Misc. driver distortion measurements

[eb15]

Here are some (poorly done) REW/jbox distortion measurements that
I did this morning to help me decide on some driver and crossover ideas.
I'm still a newbie at this...

hardware: jbox where supplied electret microphone was approx 1 meter away.
snell k cabinet used though some drivers didn't quite fit...

First up 8" woofers

dayton dsa215-8 8" designer series aluminum cone



dayton da215-8 8" aluminum cone



dayton rss210hf-4 aluminum cone




10" dayton dsa270-8 designer series aluminum cone sticking out an inch or two from 8" woofer hole.




5" dayton dsa135-8 designer series aluminum cone, not quite fitting into a smaller type M cabinet on top of type k box


next up assorted tweeters for a 2-way

seas 19tff1 3/4"



peerless d19td05 3/4" (purchased recently through parts-express.com)


sb acoustics sb19st-c000-4 3/4"


sb acoustics sb26st-c000-5 1"


peerless bc25tg15-04 1"


dayton dc28f fabric dome


dayton old rs28a aluminum dome

[eb15]

Mods you can move this.
I didn't realize there was a driver testing sub category

[eb15]

Started project to rebuild a snell type m cabinet with current drivers, and crossover parts.
An initial Type M redesign. Snell Type M cabinet is 7.5-in wide 11-in tall 5.5-in deep.
driver rebates need rework to fit new new drivers.
dayton designer series 5" aluminum cone woofer
sb acoustics SB19ST tweeter

2-way crossover in the style of Peter Snell's original type k, e, etc. speakers.
12dB/octave electrical around 2500Hz. Low parts count. (no zobels, etc.)
Woofer crossover has some baffle step compensation. (the slope between 200Hz and 1000Hz)
Recommended parts: solen 16ga air core inductors, clarity cap pur caps, mundorf m-resist 20W resistor.

[eb15]

Snell K bookshelf speaker rebuild with the inexpensive Dayton DA215 aluminum cone woofer and seas 19tffc 3/4" tweeter.
I prefer the seas 3/4" here to the current peerless D19. worth the upgrade cost here replacing aged and slightly defective tweeters.
Using original inductors. Replace electrolytic cap stacks with Jantzen Z-standard 10uF.
The relatively inexpensive Jantzen Z-standard caps works extremely well here.
A preferred balance of sonic characteristics with these drivers, and convenient size, standard solid core leads, etc.
Change out adjustable resistor in tweeter circuit to Mundorf MResist 20W fixed 8.2ohm wired after inductor.

[eb15]

Snell K rebuild rev 2
tweeter attenuation resistor position moved to original and tweeter phase inverted (though not showing up here)
overall slight spectral tilt downward into the treble is a pleasant 'recessed behind the speaker's front plane' sound,
reducing the tweeter pad to 6.8ohm should be flatter but sounds 'forward' in a way I don't like.

[technodanvan]

Started project to rebuild a snell type m cabinet with current drivers, and crossover parts.
An initial Type M redesign. Snell Type M cabinet is 7.5-in wide 11-in tall 5.5-in deep.

Is that right, only 5.5" deep?

[Reet]

There's some major phase issues in your measured data..Can you not see that? Are you using a real mic or USB?

https://kimmosaunisto.net/Software/VituixCAD/VituixCAD_Measurement_REW.pdf

[eb15]

Is that right, only 5.5" deep?

Yes for the little Snell M cabinet (grill removed)
and the Snell K cabinet (grill removed) measures 18.5"x11"x 7.5"

There's some major phase issues in your measured data..Can you not see that? Are you using a real mic or USB?

I did say (poorly done) meaning I haven't taken the time to read and comprehend all the docs for Vituix or REW.
The JBOX supplied microphone is a Panasonic electret powered by the externally powered JBOX USB soundcard/amplifier/mic amplifier/switcher box which also measures impedance.
I hope this link works... https://www.aliexpress.us/item/3256804492315518.html

just a quick measurements using the SPL sweep signal in REW in a crowded family room probably containing lots of reflections.
This was good enough for the basic response trends and distortion.

I hope to do more optimized measurements in the future.

[Reet]

I did say (poorly done) meaning I haven't taken the time to read and comprehend all the docs for Vituix or REW.
The JBOX supplied microphone is a Panasonic electret powered by the externally powered JBOX USB soundcard/amplifier/mic amplifier/switcher box which also measures impedance.
I hope this link works... https://www.aliexpress.us/item/3256804492315518.html

Neat, a commercially made measurement jig from China, with integrated USB audio interface. I'd question the quality of the audio interface and mic/calibration, but otherwise is a cool product, and perfectly usable for dual channel measurement with REW or ARTA.

just a quick measurements using the SPL sweep signal in REW in a crowded family room probably containing lots of reflections.
This was good enough for the basic response trends and distortion.

Reflections and lack of response processing is one thing, major error is timing/phase between woofer and tweeter. Tweeter looks like its a meter away from the woofer. This makes posts above with crossover design just useless information.

[eb15]

The redesigned snell k distortion measurement with da215-8 woofer and seas 19tff tweeter.
I wanted to use up these drivers I had on hand and try to be as 'drop in replacement'
for the original driver cutouts and crossover circuit.

As can be expected the Dayton da215's distortion bump comes through in the complete speaker measurement.
overall response is reasonable.
You could do better distortion with either the "designer series" DSA215-8 (slightly more efficient)
or the Dayton RSS210HF-4 (less efficient) for a two-way speaker.