the speaker can't handle the peak watts required and distorts, bottoms out, or leaves the magnetic gap a big and doesn't give us the volume we should have (if just the woofer does this, then the sound gets more bright).


Some manufacturers test to give this number. This is difficult to test, as we're not talking about a continuous signal (which would be continuous power handling). The peak power handling is so much higher because the voice coil has time to cool between peaks. Sometimes the number means "this is where the speaker might be destroyed." Other times it means "this is where the distortion is unacceptable (whatever that means)." Others: "This is where this type of distortion reached 10%, with this type of signal," which is obviously a much better qualification of the number (this is rare, unfortunately).

Peak dB: The SPL you'll get when sending quick peaks to the speaker at the level of the Peak Watts. Lately this is how the list is sorted.

Scores: These are different scorings with different weights for sensitivity, price, power handling, etc.

Active Specs: For active speakers, which include amplifiers, or require specific outboard amps with DSP, the watts for each driver are listed: Low Frequency, Mids, High Frequency.

Freq -3dB: The -3dB point of the speaker, which is the frequency range. I used to list just the lower point, but then I noticed some pro cinema speakers rolled off a 16kHz. Sometimes this point is interpolated for speakers where only a -6dB or -2dB point is given in literature.

Distortion: I wish this was given more often, and I wish it was given at a higher output level stressing the speaker more. This column was added later, so I intend to return to many of the speakers' literature, or search for lab tests, and present distortion numbers. Soundstage has such measurements.

Ohms: Nominal impedance.

Dispersion Degrees: More applicable for horn speakers. The horizontal dispersion is given first. Generally one wants to limit dispersion to the floor and ceiling. Depending on application, you may want more horizontal dispersion (like for a center), or less horizontal (if you're trying to minimize side wall reflections).

LF (in): Number and size in inches of the low frequency drivers.

MF (in): Number and size in inches of the mid frequency drivers.

HF (in): Number and size in inches of the high frequency drivers.

Wave-guide: Short description of the wave guide (horn), e.g. "ellip CD" = Elliptical wave guide with a Compression Driver.

URL: Web page address of specs.

Notes / Misc: Other ocassional information.

Range of Speakers

Included are the common highly-touted reference level speakers, and pro-audio speakers, and also some that simply are often mentioned as great for theater.


Many speakers will not be horns. Many will be ugly. Some we find will never have been considered for home theater, and some of those may be new-found gems (hopefully!), while others will be found to be completely unsuitable for home theater. We may want to keep them in the list with explanation of why they're inappropriate. Some will be capable of reference level with outboard amps. Some will clearly not reach RL at 12 feet, but may be suitable for someone wanting -5db without distortion, for example.

How Calculated

Speaking of which, I started off using the SPL calculator [URL=http://http//myhometheater.homestead.com/splcalculator.html]here[/URL] and I'm calculating with one speaker, away from walls, at 12 feet.


Later, as the errors mounted in having to calculate each speaker manually, I incorporated formulas, such as =(10^((Calcs!B$3-(I25+(20*log(3.2808399/Calcs!B$2))))/10)).

A Work in Progress
  • I don't have all of the sampling of commonly suggested theater speakers yet. Sometimes I'm aware of a speaker, but I don't have data on its specs yet. Write in recommendations. Point me to reviews! Correct my mistakes!
  • While I'm listing the manufacturers' recommended input wattages, I'm unsure about how to translate different manufacturer's specs, such as continuous, program, and peak. Of course they're all inconsistent, even within the same make!
  • The types of attributes are in flux. I'd like to add others like Directivity Factor and Directivity Index, but I'm still learning on how to incorporate these.
  • Ideally this should become a database-driven web application, like Ricci's. In time I hope to trick co-workers into giving me some development time.


So this list is only a few months old. With help and suggestions and education it will get refined. I welcome lots of input!
mtbdudex is online now  
post #22 of 28 Old 07-31-2013, 03:19 AM
AVS Special Member
 
teckademic's Avatar
 
Join Date: Feb 2005
Location: san jose, ca
Posts: 1,887
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Liked: 53
I've always wondered about setting up reference levels as well. Right now, I have all my speakers and two subs calibrated at 80db and subs at 83db using the Disney WOW disc. I currently listen to almost all movies at -20 below reference, which is pretty loud, for me at least. Since I have everything calibrated to reference, does that mean that my subs are actually capable of being louder? I sometimes will turn the volume down thinking that i may damage the subs, but often I think I just underestimate my subs, which are SVS subs by the way. Is that why some people like to run their subs a bit hot since they are not able to achieve reference levels from their speakers?
teckademic is online now  
post #23 of 28 Old 07-31-2013, 07:31 AM
AVS Special Member
 
JHAz's Avatar
 
Join Date: Mar 2009
Posts: 4,099
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 143 Post(s)
Liked: 172
Quote:
Originally Posted by teckademic View Post

I've always wondered about setting up reference levels as well. Right now, I have all my speakers and two subs calibrated at 80db and subs at 83db using the Disney WOW disc. I currently listen to almost all movies at -20 below reference, which is pretty loud, for me at least. Since I have everything calibrated to reference, does that mean that my subs are actually capable of being louder? I sometimes will turn the volume down thinking that i may damage the subs, but often I think I just underestimate my subs, which are SVS subs by the way. Is that why some people like to run their subs a bit hot since they are not able to achieve reference levels from their speakers?

reference doesn't care how loud your subs or main speakers can actually play. If you listen around -20 dB, then turn up to reference, each sound theoretically would be reproduced 20 dB louder (100 times the power, subjectively around 4 times as loud. Whether your sub can play that loud without unacceptable levels of distortion or self destructing depends on the sub, which the receiver has no knowledge of. I listen at about the same levels, and my sub gets unhappy at higher SPLs. I also suspect that my small Paradigm speakers cannot accurately reproduce the loudest parts of movies at reference. I suspect they would be compressing (not getting as loud as the incoming signal would dictate) and likely distorting, too.
JHAz is offline  
post #24 of 28 Old 07-31-2013, 10:56 AM
AVS Special Member
 
Nyal Mellor's Avatar
 
Join Date: Aug 2010
Location: SF Bay Area, California, USA
Posts: 1,112
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 133 Post(s)
Liked: 98
There seems to be an error in the latest version of the 'reference speakers' list. The calculated formula is 3dB off what it should be. I posted about this on the thread but as yet I have not heard back from the thread and list owner.

Acoustic Frontiers: design and creation of high performance listening rooms, home theaters and project studios for discerning audio/video enthusiasts.
Nyal Mellor is offline  
post #25 of 28 Old 07-31-2013, 03:31 PM
AVS Special Member
 
mtbdudex's Avatar
 
Join Date: May 2007
Location: SE Michigan
Posts: 4,908
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 77 Post(s)
Liked: 349
Jhaz what paradigms are your front soundstage?
I've got their 2008 floor standing monitor 9 for R/L and cc390 for center.

OP, I used to have my floor standing about 30" face from front wall, however due to my laminate screen they need to be outside of that, so after measurements I get better response with them almost against the front wall

This follows the guide line don't have your speakers at same distance from walls if at all possible.


Sent from my 32GB iPhone4 using Tapatalk
mtbdudex is online now  
post #26 of 28 Old 07-31-2013, 06:04 PM
AVS Special Member
 
teckademic's Avatar
 
Join Date: Feb 2005
Location: san jose, ca
Posts: 1,887
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Liked: 53
Quote:
Originally Posted by JHAz View Post

reference doesn't care how loud your subs or main speakers can actually play. If you listen around -20 dB, then turn up to reference, each sound theoretically would be reproduced 20 dB louder (100 times the power, subjectively around 4 times as loud. Whether your sub can play that loud without unacceptable levels of distortion or self destructing depends on the sub, which the receiver has no knowledge of. I listen at about the same levels, and my sub gets unhappy at higher SPLs. I also suspect that my small Paradigm speakers cannot accurately reproduce the loudest parts of movies at reference. I suspect they would be compressing (not getting as loud as the incoming signal would dictate) and likely distorting, too.

I always thought that being able to play at reference levels meant your system, along with the room itself, was at the top of their game. With my listening levels averaging out at -20, my thought has always been that the room itself doesn't allow me to reach reference, so that's when acoustic treatments come into play.
teckademic is online now  
post #27 of 28 Old 08-01-2013, 09:01 AM
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,530
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 851 Post(s)
Liked: 1205
Quote:
Originally Posted by teckademic View Post

Quote:
Originally Posted by JHAz View Post

reference doesn't care how loud your subs or main speakers can actually play. If you listen around -20 dB, then turn up to reference, each sound theoretically would be reproduced 20 dB louder (100 times the power, subjectively around 4 times as loud. Whether your sub can play that loud without unacceptable levels of distortion or self destructing depends on the sub, which the receiver has no knowledge of. I listen at about the same levels, and my sub gets unhappy at higher SPLs. I also suspect that my small Paradigm speakers cannot accurately reproduce the loudest parts of movies at reference. I suspect they would be compressing (not getting as loud as the incoming signal would dictate) and likely distorting, too.

I always thought that being able to play at reference levels meant your system, along with the room itself, was at the top of their game.

No, but does indicate a fair level of competency.
Quote:
With my listening levels averaging out at -20, my thought has always been that the room itself doesn't allow me to reach reference, so that's when acoustic treatments come into play.

I have to admit that you've sprung a new one on me. I don't agree. The fact that your listening levels average out to be -20 means that your preferences are not for sound that is really loud. It has no bearing on acoustic treatments because the benefits of acoustic treatments accrue at all listening levels.

If you are saying that the acoustics of your room are so bad that you can't stand to listen to your system at anything even vaguely approaching reference levels, then I might agree with that. Rooms with good acoustics tend to more enjoyable at loud levels even though they remain enjoyable at lower levels.
Nethawk likes this.
arnyk is offline  
post #28 of 28 Old 08-01-2013, 02:16 PM
AVS Special Member
 
teckademic's Avatar
 
Join Date: Feb 2005
Location: san jose, ca
Posts: 1,887
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Liked: 53
Quote:
Originally Posted by arnyk View Post

No, but does indicate a fair level of competency.
I have to admit that you've sprung a new one on me. I don't agree. The fact that your listening levels average out to be -20 means that your preferences are not for sound that is really loud. It has no bearing on acoustic treatments because the benefits of acoustic treatments accrue at all listening levels.

If you are saying that the acoustics of your room are so bad that you can't stand to listen to your system at anything even vaguely approaching reference levels, then I might agree with that. Rooms with good acoustics tend to more enjoyable at loud levels even though they remain enjoyable at lower levels.

Well, before my listening levels were usually around -25 and since adding acoustic treatment and recalibrating, my listening levels have moved up between -20 and -18. Now, im not saying that i hear any distortion or anything if i go louder, but everything begins to just sound like a lot of noise rather than detailed. Adding acoustic treatment has allowed me to go louder without any harshness to the sound and still keeping things clear by adding just with a few bass traps and first reflection points treated. I always figured my system will get as good as it gets when im near reference. Being that my listening room is an unfortunate squared room, acoustic treatments have proven to be a necessity in going loud, yet remaining detailed.
teckademic is online now  
Reply Audio Theory, Setup, and Chat



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