Better Than Cones/Sex

[mrfeedback]

Today I visited an auto wreckers and scrounged for free a handfull (6) of engine valve springs in order to repeat an experiment that I performed around ten years ago.
This experiment is to mount the loudspeakers on 3 automotive valve springs - 1 spring under each of the bottom front corners of the cabinet, and 1 spring centrally at the rear.
In my workshop I have a pair of Canton GLE-100 3 way (German made and all diecast and Canton branded drivers, heavy, dead and fibreglass mat filled rounded corner cabinets, nice cardboard cone 12" with vulcanised rubber convex surrounds, 2" soft dome mid and 3/4" soft dome hf ), placed at shoulder height on my 10m long quite solid equipment shelf.
A look at my workshop will give an idea - the photo is out of date - those speakers are 6 1/2" 2 way Boston A40 speakers and different amps and source items presently.
Nowadays I am running a 120W+120W DC coupled Jap (old Akai high end) power amp with an outboard 2 transformer/4 isolated DC rails power supply box, 10 pair telephone wire speaker cable, fed from whichever source component via a signal transformer isolation box with reversing switches feeding the primaries so that I can choose final absoloute polarity.
I have tried cones, wooden drawer handle knobs placed either way up, 2cm diameter glass marbles each placed on an o'ring to stop them rolling, soft and hard foam, black rubber and clear rubber pads, carpet pads etc etc in the past in order to explore the loudspeaker mounting options.
It has only taken me 10 years to get a round tuit to confirm my opinion and experience of back then - my knowledge, experience and criterion have changed since then of course, but in this case they still agree.
I confirm that I am getting reduced mids distortion and an overall cleaner, quieter, and more relaxed sound signature, more efficiency, more tuneful bass, more tuneful vocals and more tuneful highs that are very nicely amenable to tone control enhancement/tuning on both my workshop SS system and home Pc/Vcr/Tv/Audio work/play/learn station15W+15w all tube reciever and those Boston A40's.
I typically long term listen to these systems in nearfield, but I regularly go for a sound check walk around including going outside, and this reinforces my nearfield findings.
An additional benefit of this mounting arrangement, both in my past and now recent experience is much reduced coupling into the surface that the speakers are mounted on which results in much reduced acoustic feedback to source devices on the same surface.
I find the dynamic characteristics to be sonically nicer nearfield and farfield - tomorrow I'll go and cadge some more of these springs and try them under the electronic equipment and see/hear what I get.

Eric.

[MRehorst]

What engine size(s) and which cylinders did those springs come from? How many miles were on the engine(s) when the engine(s) were taken out of service?



Cheers!

MR

[mrfeedback]

Originally posted by MRehorst
What engine size(s) and which cylinders did those springs come from? How many miles were on the engine(s) when the engine(s) were taken out of service?



Cheers!

MR

- Didn't ask, don't know, don't care - they were free for the asking. ....and they have more .

Eric.

[Thatch_Ear]

Do you still have your speaks sitting on a shelf? Is this an isolation from the shelf to keep it from becoming a transducer exersize?
You still going to try the silly putty?
And since you seem undaunted by convention like myself I will pass on a tip I picked up last week from a pro installer. This is for his system not his clients. He uses under gear that is not prone to picking up harmonics like SS amps a very dense material that does not pass vibration instead of something soft to absorb the vibration. You might want to get some to use as feet/bases for the springs.
Hockey pucks.

David

[Circlotron]

Is that a toilet paper dispenser I see under the bench? Serves you right for working on domestic electronic stuff.

GP.

[mrfeedback]

Graham, yep well spotted - good for getting lollies and semi eaten biscuits out of videos.
And that mongrel black grease off ya fingers.
I also clean guides and head drums with it.
Another advantage is that you always have a extra roll for when you run out of it in the other room.

Eric.

[annex666]

Springs under your speakers?

Ok this sounds crazy to me, I thought the idea was to damp vibrations rather than to couple them?

What happens when the springs reach resonant frequency?

2PI*ROOT(M/K)

...and the overtones of that frequency?

This is strange, I can truly say I've never heard of this being done before!

[mrfeedback]

Annex, I find the overall sound to be bigger, nicer and more dynamic by allowing the box to 'float' on 3 springs.
Mids are nicer and efficiency is improved in the two systems currently using these springs.
My bass is now going lower and more open sounding, and resonance of the springs does not seem to be a problem.

Try it and you might like it.

Eric, The Trendsetter.

[planet10]

Originally posted by annex666
Springs under your speakers? ... I can truly say I've never heard of this being done before!

I am sure that the resonant frequency of the spring/speaker mass will come into play. As to previous use, the PEARL PR-2 used springs to mount the tweeter pod so as to decouple it from the midbass enclosure. I'll see if i can dig out his white paper and check to see if it has any concrete info.

dave

[navin]

when i had a turntable I used to find this was a good way to isolate it.