FitZ's soffit build project

[RICK FITZPATRICK]

Howdy guys. Well, its been a long time since I had anytime to post an update on my LONG TIME studio build But I am a working dude with little money or time, so its taken a long time to get this far. But like the saying goes..."how bad do you want it"?

Ok, this post is about my soffits. I have a ton of pictures to show you. The reason being, it took a long time to figure out how I was going to build these. Guys, my studio is in a bedroom on the second floor. This means I couldn't build a massive Monitor support system on which to decouple the monitors from the building nor from the soffit faces. I had to figure out and build a self proprietary design that would compliment my situation as well as do what they are supposed to do. That is...not transmit vibration to the building nor to the soffit faces. I spent a great deal of time figuring this out. Originally, I used Barefoots soffit design found here:
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=718
But given the space restrictions in my room, I decided to redesign the framing and decoupling details. My design utilizes a set of old Sansui speakers that I rebuilt by adding exterior mass and an interior stiffener of 1 1/4" Particle board, that I had laying around for ages. These panels were from an office partition system that someone gave me. Everything I do usually comes from collected materials. This was no exception. Mind you, I used Melamine glue and screws to fasten the massive panels. The box is of no consequence, as are the drivers, as they will be updated later, via a removable/remodeled baffle. These are only boxes, so what the hell, I don't care if their not studio monitors. As it is, they sound fucking AWESOME Anyway, here is the first phase of the soffit build. I had to do this first in order to size the monitor openings in the soffit faces. My design uses a backplane with a support system with built in decouplers. Once the backplane is in place, and insulation inserted, I then inserted the monitors. Once this is done, I can mount the bass trap(superchunk) fixtures as they die into the soffit backplanes. Once the fixtures are in place, then the soffit FINISH faces can be mounted. Here is what the superchunk fixtures will look like:
http://homerecording.com/bbs/showthr...light=Modeling
Ok, here is a few pics of the monitor Mods. Man, these babies are freaking HEAVEY...150lbs+ EACH!!







Note the routing jig in one of the pics. I built this on the monitors themselves, with a 5mm spacer in place. Once I removed the jig, and the spacers, this allowed for routing a perfect opening in the finish faces with a 5mm gap, so the monitors don't touch the soffit faces. More on that later.

Ok, now, I had built the basic soffit framing clear back during last winter. Thats how long it has taken. Although, I also did a mod to my console for a M3700 mixer, which took 4 months too! More on that in another thread.

Ok, here is the basic framing. Note that I had to build a jig for steching two strings to form the equalateral triangle for the monitoring position first. Once I had these points on the front wall, then I built a temporary monitor support to start the framing around. This all took about a week. Here is the string jig.




I took these photos after the framing was started so you see the jig as well as the framing in some.




Note that I designed these so the soffit faces were not only at 30 degrees from the room center, but also were point DOWN 7 degrees so the monitor axis was aligned vertically as well as horizontally. This created some COMPOUND MITER brain fucks. Not to mention the angles on the soffit backplanes and finish faces.






Ok, so much for that. Now for building the actual monitor supports/decoupling system, and the backplane faces/finish faces. The first thing was to cut the backplanes from one sheet of utility grade 3/4" plywood. This is a nine layer ply that is manufactured in the town of Coquille Oregon. I get this from the shop I work for. Its really good stuff and cheap too. I laid up a cardboard template right on the framing(no pic), in order to get the angles right. Although I fucked up on the first go around, and didn't level the monitor OPENINGS. Live and learn. Anyway, then I had to use a jig to cut the first opening in the back plane. The whole backplane is actually made from three pieces. The middle piece is the support system, and the other two are simply covers, although the bottom one has an opening that will be covered by fabric, as the lower half of the soffits will have acoustic HANGERS in them. More on that later. Ok, here is a series of shots showing how I machined each of these parts. Mostly, I used the first one as a routing template for the opposite side backplane and the finish faces. Then I had to go back and reroute the backplanes so the monitors fit THROUGH them. I did this with the monitor jig you see above. The finish faces compress the monitors between decoupled stops in back of the monitors and the finish face via a foam seal on the face of the monitors. I haven't got that far yet, as the superchunk fixtures are not built yet. More on those in another post. I WAS going to build those today....alas...its FUCKING COLD in the shop, so I decided to post here today instead.
Ok, here is one backplane. I used a skill saw to undersize the cuttout, so the router bit only had to cut 1/4" to the template. Makes for cleaner and easier cuts than a full bit cutout.













Once I had one backplane routed, I used it to route the opposite side.




Then I used these as templates to route the finish faces.



Then I had to go back and reroute the backplanes with the monitor template, which creates an "offset" between the backplane and finish face.


Now, once the cutouts are finished, it was time for building the support system and decoupling system.



These decoupling pads are actually a very resiliant foam, which is used for packing refridgerators for Sears. I get it free from the recieving department. Works fabulous. Only my belly tells me it works. Although I did a two day "burn in" with the monitors sitting on them to see how far it compressed. Remember, I only have a 5mm space, so once the pad is compressed, I can put the finish faces on with a 5mm spacer and VOILA!(BTW, the finished faces will be held in place via Velcro strips)






Now its time for fit check and decoupled stops installation





Now for paint, and pad tapered shim installation. Because the monitors lean forward, it places most of the weight on the front edge of the pads.
Therefore I used a tapered shim on each pad to realign the monitors to the face of the backplane.



And finally, soffit face and insulation installation. This pic doesn't show the complete installation. Only the middle panel and some of the insulation.


And here are the Soffit finish faces. Bookmatched maple.


Well, thats about it for today. Have fun.
fitZ

[RICK FITZPATRICK]

Oh, and one final pic. Listening with friends.
Dang, it didn't work.

[RICK FITZPATRICK]

Oh, and one final pic. Listening with friends.

[guitar junkie]

that is a sweet looking desk there rick!

I have now managed to get a real studio room myself, got a thread about it here also.

[VSpaceBoy]

Hey Rick that looks good, nice work. So.. how do they sound?

[MessianicDreams]

that looks fantastic!! great work - there's nothing more satisfying the good DIY work i reckon..good for the mind and soul

Any chance of some more finished pics!

[pandamonk]

Great to see your work Rick. Can't wait to see some more!

[RICK FITZPATRICK]

that is a sweet looking desk there rick!

Thanks guitarjunkie. It's still not finished. But functioning. I'm in the process of finishing the soundproof enclosure below the mixer(2 computers). Just finished upgrading one of the computers as the main workstation. Still have to reinstall it into the enclosure, install the plenums and wire them. And then add the back. Here is a few pics of the enclosure and plenums etc.










BTW, I'll be posting a complete thread on the Console M3700 mod soon. It'll take about 2 hours to upload everything and I don't have time right now. Gotta build the "superchunk" fixture frames today. Can't wait to have them finished. I've had the rigid fiberglass for over 2 months, but no time till now to build them.
fitZ

[RICK FITZPATRICK]

Hey Rick that looks good, nice work. So.. how do they sound?
Reply With Quote

Fucking AWESOME. Even with no bass traps or broadband absorption yet. Mind you, these are consumer speakers, which I use just to listen to music. Later, I'll remove the baffle and install a set of Scanspeak drivers and ...er,,,freqency dividing networks(forgot the name...ah, alzhiemers strikes again. But they're about $1k for a set I have a set of cheap studio nearfields for monitoring recordings for now.

fitZ

[RICK FITZPATRICK]

Hey Rick that looks good, nice work. So.. how do they sound?

Fucking AWESOME. Even with no bass traps or broadband absorption yet. Mind you, these are consumer speakers, which I use just to listen to music. Later, I'll remove the baffle and install a set of Scanspeak drivers and ...er,,,freqency dividing networks(forgot the name...ah, alzhiemers strikes again. But they're about $1k for a set I have a set of cheap studio nearfields for monitoring recordings for now.

fitZ

[RICK FITZPATRICK]

Fuck, did it again. How the hell do you remove or delete a post??????

[guitar junkie]

interested in seeing how things turn out

[pandamonk]

Originally Posted by RICK FITZPATRICK

Fuck, did it again. How the hell do you remove or delete a post??????

You can't

Just edit it to say "...double post..." or something

[RICK FITZPATRICK]

Just edit it to say "...double post..." or something

Thanks pandamonk. Will that delete them?
fitZ

[RICK FITZPATRICK]

You can't

OOPS. Ok. Gottcha. Thanks again.