Btw in the pic below the yellow line is sealed .6cf
also: all with two drivers per box
also: all with two drivers per box
Attachments
Last edited:
I was looking for something better than I came up with. This all started long ago when I put one woofer in a 2cf box, 3" port, 8" long (don't really remember) the bass was shaking the whole house.....but they would bottom out.
The Iso really helped that issue, now they work effortlessly and the bass is quite amazing; sounds like I have an orchestra pit in my living room.
The speakers are crossed over at the processor, typ. 80hz.
I guess the best answer is low bass. It really would be amazing if there is a better design...........
The Iso really helped that issue, now they work effortlessly and the bass is quite amazing; sounds like I have an orchestra pit in my living room.
The speakers are crossed over at the processor, typ. 80hz.
I guess the best answer is low bass. It really would be amazing if there is a better design...........
A .6cf cab would need to be 19"T, 9"W, 6.1"D Inside
Considering: the size of the woofers, stacked one on top of the other.
Considering: the size of the woofers, stacked one on top of the other.
I found one of the "old" single woofer boxes:
OD: 12.5" w x 14.5"d x 23.5t = 1.82cf
Port was 3" x 8.5" (tuned to 30hz)
It did make pictures on the wall shake a bit in the other room. I'm sure the curve was off-the-page, bottom heavy.
Maybe I'll make a .6 cf box this weekend........need something to build.
The part I don't understand, if this is such a hard woofer to work with, why are they still making them, must be 10 years by now.
OD: 12.5" w x 14.5"d x 23.5t = 1.82cf
Port was 3" x 8.5" (tuned to 30hz)
It did make pictures on the wall shake a bit in the other room. I'm sure the curve was off-the-page, bottom heavy.
Maybe I'll make a .6 cf box this weekend........need something to build.
The part I don't understand, if this is such a hard woofer to work with, why are they still making them, must be 10 years by now.
it's not really a hard woofer to work with if you are using it as a woofer vs a subwoofer. It's very easy to design this from ~40hz up to 300Hz, but that 20-40hz octave is just below what you can really get out of them except in the near-field. Actually if those drivers could handle 250w/rms it could be a good subwoofer.
You know those little home theater in a box "boom" subs (i call them fart boxes) these are just like the drivers they use for that. so they may be OEM for some company like sony.
You know those little home theater in a box "boom" subs (i call them fart boxes) these are just like the drivers they use for that. so they may be OEM for some company like sony.
I guess I knew that, however the ad talks about muti use and long throw. The thing is massive, to look at, hold.
Thanks for the links guys, I could try the 2 in the .6cf box and/or Silly's design with the 10L and PR (now that's a tight fit).
The woofers stand 9.5" inches tall bolted face to face, and R = 3, that's .16cf (268 square inches).
If I go with the .6cf sealed do you think I should jump up to .76cf - .8cf?
Thanks for the links guys, I could try the 2 in the .6cf box and/or Silly's design with the 10L and PR (now that's a tight fit).
The woofers stand 9.5" inches tall bolted face to face, and R = 3, that's .16cf (268 square inches).
If I go with the .6cf sealed do you think I should jump up to .76cf - .8cf?
.65cf with two drivers gives a Qtc of .505. That's about as low as I would go.
I'm learning Hornresp OD design right now... if i loose it and end up in pajamas talking to trees, don't send help
I'm learning Hornresp OD design right now... if i loose it and end up in pajamas talking to trees, don't send help
Hi, and a sub amp with a built in bass boost option is probably a good idea, rgds, sreten.
I have a bigger box that I never used- 1" MDF, I think I'll saw it up and re-use it (MDF is good that way). The woofers fit the holes fine.
OD 1" MDF 11.75"w x 21"t x 8.1"d = .65cf
OD 1" MDF 11.75"w x 21"t x 8.1"d = .65cf
Attachments
Last edited:
Post #46
Hi revboden,
I doesn't look like it would like the T-TQWP, but it would work in a TH just fine. Think TH-SPUD cross-sections divided by 2 to go to single driver Sd, and divided by 2 again for the isobaric driver combination (additionally you can reduce the cross-section even more to reduce the response peaks). That'll get you from 280 L_net to 140 to 70. The throat becomes a tad skinny, but should be possible.
Regards,
Hi revboden,
I doesn't look like it would like the T-TQWP, but it would work in a TH just fine. Think TH-SPUD cross-sections divided by 2 to go to single driver Sd, and divided by 2 again for the isobaric driver combination (additionally you can reduce the cross-section even more to reduce the response peaks). That'll get you from 280 L_net to 140 to 70. The throat becomes a tad skinny, but should be possible.
Regards,
I'd be glad to experiment with a new design, material/woofers on the bench; would put pics and info up on DIY.
I would like to go back for a minute, back to the original post. I put the SA240-B in one of the boxes (3/4" MDF)...wow! I should have spent the $99 bucks and bought one of them long ago. When I moved the sub to a towel, it almost sucked it in (pic 3).
The source is a Hip Hop HD digtal radio station and I did take a few video clips.
I took the die cast woofer and put that in a un-powered Iso box, and checked the tuning for the heck of it; using a stack of resistors, volt meter, generator.
The 2 peaks are even, at 20hz and 40hz (other pics), the valley is dead on 30hz. I know ~ probably just got lucky, however the bass is near deafening.
The box is just sitting on a bench, middle of the room. Also note, the 4ohm woofers are wired in series 8ohm total.
I did a sweep test, no mic, but what I could tell:
> There's a slight ripple (or peak) around 55hz
> Somewhat smooth overall
> 30hz - 32hz it gets going pretty good, everything starts shaking.
> 25hz, some bass if you walk around the room.
The weight of the speaker with amp is 60lbs.
I would like to go back for a minute, back to the original post. I put the SA240-B in one of the boxes (3/4" MDF)...wow! I should have spent the $99 bucks and bought one of them long ago. When I moved the sub to a towel, it almost sucked it in (pic 3).
The source is a Hip Hop HD digtal radio station and I did take a few video clips.
I took the die cast woofer and put that in a un-powered Iso box, and checked the tuning for the heck of it; using a stack of resistors, volt meter, generator.
The 2 peaks are even, at 20hz and 40hz (other pics), the valley is dead on 30hz. I know ~ probably just got lucky, however the bass is near deafening.
The box is just sitting on a bench, middle of the room. Also note, the 4ohm woofers are wired in series 8ohm total.
I did a sweep test, no mic, but what I could tell:
> There's a slight ripple (or peak) around 55hz
> Somewhat smooth overall
> 30hz - 32hz it gets going pretty good, everything starts shaking.
> 25hz, some bass if you walk around the room.
The weight of the speaker with amp is 60lbs.
Attachments
Last edited:
I wonder if they would work in a T-TQWP... where's bjorno when you need him..
Hi revboden,
Using Soundhead's measured T/S for the the MCM:s in a MJK DBR simulating program:
PS. Note the odd placement of the damping material needed for best taming a bunch of these drivers in a quarter-wave design (IB).
b🙂
Attachments
Internet Kook or Genius???
That's a good nick AndyAudio, welcome to DIY!
Alas, I fear that some may think I'm a internet kook; and my design is a flop. I'm passing this box over to a friend, I bet he falls over when he hears it.
I see some ideas developing; a double chamber box looks very promising.
Cheers.
That's a good nick AndyAudio, welcome to DIY!
Alas, I fear that some may think I'm a internet kook; and my design is a flop. I'm passing this box over to a friend, I bet he falls over when he hears it.
I see some ideas developing; a double chamber box looks very promising.
Cheers.
- Status
- Not open for further replies.