JBL 708P Review (Professional Monitor)

[richard12511]

Does the 708P gets much louder than Genelec 8050b?
How do they compare in general?

Specs say the 708p gets 2dB louder. I'm guessing the 8050b will probably measure a bit better, but that's tbd.

 

[richard12511]

Since we are talking about SPL, would you guys say the 708i/708P (crossed over with subwoofers at 80 Hz or higher) will be able to provide "all the SPL that you might need" in a small room (for movies and music) where the listening distance is around 7 ft? Room size is about 12 ft long x 11 ft wide x 9.5 ft high. Note that this is for someone who listens really loud.

I would say yes, definitely.

 

[Aaron Garrett]

Yes this is interesting, there really seem to be two groups, one will prefer speakers, the other one headphones. I'm leaning to the latter, maybe because i'm using headphones since early childhood (different early conditioning of hearing?). An exception is (so far) surround sound.

I agree. I like headphones fine on music made for headphones, IDM for example, but I can only enjoy symphonic music on speakers and only if there is a lot of dynamic ability with little distortion.

 

[DSJR]

All thist alk of playing at 90dB+ levels... You lot don't know how darned lucky you are. Headphones only for me since early December and won't get a chance to play the boxes until early March

 

[q3cpma]

If you add a sub(or two) at 80hrz and high pass the monitor, you now have a pretty capable 3-way don't you?
Not to mention, that room is tiny by the way.

What I am really interested in why you are so discouraged about the Harmonic distortion levels? What is that you are looking for and why? So many folks pilling on this on this thread on the HD. Doesn't seem to correlate with my experiences, nor anything I have ever read that is suitable to quote here. So what gives?

My main beef is with the "high" H3 around 200-300 Hz, H2 around crossover point (yes, even when considering masking) and maybe the rising H5 at ~150 Hz.
I mean, compared to the way cheaper and smaller 8030C (whose LF problems would mainly be solved by the sub), this is quite ugly. Even if 1% really isn't that bad (probably just above the sine masking values).

IMD can not be inferred, it is a different measurement with a multitude of factors that would affect it.

Sure, but I've yet to find a 2-way that's no massively worse in that respect than any decent 3-way.

 

[respice finem]

I agree. I like headphones fine on music made for headphones, IDM for example, but I can only enjoy symphonic music on speakers and only if there is a lot of dynamic ability with little distortion.

For me it's better with headphones in most cases, but that (apart from my mentioned "conditioning") may be due to my rather mediocre listening room. I'm planning to move when I can afford to retire, but this will take more time than I thought. When I've arrived at this point, I can finally have a dedicated listening room for stereo, that would not deteriorate the sound (and hopefully I'll then still hear well enough to appreciate the difference). For now, the ability to have crossfeed when needed helps a bit (and/or the angled arrangement of drivers in my BD T1 Mk2), and with not-so-big classical (and jazz) ensembles, tonality and detail matters more (for me) than soundstage.

 

[Bugal1998]

Since we are talking about SPL, would you guys say the 708i/708P (crossed over with subwoofers at 80 Hz or higher) will be able to provide "all the SPL that you might need" in a small room (for movies and music) where the listening distance is around 7 ft? Room size is about 12 ft long x 11 ft wide x 9.5 ft high. Note that this is for someone who listens really loud.

"Really loud" is hard to address without specific spl requirements. But unless you're inviting hearing damage, in my experience I would say, yes. That's what they're designed to do. Also, the - 20db movie reference level in a room that size should be closer to 76db vs the 85db level used in auditorium sized spaces, which would free up plenty of headroom.

Between the lower average playback level required in a small room and the reduced spl attenuation with distance in your space, you should have plenty of output. 96db peaks would be rare anyway, and still within the speaker's llinear output even if distortion is starting to creep-up a bit.

I'd personally have no reservations about output in your scenario unless you're risking your hearing.

 

[JimWeir]

Just a note - a couple of years ago JBL released a new version of the L100 - -prices at the same point as the 708P's - to me no brainer to go with the 708's - built in Amps cave a kilobuck or two as well.

 

[Juhazi]

Lots of comments with "spl measured"... was that with A, C or Z weighting?

dB(A) is typical measurement for work environment, car interior etc. but I prefer C weighting to evaluate music sound pressure.
There are many freeware phone apps for spl measurement, nice to check live event levels!

 

[ROOSKIE]

My main beef is with the "high" H3 around 200-300 Hz, H2 around crossover point (yes, even when considering masking) and maybe the rising H5 at ~150 Hz.
I mean, compared to the way cheaper and smaller 8030C (whose LF problems would mainly be solved by the sub), this is quite ugly. Even if 1% really isn't that bad (probably just above the sine masking values).

Sure, but I've yet to find a 2-way that's no massively worse in that respect than any decent 3-way.

Without question, Genelec makes truly superb speakers.
They also have a knack for ultra low harmonic distortion levels. I really feel that that spec is important, yet as long as it is not broken, it is more of a mental game than a reality. Turn your attention toward Port velocity, which is ONLY a problem once it is overloaded and once overload is suppressed any attempt to lower it further has no practical effect. I suspect HD is similar. While this varies with frequency and order, is really not the issue we make of it. Trouble is it is REALLY easy to measure it so nearly any reviewer using measurements is going to do just that, so now we see it all the time and get used to thinking (over thing?) about it more than it is worth. (Stereophile magazine, interestingly doesn't use HD testing in their reviews, which feature some nice comprehensive measurements)

Here are a few screenshots from here at ASR of HD testing.
One thing is look at how low that $300 pair, JBL A130 is - especially that 5" woofer, right? Crazy.
That Genelec 8030c is very overloaded in the bass and midbass at 96db and that is likely to get MUCH worse fast trying to go higher, at 86 it is truly spectacular.
I threw in the ELAC 3 way as an example of how a 3 way is not always a HD/(IMD?) solution.
The Purifi woofer is "state of the art and world class and EXPENSIVE" and yet you can see how the JBl woofer has better HD levels. I am not saying that the Purifi is bad, just that maybe HD testing is not really a prime indicator as this woofer so far has been highly reviewed elsewhere.

If you or any reader passing by this post, are not already a fan/reader. I like to read the driver tests at these two sites for general info. The sites testing can not be compared against each other, only within each site to ensure a similar testing method and parallel results. (there are other good sites as well)
1. https://audioxpress.com/categories/vc-testbench
2. https://hificompass.com/en/speakers/measurements

Based only on the HD testing and price, I would buy the JBL A130, EQ/DSP it well and add the required subs (subs ought to be added to every speaker listed below in nearly all use cases IMHO)*
Now while I would like to see the results of a test, I would certainly never buy a speaker based only on an HD test, so now what?

Like so many products one needs to test drive, at this price and performance you must try a few speakers at home. ASR and a few other places can guide you close and then you make the final selections based on personal needs (some of those needs will be hard to know in advance).

*By the way the A130 does in fact sound/measure truly excellent EQ'd and room corrected at my home, it does sound very, very low in distortion when high passed to my subs.

JBL 708P

Genelec 8030c

JBL A130 (passive $300 USD retail currently $180 on sale)

ELAC UB5 (passive three way)

Neumann KH310A

Purifi Prototype (passive, ported/ not passive radiator)

 

[amirm]

The Purifi woofer is "state of the art and world class and EXPENSIVE" and yet you can see how the JBl woofer has better HD levels.

I have an updated version of the purifi speaker and it now has much less distortion.

 

[mitchco]

@mitchco have written before that there's an "industry standard" for mixing (mastering?) with calibrated 83 dB SPL that is often used, which is important information for accurate tonal balance during playback as well.

Contrary to popular belief, you bet there is. Here are a few:
EBU Tech 3276, “Listening conditions for the assessment of sound programme material: monophonic and two–channel stereophonic."
ITU-R BS.1116-3, “Methods for the subjective assessment of small impairments in audio systems”

Failing those, most audio pros refer to Bob Katz's:
How To Make Better Recordings in the 21st Century – An Integrated Approach to Metering, Monitoring, and Leveling Practices

Just outside of my profile pic is a calibrated SPL meter on the mixing desk. As our ears frequency response change with SPL, by quite a bit, it is important to realize that most mixes and masters follow the industry standards, a few mentioned above, and Bob Katz's K-metering system. So if you want to hear music the way it was intended, a good start is to listen at the same level that it was mixed/mastered so that the balance between bass, mids and treble sound like it should. i.e. at reference level our ears response is the most flat (relatively speaking).

For playback, I also engage a loudness control for below reference level. Here is a calibration procedure using JRiver: https://wiki.jriver.com/index.php/Volume#Loudness

FYI 120 dB SPL C weighted is the "threshold of pain" for your ears. At 110 dB SPL I have left concerts even with excellent ear protection as you can "feel the sound" being uncomfortable. PSA: protect your ears folks, invest in a SPL meter.

@amirm Perhaps speakers should be measured at "reference level" i.e. 83 dB SPL And then again at perceived as twice as loud which is another 10 dB SPL which will show any nonlinearities as the SPL goes up. I know it is supposed to be up to 105 dB SPL, and maybe that is an option, but sadly with the loudness wars still prevalent in pop, rock and pretty much anything that is mainstream music is (very) unlikely to have a DR greater than 10.

 

[Frank Dernie]

Like so many products one needs to test drive, at this price and performance you must try a few speakers at home.

I completely agree here, but that rules out a huge number of potential choices, depending on where one lives.
For example I may perhaps be able to arrange a demo of Revel but no chance for JBL. Keith @Purité Audio will always arrange a home demo of the splendid speakers he sells, and I can get KEF, Sonus Faber, Wilson, ATC, Dynavector, Focal and Magico for home demo.
Other than that it is blind hope.

 

[Absolute]

The problem with simple THD measurements of speakers is that we have no way of knowing what exactly is causing the distortion. It can be diffraction, port noise, cabinet resonances, rattling of wires or other parts loose in the box etc.
It just doesn't let us know what the actual issue could be. I thought my compression driver was broken when it suddenly measured horrible with tons of distortion, but it turned out to be a poor wire connection between the two membranes in the driver.
A little bit of testing with the wire revealed that any movement of that wire will lead to vastly different result, and very audible distortion;

All that stuff went away with fastening the wire properly. Lesson learned and an experience worth sharing before we put too much into THD testing without finding out what causes it.
If I didn't have the other speaker to cross check with, I'd just write this tweeter/speaker off as junk.

 

[Frank Dernie]

If I didn't have the other speaker to cross check with, I'd just write this tweeter/speaker off as junk.

I think this is a fundamental limit in testing one sample, particularly of inexpensive units.
It would be pretty normal for wide production tolerances.

 

[Absolute]

I think this is a fundamental limit in testing one sample, particularly of inexpensive units.
It would be pretty normal for wide production tolerances.

Agreed. While I'd never wish for Amir to spend needless time with double measurements or troubleshooting speakers for potential faults, it sure would be nice if the manufacturers would shed some light on how they solve practical issues like that.

But hey, I'm not the one wanting to sell speakers. I'm just the idiot getting really pissed when stupid stuff that could and should've been avoided mess up the sound.

 

[q3cpma]

Without question, Genelec makes truly superb speakers.
They also have a knack for ultra low harmonic distortion levels. I really feel that that spec is important, yet as long as it is not broken, it is more of a mental game than a reality. Turn your attention toward Port velocity, which is ONLY a problem once it is overloaded and once overload is suppressed any attempt to lower it further has no practical effect. I suspect HD is similar. While this varies with frequency and order, is really not the issue we make of it. Trouble is it is REALLY easy to measure it so nearly any reviewer using measurements is going to do just that, so now we see it all the time and get used to thinking (over thing?) about it more than it is worth. (Stereophile magazine, interestingly doesn't use HD testing in their reviews, which feature some nice comprehensive measurements)

Here are a few screenshots from here at ASR of HD testing.
One thing is look at how low that $300 pair, JBL A130 is - especially that 5" woofer, right? Crazy.
That Genelec 8030c is very overloaded in the bass and midbass at 96db and that is likely to get MUCH worse fast trying to go higher, at 86 it is truly spectacular.
I threw in the ELAC 3 way as an example of how a 3 way is not always a HD/(IMD?) solution.
The Purifi woofer is "state of the art and world class and EXPENSIVE" and yet you can see how the JBl woofer has better HD levels. I am not saying that the Purifi is bad, just that maybe HD testing is not really a prime indicator as this woofer so far has been highly reviewed elsewhere.

If you or any reader passing by this post, are not already a fan/reader. I like to read the driver tests at these two sites for general info. The sites testing can not be compared against each other, only within each site to ensure a similar testing method and parallel results. (there are other good sites as well)
1. https://audioxpress.com/categories/vc-testbench
2. https://hificompass.com/en/speakers/measurements

Based only on the HD testing and price, I would buy the JBL A130, EQ/DSP it well and add the required subs (subs ought to be added to every speaker listed below in nearly all use cases IMHO)*
Now while I would like to see the results of a test, I would certainly never buy a speaker based only on an HD test, so now what?

Like so many products one needs to test drive, at this price and performance you must try a few speakers at home. ASR and a few other places can guide you close and then you make the final selections based on personal needs (some of those needs will be hard to know in advance).

*By the way the A130 does in fact sound/measure truly excellent EQ'd and room corrected at my home, it does sound very, very low in distortion when high passed to my subs.

JBL 708P
View attachment 110585

Genelec 8030c
View attachment 110586

JBL A130 (passive $300 USD retail currently $180 on sale)
View attachment 110587

ELAC UB5 (passive three way)
View attachment 110588

Neumann KH310A
View attachment 110589

Purifi Prototype (passive, ported/ not passive radiator)
View attachment 110590

Everything you said it true, but let's say that I find reasonable to expect much better from 3500$/4000€ per pair speakers. Non linear distortion perception being a poorly researched domain, just aiming for the least amount is the only way.

 

[5th element]

2.5% is a lot but it is a narrow spectrum which may be the reason it wasn't audible to me.

It's second harmonic distortion. That's why it's inaudible. You need over 10% for that to be considered a problem. I've said this several times in the past already a bit of second harmonic here or there doesn't really mean a driver is struggling. Some produce quite a bit of 2nd order by design. Compression drivers are one of the types that tends to have much higher secpnd order than others. Often they have near nonexistent distortion of other orders but a decent splash of 2nd order.

 

[amirm]

@amirm Perhaps speakers should be measured at "reference level" i.e. 83 dB SPL And then again at perceived as twice as loud which is another 10 dB SPL which will show any nonlinearities as the SPL goes up.

My measurements are all at 86 dBSPL (with some rare exceptions). This provides a good balance between good SNR and not stressing the speaker.

For distortion measurements, I show 86 and 96 dB. With those two data points across many speakers, we get a good feel for how much distortion there is and how it scales with volume (linearity or otherwise). At this point I don't want to change these values and make new measurements incompatible with old.

 

[yourmando]

Also the 708P is not happy at 96dB as Amir correctly wrote in his reviews:

View attachment 110303
View attachment 110304

I personally would rather prefer distortion in the lower bass where its less audible (plus you can lower it by subs and/or near front wall placement and according room filters) and not creating IMD mess at the very important and audible mids at a 3-way design. Also on sound quality aspects I prefer the KH310, which can be partially seen also on the FR and HD plots, unfortunately Sound & Recording has only tested the 705P as it would be interesting to compare its IMD plot to the one of the KH310.

Fully agree. The KH 310 can crank to high SPL with low distortion, likely less IMD with the 3 way design, and no port resonances because it's sealed, which is pretty unique among its competitors.

The distortion below 40hz is handled well with crossing over to a good subwoofer array (I use 3 dual opposed 12" subs and DLBC for bass management). And you get 3-4 db more max output when crossing over 1 or more subs.

It's hard to get state of the art bass response anyway over a wide seating area w/o multiple subs, so the KH 310 is a good option if a sub is used.

Of course the comparable JBLs & Genelecs are amazing as well.