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.
128x128chilehed

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!


Robert

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