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new member. Am using Carver speakers only.

Posted: Sat Mar 07, 2009 7:02 pm
by Garyspang
Have studied the lengthy carver patent for ribbon speaker construction. But am still not sure how to get the occasional buzz out. Any suggestions?

Re: new member. Am using Carver speakers only.

Posted: Sat Mar 07, 2009 8:39 pm
by Reese
Welcome aboard! Try the search function here for ribbons, buzzing, etc. There have been several threads in this forum about various causes (from humidity to broken mylar/kaptan) and fixing those annoying (or scary) buzzes

Re: new member. Am using Carver speakers only.

Posted: Sat Mar 07, 2009 9:49 pm
by engtaz
Welcome Garyspang. Toymaker and DaveS are the experts on all that are ribbons.

Re: new member. Am using Carver speakers only.

Posted: Sat Mar 07, 2009 10:04 pm
by DaveS

Re: new member. Am using Carver speakers only.

Posted: Sun Mar 08, 2009 12:02 pm
by Mr. M-500t
Are you sure the buzzzzzz is originating at the ribbon or is the ribbon just revealing it ?

Re: new member. Am using Carver speakers only.

Posted: Sun Mar 08, 2009 12:31 pm
by Garyspang
I am sure it is the ribbon.
The long ribbons are used presently in a minimum baffle as stand-alones along with a DOMINATOR D-10 subwoofer. The original woofers blew all the foam surrounds to shreds watching MATRIX 3, have replacement woofers in boxes, ready for installation.
Thanks for the numerous suggestions. I will need some time to act on them.

Re: new member. Am using Carver speakers only.

Posted: Sun Mar 08, 2009 1:22 pm
by OBI56
Garyspang wrote:I am sure it is the ribbon.
The long ribbons are used presently in a minimum baffle as stand-alones along with a DOMINATOR D-10 subwoofer. The original woofers blew all the foam surrounds to shreds watching MATRIX 3, have replacement woofers in boxes, ready for installation.
Thanks for the numerous suggestions. I will need some time to act on them.
You ARE using them with the Carver crossover or suitable electronic active crossover, right???

Re: new member. Am using Carver speakers only.

Posted: Sun Mar 08, 2009 3:09 pm
by Garyspang
Yes

(The buzz was there before I disassembled them from the original baffle and cross-over)

It is a very sharp digital high-pass filter similar to the analog Chebechev type without the phasing problems. The low cutoff for the ribbons is set for 100 Hz and the high cutoff for the subwoofer is set for 100 Hz.
The high damping factor of the amplifier gives the ribbons a smooth response, so that any resonances are not noticed by me.
The present work-around is the use of a center speaker (Klipsh, yes with a horn) so that speech and singing is not exiting the buzz. A lot of spacial imaging and some sound quality is lost as a tradeoff. The system is equalised automatically for a flat response with mike feedback to the amplifier

Thanks for your interest.

Re: new member. Am using Carver speakers only.

Posted: Sun Mar 08, 2009 5:19 pm
by Toy Maker
None of the Carver ribbons are designed to go below 150Hz, you have them crossed way too low. That might be part of cause of the buzzing. If the ribbon is moving more than it is designed to you could be over stressing the kapton, which will in time stretch the mterials, to where they are loose, and WILL buzz... and or, the kapton is hitting he magnets inside if it is moving too much
Change your crossover point to 150 or 160hz.
I am betting the reason you did this was because the max crossover point for the sub you are using is 100hz...

NOT a very good matching driver... sorry

Re: new member. Am using Carver speakers only.

Posted: Sun Mar 08, 2009 5:25 pm
by stevewithrow
Toy Maker wrote:None of the Carver ribbons are designed to go below 150Hz, you have them crossed way too low. That might be part of cause of the buzzing. If the ribbon is moving more than it is designed to you could be over stressing the kapton, which will in time stretch the mterials, to where thay are loose, and WILL buzz... and or, the kapton is hitting he magnets inside if it is moving too much
Change your crossover point to 150 or 160hz.
I am betting the reason you did this was because the max crossover point for the sub you are using is 100hz...

NOT a very good matching driver... sorry
Toymaker is right on about this , my ribbons cross at 150 HZ then roll off every thing alse to my sub . I believe along time ago Carver did at one point cross at 125 , but found this DID stress the ribbon .

Re: new member. Am using Carver speakers only.

Posted: Sun Mar 08, 2009 6:33 pm
by TNRabbit
Garyspang wrote:I am sure it is the ribbon.
The long ribbons are used presently in a minimum baffle as stand-alones along with a DOMINATOR D-10 subwoofer. The original woofers blew all the foam surrounds to shreds watching MATRIX 3, have replacement woofers in boxes, ready for installation.
Thanks for the numerous suggestions. I will need some time to act on them.
Are you planning to put them back together in the original configuration? What woofers are you replacing the originals with?

Re: new member. Am using Carver speakers only.

Posted: Sun Mar 08, 2009 9:50 pm
by Garyspang
The replacement woofers are WP1220 from Dynavox.
I have enough for two platinums and two silvers.
If I ever find my original hardware (angle brackets and screws and new binding post mounting plates) (the original plates cracked beyond use for no good reason) burried in a box somewhere, I will reassemble them.
But first a permanent fix for the occasional buzz has to be found. Several suggestions given already will be tried. Thanks.
The original patent describes the factory assembly procedure in detail, but it has no hints what to do if a problem develops. Kapton is a fantastic high temperature insulating film that can tolerate the insane high power and associated heat generated by the ribbon conductors. I want to keep it.
I will do a frequency test and find the buzzing frequency and spot. Then I have to find an old GENERAL RADIO (GR) stroboscope, syncronise it to the applied frequency and watch the bad spot in slow motion under the GR strobe light. This will show me the exact problem. Maybe then I can figure out a permanent fix. If you know of an old GR stroboscope please let me know.
Sorry about the wordlyness of my reply, but the subject is very important to me. Great stereo or surround sound is hard to find. Carver found it for me.

Re: new member. Am using Carver speakers only.

Posted: Sun Mar 08, 2009 10:16 pm
by Toy Maker
Don't mean to sound too cut and dry, but they just get old and warn over the years...
Think of it as "re-coning"

I won't suggest taking it apart.

The best thing you can do is have DaveS rebuild it/them for you...
They will be as good as new.

Re: new member. Am using Carver speakers only.

Posted: Mon Mar 09, 2009 2:50 am
by Garyspang
Thanks,
That is the best suggestion I had so far. Will have to find out if DaveS uses KAPTON and if it is reasonable in todays enviroment. Only found someone in FL doing this, but he did not use KAPTON. This bulletin board is very slick, have to find out how to get a private message to DaveS. Discussing business in public is not my style.

Re: new member. Am using Carver speakers only.

Posted: Mon Mar 09, 2009 5:17 am
by TNRabbit
The "SOMEONE in FL" is DaveS or Toy Maker. They are the only ones on the planet that repair ribbons, so my knowledge. And yes, they use KAPTON.

Also, what the heck is that in your avatar???


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