OT Rubber mounting the speaker

[cradeldorf]

I was thinking the other day as I listened to my speakers resonate my cabinets that maybe if the speaker was somehow connected to the cabinet using a piece of rubber...say 3/8 thick industrial stuff with the white cord running through it. if this would make much of a difference? I googled the idea and found something but I didn't think to bookmark it...kinda sounded like some German high end speaker maker was doing it... You would think it would cut down a lot of the coloration. My 604 C has no gasket and mounts directly frame to baffle while the 604 E has a gasket but I can't imagine it does much since it's screwed down tight to the baffle anyways. What are your thoughts on this idea?

[bowtie427ss]

My .02 would be that the preferred remedy would be to damp/deaden the cabinet via bracing or other methods.

[cradeldorf]

I think this is where I got it from... Down towards the bottom of the page.
http://www.linkwitzlab.com/frontiers_2.htm

[Old Guy]

You don't need anywhere near 3/8 inch.

There are rubber membrane rolls for roofing often about 1/16 inch or so.

http://www.rubber4roofs.co.uk/EPDM-R...Shedcover-EPDM

I used to stop by roofing places and offer a few bucks for scraps...they throw away pieces large enough for us.

[cradeldorf]

Thanks Old Guy, Originally I was picturing mounting the basket of the speaker to the baffle with rubber I'm not sure I would want to risk hanging a 40lb duplex with a 1/16 thick piece of rubber but if your talking the mount the speaker by grabbing the magnet then yes 1/16th would be fine. Which after reading the link I posted I see they were saying mount it by the magnet not the basket. :2thumbsup:

[Old Guy]

I use the rubber between the frame and baffle. I use an adequate baffle the rubber is to seal,

[GM]

As a general rule, about the last thing you want to do with a LF reproducer is 'float' it. The goal is to provide the most stable 'platform' practical for it to do its 'work' efficiently, so ideally it isn't attached to the cab in any way and its design is such that it has no self induced vibrations in its pass-band.

If one looks carefully at an early WE open baffle 'sub' used under the large 15a horns you'll notice that the massive LF driver(s) snuggle up to the baffle, but are not actually bolted to it, instead bolted to a separate, rigid/massive platform or floor.

Later, no doubt to cut cost, etc., for mass production, surround gaskets of the right density to damp any driver induced resonances were developed to allow rigid mounting to a sufficiently rigid/massive baffle.

WRT your 604C, I've never seen a wide BW Altec driver with no mounting gasket, but again, the driver/cab is a system, so if it didn't come from the factory with a gasket, then apparently the assumption was that it would only be used in an Altec approved cab that had taken this into account WRT material, assembly choices.

Note that the gasket design is based on a given clamping pressure, so for max efficiency the specified hardware must be torqued to spec which for most (all?) prosound drivers which I lump Altec into would be based on standard bolt size/thread torque charts which typically is much lower than the average person would hand tighten to.

All that said, if the driver has a high Qts (> ~0.7), then its mounting should be lossy, increasing with increasing Qts to mechanically damp it, effectively lowering its Qts and why those old Motorola consoles with the woofers mounted in individual Styrofoam 'cabs' sounded so good, yet when swapped into a regular cab rang like a 'ten penny nail struck with a ball-peen hammer'.

GM