Made these pods to fit into infinite baffled 3-way speakers. When 12" woofers extended they will suck mid-range speakers in. Problem was, pressure inside the sealed pods limited speaker excursion as 100% sealed. I thought of a simple solution by fitting PVC tubes to pods and venting them at rear of speakers thru hole... Will experiment with this idea. Any thoughts ???
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Ducts installed. Much better now. Mids sounds great. Now cones can move freely without perturbance from pods or woofers ... Decided on small hole in front of speaker for vent... I just have to half L and double C on 6dB / octave crossovers as I designed them (for mids) for 8Ω mid-range speakers. Mine are 4Ω. that might explain why I can hear holes at about 500Hz and 5KHz, which are my crossover points 😛
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TL = transmission line.
An easy (and tidy) method: cut a hole in the rear of the enclosure, and mount a section of pipe running front-to-back of your cabinet, so that, from behind, you can see the the rear of the midrange driver through the pipe.
Make it all airtight (use lots of really cheap construction adhesive: overkill only costs a few dollars), and put quite a lot of stuffing in the pipe. You can be nerdy, and 'tune' the stuffing to get a flat impedance hump, or simply jam in a couple of old shirts and call it a day.
This is my ASCII art representation of what I mean. If it doesn't display OK on your phone / mac / palantir / scrying pool, just use your imagination:
|=============|
|.............................|
|------------------------|
> mid xx stuffing xx hole
|------------------------|
|.............................|
|.............................|
|.............................|
}.............................|
}.............................|
woof........................|
}.............................|
}.............................|
|.............................|
|.............................|
|.............................|
|=============|
Another thing: "Much better now. Mids sounds great."
This could be for more reasons than you realise: you've also changed (and possibly improved) the sound of the woofer, since there's now a big, stuffed hole in the cabinets.
An easy (and tidy) method: cut a hole in the rear of the enclosure, and mount a section of pipe running front-to-back of your cabinet, so that, from behind, you can see the the rear of the midrange driver through the pipe.
Make it all airtight (use lots of really cheap construction adhesive: overkill only costs a few dollars), and put quite a lot of stuffing in the pipe. You can be nerdy, and 'tune' the stuffing to get a flat impedance hump, or simply jam in a couple of old shirts and call it a day.
This is my ASCII art representation of what I mean. If it doesn't display OK on your phone / mac / palantir / scrying pool, just use your imagination:
|=============|
|.............................|
|------------------------|
> mid xx stuffing xx hole
|------------------------|
|.............................|
|.............................|
|.............................|
}.............................|
}.............................|
woof........................|
}.............................|
}.............................|
|.............................|
|.............................|
|.............................|
|=============|
Another thing: "Much better now. Mids sounds great."
This could be for more reasons than you realise: you've also changed (and possibly improved) the sound of the woofer, since there's now a big, stuffed hole in the cabinets.
Thanks hollowboy and GM.
"Another thing: "Much better now. Mids sounds great.""
The mids weren't happy being sealed in a small box! Venting with all of 4-5mm tube was just enough if I pushed the cone in, it would return (relax). Prior the speaker cone could not move much at all. May be I fluked something (there is first time for everything) but I think it just allows more cone movement.
Nothing serious, just experimental!
My friend has some really nice big speakers (6" high and must be 180L volume or something). He insisted on base reflex holes for extra bass but I tried to insist not to. He used some nasty technics 3-way crossovers. I am building some nice 12dB / octave ones with air-cored inductors for him. They will sound much better and "flat" without the reflex hole.
My speakers are just experimental. Nothing flash. They do sound good to me now. the goal was to "upgrade" with budget of $0. So far I am pretty much there! DIY is a good way to learn. I revised up on math too. I have generated all the math to verify I am on the mark.
Equals 500Hz for low pass... 😎 Tried to use scientific (engineering) notation to 3dp. I have also calculated the hp filter (5KHz) I must sit down and calculate the bp filter. I buit for 8 ohm speakers and I have 4. So half L and double C it is. Remove some windings, retune and shunt 40uF across the existing 40uF.
ps. I am using PC and appreciate your ascii drawing skills! Your written description was enough for me but the drawing helped confirm that.
Listening to Fleetwood Mac 2002 remastered flacs. Seems there is a lot of compression used vs old recordings. Hate to be my neighbors right now!
"Another thing: "Much better now. Mids sounds great.""
The mids weren't happy being sealed in a small box! Venting with all of 4-5mm tube was just enough if I pushed the cone in, it would return (relax). Prior the speaker cone could not move much at all. May be I fluked something (there is first time for everything) but I think it just allows more cone movement.
Nothing serious, just experimental!
My friend has some really nice big speakers (6" high and must be 180L volume or something). He insisted on base reflex holes for extra bass but I tried to insist not to. He used some nasty technics 3-way crossovers. I am building some nice 12dB / octave ones with air-cored inductors for him. They will sound much better and "flat" without the reflex hole.
My speakers are just experimental. Nothing flash. They do sound good to me now. the goal was to "upgrade" with budget of $0. So far I am pretty much there! DIY is a good way to learn. I revised up on math too. I have generated all the math to verify I am on the mark.
Equals 500Hz for low pass... 😎 Tried to use scientific (engineering) notation to 3dp. I have also calculated the hp filter (5KHz) I must sit down and calculate the bp filter. I buit for 8 ohm speakers and I have 4. So half L and double C it is. Remove some windings, retune and shunt 40uF across the existing 40uF.
ps. I am using PC and appreciate your ascii drawing skills! Your written description was enough for me but the drawing helped confirm that.
Listening to Fleetwood Mac 2002 remastered flacs. Seems there is a lot of compression used vs old recordings. Hate to be my neighbors right now!
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