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Quad 8" subs for my office

OP
anotherhobby

anotherhobby

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They look great!
Love the looks!
Thank you both! I'm really proud of these little subs.

With all of them done, my total cost to build all 4 was about $1550 (including two external amps), which works out to $387 per sub (not too bad with $50 worth of fancy pants chrome legs on each one). Here is the cost breakdown:
  • $540 - 4x Dayton Ultimax UM8-22
  • $500 - 2x Used Crown XLS1500 (525 watts per sub)
  • $205 - 16x Chrome/Steel Mid Century Furniture Legs
  • $165 - 2x Sheets WIlsonart Madagascar Laminate
  • $32 - Speaker gasket & screw kits
  • $48 - 4x Speakon Connectors
  • $60 - 3/4" MDF
  • On hand items not in cost: tools, glue (wood and contact cement), 12 gauge wiring, some MDF, and lots and lots of time
 
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OP
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Yesterday I did a subwoofer torture test by playing "Bass I Love You" at high volume, and this track had no problem sending the Crown amp into clipping mode. That's the only track I've found so far that makes it clip at high volume, but I also haven't tested that much either. The Dayton subs are rated for 300W RMS and 600W MAX each, and the Crown should deliver a max of 750W to each sub pair into 2 ohms, so about 375W each. As such, I'm not terribly surprised that it clips under these circumstances, especially considering the 2 ohm load.

Also, under more focused listening, and moving back and forth, I can tell the new rear subs are ever so slightly behind the front subs in time, and a little bit of delay between the front and rear would be beneficial. It's fairly subtle, and almost sounds more "spacious" but if I roll my chair back to fall perfectly between the front and rear subs, it noticably tightens up. The rear subs are 3 feet further from my ears, so I need to add 3ms of delay to the front mains and front subs to let the rear subs catch up.

I could ignore the clipping problem since it seems to be isolated to fairly extreme examples, but now that I've keyed on the delay issue, it's annoying me. The fix requires buying another miniDSP to add a little delay, but as a bonus this opens up the ability to DSP each sub individually. This also requires 2 more amp channels, which will take care of the clipping issue as well. So for my next move, I just picked up another Crown XLS 1500 off ebay, and I also ordered a miniDSP 2x4 HD.
 
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Digby

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apologies if already answered, but why the legs...to stop the drivers being accidentally booted?
 
OP
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anotherhobby

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apologies if already answered, but why the legs...to stop the drivers being accidentally booted?
Yeah, I mentioned in the first post, but it's a long one and easy to miss this little bit between the pics:
From there I was able to mount the driver for a test ride to see how it would sound. I hooked them up to a Crown XLS1500 that I got used for cheap off ebay (525 watts per channel into 4 ohms). I was able to test them different heights, and they actually measured best about 6” off the floor. That's great because I wanted the subs up on legs for several reasons. They would lift them up out of the toe stubbing zone, it’d make them easier to move when vacuuming the floors, and I thought it’d look cool and unique. I was really happy that it measured well too!
I still feel the same way today. Love the legs, they are handy for moving the subs around when needed, and they have kept me from stubbing my toe on one of them. :)
 
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