Fast, fun, Inexpensive OB project

[Bluto]

CLS -

I want to see if those who discussed doing the versions on stands with XO changes or phase plug mods have any success.

Bluto

[mige0]

Though I love speakers with phase plugs especially in OB applications, the main culprit with the otherwise excellent 12" Peerless isn't the dust cup IMO.

Look for a speaker with cloth surround if you can find one with a smooth voice region and such well controlled break up like the Peerless and you will gain way more in terms of less (rubber-like) coloration.

XO has to be re-tuned as is the case of removing the dust cup only as this plays a important role at the high frequencies the 12" is used in this beautiful design.


Greetings
Michael

[MisterTwister]

wooden dowel glued on with epoxy. copper ring is held by screwed on speaker spike.
http://img527.imageshack.us/img527/9871/cimg1327ta0.jpg

[mige0]

Ready for take off - Scotty ?



But to be seriuous - any subjective differencies in sound?

Michael

[MisterTwister]

none noticed yet though there is a difference in measurements.
they may be easier to listen to for prolonged time, but I use these speakers only for movies. they are used ~100-700 hz, so harmonic distortion was never the issue anyway.
This mod is worth doing if you are using this woofer for this thread's project. plus, I think cone/surround treatments would be necessary ( at 700 hz cone starts to go wild).

[MisterTwister]

stripped top damping layer from cone
slit cones
sprayed with damping spray
red impedance curve is before, green curve is after mods

[CLS]

Impressive! 3 peaks between 500Hz to 3KHz are well damped! Amost disappear I should say.

And the low end impedace peak is lower in amplitude and frequency. Is this because of heavier mass? Is it possible to measure this added mass?

[Pano]

Very interesting work. Thanks for posting!

I'll be building a pair of these for myself next week. But I'll be using a different tweeter, the good old ScanSpeak 3806. Recently out of production, but still a great driver.

Don't know if I will go so far as to strip, slit and recoat the Peeless woofer - but it's nice to see someone take this to the Nth degree. =)

[MisterTwister]

CLS, yes, fs is lowered because of added mass.

i noticed that after all these mods there is much less ringing at high volume.
even though there is almost no cone breakup, these woofers still did not sound too good, when played full range. because of large paper cone energy storage I guess...

ScanSpeak 3806 probably can be used just with a single capacitor, for even simpler crossover )

[Pano]

Originally posted by MisterTwister
... these woofers still did not sound too good, when played full range...

Uh, yeah. --- It's a real woofer - maybe even a subwoofer. Never meant to sound good fullrange. But it is quite a remarkable drver for its class and price.

All the more reason to use it, and use it right.