thud ports

theboognish · #1 06-09-2003, 12:25 PM

Mr. Watt,
First, thank you for being such a spectacular player and role model. Your music and ethic has been an inspiration to me. I saw you at the Knitting Factory on Friday night. It was awesome, and I hope that you kick the mystery bug soon.
Now, to the question. I'm finally gonna upgrade from my traditionally crappy amplification, and I want to build a cabinet, either 2 x 15 or 4 x 12, because I have found a cheap speaker supplier, and have a decent understanding of woodworking. I know that the size of the enclosure and the size and location of ports is important, but I don't know how to determine what is right. Do you have any experience with DIY speaker cabinets, or any advice to give?

**watt** · #2 06-09-2003, 01:40 PM

hi,

it's a tough job to make a good sounding cab but maybe you're up to it - I know most folks aren't. bass really needs a well-built cabinet cuz of all the stress that's it's gonna get from moving bottom frequencies. not for the faint-hearted! I admire your pluck though...

do-it-yourself help, look down the page for cabinets:

http://www.colomar.com/Shavano/construction.html

here's a link to some audio resources:

http://www.kbapps.com/

here's harmony-central's speaker fax (1997):

http://www.harmony-central.com/Other/speakerfaq

here's a thread about folks discussing this particular subject:

http://www.olga.net/dynamic/browse.p...q.speakers.txt

something someone wrote for the bottom line list:

http://www.amstadt.com/tblarchive/VO.../bl332.html#23

rog mogale's speaker site:

http://speakerplans.com/

some audio hifi diy links:

http://www.audio-nova.com/Innehall/audionova_DIY.htm

epanorama's speaker page:

http://www.epanorama.net/links/audiospeakers.html

hope something here can help...

on bass, watt

Quote:

Originally posted by theboognish
Mr. Watt,
First, thank you for being such a spectacular player and role model. Your music and ethic has been an inspiration to me. I saw you at the Knitting Factory on Friday night. It was awesome, and I hope that you kick the mystery bug soon.
Now, to the question. I'm finally gonna upgrade from my traditionally crappy amplification, and I want to build a cabinet, either 2 x 15 or 4 x 12, because I have found a cheap speaker supplier, and have a decent understanding of woodworking. I know that the size of the enclosure and the size and location of ports is important, but I don't know how to determine what is right. Do you have any experience with DIY speaker cabinets, or any advice to give?

Subculture13 · #3 06-16-2003, 12:05 PM

One thing that I have found good too is to go to a music store with a piece of paper and a pen and a measuring tape. Find a good sounding cabinet (like an Eden for example) and just measure it and "borrow" it's design ideas. It won't help you make an exact duplicate of theirs as you'd need their drivers too, but it is certainly a good place to start to see how the pros are doing it.

theboognish · #4 06-16-2003, 01:18 PM

Mike and Renfield 808,
Thanks for the advice, links and help. After searching through the links that Mike provided, and doing some thorough peeking at other bass cabinets, I came across a book, London Power: DIY Speaker Cabinets for Musical Instrument Applications. This book suggests that the best combination of power efficiency and sound quality can be had by using a "detuned cabinet" design, where the cabinet is big enough for twice the number of speakers installed, and each speaker has a corresponding open port, that is just a cutout in the baffle the same diameter as the speaker cone.
According to the author, this design allows a cabinet with half as many speakers to be as loud as, and sound better than a corresponding sealed cabinet with twice the speakers. Apparently, this design is not used by major manufacturers mostly because of issues of profit margin and popular myths about more speakers equalling more and better sound. Plywood is cheap, so as soon as my speakers arrive, I'm going to give this design a shot. I'll report my findings when it's done.

Thanks again,
Josh

**watt** · #5 06-16-2003, 10:23 PM

hi,

make sure you use thick enough pieces of wood and it's put together really well cuz the bass will shake it intensely!

good luck!

on bass, watt

Quote:

Originally posted by theboognish
Mike and Renfield 808,
Thanks for the advice, links and help. After searching through the links that Mike provided, and doing some thorough peeking at other bass cabinets, I came across a book, London Power: DIY Speaker Cabinets for Musical Instrument Applications. This book suggests that the best combination of power efficiency and sound quality can be had by using a "detuned cabinet" design, where the cabinet is big enough for twice the number of speakers installed, and each speaker has a corresponding open port, that is just a cutout in the baffle the same diameter as the speaker cone.
According to the author, this design allows a cabinet with half as many speakers to be as loud as, and sound better than a corresponding sealed cabinet with twice the speakers. Apparently, this design is not used by major manufacturers mostly because of issues of profit margin and popular myths about more speakers equalling more and better sound. Plywood is cheap, so as soon as my speakers arrive, I'm going to give this design a shot. I'll report my findings when it's done.

Thanks again,
Josh

theboognish · #6 06-23-2003, 06:23 PM

Watt et al.,
I got the cabinet built this weekend, used 3/4" pine plywood, 2x2s, wood screws and a bunch of glue. It sounds great, and the "detuned" cabinet design is no bs. It's got plently of loud, and plenty of good. I haven't had time to start finishing it yet, but I'm gonna cherry stain and polyurethane it, and use brown internal grillcloth, so it'll look like an old radio. Should be pretty neat.
Thanks again for all the help!
Josh

**watt** · #7 06-24-2003, 04:36 PM

g,

that sounds wild! congrats! please post a shot of it when you're done.

on bass, watt

Quote:

Originally posted by theboognish
Watt et al.,
I got the cabinet built this weekend, used 3/4" pine plywood, 2x2s, wood screws and a bunch of glue. It sounds great, and the "detuned" cabinet design is no bs. It's got plently of loud, and plenty of good. I haven't had time to start finishing it yet, but I'm gonna cherry stain and polyurethane it, and use brown internal grillcloth, so it'll look like an old radio. Should be pretty neat.
Thanks again for all the help!
Josh