Film-Tech Forum ARCHIVE: Question on damaged speaker

This is topic Question on damaged speaker in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=009388

Posted by Marco Giustini (Member # 4544) on 07-03-2008, 04:03 PM:

Hi

Today I found a 2225H with an hole in the suspension.
I know that foam suspension can be replaced. How about non-foam suspensions?

Thanks, Marco

Posted by Steve Guttag (Member # 268) on 07-03-2008, 05:15 PM:

The only solution from an Authorized JBL service center is to perform a "recone" on the speaker. Essentially, the cone, dome, compliance, spider...everything except the metal parts are replaced...it will be a new driver, for all intents and purposes.

Steve

Posted by Marco Giustini (Member # 4544) on 07-03-2008, 06:12 PM:

Thanks Steve.

Yes, I know what a recone is, I thought that perhaps only the suspension could be replaced.

Thanks for your reply

Marco

Posted by Louis Bornwasser (Member # 3063) on 07-03-2008, 07:00 PM:

There are many off-brand sources for that. I have done it myself on smaller speakers. There is no reason not to just buy one and do it. Louis

Posted by Mark Gulbrandsen (Member # 72) on 07-04-2008, 05:49 PM:

If it's a Butyl Rubber Surround you can use Aqua Seal on it. I have repaired several rubber surrounds this way as long as the hole is not too large... not more than a half inch long. Aqua Seal is available at Camping Supply Stores and Dive Shops. I last saw it for sale a week ago at the Zion Canyon Supply Store right at the entrance to Zion Canyon.
Aquaseal Link

Posted by Marco Giustini (Member # 4544) on 07-05-2008, 07:03 AM:

Hi Mark

No, it's not made by rubber. I really don't know the right word for it, but it's the one made by fabric. Oh, it's not a 2225, it's a 2226. Found in 4673B speaker, I read its PDF and found that should be 2225, but the great behaviour to replace broken speakers with something "similar" did the trick [Frown]

Posted by Mark Gulbrandsen (Member # 72) on 07-05-2008, 09:30 AM:

Sounds like you have what I call the "accordian pleat" around that cone.

Mark

Posted by Marco Giustini (Member # 4544) on 07-05-2008, 09:58 AM:

If "accordian pleat" means what I think: LOL

Posted by Steve Guttag (Member # 268) on 07-05-2008, 10:18 AM:

The 2225 has a double roll compliance...the 2226 is a pleated compliance.

The 4673 did indeed come with the 2225 and then the 2226. The cabinet (and crossover) remained the same. The cabinet was the 4507 and the system loaded with a driver was the 4647 and later named the 4647A.

The 2226 is a superior driver in just about every respect to the 2225. The power handling is about double and the frequency response is just as wide and every bit as smooth.

I don't know if I've seen the double-roll compliance sold as a separate part (anular ring). Two things that will fight you on replacing it as a part...keeping things centered being the primary one. Foam surrounds are a bit more forgiving as they don't apply too much lateral support...that is not the case with the cloth surrounds...if you don't get things precisely centered, the compliance will fight against the spider and cause a rub.

Steve

Posted by Marco Giustini (Member # 4544) on 07-05-2008, 10:36 AM:

Thanks Steve

Nice to hear that that cone belongs to that cabinet! I just found the 4647A exploded view only on jblproservice.com, was not available on jblpro.com, only the original 4647. The only odd thing is that JBL is listing the 4647A with the same power specs of the 4647. Is the 2226HPL listed there the same 2226H I have?

4647A

Thanks Steve and Mark.

Posted by Steve Guttag (Member # 268) on 07-05-2008, 09:39 PM:

The reason is the crossover...a 4647(A) presumes a crossover (Though it shouldn't). It was the 3115 for the 4673(A). The spec sheet even said the crossover was 1200Hz...which really is a maximum, not typical. For the 4671 system, which also used the 4647A cabinet/driver it would have been a 3110 (800Hz) crossover.

In fact, at 4647A set up for bi-amp with a 2226H has a continious pink noise spec of 600-watts.

Note, the crossover thing also bit the 4648A-TH...which eventually became the 4638-TH since it had the same crossover. The limiting factor was the crossover, not the drivers...so JBL made the 2035H drivers which look identical to the 2226 but are only 3" voice coil drivers and don't have the power handling (or response) of the 2226.

Steve

Posted by Marco Giustini (Member # 4544) on 07-06-2008, 06:06 AM:

Very clear.

Thanks Steve.

Marco