Speaker Stand fill material

[The Computer Audiophile]

In my opinion there ideally should be zero resonance from the speaker cabinet and the stand. The most accurate transducers are the drivers not the cabinet.

 

The new Magico Q series loud speakers come as close to this as anything I've ever seen. The new Q1 stand mounted speaker has a solid alluminum stand that is very heavy.

 

[VT Skier]

I filled my Dynaudio stands with "play" sand from Lowe's, about 3/4 full based on John Atkinson's recommendation in his review of the C1s and the Stand4s. I agree with you Chris, why not all the way full? But I figured if I tested, it would mean pouring and emptying and, eventually, a mess, so I slavishly followed the magazine's lead.

 

Some people recommend a mix of lead shot with sand or litter, maybe because they think varying densities are better? I'll try gold dust next time.

 

[elcorso]

Then Chris it should be speaker design dependent and floor material and floor construction type.

 

In my personal case (I'm on Martin Logan's most of my life) they have no problems right know with a solid concrete floor & ceramic cover. I use only the spikes that come with the speakers.

 

But, in my previous home, 4th floor in a condo, "floating" floor with an also "floating" wood cover, the sound was so awful that I tried a lot of speakers stands, and finished with a heavy and thick wood stand, but still with the speakers spikes.

 

If the Magico uses solid aluminum, it's because the designer team determined this is the best for them, in all the posible situations, but should be very expensive.

 

Some speakers manufacturers, in his design, uses wood resonances in his cabinets in order to achieve the sound they want, but this is also driver (transducers) dependent.

 

That's why it is sometimes very difficult to find the "correct" speaker stand, for each speaker and your floor. Or no stand at all.

 

I think it's better to ask the speaker factory, most of them are very helpfully.

 

Happy listening,

 

Roch

 

[SteveChicago]

@ Chris: Lack of resonance may be preferable with certain speakers. However, others, like Harbeths, are specifically designed to resonate and that improves the sound. The cabinets are thin walled and sound best with "breathing room" around them.

 

[The Computer Audiophile]

Hi Steve - Do you know what frequencies the Harbeth's resonate at and if this is more accurate than reproducing these frequencies with a traditional driver?

 

[SteveChicago]

Hi Chris: Wow, that's an engineering question (I'm just a lawyer who loves music). I have not auditioned numerous speakers, but I can say that the Harbeths really shine in the midrange and image very nicely. Vocals, drum hits, and guitar, for example, sound very life-like.

 

Anyway, here's an FAQ from the Harbeth site, which may provide some insight:

 

"14. What is the importance of the cabinet construction, and what is a 'thin wall cabinet'?

 

Everything in the universe resonates, and that definitely includes loudspeaker cabinets! Some resonances are rather useful - such as the fundamental resonance of the air mass inside the cabinet which acts as a spring against the bass/mid diaphragm (cone) and when correctly proportioned, permits a good system bass response. Other resonances are not so useful or desirable, but result from Newton's Second Law of motion: 'every action has an opposite and equal reaction'. For example, as the cone moves inward, the cabinet must, by definition, push back against it, and this sets up peaky resonances inside the cabinet structure which are measurable outside the cabinet with suitable equipment.

 

At the design stage of a speaker system we need to be aware of the contribution of the cabinet walls to the overall sound perceived by the listener, even if not in the system's frequency response curves. At certain frequencies, untreated wood will be so acoustically transparent that sound waves will pass through it from inside the cabinet as if it is almost invisible; at some (and hopefully different) frequencies the combination of the panel's stiffness and mass will encourage it to sympathetically resonate with notes in the music. Taming these panel resonances is extremely time consuming at the design stage, and demands great attention to the smallest details of the cabinet construction, measuring equipment much trial-and-error. Whatever solution one arrives at, the best one can achieve is to suppress a panel's output and/or to steer it into a frequency band where it is either inaudible or benign: this implies at the bottom end of the audio spectrum.

 

It is self evident that if the 'raw' untreated panel is thin, that damping that applied damping will have a proportionately greater beneficial effect than if the panel is thick, where no amount of conventional surface damping can adequately suppress latent peaky resonances. The superiority (although at very high cost) of the 'thin wall' panel philosophy was invented and used by the BBC from the 1960's, backed up by measurements and Research, and is, to our mind, the best overall solution for an acoustically quiet mid band, where the ear is extremely sensitive to buried resonances."

 

HTH

 

Steve

 

[proftournesol]

As I understand it, there are many ways of handling vibration: You can do away with cabinetry altogether and use a dipole speaker (open baffle or planar speaker); you can use light wall construction where the vibration frequencies are known and calculated for in the design; or you can mass load to lower the resonant frequency. Companies like ADAM use double walls with a sand layer in between in their Tensor series, other companies line their cabinets to add mass, other owners couple the speakers to the floor to add the mass of the floor to that of the speaker. This is only helpful if your speakers are on a high mass floor like a concrete slab. Adding mass to the stand will lower it's resonant frequency, this may or may not be helpful for the overall sound depending on the speaker design.