DIY Audio Rack [*fail*]

Seen a few discussions on this topic and wanted to chime in with my experience. A recent amp upgrade necessitated a change from the "Solid Steel" rack I was using. New amp is deeper and taller so I needed a solution to provide deeper shelves and more clearance for ventilation. Didn't see a lot of offerings that were aesthetically appealing enough to motivate me to immediately bust open my wallet, and a few months earlier I built a "live edge" bar height table to accommodate extra seating in my listening room. The table project was fun and turned out very decent and provided the form and function I was looking for. With all this in mind I thought it would make sense to maintain a consistent look and build a rack using the same materials. Form factor of the Solid Steel rack is 3 shelves in 2 columns accommodating 6 components. I was keen on lowering the profile of the new rack as it is situated in front of an 8' casement window with a low sill so I built it using two shelves which are 65" wide to accommodate the width of 3 standard components. 
Materials used for the table and new rack are 2" square steel tubing that I had fabricated by a local welding shop. The shelves are made from 2" thick live edge pine that is milled/finished to ~1 3/4" thickness. I had concerns using pine, but after working with it I prior, it felt heavy and solid and I thought it would have the density to not negatively effect the sound in the room. The rack is located on the front wall between the speakers so I thought that by lowering the profile, there was an outside chance I might even get better sound. Lastly, when I assembled the rack, I isolated the shelves from the frame with 1" wide by 1/4" thick neoprene tape. I also used rubber washers between the screws and the frame so  the shelves and the steel frame are isolated from one another.
Once I got the rack assembled I was more than pleased with the look. I was seriously chomping at the bit to get it situated in the room with components installed but didn't right away because I really enjoyed just looking at the finished product. I recruited my son to help me move it and was really encouraged as the thing is a beast and weighs a lot. 
I installed components into the new rack, powered everything on and gave it about 30 minutes before I queued up the first song. I think I was still interested in how great it all looked when the music started but it didn't take more than several seconds to realize something had changed and I don't mean just a little. It was like someone put a blanket over each of my speakers. It seems that aside from building a fine looking rack, somehow I also succeeded in building a broadband attenuator that does an awesome job of damping most of the audio spectrum in my room and is particularly harsh on low and mid frequencies. Of course as this happened I shut everything down and rechecked and re-seated all my connections which changed nothing.
I've been super busy since completing this project but in the coming weeks will start to systematically deconstruct the setup to better understand the culprit(s). I am reasonably sure the pine shelving is at least part of it but am interested to see if the isolation technique I used is also damping the sound somehow? I phoned one of the rack companies that advertises a lot here on A'gon and a gentleman (forgot his name) was kind enough to answer some questions for me and mentioned that the coupling technique I used could be a major offender and that there are different schools of thought for when to isolate and when to couple directly. While I am going through this exercise I'll also experiment with moving my components (or most of them) from the front wall to an alternative place in the room. 
In the end I just wanted to share the experience with others that might be considering a similar effort and to say that there is much more to this than meets the eye. I didn't realize how much material, construction technique and perhaps even form factor (size and shape) can all make a dramatic difference. Since all of this transpired I've read a bunch of reviews on racks and many of them comment on the sound of the rack....I probably would have called BS on this before doing this project but now I am a true believer.
Bummer. I have been there. DIY oak table. Softened everything. Now it is spikes, maple, slate. Try putting granite under the components.
noromance, thanks for the feedback. Were you able to mod your original design by adding spikes, maple, slate or did you purchase a rack? Also, I considered granite but read some place that it can be tricky too.

Hi Chilehed

I design a lot of audio platforms and racks out of different types of pine and it can be one of the best sounding materials to use, but if done incorrectly can sound horrible.

It's too late to go back and reclaim the pine if you have already finished the surface, but there are some things you can back step that will help.

(1) get rid of the dampening

By now you know there is no such thing as isolating in the audio range. Your products are going to sound like your rack. Once you get rid of the dampening material, your going to hear some of the equipment range come back. You will also hear your room sound better.

(2) how is the wood finished

What type of finish have you used and how many coats, and how was the surface sanded? Pine takes a very long time to cure (especially that thick). If you live in a humid area you could set a dehumidifier in the room and set it at 30-35%.

If you would like you can get ahold of me from my website and I could walk you through some things.

Your probably a lot closer to good sound than you think, it's just that pine is such a wide range wood type it's easy to get lost in the voicing of it.

Michael Green

Hi Michael,
I can remove the damping material easily enough and will give that a try.
I got the pine slabs from a local mill and have seen no movement (expansion / contraction). The fellow I bought them from told me they were dry and it seems he was right. I live in the northeast so we get some pretty wild swings in humidity. The original boards were 2" thick and I had them surface planed and then I used a palm sander with 60, 120 and 220 grit sandpaper. I finished the boards with Minwax stain then Minwax Helmsman polyurethane (3 coats). 
Thanks for the feedback and advice.

Hi Chilehed

Yep after the dampening is gone you should give another report. And from there I'd be happy to help.

220 is going to close the pores so the poly isn't going to soak in as much but with pine you still might be ok (will just take longer to cure). A dehumidifier will help.

I do my pine in the desert so I start off super dry, and then cure it a long time before I start my sanding and coating. After I cure the wood it is about 1/3 the weight of when it was at the lumberyard.

But, that's not where you are at, so your going to need to be patient as the 3 coats is going to take a long time cure for you.

After the dampening is gone (be sure to sand and refinish where the dampening was) your still going to hear a cloudy sound. In time that will clean up. Your also going to want to look at what type of feet your going to want to use under your components.

What components are you using and I can make some recommendations for you when tuning in the transfer.

I had homes in Ohio and NY NY, so I'm pretty up on your curing area.

have a good weekend


Hi Michael- Nice to see you posting here on the forums!

Would brass cones help if used below electronic components to "decouple" ?

David Lynch

I did improve things by putting three granite sample blocks under the turntable and tube preamp. You don’t say what gear you are using so not sure how it will effect things. You can check out some of my pics in Systems.

Hi David, nice to see you. Hope all is well!

Brass is one of my favorite materials used sparingly, as you know. Systems can OD on brass pretty easy, that’s why I do a blend of materials under components. The MTD was designed to get rid of the upward shift caused by other cones and provide a better transfer. My MTD’s (mechanical transfer device) come in different shapes, designs and sizes to work with both old and modern component designs. I’m not saying cones have run their course, but the more detail folks are designing in their products the more squeezed the upper harmonics become causing clustering at certain ranges. Most cones amplify this. However there’s a new kid on the Block. The LTR Blocks are the latest greatest hit makers. The LTR Block is bringing music back into the game.

After moving to the desert in 2004, I found I could make an amazing tuning device that I was not privy to before. The voiced Low Tone Redwood Blocks changed my view of cones. Not just brass cones but any cone. Now I use one or two cones for flavoring when wanted but most of my system (systems) have become more in-tune. And a big plus is the voicing adjustability.

coupling vs decoupling

HEA sometimes steps on it’s own tongue and for years has been using the term "decoupling". After doing tests after tests by myself and many others I never found a case, in the audio range, where the components became decoupled from the surface below or above. In fact the opposite is true. When you set something on something else you are coupling not decoupling. Decoupling would be when you defeat gravity.

I don’t know if NASA still gives the tour but they use to have an anti-gravity chamber where you could go in and "decouple" yourself from the ground. This was done with air pressure pushing up. They also had other cool tricks using magnetic fields. But, in our hobby we don’t use those devices, and bladders, springs (including my Harmonic Spring), cones, rubber or any device subject to gravity and weight are in reality "coupling". Of course audiophile home brew experts will argue this, but it doesn’t change the fact that when you touch something with something else there is an interaction.

Anyway, I’m sure that’s more than you asked for, but you know how these threads are "say too little say too much" LOL.

again great to see you

Michael Green

I have always been intrigued by the whole coupling and decoupling thing and agree with your principle statements that no matter what you use, if items are still physically touching then they are coupled .... Period!

However would the exception to this be magnetic decoupled where they are basically touching nothing and in free float if you like?

I was looking at a tt that uses this type of decoupling and wondered if it truly might work as intended.
Obviously if the thing touching happens to be a spring, or air bladder or anything that acts like a spring, with mass on top of it it’s not considered coupling. It’s, you know....the other thing. Let’s not get too giddy here. If your component is super heavy, you’re in luck as my Super Stiff Springs can isolate objects weighing from 70 lb to hundreds of pounds.
I have built mag lev iso devices, I have also isolated mag lev Verdier turntable, which uses mag lev for isolating the platter only. Ditto air bearing Maplenoll turntable which uses air bearings for arm and platter. Both of those TG have extremely high mass platters. The difficulty with mag lev as an isolation method is keeping the objects physically totally separated since the opposing magnets slip sideways due to strong magnetic lateral forces. Usually stops are employed to prevent the entire top plate from slipping away. But you can certainly get pretty close to zero contact without too much effort.

Hi Uberwaltz & Geoff

That would be fun to try. I don’t know what audiophiles would call it, but a low mass floating amp would be pretty cool.


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My thoughts exactly on the magnets trying to slide away from each other and what you can use to stop that occurring.
Almost have to build a hexagon or octagon of magnets ( like a cage) so all sides are in opposing force constantly.

Sure it could be done, shoot nearly anything can be accomplished with enough time and money but would it be worth the effort?
While solid objects are often couplers, it’s a matter of at what frequency. Cones, spikes, and Sorbothane type rubber products provide isolation above a certain frequency---around 10Hz, it is said, not nearly low enough. Springs can provide isolation down to a lower frequency, as can air bladders. They act as a mechanical low-pass filter (behaving just like an electronic filter), attenuating vibrations above a corner frequency (and at a certain slope rate), and allowing them to pass through above that frequency (also at a certain rate). The lower the corner frequency the better, of course. The lower the frequency, the better the isolation. And the more expensive the price ;-) . Some make the claim that couplers (cones and spikes) allow vibrations to be drained out of whatever is placed on them, others dispute that claim. AS MG suggests, try it for your self---they are relatively cheap. I, like Geoff, suggest the DH Golden Sound Ceramic Cones. F brass---it's too soft.
@noromance and @michaelgreenaudio,
I am just a couple years back in the hobby after being away too long so setup is new and  simple. My main rig is Bluesound Vault2 source that I use to stream my CD library and also subscribe to Tidal hi-res. I use a Backert Rumba 1.2 pre to Pass X250.8. Loudspeakers are Aerial 7t. I also use a secondary Parasound A23 to drive a pair of Totem Dreamcatchers in my kitchen. I will try to post some pics in the next day or two. 
@noromance , thanks for the pics, cool setup!

F brass---it's too soft.

OK, your opinion - butt really?

For the few who insist brass is too soft a material for musical reproduction or for those who want to understand more on the topic of footers related to equipment racking these are the opinions of our company based on engineering, research and product development slowly evolving into a science.

Since brass is manmade there are quite a number of beta alloys available or you can manufacture your own formula. One has to determine the role in which brass or any other material for that matter is going to function as related to the equipment rack and design thereof.

Did you ever take a hard ceramic conical shape and apply it to steel shelving? That outcome could change your listening and opinion on material hardness immediately.

Since there are hundreds of steels manufactured each with a different chemistry and damping factor, what type of steel does one choose for shelving that manages the pitch variables of hard ceramics in order to outperform a specific brass alloy?

Hardness of materials has little to do with sonic outcomes especially when you take into consideration the rack design which is totally responsible for the cone or footer performance.

Racking functionality is based on a multitude of material choices beginning with the support legs and their chemistry make up. Add to that, the shelving materials and how the shelving is contacting the legs, how the rack mechanically grounds to the flooring where all racking systems mechanically ground to the greater mass either the flooring or the wall. The list of material selections, damping factors within the materials and variables in design methodologies are as vast as music itself.

What about the people who use wood blocks… where are all the wood cones? I only see a couple of wood cone designs so do the blocks have something more to do with performance?

There are more than thirty (our last count) companies selling brass versions of conical shapes and none of them come close to sounding alike. Lots of listeners do not know those sonic differences exist as brass always gets grouped into one generic understanding or becomes a single topic of conversation.

All brass cones sound incredibly different. After thirty years of manufacturing brass cones even we have changed the chemistry and damping factor of the brass currently used in our products as this was a key to our technology continuing to evolve all these years.

Is stone harder than brass? Whatever happened to all the stone cones that were made in the early days?

Important:  The cone or whatever shape or material used as footers are going to provide a level of sonic performance dependent on the shelf and material science and how the shelving relates to the rest of the racking materials and design technique. The rack itself determines overall function and sonic performance as the cone is only one part of the formula.

Some say stone shelving is much better than wood. If you take two cones designed using the same “geometry”, one made of brass and the other ceramic and place them on a piece of granite both cones will provide two entirely different sonic results. The results will vary even more if you use wood as the shelf medium since wood is in a constant state of flux due to temperature, humidity and aging.

Did I mention geometry? Any material shaped as cones, spheres, blocks, etc are entirely dependent on geometry for function. You can change the attack, sustain and decay sonic characteristics of any component chassis or speaker system by simply altering a shape no matter what material is being used as a foot.

Lastly, does the material matched to rack function produce a desired result?

‘My cone sounds better than yours’ disappeared from our vocabulary when the Sistrum geometry was invented twenty-two years ago. We wish racking would follow those same business progressions but people rarely if ever compare the sound and performance of equipment racking. The majority of listeners have no guarantee on how their rack functions or what it sounds like.

Does your rack actually serve as a functioning device or is it simply holding up the gear? Do you believe a rack is absolutely capable of holding back or excelling the performance of the equipment residing on it? Are you aware there are quite a few racking companies boasting isolation control, etc… but have little or no function in that regard?

Everything coming in contact with the rack’s shelving including the thousands of aftermarket and factory footers will yield various sonic results so again, material hardness is a non-factor in determining what sounds best until you know what shelving and rack design is being used prior to forming an opinion.

The equipment rack is the foundation of the audio system and governs the outcome of sonic entirety and therefore should be one of the key components considered for auditioning.

Every decision you make in choosing electronics, loudspeakers, wire, power distribution ET all over your lifetime is based on how your rack functions. If you indeed seek more from music and sound, do the labor and compare racking designs - more importantly compare the sound.

All this and we have not discussed the most important aspect of why our company chooses brass shapes and a specific steel for use and that is - Vibration Management!


Star Sound

Questions? Please feel free to telephone us.

Hi Robert you said

"All brass cones sound incredibly different. After thirty years of manufacturing brass cones even we have changed the chemistry and damping factor of the brass currently used in our products as this was a key to our technology continuing to evolve all these years."

I'm glad to hear you say this. The original Audiopoint was dated technology. I always wondered why you chose the original Audiopoint to distribute instead of designing your own.

Michael Green

Great post Robert. My outright dismissal of brass was intended to be subtly tongue-in-cheek, but it was too subtle! Your treatise above is far more deserving of consideration that is my flippant comment. Actually, I don't really "believe" in using cones in hopes of transferring energy (or vibrations), and certainly not for isolation. But each to his own!
When someone doesn’t believe isolation is possible (yes, I know it doesn’t sound right) I suppose the fallback position is cones of some sort, whatever he’s selling as it turns out, then try to justify it. There’re not even his cones, for crying out loud. But brass? I mean, come on! Brass is so far down the Moh scale of hardness as to be ludicrous. Of course he would say hardness is not important. Brass is all he’s got. What else can he do? For better results than relatively soft materials like brass or carbon fiber just go up a few notches of the Moh scale to tempered steel or cryod steel or NASA grade ceramics. It’s really the difference between pro audio or mid fi and the high end. I do not sell cones but when I did they were Golden Sound DH (Diamond Hardness) NASA grade ceramic cones, the best one of those being the Super DH Cone. Accept no substitutes!

Starsound said

"What about the people who use wood blocks… where are all the wood cones? I only see a couple of wood cone designs so do the blocks have something more to do with performance?"

Voicing accessories under components are just getting started. I bring in tons of different types of devices as well as obviously designing my own, and what I find is, as many different chassis that are out there so should there be tuning choices.

This will always be changing as the direction of components evolve.

Michael Green

By the way, I’m not entirely dismissing the original Michael Green brass cones - the really nice tall brass cones with a long ballistic tip, which are *very* good sounding. Alas, in the competitive world of high end audio there is always the risk of a faster gunslinger coming into town. But things got considerably more complicated in the past twenty-five years, you know, what with the advent of vibration isolation methodologies and new high-performance cone materials.

I don’t think there has ever been a comprehensive and scientific evaluation of competing audio cones but I think it would be interesting to see, including but not limited to Shun Mook, Mapleshade, Black Diamond Racing, Michael Green, Marigo, the original Tip Toes, Golden Sound, Starsound, Herbies, whatever. The Cable Company lists 4 pages of audio cones, a total of 40 different “cones.”

I do not have a dog in the big cone fight.

Geoff Kait
Machina Dynamica
Advanced Audio Concepts
Since there are hundreds of steels manufactured each with a different chemistry and damping factor, what type of steel does one choose for shelving that manages the pitch variables of hard ceramics in order to outperform a specific brass alloy?

Hardness of materials has little to do with sonic outcomes especially when you take into consideration the rack design which is totally responsible for the cone or footer performance.

>>>Well, it actually might be best to add some caveats to those statements. Racks are not necessarily the best solution for *vibration management* as you call it. No matter what is done to a given rack, even a very stiff steel rack, better results in terms of *sound quality* can usually be obtained by *eliminating* the rack entirely and moving the components to the floor and using vibration isolation devices. Racks by and large, even very RIGID ones, tend to transmit or even amplify seismic low frequency vibration. I would say the whole idea of a very rigid and well damped rack is rather archaic.
Maybe very true GK
But the reality unfortunately for the vast majority is that some type of rack is a necessary evil due to space constraints with amount of equipment owned.
I know I do not have room to spread all my gear out on the floor each on their own separate isolation platform or footers etc.

Perfect world scenarios do not exist for the majority.

If sufficient isolation is achieved for every component, the importance of the rack itself is minimized. Maybe not completely eliminated, but close enough for Rock ’n’ Roll---a classic musician’s joke. Audiophiles tend to drive themselves crazy, trying to achieve that last few percentage points of sonic improvement. And all in an effort to reproduce what is highly compromised sound to begin with. Does that sound anti-audiophile? High performance systems are often far better than the source material played on them. A system is only as good as it’s weakest link, and once a system has achieved a "certain" sound quality level, that is generally speaking the recording and/or storage medium. What level has to be reached for a system to be "good enough" is of course a very personal one.

MG’s basic premise raises the interesting question of how much of any given component's sound quality potential has been realized in the basic design and build of the piece, how much that potential can be more fully realized, and by what means. If can be argued that the less a component’s sound can be improved with tweaks, the better it has been designed and built. Is any tweak going to make up for a, say, power amp’s poor power supply? Would the money spent on expensive tweaks be better spent instead on a better amp? I’m just askin’.

I know, Uber, but surely you must realize I’m not into the whole vast majority opinion or necessary evils or convenience thing. And I have, I think, made that abundantly clear. Of course everyone is free to choose. Whatever.
Oh loud and clear GK, very loud and clear indeed!

I guess just stating the obvious there and that turns out to be well ….. obvious.

Does not mean I cannot play with different types of footing on my rack though, its on my todo list.....