External crossover enclosure - side panels....marble or solid wood?

[treitz3]

Good afternoon, gentlemen. We have made some serious strides with the mods I am doing to my Tyler Acoustic Signature Reference speakers. If you didn't know or you haven't read before, the crossovers are being upgraded and literally everything between the output of the amplifier all of the way to the drivers are being overhauled, upgraded and custom made to make these the best of the best of this particular speaker. With that said, I have ran into a decision I'd like some input on from those who might know more than I on the subject.

What we are currently looking at building is a custom made 3/8" thick aluminum chassis that the exterior will end up being will be one piece, with the exception of the access panel in the back. Custom outriggers and spikes will also be made to order and both the outriggers and the aluminum chassis will be powder coated in black. I have had a hard time sourcing Ribbon Mahogany panels and today, I just so happened to talk with a stone shop. I told them about my project and while they normally do not do things like this, they agreed to do it and actually went above and beyond the call of duty to be involved with such a project.

I was able to find a absolutely stunning piece of granite out of an extensive collection of stone. We were able to locate a 2C stone that was about a half inch thick, probably a little bit thicker that they will be polishing the facade, edging and polishing the edge as well. When I provide the template of the sides of the actual aluminum enclosure, they can insure an exact fit. Didn't think this was possible with stone but you learn something everyday. Here's a not so detailed picture of what I could find online of the granite mined from India [not sure which mine]. The pics don't do the actual granite justice. That or the slab I saw was just an extremely eye appealing slab from the quarry. There were a plethora of "tiger eye" type effects within the granite with colors that were off the hook.

So, I'm left with a decision though I'm not sure how it would affect the final outcome of the project. The crossover enclosures will be sitting in between the speakers and they will be low enough as to not disturb the MTM drivers. The estimated weight of each enclosure is already at around 40 pounds give or take and since they both will be isolated from vibrations with each internal circuit isolated from each other on shelves made of Delrin, I do not think that the weight would be a factor but I do not know for sure. Here's my question now that you know the facts...

With the knowledge above, what would you use....solid Ribbon Mahogany [If I can locate 4 (approx.) 30"x22" panels] or the aforementioned granite slabs and what would be some possible pros/cons of each type of material?

Thanks for looking and I'm open to any suggestions thoughts or experience you may have to share on the subject.

Tom

 

[zztop7]

Thin slices of stone are bonded to structural honeycomb aluminum to minimize weight. Commonly used on flat roofs as walkways - excessive weight is minimized.

Mahogany needed another A [I am very imperfect - no slight is meant].

Best to you,
zz

 

[GaryProtein]

If you look at DIY audio, Nelson Pass has quite a few chassis cases with VERY thick aluminum walled cases at a reasonable cost. http://www.diyaudio.com/store/amplifier-chassis.html

 

[DonH50]

I'd go with granite just because it's cool and unique. Also less likely to get dinged or scratched, although your back won't appreciate it!

Will the crossover be shielded? It doesn't really matter, just curious...

 

[treitz3]

Hello, Gary and thanks for your suggestion. I decided not to go the route of a chassis like the ones you linked because these will be rather large, very large in fact. Right now, the dimensions of the external crossover unit are hanging around 28x16x21 and there are other factors like assembling it to have minimal strain on the cables and to keep all of the cabling up off the floor. Plus, I didn't want something else that looked like an amplifier just sitting on the floor.....and then there are space constraints with the current space I have available. I lost my dedicated audio room with the birth of my son, so it's currently in the living room until we move. Thank you, though.

Hello to you too, DonH50. It would definitely be cool and unique and it would definitely match the quality of the rest of the project. So far we have custom binding posts, a one piece [with the exception of the access panel] aluminum chassis that will be powder coated in black, outriggers that will also be powder coated in black, custom spikes/floor discs and a custom made plate to mount the crossover to speaker connectors and SC connections. I'm not a fan of gold, so most everything will be made with the black and silver theme. One major exception would be the two sides of each enclosure. Hmmmm, you bring up a good point about my back. If and when I ever go to pull out each crossover network to tweak or do further mods/upgrades in the future, where they currently will be located, I will have to move them. That's something I hadn't really thought about until you mentioned it. Perhaps I could place it on sliders until I know I am satisfied with the end result but I will contemplate that aspect a little bit more.

I did have a gentlemen chime in elsewhere about the use of granite and he had mentioned...

Everything I've read about it when used in audio applications (shelving, amp/speaker platforms, etc.) says it rings

That was my fear as I remember reading something about that myself. With that said, how much do you guys think the ringing will affect the external crossover and the end result given the weight of the granite? Hang on a minute....let me digress for a moment. We will have the one piece aluminum enclosure that will be braced somewhat on the bottom with the outriggers. I'll have to check with the builder to see how the shelves will be attached but they may add further bracing once installed and all closed up and we are planning on lining what we can with No-rez on the interior of the enclosure. I was figuring with the weight of the granite, that it would help to minimize any vibration or ringing and also "brace", if you will, the two sides of the enclosure....then again, how much ringing could possibly present itself on an enclosure that heavy with no moving parts or drivers to cause vibrations? Please forgive me, I'm thinking out loud here...

No, the crossover will not be shielded but now I am curious now as to why you would ask such a thing. You thinking along the lines of disrupting a TV?

Tom

 

[GaryProtein]

With crossovers of that dimension, using the granite would be cool.

I would use 3 cm thick counter top material. By my rough calculations and experience with granite counter top material your granite crossover chassis/cabinet will weigh in around 200 pounds plus the weight of electronic components. Way to go! I hope you have a good diamond bit for drilling. I wouldn't use a hammer drill with a carbide bit, or I would at least use it very carefully not to crack the granite.

It sounds like a fun project. Are you assembling the granite box with steel rods and epoxy?

How come a crossover is so large?

 

[mep]

If Gary is correct about the weight of the outboard crossovers made with granite being around 200 lbs, this seems a bit crazy for a pair of speakers that weigh 130 lbs each or even a pair of speakers that weigh 500 lbs each. Do you really want to have to deal with carrying these crossovers into your room? I don't even want to deal with amps that weigh 200 lbs each let alone a pair of outboard crossovers that weigh that much. I hope all of the money you are sinking into these crossovers will bring you an increase in the sound quality you have been enjoying with your speakers.

 

[GaryProtein]

Here is a link for the weight calculator: http://www.federalbrace.com/SupportsResources/GraniteWeightCalculator.aspx

Granite weighs about 168 pounds per cubic foot.

28" x 16" x 21" for the box is a lot of granite.

 

[mep]

I don't doubt you Gary-I just think having a pair of outboard crossovers that weigh 200 lbs each for the sake of looking "cool" is not really practical. Assuming at some point in time that Tom will want to upgrade his speakers, selling these will also not be practical unless he can return them to stock. Modified gear usually decreases in value just like cars do. Who would want to pay for shipping 400 lbs of crossovers?

 

[treitz3]

Here is a really good example of the Ribbon Mahogany that is currently on my mains...We can not use veneer because of the design. It needs to be a solid panel.

Hey, Gary. The 3CM is too big for this project and IMO, complete overkill. Even with some additional edging options that I do like, it's just too much and my back will not agree with 200 pounds. OUCH! There may be a bit of confusion either on my part or yours though. It will not be a granite box. The aluminum enclosure will be one piece with the exception of the access panel for each of the crossover networks. Only the sides will be granite or Ribbon Mahogany. We are still researching as to what type of epoxy/silicone/adhesive will hold this kind of weight [if we go with the granite] and adhere to a powder coated or a sanded aluminum substrate with the unpolished side of the granite.

One thing I'd like to make clear is that I am NOT going to do the granite. A professional shop will be handling that. All I have to do is provide the exact template for each of the 4 sides of the enclosure and they will cut each one to exact dimensions, ease edge them and polish.

The crossover is large due to the number of upgraded components going into said enclosure and the sheer real estate needed to accomplish this versus the stock components......now for something that I do not recall ever being done before.....this enclosure will actually house the original [very small real estate territory] crossover as well as the upgraded one. With the simple switch of 2 NL8 connectors on each crossover enclosure, we can swap from the stock crossovers to the upgraded ones in mere moments. Each stock crossover network will be in it's own separate enclosure within the enclosure and located on the same delrin boards as the upgraded crossover networks. Each crossover network will be secured in place with Allen bolts.

This is a fun project. I'm going insane without tunes but this project is keeping me very busy. It's amazing just how many things one has to consider when diving into a project like this but I'll be honest. I'm having the time of my life doing it. We are also contemplating making a leather bound book documenting everything that we are doing. It's a labor of love and I'm looking forward to listening to the end result after all of this is completed, tweaked and broken in.

Tom

 

[treitz3]

I was able to find a beter pic of the type of granite I'm talking about. You can't see the tiger eye effect but you'll get the general gist...

Or the Ribbon Mahogany that matches the mains....

Tom

 

[GaryProtein]

I like that you're having the two crossovers in the new cabinet so you can A-B them.

Even if you have the sides granite, that is still 4 sides, unless you mean just the left and right, in which case it is two. I think the ribbon mahogany looks very pretty. The thinnest you will get granite in those dimensions would be 2 cm. They don't make 3/8" tiles as big as the box you are making.

You may want to epoxy a piece of wood onto the walls of the granite so you can screw the electronic components onto the surface unless you want total permanence and don't care about retrievability and epoxy the electronic parts directly onto the granite.

 

[flez007]

My Ascents have the xover housed on a sealed-MDF enclosure, looks like you are on the right track using granite/wood.

 

[treitz3]

Oh, sorry Gary. There will be a total of 4 slabs altogether. 2 slabs per crossover enclosure and only on the L & R sides. From the front, you will only be able to see 3/4" of the granite [If we go that route] and the rest will be the powder coated aluminum with the outriggers/spikes extruding out of the bottom. Looking at the enclosure directly from the sides, all you will see is the granite, outriggers, spikes and cables coming out from an angle in back [when they are connected].

Tom

 

[GaryProtein]

I have to say I do like that granite. I have a floor in the house with that tile.

 

[treitz3]

Apparently, granite isn't a bad thing for this application. Even for speakers. The link below shows an interesting build and [I can't believe I am actually saying this] we are actually contemplating making an all aluminum/granite speaker enclosure as well. I will be at a meeting tomorrow to discuss the options and finalize some things with the crossover enclosure.

http://www.sdboats.com/images/speakers.htm

Tom

 

[treitz3]

Update - scratch the entire plan for this. After spending pretty much all day with the fabricator, designer and discussing possible options? We have taken a completely different route. Thank you to all that have read, responded and been a part of this.

The future looks bright.

Tom

 

[JackD201]

May your future but not sound be bright

 

[GaryProtein]

TOM, I was reading www.TheAudiophilesWife.com and saw this and thought of you.

FRIDAY, SEPTEMBER 21, 2012

Like A Surgeon


A while back The Audiophile took apart his speakers. I thought we were not supposed to touch the speakers, but apparently it is perfectly acceptable to rip out their insides and dump them in a box.

Furthermore, it is permissible, although I'm not convinced it is beneficial, to fire up the power drill and bore holes into the back of the speakers. If I understand this barbaric procedure correctly, the idea is to relocate the speaker guts into a pair of custom-made, Jatoba boxes in order to, say it aloud with me: Improve the sound quality.

I'm sure this will lead to a listening event in which I will need to convincingly say I detect a HUGE improvement in the sound quality, but until then I'm investigating how I might outboard my bladder for a more comfortable experience during the high-impact portion of my aerobics class.

And that, my friends, is audio winning.