My Mass Rings Arrived!

[herki the cat]

I pulled one of my JBL 2235Hs from the cabinet and the inscribing on the back has 2235Hs plus serial number:50320. I need to replace the domes. I will confirm if the rings are present.

Looks like you are on the verge of working out the rest of your speaker design which will require enclosure frequency response measurements.This will necessitate covering up that entire tile floor with a wall to wall thick rug, which for good sound absorption should have a wall to wall under-pad of "Ozite"-- Brand Name," wool & cow hair construction. This is the material used by Dr Harry Olsen on all six sides of the RCA Princeton Laboratories Anechoic $1,000,000 quiet room. For the treatment on walls & ceiling, please consult member EarlK's recent excellent LH Forum threads & posts on this subject.

The JBL tube of C.P. Moyen Inc., cement shown in a recent thread uses Acetone solvent which is similar to MEK solvent. Both of these solvents have fumes which will cause the foam in the motor pole piece vent hole to revert to a gooey mess of liquid polyurethane that will find its way to the voice gap.

It is suggested you should call C. P. Moyen Inc., Customer service @ 874-673-6866 to explore an RS Cement of toluene solvent compatible with foam, paper cones & caps. BTW, Toluene IS compatble with foam surrounds.

herki

[Loren42]

Looks like you are on the verge of working out the rest of your speaker design which will require enclosure frequency response measurements.This will necessitate covering up that entire tile floor with a wall to wall thick rug, which for good sound absorption should have a wall to wall under-pad of "Ozite"-- Brand Name," wool & cow hair construction. This is the material used by Dr Harry Olsen on all six sides of the RCA Princeton Laboratories Anechoic $1,000,000 quiet room. For the treatment on walls & ceiling, please consult member EarlK's recent excellent LH Forum threads & posts on this subject.

The JBL tube of C.P. Moyen Inc., cement shown in a recent thread uses Acetone solvent which is similar to MEK solvent. Both of these solvents have fumes which will cause the foam in the motor pole piece vent hole to revert to a gooey mess of liquid polyurethane that will find its way to the voice gap.

It is suggested you should call C. P. Moyen Inc., Customer service @ 874-673-6866 to explore an RS Cement of toluene solvent compatible with foam, paper cones & caps. BTW, Toluene IS compatble with foam surrounds.

herki

Thanks for the information.

I think that I will try dragging the cabinets outside on a calm day first. Florida is pretty breezy and the next calm day is predicted Wednesday. That is a lot cheaper than a lot of carpet, but in the final room setup we should consider some sort of carpet between the cabinets and the sofa.

Speaking of the final room orientation, yesterday we temporarily moved the room to its new position and set the speakers near the corners. I had a guest over to audition the system (amp and speakers) and he brought some test CDs including Hector Berloiz Symphony Fantastique. We cranked up the system to a good listening volume, which was modestly loud. This CD has a very wide dynamic range and it appears a lot of sub sonic rumble as well. The left woofer found its inward excursion limit on track 5 with a loud sharp whack about 3 to 5 times before I dropped the volume slightly. It was either the voice coil bottoming out or the mass ring hitting the pole (probably the latter). I need to consider a rumble filter.

Nevertheless, my friend was quite excited with the performance. He said that only twice in his life had he ever felt a concrete slab floor vibrate. The first was when he auditioned a pair of B&W 801s and then this system here.

The tube amp never spit out anything offensive for the whole performance. Having extra capacitance in the high voltage power supply really pays dividends when you need serious transients, particularly bass. Seemed to just loaf along.

I'll research the glues.