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Millercarbon's Mega Vibration Control Journey

Vibration control is such a huge, and hugely important, topic it deserves a thread of its own. There was a time I thought it nuts to say such a thing. In fact I wrote a letter to the editor excoriating them for wasting my time on the goofy idea that clamping components between shelves could have any effect on sound at all, let alone be worth spending good money on a rack designed to do just that. This was the Michael Green rack, and thanks to my closed mind and dismissive attitude I never did bother to try and find out for myself if there was anything to it.  

Important Lesson Number One: Don't be so quick to dismiss things just because you can't understand how they could work. 

Couple years later unpacking a McCormack DNA1 amp the Owner's Manual says the included spike can be used to improve sound quality. Well now. As crazy as it still sounded this time its Steve McCormack, and he's already given me the spike, so what do I have to lose? Much to my surprise it did indeed improve the sound. Not a lot. But definitely more detail, clarity.  

This is very early 1990's. There is no internet. I know precisely zero audiophiles. Until stumbling upon this one guy at work who says oh yeah and put your CDP on a phone book, and another one on top. Which sounded even crazier but the guy was serious and this being the 90's we all had phone books laying around so I gave it a shot. This time it was only the most barely perceptible improvement, but it was there. If you really listened for it. So not much. Then again, free. Wrapped some fabric around it, ran the CDP like this for quite some time. 

Around this time I'm shopping for components for my new listening room when this guy is more excited about something called Black Diamond Racing Cones than the amp or whatever he was trying to sell me. So I get 3 of these things and they're so much better than the phone book its hard to believe! Well, okay, it was a phone book. Got to compare against something, right? 

These Cones are so good I take them to this Seattle audiophile club and show them around all excited and.... nobody cares. Except this one guy who goes on and on about how he has tried phone books, tennis balls, racquet balls, styrofoam, cones, spikes, on and on everything under the sun, he's tried it all there's just no way he's gonna be impressed- he makes this very clear to me- but okay you're the new guy let me borrow em why not. But they're not gonna work. No way. 

Next day this guy calls me up gushing going on and on how great these are what are they again where did you find em how many can I get? I actually wind up becoming the Washington State distributor for Black Diamond Racing selling Cones, Shelf, all of it. This guy winds up like me, pretty much everything on BDR.  https://systems.audiogon.com/systems/8367  

A lot of what I knew about vibration control back then was based on my own experience with BDR, and learning from owner DJ Casser. This resulted in what became my guiding principles of vibration control: Mass, Stiffness, and Damping.
128x128millercarbon
oldhvymec
5,101 posts
 

millercarbon OP6,501 posts11-09-2020 4:29pmGreat, what I was hoping. So here's my idea: springs between the speakers and the stands. Don't run! Do it like I'm gonna say and they will look almost exactly the way they do now, BUT they will sound a lot better and no more problems with the stands.


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The idea is great, my problem is cutting the pockets. That is apatong wood, (hard) it takes a water cooled bit to cut it.. When I got the legs a mod per leg was, 30.00. I got a hold of the guy to cut the pocket now over 50.00 per pocker 5% accurate. 36 times 50 = 1800.00. There is a one time set up charge of 200, or 250.00. 2100.00 total. LOL the legs were 49-79.00 per set of four...

Shems, inner/outer springs for up and down.. Are the springs your using progressively wound? Tighter at the bottom, than at the top? OR
Same wrap all the way down?

I'll just rebuy and have the mods done and have two set one with and one without.  If I decide to go that way... I can dress the space between the two pieces with a leather seal that will look quite nice, and used often as drawer seals, stops and the like...

I just have think it out.. That is a few quid.. I know the spring aren't that expensive. Getting them in the leg, AND still mounting the leg too. All the mounting holes would be removed by the spring bore. It would take at least 3 screws to secure the leg, or one through the center. More CNC work if I'm not careful..

Suppose I could drag out my duplicating table, for that.. Lot of time... For making gun stocks, guitars body and necks... Cutting weird stuff.. Just need a master to copy from...and add the water cooling pump, hoses, and return tray... I'm an analog guy, what can I say... :-)

Regards
millercarbon's avatar
millercarbon OP
12,531 posts
 
What? Apatong looks exactly like the tight grain reddish brown exotic hardwood in my shop, extremely dense but it is only about as hard as aluminum and can still be cut with router or table saw, you just have to be careful to feed slower. Had mine forever because I hate working with it- one mistake and it takes forever to sand out, if you even can! If you have wood harder than that.... man that's some hard wood! 

Nobsound springs are 1/4" dia and about 1" high. If the speakers are softer on the bottom you could drill 1/4" holes about 1/4" deep and slide the springs in there, however many you need per corner. Only other thing I can think of would be to screw an L-bracket on the side. Wouldn't look quite as good but would only need to stick out 1/4" and you could paint or even cover with a bit of trim. 

Would be nice if you could use springs. They sound better than anything else you could use for this. Or stick furniture felt on the feet and call it good?
oldhvymec
5,101 posts
 
If you have wood harder than that.... man that's some hard wood!

One of the hardest in the world and weathers like Teak.. It is used for wooden decks on wood top low beds and really good steak bed gates.
Wooden legs (when painted) CNC and duplicating sculpture. Yea it will tear up a blade pretty quick, BUT I've used it for years, as trim on baltic Birch. The longer it ages, the more of a chocolate color it turns.. Can't dent it.. Tear a car to pieces with a 1" 24" stick.. Beat it to pieces, LOL

Gotta use water.. It stinks to high heaven too...cut dry.. really stinks...

So the springs are only 1/4" around, that is tiny.. I can bore that with a reamer or a bit...and finish the pocket with flat cutter, shim with 1/4 washers.. That's easy, I was thinking 2-3 inch bore.

Thanks..

Regards
millercarbon's avatar
millercarbon OP
12,531 posts
 
Ordinary 1/4" drill bit, springs fit perfect. Only need to go 1/8" deep, as far as the springs are concerned. If you need to go deeper to have them recessed for looks then drill again oversized so the springs don't rub the sides. 


millercarbon's avatar
millercarbon OP
12,531 posts
 
Getting back on track. The springs I've been using lately are just that, springs. Some from eBay, different sizes, are just plain springs. Nobsound are just springs too, only with caps or footers drilled out to hold them in place. Point being they are all bounce, with no damping. Like Max said his engineering indicates an ideal .16 damping. 

Didn't seem to matter with speakers. Plain springs under the Moabs worked fine. Under the subs, ditto. Even under the turntable, seemed to work fine- at least at first. Got some more, put them under the power conditioner. Speaker cables, power cords and interconnects are on rubber bands. Virtually the whole system is now suspended, one way or another. Not exactly free to move- a lot of the cables are pretty stiff. They will restrict free movement and at the same time feed vibration into the component. Hard to avoid. But for the most part it is all suspended or if you prefer isolated.  

One day I notice this drone or rumble. It happened on a lead-in where there's no signal so I thought it was really bad rumble and my bearing or motor or something was shot. But no. Darn noise would come and go. One time I got up to go check and while walking to the turntable it stopped. Went away. I froze. No rumble. Okay. Went to sit back down, came right back! 

Took a very long time to realize this was undamped resonance feeding back into the turntable. At just the right frequency the system would be excited and with no damping it would feed back and amplify until it was just super alarming loud. 

Even a small change anywhere in the system would stop it, like me moving my weight around the room. Tried different things, the best so far is to add a 5th leg under the table this one with a very small bit of sorbothane that eliminates the feedback.  


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