Woofer surround question

[ngccglp]

Hi,

will changing the surround of my 2245 from foam to accordion cloth surround improves the bass response I.e. tighten up the mid bass? Will I loose the low bass extension?

Thanks

[zeljkor]

While I was searching for 2245 for my project I saw couple of these drivers which were changed this way. I must say I was not happy. While I can not say much about sound of these I can tell you how they looked. From examples I saw it was not possible to put accordion surround in gap where foam was , so I saw that someone had cut precious original cone of 2245. On the second place I was informed that this will pull voice coil out of center of gap a little (up or down) so maybe it will be necessary to change position of voice voil in regard to cone. Also TS parametars where changed so much in non predictive way (fs goes up etc...). Taking all this in mind I would in your case buy c8r2240 and try. In that way you have old cone intact and can use it later. I am sure you will lose deep bas extension. Hope this help.

[ngccglp]

Hi, there is a type of fabric surround that is twin roll and I think will fit nicely. But I think the fs will go up and the original box tuning will be off...

[Earl K]

Hi,

will changing the surround of my 2245 from foam to accordion cloth surround improves the bass response I.e. tighten up the mid bass? Will I loose the low bass extension?

While I was searching for 2245 for my project I saw couple of these drivers which were changed this way. I must say I was not happy. While I can not say much about sound of these I can tell you how they looked. From examples I saw it was not possible to put accordion surround in gap where foam was , so I saw that someone had cut precious original cone of 2245. On the second place I was informed that this will pull voice coil out of center of gap a little (up or down) so maybe it will be necessary to change position of voice voil in regard to cone. Also TS parametars where changed so much in non predictive way (fs goes up etc...). Taking all this in mind I would in your case buy c8r2240 and try. In that way you have old cone intact and can use it later. I am sure you will lose deep bas extension. Hope this help.



Thanks

- As pointed out , this is just a very bad idea .

- Chose your path here wisely.

- "Experiments" like this can easily lead down the path to one being "tagged" as a bogus eBay seller ( which happens when one tries to off-load their failed monstrosity onto the un-suspecting ) .

- "Shunning" (http://en.wikipedia.org/wiki/Shunning) soon follows .

- As advised, it's better to simply buy a pair of 2240's

:)

[ivica]

Hi,

will changing the surround of my 2245 from foam to accordion cloth surround improves the bass response I.e. tighten up the mid bass? Will I loose the low bass extension?

Thanks

Hi ngccglp,

I do agree with zeljkor and Earl K that such act would destroy 2245. The only possibility I can imagine here, in order to rise Fs of the 2245, is to put some 'stiffer' AF foam for 2245. Almost all of the AF foam for the 2245 are of such kind, so it is expect-able that instead of less then 20Hz for Fs, You can get about over 25Hz (28~ 30 may be).
May be better solution is to use some mid-bass combined with 2245.

Regards
Ivica

[ngccglp]

Thanks guys for the advice. I came across this picture which prompted my queries.

http://jbl43.com/?pid=39235600

[Lee in Montreal]

A 2245 with accordeon suspension is... a 2240. A very different driver. Choose your poison. Buy a pair of 2240 and compare. ;)

[ivica]

Thanks guys for the advice. I came across this picture which prompted my queries.

http://jbl43.com/?pid=39235600

Hi ngccglp,

As I can understand there are 15" divers ( may be TAD 1603 ), and the question was about 2245 (18" driver)

Regards
Ivica

[gferrell]

I have a 2240 I would trade. It is actually a great music sub.

[ngccglp]

Hi Ivica,

What I meant was if they could do it to the 2235, maybe it is possible to do it for the 2245H?

Thanks

[ivica]

Hi Ivica,

What I meant was if they could do it to the 2235, maybe it is possible to do it for the 2245H?

Thanks

Hi ngccglp,

I do not believe that they did it with 2235.
I think that such "work" on 2245 would destroy it as 2245 driver.
Look at the figure.
Sd(2245) =0.130 m2
Sd(2241) =0.123 m2
TAD was originally made with accordion cloth surround, as 2241, etc

Reagrds
Ivica

[ngccglp]

Hi Ivica,

Thanks for the illustration, I definitely will not do anything that will permanently damaged the woofer.

Just for discussion, there are other fabric surround that may fit, I have seen it before. The picture I have attached in my previous mail is a case in point. It is twin roll, and narrow enough to fit the original foam gap.

Most likely I will experiment with bi-amping and power amps to get the sound I want.

Cheers.