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Isolation cone in lieu of rear floor spike

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mentorron

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After owning my original Aerius speakers (manu. date 06/93) for quite a few years now, I finally came upon a resolution to my issues with stridency and soundstage depth. As it may be a placebo effect and disappear with time, I will update this post if/when that happens.
I was experimenting with the setting (height) of the M/L rear floor spikes, which I have done from time-to-time over the years as the listening room changed from house to house. This time I remembered I had some isolation cones which I bought to isolate a CD player I no longer own. I removed the rear spikes and replaced them with the cones.
My initial impression is that the cones seem to have three beneficial effects:
better soundstage depth;
less stridency in strings;
tighter bass.
If anyone can explain this to me, I would appreciate it as I wasn't really expecting very much, if anything, from the swap.
The cones are not fastened to the speakers, just held there by the weight of the speakers. I set them at the point where the spikes screw in. The speakers are on wall-to-wall carpeting over a foam underlay set on a skim concrete floor (in-floor heating system).
( photo of spike and cone attached. )
 

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Gordon Gray

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Apparently, the cones are more effective than the spikes for purposes of "decoupling" the speaker from the floor.

Given my experience, this is not a surprise and what you describe is consistent with my observations in the past.

I would definitely question the "coupling" of the cone to the bottom of the speaker and how it impacts the speaker rigidity thereof.

Ideally and IMHO, cones that are tightly attached (threaded) into the speaker base and then something (I use BDR pucks) to decouple that speaker / cone assembly from the floor is the best combination.

Cones with threaded inserts are readily available from various sources.

GG
 

mentorron

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Thanks for the prompt response, Gordon.
Unfortunately, I am not in a position to upgrade my system any more. The M-L's were the start and end of it while I was gainfully employed (prior to forced retirement). As they are front-ended by mid-fi equipment, which I never had the chance to upgrade, I am happy that a no-cost (to me) change seems to be giving them new life.
Below is another view of one of the cones. It has only double-faced tape for fastening and an adjustable height tip. They were bought at a high-end audio store at a clear-out sale (don't know original price or make) around the same time I bought the M-Ls.
-----------------
My front-end is simply:
a Philips CD-614 player ( TDA1543 / CDM4/19 );
Rotel RSP-960AX processor/preamp (Stereophile Class D);
Onkyo T-401/R1 tuner;
Adcom GFA-6000 5 channel power amp;
---
Monster 400 interconnects/ 1 meter: CD-preamp
Omega oxygen-free interconnects/ 2 meters: preamp-power amp
Radio Shack 12 gauge speaker wire/ 3 meters (bi-wired)
-speaker wires terminated with Radio Shack gold-plated banana plugs / spade lugs.
 

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kach22i

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After owning my original Aerius speakers (manu. date 06/93) for quite a few years now,
I've had mine about as long, a pair from the first couple hundred they made.

I have the upgraded large spikes from M/L, they are a worthy upgrade but there are cheaper sources for similar.

My speakers are tilted up about as fars as they go, partly because they sit three inches off the floor. The extra height is not a good thing, I have to sit upright or lay a folded blanket on the couch (I'm a short person which does not help).

My cones sit on 1/2" x 12" x 10" steel plates (scrap yard). The steel plates sit on homemade sand boxes similar to what Brighstar used to make.

The energy is attentuated and absorbed in my set-up. I feel that decoupling may feed back energy back into the bass cabinet and color the sound in high energy passages.

Scrap metal and scrap wood (painted black), plus play sand and you can have much fun experimenting.

The down side is that my wife has stubbed he toes on the covered sand boxes many times. They increase the footprint of the speaker, as they designed to large enough for equipment 2-1/2" x 17" x 19" .

Without the steel plates too much energy gets sucked out of the music. The sand boxes prevent the sprung wood platform floors from singing along.

Check out my sig, and the System 42 link.
 

mentorron

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Hi George:

Lucky you to be able to make those mods. Any I make have to be invisible to the casual visitor. ( low WAF ;-)
However, so far so good with the cones. If I ever win a lottery I will do some serious electronics upgrades.
Thanks for the tips though.

Ron
 

raanan

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Polycrystal cones under my CLSs gave a fuller,smoother sound with increased midbass.
Some of the stock spikes that come with ML speakers are very thin sounding.
I get good results with ETC spikes.
 

mentorron

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Glad that at least several owners have had similar experiences to mine. So either I'm still sane or we're all "hearing things" ;-)
As long as no one starts calling us Coneheads...although now I guess I can't consider it an insult ;-)
 
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