Opinions on possible RM-40 mod

Marbles · « **Reply #40 on:** 24 Mar 2004, 02:41 am »

Quote from: Brian Cheney

As I have pointed out in the past, wool is not reactive enough for lowbass damping but could be just the ticket for mids where the cutoff is around 160Hz.

I'll order some from Madisound and report on any changes.

I think all of us are just using it behind the midrange panels and the FST because it's in the neighborhood.

I am anxiously awaiting your opinion on this.

zybar · « **Reply #41 on:** 24 Mar 2004, 02:46 am »

Yes, as per Brian's advice, I never tried the wool in the woofer enclosures - that was kept stock.

Brian, will be interesting to see if you hear what we are hearing...

George

jgubman · « **Reply #42 on:** 24 Mar 2004, 03:03 am »

Whoops, guess we were all posting at the same time...

1lb of wool per speaker sounds like you're replacing the fiberglass w/ more material than previously existed. Glad to hear this gets good results, I'll have to order some from madisound and give it a try!

I love these cheap tweaks.

zybar · « **Reply #43 on:** 24 Mar 2004, 03:09 am »

Not sure about that...

There was a good amount of fiberglass in the midrange section.

If you do the replacement you will see for yourself.

I kept my fiberglass in two garbage bags in case I wanted to switch back (not sure why I ever would...)

George

audiochef · « **Reply #44 on:** 24 Mar 2004, 03:26 am »

1 lb is per speaker is perfect, I just filled mine as well. It was sounding so good that I logged on to see if anyone else was discussing this and low and behold.

Prior to this I was using polyfill, not as good ,more open than glass , but hollow sounding. Wool actually adds warmth , openess and body. It really is amazing what stuffing can do. I'd have to say the 40s have been upped another notch.

audiochef · « **Reply #45 on:** 24 Mar 2004, 03:47 am »

BTW, I received the new Stereophile last night and was blown away by how the review of the Aerial 20ts mirrored the issues on this circle the last couple of days. Check it out.

BrunoB · « **Reply #46 on:** 24 Mar 2004, 03:29 pm »

Quote from: audiochef

1 lb is per speaker is perfect, I just filled mine as well. It was sounding so good that I logged on to see if anyone else was discussing this and low and behold.

Prior to this I was using polyfill, not as good ,more open than glass , but hollow sounding. Wool actually adds warmth , openess and body. It really is amazing what stuffing can do. I'd have to say the 40s have been upped another notch.

I just ordered a pound of wool too. At the moment I am using Fiberfill from Wall Mart (59 gr/ 626R speaker, one neo panel), which is similar to Polyfill. Audiochef, what brand of Polyfill did use and what amount?

I think that what makes other stuffing fibers better than fiberglass is the random arrangement of the fibers which allows more air between the fibers. Ideally, we would have very thin fibers arranged in all directions as shown here: http://www.poly-fil.com/consumer/cproducts.asp?itemid=fiberfill. This is just a hypothesis, of course.

Bruno

JoshK · « **Reply #47 on:** 24 Mar 2004, 04:07 pm »

Just ordered up some wool so I should be able to report my findings soon too. Why not for so little $$?

audiochef · « **Reply #48 on:** 24 Mar 2004, 04:19 pm »

Bruno,

the polyfill I was using is just called Premium Ultrastuff. I got it from a cragt store.

audiochef · « **Reply #49 on:** 24 Mar 2004, 04:27 pm »

Bruno,

looks to me identical to what you use. It's just not dense enough.

BrunoB · « **Reply #50 on:** 24 Mar 2004, 05:04 pm »

Quote from: audiochef

Bruno,

looks to me identical to what you use. It's just not dense enough.

You are right, it is not dense. It is resilient. So, the trick is to push it, compress it in the enclosure. The enclosure is then completely filled but still contains plenty of air. I compress more at the bottom and not much on top.

Up to now, I tried Acoustastuff, cotton balls, Poly-fil,and Fiberfill. Wool is next.
Stuffing affects the tonal balance and level of the sound coming out of the mid panel. So, you might need to readjust the pods.

I found useful to
weight the exact amount I put in the enclosure. It thing it is important to have the same amount in each speaker.

Bruno

BrunoB · « **Reply #51 on:** 31 Mar 2004, 11:38 pm »

I received the wool today from Madisound. It looks and feels like Polyester fiber stuffing (Fiberfill, Polyfil) - random arrangement of fibers. Quite different from Acoustastuff that was designed to replace wool.

Quote from: zybar

See above...

Close to a 1lb per speaker.

George

1 Lb of wool stuffing per RM40 speaker, that's about 114 gr per neopanel. Seems to be a lot for the 626R mid enclosure. I don't know if the RM40 mid enclosure volume is more than 4 times bigger than the 626R ...

I am thinking also about making cocktails ... one layer memory foam, one layer cotton balls, one layer wool and one layer fiberfill ... same idea as the AIDS cocktail drugs. Each component adsorbs differently.

Quote from: Brian Cheney

As I have pointed out in the past, wool is not reactive enough for lowbass damping but could be just the ticket for mids where the cutoff is around 160Hz.

I'll order some from Madisound and report on any changes.

Brian, any update on the wool stuffing?

Bruno