madisound RBR kit in a granite enclosure?

[Coconutout]

my plan was to put these brilliant babies in birch enclosure- and i've already found the material for extremely cheap here in china- 5'x8' .75" sheet of birch ply for 135 yuan- roughly $19. and was to commission the build tomorrow at a furniture factory. however after hooking up the drivers bare, and having built the statements as my last project, i didn't think i could say this again but... i am blown away by this rbr kit's clarity and especially scanspeak's bass- my words wouldn't add much to whats already an universally epic praise. but i do say that even a deaf man would be impressed by how the driver MOVES. i mean it acts like an overdriven dual coil subwoofer! and the smoothness that i thought the ribbon tweeter had forever spoiled... thank you, madisound. i will build a granite enclosure to honor this amazing deal. so i changed my mind earlier and now am looking for you guys' expertise. no doubt i'll find granites just as cheap as birch. i'm assuming/hoping that i wont need any cabinet bracings. how thin could the granite be? chamfering really necessary in case i can't? would it help to have the inner surface be rough? would it be worth it to flush mount? im thinking since it would be pretty hard to make that happen on the granite surface, i could surface mount the woofer, raise mount the tweeter with a thin ring to level with the woofer's flange and then put a layer of wood on top of the granite baffle to flush out the drivers... if i can't flush mount them. i think if they're able to chamfer woofer hole they'll probably be able to flush mount. they paint with the asphalt for damping here-http://diyaudioprojects.com/Speakers/Seas-Granite-Speakers/
would the damping materials that come with rbr build kit be ok? i saw some high density rubber sheets at the wood shop today.
yes these will be pics

[JoshK]

I've pondered this before. Cutting the granite in straight lines is one thing and not terribly difficult with a wet saw. I happen to own a wet saw and diamond blades since we redid our downstairs bathroom in marble.

However, the hard part will be cutting the driver holes and recesses as you pointed out. Just have to think outside of the box. Your ideas could work.

They make diamond hole saws as well if you have access to a drill press. I happen to just buy one of these for some porcelain tile we are using in the upstairs bath. They work well if you go slow. The recess is the only nut to crack but you might be able to do it with another diamond hole saw of different diameter.

What tools do you have at your disposal?
Do you know what kind of resin is used to "glue" the granite together?

This sounds like a really fun project!

[penngray]

The front baffle/holes etc could be cut by the granite company? They do cuts for sinks all the time.

[Face]

http://diyaudioprojects.com/Speakers/Seas-Granite-Speakers/

[TacoD]

Some speaker kits from HobbyHifi are also available in stone/ marble, see also http://www.lautsprechershop.de/hifi/...platino_en.htm

[Jed]

.. i am blown away by this rbr kit's clarity and especially scanspeak's bass- my words wouldn't add much to whats already an universally epic praise. but i do say that even a deaf man would be impressed by how the driver MOVES. i mean it acts like an overdriven dual coil subwoofer! and the smoothness that i thought the ribbon tweeter had forever spoiled... thank you, madisound.

Wow, I'm glad you like them! :T

[JoshK]

The front baffle/holes etc could be cut by the granite company? They do cuts for sinks all the time.

I wonder if they could do a recess for counter-sinking.

[Coconutout]

Wow, I'm glad you like them! :T

oh yeah, and thank you jed- first and foremost

[Jed]

oh yeah, and thank you jed- first and foremost

You're welcome, and I can't wait to see some of your pictures.

[penngray]

I wonder if they could do a recess for counter-sinking.

Some will have very nice CNC, diamond laser cutting systems so I would say yes to some.

I only know this because I spent a good chunk of money 3 years ago on granite counter tops in my kitchen and 4 bathrooms. I went to many granite dealerships to haggle as much as I could, I was amazed at some of the precision tools they had.

[Coconutout]

everything is lined up. found a shop today that will do chamfer, 45 degree edge cuts for seamless joints and flush mount, no problem. im looking at speckled black granite much like the one on diyprojects but jade marble is a lively alternative. its only going to be 210 yuan a sheet ($30) and labor even cheaper. my concern now is the brittleness of the material. the test pieces were easily shattered when dropped 3 feet to the concrete ground. not that i've ever dropped a bookshelf speaker in my life but lifting around something this heavy i'm not so confident. to that there's an added concern of international shipping when it's time for me to take them back to the states (im in china) im worried that ill find the speakers shattered like eggshells when i open up the box back home. how reliable is fragile shipping these days?... n how expensive? downright wallet breaking im sure with this weight. another option i found was faux granite. basically plastic/granite composite that's bendable with less density. id like to know if there would be any resonation (sp?) issues for being part plastic.

[Bent]

Was I the only one who chuckled when he read "counter-sink" ?

[Hdale85]

I'm wondering if adding some felt to the baffle around at least the tweeter would be a good idea.

[Coconutout]

I'm wondering if adding some felt to the baffle around at least the tweeter would be a good idea.

y? do you think the sound would be too harsh refracting off of the granite surface?

[Hdale85]

Just that granite is such a smooth hard reflective surface. I would wonder if there would be any effects from reflection or something. Was just thinking.

[Jim85IROC]

I'm not sure why it would reflect differently than any painted MDF baffle. As far as I know, paint isn't known for absorbing any high frequencies.

[Hdale85]

Because granite is much harder and more dense then any MDF. Also it wouldn't be painted and Jon and others say its better to use felt on even a wood baffle. I was just thinking out loud mostly. I'm sure it would sound great I was just curious if felt would help that much more.

[Coconutout]

my decision sways once again after seeing the granite slab shatter so easily from a 3 feet drop. wood can take more abuse than human bone but granite enclosure would basically have to be treated like a glass furniture... one drop and its back to reprinting the enclosure plan.. how much more benefit would i get in sq from birch ply would you say?

[Hdale85]

How often do you drop your hi-fi speakers?

Birch ply is very good

[JonMarsh]

If you're serious about an optimum stiff enclosure material, try aluminum. Works well for YG Acoustics, Magico, and others. If you drop it it won't shatter.

Otherwise, see if you can find LBL for an expensive but very stiff wood product.

[Coconutout]

well i've never dropped a bookshelf speaker in my life but i'm gonna have to ship them back to the states in couple months and also relocate residence several times while here in asia. thanks mr.marsh i didn't know aluminium was actually accoustically desirable material. i don't see any reason to change my mind this time. sorry for the misleading title, guys, but it's rbr in an aluminium enclosure!

am i right in thinking that i don't need any bracings with 1" thick aluminium walls?

[Hdale85]

Well....bracing wouldn't hurt but I imagine you could skip it.

[TacoD]

well i've never dropped a bookshelf speaker in my life but i'm gonna have to ship them back to the states in couple months and also relocate residence several times while here in asia. thanks mr.marsh i didn't know aluminium was actually accoustically desirable material. i don't see any reason to change my mind this time. sorry for the misleading title, guys, but it's rbr in an aluminium enclosure!

am i right in thinking that i don't need any bracings with 1" thick aluminium walls?

Aluminium has high resonance frequency which, so you want to prevent ringing. I think 1" alu is strong enough. YG designer talked about its cabinets in this thread avsforum. According to him it is very important that if you bold the panels of the cabinets (like YG does) you apply the right tension and also ensure all panels fit perfectly.

Aluminium is very stiff, but adding some tension rods, will make an even better cabinet.

[BigguyZ]

As long as we're talking about alternative materials, I've heard of using concrete....

[Jed]

MDF sounded pretty good too.

[TacoD]

As long as we're talking about alternative materials, I've heard of using concrete....

Aluminium is as heavy as concrete, only it is stronger.

[beto]

however after hooking up the drivers bare, and having built the statements as my last project, i didn't think i could say this again but... i am blown away by this rbr kit's clarity and especially scanspeak's bass

Hi coconut.. All...

I am a long time reader here but hardly post due to my inexperience on these topics as I am still learning. I am trying to understand your comment above it almost makes it sound to me, that the smaller rbr sounds better than the way larger statements, as you are blown away by their sound... I would think that these smaller speakers don't even come close to the statements in sound quality due to size and amount of drivers.. but I am not sure what you exactly mean, that's why I am asking... I am kind on interested in this kit.. but I prefer 3-ways for the obvious reasons..

[Dave Bullet]

Aluminium is as heavy as concrete, only it is stronger.

1Kg of aluminium weighs about the same as 1Kg of concrete :rofl:

[TacoD]

1Kg of aluminium weighs about the same as 1Kg of concrete :rofl:

I wanted to say that the 1 kg of alu has almost the same volume as 1kg of concrete. Density of alu is ~2700 m^3 and concrete is about 2500 m^3

Please be gentle with me, I always try to be constructive .

[JonMarsh]

Hi coconut.. All...

I am a long time reader here but hardly post due to my inexperience on these topics as I am still learning. I am trying to understand your comment above it almost makes it sound to me, that the smaller rbr sounds better than the way larger statements, as you are blown away by their sound... I would think that these smaller speakers don't even come close to the statements in sound quality due to size and amount of drivers.. but I am not sure what you exactly mean, that's why I am asking... I am kind on interested in this kit.. but I prefer 3-ways for the obvious reasons..

I think he is referring to the statements to indicate that he IS familiar with good sound, not to say that the RBR drivers hooked up "bare" are better than the statements- the SS drivers are quite clean and lower distortion than many others used by DIY, and I suspect he is responding to that characteristic, as well as the relative bass extension of the SS 5".

[Coconutout]

dont get me wrong i dont think anything can be as dynamic as the statments unless its an actual +$10k pair thats as big as them. but rbr seems more detailed and smoother in the midrange which's the area i've come to care about the most. regrettably i've still not built the cabinets but already having too much fun enjoying them bare and busy upgrading my mini tube amp instead. yes, they're being powered by meager 13w per channel chinese tube amp. so this is probably more from the tubes than anything else, even though my statements were driven with mosfets and a tube preamp also, but the mids of rbr seem to have more flesh to them. the metal tangbands always sounded too analytical and hard whatever tubes i put into the preamp- i guess in short, too metallic :P. so due to my current setup that was actually intentional (i meant to get full range horns in the beginning along with full tube setup but was reading that horns have trouble interpreting complex/fast music such as electronica which's my main genre so i was looking for a high sensitivity bookshelf with a killer mids but rbr came up as too good of a deal to pass up. i do not regret it nor miss the bass since there seems to be enough already) i cannot really comment objectively on the speaker's bass performance except that it thumps and rattles like 12" subwoofers when hooked up to my dad's crappy yamaha receivers at 120w x 2 so i know its gotta be mindblowingly loud when paired properly. in conclusion if i was to flip coins between statements and rbr, mids, rbr. highs, statements due to more detail although ringdome is just as acrobatic with speed and grace. keeping in mind that full sized statements are tower speakers that need different configeration requiring bigger space and volume than rbr, i don't think you would be regrettable for not choosing the other should you determine which setup you prefer since both are, imho, champions of their fields.