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gasfan
12-25-2013, 09:53 AM
Just wondering what I might expect from a 2205a this way. I've got a pair but one needs a surround anyway. I don't want to outlay the cost for 2235 kits and thinking a bottom end improvement through the back door could be in order. If there is one, that is ;). Maybe adding some weight? Thoughts?

FE3T
12-26-2013, 08:15 AM
Some of the drivers that have a pleated fabric surround have very soft spiders, in some cases time and use makes the spiders so soft that they very easily develope vc rubbing with a more supple surround. I did replace the surround on a pair of 2206 drivers who arriwed with crushed surrounds with R.Cobb surrounds for 2214`s and one of them seems to have spider to loose to avoid rocking of the whole moving assembly under high volumes. this may of course been caused by stretching of the spider when the orginal pleated surround was chrushed, but be avare that changing the surround might ruin your driver.

siamon
12-27-2013, 09:51 PM
That is a super cool speaker, a 50's driver load hiding in 70's styling. What's up with the one that has an 075 bullet below the lens? I thought it was one or the other, not both.

gasfan
12-28-2013, 12:21 PM
Some of the drivers that have a pleated fabric surround have very soft spiders, in some cases time and use makes the spiders so soft that they very easily develope vc rubbing with a more supple surround. I did replace the surround on a pair of 2206 drivers who arriwed with crushed surrounds with R.Cobb surrounds for 2214`s and one of them seems to have spider to loose to avoid rocking of the whole moving assembly under high volumes. this may of course been caused by stretching of the spider when the orginal pleated surround was chrushed, but be avare that changing the surround might ruin your driver.

Yea, could be an issue. But I found out the underhung vc of the 2205 doesn't allow for the kind of excursion that would be the whole point of the exercise.

Earl K
12-28-2013, 02:33 PM
The 2205a has an over-hung voice-coil ( with an actual xmax of @ 5mm, very much like the 2225 that replaced it ).

The original incarnation, had a triple-pleated, doped-paper, surround ( similar to the 2226 ) with a 30hz Fs ( the Altec 416-8b has a 25hz fs for the sake of comparison ) . The 2205a also had a softer spider than the later "Pro" 2225H transducer .

The original 2205a maybe needed a bit more moving mass ( to give it an mms ) similar to JBL's later HiFi offerings ( like the 2234 or 2235 ) .

FWIW, the original 2205a was more of a HiFi speaker than the later 2225h ( which had been made more "rugged" for Pro use by moving to the double "M" linen-surround, coupled to a stiffer spider ) .

:)

gasfan
12-28-2013, 02:58 PM
Really?:) Well then I guess I'll have to straighten out the source of this ill conceived comedy of errors! Am I to concede that my original notion of re-engineering these is a reasonable one?

Earl K
12-28-2013, 03:44 PM
<<<<<snip>>>>>Am I to concede that my original notion of re-engineering these is a reasonable one?

Yes,

I think you are in Montreal ( yes/no ? ).

Anyways ( if so ), you should solicit some advice ( & parts ) for this project from some-one like Belisle Acoustics (http://tr.ca)( located in/or near Chateauguay, on the Highway-30 bypass / just south of the Kahnawake Mohawk reserve ) .

They ( Belisle ) build transducers from scratch for their own line of speakers ( so they definitely know their way around woofer surrounds & spiders ) .

:)

gasfan
12-28-2013, 05:35 PM
Actually, I'm right in your back yard here in Kitchener. Could I not just sub in a 2235 surround and glue a few rounds of large awg solder wire behind the dust cap? I believe the mass ring on the 2235 is around 35g? But good luck implementing a driver with unknown specs. Are there known T/S for these with a 2235 kit? Or does it matter?