Custom Subwoofer Box Cost?

IwantaSVX · #1 03-02-2005, 06:13 PM

I'm looking to get a custom box made to fit under the rear package tray in the trunk. Its going to have to be custom due to the small trunk of the SVX. A local stereo shop quoted me $200 to build a box to house my (2) 12" subs and fit where I want it!

I'm just wondering if that sounds like a decent deal?

Thanks

AFBeefcake · #2 03-02-2005, 07:08 PM

my sub box cost about $50 to make.

3/4 mfd
screews
spearker carpet
glue

lee · #3 03-02-2005, 09:53 PM

$200...it depends on the shape, size, and materials they will provide.

I'm guessing that AFBeefcake's box would have cost that because of the labor to build that shape plus time to work out volume and port size, etc.

Any fiberglass work will add significantly.

IwantaSVX · #4 03-02-2005, 09:57 PM

I'm looking at just a basic rectangular wood box that will be carpeted.

I don't know. I've changed 2 SVXs over to a 5spd in my garage but I don't think I would want to make my own sub box. I know they need built to certain specs depending on the output of your subs...and all that crap.

drivemusicnow · #5 03-03-2005, 02:04 AM

whats subs do you have, what power from what amp is going to them, and describe the type of bass you want to hear from them... Once you figure out the volume and type of box you want, actually designing and building it isn't all that hard. and i'm sure a bunch of us on here could help you with that.

lee · #6 03-03-2005, 02:08 PM

Quote:

Originally posted by drivemusicnow
whats subs do you have, what power from what amp is going to them, and describe the type of bass you want to hear from them... Once you figure out the volume and type of box you want, actually designing and building it isn't all that hard. and i'm sure a bunch of us on here could help you with that.

I agree. Tell us the brand and model of the sub, if you want sealed or ported and I'll give you the dimensions for a simple box (you have to say where in the car you want it located, i.e., under the rear package tray or ???).

Don't have a saw - no problem. Have Home Depot or Lowes cut it to size for a buck or two (they sometimes charge after the first couple of cuts), a little glue & a couple of screws, some carpet from Autozone, a few staples or contact cement to hold the carpet ... less than $50.

BTW, I couldn't find a good match locally for the SVX carpet so I went to a graphics shop and got a few sq feet of vinyl and covered the box that way - they even had the SVX logo so I had that cut in a contrasting color and stuck that on the box. I have a saw, but the total cost was about $20 for a simple sealed box to hold two Infinity 10" woofers.

IwantaSVX · #7 03-03-2005, 04:17 PM

Going with 2 infinity 1200W 12" woofers. I talked with another local shop and they quoted me $100-$175. I'm probably just going to let them build it for me.

Since there is only a clearance of about 12" from the carpet to rear package tray.....I'm being told the box will have to slant on the front. So, I don't have the first clue about mitering the angles and all that good stuff.....I'll just let them build it.

Earthworm · #8 03-03-2005, 05:55 PM

I got mine as a package so I don't know how much the box itself cost. It's probably as small as you could go for my 2x 12W3's.

kuoh · #9 03-03-2005, 08:26 PM

In case anyone else is shopping for an upgrade, Crutchfield has some Infinity Kappa Perfect VQ subs for around 50% off right now. I just got myself one!

KuoH

IwantaSVX · #10 03-03-2005, 10:32 PM

Thanks for the help everyone. I'm not an audiophile. I've talked with Jimsbaby about the wiring and amp. I'll paste the specifications on the subs below. I went with the Alpine 9831 head unit....which seemed like a good choice I'm going to be running 4ga power and ground wires from the battery and a 1 fd cap.

I'm just wondering what everyone else would recommend for an amplifier to power these two subs?

Peak Power Handling- 1200 watts
RMS Power Handling- 300 watts rms
Frequency Response- 20 hz-250 hz
Impedance- 4 ohms
Sensitivity- 92 db
Size- 12"
Dual Voice Coil- NO
Voice Coil Design- Single Copper
Free Air Resonance- 29 hz
Sealed Box Volume- 1.25 cu ft

I went with these subs as the price was right and everyone that posted a review seemed to be more than happy with them. I quote (from more than just a few reviews) "NO DISTORTION, CLEAN-SOUNDING BASS, DURABILITY IS AWESOME." A handful of people say that they've had no problem overpowering them with very little to no distortion at all.

Any pointers for me when I'm shopping for an amp? I'm probably going to go Ebay for one as I'm definitely not impressed by any of the local audio shops retail prices! I just don't know what power output to be aiming for, as I've had everyone tell me something different (some talk about bridging and stuff that just goes in one ear and out the other).

kuoh · #11 03-03-2005, 11:26 PM

Try Audio Warehouse Express I've ordered many components from them and have never had any problems. In fact, I just ordered the Pioneer DEHP770MP from them a couple of days ago.

KuoH

lee · #12 03-04-2005, 01:39 PM

First, you need to match the amp to the head unit. luckily, your head unit puts out 4 volts - a kind of middle ground and safe value. then you need an amp that puts out 500 watts RMS into two ohms (what the 2 woofers will be when connected in parallel) when driven by a 4V signal.

A pretty good amp, and almost always available, would be the Rockford Fosgate 501BD. The Power series is pretty reliable and I've never heard of one not making rated power.

Of course if money is no object.....

IwantaSVX · #13 03-04-2005, 04:57 PM

Ok, its becoming clearer.

Now, what I'm not clear on is: Say I have an amp that puts out 500 watts rms @ 2 ohm like the one you suggested. Now that is a mono amp (1 output). Therefore, wouldn't I need to wire the subs in series to spilt the 500 watts between them?

Now, you said that the 2 ohms comes from the 4V signal and subs in parallel. So, wouldn't I need an amp that is at least a 2 channel rather than a mono amp (because I would have to wire them in series to split the power)?

lee · #14 03-04-2005, 05:33 PM

Quote:

Originally posted by IwantaSVX
Ok, its becoming clearer.

Now, what I'm not clear on is: Say I have an amp that puts out 500 watts rms @ 2 ohm like the one you suggested. Now that is a mono amp (1 output). Therefore, wouldn't I need to wire the subs in series to spilt the 500 watts between them?

Nope, wired in parallel on that amp and each gets 250 Watts of the 500 Watts with 2-Ohm load. Wire the subs in series and it becomes an 8-Ohm load as seen by the amp - and for that amp you would get around 125 Watts (so each sub would receive 62.5Watts).

Quote:

Originally posted by IwantaSVX
Now, you said that the 2 ohms comes from the 4V signal and subs in parallel. So, wouldn't I need an amp that is at least a 2 channel rather than a mono amp (because I would have to wire them in series to split the power)?

Sorry, maybe I wasn't clear enough. The 4V is an input to the amp from the Alpine headunit and some amps (mostly old-school) can only take say 2volts on their input side. Just about any recent (and decent) amp works with a 4V input. The idea is to maximize the output of one device consistent with the input of the other both for best signal to noise ratio and for easiest gain setting. I'm guessing my description still sucks.

Here's what I think is the best tutorial car stereo site on the net: http://www.bcae1.com/

if you look through it, it will explain better using graphics. For example, scroll down the right hand side of the site to topic #58 and give that a look.

IwantaSVX · #15 03-04-2005, 05:42 PM

Thanks so much Lee. You helped a great deal. I catch on really quick....but when everyone tells me something different....all goes in one ear and out the other.

So, basically one choice is a mono amp with a decent output for a 2 ohm load. I will have to wire the subs in parallel at the amp in order to split the single output, right?

Now, say I find a 2 channel amp. I'll be looking for one with a decent ouput for 4 ohms now???