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THR33P4C
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Trashing the Cabinet Idea... Building an Open Rack

Ok, now that I have done my research my mind has been completely changed. The new plan is to build an open rack out of wood with MDF Shelves which will rest on points or some other isolation product.

This is what I will be modeling my design off of:
http://www.soundstage.com/revequip/silentrunning_craz_4.htm

I have a couple questions that need answering before I put together a design:

1. I have a matching NAD preamp and Tuner, they look really nice together. I am considering putting them on the same shelf to save on materials and rack height. (Tuner stacked on top of preamp) Since the Tuner will never be on when other sources are running it should act as a weight for the preamp right? And even when the Tuner is on are there any moving components? So the big question is- can I set these two components on the same shelf?

2. This is a DIY rack and I am trying to save as much money as possible. The key to this rack will be what I use for isolation on the shelves. Cones and Spikes are very expensive and they are not really practical for this design. I was considering using field points (archery) they would work the same way as spikes. Are there any other materials that I could use such as isolation pads or some cheap tweak to isolate the shelves?

Jan, thanks for encouraging me to do thorough research before starting this project. I think I have a better grasp on the concepts and think this type of rack will be much more effective than the original cabinet idea.

Jan Vigne
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Re: Trashing the Cabinet Idea... Building an Open Rack


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Since the Tuner will never be on when other sources are running it should act as a weight for the preamp right?

You see this as good or bad?


Quote:
Are there any other materials that I could use such as isolation pads or some cheap tweak to isolate the shelves?

Go the the sporting goods store and buy a bag of raquetballs. Cut them in half. How were you going to get the archery points to stand upright?

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Re: Trashing the Cabinet Idea... Building an Open Rack


Quote:

Quote:
Since the Tuner will never be on when other sources are running it should act as a weight for the preamp right?

You see this as good or bad?

Good, there are products that you can buy as weights for the top of your components no? Mrlowry mentioned using them.


Quote:
How were you going to get the archery points to stand upright?

-Field points have threading on the back. I would have to set threaded inserts into the bottom supports and screw the points in facing up. The problem with this plan is that the points are pretty long and this would mean thicker shelves.

-How much do the balls compress? When there is weight on them do they go almost flat? I don't want much space between the MDF shelves and the frame...

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Re: Trashing the Cabinet Idea... Building an Open Rack

I think if you keep searching you will find low profile spikes/cones and floor savers for under $20 per shelf. Another option is to forgo the cones for isolation and go with rubber or sorbothane.

http://store.acousticsounds.com/category.cfm?section=equipment&id=61

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Re: Trashing the Cabinet Idea... Building an Open Rack

The Sorbathane looks like a really nice alternative. It would also work better with the rack design I am going with. However, It is hard to find sheets for sale that are thick enough. Ive been using the Calculator from Sorbathanse's site and it looks like anything under 1/4 inch actually harms the isolation. I could stack sheets I guess though. It also looks like you get the best results by customizing the size and thickness of Sorbathane used on each component which is nice.

Here are some links to products I have found:
http://scientificsonline.com/product.asp?cs=p&pn=3037000&bhcd2=1137183320

http://shop.ebay.com/merchant/dang-good-stuff_W0QQ_nkwZQQ_armrsZ1QQ_fromZQQ_mdoZ

http://store.acousticsounds.com/browse_detail.cfm?Title_ID=42793

I don't think that last one is Sorbathane but it might work in a similar way.

I think the Ebay store selling the feet might work well, but they are so small at 3/4 inch diameter. They are also not as customizable as a sheet would be.

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Re: Trashing the Cabinet Idea... Building an Open Rack

You could use 3 spikes per shelf in a triangle configuration thereby cutting the # necessary.

My SolidSteel rack is this way and is very stable. 2 spikes in front, 1 in the back center.

Some people say this provides more isolation by having only 3 contact points.

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Re: Trashing the Cabinet Idea... Building an Open Rack


Quote:
Good, there are products that you can buy as weights for the top of your components no? Mrlowry mentioned using them.

First, do not automatically assume that what works for one system works for all systems. Each component is different and responds to different tweaks.

Second, the idea of mass loading a component is typically done with a mass that extends over the entire or most of the top plate, not just resting on four points of contact.

Do more thinking here.


Quote:
How much do the balls compress? When there is weight on them do they go almost flat? I don't want much space between the MDF shelves and the frame...

You build to suit your desires. If you don't want much space but want a particular device under the shelf, you build to suit that device. However, without listening beforehand, do not assume the tweak that worked on the other guy's system will automatically work on yours. Make this a rule most especially when you are moving from isolation by mechanical diode type devices like spikes to resonance absorption devices like racquetballs or Sorbothane.

Part of DIY is providing the ability to experiement to find what suits your system - now and in the future - and what suits you.

No, the raquetballs do not squish.

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Re: Trashing the Cabinet Idea... Building an Open Rack
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Re: Trashing the Cabinet Idea... Building an Open Rack


Quote:
I think if you keep searching you will find low profile spikes/cones and floor savers for under $20 per shelf. Another option is to forgo the cones for isolation and go with rubber or sorbothane.

Check these out:
http://cgi.ebay.com/Small-Audio-Isolatio...93%3A1|294%3A50

These would cost less than $10.00 a shelf, even less if I only use 3 per shelf... This would be easier than sorbothane I think. Plus they come with threaded inserts which would make them a breeze to install in the rack.

If I go with these should I install them with the points facing up to make contact with the shelves or connect them to the shelves and have the points rest on the rack?

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Re: Trashing the Cabinet Idea... Building an Open Rack

In most applications spikes are used point side DOWN as they are meant to channel vibrations AWAY from the component. So the flat side of the cone would come into contact with the bottom of the shelf and the point would come into contact with the rack.

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Re: Trashing the Cabinet Idea... Building an Open Rack

Ok, does it need to be metal on metal contact or can I just set the spiked shelves on top of the rack's supports? Maybe drill holes in the rack for the spikes to set in?

Looking over the plans for the FlexY Table they suggest damping paint. What is this? Where can I get it?

-Also, does anyone know if laminating my MDF shelves will harm the sound?

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Re: Trashing the Cabinet Idea... Building an Open Rack

The spike can contact the rack directly.

The kind of paint that they are talking about is something similar to this:

http://www.dynamat.com/products_car_audio_dynaspray.html

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Re: Trashing the Cabinet Idea... Building an Open Rack

Laminating MDF? I'm not sure what you mean by "laminating'. There is no grain to MDF so you cannot oppose the grain in alternating layers. Are you talking about coating the shelf with a plastic?

All materials sound different under your equipment. MDF is cheap and dimensionally stable so it works well for shelves while providing a fair amount of damping. Some people feel MDF overdamps the sound of the system. Try thinner MDF for a different sound. Or two layers of MDF with a damping compound between the layers. Try plywood, glass or bamboo and you'll have a different sound coming from your system.

Read up on "constrained layer damping".

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Re: Trashing the Cabinet Idea... Building an Open Rack

I'm talking about making a shelf like a laminate counter top
http://www.regencyedge.com/images/2040952b.jpg

What you do is apply a thin layer of sticky glue to the MDF and to whatever laminate you want to use. After that you stick the MDF and laminate together and rub stiff pieces of plastic across the surface to really bind the two materials together. Its basically adding a thin layer of synthetic to the outside of the MDF.

My Dad and I put together my whole work desk this way:

It can create a really nice finish, much more attractive than paint on MDF imo. I am planning on making the shelves this way unless there is some really bad acoustic response caused by this process. I will anchor the threaded inserts through the laminate and into the bottom of the MDF and then screw in the feet I referenced earlier with the points facing down.

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Re: Trashing the Cabinet Idea... Building an Open Rack


Quote:

Quote:
Good, there are products that you can buy as weights for the top of your components no? Mrlowry mentioned using them.

First, do not automatically assume that what works for one system works for all systems. Each component is different and responds to different tweaks.

Second, the idea of mass loading a component is typically done with a mass that extends over the entire or most of the top plate, not just resting on four points of contact.

First, I am not assuming anything except that there are products that are used as weights on the tops of components. I was just asking if there was a downside to stacking the components.

Second, I can just take the feet off of the tuner the components have the exact same dimensions. That would be complete metal on metal contact over the entire surface area. However, even though the concept makes sense I doubt that it will improve the sound.

*Bottom Line* can I put these two components on the same shelf?

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Re: Trashing the Cabinet Idea... Building an Open Rack

One of the negatives of stacking components is that their power supplies are really close and the radiated noise from one power supply could have a negative affect on the other component's sound. Even when off most electronics are still drawing current and part of their circuit is always on. Preamps deal with some of the smallest and most delicate signals, particularly those with phono stages so safe guarding the preamp is of paramount importance to creating a system with as low a noise floor as possible. The other negative is that of vibration again. Some times stacking components becomes necessary but try to avoid stacking anything on top of or below preamps because of the small signals that are inside or power amps because of their relatively large power supplies and the amount of noise they can radiate. If you have to stack two things I'd probably look at stacking the CD player and tuner, when listening to one turn the other one off. That won't completely eliminate the drawbacks of stacking but will minimize them. I'd try the CD player below the tuner first because of how many vibrations the spinning motor generates.

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Re: Trashing the Cabinet Idea... Building an Open Rack


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Second, I can just take the feet off of the tuner the components have the exact same dimensions. That would be complete metal on metal contact over the entire surface area. However, even though the concept makes sense I doubt that it will improve the sound.

It would also cut off air flow through the amplifier. Best not to stack if it's avoidable.

You can buy veneered and laminated MDF. Be certain it is MDF and not a pressed board core. As long as there are no voids in the layering a thin laminate shouldn't affect the sound overly much.

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Re: Trashing the Cabinet Idea... Building an Open Rack

Ok, I think I will laminate my own MDF shelves. I would like to avoid stacking but there may be no way around that... What if I stacked my tuner on top of my tape deck?

-Should I use similar (spiked feet) Isolation for my power conditioner?

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Re: Trashing the Cabinet Idea... Building an Open Rack

I just thought of something... I don't need spikes on every shelf. duh... Spikes will benefit the turntable and CD player the most right? I can spike those shelves. I should probably also spike the preamp shelf and the amp shelf because those are core components that are also very sensitive.

For the Tape Deck, Tuner, and Power conditioner I can experiment with other DIY tweaks like wood blocks and soft materials.

Isn't this what you guys have been telling me all along?

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Re: Trashing the Cabinet Idea... Building an Open Rack

Ya, you could stack the tuner on the tape deck, or vice versa. That would be better than my suggestion putting it on top of the CD player. I forgot that there was a Tape deck in the equation.

You can certainly spike some of the shelves and try other stuff under the other shelves. At worst you could always go back and spike the remaining shelves later.

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Re: Trashing the Cabinet Idea... Building an Open Rack


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Isn't this what you guys have been telling me all along?

I've been telling you to think and reason before you cut any material. I've suggested you look first at what has come before in aftermarket and DIY racks and isolation devices and methods to benefit from the knowledge and experience of others.

Have you been doing that?

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Re: Trashing the Cabinet Idea... Building an Open Rack


Quote:

I've been telling you to think and reason before you cut any material. I've suggested you look first at what has come before in aftermarket and DIY racks and isolation devices and methods to benefit from the knowledge and experience of others.

Have you been doing that?

It looks to me as if he has. Not only in this thread but in the others it seems like he is asking all of the right questions and also comes back with information from other sources to ask about it. He seems quite willing to change directions when the information he finds isn't in line with what he originally wanted to do.

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Re: Trashing the Cabinet Idea... Building an Open Rack

Yes, for the most part I would say he has. I'm curious to see if he thinks he has. There's a lot of information of gather and digest in just a few days, and a lot of it will lead you in different directions - such as constrained layer damping. I don't think this is a weekend read and then pull out the saws type of project.

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Re: Trashing the Cabinet Idea... Building an Open Rack


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Yes, for the most part I would say he has. I'm curious to see if he thinks he has. There's a lot of information of gather and digest in just a few days, and a lot of it will lead you in different directions - such as constrained layer damping. I don't think this is a weekend read and then pull out the saws type of project.

Ok, first... thanks Mrlowry for coming to my defense. Lets get a few things straight Jan... You need to know first of all that I am a college student ( money is tight ). I have been on break until today and I have spent much of my break doing research on audio gear. I don't know if you read the component list I put up in my cabinet post but if you did you would realize that I am putting together a budget system. I have vintage NAD seperates and a mismatch of used and new sources. ( maybe you skipped that section to get straight to ripping a noob apart) I took all of your posts seriously and referenced almost all of the topics that you suggested. Even after thanking you for your help you continue to insult my intelligence.

I admit I didn't take the time to research constrained layer damping... by the time you posted that suggestion I had already decided on laminated MDF for shelves. And frankly I don't care about constrained layer damping. (I don't have the time or money to put together custom damping shelves that may or may not benefit my entry level system)

And as far as pulling out the saws go... My father will be helping me put together this rack. We won't be building it in some stuffy garage with a skill saw and horses either. My dad is an experienced contractor. We have an entire wood shop with everything... Top of the line table saw, Planers, Sanders, Routers, you name it. We also have access to top quality lumber and supplies.

I really do appreciate your advice and suggestions Jan but it seems like every time I decide on something along the lines of what you recommend you bring up something supposedly much better that I should do instead.

This section of the forum is supposed to be a supportive question asking and information source for new people getting into this hobby. For the most part my questions (some of which must have seemed really stupid) Have been gladly answered. Mrlowry and many others have been very helpful and supportive... I'm not saying I don't value your advice Jan but intimidation and criticism are not very successful mentoring tools...

Jan Vigne
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Re: Trashing the Cabinet Idea... Building an Open Rack

Why did you take my post as intimidation and criticism?

The level of your present system makes no difference to building the best product you can afford. Do you plan on this being the last system you ever own? If so, you want to get the best out of it. If not, then plan for the future.

If you've been taking my advice, you will have discovered many of the goals of a good rack are contradictory. If you want isolation, you have to sacrifice rigidity. If you want rigidity, you normally need some degree of mass; mass leads to higher degrees of lower frequency resonances and this is especially true when you are working with more traditional materials. Resonances are what you are trying to minimize. Knowing just one or two of those things will cause you to believe you've solved the puzzle when in reality you've actually complicated the maze.

I've been telling you to think this through and reason before you act. There's quite a bit of information out there to be found and taken in. There are good sources for the information you require to do the job correctly, not the least of which will be found in some woodworking books - if you stick with traditional materials.

Just being fed information only serves one purpose.

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Re: Trashing the Cabinet Idea... Building an Open Rack

You make a good point about building a rack to last through the years. I think the design I have come up with will be pretty flexible as far as isolation and dampening goes. However the shelves will be fixed so I have to make sure I allow some room for future upgrades.

Because I am using traditional materials I will probably do best with the concepts of rigidity and mass loading. I plan to use maple for the rack itself (The 4 supporting beams, and each shelf frame) I also plan on installing long spikes in the bottom of each supporting beam to make contact with the floor. The shelves will be made out of MDF at least 1 inch thick with laminate on all sides. Each shelf will be customizable as far as the contact surface goes. As mentioned before i will probably spike the CD player, Amp, Preamp, and Turntable shelves to maximize their mass while reducing the points of contact with the rack. For the other components I will experiment with other forms of contact. If I find that what I do for a certain shelf doesn't work I will reconsider the method of contact with the rack.

Is this an acceptable design?
-I will post drawings and a material list later tonight.

-Also, I still haven't decided on 3 or 4 spikes per shelf, is there a noticeable difference between the two or are 3 per shelf suggested only for leveling purposes?

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Re: Trashing the Cabinet Idea... Building an Open Rack

The design sounds good to me and Maple should be a good choice of woods. MOST components are a little over 17" wide some of the bigger rack mount stuff can be up to 19" wide. So I'd recommend a shelf width of 20 to 21" so that the rack doesn't limit your component choices in the future. Depth is a little trickier because some amps are super deep but if you did 20 to 24" you'd be able to fit just about anything. If it wasn't that deep you'd still probably be able to cheat by letting the amp hang out the back anyway or build a separate amp stand if you ever get on of those huge amps.

Three spikes are used often times because three points are all that are necessary to define a plane. Also three points offer less contact, and thus area for vibrations to enter a component.

With respect to placing the spikes under components I usually try to make sure that one spike is under the power supply because they do create small vibrations. With CD players try to make sure that one spike is directly under the CD tray to help drain as much of those vibrations away as possible.

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Re: Trashing the Cabinet Idea... Building an Open Rack


Quote:
If you want rigidity, you normally need some degree of mass; mass leads to higher degrees of lower frequency resonances and this is especially true when you are working with more traditional materials.


Quote:
The shelves will be made out of MDF at least 1 inch thick with laminate on all sides.

Mass loading typically means exceptional amounts of mass spread across large surfaces or large amounts of mass situated on a very small contact point. There are components that react poorly to mass.

Otherwise, keep thinking until you're ready to build.

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Re: Trashing the Cabinet Idea... Building an Open Rack


Quote:
The design sounds good to me and Maple should be a good choice of woods. MOST components are a little over 17" wide some of the bigger rack mount stuff can be up to 19" wide. So I'd recommend a shelf width of 20 to 21" so that the rack doesn't limit your component choices in the future. Depth is a little trickier because some amps are super deep but if you did 20 to 24" you'd be able to fit just about anything. If it wasn't that deep you'd still probably be able to cheat by letting the amp hang out the back anyway or build a separate amp stand if you ever get on of those huge amps.

-my biggest component is my CD player at 17.3" wide and a depth of 16.8" Ill probably end up with 20x20 or 20x18 shelves.


Quote:

With respect to placing the spikes under components I usually try to make sure that one spike is under the power supply because they do create small vibrations. With CD players try to make sure that one spike is directly under the CD tray to help drain as much of those vibrations away as possible.

I won't be directly spiking components, at least not yet... The idea is to spike the bottoms of the shelves, so putting a spike under the CD drive will probably not be possible.

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Re: Trashing the Cabinet Idea... Building an Open Rack

Here are some drawings and descriptions of my tentative design... If anyone notices any big flaws or would like to offer any alternative ideas let me know.

I will be following the above drawing pretty closely although I will be flipping the middle two shelves around to get the preamp higher off the ground for ease of adjustment.

-From top to bottom on each shelf
1.Turntable
2.CD Player
3.Preamp
4.Tuner
(and)-Tape Deck
5.Amplifier
6.Power Conditioner

The Supports themselves will be a little thicker than in the drawing, They will be about 1 3/4 inches thick to allow for the mortise and tenon joints to fit properly.

-The shelf supports will be made to accommodate three points of contact from the actual MDF shelves that will go on top of them. The drawing below shows two possible support designs.

The top support section will be as thick as the outside frame and allow for a slightly bigger shelf for the top of the rack.

For the shelves I will be using MDF laminated in a low pressure laminate. I will have the shelves made at a local woodworking shop where they will be cut to size on a machine, laminated, edged, and pre-drilled for spikes.

I will use these short speaker spikes, 3 per shelf on 4 of the 6 shelves. They will be installed by inserting the threaded inserts into the pre-drilled shelf holes with the points facing down which will make direct contact with the shelf supports shown above.

Small Speaker Spikes

For the feet of the rack itself I will be using these spikes.

Heavy Duty Toe Spikes

These will function as both spikes and levelers.

The color scheme that I will use will probably end up looking something like this.

Let me know what you think...

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Re: Trashing the Cabinet Idea... Building an Open Rack

So the legs are going to 1 3/4" x 1 3/4"? A bit thicker might be better if it's possible maybe 2-3". The 1 1/2" shelf supports might also benefit from some extra thickness unless they are deeper that 1 1/2" in which case you might be fine. Do you have any way to calculate how much weight each shelf will support? I'm asking out of ignorance because I don't know much about wood. If every shelf could support 50 pounds you'd be be safe for just about any future purchase. Even 30 pounds would most likely be fine. But of course if the shelf that was meant for the amp could hold a little more weight that wouldn't hurt either, again mostly for future needs. The top looks ideal for a turntable.

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paging Dr. Doug dbowker

I'm surprised that dbowker hasn't dropped by to offer his thoughts. He's a forum regular that's done some impressive DIY wood working projects related to audio.

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Re: Trashing the Cabinet Idea... Building an Open Rack

I probably messed some dimension label up... The legs of the stand will be solid 3x3 in posts.

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Re: Trashing the Cabinet Idea... Building an Open Rack

MDF can be good for shelves BUT longer than 20" and it will bow over time. It's very inert compression-wise, but not in length. You really need some way of keeping it flat, like a hardwood frame glued around it, or a support glued/screwed underneath.

Obviously, the weight of the components affect how much, but that's a big thing to keep in mind. Maple is great upgrade option- and you might be able to find pre-glued up boards (like for tables or counters) that are not overly expensive. Maple has a good sound to it as well, though I don't quite believe it's a magical as the Maple Shade studies guys make it out to be.

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Re: Trashing the Cabinet Idea... Building an Open Rack

The MDF Shelves will be laminated on all sides... veneered if you will. That will keep them from bending. Talking to my dad and uncles who are all very experienced with cabinetry and counter top building told me that laminated MDF would actually be more resistant to bending than wood. I have actually decided to reduce the dimensions of my shelves to 18x18 so the length problem won't play in either.

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Re: Trashing the Cabinet Idea... Building an Open Rack

Yes- you'll be fine at 18x18 size.

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Re: Trashing the Cabinet Idea... Building an Open Rack

Have you thought about suspending the shelves rather than supporting them with spikes? Cut two small dadoes in the underside of the shelf and run a cable across the shelf to reach from side to side of the rack structure. Or hang the shelf from the wires only at the ends of the shelf? Or, support the shelf from the sides by spikes running horizontally through the rack uprights? Or a combination of these techniques?

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Re: Trashing the Cabinet Idea... Building an Open Rack


Quote:
Have you thought about suspending the shelves rather than supporting them with spikes? Or hang the shelf from the wires only at the ends of the shelf?

Yes if someone had an accelerometer to find out what resonant frequencies they were tuning to that would be good too. Other than that it's pure guessing as he wouldn't have a reference to compare it to so he wouldn't know if he'd gotten the tension on the wires wrong. Maybe if the tension was adjustable he could do it by ear with lots of trial and error but that could drive someone up the wall.


Quote:
Or, support the shelf from the sides by spikes running horizontally through the rack uprights?

Finite Elemente does that and their racks certainly can help take a system to the next level performance wise. My only worry is that they use special spikes that I've never seen for sale that allow to really, really tighten things down. They publish numbers showing at what frequencies their racks work and the percentage of the reduction in vibrations. They use maple too.

Jan Vigne
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Joined: Mar 18 2006 - 12:57pm
Re: Trashing the Cabinet Idea... Building an Open Rack

I think you're taking my suggestions too far. I don't mean to tune to specific frequencies, that's too much for DIY. But suspending the shelves or supporting them from the side provides another layer of isolation that a hard mechanical connection between spikes facing up/down into the rack cannot manage.

THR33P4C
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Joined: Dec 29 2008 - 10:26pm
Re: Trashing the Cabinet Idea... Building an Open Rack

Just as I thought. As soon as I settle on something there is something much better lol. I did look at some suspension systems but they would be hard to do with a wood frame... plus it won't look nearly as nice as what I have planned.

I'm pretty set on this design...

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