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Official JBL Synthesis / Pro / Revel Home Theater Thread

749K views 6K replies 375 participants last post by  KCAV23 
#1 ·
In a desire to clean up separate JBL Pro / Consumer / Synthesis / Revel threads that contain a great deal of overlap, I am starting this thread to consolidate the discussion around certain speaker models. Lately there have been so many conversations about such speakers as the JBL M2, the LSR708, the SCL3s and 4s, plus the Revel Concerta2, Performa3 and Ultima2 speaker lines and how they all relate to each other. With all the separate threads it gets really hard to keep all the discussions and Q and A straight. A perfect example is the new JBL Synthesis SCL3 and 4, which are exclusive to Synthesis but share similarities with JBL Pro products like the M2 and LSR7 series (and, in fact, they can be mixed and matched). Another example is the Revel C763L in-ceiling speaker which is often combined with JBL Pro and Synthesis speakers for in-ceiling ATMOS use.

All of these products fall into what might be called "higher end" Harman. For this reason, I often end up cross-posting much of the same information into each separate thread. A duplication of effort for me, and an annoyance to others, yet I want to make sure that those interested are aware of ongoing discussions and comparisons. For example, the other day I posted our listening tests of the JBL M2, LSR708 and Revel F36, and I ended up placing it into three different threads so that everyone interested could read about it. We will be doing much the same with the Revel F208, SCL3 & 4 and the LSR708 sometime in the next week, and instead of plastering it all over the Forum, I am going to post the results here.

So, to be clear, for the most part this is where I will go to answer questions about JBL Synthesis, the JBL M2, LSR7 series, SCL series, and various Revel models that are comparable. I will definitely still check in on the other threads for product specific questions, but will probably refer others back here for comparative or system based discussions.

I hope this new thread helps those who are trying to integrate speakers from these various lines into a cohesive system, and to understand the differences between them!
 
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#2 ·
A hopefully informative first post in the thread - a clarification of what JBL Synthesis is, as opposed to JBL Pro and standard JBL Consumer:

The best way to think of Synthesis is that it is JBL Pro adapted to the home sized spaces. JBL Synthesis was originally designed for professionals in music and movie industries wanting a "Pro Grade" experience in their homes. Synthesis is sold as complete systems, so that Harman can be sure that any “Synthesis” system is fully calibrated and sounds great. Harman personnel design the systems with knowledge of how the components will work together, and they choose the right components for each installation.

All JBL Synthesis systems are calibrated utilizing Harman's “ARCOS” system, which provides state of-the-art room EQ, as well as Harman's exclusive “Sound Field Management” (SFM) and “Auto Curve Sum” (ACS). The SFM algorithm minimizes seat-to-seat variations at low frequencies, while SFM solves the challenge of achieving an ideal blend between the subwoofers and the main speakers. No other system is capable of providing a seamless transition from subs to main speakers, which is immediately audible.

JBL Synthesis dealers like ourselves also sell very high-end JBL models that were previously only really sold in Japan (such as the Everest and K2), along with the “studio monitors” that have long been sold in the consumer channel.

Much of the transducer technology has roots with JBL Pro, such as the breakthrough “D2” compression transducer and its derivatives, as well as the High Definition Imaging (HDI) horn used in the JBL Professional M2, and the new JBL Synthesis models. JBL Synthesis systems are designed for residential rooms—no matter how large—and are optimized for such rooms which are much smaller than the large theaters for which JBL Professional is famous. Therefore, JBL Synthesis truly represents the best of JBL Professional technologies, fully-optimized for residential spaces.

Many “professional” applications occur in smaller rooms, and JBL Synthesis is often found in such applications. For example, roughly 90% of Blu Ray discs are mastered using JBL Synthesis systems, with Revel C763L in-ceiling speakers used for height channels.

You will need to use all Synthesis products IF you want the system ultimately Synthesis certified, which includes JBL techs coming out to your home and personally calibrating your system. Once this is done, JBL will literally sign off on your system exceeding THX and SMPTE specs for accurate film and music reproduction.

Our own demo system is made up of many Synthesis products (mixed and matched with Revel), but since we don't have the Synthesis SDEC, it is not technically a Synthesis system - yet...
 
#20 ·
It's nice to have multiple threads. One thread may be discussing amplification, another room interactions, another Dr. Toole's work, another comparing two or three speaker models, and yet another with reports on newly purchased items. Only one or two threads could get very boring (personally to me). With multiple threads, a thread may be boing, but a week or so later it may have great insight into a subject, or be very entertaining.

@John Schuermann puts a lot of work into these threads and that is appreciated. John also has a good way of contributing to the discussions so that they can explore both positive and negative aspects of Harmon products and their use.
 
#26 ·
This might help - I don't intend on discussing JBL Pro products intended for commercial theaters, auditoriums, or PA applications. IMO, that discussion is better left to the Pro thread you mentioned earlier. My discussion of Pro is going to be limited to the models JBL themselves feel are appropriate for home theater sized spaces, which are the M2 and LSR708 / 705. That's exactly why they ended up as part of the JBL Synthesis lineup, which, as I mentioned above, is essentially Pro adapted for home sized spaces.

My other intention is to bring a bit of a spotlight to JBL Synthesis, as there don't seem to be any other threads that deal with these models. Synthesis speakers use much of the same Pro technologies but with an emphasis on getting good sound in a home theater sized space, (vs. an auditorium or concert venue, where sound propagates differently).
 
#7 ·
I don't know how to consolidate these threads, but there is no doubt there is a lot tying them together, which is why John often posts in 3 or 4 threads on some topics.

I think that at a minimum its a good thing to consolidate John's contributions. John has contributed a whole lot to the JBL/Synthesis/Revel knowledge base around here. So if you have a Synthesis/Revel/JBL comment or question, particularly on where these all intersect, then this would be the place to post it or find the answer.

I wish we could have a single owners thread like JTR, but that's possible because the JTR line is very homogenous. The Harman product lines are just too diverse to ever hope for that kind of consolidation.
 
#8 ·
Thanks Gooddoc!

Yeah, I've tried to think of how to most effectively do it, but other than what I've done here, I don't have a better idea. I will still monitor the other threads, but rather than posting my comparative novels in three or four different places, I will just post them here and link to them in the other threads.

BTW, AVS is going to move the M2 thread from "Industry News" to "Speakers." That should help, too, since many people who might be interested in these wouldn't think to look at the news thread.
 
#9 ·
Thanks Gooddoc!


BTW, AVS is going to move the M2 thread from "Industry News" to "Speakers." That should help, too, since many people who might be interested in these wouldn't think to look at the news thread.
Possible they could rename it JBL M2 Owner's Thread since that's why it's become..
 
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#18 ·
I've been curious about the "hierarchy" (roughly delineated by MSRP I suppose) of some of the JBL Synthesis floor standing speakers. My interest was piqued after hearing the K2 at the Newport show - really stunning.

Obviously the Everest is the flagship model, followed by the K2. You then have the S3900, S4700 and 4367 models.

Can you illuminate anything on the differences amongst those latter 3 and how they sort price-wise?
 
#29 ·
Here you go:

JBL Everest - List $37,500 each

3-Way Floor Standing Loudspeaker
• Two 15” (38.1 cm) woofers
• 4” (10.2 cm) pure-beryllium diaphragm for crystal-clear highs
• 1” (2.5 cm), pure-beryllium diaphragm for extreme highs
• Self-charged Crossover network; Provides more transparent
and detailed voicing with lower distortion (Class A Operation)
• Frequency Response 29Hz – 60kHz (half space); 45Hz – 60kHz
(anechoic)
• Recommended Amplifier Power: 500 watts
• Sensitivity (2.83V @ 1m) 96dB
Nominal Impedance 8 ohms; 5.0 ohms @ 80Hz; 3.0 ohms @
40kHz
• Dimensions (H x W x D): 43.7” x 38” x 18.5”
(110.9 cm x 96.5 cm x 47 cm)
• Weight: 313 lb (142.1 kg) / Shipping Weight:383 lb (173.9 kg)
• Rosewood (RW) Finish with textured carbon fiber baffle.

JBL K2 - List $22,000 each

3-Way Floor Standing Loudspeaker
• 15” (38.1 cm) woofer
• 4” (10.2 cm) Magnesium high-frequency
compression driver with Bi-Radial® horn
• 1” (2.5 cm) Beryllium ultrahigh-frequency
compression driver with Bi-Radial® horn
•Frequency Response 48Hz – 50 kHz
•Low Frequency Extension 33Hz
•Recommended Amplifier Power 500 Watts
•Sensitivity (2.83V @ 1m) 93dB
•Nominal Impedance 8 ohms, 7 ohms minimum at 100Hz, 4
ohms minimum at 40 kHz
• Dimensions (H x W x D): 47.3” x 22” x 13.8”
(120.1 cm x 55.9 cm x 35 cm)
• Weight: 182 lb (82.7 kg) /Shipping Weight: 192 lb (87.2 kg)
• Wood grain or black zebra wood (ZW) finish

JBL S4700 - List $7500 each ($750 each more for Black Gloss)

3-Way Floor Standing Loudspeaker
• 380mm (15”) pure pulp cone with treated cloth edge and
Differential Drive® (U.S. patent no. 5,748,760 and other patents
pending) neodymium motor assembly
• 1.8” (4.6 cm) Aqua-Plas-coated titanium diaphragm high
frequency compression driver with Bi-Radial® horn
• 0.75” (1.9 cm) Titanium diaphragm ultrahigh frequency compression
driver with Bi-Radial® horn
•Maximum recommended amplifier power: 300 watts RMS
•Frequency response: 38Hz – 40kHz (–6dB)
•Nominal impedance: 6 ohms
•Sensitivity: 94dB (2.83V/1m
• Dimensions (H x W x D): 42.1” x 19.7” x 14.6”
(106.8 cm x 50.0 cm x 37.1 cm)
• Weight: 120 lb (54.5 kg)
• Cherry wood finish

JBL S3900 - List $5000 each ($500 more each for Black Gloss)

3-Way Floor Standing Loudspeaker
• Two 10” (25 cm) pure-pulp cones with ferrite motor assemblies
• 1.8” (4.6 cm) compression driver with an Aquaplas-treated
pure-titanium diaphragm and neodymium motor assembly on
a SonoGlass® Bi-Radial horn
• .75” (1.9 cm) compression driver with a pure titanium
diaphragm and neodymium motor assembly on a SonoGlass
Bi-Radial horn
• Maximum recommended amplifier power: 250 watts
• Frequency response: 33Hz – 40kHz (–6dB)
• Nominal impedance: 6 ohms
• Sensitivity: 92dB (2.83V/1m)
• Dimensions (H x W x D): 39.4” x 14.6” x 14.5”
(100.1 cm x 37 cm x 36.8 cm)
• Weight: 86 lb (39 kg)
• Cherry wood finish

JBL 4367 - List $7500 each

2-way Floorstanding Loudspeaker
• Low-Frequency Transducer: 15” (380mm) 2216Nd-1 Differential
Drive® woofer
• Mid/High Frequency Transducer: 3” (75mm) D2430K dual
compression
• Maximum Recommended Amplifier Power: 300 watts RMS
• Frequency Response (-6DB): 30 Hz – 40 kHz
• Sensitivity (2.83V@1M): 94dB
• Nominal Impedance: 6 Ohm
• Crossover Frequencies: 700 Hz
• Enclosure Type: Bass-reflex via Dual Front-firing Ports
• Inputs: Dual Gold-plated Five-way Binding Posts
• Dimensions (H X W X D): 37-1/16” x 22-1/16” x 16-3/4”
(941mm x 560mm x 425mm)
• Weight: 135 lb (61.2 kg)
• Finishes: Walnut or Black Walnut Woodgrain Veneer

Hope that helps!
 
#21 ·
I am eagerly waiting for the Revel f208 and 708i comparison... I still have not decided to order the Crown/708i combo due to being afraid that the noise of the amp will be too much in my room.I have to have it in the living room.

I am thinking if its better to try the Revels or the JBL 4429 with suitable amp, maybe a bit more from money side but if they offer similiar/better performance than I can live with it.
 
#22 ·
Would it be okay to transport the M2's (still sealed in their box) on their side for a short 5-6 mile ride, as opposed to me renting a truck to carry them upright?

Thanks
 
#23 ·
Would it be okay to transport the M2's (still sealed in their box) on their side for a short 5-6 mile ride, as opposed to me renting a truck to carry them upright?
Delivery companies like FedEx / UPS wouldn't think twice about doing MUCH worse with them. I'd be shocked if they aren't packed well enough to survive such a trip and are most likely designed to handle somewhat more rough treatment than most speakers.
 
#25 ·
whichever method you chose to transport I would strap the boxes down so they arent bouncing around
 
#27 ·
I think a dedicated thread is not a bad idea, but too many threads could be confusing. It does seem like some of the Pro guys have a little animosity towards the more refined products so I can see the need for this thread. The Revel and Synthesis crowd gets somewhat excluded because the high cost of entry scares the majority or folks into a negative attitude so they don't understand or see value very well as the result. While some of the higher end Harman stuff does at times get pricey, I always looked at it from the point of view that generally speaking Harman stuff is a good value compared to the more esoteric options that cost more and perform worse. It's just the high cost is because it's actually pretty good, I feel like the cost is warranted by the refinement and quality rather the opposite point of view where the cost is unwarranted or the performance isn't up to par with the price. I can think of many examples in marketplace where the opposite exists so it's always been ironic to me so many view the high end Harman stuff like that. But I guess it's the interwebs so you get it all too. Revel and Synthesis isn't well represented in the current plethora of JBL threads IMO. The M2 is kind of like a bridge between PRO and synthesis so it's got a place in both conversations.
 
#31 ·
Exactly my thinking. To me, it's just a little weird that a speaker like the Revel Salon2 - which constantly wins double blind listening tests no matter what competing speaker gets thrown at it - could be considered "expensive" at $22K per pair when the speakers it gets pitted against during the double blinds can literally run up to 10 times that price. Then you've got the Revel F208, which possesses many of the same qualities of the Salon2s, at $5K per pair, well, to me the value proposition seems obvious. And now you have the Concerta2 F36 at $2K per pair. WOW, IMO. ;)

And that's just Revel. On the Synthesis side we have the Arrays, the M2s, the 708s, the SAM modules, the 4367 etc, which are still much less than some of the "high end" competition out there. I do understand the frustration some have with the amps and DSP required for the M2 and LSR708, but now we have speakers like the 4367 and SCL3 and 4 that DON'T have those requirements.
 
#39 · (Edited)
One issue with there being less chat about Synthesis has less to do with it self then the customers. Besides the DIY crowd that help them the whole build and are interested in it all, a lot of Sythesis system customers are the turn key customers that gets the system bought and doesn't know what half of it does, is for, or understands anymore then they desire. Not everyone just a hunch of mine.

I use JBL Pro cinema gear and I've lusted after JBL Synthesis systems for years and have always loved the approach. To me it represented what JBL learned in the comm theaters and refined it as you had said. The true magic lies in the EQ process/setup and that's hard to explain. They just need wowed in a demo. Speaking of wow Alcons Audio. They got the magic soup.

I think JBL is like Klipsch in a way to were its been around so long and so important to audio I don't think 10 threads would cover it all.
 
#41 ·
RE: your thoughts about who buys Synthesis systems. I think you are partly correct, which is a source of frustration for me. Synthesis represents what so many of us want - a finely tuned and accurate representation of what was intended by filmmakers and musicians - yet most home theater enthusiasts are not really aware of Synthesis at all. Yet many times these same enthusiasts will drop thousands and thousands of dollars on things that don't really matter - obscenely priced cables, power cords and line conditioners, for example. While a Synthesis SDEC and the accompanying calibration are not cheap, the cost can really pale in comparison to what someone can drop on the above mentioned items or on so called "high end" speakers that are really anything but! And, in the end, after calibration is done in your home (often by the same engineers who have just tuned a high end performance venue or mix stage), you have a system that is literally certified to exceed THX and SMPTE specs.
 
#42 ·
I agree that Harmon has some "special sauce" with room EQ and total presentation that is above and beyond a speakers measurement. It requires the complete package/presentation to work. However, I think Dirac Live narrows that secret sauce of Harmon down to almost trivial differences. The secret sauce is out and is more readily accessible. Dirac Live took my room to another level far and beyond what I anticipated. My room is also heavily treated with 3rd party analysis and products. Get a speaker that measures well, treat your room, and combine it with Dirac Live and the results are going to be close. Is Harmon better? I would have to hear it to believe it but for arguments sake, I will grant that. Is the difference worth the price delta? Only the buyer can decide.
 
#45 ·
Can't argue with your last four sentences :)

RE: Dirac Live, I haven't heard it so can't really comment from personal experience. I can tell you that Harman would strongly disagree, but you would expect that :) I'm calibrating with Audyssey Pro right now, so who am I to talk? The pros and cons of Audyssey have been well debated.

Here's a major difference between Synthesis / ARCOS / SFM calibration and other systems. With a Synthesis calibration, the ideal characteristics of each speaker are a known quantity that gets loaded into the ARCOS calibration software. In other words, the software *knows* what speakers you own and their specific characteristics. You actually load each speaker profile into the software - a trio of M2s, a set of 8 SCL4s, four JBL S2S-EX subs - and then ARCOS compares what is measured in your room with the actual data accumulated in Harman's test facilities. The difference is then EQ'd out, to the best of the software's ability. A Synthesis calibration takes an entire day, involves two technicians, and eight microphones placed in different locations. But. as you say, there is a corresponding cost.

With systems like Audyssey, ARC, and Dirac, the speaker models are not a known quantity, so at best such systems are shooting in the dark. If Audyssey, for example, decides that your main speakers need a boost of 4.5 db at a certain frequency, how does it know if your speaker is even capable of handling that boost? (In defense of Audyssey, it usually does far more cutting than boosting, knowing that this is a much safer approach).

Please know that I am not trying to bash other systems (or speakers, for that matter), but simply trying to illuminate what Synthesis is all about. Most people have no idea.
 
#43 ·
Does JBL synthesis technicians that come to calibrate/setup the system set up the FR to the way the buyer wants it...house curve...or do they do their best to make the FR flat. what are their goals when setting up the system for in room response?
 
#46 ·
Harman has there own target curves, based upon all the research that they have done over the decades. However, they can specify different targets based on preference, etc, plus set up different profiles for music, movies, different surround formats, etc.
 
#44 · (Edited)
The first of a couple of informational posts, this one about Harman's "Spinorama" speaker graphs and how to read them. Instead of just having a single line showing supposed "frequency response," the spins measure much more in the way of speaker performance - on and off axis frequency response, sound power response, listening window, etc.

Pay particular attention to a speakers' output far off-axis horizontally, since all the research that Harman has done demonstrates that those first reflections are of extreme importance in determining overall sound quality. More detailed info on this is in the Primer below the graphs, which is a must read!:

JBL M2:



JBL LSR708:



Revel F208:



JBL 4722n:




HARMAN Spin-o-rama Explanation

On-axis Response - This represents the direct sound heard by a single listener sitting on the design axis of the loudspeaker. A flat frequency response is an absolute requirement for all electronic devices. Therefore, it is not surprising that loudspeakers with a flat on-axis frequency response have a higher probability of being preferred in double-blind listening tests.

Listening Window - The well-designed loudspeaker should deliver good sound to a group of listeners -- not just the person sitting on-axis. The listening window is the average frequency response measured for listeners sitting on and slightly off the reference axis of the loudspeaker. Loudspeakers that receive high sound quality ratings in double-blind listening tests tend to have listening windows with a flat frequency response.

First, or Early Reflections -- Most of the sound we hear is reflected in rooms. The second loudest sound (after the direct sound) is the first reflected sound produced from the loudspeaker. Therefore, it is paramount that the sounds radiated by the loudspeaker in the off-axis directions generate early reflections that sound good. The shape of this curve should not differ greatly from the on-axis response curve.

Sound Power Response - This is a measure of the total sound radiated by the loudspeaker without regard to the direction in which it is radiated. The shape should be smooth and slightly downward tilting.

Sound Power and First Reflection Directivity Indices - These directivity indices tell us how the directivity of the loudspeaker changes as a function of frequency. At low frequencies most loudspeakers radiate sound omni-directionally (DI = 0 dB), where wavelengths are long. In forward-firing, 2-way and 3-way loudspeakers, as wavelengths get shorter, frequencies get higher, and more of the sound is radiated towards the front. The goal is to have this trend develop smoothly and gradually. These curves describe very good behavior.
 
#47 · (Edited)
RE: the graphs above. One of the things that confuses people about measurement graphs - especially when they see all kinds of little bumps, dips and ridges - is that there is no standardized reference for when comparing to other manufacturer speaker graphs (that's why I posted the "Primer" below the measurements). Harman is trying to correct for this with the new CEA 2034 speaker measurement standard, which should allow for a standardized speaker measurement system. Over the years, Harman has done so much research in relation to how a speaker measures in relation to listener preference that they can now predict which speakers will win double blind, scientifically controlled listening sessions - just based upon the spinorama measurements alone, and with 86% accuracy. Dr. Sean Olive discusses all of that here:

http://www.soundandvision.com/content/15-minutes-harmans-audio-guru-sean-olive#fSiFpSf7kTmVqquA.97

From the article: At Harman we can characterize and predict the sound quality of loudspeakers with 86 percent accuracy based on a set of comprehensive anechoic measurements. Our measurements are now the basis for a new ANSI/CEA 2034-A Standard: Method of Measurement of In-Home Loudspeakers so there is hope that eventually these will be adopted as standards for the industry.

I also thought I'd post a bit here about how comparing speaker measurement graphs can be so confusing:

The above speaker graphs are all high resolution, so appeared less uniform than other typical speaker FR graphs that typically apply 1/3 octave or greater smoothing. That is what most people are used to looking at.

The fact that JBL / Revel provide high resolution graphs to share shows that they are committed to high resolution measurements. But the fear in sharing them has to do with possible misinterpretation. If JBL used typical industry practices in this case, several of the lines above would be almost perfectly smooth.

Good article about this on Audioholics here, showing the effects of smoothing and resolution on frequency response graphs:

http://www.audioholics.com/loudspeaker-design/audio-measurements

Below are two graphs from the article, one with 1/12th octave smoothing, the second with 1/3 octave smoothing. These graphs are measurements taken of an RBH T30-SLE. The graphs I shared here had a 1/24th octave resolution, which is greater than even the "rougher" looking, 1/12 octave graph taken from the Audioholics article. I think everyone reading can see why context is all important when reading graphs:



 
#48 · (Edited)
Last of my "informational" posts for today - hopefully these are not too boring! This one about the "Audio Circle of Confusion" Drs. Toole and Olive talk so much about, which is a problem that Synthesis directly aims to address. Most of this information is from Sean Olive's blog post about this, which can be found here:

http://seanolive.blogspot.com/2009/10/audios-circle-of-confusion.html

A most excellent read, for someone wanting to really take the time to fully understand this.

First off, here is a picture of the measured room response of 250 identical high quality reference monitors but placed in 164 different control rooms. Theoretically, all the measurements should be the same since the speakers are the same - but they are not. The differences are due to the room itself. And keep in mind that these are professional audio control rooms, with acoustic treatments, optimized room designs, etc:



All of this leads to the dreaded Audio Circle of Confusion:



Since mix engineers cannot rely upon their mix environments to be perfectly flat and accurate, how can they expect their mixes to be perfectly flat and accurate? And, since they are also evaluating their own setups based on mixes created in OTHER mix environments - which will have problems of their own - how can they trust the recordings created by others when they are using them to check their own systems and mixes?

This is exactly the kind of research Harman does - to try to equalize all of these elements out so that one room will "sound" like another. And this research is what has led to the creation of ARCOS, SFM, and other technologies (as well as speakers such as the M2, 708, etc). In addition, it was research into solving the bass issues - which is where most of the problems lie in the graphs above - that led to the multiple subwoofer solution that the engineers at Harman developed (referenced in depth in the Floyd Toole article I mentioned above - here it is again for ease of access: http://www.audioholics.com/room-acoustics/history-of-multi-sub-sfm).

All of these things converge in Synthesis, and why a Synthesis system is used for final Blu-ray mastering in most cases.

One of the things that you find with extremely accurate speakers like those from Revel and JBL is that deficits in the original recording are laid bare. If the recording was mixed on bass heavy speakers (or in a bass heavy room), the recording engineer may have rolled off the bass in the recording to compensate. Now what we have is a "bass-shy" recording. Often just the opposite is true. As Sean Olive says, the recording itself becomes the "nuisance variable" in the equation. As I've stated elsewhere, IMO this is not an argument for less accurate speakers, it becomes an argument for better quality recordings.

So, by trying to solve this Circle of Confusion, Harman is working hard to take these variables out of the recording and mastering process so that we can all benefit. Good sounding recordings will sound best on the widest variety of speakers, but best on the most accurate speakers.

Here is essentially the majority of Sean's article:

Audio’s “Circle of Confusion” is a term coined by Floyd Toole that describes the confusion that exists within the audio recording and reproduction chain due to the lack of a standardized, calibrated monitoring environment. Today, the circle of confusion remains the single largest obstacle in advancing the quality of audio recording and reproduction.

The circle of confusion is graphically illustrated in (the illustration above). Music recordings are made with (1) microphones that are selected, processed, and mixed by (2) listening through professional loudspeakers, which are designed by (3) listening to recordings, which are (1) made with microphones that are selected, processed, and mixed by (2) listening through professional monitors...... you get the idea. Both the creation of the art (the recording) and its reproduction (the loudspeakers and room) are trapped in an interdependent circular relationship where the quality of one is dependent on the quality of the other. Since the playback chain and room through which recordings are monitored are not standardized, the quality of recordings remains highly variable.

A random sampling of ones own music library will quickly confirm the variation in sound quality that exists among different music recordings. Apart from audible differences in dynamic range, spatial imagery, and noise and distortion, the spectral balance of recordings can vary dramatically in terms of their brightness and particularly, the quality and quantity of bass...

The most likely culprits are the loudspeakers and rooms through which the recording were made. While there are many excellent professional near-field monitors in the marketplace today, there are no industry guidelines or standards to ensure that they are used. The lack of meaningful, perceptually relevant loudspeaker specifications makes the excellent loudspeakers difficult to identify and separate from the truly mediocre ones. To make matters worse, some misguided recording engineers monitor and tweak their recordings through low-fidelity loudspeakers thinking that this represents what the average consumer will hear. Since loudspeakers can be mediocre in an infinite number of ways, this practice only guarantees that quality of the recording will be compromised when heard through good loudspeakers...

Another significant source of variation in the recording process stems from acoustical interactions between the loudspeaker and the listening room. Below 300-500 Hz, the placement of the loudspeaker-listener can cause >18 dB variations in the in-room response due to room resonances and placing the loudspeaker in proximity to a room boundary....Below 100 Hz, the in-room bass response can vary as much 25 dB among the different control rooms! You needn’t look any further than here to understand why the quality and quantity of bass is so variable among the recordings in your music library.

Loudspeaker manufacturers are also trapped in the circle of confusion since music recordings are used by listening panels, audio reviewers, and consumers to ultimately judge the sound quality of the loudspeaker. The problem is that distortions in the recording cannot be easily separated from those produced by the loudspeaker. For example, a recording that is too bright can make a dull loudspeaker sound good, and an accurate loudspeaker sound too bright...Through 25+ years of well-controlled loudspeaker listening tests, scientists have identified the important loudspeaker parameters related to good sound, which can be quantified in a set of acoustical measurement...By applying some statistics to these measurements, listeners’ loudspeaker preferences can be predicted...Good bass is essential to our enjoyment of music, which unfortunately is a frequency range where loudspeakers and rooms are most variable...Controlling the behavior of loudspeakers and rooms at low frequencies is essential to achieving a more consistent quality of audio recording and reproduction. Fortunately, there are technology solutions today that provide effective control of acoustical interactions between the loudspeaker and rooms...the key in breaking the circle of confusion lies in the hands of the professional audio industry where the art is created. A meaningful standard that defined the quality and calibration of the loudspeaker and room would improve the quality and consistency of recordings. The same standard could then be applied to the playback of the recording in the consumer’s home or automobile. Finally, consumers would be able to hear the music as the artist intended.
 
#53 ·
I want to cross-post and re-post something I post in the the other M2 thread. It bolsters what John is talking about but may have made no sense without my further explaining it...

"Here's an interesting story... When Bob Hodas finished tuning my room years ago, my NS10's and ADAM S5A's sounded darn near identical. We would get confused on which set we were actually mixing on at times. The 10's were on the meter bridge, and the S5's on huge stands behind the console. So they were completely different setups in other words. You could shut your eyes and switch between them and literally lose track. When Carl Tatz did his Phantom Focus System in the same room a couple of years ago, the same thing happened, except the speakers were the S5A's and Dynaudio M1's. Once again, you could get confused about which set you were on at any given moment. This was even in spite the S5's were big ribbon drivers. When you get setup and response right in a room using good speakers, the results will often end up the same despite brand name/driver differences.... Both of these guys spent hours laser aligning things exactly right. It was very cool..."


So my point of originally posting this was to point out that measurements from the speakers themselves are only one part of the equation. The room in and of itself is really another speaker. Failure to integrate further downline pretty much renders the original lab grade measurements worthless as displayed in several of John's posts above. Does this mean original measurements aren't important? No, it simply means that a well designed speaker deserves a well designed, and properly implemented room to put them in. Then they need to be tuned and integrated to match. In the end, if done properly, those properly integrated and well designed speakers, even of different brands and/or types, will behave very similarly to each other. It blew my mind when Bob got done. We literally couldn't tell the difference at times from which set of monitors we were on. And of course our mixes ended up translating much better to the outside world (the point of doing this in the first place) which helped to break the "Circle of Confusion". Of course the mastering engineer next in line could likely butcher everything you did do to "Loudness Wars". That's why you always attend mastering sessions if at all possible.
 
#54 · (Edited)
Really great stuff John. Real great. The kind of stuff my audio geeks sit around and ponder so to speak. Great audio is like fine dining. Most wouldn't notice or appreciate it or are educated enough to know it. A guy with the fresh caught trout diner enjoys it just as much as another guy loving his Big Mac. First gentlemen thinks of it swimming and living in a wonderful stream, and how thru all that this perfect dish is the end result after the fisher and fillet guy and chef worked in unison. The Big Mac guy liked how there was two drive thru lines Most of my non audio friends think this way. I'm wasting time and money on something silly like a stereo. Its all perspective mostly. What your doing is fantastic tho for the industry. It's the public that scares the crap out of me. Most just don't care. Not all but some
 
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