Car audio in the home!

[thethriller]

Let me preface this by saying this is no professional build, it is based on leftover junk and boredom

So a while back I had 2 RF P2D28's in a slot ported enclosure on my previous Alpine MRP-M500 (@ 2Ohm). They were fairly impressive on ~500w in my hatchback 1999 Mercury Cougar until one of the surrounds delaminated. (I replaced them with a 3rd gen Apline Type-R 10 at recommended vented specs and it was better) So after finding some interesting reading on the interweb about using concrete form tubes (or sonotube as a generic term for this application) I thought I'd try to repurpose an odd subwoofer!

The oddball candidate, 1 RF P2D28 (8" Dual 2ohm coil circa 2009 - Keep in mind this is wired at 4ohm for this application):

So what I decided was an 8" concrete form tube was a good starting point. It has a roughly 8" inside diamater, think of it as a massive cardboard tube around 1/8" thick. If you start with a 2' section you have an internal volume of ~.69 cubes which after other displacements is pretty much exactly to RF recommended vented specs. So the subwoofer goes in the bottom, it's a double laminated pair of 3/4" MDF squares with the woofer hole and a circular slot routered into it just like the top...

The inside of the top piece, routered slot to glue in the sonotube. The port hole is here as well, 2" inside diameter port (PVC) with a recess made to glue its outside diameter inside:

And the top of that same piece of MDF, rounded over with a 1/2" roundover bit:

Painted flat black, glued and caulked, port length tuned to ~28hz prior to woofer install:

And some finished pics... the wire is simply caulked into a drilled hole. This again is no professional build, simply made for one specfic purpose:

This idea, again, started with just leftover junk. The woofer I already detailed, but the amp and power source are even more leftover junk! The amplifier is so not memorable that I don't even recall its brand. It's something like a 240W Bridged @ 2Ohm POS, it's LPF does not work so inside the tube I wired an old OLD passive crossover from a 1980's model dual voice coil 15" home subwoofer that was in the basement. The Power Supply for the amplifier is an OLD (2002-ish) 350W PC PSU, trimmed all the wires down and wired all the 12v lines to positive, and most of the grounds to negative on the amp.

At best the amplifier is putting maybe 100W to the sub as a guess... It's also possible to turn up the gains enough that the PC power supply doesn't supply enough current and I suppose the amp goes into some sort of protect? On the other hand, this little piece of leftover junk is able to easily fill a roughly 28' x 15' wide family room/home theater area with floor shaking bass for music or movies; it is actually VERY impressive on low power.

Long story short, this build is EASILY able to produce more bass than any subwoofer that comes pre-packaged with a retail 5.1 system. The home theater sub it replaced was a Yamaha branded dual sub "150W" deal. It measured approximately 24" H x 8" W x 16" D give or take, I assume it was maybe 2 6ish inch woofers ported, but haven't torn it apart. I do however remember when it was purchased as a $399 item roughly 10-12 years ago. This build literally cost about $25. The 8" concrete form tube was like $10 give or take for a 4 foot section (could build two!) I also bought some paint and caulk. Even if you include some shitty amplifier, a crappy PC power supply ($50), and the cost of this inexpensive woofer ($60?) this is a fun deal and worth every penny for a home theater sub.

For ~$25 basing it on junk I already owned it's unbelievably amazing as a home theater woofer.

[BassFiend]

I think this is pretty cool, my friend did something like this with his old 12" kicker. Yours looks way better though lol props

[SnowDrifter]

Not bad for some leftovers lol.

[bumpinTL364]

1/4 wave t-lines ftw...good looks man

[smashedz28]

Nice! Looks great.

[audiofanaticz]

looks good man!!

always wanted to buillld some audio stuff for my house, but get too damn busy doing builds for evveryone else.

Got any vids?

[CstrokerV]

1/4 wave t-lines ftw...good looks man

not a tline...

but i was going to do this never got around to it... don't think my vega 12 would make a good h.t sub

[b-eazy]

Niiiiceee and cool ;)

[thethriller]

I think this is pretty cool, my friend did something like this with his old 12" kicker. Yours looks way better though lol props

Thanks, it really is nothing impressive, but does make a nice decoration in the corner, heh.

looks good man!!

always wanted to buillld some audio stuff for my house, but get too damn busy doing builds for evveryone else.

Got any vids?

I'm not sure any sort of video would be worth taking; it's just a little sub producing bass. It sits in a corner and looks like it does. It's just better than your average home theater woofer and an example of how far one could take it with a better leftover woofer, amp and power supply.

1/4 wave t-lines ftw...good looks man

not a tline...

but i was going to do this never got around to it... don't think my vega 12 would make a good h.t sub

There are actually guidelines out there for putting woofers in enclosures like this based on how the suspension of a woofer reacts to horizontal placement for this application. I only briefly looked over them and didn't care because this was leftover junk... A CV 12 may work out just fine; I've seen some awesome designs for sonotube woofers like this using 12, 18, 24" diameter tubes as the chamber and making them into end-tables and the like.

[big dee]

That's cool as hell bro! I like it !!