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I guess I misunderstood your intentions. I thought we were going after an acoustic piano look. Im guessing your leaning for that korglp350 look. (which looks like your typical casio stand)

Zuul, great project, and I agree with your comments about MDF. I've built many a bookcase and paneled cabinet door with the stuff, and it's great. One good thing about it is zero preparation for painting and then the painting results are outstanding. It won't take end-screwing without splitting, so watch your design there.

For speakers, my son just loaned me his Rocket 6 powered monitors for my DP at home. Wow! What a sound! If I were doing what you are doing, I'd make space in the cabinet at around ear level for a pair of these.

Looking forward to postings from you about your progress.

craig1999871,

No, you didn't misunderstand. I do want an acoustic piano look. But after thinking it over, there's no sense in making the area from the keyboard down look like a piano. It'd be empty space, extra weight, and wasted materials. So, basically it'll be a sort of half piano type thing. An L shaped cabinet with a lid. Who knows though, I may like how it looks and build the lower part to match. Either way the top half will be the same. Shouldn't be too difficult to add a rectangular box for the bottom if I change my mind. It may turn into a large pile of crap. ....we'll see. ha


coker,

Thanks. Yeah, I hear those are pretty sweet monitors. A guy at my work does a lot of recording for local bands and he recommended those to me also. For right now, since I'm still learning and those cost a bit much, I'll just use some 2.1 computer speakers. I don't play much without headphones anyway.

I've read about MDF and it's hatred for end-screwing so I got a bunch of L brackets for those areas. Glue and those should do well enough. Did you have any troubles when sealing the edges of the MDF on those bookcases?

Zuul

Zuul, edges seem to paint up just fine. I haven't noticed any sealing problems.

If you have a router or a table saw, you may want to make a slot in one panel to accept the edge of the panel that meets it at a 90 degree angle, if you know what I mean. This would have a cleaner look than L brackets and enable you to glue the two pieces together.

Coker

I decided to go the "real" approach for my cabinet. I picked up a 1922 Adam Schaaf 5 foot baby grand for free after advertising on the local buy and sell for a broken one. I am currently stripping it down to refinish it. I removed the harp and keys and am left with the empty box now. The following pic shows the locations that I am placing four 6 inch woofers and four dome tweeters, with two 12 inch drivers for the bottom end.

Fantastic! Tell us what you do with all the metal you removed from it. Do scrap yards take that stuff?

Well, I had a friend with a truck and snowmobile trailer. I was amazed at how little the cabinet weighs in comparison to the harp and keys. I didn't actually weigh it but that sucker must be close to 150 lbs. He was going to take it to the scrap dealer but as far as I know hasn't yet.

CMac! That's going to turn out really nice. I'll be looking out for updates for sure.

I had a little time today to get some work done before it got all crappy outside. Here's what I've got...



I put everything in the garage, cleaned up, came in the house and felt pretty good about the progress. Thought all my cuts were made. Yeah.... Forgot the damn top! Oh well, still good progress nonetheless. MDF is awesome to work with, aside from the dust. It cuts so nicely.

1) those 2.1 computer speakers are about the worst choice for digital piano. Even some way-cheap monitors would be better. the low-end 2.1 system is lacking in the exactly the range you play most on a piano. You need something with at least a 4.5" driver on the left and right side.

2) if gluing MDF it's best to make some kind of self aligning joint either with a router or dado blade on the table saw. but joints just have zero holding power.

Dowels work really well and are cheap and easy. If you plan to cover the MDF you can be really simple and drill from the outside and hammer the dowel in like a nail then hide it with wood filler. If you plan to paint you need to drill two holes from the inside of the joint and glue the dowel into one part before assembly.

3) The best way to finish MDF is by covering it up. The Tolex idea was good. Wood veneer is more common or even formica. Lacking any of that it's paint, sand, paint, sand, paint repeat as required.

4) better then l-brackets are 3/4" cleat blocks. Strips of 3/4" square hardwood that you glue and screw to inside corners.

How will you drive these speakers? I guess you'd need a rack of amps but I think the most critical part will be the way the stereo signal from the DP is crossed over to the many driver channels.

When Yamaha built the N3 Advent Grand they were able to sample an acoustic piano with a mic placed at every speaker location so each speaker had it's own sample set. But your system will have to somehow work with stereo samples. I've been wonding the best why to do this. What are you planning?

Didn't know that about the dowels. I like that idea. I used the cleat block way for my arcades. Very strong joint. I'm still undecided on whether to paint or cover. My wife is pretty crafty and brought this to my attention. Vinyl similar to Marshall Tolex The actual Marshall Tolex is wicked costly. This stuff looks close enough to me. I'm thinking about having them send a sample. Thank you for all your help. I'm sure that dowel thing is going to save me some headaches.

Chris, I picked up a Yamaha RX-N600e stereo amp to drive them. The amp will drive 6 channels at close to 95 watts a piece for an 8 ohm load. I am crossing the 4 sets of woofers and tweeters at 3k and just powering the 12 inchers toward the ground as is. That will use up 6 amps there. The speakers are rated for 100 watts a piece with 20 oz magnets. At this point I am planning on mounting the speakers directly to the soundboard and hoping that it does not introduce too much in the way of spurious resonant frequencies. Of course I will need to introduce a new baffle board on the bottom of the instrument to close the box. The volume of the new box will be large and I do not intend to port for anything.

As far as the imaging of the piano goes this is where I intend to hope for the best. The amplifier has a way of taking the 2 stereo channels and pushing them out in typical "surround" fashion. The left and right channels will be the far left and right as normal. The bottom drivers will be left and right from the "B" set of amps. The other two sets at the center and rear will be from the surround center and rear channels. I could have just put the 2 sets of drivers in the cabinet but a real piano is resonating from just about everywhere in the box to begin with. The sound engineer may have used a stereo or quad set of mics to capture the original sound from specific locations on the original instrument but this doesn't necessarily mean that the amplified sound will be accurately reproduced when listening on the piano bench. There are so many reflections off the lid etc that I wanted to create more of the "wall of sound" from the original instrument and let the imaging take care of itself. (If that makes any sense:) ) I owned a pair of Magnepan speakers years ago and loved the wall of sound they produce. It will be an experiment for sure.

Yes, that is exactly the way acoustic grands do it. They send sound out in all directions in three dimensions.

I'd not thought about using an A/V receiver. They have DSP inside that solves a few problems and you can buy them cheap. And I could connect my Mac to an A/V receiver with just a single fiber optic cable. (All Macs have s/pdif optical out)

Appliance Epoxy. Smooth factory-like finish, ultra hard enamel. This stuff is really nice. I put some on a scrap piece I had from the other day and I love the way it looks. Very shiny, very smooth, and only $5 a can. I've still got to figure out what method to use for sealing the edges. I've read that a mixture of wood glue and water works, or prime and sand a number of times. A guy from work told me to try using spackling. Haven't tried any yet. But something is definitely needed. The edges of this stuff are thirsty. Have a look...

I think it might turn out better than I'd hoped.

Cheers
-Z

The build went very well. I didn't seem to hit any snags along the way. Got some latex enamel, satin black for the inside. I ended up not going with the epoxy spray paint. And I'm glad I didn't. I took a chance and stopped by a local fabric store to see if they had any vinyl that would be similar to guitar amp Tolex. SCORE!! I got 9 yards of the stuff for $25. That's less than what paint would've cost. I've never covered anything in vinyl before. Having done so, I'd like to add that I dislike spray adhesive a lot. That stuff gets everywhere and stays. Anyway, here's how it turned out.

As you can see from the shots, the damn spray glue gets everywhere. No worries though. A little goo gone and it cleaned up rather nicely. I'm very happy with it. The only thing I'm still stuck on is whether or not to apply moulding. I just placed the brown trim on the finished cab and I'm not sure I like it. I think it's just because the brown looks bad against the black. I'm digging the thought of an alien green trim on black though. hmm.... I don't know. I've got some metal corners from an old Peavey amp that I still need to add but I'm taking a break for a few days. What do you guys think about adding the trim?

Thanks for having a look.
-Z

2 more.

who needs those cabinets when you can build your own a box of band aids later.

Great job, it looks really sleek.

No trim.

Nice job! How about red with a giant Nord logo?