skool project

[pinkfairy]

im makin a sub box with a cross over circuit. can anyone help me with these questions?

What size box is best for a 15 inch subwoofer?
How much is the box and circuit likely to cost?
What components are likely to be in the circuit?
Why would you need a cross over circuit?
thanks
xxx

[BillFitzmaurice]

Box size is determined by the T/S parameters of the driver and the alignment being used.

Cost is dependant on the materials used. Something quite inexpensive would run perhaps $200 US; two to three times that would be average.

A crossover consists of capacitors and inductors, the values and component count being determined by the crossover frequency and slope.

A crossover is required to direct the frequency bands to their respective drivers and to maintain a proper system impedance.

[bhg41088]

whats this subwoofer for? I mean, it could be very, very cheap. Like a 25 watt amp and a Dayton 8" sub. That would be like a 80$ sub after the box is built.

[planet10]

Originally posted by BillFitzmaurice
A crossover consists of capacitors and inductors, the values and component count being determined by the crossover frequency and slope.

For a passive crossover anyway... for a sub it makes a whole lot of sense to use an active crossover. Often a "plate-amp" with built-in XO makes sense for a sub.

dave

[pinkfairy]

cheers!
are there any sites to help me to build this?

[454Casull]

Originally posted by pinkfairy
cheers!
are there any sites to help me to build this?

http://www.diysubwoofers.org/

As for the woodworking, it's easy enough to figure out yourself.

[richie00boy]

Do you already have the speaker?

There are certain parameters (called Thiele-Small parameters) that you can either measure or often get on a datasheet, that you need to design a speaker properly. There is not really a typical box size for a size of speaker and, if you make a vented (ported) box it becomes more elaborate, but easy when you know how

If you haven't already bought the speaker then you would be much better holding on and comparing a few different speakers using the Thiele-Small parameters.

You are in the UK and some people may recommend speakers/parts that you can't easily get over here. There are a few UK members here that know where to get good speakers and parts and I'm sure we can come up with something.

What is your application (bedroom, car?), we can help you design what is best for your use if we know.