In the fall of 2010, I was driving the kids to choir practice, and I saw a bunch of public-address horns and drivers sitting on the curb. I pulled over, hopped out of the car, and asked the man raking leaves whether he intended to be giving away the gear for free. He said he was, so I wedged it all into the back of my van and got glared at by the kids. I was now in a position to wheel-deal myself into a LeCleac'h system. I sold two of the horns and one of the drivers, along with a bunch of other old gear.
Step 1: 800-8,000Hz: Azura AH-425 Horns
Once I had the money together from the sold-off salvage, I immediately ordered a pair of his AH-425 horns, which were designed for the remaining pair of salvaged Altec 288C drivers.
The horns simply bolt onto the drivers, so there's nothing to "build" here.
Those drivers on those horns cover (conservatively) around 800Hz to around 8,000Hz, so I still needed to cover 30-800Hz and 8,000-20,000Hz:
(The photo for this step is from Martin's website.)
Step 2: 30-70Hz: Dayton SUB-120 12" 150 Watt Powered Subwoofer
Step 3: 8,000-20,000Hz: Fostex FT17H Supertweeters
That's 8,000-20,000Hz covered. So now we've got:
Step 4: 70Hz-800Hz: JBL 2225H Woofers in Bass Reflex Boxes
I used WinISD to design some 3ft3 bass-reflex boxes tuned to 40Hz, and then manipulated the cabinet dimensions (keeping the volume constant) so the boxes would fit inside the built-in cabinets in my office (if I un-mounted the cabinet doors).
The 2225 data sheet specifies a "highest recommended crossover point" of 1,200Hz, so these should cover my 70-800Hz range:
80Hz-800Hz: JBL 2225H Bass Reflex
I'll detail the cabinet build in the next few slides.
Step 5: Cutting the Panels
I don't own a table saw, so I wrote up a cut plan and used a circular saw with a fresh carbide blade, a tape measure, a big L-square and one of those nice clamp-on straightedges from Rockler. My panels actually turned out more square than the last couple of times I've cut big panels on a table saw.
Step 6: Join Panels With Biscuit Joints
I used WAY too many biscuits, as you can see...but the process was very satisfying and worked great!
(The one thing I would do differently next time is that I would adjust the joiner so the panel edges come out just slightly proud, and then trim them off with a router after glue-up. My joints this time were wacky by a 32nd of an inch in some places, and I'd prefer to avoid that.)
I used regular yellow wood glue.
Step 7: Paint Five Sides With DuraTex
- I like the way DuraTex looks
- I didn't want to spring for enough veneer to cover all six sides
- Those five sides were going to be hidden by the built-ins anyway.
Step 8: Cut Baffle Holes
Step 9: Apply Veneer to the Front Baffles
I sanded the veneer carefully and finished it with "natural" color Watco Danish Oil, then glued the baffles into place.
Step 10: Install Bracing
Step 11: Install Insulation
Step 12: Mount Woofers, Port Tubes, Terminal Cups
The woofer boxes are DONE!
Step 13: Hook Everything Up
What's going on in the photo is:
The iPod (full of 256K VBR MP3's) runs to the TCC TC-754.
The TC-754 runs to the Rane.
I have the Rane set up to split the audio signal into three chunks: 0-70Hz, 70-800Hz, 800Hz and up.
The 0-70Hz chunk goes to the subwoofer.
The 70-800Hz chunk goes to the Dayton DTA-100 30-watts-per-channel amplifier. The DTA-100 goes to the 2225 speakers.
The 800Hz-and-up chunk goes to the Sonic Impact T-Amp 6-watts-per-channel amplifier. The T-Amp goes to both the Altecs (via an L-pad that pads each Altec down so it's the same volume as its supertweeter) and the supertweeters (each via a capacitor, which keeps sub-8K frequencies from hitting it).
Step 14: Conclusion
I'll be messing with the exact crossover points and levels for a while (and I'm itching to repair a couple of my vacuum-tube amplifiers so I can swap them in), but I'm losing a lot of sleep listening to music, and that's my baseline for a successful system!