JBL A130 distortion compared in-room with several similar monitors.

[ROOSKIE]

Here are some in room Harmonic distortion, measurements of several speakers.
After seeing the low distortion in the JBL A130 review (with particular regard for the little 5.25" woofer), I was intrigued/impressed and I bought a pair. I wanted to compare with other speakers and confirm this low distortion.
I have more speakers to compare with in the future, including more expensive models, but for now what follows is from this afternoon.
I was working with limited time so the tests are not as comprehensive as I intended... next time I will try to go deeper.

• It is very cold here and Winter, zero testing can be done outdoors for several months, thus all testing was done IN MY LISTENING ROOM. This data can not ever be compared with any other testing situation directly, especially anechoic.
• It is still very useful IMHO due to using the same method on each set, therefore I can get a general sense of each speaker.
• Each speaker was tested multiple times to ensure consistency.
• I separately tested both speakers in a stereo pair to ensure consistency.
• This is a mono test.
• Levels are set via pink noise using C-weighted meter. Minor variation will exist here.
• The speaker was on a stand 1/2 the distance from floor to ceiling and well away from the walls.
• All walls were well out of the way, the ceiling however is only 8 feet here. (can't stand that and need to move soon)
• UMIK mic, calibrated, 13" from the tweeter. (13" is about 1/3 meter)
• Measurement length 1M (takes about 22seconds to run each sweep)
• SPL 96db and a few at 106db, this is somewhat equal to 86db @ 1meter and 96db @ 1meter. *note that while calculations for SPL/distance are accurate, since speakers are often designed for listening farther away than 13" these tests may NOT represent actual distortion levels at the listening position with special regard for the crossover region.*
• The bass region ought to be measured separately when doing this stuff inside - with the mic as close as possible. I did not have time. What is here is still useful for a comparison, just know that is may differ quite a bit from an anechoic test.
• The amplifier used for this test was of lowish quality. It was what I had free. Monoprice 605030.
• Note the noise floor, while generally this is a quiet room it is still a factor here.

SPEAKERS TESTED TODAY with pricing per PAIR(2 units)

• JBL A130, $300 retail ($150 refurb)
• JBL Studio 530, $600 retail ($300 sale)
• Wharfedale 11.2, $600 retail ($200 clearance)
• Infinity RC263, $1000 retail ($320 sale)
• A. DIY 2way Active, Dayton drivers, EST DIY for $250/300 **(6.5", RS180 & 1.125"RS28A)
• B. DIY 2way Active, Dayton-Peerless drivers, EST DIY for $200/250 **(8", PA200 & 1", DX25TG59-04)

The Infinity RC263 is a sealed box, all others are ported.

JBL A130 @ 96db 1/3 meter & 106db 1/3 Meter

JBL 530 @ 96db 1/3 meter

Wharfedale 11.2 96db 1/3meter

Infinity RC263 96 7106db @ 1/3 meter

DIY A. Active (Dayton 6.5", RS180 & Dayton 1.125"RS28A)*(uses 33hrz highpass)*

DIY B. Active (Dayton 8", PA200 & Peerless 1", DX25TG59-04) *(uses 37hrz highpass)*
Both normalized 96&106db @ 1/3 meter

Short summary.
All in all, this is great performance for a $300 retail priced speaker (A130.)
Very low distortion down to 60hrz, use a highpass below this as the woofer unloads fast at volume.

Subjectively I have played approx 3 hours on the A130 with NO room correction or EQ to get a feel for it. Very nice. Some audible flaws that I bet EQ and room correction will cure.
Looking forward to spending some more time with it. Frankly this seems to be a really nice speaker.
I know some folks want to see the effects of EQ and High pass filters on harmonic distortion. I will post fairly soon after I take some more measurements along those lines.

 

[witchdoctor]

This is a very nice comparison, thanks for posting.

 

[thewas]

Thank you, very interesting, also the low bass distortion of the Infinity and your DIY ones at 96 dB at 1/3 meter.

 

[Blumlein 88]

Thank you for posting this data.

A couple tips on displaying it. I think using at least 1/12th smoothing or even 1/6th (our ear is close to this much of the range) makes it easier to see what the trend is.

And it appears (like is usually the case with cone speakers) 2nd and 3rd harmonic are really all that are at levels that matter. So showing 2nd, 3rd and THD make for a cleaner graph.

Please don't take offense. I am glad you collected this data for us to see.

 

[thewas]

A couple tips on displaying it. I think using at least 1/12th smoothing or even 1/6th (our ear is close to this much of the range) makes it easier to see what the trend is.

In REW the fundamental and harmonic plots derived from sweep measurements are smoothed to 1/24 octave. This cannot be adjusted.
https://www.roomeqwizard.com/help/help_en-GB/html/graph_distortion.html

And it appears (like is usually the case with cone speakers) 2nd and 3rd harmonic are really all that are at levels that matter. So showing 2nd, 3rd and THD make for a cleaner graph.

I agree there and usually show only 2nd, 3rd and 5th.

 

[ROOSKIE]

Thank you for posting this data.

A couple tips on displaying it. I think using at least 1/12th smoothing or even 1/6th (our ear is close to this much of the range) makes it easier to see what the trend is.

And it appears (like is usually the case with cone speakers) 2nd and 3rd harmonic are really all that are at levels that matter. So showing 2nd, 3rd and THD make for a cleaner graph.

Please don't take offense. I am glad you collected this data for us to see.

Hi thanks for the feedback.
No offense at all.
I don't want to smooth the distortion graphs.
I would smooth frequency response but never distortion.
I did anticipate some folks might not want the 4th and 5th, I had to mull it over but in the end because I like seeing it I left it in.
I will consider leaving off next time.
It is nice for seeing possible resonances such in wharfedale 11.2 (port resonance maybe) & for seeing how much crap is produced when drivers exceed xmax such as below port tunning or driven to high excursion in a sealed box.

 

[375HP2482]

Is there a particular reason why the 106 dB measurements for the JBL 530 are not present? Did I miss something with my off-brand browser?

That level may seem excessive to some, but it equates roughly to 86 dB at 10 feet. Which is not unreasonably loud on occasion.