Woofer surrounds, Thiel CS 1.2

71.218.159.197

Posted on December 14, 2013 at 16:55:42

PeterI
Audiophile

Posts: 1435
Location: Colorado
Joined: October 17, 2006

My older Thiel 1.2 speakers have Vifa P17 WJ woofers with butyl surrounds. The rubber seems to have stiffened in recent years, maybe age or environmental conditions, but they don't seem supple as they should be. I am sure the sound is deteriorating as a result.

Is there a way to 'soften' this kind of rubber, a treatment that will make them more flexible?

I can't just replace because replacement Vifa P17 woofers are all 8 ohm, and mine are special 4 ohm. (though I wish I could somehow 'make' these speakers 8 ohm; they'd be more versatile.)

Thanks

Pete

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RE: Woofer surrounds, Thiel CS 1.2

jaynemo

08:09:10 12/19/13

Thanks for tip.

PeterI

09:26:03 12/19/13

RE: Thanks for tip.

jaynemo

09:40:20 12/19/13

...

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RE: Woofer surrounds, Thiel CS 1.2

jaynemo

08:09:10 12/19/13

Thanks for tip.

PeterI

09:26:03 12/19/13

RE: Thanks for tip.

jaynemo

09:40:20 12/19/13

Why not contact VIfa?

unclestu

21:04:30 12/16/13

RE: Why not contact VIfa?

PeterI

11:55:36 12/19/13

I will now argue the contrary position

Ktem

12:00:23 12/16/13

Speaking as a rubber engineer...

jbrrp1

08:00:48 12/16/13

Thanks very much. nt

PeterI

08:06:10 12/16/13

The question isn't about Thiel, it's about

PeterI

13:19:13 12/15/13

RE: Woofer surrounds, Thiel CS 1.2

George S. Roland

09:21:32 12/15/13

No kidding nt

Ktem

12:17:06 12/15/13

RE: Woofer surrounds, Thiel CS 1.2

Inmate51

17:16:24 12/14/13

RE: Woofer surrounds, Thiel CS 1.2

John Elison

17:05:21 12/14/13

Nay on the ArmorAll!

Brian H P

11:16:01 12/17/13

RE: Woofer surrounds, Thiel CS 1.2

PeterI

07:00:43 12/15/13

RE: Woofer surrounds, Thiel CS 1.2, posted on December 14, 2013 at 17:05:21
John Elison Audiophile Posts: 24045 Location: Central Kentucky Joined: December 20, 2000 Contributor Since: January 29, 2004	I wonder if Armor All in the automotive section would help. I've been using it on the rubber seal around the periphery of my turntable's vacuum platter. Just a thought!

RE: Woofer surrounds, Thiel CS 1.2, posted on December 14, 2013 at 17:16:24
Inmate51	"The rubber seems to have stiffened in recent years, maybe age or environmental conditions, but they don't seem supple as they should be. I am sure the sound is deteriorating as a result. " Do you have any data/measurements to back up your assertions, or, is this just what you think?

RE: Woofer surrounds, Thiel CS 1.2, posted on December 15, 2013 at 07:00:43
PeterI Audiophile Posts: 1435 Location: Colorado Joined: October 17, 2006	you know, that's a thought. Would need repeated treatments probably. I handle a lot of speaker drivers, in and out of cabinets, so i know what the rubber normally looks like, and these have clearly become stiffer. A bit of discoloration as well.

RE: Woofer surrounds, Thiel CS 1.2, posted on December 15, 2013 at 09:21:32
George S. Roland Audiophile Posts: 1539 Location: N W Pennsylvania Joined: March 20, 2004	I wondered if you thought to contact Thiel about your question? George

No kidding nt, posted on December 15, 2013 at 12:17:06

Ktem
Audiophile

Posts: 1910
Joined: September 27, 2012

nt

[Edit: I mean I agree with your sentiment, I was not criticizing the notion of _contacting the manufacturer with such a question_.]

The question isn't about Thiel, it's about, posted on December 15, 2013 at 13:19:13
PeterI Audiophile Posts: 1435 Location: Colorado Joined: October 17, 2006	This is not the first time people have seen the hardening of butyl rubber surrounds. It's about rubber surrounds in general, not just Thiel. I can contact Thiel anytime. Their customer service is excellent.

Speaking as a rubber engineer..., posted on December 16, 2013 at 08:00:48

jbrrp1
Audiophile

Posts: 483
Location: Minnesota
Joined: April 24, 2007

If the Butyl is hardening, it would not be likely that you can effectively soften it. Either it is continuing to crosslink (unlikely, but if so, nothing you can do about it), or plasticizers have migrated out of it over time and it is pretty tough to put those back in (elevated temperature soaking in the appropriate plasticizing oil would potentially soften it - - quite a hazardous undertaking for the rest of the assembly!). In general, Butyl has relatively good hardness stability in ambient conditions, so if it has hardened, I would only expect it to be a little bit. Of course, the original rubber formulator could have f'd it up with a bad design...

I'm guessing replacement is your only option, if your supposition is correct. Contacting Thiel does seem logical.

Thanks very much. nt, posted on December 16, 2013 at 08:06:10
PeterI Audiophile Posts: 1435 Location: Colorado Joined: October 17, 2006	nt

I will now argue the contrary position, posted on December 16, 2013 at 12:00:23
Ktem Audiophile Posts: 1910 Joined: September 27, 2012	No. Do not contact Thiel. That is the last thing you should do.

Why not contact VIfa?, posted on December 16, 2013 at 21:04:30
unclestu Dealer Posts: 5851 Joined: April 13, 2010	Also you may be able to purchase replacement surrounds and simply change the surrounds

Nay on the ArmorAll!, posted on December 17, 2013 at 11:16:01

Brian H P
Audiophile

Posts: 1520
Location: Oregon
Joined: December 18, 2012

It may actually accelerate the deterioration/hardening of synthetic rubber by leaching out the volatile hydrocarbons that keep it soft. Particularly in combination with UV exposure. Many people have found that it accelerates the aging and cracking of vinyl dashboards.

It seems to cause no problems on hard plastics like polycarbonate. Several CDs that I shined up with it 20 years ago to eliminate skips still play fine.

RE: Woofer surrounds, Thiel CS 1.2, posted on December 19, 2013 at 08:09:10
jaynemo Audiophile Posts: 1881 Location: Connecticut Joined: February 7, 2003	Send them out and get new surrounds . Done. Simply Speakers in Florida is one option they do great work

Thanks for tip. , posted on December 19, 2013 at 09:26:03
PeterI Audiophile Posts: 1435 Location: Colorado Joined: October 17, 2006	I may do the surrounds myself since finding Madisound sells them, (though not shown in their online catalog). I've done surrounds before. They had stiffened to the point that the rubber didnt spring back when pushed. Pete

RE: Thanks for tip. , posted on December 19, 2013 at 09:40:20

jaynemo
Audiophile

Posts: 1881
Location: Connecticut
Joined: February 7, 2003

They get trickier the tighter the voice coil gap which may necessitate shimming good luck with the project

RE: Why not contact VIfa?, posted on December 19, 2013 at 11:55:36
PeterI Audiophile Posts: 1435 Location: Colorado Joined: October 17, 2006	Vifa doesnt exist as a separate entity. Their European website, Tymphany, isn't helpful to the DIYer. Madisound has the replacement rubber surrounds. cheers

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Woofer surrounds, Thiel CS 1.2

71.218.159.197