I am a bit dissapointed that one speakers distortion in 5Khz region is a lot higher than then other. Normal?

[Pdxwayne]

I did some REW measurements today to better
sync my speakers to my subs. While making measurements, I noticed one speaker have odd shape distortion around 5.45 Khz region, but not the other. I wonder if this this typical of speakers variations?

I measured at ~10 ft away and 3ft away from speakers, same issue. Switch speaker from left to right and issue followed that speaker.

Below are the measurements, in room, mike 3 ft away from speaker, between tweeter and woofer.

Speaker with odd distortion shape:

The other one looks more normal:

 

[DonH56]

Seems suspicious to me though I am no speaker expert. The "bad" speaker also exhibits a rising response around 2 kHz while the "good" is falling in distortion. I would suspect a crossover or driver issue. One thing you might try, if not too difficult, is to swap the speakers' positions and see if the response follows the speaker or stays on the same side. If the former, suspect the speaker; if the latter, suspect the amp chain. Room reflections could contribute but since the frequency response is the same that seems unlikely (to me).

HTH - Don

 

[Pdxwayne]

Seems suspicious to me though I am no speaker expert. The "bad" speaker also exhibits a rising response around 2 kHz while the "good" is falling in distortion. I would suspect a crossover or driver issue. One thing you might try, if not too difficult, is to swap the speakers' positions and see if the response follows the speaker or stays on the same side. If the former, suspect the speaker; if the latter, suspect the amp chain. Room reflections could contribute but since the frequency response is the same that seems unlikely (to me).

HTH - Don

Yes, already did the swap and ruled out amp and room issue.

It is indeed speaker specific.

: (

Thanks for checking!

 

[blueone]

Perhaps a silly question... have you checked the tightness of the tweeter mounting screws?

 

[Pdxwayne]

Perhaps a silly question... have you checked the tightness of the tweeter mounting screws?

Good idea.

Unfortunately, not sure how to do that with this speaker....

 

[blueone]

Is the perforated part essentially a metal grille meant to be pried off? Perhaps some forum somewhere has the answer. Or the grille itself could be the problem... another long shot.

 

[Pdxwayne]

Is the perforated part essentially a metal grille meant to be pried off? Perhaps some forum somewhere has the answer. Or the grille itself could be the problem... another long shot.

I will ask manufacturer directly. Thanks!

 

[McFly]

For better looking at driver faults, measure with the mic 20mm from the driver or grille. Turn the volume DOWN compared to what you would when measuring at listening position or the mic will likely overload (getting 110db or more).

 

[Pdxwayne]

For better looking at driver faults, measure with the mic 20mm from the driver or grille. Turn the volume DOWN compared to what you would when measuring at listening position or the mic will likely overload (getting 110db or more).

Just want to confirm. 20mm, 2cm, less than 1 inch, correct? Thanks!

 

[restorer-john]

I'd perhaps slowly sweep and identify the actual issue. My bet it is a physical problem with the driver/voice coil/grille/internal component etc.

 

[Pdxwayne]

I'd perhaps slowly sweep and identify the actual issue. My bet it is a physical problem with the driver/voice coil/grille/internal component etc.

Just my luck with buying speakers....

My other pair (different model) also have a serious issue with tweeter freq response on one speaker.


At least this time the freq response still looks OK.

Thanks for the suggestion!

 

[McFly]

Just want to confirm. 20mm, 2cm, less than 1 inch, correct? Thanks!

Yes, also 3/4 inch. Low to medium volumes. Using REW? Johns idea also good, could do a generator slow sweep and hear the issue isolated, after finding the offending frequency with a sweep. Just use low volumes, constant sine waves on tweeters is pretty mean.

 

[McFly]

Just my luck with buying speakers....

My other pair (different model) also have a serious issue with tweeter freq response on one speaker.


At least this time the freq response still looks OK.

Thanks for the suggestion!

Hmm this a bit suspect, can you describe your measurement set up in more detail? Applications, options for measurements and hardware?

 

[Pdxwayne]

Hmm this a bit suspect, can you describe your measurement set up in more detail? Applications, options for measurements and hardware?

That other pair's issue was found a couple years ago.

: )


Mic: Dayton audio Emm6

DAC: Gustard X16

ADC:Focusrite Scarlett Solo

Laptop with REW.

Thankfully those 2nd order distortion still not too bad, especially the peak would be over 10khz...

 

[HiFidFan]

I have nothing to offer on the distortion issue, but that tweeter cover looks like it has a Torx cutout in the very center. It might unscrew, instead of 'pop' off, with the proper tool.

 

[Pdxwayne]

I have nothing to offer on the distortion issue, but that tweeter cover looks like it has a Torx cutout in the very center. It might unscrew, instead of 'pop' off, with the proper tool.

Thanks for the suggestion. Unfortunately I don't have plastic tool.

I would not use a metal tool near the top of tweeter.... Learned that the hard way....

 

[Pdxwayne]

Hmm, doing 1" measurement I got strange distortion results.....

As compared to 3 ft measurement:

And 9.5ft:

 

[Juhazi]

Room issue, or mic mounting? Please play that 5,5kHz sine tone with REW's generator and try to locate the source of distortion by listening very close to the spaker. should be easy! Measurements further than 3´or 1m always pick up extrinsic sounds to some extent.

Toggle tags on the bottom of distortion window to show 2nd to 5th distortion separately. 2nd and 3rd are usually dominant and by my experience high odd order is typical for mechanical resonances. Resonances also are not lineat to spl, they need some energy to wake up and might suppress in % when amplitude gets too high. Nearfied at 1" will show only driver's problems, not those from the box, wire connections etc. and it is difficult to use high enough spl without overdriving the mic.

So, distortion is very difficult to measure and analyze, and an amateur must take several different measurements!

 

[McFly]

Cant see nearfield driver distortion. Grille causing distortion maybe. Is it not seated properly compared to other speaker?

 

[Pdxwayne]

Room issue, or mic mounting? Please play that 5,5kHz sine tone with REW's generator and try to locate the source of distortion by listening very close to the spaker. should be easy! Measurements further than 3´or 1m always pick up extrinsic sounds to some extent.

Toggle tags on the bottom of distortion window to show 2nd to 5th distortion separately. 2nd and 3rd are usually dominant and by my experience high odd order is typical for mechanical resonances. Resonances also are not lineat to spl, they need some energy to wake up and might suppress in % when amplitude gets too high. Nearfied at 1" will show only driver's problems, not those from the box, wire connections etc. and it is difficult to use high enough spl without overdriving the mic.

So, distortion is very difficult to measure and analyze, and an amateur must take several different measurements!

View attachment 119650

Thanks for the suggestion. Close by means closer than 3 ft, maybe 1 ft OK?

The problem with my current setup is that my speakers would make contant low level noise (a bit like ground loop noise) that is noticeable up to 12", especially when nothing is playing. I believe it is amp specific issue. So listening too close I get distracted by that low level noise.