Audio Rack Construction


Happy New Year All!

I'm planning a rack with three wood (maple) shelves using threaded rod as the supports. This will be something similar to Salamander racks. Besides, the metal washers and nuts, I'm going to be using some type of isolation washer that will contact the top and bottom of each shelf.
So...shelf, isoloation washer, metal washer, and then nut.

Questions: 1. When passing the threaded rod through each shelf, should the holes in the shelves not allow the threaded rod to touch, so the only thing touching the shelves are the isolation washers? 2. Besides neoprene, what's a good material for the isolation washers? 3. After leveling each shelf during assembly, I'm planning to add aluminum tubing over the threaded rod and nuts between each shelf for a cleaner look. This would mean that the top and bottom ends of the aluminum tubing would also contact the shelves. Should I avoid this, or additionally add some isolation material between the ends of the tubes and the shelves?
kennythekey

Showing 25 responses by kennythekey

I thought there would be no leaf unturned when it comes to this hobby. Good info. Thanks.
Thanks, John.

I already went at it with the Walnur Oil, and it looks nice. The instructions aren't clear, so I suppose I'll give it a few coats and plenty of time to dry. I found a penetrating oil stain in Cherry but it used urethane as a hardening agent and I don't want that.

I also found a spray-on clear laquer that's not made from plastic. Instead, it's nitrocellulose based (cotton). I'm considering using this on the brass to prevent oxidation because I prefer a bright brass look over a patina.
I like the the ideas about filling the tubing but there seems to be different thoughts about isolating the shelves from the threaded rod. Rigid is very important but most of the better rack manufacturers use some sort of isolation between the shelf and the frame.

I am planning to drill and tap the bottom of the rods and screw in heavy brass spiked feet.
Well, there you have it nice and simple.

I know that brass is a coveted material, but it appears that Slipknot is using steel but that's hard to see. Brass gets expensive especially with all those nuts and bolts. I was thinking about using 5/8" steel rod and fasteners, and then covering it with the aluminum. I was first thinking 3/4" but nuts at that size are special order where I am.

For the top shelf I was going to use brass nuts/washers to match the bottom feet. I've been looking for a flat brass end cap for the top nuts but no luck.
Thanks guys for the source information and excellent advice. Does anyone have an idea on how to finish off the ends of the rods for the top shelf? I've seen round nuts and end caps on manufactured racks but am having problems locating.
BR3098 - Thanks, I'm just copying the threaded rod concept from Salemander and will be using heavier maple shelves and as recommended, shot inside the external tubing around the rod. The end result should be a lot heavier and more rigid. I'm not placing my turntabl;e on this rack.

Jdoris - Thanks for the link I will check it out.
Wow, tons of info from the link provided by Jdoris. The original thread was back in 2006, and the raw materials have gone up nicely since then. That still won't stop me.

Lots of stuff to go through and I'm taking off for vacation. Will be back next week and will re-focus then.

Thanks everyone!
I'm back from vacation and had time to contemplate all of your good information.

I've decided to abandon my wall mount ideas for my Table, and place it on the new rack. My Target wall shelf was a failure, so why shell out big bucks for a Finite wall shelf? The Finite was maple with an aluminum anodized back plate, so I was going to add silver aluminum anodized tubing to the new rack. I don't need to do that now.

I have an old Farmhouse, so I would like to hide the industrial look of the rods and nuts. Looks like I will be using an anodized tubing with a colored powder coat instead. I found a local source for this and if their product is decent I will let everyone know becuase it's so inexpensive.

I will also add shot to the tubing but in the end I'm hoping that this eliminates any potential ringing and does not make the sound less lively. Any thoughts on that?
Thanks John,

I've already purchased the maple shelves and hardware thanks to the help from everyone.

The 24" X 18" 1.75+" shelves were $69 each and ony $1 to ship all due to holiday pricing from Overstock.com. I am very pleased with the fit and finish. The 3/4"-10 rods and hardware I got from McMaster. Everything is brass.

I remember when reading your thread from 2006 that you were getting used to the look of the nuts and rods. If I wind up using the tubes I will post a picture. Maybe, you and others will want to use/add them since they come in Slver Satin Aluminum, Black, Dark Green, and Rust Brown. The cost is very low so I don't want to release the source until I first check one out.

We're all concerned about sound, that's why I'm trying to find out if I'm sacrificing some by using the tubes, or if I'll be okay if I prepare the tubes properly.
Finish question. Regarding maple shelves, does it make any difference for finish...oil, laquer, stain, etc.? For preservation and sound? I just plan to use a mineral oil.
Thanks George.

Yes, I've got everything but the tubes and they'll be here soon. I'm going to have a machinest cut them because they need to be precise and I don't have a band saw or lathe.
Everything is brass and maple but the tubes are anodized aluminum with a powder coat. I'm going to fill them as advised with lead shot for mass and no ringing. I bought the acorn nuts for the top, so I'll see how they do for now.

I have a Mapleshade platform with IsoBlocks for my table, so I'll use that on top and take it from there. I'm using the HeavyFeet with a 3/4"-10 tap for the supports. I won't use the feet for leveling but will level the shelves instead, so the feet will get maximum thread. I'll only be using two of the four shelves right away. I was going to get a headphone amp but the rack has delayed that purchase.

I'm really enjoying this and get to make it look the way I want while still saving money. From the good and consistent advice from everyone out there, I'm pretty sure it will sound real good as well. You can't ask for more than that!
Thanks John, from the paper that Theaudiotweak provided the link to, it appears that you should steer clear of plastic based solutions.
I'm ready to drill my shelf holes but have a question. What's a good way to support the heavy maple shelf on the drill press for the corner holes? Right now, my drill press is only set up with the standard (small) metal work base.
Thanks for the info Magfan.

I'm am debating over the tubes at least for now. I will be expanding my rack pretty soon and I would not want to disassemble/re-assemble. I'm also adding new components and don't know the height yet. This means that the tubes would be a pain right now and I would have to cut new ones if there are any height changes.

By the way, the tubes I received are really nice and inexpensive. We're talking 0.22 and 0.28 cents per inch. For those that are interested here's the link http://www.landmarkflyrodtubes.com/Tubes/aluminum.htm
Thanks guys.

I got it done and it's perfect...whew!!!

I mean perfect in my mind, you know?

I got lucky. Home Depot had pre-cut acrylic exactly the size of my shelves (24 X 18"). I made a template to fit over the shelves and marked/drilled small holes from the corners. Then drilled the 13/16" holes with my drill press. I simply attached a board to the base of the drill press that supported the shelves just fine. Later, I stacked my shelves and all of the holes lined up perfect. A little anxiety can go a long way!

Anyway, I just got my Walnut Oil, but still have to wait on the feet. I'm having a local machine shop drill and tap my Mapleshade Heavy Feet to 3/4"-10. Still waiting, so more news later.
Hi All!

Jdoris had suggested using Walnut Oil and I like the idea and have it. I also checked out some of your rack pictures and saw that many of you have a redish tint to your wood.

Have you accomplished this using Maple, or are you using Cherry instead? I'm asking because my shelves are Maple and the Walnut Oil looks like it will leave a greenish tint.
Thanks, I just rubbed the oil in with a cloth. I'm in Colorado where it's pretty dry, so I better look into the steel wool.

The worst part of this project, is cleaning the brass rods that I got from McMasters. I spent about twenty five minutes last night on one rod and I'm still not quite done. I did the two-stage dishwasher soap/Brasso cleaning that produced many blackened rags. Makes me want to seal the rods instead of letting them oxidize again. For me, it's always most difficult to finish those final details, but I am looking forward to the assembly.

The only negative I see with the nitrocellulose based laquer is that it's highly flamable as it's a relative of dynamite. Windows open, turn off the electric heat...and it's winter!
Finally finished the FlexiRack!

I'm very happy with the way this project turned out. Thanks everyone for your help and suggestions.

Here's a picture...no surprise that it looks like others in the forum. http://cgim.audiogon.com/i/vs/i/f/1265411095.jpg
Thanks, I do have one issue but it's not the rack.

The rack is rock solid when the shelves are perfectly leveled. You almost don't need a level because as you adjust the nuts, as soon as the next shelf finds level...you can feel the rack lock-in like it's cemented in place. I love it.

The problem is when I put my Mapleshade turntable platform on top. The platform is not level but the top shelf is. Either the platform isn't true or the Isoblock feet aren't exactly the same height...hmmm. If I adjust the top shelf to compensate for the platform then my rack is not quite as solid as it was. I don't want to adjust the feet on my turnatable because it sounds best with the feet screwed in all the way in. Any ideas?
Markeetaux...you should do that! I didn't stain my shelves because I like the natural maple and I'm considering new speakers. If you look at my pic you'll see that the cabinet to the right is yet another finish! Well, I'm replacing that cabinet as well. Maybe in the end it will all be maple.
Thanks John.

Okay, so I started listening and I was mesmerized. Not that everyone would have such an experience, but I realized just how poorly I treated the support of my components in the past.

Every audio attribute was bettered. It sounded like I did a full system upgrade and it costed what, $700? I will never underestimate the rack as a true component again.

Oh, and I eliminated my foot-fall problem. Did I ever really have a foot-fall problem or was it just the crappy rack I used in the past? The energy that this flexi-rack directs outward is awesome. I lightly pound on a shelf and I can hear my table in the middle of my room rattle. I jump up and down next to the rack, and the glass of water on top...nothing. Now, I can identify and fix room vibration problems using my rack...hah...hah...okay, I'm getting silly.

Yea, I'm happy. My rack is fully tightened but I may experiment with the nuts to see what's up with that.

Goodbye Target, goodbye old side table, goodbye Billy Baggs.
Theaudiotweak -

I have no experience with the Sistrum.

I did find out that my maple platform is not warped, but the Isoblock feet are different heights because they compress differently based on the component's weight distribution. This would then make it difficult to level a component without leveling feet or a flexiRack.

As you suggest, this should not be an issue with a rigid metal platform.
To be fair to Mapleshade, I spoke to Pierre and this is normal. He suggests using 2" X 2" manila paper squares under the blocks as a shim and twisting each block until the resistance is the same for all.