Attention Barry Diament and other speaker isolation gurus!

He has a blog as well, but there is no contact link and comments are turned off:

http://soundkeeperrecordings.wordpress.com/

 

Thanks everybody for the suggestions!
I've tried to mail Barry via his page, but I guess he receives dozens of messages like that per day/hour.
In all the implementations of the bearings I've seen the bearings are held in place just by weight/pressure, so perhaps
I'm unnecesary complicating the things and should cut the threads on my bearings and just put them as they are?
On the other hand custom constuction gives me a chance to optimize the things.

For those interested, a diary of my fight with the rack concept is documented here:
http://www.lencoheaven.net/forum/index.php?topic=11724.0
http://goodsoundclub.com/Forums/ShowPost.aspx?PageIndex=1&postID=19741#19741

Cheers,
jarek

 

Symposium Acoustic Rollerblock Jr's cups are threaded and can be fastened to a support or component. I use them with my loudspeakers and have the bottom cup attached to the stand. It does perform better in that configuration.

 

Thank you John, quite encouraging!

 

Barry still posts here:

http://www.computeraudiophile.com/f12-headphones-and-speakers/

I tried Syposium Rollberblocks +2 which come with small steel plates to place between the base of the equipment and the ball bearing. I simply used sticky tape to hold the plates in place whilst I lowered the equipment onto the balls. Crude but effective. You could then remove the tape with tweezers if you wish and the plates are held in place by the balls.

I would think that some sort of ball bearing device would be beneficial as feet for your rack. I have Finite elemente Cerabase on mine.

I also tried the Rollerblock Juniors which came with top and bottom pieces and a ball, and in my set up I felt that they were better with both pieces, and better than the Rollerblocks +2 with plate. The difference was small but it was there.

 

In Barry's speaker isolation design, the thing I don't get is, are the three ball bearings sitting right on the carpet, with the tile/plywood/speakers on top, but with nothing under the balls, they just sitting "in" the carpet fibers? Aren't the balls smaller than the depth of the compressed carpet? Shouldn't there be something under the balls?

 

No. They are supposed to be something like this:

http://www.symposiumusa.com/rollerblocks.html

The idea is that the balls can move freely in the concave base, that way they can prevent external very low frequencies interfering with the sound from the speakers. The ball and base need to be pretty hard. If the base of your speakers is wood it may also better to put a flat metal plate between the ball and base, as described at the link for the Rollerblocks. In addition, if you think things would be more stable with four balls under the speaker, do that. Or you may feel better doing something like John describes in post 653.

 

Barry's design involves a metal base with a concave cup area, the ball sits in the cup. On top of three (or four) of these bases you use an acoustically "dull" or dead platform like a ceramic tile, upon which the speaker or component rests. The roller bases allow for free, unrestricted micro-movement (which is not possible in designs where there is a cup both above and below the ball).

You can see his in place in this photo (this is his Metric Halo I/O interface):



And the Hip Joints themselves (as he calls them):

 

Good news! Ingress Audio Engineering in Canada is making a roller bearing isolator to Barry Diament's exact specs: 1.5" diameter cup, 0.5" thick (tall), 2" diameter "bowl", 7075 aluminum, and a single 3/8" steel ball (Barry actually uses a 1/2" ball). $90 for a set of three, plus shipping.

 

http://www.ingress-engineering.ca/

 

I thought I would post in here to see what kind of interest there would be for a group-buy of custom machined cups/bowls for use in this kind of application.

I have access to a professional CNC machine shop and the required tools to make these and for cost purposes, making more pieces lowers the cost per piece (this is my personal benefit from doing it as a group-buy sort of thing).

Plan- following the general recommendations of Barry and others:
7075 Aluminum
1 1/2" (1.5") diameter
1/8" (.125") deep bowl
1/2" (.5") thick/tall
Polished to mirror finish
1/2" Chromium chrome steel bearings

Disclaimer:
I would not be doing this in commercial interest. I do not have any professional affiliation or plan to sell these outside of a forum setting. I simply want to have enough made for my own use and if others would be interested in getting some as well, it lowers the cost/piece for everyone involved.

If I can get 72 pieces made the estimated material + machining cost comes out to about $15/piece. I am planning on 36 for my own use which means I would need to have people lined up for 36 more at this price.
$15/piece ($45 per set of 3) + shipping.
Would this be of interest to anyone?

 

I have been working on isolating my Forte 2 speakers, which I had been comenting on in this thread:
http://forums.stevehoffman.tv/threads/im-all-isolated-ed-out-thank-goodness.179658/
I'm cross posting to hopefully get some more info/opinions about the use of granite for isolation. I chose to use granite tiles for isolation as they were a good size 18x18". I banged them and other ceramic tiles with my fist. The ceramic tiles were probably about 1/4" thick and all seemed to ring and then fade to quiet, while the granite tile was 1/2" thick. The granite when struck made a "thunk" sound, and did not continue to ring for seconds. I could not find marble when i was looking that day. It seems like it is universally accepted that marble is a superior product to granite in this application, and I don't doubt this. I will be seeking out marble somewhere down the line, but was curious if there was anything else I should know about when seeking out a replacement for the granite.

 

I'd be in for a couple sets of 3!

 

I've been following this thread, as a guest, since it's inception and thought my experience would pull together some of the insights of this thread and therefore be useful for those who don't want to plough through it. I've had an interest in this topic since I worked weekends for a Naim / Linn dealer in the mid 80's.

In 2008 I'd recently purchased a exdem Townshend Seismic Sink table and it'd greatly improved my system. I'd sold my LP12, by this time but still had my old French table, that had been specifically designed for the deck.

One of my friends brought around his LP12 and we tried it on both tables as he'd been very impressed with the Sink. We both agreed that the old table sounded much better with the LP12!

I met one of my friends, Paul, when he was lecturing in Physics and his thoughts during my whole journey have been very interesting and helpful, his verdict was two suspensions potentially acting against each other was the problem.

The first thing and last thing I bought, of any significance, was Roller balls. I can't remember the make but they cost about £100 for a set. I was so impressed I ended up with 3 sets. These were under my amp and CD player and even though £300 had gone it seemed a worthwhile investment. I didn't try the bicycle inner tube under my speakers due to mad children about! However Paul suggested I try using some thick plate glass I had as base supported by an inner tube underneath my electronics, his reasoning being that nothing would entirely eliminate mechanical energy getting through. He was right it did give another small but noticeable gain. My home at this time had a wooden floor.

When I moved to my present, rented, home and set up my system big disappointment as my system was just off. Lots of newly issued CDs were too fatiguing to listen all the way through. I presumed this was because I no longer had a dedicated mains supply.

As the room where I have my system now is a concrete floor with tasteless imitation wood flooring I put my spiked speaker stands on old Sound Organisation shelf with a piece of camping roll mat underneath. Paul spent a few days here last summer and pointed out that concrete wouldn't stop bass frequencies and wood was probably a kinder flooring. This made sense to me given the liking for maple etc.

Inner tubes greatly improved thing, they supported both speakers and my RELL Stadium III sub.

I then received an e-mail and link from Paul regarding the interesting nature of Bamboo as a less resonant base. Twenty Four pound got me four, I tried one under my HI-Cap. I was blown away, the only thing that'd had a similar effect was going from a Cambridge A60 to my current Naim amplification!

Next I did the same with all my electronics, now sounding as good as ever, bliss!

However my soundstage had opened up so much, after a few days I began to notice some brightness in there. Back to this thread and found Barry's opinion that this would be removed by discarding the metal tops of the Rollers and using a marble base on top of the bearings. I presumed there was some chattering going on, only potential problem was how thick was the sandwich going to get and how much room there is between the shelves of the Sink.

Lots of trying different variables and I've settled on putting two of the Rollers under my Linn Sara speakers for best sound. There's no way I'm buying more Rollers, a New Years resolution, plus I'm delighted with my music.

Of course some people will read this and have doubts about my exuberance. What I can say is that during my recent changes a friend hearing a CD played again one week later asked if it was a remaster. Once he got the idea he'd just ask "what have you done now"?

Of course my solution is greatly influenced by my house but I'm sure you'll benefit massively if you try some of these 'tweeks'.



Hope this wasn't too long!