JBL HDI-1600 Speaker Review

[Sal1950]

Let's Get Ready To Rumble, HSU vs JBL
Breaking them in jamming to some Gordon Goodwin's Big Phat Band - Swingin For The Fences

 

[GXAlan]

Let's Get Ready To Rumble, HSU vs JBL
Breaking them in jamming to some Gordon Goodwin's Big Phat Band - Swingin For The Fences

View attachment 59616

Lots of old Adcoms, there. I know everyone says amp differences aren't audible, but I definitely heard differences between my GFA-555II's run as monoblocks and even a simple Parasound HCA-2205AT. The GFA-555II would be a fun amp to put under the lens of Amir's testing.

 

[thewas]

Also for a passive 3-way speaker with a relatively low bass-mid crossover frequency quite high inductivities and capacities for the corresponding low and high pass filters are needed, which when made with high quality air coils and foil capacitors are quite costly in comparison to the rest of the crossover parts or even the drivers.

 

[Sal1950]

The GFA-555II would be a fun amp to put under the lens of Amir's testing.

Until then,
https://www.kenrockwell.com/audio/adcom/gfa-555-ii.htm

 

[GXAlan]

how does the JBL provide better "dynamics"?

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

The emphasis does seem to be on efficiency here, but Amir getting that test speaker to around may also be a hint.

I have always considered good dynamics to mean that the compression is reduced at high levels so that for a given reference level, it can play loudly when the music or movies requires it to. So I suppose that is peak SPL and audibility at low volume as well.

 

[Senior NEET Engineer]

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

The emphasis does seem to be on efficiency here, but Amir getting that test speaker to around may also be a hint.

I have always considered good dynamics to mean that the compression is reduced at high levels so that for a given reference level, it can play loudly when the music or movies requires it to. So I suppose that is peak SPL and audibility at low volume as well.

I think differences in directivity and sound signature can also give that impression. Narrower directivity - higher ratio of direct vs reflected energy. Sound signature - adjusting EQ has been shown to increase "DR score" significantly.

 

[Ilkless]

I think differences in directivity and sound signature can also give that impression. Narrower directivity - higher ratio of direct vs reflected energy. Sound signature - adjusting EQ has been shown to increase "DR score" significantly.

And this also relates to the concept of "intelligibility" in HT and architectural acoustics.

 

[GXAlan]

Until then,
https://www.kenrockwell.com/audio/adcom/gfa-555-ii.htm

I have seen that review. Between my brother, cousin, and I we had used to own 7 of them more than 10 years ago. . So we were fans.

https://benchmarkmedia.com/blogs/application_notes/power-amplifiers-the-importance-of-the-first-watt

Benchmark has shown than ABX testing can show differences in amplifiers at low power and indeed, I find that I do a lot of listening at sub 1W levels.

Julian Hirsch was famous for suggesting that most amplifiers sound the same also wrote that SNR differences may play a role:

“Hirsch also found that small—minute, even—differences in amps’ comparative signal-to-noise ratios often had a tangible impact on their perceived sound.

The SNR difference was not audible as hiss per se. But he did find that a few extra dB of noise could subliminally mix with the program material and lend a very slightly “brighter” or “harder” character to the sound. Granted if amplifier “A” had a SNR ratio of 80 dB and amplifier “B” was 75 dB, both would be considered more than “quiet” enough for high fidelity purposes. But the difference between their SNRs could show up as a perceived difference in tonal character.”

From https://www.audioholics.com/audio-amplifier/the-sound-of-an-amplifier

——
Now that you have those HDI’s, enjoy. If you get a chance, you should try a Parasound HCA-2205a. I ended up swapping 5 Adcoms for a single one of those. Originally got the Parasound for a second system, but discovered that it sounded better. This was almost ten years ago, a level matching was to the nearest dB. For all I know, the Parasound may simply have been 0.4999 dB louder. It may also be that first watt difference.

 

[tuga]

Of course not. All measurements are good to take--one can never have too much data. However, one needs to understand what the measurements are telling you such that you can put them in the context of all the compromises you're making when you design the speaker.

My wild guess in this case is that distortion could be blamed on the driver selection. It could be that midbass drivers that reduced it performed more poorly in bass extension or power handling--and they viewed those to be much more audible problems than the distortion you highlight--especially in the case of the HDI which is largely 2nd harmonic and may not be audible at all.

It looks like you've focused on distortion at the low-end of the spectrum (likely inaudible at low to mid listening levels) and that has nothing to do with the crossover.
I am referring to the high level of distortion at 2kHz.

If the increased distortion is the result of the hard cone breakup modes (and there is a notable ridge in the CSD plot) then can we not infer that the cause is a poorly designed crossover or at least an unfit-for-purpose low-pass frequency (which is poor design)?

The frequency response is flat on-axis and to the sides of the speaker.
If we were to believe that frequency response measurements (spinoramas) alone were enough to judge a speaker this one would be almost perfect (if we ignore the vertical dispersion characteristics).

 

[Absolute]

It looks like you've focused on distortion at the low-end of the spectrum (likely inaudible at low to mid listening levels) and that has nothing to do with the crossover.
I am referring to the high level of distortion at 2kHz.

If the increased distortion is the result of the hard cone breakup modes (and there is a notable ridge in the CSD plot) then can we not infer that the cause is a poorly designed crossover or at least an unfit-for-purpose low-pass frequency (which is poor design)?

The frequency response is flat on-axis and to the sides of the speaker.
If we were to believe that frequency response measurements (spinoramas) alone were enough to judge a speaker this one would be almost perfect (if we ignore the vertical dispersion characteristics).

Jumping to conclusions helps no one. This could be port leakage typical of two-way speakers, distortion from the compression driver or a weird artifact from the klippel measurement due to some reflections (ridges in the frequency response around 2 k in many measurements) or other stuff I know nothing about, but saying it's a poor crossover design when the frequency response on and off-axis is good and the speaker sounds superb just doesn't compute with me.

 

[tuga]

Jumping to conclusions helps no one. This could be port leakage typical of two-way speakers, distortion from the compression driver or a weird artifact from the klippel measurement due to some reflections (ridges in the frequency response around 2 k in many measurements) or other stuff I know nothing about, but saying it's a poor crossover design when the frequency response on and off-axis is good and the speaker sounds superb just doesn't compute with me.

The "speaker sounds superb" is subjective and not an acceptable measure of performance.

Cone breakup is a possibility (which is why I wrote "if"), port leakage is another (though perhaps a bit too high in frequency and amplitude) and even the measurement artifact theory. Maybe it's something worth investigating.

 

[Absolute]

Definitely worth investigating!

 

[dinglehoser]

The "speaker sounds superb" is subjective and not an acceptable measure of performance.

Cone breakup is a possibility (which is why I wrote "if"), port leakage is another (though perhaps a bit too high in frequency and amplitude) and even the measurement artifact theory. Maybe it's something worth investigating.

I find it curious that the distortion spike around 2k is *exclusively* 2nd order. If it was caused by cone breakup, that would theoretically mean a) we'd see a spike at 4k and b) we'd also see a 3rd order spike at around 1.33k ... right? I don't see evidence of either.

 

[tuga]

I find it curious that the distortion spike around 2k is *exclusively* 2nd order. If it was caused by cone breakup, that would theoretically mean a) we'd see a spike at 4k and b) we'd also see a 3rd order spike at around 1.33k ... right? I don't see evidence of either.

You may be right. A CSD plot of the isolated mid-woofer would help verify that. A close-mic'ed measurement of the port would be interesting as well.

 

[dinglehoser]

You may be right. A CSD plot of the isolated mid-woofer would help verify that. A close-mic'ed measurement of the port would be interesting as well.

@amirm no longer has the 1600s in his possession, alas. We'll have to wait until he gets his hands on another model in the line.

 

[BYRTT]

...A CSD plot of the isolated mid-woofer would help verify that...

My bet for that distortion hump is L(e) value differences between the two drivers, if woofer was measured isolated there would be no distortion there and same goes for compression driver, distortion problem is only in the area where they start to cooperate and think nothing to do about it in passive way other than use woofer with advanced motor that often offer relative lower L(e) value or make crossover slope as steep as possible to get over their cooperation region as soon as possible its their cycles that start drift some microbit because L(e) curve is not exactly 100% the same.

 

[Dj7675]

Would the HDI-1600 be able to play at higher SPL without distorting than the Revel M16?

 

[tuga]

My bet for that distortion hump is L(e) value differences between the two drivers, if woofer was measured isolated there would be no distortion there and same goes for compression driver, distortion problem is only in the area where they start to cooperate and think nothing to do about it in passive way other than use woofer with advanced motor that often offer relative lower L(e) value or make crossover slope as steep as possible to get over their cooperation region as soon as possible its their cycles that start drift some microbit because L(e) curve is not exactly 100% the same.

Can you hypothesise on why only some of the speakers tested seem to produce such a significant distortion in the crossover region?
(the JBL HDI-1600, the Revel M16, the Elac AS-61, the Infinity R162 and the Infinity RC263)

 

[BYRTT]

Can you hypothesise on why only some of the speakers tested seem to produce such a significant distortion in the crossover region?
(the JBL HDI-1600, the Revel M16, the Elac AS-61, the Infinity R162 and the Infinity RC263)

Could be those woofers used there have bit huge or over avarage L(e) value compared to other builds without that raising distortion into XO region, or L(e) value of used tweeter is exstreme low.

 

[amirm]

Would the HDI-1600 be able to play at higher SPL without distorting than the Revel M16?

Yes.