Questions for Peter

Masterlu · #1 (**permalink**) 05-13-2009, 10:23 AM

Post any questions for Peter from Symposium Acoustics here.

magnmac · #2 (**permalink**) 06-13-2009, 09:10 PM

I noticed some Fat Pads under a Krell CD player; but I thought rollerblocks were suggested for sources? Which should one try?

Masterlu · #3 (**permalink**) 06-13-2009, 10:15 PM

I prefer Rollerblocks for my sources.

streetspirit · #4 (**permalink**) 06-14-2009, 01:57 AM

how much do the Isis racks retail for roughly?

Masterlu · #5 (**permalink**) 06-14-2009, 02:03 AM

Quote:

Originally Posted by streetspirit

how much do the Isis racks retail for roughly?

They are all complete custom creations, they run many thousands of $$$

I have sold about half a dozen or so.

streetspirit · #6 (**permalink**) 06-14-2009, 02:14 AM

wow, i was checking out their website and was curious!

jprice · #7 (**permalink**) 08-19-2009, 07:49 PM

I am very successfully using Svelte shelves under a pair of Avalon Eidolons - The Sveltes make a significant difference in "tightening up" the sound, giving better focus and improving the soundstage. I have used them both with and without roller ball II's.

In a second system i am using a pair of Sonus Faber Guarneri Mementos with the dedicated granite base stand. Would a pair of Svelte shelves be appropriate in this application?

Thanks

TommyC · #8 (**permalink**) 08-20-2009, 03:28 AM

Quote:

Originally Posted by jprice

In a second system i am using a pair of Sonus Faber Guarneri Mementos with the dedicated granite base stand. Would a pair of Svelte shelves be appropriate in this application?

Thanks

I would like to know this too. I don't recall seeing any pic of the GM sitting on another board.

Symposium · #9 (**permalink**) 08-20-2009, 05:22 PM

Hi Guys,

Your question is interesting because it illustrates one aspect of how the Svelte works with loudspeakers - its main function is to damp resonance and vibration in the loudspeaker cabinet itself, and as long as the speaker cabinet is contiguous - that is, is one entire piece enclosing a particular loudspeaker driver or drivers (such as a woofer, midrange, etc.), then the Svelte works best in direct contact with the speaker, as shown on our website at the bottom of the "Svelte Shelf" page. Benefits include better top to bottom musicality, "cleaner" base, greater dynamics, and midrange bloom. Sometimes, the improvements will be almost "jaw dropping" if conditions are ideal!

However, there are exceptions to all rules and soon after the Sveltes were introduced, we at first were a bit puzzled that although the Sveltes worked great with nearly all speakers, there were cases in which users noticed a change in the overall speaker character (while hearing other advantages) which caused them to be dissatisfied with the overall result. Examination of this problem revealed that in all of these "exceptions," what was different was that the speakers in question had a dedicated base that is separate and distinct from the main speaker cabinet. This base could be like a plinth that fits around the bottom of the speaker, or separated by cones or some other structure from the main body.

Why should this make a difference? Whenever there is a dedicated base that the speaker designer has included in his design, this base will contribute to the overall "sound" of the speaker. In other words, it's part of the designer's "voicing," if you will, of the cumulative effect of all the aspects of the speaker's makeup. Now, most bases (and this certainly includes granite) will have some kind of "resonance" or effect - however subtle - upon the rest of the speaker, otherwise, it probably wouldn't be there. So, its function is (other than the appearance) to contribute part of the sonic balance. If you were to put a Svelte flat against such a base, The Svelte will faithfully do one of its jobs, which is to kill resonances- and the quality contributed by the base will be eliminated, or will change. While one will hear improvements in transient response and overall distortion levels even with the Svelte deployed against a dedicated base, the timbral balance of the speaker may change!

We don't want to "second guess" the work of designers - and don't. Therefore, for a speaker like this, I'd suggest starting with the Svelte under the existing base with whatever spikes or cones the speaker came with. This is an exception to our usual "rule" of how to set up Sveltes with most speakers, and by doing this, we accomplish two things: 1) we preserve the original resonant character or quality of the base, since the spikes separate the base from the Svelte and prevent wholesale cancellation of the base's sonic character, and 2) provide a superior "ground" termination for the speaker spikes or cones. The spikes conduct excess energy (one can easily feel this energy circulating in the speaker cabinet by touching the speaker while it's playing) from the speaker cabinet into the Svelte, where it will be absorbed more effectively than if the speaker were mounted on a wood, stone, granite, or carpeted floor. This helps to lessen the amount of vibration in the cabinet which would otherwise be present, since the evacuation efficiency of this energy is increased if a Svelte is used. It's like putting a more efficient heat sink on something hot, which allows it to run cooler. In a way, we're lowering the mechanical "voltage" in the cabinet, which reduces, in turn, the amount of vibration that is being reflected to the loudspeaker drivers, allowing them to put out a purer signal. The result is better sound.

One specific example was a Living Voice speaker which, if used with a Svelte directly under the base with the original spikes REMOVED, made the speaker sound a bit overdamped. However, restoring the spikes and using them directly on the Svelte Shelf made a great improvement - bass tightened, there was less "tizziness" on the top end, and the overall sonic image became more refined and musical, without affecting the speaker's original "character."

I would probably guess that most Sonus Faber speakers will fall into a similar category because of their dedicated bases; therefore, for speakers with bases, we generally recommend that Sveltes be used with the original spikes attached. You can always try it without the cones, and determine which you prefer. Remember, while audio is a science, it's a complex one, and every system (and listener!) is unique. By the way, Rollerblock Jr. may also work as a spike substitute here (and a better one, since it provides benefits that spikes, points and cones can't), but again, should be tested on a per-speaker basis.

Peter Bizlewicz, Symposium

Masterlu · #10 (**permalink**) 08-23-2009, 10:01 AM

Thank you Peter!

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