[ka7niq]

Quote from ka7niq

"Then, the heck with Brians suggestion of removing a 1/2 fingernail of putty at a time.
THAT method assumes we still HAVE fingernails, LOL

The "Ka7niq method" does not make that assumption. "

I need to make sure my wife isn't standing behind me.   OK, the coast is clear.  I asked her to sit and use her superior female hearing to help tune in the passive radiators.  All I really needed was her fingernails.

Actually, I think Brian had a GUY'S nails in mind ?
Womens fingernails are longer, and hold more putty!

[YoungDave]

I just did some measurements.  It turns out that regular string thicknesses of Mortite - straight from the box looks like about 3/16 inch diameter - weighs 8.5 grains per inch, which is 0.55 grams per inch.

That makes the 6-inch length Brian starts with for RM40's 51 grains, or 3.3 grams.

Of note - a quarter weighs 85 grains, or 5.5 grams., equivalent to 10-inches of Mortite.

[ka7niq]

I just did some measurements.  It turns out that regular string thicknesses of Mortite - straight from the box looks like about 3/16 inch diameter - weighs 8.5 grains per inch, which is 0.55 grams per inch.

That makes the 6-inch length Brian starts with for RM40's 51 grains, or 3.3 grams.

Of note - a quarter weighs 85 grains, or 5.5 grams., equivalent to 10-inches of Mortite.

The extra mass of a quarter over the putty would make the speaker overdamped, right ?

Well, I bought my RM 40's used, and they are the older versions.
Turns out, my woofers were leaking!
Perhaps the previous owner got a little too enthusiastic and over excursioned the poor woofers ?
So, a leaking woofer tunes different, LOL

No big deal, my friend is a tech, and is completely re gluing the surrounds.
Brian offered to fix em free, but I can save shipping by having my friend do it local.

[tbrooke]

I'm glad someone finally put the putty weight here. I can't find mortite here and have been using a different product and I was not sure if I was in the same ball park. How did you find the woofer was leaking? I have new megawoofers but I'm worried about the passive radiators.

Tom

[ka7niq]

I'm glad someone finally put the putty weight here. I can't find mortite here and have been using a different product and I was not sure if I was in the same ball park. How did you find the woofer was leaking? I have new megawoofers but I'm worried about the passive radiators.

Tom

A Lack of Bass and I finally heard one rattling!
These were used speakers, and God only knows what was done to them ?
The guy was using a Surround Processor for a pre amp.
Maybe he turned on the Loudness control and cranked up the bass, over excursioning the woofers ?

Even though they were obviously abused, and I am not the original owner, Brian offered to re glue them for free.

You can't beat Brian when it comes to customer service!

[YoungDave]

All (and especially Brian),

Having completed my upgrade to the new midwoofer and CDWG, I find I'm right back where I started - with 51 grains (6 inches) of new Mortite installed, and no idea where the best approximate starting point is.  I assume the new midwoofer will alter the PR response, so it may well be that 6 inches is pretty far off the mark.  If so, it will take a LOT of tiny pinches, and resultant doubt that I'm "finding" it instead of "passing" the sweet spot.

What putty amount do you all start with after making the upgrades?

Cheers,
Dave