DIY Rack - 3 Legs or 4?

MCM_Fan

MCM_Fan

AK Subscriber
Greetings Fellow DIYers,

I am in the process of designing a DIY audio rack and matching speaker stands. I plan to use the 8020 aluminum extrusions for the uprights and butcher block maple for the shelves. Pretty standard stuff so far. I've seen many other beautiful racks made using these materials. But, I plan to make mine a little different.

Instead of using the preferred 1515 (1.5" x 1.5") extrusions with one per corner, I plan on using the 1530 (1.5" x 3") extrusions. The plan is to place one upright on each side of the selves about 3" (maybe a little more) back from the front. Then either a 3rd upright centered along the back of the shelves, or two uprights along the back of the shelves about 3" in from the sides. I hope that was clear. I wish I could provide a photo, but I've never seen a similar design.

This rack is for a bedroom system, and will be holding (at most) a Sansui AU-717, Magnum Dynalab FT-101A and Marantz DV6600. The Sansui is the only heavy piece. So, the bottom shelf will be reinforced to support its weight.

I want something that's open to allow plenty of air circulation and also to show off this beautiful equipment. I may occasionally rotate in other gear (an NAD 3150 integrated amp or Sansui TU-919 tuner and maybe a newer SACD player). I may evetually add a DAC and Airport Express for steaming digital files, but the basic system will always be an integrated amp, FM tuner and SACD player.

So, what do you think, 3 legs or 4? I know from my experience as a large format photographer, it's a LOT easier to level something with 3 legs (tripod) than 4. But, it's not like I'll be moving it around a re-leveling it often. So, what do you think?
 
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I like the stability of 4 legs personally so that's the design I would go with.

Just my .02
 
Don't know how heavy that gear is but it seems to me that the CG of an equipment rack can get kind of high without you realizing it. I would use 4 to keep the CG inside the floor plan of the legs.

Shelly_D
 
I would go with 4 as well, only because having one leg in the middle rear tends to place it in the way of plugs on the back of equipment. I know this because I went with 3 legs :(
 
Well, so far it seems like 4 legs is the preferred solution.

Concerning the center of gravity, it will be quite low and the rack will be overbuilt for vibration isolation. There will be a single, small Definitive ProSub 800 subwoofer mounted on a separate platform below the rack The first shelf, which will hold the heaviest component, by far, the integrated amp will be about 16" off the floor. Right now, the Sansui AU-717 (about 39 pounds) is out for service. So, an NAD 3150 (about 23 pounds) is filling in until the Sansui is back in service.

There will be only 3 shelves, and the other two components are very light. The Magnum Dynalab tuner tips the scales at 12 pounds and the Marantz DV6600 is a featherweight 5.5 pounds.

The total heights of the rack will only be 36" with the lighter components up high. The bottom shelf will be reinforced to support the weight of the Sansui, and lots of spikes, Vibrapods and sand used to dampen vibrations. The uprights of both the audio rack and the speaker stands will also be filled with sand.

This rack will be heavy and about 75% of the weight will be below the center line. So, I'm not worried about it tipping over, regardless of the number of legs.

Concerning the cabling, since I want to mount the rear leg(s) on the back of the shelves, 4 legs would cause more blockage than 3.
 
Yes that 4 leg is required for stability. Eventually I have to convert my DIY tnt flexi rack from 3 leg to 4 because of wobble in 3 legs.
 
Each has it's own merits. The real question is how much is the floor off level? And axiomatically- where are the transformers located in the gear? if floor is not level, say an old house, and the transformers end up in the same rear corner, it could be unstable.

In the manner described, 3 legs can work and has some visual interest to it. Now if you were to go with slabs of granite for shelves, that would be impressive, weighted well and be reasonably well damped.

The thing with 3 legs- it will always have the feet on the floor- unlike 4 legs- if the floor is uneven, invariably you end up shimming under one leg whenever you move it to new spot- even a half inch over.
 
Good question on the transformers. Both amps are dual transformer designs with the transformers on the left side. The heavier Sansui doesn't feel terribly unbalanced, maybe something like 60/40 weight distribution. The lighter NAD is definitely more unbalanced, seems more like a 75/25 or even 80/20 weight distribution.

I plan to use wood (and maybe some sand) for the shelves. While granite has much more mass, it doesn't dampen vibrations nearly as well as wood. Besides, I already have all the wood for the shelves and speaker stands, with a lot left over. I bought an old, rather large maple butcher block table at the local Goodwill outlet for $15. The finish is in horrible condition, but I plan to sand it down and refinish it anyway.

I haven't checked the floor to see how level it is, but it's a newer house, built in 2008. So, I suspect the floor is reasonably level. I will have adjustable spikes on each of the legs. So, the rack can be leveled by adjusting the spikes.
 
I'd definitely go with 4 legs.

Sure, 3 legs might be OK under ideal circumstances. However, you should consider what might happen if someone or something (such as a dog, etc) inadvertently bumps up against it.

Just something to think about...
 
Wow, no love for 3 legged racks. I like the look and am not at all worried about the rack getting knocked over. It will be a VERY heavy rack, with a low center of gravity, close to a wall in a low traffic area. No small kids or dogs running around. Regardless of the number of legs, this thing will be severely overbuilt - to dampen vibrations, but all that extra mass has the added benefit of making it very stable. The legs I'm using are twice as wide as the typical 1.5" x 1.5" legs and will be filled with sand. The bottom shelf, for the amp, will sit in a sand filled tray, similar to the top shelf on this Adona rack:

http://www.adonacorporation.com/zerogsb.html.

I suspect it will be so heavy that I'll have to disassemble it if I ever want to move it more than a few inches.

Last night, I was convinced to go with 4 legs, but have been playing around with some 3 leg concepts this morning. I'll probably make my final decision today or tomorrow and order the parts on Saturday.
 
MCM_Fan said:
Wow, no love for 3 legged racks. I like the look and am not at all worried about the rack getting knocked over. It will be a VERY heavy rack, with a low center of gravity, close to a wall in a low traffic area. No small kids or dogs running around. Regardless of the number of legs, this thing will be severely overbuilt - to dampen vibrations, but all that extra mass has the added benefit of making it very stable. The legs I'm using are twice as wide as the typical 1.5" x 1.5" legs and will be filled with sand. The bottom shelf, for the amp, will sit in a sand filled tray, similar to the top shelf on this Adona rack:

http://www.adonacorporation.com/zerogsb.html.

I suspect it will be so heavy that I'll have to disassemble it if I ever want to move it more than a few inches.

Last night, I was convinced to go with 4 legs, but have been playing around with some 3 leg concepts this morning. I'll probably make my final decision today or tomorrow and order the parts on Saturday.
Click to expand...

I built mine with 3 legs. No problems with stability at all, even loaded down.
 
I'm out of town at this moment and won't be back until next week. I'll post some even if you already have made up your mind when I get back.
 
Four, just for the stability. What may seem adequate from a strength standpoint may be an issue when it comes to vibration ...

Speaking of which ... I'd be more concerned about the sub below the rack. Not sure whether wave propogation would make that the best or worse location in your system. Every room is different. Give it a try, and you can always figure out how to isolate your equipment later, but I'm thinking sorbothane may turn out to be your best friend down the road. Just be careful how you use it if you do ... stuff can leach over time and stain the wood. I'd also consider spiking the sub to minimize floor coupling.
 
This 3 leg flex stand is stable. I built another one with the 2 legs on one side. Just as stable and no interference with wires.
 

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MCM_Fan said:
Wow, no love for 3 legged racks. I like the look and am not at all worried about the rack getting knocked over. It will be a VERY heavy rack, with a low center of gravity, close to a wall in a low traffic area. No small kids or dogs running around. Regardless of the number of legs, this thing will be severely overbuilt - to dampen vibrations, but all that extra mass has the added benefit of making it very stable. The legs I'm using are twice as wide as the typical 1.5" x 1.5" legs and will be filled with sand. The bottom shelf, for the amp, will sit in a sand filled tray, similar to the top shelf on this Adona rack:

http://www.adonacorporation.com/zerogsb.html.

I suspect it will be so heavy that I'll have to disassemble it if I ever want to move it more than a few inches.

Last night, I was convinced to go with 4 legs, but have been playing around with some 3 leg concepts this morning. I'll probably make my final decision today or tomorrow and order the parts on Saturday.
Click to expand...

Three legs on all of my gear; turntables (x2 at 200lbs each), and rack. The only four leg that I have is for one pair of speakers, and, they are a PITA to get level. Three legs is extremely stable and far easier to level.
 
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