Hi, newbie here, sortof... not sure where to post this, way too many subforums, heh...
I have a handful of small generic speakers & while they aren't showstoppers, I would like to Optimize their sound by building a cab around them. Can someone point me to some places that will give me correction calculations of dimensions (LxWxH)? Perhaps that is all I will need to do at my stage of knowledge/experience, i.e. build a PROPER cabinet, install speaker, then straight wire them up to an amp sound source. I have built a speaker before but that was in the late 1980's.
Here are the speakers in question:
- 3.0 inch (frame), 4Ω, 8P307TA (there is a logo on speaker but not sure what it is), wattage unknown, smooth silver plastic dustcap, 2 pieces.
- 2.5 inch (frame), 16Ω, no model#, TopToneJapan, 2 pieces (may not use these)
I also have a couple tweeters that if I had time I may also design into the computations:
- DP-Audio DW51 tweeters, crossover built in, impediance unknown, 2 pieces, see Fry's Electronics |
I have actually breadboarded the 3.0-inch speaker & DW51 tweeters last year, in stereo config & I thought they sounded ok, but that was without a cabinet. I realize they may have different impedances, I don't recall what "resistance" I measured of DW51.
I have read the Radio Shack "Building Speaker Systems" (2nd Edition Paperback – 1991) that I read in the early 1990's, but their golden ratio calculations don't go far down into the 2-3 inch speaker sizes, iirc.
Any thoughts? I just want to build a quick cheap (but optimized) PC/shelf speakers out of these items. Thanks. If anyone needs photos of these mystery speakers, I can do that if requested.
I have a handful of small generic speakers & while they aren't showstoppers, I would like to Optimize their sound by building a cab around them. Can someone point me to some places that will give me correction calculations of dimensions (LxWxH)? Perhaps that is all I will need to do at my stage of knowledge/experience, i.e. build a PROPER cabinet, install speaker, then straight wire them up to an amp sound source. I have built a speaker before but that was in the late 1980's.
Here are the speakers in question:
- 3.0 inch (frame), 4Ω, 8P307TA (there is a logo on speaker but not sure what it is), wattage unknown, smooth silver plastic dustcap, 2 pieces.
- 2.5 inch (frame), 16Ω, no model#, TopToneJapan, 2 pieces (may not use these)
I also have a couple tweeters that if I had time I may also design into the computations:
- DP-Audio DW51 tweeters, crossover built in, impediance unknown, 2 pieces, see Fry's Electronics |
I have actually breadboarded the 3.0-inch speaker & DW51 tweeters last year, in stereo config & I thought they sounded ok, but that was without a cabinet. I realize they may have different impedances, I don't recall what "resistance" I measured of DW51.
I have read the Radio Shack "Building Speaker Systems" (2nd Edition Paperback – 1991) that I read in the early 1990's, but their golden ratio calculations don't go far down into the 2-3 inch speaker sizes, iirc.
Any thoughts? I just want to build a quick cheap (but optimized) PC/shelf speakers out of these items. Thanks. If anyone needs photos of these mystery speakers, I can do that if requested.
Multiply the advertised diameter by 1.1, then cube that; this will be a workable volume. Don't make H W and D all the same.
3": 3*1.1= 3.3. 3.3^3= 36 cubic inches.
2.5"x3.6"x4" might be convenient.
Panel thickness may be 1/25 of panel width, so 1/8" or 3/16" stuff.
3": 3*1.1= 3.3. 3.3^3= 36 cubic inches.
2.5"x3.6"x4" might be convenient.
Panel thickness may be 1/25 of panel width, so 1/8" or 3/16" stuff.
Thank you for your response (1 person out of 86 views, so I'm grateful). I have some pressboard, I think that's what it's called, or maybe wood paneling, that is 1/4" thick, glossed on 1 side. Would that be ok? It's the only thing I really have just lying around. It's 8" x 48" and with your calculations I really only need about 70 square of it. This is my first build in a long time.
Umm, 2.5" the depth, yes? And I assume 3.6" is width & 4.0" is height.
If I decide to stick those tweeters in there, do the dimension computations change?
Btw, I never really thought the reason why all of the cab sides should never be the same. May I ask why? Something about reverb? I guess I should re-read that Radio Shack book. 🙂
Don't over-think. You want a closed (sealed) box so the back-side radiation does not cancel the front radiation. Not real small or you cramp the bass.
> all of the cab sides should never be the same
Take a paper-towel tube. Clap your hand at the end. The pitch of the "thump" is related (by speed of sound) to the tube length. Same happens between parallel walls. In a box you have the option to not have all three thump-pitches the same. Conventional Wisdom says you should not make them all the same.
Stuffing (for this size, true wool socks or blanket snips work great) damps the thump. A stuffed box will never sound like three towel-rolls.
And several very popular speaker systems are "cubes".
> all of the cab sides should never be the same
Take a paper-towel tube. Clap your hand at the end. The pitch of the "thump" is related (by speed of sound) to the tube length. Same happens between parallel walls. In a box you have the option to not have all three thump-pitches the same. Conventional Wisdom says you should not make them all the same.
Stuffing (for this size, true wool socks or blanket snips work great) damps the thump. A stuffed box will never sound like three towel-rolls.
And several very popular speaker systems are "cubes".
Thanks for your input.
Where would I find circuit theory for a 2.1 surround sound system? My guess is that the signal going to this single bass speaker is a combo/summing (amp) of the left & right signals, then through a low pass filter, then to a separate power amp.
That is: L+R summing amp > Lo-pass filter > audio amp > speaker. Would that be about right?
Speaking of that, that speaker that I said I built long ago happens to be a cube (and I still have it), just probably not optimized in its dimension measurements. However, I might be able to use that as a lone bass speaker, in between the 2 main speakers. I have already tested this cube speaker, running an audio signal from laptop to a low power amp (~2W), then in my audio software, I just reduced all frequencies except the lowest, around 60hz, and it sounds good, not bad or great, just good, for the moment, in this experiment.
Where would I find circuit theory for a 2.1 surround sound system? My guess is that the signal going to this single bass speaker is a combo/summing (amp) of the left & right signals, then through a low pass filter, then to a separate power amp.
That is: L+R summing amp > Lo-pass filter > audio amp > speaker. Would that be about right?
- Status
- Not open for further replies.