I am currently in the process of (slowly) building myself a budget system for my 95 Z28. The next step in the project is to deal with the sub component. I have determined that I like the custom 10" enclosures (MTX and Stealthbox, currently favoring stealthbox due to budget). The volume of both of these enclosures is listed as 0.6 cubic feet. So I went to Crutchfield and looked at a couple subs (for information purposes only), downloaded the Theile-small parameters and calculated the Qtc. Assuming I am going for as close to 0.707 as possible, I found the Infinity Kappa Perfect 10.1 was a decent match in this regard (calculated Qtc=0.714). I can get this sub for like $85 on ebay. Can anybody recommend a sub that would produce a similar response curve for less?

Finally, I'd like help in choosing an affordable amp for this. I'm thinking I want at least 200W rms into 4-ohms, but I don't need a ton, because the car speakers are going to have to live with the head amp (but with a DSP high-pass to make better use of the little available power). Any ideas? The MTX 6500d looks decent...

 

The 6500D is a great subwoofer amp. I've got mine hooked up to a 10" Alpine Type-S running at 2ohms and it sounds great! If you get one I would recommend running it at 2ohms to get the most power out of the amp.

 

That's just a matter of getting the dual voice coil version (assuming each VC is 4 ohms), right?

Anybody else for an amp or sub recommendation for this small sealed box? I'm not married to the Kappa Perfect. How about comments on the desired Qtc?

 

For a single sub yes, dual 4ohm VC's in parallel is what you want.

I wouldn't sweat the Q thing. A Q from .7 to 1 will sound good in just about any car due to the added cabin gain.

 

I ran some numbers for the Alpine SWS-1041D and SWS-1042D.
In a 0.6 cubic foot enclosure, their Qtc's are 1.178 and 1.0424, respectively. The -3dB cutoff for each is 43.5Hz and 41.5Hz, also respectively. That's pretty decent performance for a really small sealed enclosure. Which do you have?

 

I'm currently using the JL Audio "Vantage" Stealthbox.

 

Well what sub do you recommend for a small sealed enclosure (0.6 cubic feet)? The Alpine SWS-1042D seems like a reasonable choice.

 

I'm very happy with my Alpine Type-S. It blows away the JL 10W3 I used to have. The JL is a great sub but the Alpine seems to be a better match for the Vantage Stealthbox.

 

I've been compiling a list of subs with a bunch of relevant TS parameters. I'm looking at Qtc as it compares with the f3 and fc, mainly. The idea is, if the Qtc is on the high side (0.9 or 1), then f3 and fc better be lower.

I'm curious about comments on this spreadsheet. Please give them! Anyone!

Subs for a 0.6 cubic inch box

 

I did not look at your spreadsheet, but keep in mind QTC is a good guide to go by, but i have heard some subs that shouldn't have sounded good in the box i had them in, but did. The IDSPL 15 in a 1.35 cube sealed box is music to my ears, definatly a top notch sub, but it would have taken a 20 cube box to get a .707 so take QTC with a grain of salt.... use it as a general guide, but not an end all of how accurate a sub is going to be.

 

My goal is achieving a flat response to 20hz or so. So I think my question really is, what is the cabin gain curve of a 4th gen camaro like? I just want to match the falling slope of the response curve with the increasing slope of cabin gain to net a flat response. That's why I'm focusing on the Qtc. I also don't know where I want my fc and f3. I was initially thinking lower, but I am also in "home theater" mode where there's no cabin gain. Help!

 

QTC isn't going to help you with a flat response (it does help determine transient response), F3 is what you want to look at, but since our cars have some pretty substantial cabin gain it reallydoesn't matter either. Basicly you aren't going to know what is flat unless you put it on an RTA, The best you can hope for is a little trial and error... or better yet just go for a proven setup and if it doesn't suit you change the box volume. Most any sub can be made to play relativly flat with a bit of tinkering, but since you are space limited i think you are looking at the right subs, from there it is all personal preference so someone's opinion is going to be of limited use... $85 for the perfect sounds like a good deal to me, if you want to go cheaper you aren't really going to get much more for less $$. Once you start going cheaper than that the choices become pretty limited if you still want it to be close to the same quality as the perfect.

 

I been down the stereo road before.....

A system that is matched up well will work just as good as a high dollar system will.

In my Trans-Am i run a 1600watt Boss Audio amp. 2 Channel. And it pushes my 2 10s awesome. Boss is far from the best but works great for me, i can get those amps for 140.00,

 

I decided to make some purchases.
I went with the Alpine Type-S sub (SWS-1042D), MTX 6500D (crazy power at 2 ohms) and Subthump's custom enclosure. I think I'll be happy. This will be WAY more than enough to work with my currently-head-unit-powered Boston Acoustics FX6s.

Any thoughts on amp mounting? I'd prefer to keep it behind the cargo cover, so it's hidden when the hatch is closed. For the winter I'll probably keep it in the t-top floor area and worry about an amp rack in the spring.

 

Maybe something like this...

Spare Tire Amp Rack
Amp Board
Hook & Inverted Wing Nut

This is from a setup I had when I first bought the car. The board is held to the spare using long nylon wire ties. I kept a small set of wire cutters and a screw driver in back in case I ever needed to remove the amp to use the spare. I had to flip the spare around so that I had more mounting depth. I also got a piece of threaded rod to make a shorter hook thats used to anchor the spare to the car.