Speakers distortion

[chahahc]

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Do woofers usually have all those high order distortion products? Or might that be some low level nonlinear funkiness of the class D amps or something?
I got a pair 306p speakers on that sale last month for $150 and, running them through a umc202hd, I'm also hearing a "fizzy" quality to the sound.

 

[Blumlein 88]

Do woofers usually have all those high order distortion products? Or might that be some low level nonlinear funkiness of the class D amps or something?
I got a pair 306p speakers on that sale last month for $150 and, running them through a umc202hd, I'm also hearing a "fizzy" quality to the sound.

I'm not Ray, but having those higher order components isn't unusual for woofers. Depending on cabinet tuning and room nulls combined with our sensitivity to sound dropping as frequency decreases, sometimes the harmonics are mostly what you are hearing.

 

[RayDunzl]

Do woofers usually have all those high order distortion products?

Don't know. I don't get out much, so don't know about other drivers.

I figure the little plastic cones in the JBL 3 series are not at the apex of engineered materials, nor is the chip-amp the last word in amplification.

They're relatively cheap, work fine at moderate sound pressure levels.

 

[DonH56]

Do woofers usually have all those high order distortion products? Or might that be some low level nonlinear funkiness of the class D amps or something?
I got a pair 306p speakers on that sale last month for $150 and, running them through a umc202hd, I'm also hearing a "fizzy" quality to the sound.

IME, yes. Woofers and subs receive the bulk of the power and we are less sensitive to their distortion since some of the frequency band is below the range we normally hear. Look at the equal-loudness curves; even at 80 dB (loud to me) in the midrange (1 kHz), a 50-Hz tone needs to be around 100 dB to sound as loud, and that means 100 times the power all else equal. Larger cone area, stronger/bigger magnets, greater linear displacement and all that jazz helps a lot but it is still a lot to overcome. I do not think it has anything to do with the amps unless they are flat-out clipping; the demands on the driver are much greater. It needs to generate much higher pressure levels from a much large area without the cone flexing, spider or surround limiting movement, and voice coil and magnet assembly remaining linear without appreciable hysteresis. It's tough.

IMO - Don

 

[Floyd Toole]

Do woofers usually have all those high order distortion products? Or might that be some low level nonlinear funkiness of the class D amps or something?
I got a pair 306p speakers on that sale last month for $150 and, running them through a umc202hd, I'm also hearing a "fizzy" quality to the sound.

Just a thought: it is possible that the "fizzy" sound you hear is "rub and buzz", caused by mechanical contact between the voice coil and the pole piece. Press gently on the center of the dust cap and listen as the cone moves in and out. Or, drive the woofer with a very low frequency pure tone causing large displacements and listen. You can also push on the surround at different points to see if it is an asymmetrical problem. If any of the above happen, you likely need a new transducer.

 

[chahahc]

Just a thought: it is possible that the "fizzy" sound you hear is "rub and buzz", caused by mechanical contact between the voice coil and the pole piece. Press gently on the center of the dust cap and listen as the cone moves in and out. Or, drive the woofer with a very low frequency pure tone causing large displacements and listen. You can also push on the surround at different points to see if it is an asymmetrical problem. If any of the above happen, you likely need a new transducer.

Interesting. But it’s not a rub and buzz sound. I tried poking and prodding the woofer cones and didn't hear anything so I don't think it's a mechanical misalignment. I should have mentioned that I can also hear it in the tweeters. It's a like a fizzy (sizzly?) sound quality up in the high frequencies that ends up giving me listening fatigue after 20-30 minutes. I don't know what it is. Maybe it's from the umc202hd? But amir and a few others measured that dac series and they seemed to perform well. Well, I might just be expecting too much from a $150 pair of powered speakers.

 

[Krunok]

The only measurements I've seen that smoked the ML on distortion was @dallasjustice M2 setup.

Red JBL M2, Green MartinLogan (at elevated SPL to get closer to the measurement level he took)

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https://www.audiosciencereview.com/...ital-crossovers-w-subs.2369/page-3#post-66732

@RayDunzl , you may find this interesting - few days ago I ran into this review of ML ESL11A and the distortion graph was quite different than yours (from what I can see the level was app 85dB, hard to tell precisely as the scale is off but it doesn't seem lower than that):