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JBL L52 Classic review by Erin's Audio Corner

korps said:
I moved the speakers a lot further apart and that improved the sound immensely. There's way more air in the sound now that was missing before. Had to move one of them off my desk onto a separate stand though (read: stack of boxes).

But they're still a bit too punchy.
Is there an amp that could tame the punchy temperament of the L52 and make them a bit leaner?
Click to expand...
Equaliser APO and peace gui on your PC will be 100x more effective than a different amp
 
korps said:
I moved the speakers a lot further apart and that improved the sound immensely. There's way more air in the sound now that was missing before. Had to move one of them off my desk onto a separate stand though (read: stack of boxes).

But they're still a bit too punchy.
Is there an amp that could tame the punchy temperament of the L52 and make them a bit leaner?
Click to expand...
It's a studied phenomena. Many speakers experience a bass boost around 160-200Hz from the desktop surface. Here is a study involving 69 speakers and a desktop. The authors derive an generalized notch EQ to deal with the boost caused by the desk.

1753770158581.png



The notch is based on the median of the responses they measured. Your mileage will vary based on your desk and room. If you can't measure, you can start with a 160Hz notch, -3 or -4 dB, Q=3, and see what helps the most.

As already mentioned, no amp will do this. EQ will. :cool:
 
MAB said:
It's a studied phenomena. Many speakers experience a bass boost around 160-200Hz from the desktop surface. Here is a study involving 69 speakers and a desktop. The authors derive an generalized notch EQ to deal with the boost caused by the desk.




The notch is based on the median of the responses they measured. Your mileage will vary based on your desk and room. If you can't measure, you can start with a 160Hz notch, -3 or -4 dB, Q=3, and see what helps the most.

As already mentioned, no amp will do this. EQ will. :cool:
Click to expand...

My boost is at around 80hz, and another small one at 130hz. Actually got a dip around 160hz-200hz. Already EQed them out. It helped a lot with the buildup, but the bass still sounds off, so there's not much more I can do with EQ I feel. It's more the temperament of the speaker that's the problem at this point, rather than one specific frequency.

So my options are different speakers, or a different amp. Or if the issue really is desktop reflections, I suppose moving both speakers off the desk onto separate proper stands is an option too. My experiences with these speakers mirrors pretty much everyone else's I've seen, including Erin's, so I'm more inclined to believe it's the speakers rather than the desk. But I'm willing to give them a fair chance.
 
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Went against everyone's advice and got a new amp (TEAC AI-303). Wow, the sound is so much deeper and much more controlled than before. Not flat and bloated as with my previous amp. Everything that was missing before is there.
 
korps said:
but the bass still sounds off, so there's not much more I can do with EQ I feel. It's more the temperament of the speaker that's the problem at this point, rather than one specific frequency.
Click to expand...

That's gonna be a room thing really, amp fixing this is definitely gonna be placebo. Don't know of any amp that is going to fix response swings upwards to 10db or more, which is what most rooms impart. Fairly certain if you swapped amps and measured the responses would just overlap.
 
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Ktacos said:
That's gonna be a room thing really, amp fixing this is definitely gonna be placebo.
Click to expand...
Right, I forgot to mention, that was a mostly a resonance issue, fixed it by putting thicker cork pads underneath the speakers to dampen vibrations. But that was months before I got the amp, and not what I was referring to in my latest post. The TEAC improved the sound quite a bit in addition to that. And it runs a lot cooler and more reliably as well, and I consider that a worthy upgrade in and of itself.

So all in all, vibration damping and a new amp helped a lot, EQ helped barely.
 
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korps said:
So all in all, vibration damping and a new amp helped a lot, EQ helped barely.
Click to expand...

I'd wager you didn't apply EQ very well if this was the case. EQ is several times more powerful of a signal alteration tool than any dampening pad or amplifier. I welcome being corrected but I'm skeptical any of the changed you've made are having the effect you claim. Desks are pretty nasty things for a speaker, they require very focused and often complex EQ filter to help alleviate their effects. If you weren't applying that sort of EQ, typically software generate via REQ, then you aren't really experiencing the benefits of EQ.

Desks bad, cause lots of problems. I took mine out and made a custom desk that is basically a treatment panel with a nice wooden frame and place for a mouse and keyboard. Not practical for most people but it is what it is. Gonna need a lot more than ~150hz cut to fix this mess, which is what most desks look like. Just a giant comb filter applied to the whole response. Red is no desk. Green is with desk.

desks bad.jpg


It would be cool to see your before and after data. I am however skeptical of your claim of a dip at the common desk frequency reflection point of ~150hz because it doesn't make sense to have a dip there. A dip would typically be caused by a wave that has a phase that is closer to the inverse of the initial speaker wave, meaning it would likely be delayed quite a bit and come from reflection point not in the front of the speaker, common example being front wall reflection dips. One should typically see constructive interference at ~150hz giving you a peak. Anything is possible though.
 
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You're making too many assumptions, my man. I've already solved my problem with cork so I'm not interested going on a wild EQ goose chase.
 
None of your advice has been helpful. I'm happy knowing I found a solution without any misdirected advice from here. That's all I need.
 
MAB said:
None of your statements are factual.
Click to expand...
Neither are yours. You're working on assumptions and seem to think EQ is the only solution to every audio-related problem. Sorry, but I'm joining your cult.
MAB said:
Your Teac amp fixing FR issues
Click to expand...
Never claimed it did, it was the damping that fixed the resonance issues I was having. Could be many reasons the amp sounds better, better power efficiency, maybe the old amp was simply a dud etc. EQ isn't going to fix that.
 
Next time you give advice to people come with multiple plausible suggestions instead of religiously suggesting only one without having all the facts. All I have to say, thanks.
 
And the cultists have arrived to crucify the non-believer.
 
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I think you will find it is you who is the believer.
Keith
 
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