View Full Version : Please help choosing woofer for a particular box

03-23-2009, 03:03 PM
Hello, this will be my first post to the forum so please be easy on me.

I am currently building a system in a 2nd Generation Mazda RX7 Convertible where space is at a minimum. I am starting with the sub enclosure so I do NOT currently have the head unit, amp, components of woofer. I plan on some 3-way CDT components up front and I tend toward SQ. The box has to be built to fit under the spare tire cover behind the seats. At first I thought that I would be able to build a box with enough internal space to fit two 12s or two 10s but after completing the box it seems that I will have only enough space for one woofer. The internal space of the box is just at .85sf so if I divide the box each chamber will be much less than .5. The box is a wedge type box about 27(Long) X 13(Tall) X 6.5(Deep at the top) and about 5(Deep on the bottom) with an extra piece of 3/4 MDF on the top in order to add some mounting depth. The mounting depth is about 6".

I would like some opinions on what type of woofer may be best to use for this application. I have read some about the Mag V4 that sounds good. Although I mostly listen to Rock and Techno and prefer a tighter bass note and have always used a sealed enclosure in the past, I see from reading the forum that porting may also be an option to get more sound out of the woofer. Would it be possible to port an enclosure of this size successfully. Can PVC be used to make a port?

Keep in mind that this is a convertible and the top is always down so I will always be listening in an open air environment.

I have enclosed a picture of the box in the car with an old Boss woofer in it...

03-24-2009, 04:07 PM
I think I'll go with an IDQ12D4v3.

Any opinions?

03-25-2009, 02:53 PM
OK, so now I am trying to understand impedence and figure out which amp I need. I would like to have only one 4 channel amp powering both the Components(230rms, 4ohm) and the one 12" IDQ(500rms). Space is a big issue. either the Alpine PDX 150.4 or the Avionixx800.4 would both seem good but I am confused as to which sub would work better with this setup and how to wire them up, the IDQ D4 or the IDQ D2. Will either of these amps provide enough power for these speakers or will I need two amps. If I use a seperate amp for the sub is there a benifit to a mono amp as opposed to a bridged stereo amp?