Refoaming speakers - Question on dustcap

[spok]

Some time back I picked up a pair of RTR Model 300D speakers. Each speaker has 2 10" drivers and each driver needs to be repaired. I purchased a new surround kit from Parts Express that came with new dustcaps. My question is this, the dustcaps that are original to the speakers are made of a very light mesh material that you can see through, the replacement caps are a hard plastic. Will using the replacement caps make any difference to the performance of the speakers?

In the past, I have reworked 2 separate pairs of other speakers and the kits I bought did not come with replacement caps and I reused them but they were already a solid material cap. I think it might be hard to reuse and glue the mesh material cap.

here is a look at the resused dustcap on my AVID 230's that I reworked

and the reused dustcap on my Advent 5002's

 

[bobbyrae]

advice I got was leave the dustcap alone

I recently asked a question here about refoaming techniques, and the best advice I heard was to simply leave the dustcap in place. Use a test tone CD to make sure that the cone is centered when you glue down the outer part of the new surround. Many seem to feel this works well.

The reason I had asked my question was largely because I had ran across the type of question you are asking now. Does it hurt the sound to use a different dust cap? Some say yes, so don't change it.

 

[Bigears]

You should be able to re-edge these drivers without cutting the VC caps. Use a 200 hz signal fed into the speaker to center the VC. Works quite well for me.

 

[spok]

good news,

thanks fellas

 

[Sir.Byrd]

You should be able to re-edge these drivers without cutting the VC caps. Use a 200 hz signal fed into the speaker to center the VC. Works quite well for me.

Might want to use a lower tone to run the speaker through its full excursion otherwise you might not notice some high-excursion rub until its too late.

I recently asked a question here about refoaming techniques, and the best advice I heard was to simply leave the dustcap in place. Use a test tone CD to make sure that the cone is centered when you glue down the outer part of the new surround. Many seem to feel this works well.

The reason I had asked my question was largely because I had ran across the type of question you are asking now. Does it hurt the sound to use a different dust cap? Some say yes, so don't change it.

+1 use tones and do not shim. The new dust cap will not work as a replacement for the mesh cap.

 

[spkrdtr]

The purpose of a screen type DC is to vent the voice coil area to keep it cool. Replacing the screen type with a plastic one eliminates this feature and could cause harm to the voice coil due to over heating.

 

[GordonW]

Also, a screen dustcap effectively has no sonic signature... it's pretty close to acoustically transparent. Replacing that with a paper, plastic or other "sealed" dusctap will definitively change the sonics of the woofer, as you've basically just added a "dome radiator" to the center of a driver which did not have such.

You may be able to get by using a felt dustcap in some cases... as they're the least acoustically-active of all others besides screen dustcaps... but it really makes no real sense to change the dustcap type, unless you're SPECIFICALLY trying to MODIFY the speaker behavior.

Regards,
Gordon.

 

[ROSSO]

In my opinion, you don't really need to remove the dustcap to replace the foam surround. The test tone has worked well for me. Really, as long as something is not mechanically adrift, most any low amplitude signal provides enough EMF to center the coil.

If I feel compelled to remove the dust cap, I don't cut it off, I use an adhesive remover (Readi-Strip, IIRC, Lowes, Home Depot, etc) painted around the edge it with an artist's brush, then gently lift it off. Sometimes it takes more than one coat to loosen them. I use the same stuff to remove the old adhesive from the basket rim and cone, then wash it off with alcohol.

 

[archie2]

I would leave the dustcap on for all the reasons above plus the the danger of accidentally cutting the VC leads while cutting the dustcap. Just use a 30 Hz tone to center the VC.