Need the lambswool mod to experience benefit of new Midwoof?

ctviggen · « **on:** 21 Apr 2005, 08:06 pm »

That's what the instructions imply -- that you need the lambswool mod to experience the benefit of the new mid woofer. I haven't done the lambswool mod, and honestly wasn't going to do it. Is there really that much benefit to the lambswool mod?

warnerwh · « **Reply #1 on:** 21 Apr 2005, 08:44 pm »

Bob: I'm not sure I understand. The lambswool is for the mid panels. The midwoofer/crossover upgrade will definitely improve things without the lambswool being done.

ctviggen · « **Reply #2 on:** 21 Apr 2005, 08:49 pm »

I'll have to copy what the instructions say and put it here. I'll try to do that tonight, when I get home.

Corbin Johnson · « **Reply #3 on:** 21 Apr 2005, 10:38 pm »

I just got my woofer upgrade and read the same thing. I didn't understand it either, but didn't care since I did the lambswool upgrade a few months back.

ctviggen · « **Reply #4 on:** 21 Apr 2005, 10:40 pm »

The instructions state: "You must also have the lambswool update for this update to work properly."

Brian Cheney · « **Reply #5 on:** 22 Apr 2005, 12:19 am »

Yep, the lambswool changes the midrange crossover point by about 1/100th of 1%. Get it from Madisound, $10lb plus shipping, you need 3 lbs for an RM40.

ctviggen · « **Reply #6 on:** 22 Apr 2005, 12:12 pm »

Thanks, Brian. That's interesting -- I had no ideal that internal sound damping/filler could change a crossover point. I'll order the stuff this weekend and put it in next weekend.

zybar · « **Reply #7 on:** 22 Apr 2005, 12:22 pm »

Bob,

I'm sure you will have no problem hearing a 1/100th of 1% change in your system.

BTW, you want to do the lamb's wool regardless of the silly comments on the crossover change. Adding the wool will make a change you can actually hear.

George

ctviggen · « **Reply #8 on:** 22 Apr 2005, 12:38 pm »

Thanks, George. I have heard that the lambswool is a good upgrade, although had I known, I would've ordered it beforehand. I'd like to get everything done at once and finalize my system, as I have so many other things (such as fixing my truck, my spa -- I have a list a mile long) to do, now that the weather is finally turning nice. I'm planning on spending a day or even a weekend fooling around with my system, including my RPTV, and getting everything working optimally so that I don't fool with it -- other than adding acoustic treatments -- for a long while. I've been waiting for the RM40 upgrade, as my midwoofer is blown on one of my RM40s, and I've never really sat down and tuned anything. The subs are really boomy, but I've lived with that because I want to spend the time to do everything right, and not have to do it once and then redo it again a few weeks later. The lambswool may require a change to the setting of the pots, which is what I didn't want to do. Hmmm...I should probably order more lambswool for my RM30C.

Brian Cheney · « **Reply #9 on:** 22 Apr 2005, 03:12 pm »

Lambswool has a different LF absorption spectrum than fiberglass. The relative differences have been published on this board. We move the xover slightly to compensate for this, which is a quite audible and non-silly effect.

warnerwh · « **Reply #10 on:** 22 Apr 2005, 04:06 pm »

Bob: Would you tell us how you blew that midwoofer? The reason I'm curious is I had a pair of Supertower/R SE's with the same midwoofer and ran them pretty hard at times with a Parasound HCA 3500 and never blew anything.

If your bass is a problem then the best thing to do is buy/build some bass traps. You'll be pleased with how much they help. Also AV123's Rdes unit, a parametric equalizer, will be available soon. This piece operates in the digital domain and I am suspecting will help quite alot with many systems. I'll be trying one myself soon.

John Casler · « **Reply #11 on:** 22 Apr 2005, 04:54 pm »

Quote from: ctviggen

The subs are really boomy, but I've lived with that because I want to spend the time to do everything right, and not have to do it once and then redo it ...

Hi Bob,

I think you mentioned that you have been using the X-2 for your x-over?

I have noticed that if I run the SUBs "AND" the mains through it, that the blending and quality of bass is "outstanding" to say the least.

However, if I use it for a "lowpass" filter "only" to the subs, and run the mains full range, it needs a lot more attention to the "blending" and can be boomy if the frequncy/phasing integration is not well adjusted.

Now I have the subs in the same plane as the mains, so I would imagine if you have your subs out of that plane then not only would you need to carefully adjust the "frequency integration", but also the "phase" so that the time alignment/coherance between mains and Subs is not perceptible.

Just a couple thoughts.

ctviggen · « **Reply #12 on:** 22 Apr 2005, 05:33 pm »

Warner, the midbass on my left RM40 began to make a noise a while ago. I do not believe that I did anything to cause the noise. When the noise first started, you had to be right next to the speaker to hear it. The noise has gotten progressively worse, but still is really only bad on certain songs. I do have 6 real traps, two of which are the bass-heavy ones.

John, As for the boominess of the bass, I purchased two Largers and replaced the putty with an 8 inch piece of mortite on each Larger. I've not done anything else, so I'm sure that they're not adjusted anywhere near correctly. The RM40s were also in a different spot from where they are now, and I've not done any adjustment of them, so I know they're also out of adjustment. I do run the RM40s full range and use the X2 to crossover the low bass to the Largers. I've not done any tests as to crossover points, although I did do some level testing. As for phase, phase is really, really hard for me to hear without a helper. I've been waiting to do all this stuff until I get the upgrade and to have a helper. I will do as much of this as I can tonight, then my girlfriend will help me dial the rest of in tomorrow.

warnerwh · « **Reply #13 on:** 22 Apr 2005, 05:44 pm »

One way to adjust for phase is to run your 40's out of phase and adjust for no sound running the subs in phase.

ctviggen · « **Reply #14 on:** 22 Apr 2005, 05:56 pm »

Oooo -- That's a great idea! I wonder if I could do the same trick with my third sub, which I currently have set out of phase to my Largers and use for movies only.