Which Sub Box Design?

Archived from groups: rec.audio.tech (More info?)

big_qwerty@hotmail.com (Qwerty) wrote in message news:<bce008e.0408150911.77841055@posting.google.com>...
> Hey all! I got a 12" car sub im going to build a box for but its
> going into a dorm room. i got the amp and everything else worked out
> so no worries about the resitance or powering, im just looking for
> feedback on which style box to build, sealed, ported, and band pass
> are the primary ones im looking at. I have a friend who recomended
> band pass because it makes it louder, but im not always sure even he
> knows what hes talking about. Ive read all about their construction
> and all that so im just looking for feedback about what sounds good
> and will make the room shake, and since it is a dormroom looking good
> is always a bonus!
>
> Thanks!
> -Qwerty

What you are describing is a walk in the dark unless you can determine
the drivers parameters. There's lots of free loudspeaker simulation on
the net which should help to simulate what you're getting. The
parameters will determine which is best. Remember best can also mean
that a kick ass bass cabinet will be as big as a refrigerator, which
I don't think you want that. Here's a run down of the basics.

1 Closed cab: Theoretically tightest bass but does not get the most
power out of the woofer if you tend to play it near its max. (which
you shouldn't anyway)Also not the lowest bass for the size.

2 Bass Reflex: More low's per volume, a tad bit more power handling

3 Bandpass: "Adjustable" type of speaker with a built in low pass
acoustic crossover. This is important if the amp doesn't have a low
pass EQ built in. You can adjust it to be extra "loud" compared to 1
and 2 like your friend says but it will probably not go real low
unless it is big. You can also make a tradeoff by making it less loud
than 1 and 2 with extended bass response in the low's. Actually doing
this gives the most bass for size but with loudness (efficiency) and
power handling as a possible tradeoff. It really depends on how much
you push it down. If you decide to make a low going bandpass, the port
tends to get small in comparison to the cabinet which can make it
noisy. (you can hear it hoot) But you can adjust for this my putting
the right sized inductor in the pathway between the amp and the
speaker.

None of this can be acheived by guessing. Look for DIY speaker
building on the internet, or buy a book or something and get informed
before you leap. If you have to guess or just put it into something,
the closed cabinet is the way to go since it is the only one to get a
result without calculating. Remember, you need to stop highs getting
to the subwoofer or your amp has to do this. Also, Home theater amps
don't have a built in amp for the subwoofer.

Archived from groups: rec.audio.tech (More info?)

big_qwerty@hotmail.com (Qwerty) wrote in message news:<bce008e.0408150911.77841055@posting.google.com>...
> Hey all! I got a 12" car sub im going to build a box for but its
> going into a dorm room. i got the amp and everything else worked out
> so no worries about the resitance or powering, im just looking for
> feedback on which style box to build, sealed, ported, and band pass
> are the primary ones im looking at. I have a friend who recomended
> band pass because it makes it louder, but im not always sure even he
> knows what hes talking about. Ive read all about their construction
> and all that so im just looking for feedback about what sounds good
> and will make the room shake, and since it is a dormroom looking good
> is always a bonus!
>
> Thanks!
> -Qwerty

What you are describing is a walk in the dark unless you can determine
the drivers parameters. There's lots of free loudspeaker simulation on
the net which should help to simulate what you're getting. The
parameters will determine which is best. Remember best can also mean
that a kick ass bass cabinet will be as big as a refrigerator, which
I don't think you want that. Here's a run down of the basics.

1 Closed cab: Theoretically tightest bass but does not get the most
power out of the woofer if you tend to play it near its max. (which
you shouldn't anyway)Also not the lowest bass for the size.

2 Bass Reflex: More low's per volume, a tad bit more power handling

3 Bandpass: "Adjustable" type of speaker with a built in low pass
acoustic crossover. This is important if the amp doesn't have a low
pass EQ built in. You can adjust it to be extra "loud" compared to 1
and 2 like your friend says but it will probably not go real low
unless it is big. You can also make a tradeoff by making it less loud
than 1 and 2 with extended bass response in the low's. Actually doing
this gives the most bass for size but with loudness (efficiency) and
power handling as a possible tradeoff. It really depends on how much
you push it down. If you decide to make a low going bandpass, the port
tends to get small in comparison to the cabinet which can make it
noisy. (you can hear it hoot) But you can adjust for this my putting
the right sized inductor in the pathway between the amp and the
speaker.

None of this can be acheived by guessing. Look for DIY speaker
building on the internet, or buy a book or something and get informed
before you leap. If you have to guess or just put it into something,
the closed cabinet is the way to go since it is the only one to get a
result without calculating. Remember, you need to stop highs getting
to the subwoofer or your amp has to do this. Also, Home theater amps
don't have a built in amp for the subwoofer.