Putting weights on speakers?

I am trying to adapt this from work.  We used electric motors and bolted them to a concrete base.  The mass of the base was 3-5X the mass of the motor.  The same would hold true for a driver and the enclosure.  If the speaker cabinet is vibrating then that is the resonant frequency.  An accelerometer placed on the cabinet would also tell you what that frequency is.  Another way is to hit the cabinet with a rubber mallet while the accelerometer is attached.  If weight is added to a certain portion of the speaker enclosure that would help but would not solve the resonant frequency for the entire cabinet, I don't think.  It got more complicated with motors if they were mounted on springs, which I think is what you have with a speaker driver.  But in general weight is good, unless you want to move them.

For ~$30:
Reverse some (just longer than speaker to ceiling measure) bar clamps to spread mode. Attach some wood pads to spread out the pressure to the ceiling. Apply fo.Q tape to the pads. It is then easy to apply hundreds pounds of pressure to the speaker assemblies.. AND to remove them if you want soup tonight.
If you have high ceilings live without.

A few months ago I put together a small, simple system while away from home and my TAD Cr-1’s.

The speakers I chose were the LSA statement 10’s from Underwood, which very recently TAS have a great review. I paired them with a Hegel h190 and an old furman power conditioner.

Since the rather small speakers are only 25lbs, I decided to try placing some 8lb neooprene covered hand weights on top.

While the difference isn’t night and day, with the weights on, I get the sense of really listening to a “high end” speaker. Sure I could site a slightly better disappearing sense of the speaker as well as slightly better imaging, but it’s mostly an intangible sense. I wish Steve Stone had listened to the speakers with weights- his review might have been even more glowing.

I especially think with light speakers There is a larger possible improvement (and also 8lbs is almost a third of added mass to 25lb speaker).

I haven’t tried adding weight to my tad’s which are about 130lbs with the attached stands. 

I guess looks don't matter to you ,but they do to your wife.I hope with a 80 lb weight on top of your speakers  you dont have children roaming around ....Really man.or 25 weights.

mglik-

Hi millercarbon,
Thanks for the thoughtful post.
The original design of the Tetra 606 had exactly what you suggest with struts going from the speaker top to the bass cabinet.

Yeah that one's a no-brainer. They will never admit this but its clear to me they got rid of the struts for aesthetics not sonics. 

I admire your deep knowledge and application in your posts and, certainly, your system. I see the very nice concrete block under your TT. Very attractive.

Thanks. The entire rack is my own design. I made the molds to cast the curves. The columns are filled with concrete. Its a modular design, the columns and shelves being bolted together on site. Otherwise the whole rack at 700+ lbs would be too hard to move. 

The top and bottom shelves of cast concrete incorporate sand beds. Concrete and granite are nice and dense and stiff but not very well damped and have a nasty habit of ringing. A layer of sand between them damps the majority of the ringing. Incredibly high damping factor BDR Shelf and Cones takes care of the rest.

The lesson for your situation is its the same but different. Its the same because in both cases, rack and speaker, we want a rigid stable platform. Mass resists motion improving dynamics but releases it back into where we don't want it at rates determined by how stiff and damped the mass is. Stiffness improves transient response but without mass and damping it just vibrates noisily like a tuning fork. Damping lowers the noise floor but sounds lifeless and dull unless combined with mass and stiffness.

Think the Rouge Fitness vest plates will do the job of mass loading nicely. They are almost exactly the right dimensions. 4 plates would only be 1 inch and 4/16ths and they are black.

If you experiment with the vest plates, etc, and listen the combined effects of mass, stiffness and damping will become clear. You will be able to hear it. You will even be able to fine tune your results by tweaking even small things like putting a layer of material between the plate and the speaker. Sorbothane, vinyl, leather, fabric, etc.

Have you thought of mass loading your speakers? My speaker designer didn’t like it when I told him but did respect my ears.

Well, they never do. Anyone designing a speaker knows everything I just explained, and then some. They tried all this same stuff, and then some. They played with wood species, thicknesses, shape, different gasket materials between the driver and baffle, on and on. Then they balance all that against cost of production and consumer acceptance. Finally they have to try and convince buyers the resulting pile of compromises is in fact the absolute best anyone could ever do, period, no matter what. For some strange reason a lot of people buy into this. 

So of course they are not going to like you messing with their masterpiece. At the same time though they want you as a customer. Thus the respect for your ears. Try telling them you sold their masterpiece for Tekton Moabs, see how much they respect your ears then! (That's a joke, btw. But not really.) ;) 

My last speakers were Talon Khorus, and I did think of mass loading them but their tapered shape made it hard to do anything but put more mass in the base, where they were already pretty darn heavy. https://systems.audiogon.com/systems/8367
The Tekton Moabs that are due in a week or so may or may not be another story. Will have to check them out and see. But probably what will happen is, I have gone so far beyond mass loading it would seem like going backwards to be doing that now.