Maximum Bass for $1000

[Patrick Bateman]

If you've followed any of my audio projects, you know I'm a total cheapskate.

I've generally had the most success when I've copied commercial designs, so I thought I'd spend this evening figuring out how much bass I can generate for $1000. In this thread I'll analyze the performance of three well regarded designs:

The Danley Sound Labs TH-Mini, a tapped horn with a 12" woofer

The JTR Growler, a back loaded horn with a 12" woofer

The PK Sound CX800, a vented box using dual eighteens

All of my comparisons will assume that we're doing DIY knockoffs of the commercial designs, to keep the cost under $1000. Since the CX800 uses two drivers that cost $800 each, we can only use a single driver. So it will basically be *half* a CX800, versus one of the other two units.

My goal is to figure out which one will make the most SPL for $1000. And this won't be designed to hit one note, I want something with wide enough bandwidth to mate up with some midbasses.

[Miguels]

am i missing something here?

first post so how could we have followed audio projects

[Triticum Agricolam]

am i missing something here?

first post so how could we have followed audio projects

Patrick is pretty active on some other audio forums. That's probably what he's referring to.

Welcome to SMD Patrick!

[Patrick Bateman]

am i missing something here?

first post so how could we have followed audio projects

Patrick is pretty active on some other audio forums. That's probably what he's referring to.

Welcome to SMD Patrick!

Thanks!

Google said this was the most active SPL forum, so I thought this would be a good place for it. I really like Steve Meade's boxes.

[Wehan]

hmmm, subcribed.

[Patrick Bateman]

First up is my 'guesstimate' of the Danley TH-Mini. I made a 'clone' of one of these already (xxx) and I'd say it's the best subwoofer I've ever built. It's quite an easy build; it's a simple tapped horn tuned to 50hz with a 12" woofer. The efficiency on this thing is just comically high; it's about 100dB with ONE WATT. To put that in perspective, the average car audio sub needs about thirty five times more power to hit 100dB!
The thing I liked about my TH-Mini was that the bass was tight and effortless. On the downside, it's so freakishly efficient, it's difficult to 'blend' in with the main speakers, and it doesn't play very low. It would be interesting to make a variant on this that sacrificed some efficiency for low-frequency output.

The graph above illustrates the output with one watt into an eight ohm load. (2.83V)



Here's the excursion and my hornresp model. The woofer is a B&C 12PS100.

[Patrick Bateman]

Here's the output with 700 watts into 8 ohms. That's 2,800 watts into 2ohms, so this probably isn't the best sub box for a car, unless you have an amp that's designed for 8ohm loads, or you can find a different woofer for this. (A couple of Alpine Type Rs would probably work here.)

This is an inexpensive build - you can get the woofer for $209 here : http://www.parts-express.com/bc-12ps100-12-woofer--294-665

[Triticum Agricolam]

Those TH-Minis are pretty awesome, I need to play with that design some time. The thing about it that's going to turn people off to it around here is the 50 Hz tuning. Most folks are going to want good output down to at least 40 hz, with 30 hz being much preferred. Still a VERY interesting design none the less.

[RooTxBeeR]

dope, subbed

[Patrick Bateman]

I was excited to see what the Growler could do. From the reviews at avsforum, it's a heck of a sub. And in a head to head shootout with the Danley TH-Mini, it did quite well.

Unfortunately, there doesn't seem to be a driver in the world that will work in this alignment, unless I'm missing something.

First pic above is the JTR Growler; second pic is the Danley TH-Mini. They're VERY similar, but the JTR is about twice as big, and it's woofer has three times as much displacement. So the JTR should really kick ass. Unfortunately, I really don't see a way to DIY this. You'd need to find a woofer with an FS of around 40-50hz, with more than 20mm displacement. I'm not aware of a woofer like that.

(JTR has their woofers made for them.)

I tried making something similar using an Alpine SWR-12D2, but the FS and the VAS on the Alpine is too low.

Basically the Growler is twice as big as the TH-Mini, which should make it about 3dB more efficient. But it *also* has a woofer with three times as much xmax. Put those two together, and the Growler *should* be able to get quite a bit louder than the TH-Mini, unless the voice coil explodes.