Adding a Sub

[THRobinson]

So... from a previous thread, my TPA3116 50wx2 amp came, and actually not a bad unit. Tested with 12v and worked fine, but plug was 5.5mm x 2.1mm, stanard AC Adapter size, not laptop power supply, plus the Sanyo capacitors on it were all fakes. Won't improve anything but for poops'n'giggles I'll recap with Rubycon to avoid any issues, and solding in a new plug for my Compaq PSU.

Anyways... may use those for a bartop I am making my niece.

I was grabbing a Logitech X-230 someone has used for $5. I think they'll sound better.

I plan to add the left/right speaker at the top where they other speakers were going to go, but since won't look quite right, I plan to make a wooden frame from some 1/2" x 1" pine, and stretch black cloth over it and keep it in place with velcro. Hide the speakers fully, but, volume knob access if ever needed.

The sub... is where I'm looking for some advice.

If you see this thread... you can see my design plans. They have changed a bit since then, like a single door front with no knobs.

http://forum.arcadecontrols.com/index.php/topic,154681.0.html

Ideas for the sub basically come down to 2 options that I can think of....

1) Leave the sub in the box, cut a hold in the back for the speaker to face out and basically have it on one of the shelves at the bottom. Unlikely enough room on the shelf behind the monitor where the motherboard and such is.

2) Gut the sub. Take the top shelf and wall it off halfway. So that top shelf is half depth. Front half is still ok for storage, back half though would be essentially an enclosed box. Mount the sub speaker centre/back facing out, and on either side towards the outside edges at the back, ports. Maybe line the inside of the box with some sound insulation.

Basically... cut a hole and stick the sub as-in inside, or, gut the sub and build it into the cab itself.

Any thoughts? ideas? would it sound worse if I mess with it and make the enclosure bigger?

[lilshawn]

you will have to either....

1: leave the sub in the box and install as is.

or

2: Build an exactly comparably sized space in the cabinet for the sub and transfer the port and everything to that space/


subwoofers operate in a "tuned" enclosure. changing that enclosure changes the operating response of the woofer. straying from the original design will affect performance negatively and greatly. with such a small airspace to begin with even a few cubic inches either way difference can kill the response curve boost that the woofer is relying on. Without knowing the exact TS specs of the woofer you couldn't begin to design a new enclosure for it without a whole lot of trial and error and output measurement.

I mean, you can futz it and see what happens of course.

[barrymossel]

Making a ported subwoofer enclosure bigger (or smaller) won't work if you don't calculate it. I would just use the current enclosure as that's optimized for the subwoofer + vent.