Evaluating JBL LS-80's place at Audio Video Logic. Opinions please....

[jpw]

JBL just shipped me a pair of LS-80's for evaluation purposes. Equipment used was a PS Audio Perfect Wave Transport, McIntosh C-48 preamp with built in DAC, Krell EVO 403 400 wpc amplifier and Nordost cables. First impressions with no break in of any kind was that they sounded rather thick and boxy, obviously emphasizing the 125-250hz region. The presence region that the compression driver covers seemed recessed almost like JBL was trying to hide the fact that they use horn loaded drivers. I cut the 125hz region with the graphic EQ control on the C-48 about 6db which restored a much better tonal balance. After applying the EQ, the reticent midrange presence seemed less of a problem. Also a little bit of sibilance from the tweeter was audible. I'm letting them play over night and will report back on them after break in which hopefully will solve the problems.

How much of an improvement can I expect after break in? Or are these characteristics largely just part of their sound?

[MikeBrewster77]

There have been mixed reviews by the few on the forum who have heard them. Your specific mention of the recessed mid's, however, prompted me to do a search as I distinctly remembered having previously read a very similar sentiment here on the forum. And sure enough, I had: http://www.audioheritage.org/vbulletin/showthread.php?22877-JBL-LS80-what-can-you-say-about-them&p=270051&viewfull=1#post270051

Then again, not all that I've read has been negative, e.g.: http://www.audioheritage.org/vbulletin/showthread.php?29845-Jbl-ls-series-(toronto-canada)&p=299755&viewfull=1#post299755 (http://www.audioheritage.org/vbulletin/showthread.php?29845-Jbl-ls-series-%28toronto-canada%29&p=299755&viewfull=1#post299755)

All of that said, I've never heard them myself. I would (as I'm sure others would as well) be interested to hear your thoughts once they've been given a decent run.

[jpw]

My 2nd listening test was conducted after about 15-20 hours of break in. Same ancillary equipment as listed before. Although break in did reduce upper bass congestion some and improve overall openness, my opinion hasn't changed that much.

So I broke out my 1/3 octave RTA and measured them this time in a couple of different positions to try to fix the problem through relocation. BTW, the room is irregularly shaped and large at 24 foot by 22 foot with a 9.5 foot suspended ceiling. As I suspected, they do not measure with a recessed midrange, at least not the midrange frequencies the midrange compression driver covers which is about 1.5khz to 5khz. What makes them sound recessed in the midrange is a preponderance of upper bass and lower midrange (about plus 6-7db) in the 100-250hz region. This region simply overpowers the octaves on either side of it. The room is known to contribute only 2-3db error in this range.

Moving up the frequency range, a 4-5db dip around 500-600hz, then a climb back up at 800hz to plus 3-4db levels, then down again and then reasonably flat from 1.5khz to 5khz. Into treble territory, another 4-5db dip in the 6khz-8khz showed up. Then above here the tweeter starts climbing straight up starting at 10khz and is up 6db or so at 20khz.

The 40-60hz region was down about 6db from flat. This amounts to a huge and obvious 12db swing or more difference in octave to octave tonal balance. Of this error about 4db of the lack of 40-60hz is known to be the room.

Anybody that has learned to interpret frequency response curves with subjective listening knows that peaks that are followed by dips on either side always make the peak sound worse than it measures. This behavior repeats itself several times with the LS-80. The result is a muffled boxy sound with a distinct lack of presence coupled with a tinkly even sibilant top end on some recordings.

I have loved JBL's for years so don't think I'm a JBL basher. I've owned L-100's, 4430's and still have triamped JBL PRO speakers (custom) and now Everests. I will try the LS-80's in another room with some more break in time on them, but suspect that these were tuned for a midfi customer rather than a high end ear. I also found the cabinets lightly built with thin side walls that sounded clearly hollow when rapped on with my knuckles. I also suspect that there are some cabinet resonance/stored energy issues in the lower midrange and upper bass adding to the coloration I hear.

[MikeBrewster77]

I have loved JBL's for years so don't think I'm a JBL basher.

I certainly wouldn't have taken your review that way, nor would I expect that anyone else would either. It sounds like you've given them a balanced assessment thus far, and are continuing to explore how they may sound under different conditions. Nothing wrong with that, and it hardly makes you a basher.

Not every member of the team can be an A-player ... and JBL has had a few B players in its time. The LS80 might just be one of those, or it might just be "what it is" for the price point. Like I said, I haven't heard it, so I can't give a credible opinion; but you offering yours doesn't make you any less of a JBL fan.

So as the kids these days say "it's all good." Thanks for sharing your thoughts and let us know how it works out.

[JBLAddict]

all very interesting, and all spot on to the way I heard em as well

[jpw]

It's good to know I can do some honest reporting on the forum. Also good that I'm not the only one that noticed the same sonic traits. I really had high hopes for this speaker and thought the driver compliment and basic design layout a good one. Execution though is everything. Regarding the voicing of the LS-80, I suspect that JBL needs less of a committee approach. I prefer speakers that follow a gifted designers convictions.

[Regis]

So I broke out my 1/3 octave RTA and measured them this time in a couple of different positions to try to fix the problem through relocation. BTW, the room is irregularly shaped and large at 24 foot by 22 foot with a 9.5 foot suspended ceiling. As I suspected, they do not measure with a recessed midrange, at least not the midrange frequencies the midrange compression driver covers which is about 1.5khz to 5khz. What makes them sound recessed in the midrange is a preponderance of upper bass and lower midrange (about plus 6-7db) in the 100-250hz region. This region simply overpowers the octaves on either side of it. The room is known to contribute only 2-3db error in this range.


Anybody that has learned to interpret frequency response curves with subjective listening knows that peaks that are followed by dips on either side always make the peak sound worse than it measures. This behavior repeats itself several times with the LS-80. The result is a muffled boxy sound with a distinct lack of presence coupled with a tinkly even sibilant top end on some recordings.

I

Glad I saw this and I agree. I think that is what is wrong with some of the other frequently discussed JBL lines here. Not so much a 'recessed midrange', but an overpowered peak on either side. Naturally, placement counts and it may be that placement may alleviate this.

[jpw]

Regarding different placement solving the tonal balance problem, I was unable to accomplish this. I tried two different rooms of varying sizes and a number of positions
relative to the back and side walls. None of them came even close to fixing the problems even with the help of my RTA. Sorry to say, I will be sending these back to JBL rather than representing them on my sales floor. In my opinion, a thorough retuning of the system and a more rigid less resonant cabinet is what they need.