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JBL 4349 Review (Studio Monitor Speaker)

More Dynamics Please

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This seems an appropriate point to invoke select quotes from an interview with Greg Timbers, the highly regarded retired JBL designer/engineer. The whole interview is well worth reading for all who are interested in how a dynamic speaker can overcome imperfect measurements to create an enjoyable listening experience:

I am a dynamics guy and very few loudspeakers take that into consideration, in my opinion. Two Engineers that I do admire are Bill Decanio and Charles Sprinkle.

Like everybody else, I look (listen) for what makes me forget that I am listening to sound reproduction. In my opinion, it is necessary to have an acceptable degree of frequency and power response accuracy. I do not feel that these measurements need to be perfect. For me, Dynamics will make or break the loudspeaker system. Live music is dynamic as hell and this is one of the most difficult attributes to reproduce. Compression exists at all stages of the reproductive and recording chain. Of course, loudspeakers have the most but it is apparent in electronics as well.

I believe that solid Dynamic behavior is most important to get lifelike sound. Dynamics require high efficiency since transducers are pitiful in energy conversion. I also believe that sound staging is extremely important. I think natural midrange and bass presentation precedes the treble range. Of course all things have to be balanced!

Speakers have generally become smoother, more 3-dimensional and much smaller. This means that they are less dynamic on the whole and rather toy like compared to good stuff from the 60s and 70s. Unlike electronics, miniaturization is not a good thing with loudspeakers. There is no substitute for size and horsepower. Nothing much has changed with the laws of physics in the last 100 years so what it takes to make dynamic life-like sound is unchanged.


https://positive-feedback.com/interviews/greg-timbers-jbl/
 

Robbo99999

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And sound like a cheap plastic toy if directly compared;)
It might depend on what volume you decide to play them at, but I certainly won't be buying the speakers in this review anyway....I don't think I'll be buying speakers to replace my 308's in a long time, I might get some subs to go with them, but otherwise I'm good.
 

Easternlethal

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This seems an appropriate point to invoke select quotes from an interview with Greg Timbers, the highly regarded retired JBL designer/engineer. The whole interview is well worth reading for all who are interested in how a dynamic speaker can overcome imperfect measurements to create an enjoyable listening experience:

I am a dynamics guy and very few loudspeakers take that into consideration, in my opinion. Two Engineers that I do admire are Bill Decanio and Charles Sprinkle.

Like everybody else, I look (listen) for what makes me forget that I am listening to sound reproduction. In my opinion, it is necessary to have an acceptable degree of frequency and power response accuracy. I do not feel that these measurements need to be perfect. For me, Dynamics will make or break the loudspeaker system. Live music is dynamic as hell and this is one of the most difficult attributes to reproduce. Compression exists at all stages of the reproductive and recording chain. Of course, loudspeakers have the most but it is apparent in electronics as well.

I believe that solid Dynamic behavior is most important to get lifelike sound. Dynamics require high efficiency since transducers are pitiful in energy conversion. I also believe that sound staging is extremely important. I think natural midrange and bass presentation precedes the treble range. Of course all things have to be balanced!

Speakers have generally become smoother, more 3-dimensional and much smaller. This means that they are less dynamic on the whole and rather toy like compared to good stuff from the 60s and 70s. Unlike electronics, miniaturization is not a good thing with loudspeakers. There is no substitute for size and horsepower. Nothing much has changed with the laws of physics in the last 100 years so what it takes to make dynamic life-like sound is unchanged.

https://positive-feedback.com/interviews/greg-timbers-jbl/
In other words: Screw psychoacoustics because a big ass speaker with good components will beat a smaller one everytime..

My kinda guy
 

dfuller

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This seems an appropriate point to invoke select quotes from an interview with Greg Timbers, the highly regarded retired JBL designer/engineer. The whole interview is well worth reading for all who are interested in how a dynamic speaker can overcome imperfect measurements to create an enjoyable listening experience:

I am a dynamics guy and very few loudspeakers take that into consideration, in my opinion. Two Engineers that I do admire are Bill Decanio and Charles Sprinkle.

Like everybody else, I look (listen) for what makes me forget that I am listening to sound reproduction. In my opinion, it is necessary to have an acceptable degree of frequency and power response accuracy. I do not feel that these measurements need to be perfect. For me, Dynamics will make or break the loudspeaker system. Live music is dynamic as hell and this is one of the most difficult attributes to reproduce. Compression exists at all stages of the reproductive and recording chain. Of course, loudspeakers have the most but it is apparent in electronics as well.

I believe that solid Dynamic behavior is most important to get lifelike sound. Dynamics require high efficiency since transducers are pitiful in energy conversion. I also believe that sound staging is extremely important. I think natural midrange and bass presentation precedes the treble range. Of course all things have to be balanced!

Speakers have generally become smoother, more 3-dimensional and much smaller. This means that they are less dynamic on the whole and rather toy like compared to good stuff from the 60s and 70s. Unlike electronics, miniaturization is not a good thing with loudspeakers. There is no substitute for size and horsepower. Nothing much has changed with the laws of physics in the last 100 years so what it takes to make dynamic life-like sound is unchanged.

https://positive-feedback.com/interviews/greg-timbers-jbl/
I have to say there really is something to a speaker with good LF dynamic response. I think that's part of why I like the sound of very long throw drivers in a sealed box with tons of amp (or a very high sensitivity driver) over a shorter throw and a lot of bass reflex to reinforce it and less amp. Maybe it's not as low distortion at LF but at the same time there's literally no replacement for displacement (especially when there isn't any sort of janky bad port tuning bass overhang).
 
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Andrej

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I have to say there really is something to a speaker with good LF dynamic response. I think that's part of why I like the sound of very long throw drivers in a sealed box with tons of amp (or a very high sensitivity driver over a shorter throw and a lot of bass reflex to reinforce it and less amp. Maybe it's not as low distortion at LF but at the same time there's literally no replacement for displacement (especially when there isn't any sort of janky bad port tuning bass overhang).
I have come to exactly the opposite conclusion using the same information:).
My preference is for low moving mass drivers - not just the physics (mechanics) of it, but to me they sound more life-like, and they obviously need less force to keep under control. The caveat being that making them lighter does not make them more prone to breakups, or at least keeps it well out of the operating range. In addition, for deep bass, human perception is much less sensitive to "deviations from perfection" that adding a vent only helps. At the frequency range covered by the same driver in a closed box nothing much changes, but the vent can give you decent output for more than another half octave, which I want, need! to have:). Both distortion and displacement requirements go way down, allowing for lower x-max and lighter moving mass, both of which I desire. My feeling (no data to support it:)) is that commercial products do not make vented enclosures big enough for living room size bass augmentation, and significant room resonances. Also, my observation is primarily about deep bass (20-40Hz).
There is always more than one way to skin this cat!-)

On a different but related topic, as a vented box being a Helmhotz resonator is by it's nature a resonance, when equalizing frequency response the most common practice is to tame resonances by parametric equalization bringing the response to be equal to the rest of the frequency range. I personally drop it further, until the resonance, which keeps ringing, and ringing, and ringing... disappears from the waterfall plot. Frequency response is instantaneous, but neither our hearing, nor the music we listen to, are.
 
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beagleman

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In other words: Screw psychoacoustics because a big ass speaker with good components will beat a smaller one everytime..

My kinda guy


But is this not really Apples versus Oranges?

Huge ass speakers almost always cost Far more, cost more to build and to ship.

If they cost the same, a huge and small speaker, then maybe, but you are kinda saying a Tri Axle dump truck, beats a pickup truck for hauling every time.....lol
 

Duke

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As a side note. I hardly ever come home from a show thinking of replacing my speakers with anything I see there. The only exception was a set of large horn speakers that had dynamics that I could not replicate with my Salon 2s. The 4349 allowed me to get there and so points to high efficiency mattering. People routinely underestimate how much power it takes to reproduce dynamics well. Even my high power amplifier struggles to push the Salon 2 there. But with 4349, that struggle disappeared with a bunch of headroom left.

I am going to put the JBL 4349 on my recommended list. Go ahead and hate on me due to objective measurements above. I am ready to take it!

What a fascinating test and what an educational set of conclusions! Amir I believe everything you say you heard from the 4349's.

The implications are potentially boundary-pushing for anyone who believes the spins are all that really matter (and I say this as someone who has been using spins since 2005 and who sees them as his primary tool).

Dynamic contrast does not show up in any of the spin data and is at best only indirectly suggested by the distortion data. I had an interesting (and all-too-brief) conversation with Floyd Toole on another forum which included the subject of rapid-onset power compression due to voice coil heating , and he had this to say:

"The audibility of power compression in its many variations probably could use some more research to define what is audible and what is tolerable. The magnet heating that you describe is important in pro audio sound reinforcement systems where the loudspeakers are required to work at or close to their design limits for long periods. Such heating and cooling has a very long time constant. This is not the case in most home systems. Although the modification of motor strength through magnet heating is a factor, most of the audible effects are from voice coil heating, which has a much shorter time constant. I just saw a test of a high-end audiophile speaker that in going from an average level of 70 dB (loud conversation, background music) to 90 dB (a moderate crescendo, or foreground rock listening) lost about 4 dB in output over about 3 octaves in the mid-high-frequency range. It became a different loudspeaker at different listening levels." [emphasis Duke's]

The thermal modulation characteristics of the loudspeaker drivers are arguably a significant piece of the puzzle, if we care about sound quality. Musicians use dynamic contrast to convey emotion, so when dynamic contrast is lost, so is some of the emotion; on the other hand when dynamic contrast is preserved, likewise more of the emotion is preserved. @amirm, does that make sense to you?

Years ago Stereophile did an article which supposedly "debunked" the "myth" of thermal modulation. Their measurement procedure was flawed in that they did not sample the voice coil temperature at the instant of peak power, but rather they sampled voice coil temperature at regular time intervals and then averaged the results. So whatever was happening specifically at the peaks was not captured. Unfortunately the article's conclusion - that thermal effects are negligible in home audio - became part of mainstream audio folklore, and imo continues to show up even on this forum. How convenient it would be if everything that matters to the ears could be delivered by good minispeakers and a sub plus a bit of EQ!! Note that it was only a few heretical high-efficiency aficionados who rejected Stereophiles findings, and few of them were nerd enough to critique the test procedure itself.

Anyway I applaud Amir for NOT ONLY his thorough testing BUT ALSO his thorough listening evaluation, which in this case revealed something significant that was not obvious from the measurements he made.
 
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amirm

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@amirm, does that make sense to you?
It does at some level but I just don't have the experience or knowledge of the research (if any) to know what the impact really is. Andrew Jones was tracing a resonance issue I had found in one of his speakers and he reported incredible rise in temp: https://www.audiosciencereview.com/...-0-review-bookshelf-speaker.19216/post-690938

After a short while I went to push on the midrange cone to see if it might be rubbing on a potentially off-center tweeter, but was surprised that the midrange cone was very hot. The midrange driver has a voice coil wound on an aluminum former bonded to an aluminum cone. This gives quite a good heat transfer from coil to cone.

He was pushing it hard but still, there is a lot of energy is being lost in these drivers.
 

sarumbear

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In other words: Screw psychoacoustics because a big ass speaker with good components will beat a smaller one everytime.
That is psychoacoustics!
 

JohnBooty

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Musicians use dynamic contrast to convey emotion, so when dynamic contrast is lost, so is some of the emotion; on the other hand when dynamic contrast is preserved, likewise more of the emotion is preserved. @amirm does that make sense to you?

I think this is super uncontroversial! When you listen to two versions of the same recording, one of which has had the dynamic range smashed out of it ala "loudness wars" mastering, the difference is usually quite striking. Much has been written about the "loudness wars" in modern music releases, and how bad it makes things sound bad.

The thermal modulation characteristics of the loudspeaker drivers are arguably a significant piece of the puzzle, if we care about sound quality.

It may be thermal modulation and it may be a combination of other factors. I personally would be thinking less about thermal modulation in particular and more about how the speakers perform at high SPLs in general. Whatever the causes, it's the measured change (or lack of change) in THD from 86dB to 96dB that really tells the story right?

All in all I'm glad to see a growing awareness of this in objectivist circles. I feel like the ability of a system to reproduce dynamic peaks has often been laughed at by a lot of objectivists, which was always rather frustrating since to me it was always something real and measurable, not "audiophool" stuff.
 

Duke

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It may be thermal modulation and it may be a combination of other factors. I personally would be thinking less about thermal modulation in particular and more about how the speakers perform at high SPLs in general. Whatever the causes, it's the measured change (or lack of change) in THD from 86dB to 96dB that really tells the story right?

My understanding is that there are four primary mechanisms (two thermal, two mechanical) by which power compression may occur:

1. Rapid-onset voice coil heating which causes the voice coil resistance to rise;

2. Slow-onset magnet heating which causes the magnet to temporarily lose strength;

3. Voice coil excursion beyond its linear limits; and

4. Suspension system excursion beyond its linear limits.

[edit: @Kvalsvoll pointed out another source of power compression which I overlooked: Nonlinearities in the motor induced by current in the voice coil.]

I can see how the two mechanical compression mechanisms would show up in distortion measurements because they change how the cone moves over some of its travel, but it is not clear to me how the two thermal compression mechanisms would show up in distortion measurements. [The flux modulation and induction nonlinearities Kvalsvoll mentioned WOULD show up in the distortion measurements.]

So I do not think that power compression can be adequately evaluated from distortion measurements. I think it would need to be measured directly, then those findings would need to be correlated with perception, and I don't think that has been really been done yet.

One of the more insidious issues thermal modulation can give rise to is described in the Floyd Toole quote in my previous post. To paraphrase, if the different drivers in a speaker system have significantly different thermal compression characteristics, then the system's tonal balance can change with power level.

In general the two best predictors of thermal compression are probably driver efficiency and voice coil mass (driver thermal power handling ratings have grown in recent years as high-melting-point formers and glues are being used in the voice coils to forestall deformation, but this does not mitigate thermal compression). X-max is probably a good predictor of the onset of significant mechanical compression, as x-max may be established either by the voice coil's linear excursion limits or the suspension system's linear excursion limits.
 
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Dave Tremblay

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I suspect it would be difficult to trace limits in dynamics to a single THD test. Although that certainly presents a reasonable picture (86dB to 96dB, for example), with musical signals it is likely much more complicated...

One thing you'll notice in most of these speaker tests is that distortion rises dramatically in the lower frequencies. Most music we listen to has a "pink" characteristic, meaning that it has a lot more bass than midrange and highs. The lower frequencies are dominating the average and peak SPL levels. The problem here is that these higher level signals move the cone out towards its excursion limits. If this same driver is trying to play a signal up at 1kHz, the distortion in this cone position will be WAY worse. Likely presenting as increased THD over what is in the graphs at 1kHz, but also as IMD.

When I look at those graphs, I look at the range where individual drivers are covering and assume the worst case distortion across that whole spectrum. If a small 4" woofer is at .5% distortion at 2kHz, but at 10% distortion at 100Hz, I generally assume that in reality, you're going to hear more like that 10% distortion even at 1kHz. I don't have data to back this up, just intuition based on the distortion mechanisms (BL, Suspension, etc). In my opinion, this is likely a bigger deal than thermal variations, but I'm very open to someone teaching me this is not the case.

All of the above is why I tend to prefer 3-way speakers. Let the woofer, below 200Hz, distort, but don't add distortion to the midrange based on that bass content. And in a 2-way, I like large drivers to keep cone motion lower at my preferred listening levels (82-85dB Average, 108dB Peak), thus not trying to play the midrange on a cone that is near max excursion. But if you use large drivers, you need to have low crossover points.
 

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This is an absolutely wild thing to say.

When we speak of those things, we're talking about an objectively and repeatably measured property of the speakers. It's the literal opposite of audiophool talk.

I had to edit this post for civility several times before hitting "Post reply" because wow, that's just an unbelievable statement.

Not sure what you're in a huff about, he's right. Audiophiles get shit talked relentlessly on ASR for the same kind of thing that's happening in the OP. Their subjective experience is routinely dismissed in favor of objective measurements. This review is a rare role reversal, so I'm not surprised to see people calling it out.

I prefer ASR to AudioGon and other subjectivity paradises, but sometimes you gotta call a spade a spade.
 

Duke

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Is there a highly efficient horn system that measures with the best?

GedLee Summa

SummaGraphs.jpg
 

Newman

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That should be ‘was’, not ‘is’, for Gedlee speakers. And is 97 dB a really high efficiency? Only 6 more than 91 dB, so 1/4 power.
 

DualTriode

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These large professional drivers; are rated at 600 watts JBL 2226 to 2235 recone (woofers) and 250 watts for a JBL 2123 mid driver.

Operating at 5 watts in your home the police will be pounding on your door. At 2 or 3 volts I am wearing 3M earplugs to test them.

There is near zero thermal compression with these pro drivers, at least the way that I use them.

Thanks DT

https://jblpro.com/en-US/site_elements/2226h-j-specification-sheet

Check the power compression data
 

Newman

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... from an interview with Greg Timbers,

Speakers have generally become smoother, more 3-dimensional and much smaller. This means that they are less dynamic on the whole and rather toy like compared to good stuff from the 60s and 70s. Unlike electronics, miniaturization is not a good thing with loudspeakers. There is no substitute for size and horsepower. Nothing much has changed with the laws of physics in the last 100 years so what it takes to make dynamic life-like sound is unchanged.

https://positive-feedback.com/interviews/greg-timbers-jbl/

And to put that in perspective, a home theatre sat-sub with 4 subs is NOT a small speaker. Compared to such a setup it’s the 4349 that’s the small speaker!
 

Newman

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What a fascinating test and what an educational set of conclusions! Amir I believe everything you say you heard from the 4349's.....

Why? On what rational basis? Or is it just because you like the conclusion?

...Anyway I applaud Amir for NOT ONLY his thorough testing BUT ALSO his thorough listening evaluation, which in this case revealed something significant that was not obvious from the measurements he made.

The only rational way to do a “thorough listening evaluation” which “reveals something significant” is... wait for it... blind tests. Since that didn’t happen here, it is rational to conclude it is far more likely that non-sonic factors are dominating the listening evaluation. Because they always do when given a chance. And that’s not up for discussion: it’s a proven fact.

Like Amir replied to me yesterday, we have been over this turf a million times. And apparently, according to Amir, I don’t have to read his listening reports. But I don’t know if that means I am expected to bite my lip while readers of his reports, such as yourself, focus on the scientifically-invalid part of his report and declare it “educational, thorough and revealing”.

I guess this post can be filed under ‘inconvenient truths to be swept under the rug in the rush to believe whatever reinforces our prior beliefs’. So be it.

cheers
 
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