I decided to build a subwoofer...
I'm using 8 MCM 55-1190 8" drivers in a 12 cuft. sealed enclosure, with a Parts Express 250W sub amp. I plan on using electronic enhancement to extend the low end. This is kind of a throw-together project, but I thought someone might be interested. Let me know, and I'll post some pictures of the cabinet. It looks like a coffin (in size, at least).
It is 72-1/2" tall X 15-1/2" wide X 24" deep! Fun fun fun...
I'm using 8 MCM 55-1190 8" drivers in a 12 cuft. sealed enclosure, with a Parts Express 250W sub amp. I plan on using electronic enhancement to extend the low end. This is kind of a throw-together project, but I thought someone might be interested. Let me know, and I'll post some pictures of the cabinet. It looks like a coffin (in size, at least).
It is 72-1/2" tall X 15-1/2" wide X 24" deep! Fun fun fun...
I've got a couple shelf braces in there, and I plan to throw a few 2"X.75"pieces from panel to panel to try and stiffen things up a little...
I did all the cutting yesterday, and the panels have some bracing screwed / glued in. I plan on assembling the cabinets tonight.
Got any ideas that are cheap and easy? (for bracing, that is).
I did all the cutting yesterday, and the panels have some bracing screwed / glued in. I plan on assembling the cabinets tonight.
Got any ideas that are cheap and easy? (for bracing, that is).
accelerometer
I got some freebies from AD. They're +/-100G full range, mounted on the inside of the voice coil former near where the dust cap attaches. As soon as I figure out the $#@&ing schematic drawing software, I'll put the interface up- it's all opamp-based, fed back to the input of the Adcom. Nothing unusual or exotic, just filtering and phase adjusting.
The resulting woofer system is flat (small signal) to a little below 15 Hz.
I have a better idea on how to do this which could be cheaper, better, and more amenable to the typical DIY (less driver surgery), but I need the assistance of someone who really knows their stuff regarding microcontrollers and other digital stuff. Any potential collaborators, preferably in the Bay Area, please email me.
I got some freebies from AD. They're +/-100G full range, mounted on the inside of the voice coil former near where the dust cap attaches. As soon as I figure out the $#@&ing schematic drawing software, I'll put the interface up- it's all opamp-based, fed back to the input of the Adcom. Nothing unusual or exotic, just filtering and phase adjusting.
The resulting woofer system is flat (small signal) to a little below 15 Hz.
I have a better idea on how to do this which could be cheaper, better, and more amenable to the typical DIY (less driver surgery), but I need the assistance of someone who really knows their stuff regarding microcontrollers and other digital stuff. Any potential collaborators, preferably in the Bay Area, please email me.
OK, I took a look at it; this Note was apparently a school project. Not a particularly good implementation, as the students noted. Thanks for letting me know about it, though.
Much of my implementation was based on some articles in Speaker Builder about 10 years back. They used cruder accellerometers, so I was able to simplify their circuits a bit since the AD device was so good.
Much of my implementation was based on some articles in Speaker Builder about 10 years back. They used cruder accellerometers, so I was able to simplify their circuits a bit since the AD device was so good.
Have you seen this website?
http://home.insightbb.com/~stephenwmoore/Speakers/Active_Subwoofer/Active_Subwoofer.htm
He's basing his design on som old articles. Maybe it's the same?
/Marcus
http://home.insightbb.com/~stephenwmoore/Speakers/Active_Subwoofer/Active_Subwoofer.htm
He's basing his design on som old articles. Maybe it's the same?
/Marcus
Wow! Do they stand upright or lay on their sides like my pair of 8.652093346 cubic foot subs, also with 8 inch woofers? Pictures? Oh yeah!!nobody special said:Let me know, and I'll post some pictures of the cabinet. It looks like a coffin (in size, at least). It is 72-1/2" tall X 15-1/2" wide X 24" deep! Fun fun fun...
I would definitely be interested in your servo setup too... I've been wondering for a while how hard it would be to do.
Circlotron,
They're meant to stand up (I had to minimize floor space). I will post some pictures when they are a little more together. I am planning on final assembly in the next 2 nights (excluding finish- If they sound good I will veneer them and make some grilles).
How about some details on your system? Do you have any pictures? How does it sound?
I figure that multiple 8's will be punchy, and with an LT circuit, should beable to hit 110db at 20hz.
Circlotron,
They're meant to stand up (I had to minimize floor space). I will post some pictures when they are a little more together. I am planning on final assembly in the next 2 nights (excluding finish- If they sound good I will veneer them and make some grilles).
How about some details on your system? Do you have any pictures? How does it sound?
I figure that multiple 8's will be punchy, and with an LT circuit, should beable to hit 110db at 20hz.
Yep, there is a thread here. http://diyaudio.com/forums/showthread.php?s=&threadid=9714&highlight=245nobody special said:
Soundwise, they are not in the "deathbox" or "housewrecker" category, but they are quite capable of keeping up with a good and full listening level. sound level, it does not go as good as a megabuck system of course, but given the little money spent, and the non-startling drivers used though, it is a winner. It does *exactly* what I wanted it to. Goes as low as many (but not all) big buck systems. Gives real weight to the bottom end like in a cinema sometimes where you hear a real shaker of a note. 25 to 35 Hz is a whole new experience. Feels like when you are standing on the platform of a railway station and the train pulls in and you can feel the clunk-clunk...clunk-clunk under your feet. For anyone who hasn't got a real sub yet, you will be pleased when you do.
Nice looking subs!
I hope to experience that "train" feeling soon. I just finished up the main part of the cabinet tonight. I have to cut / route a place for the amp tomorrow, and set the drivers in. I plan to fire it up Thursday evening (want to give the glue and caulk time to set up good). Pictures below.
-NS
I hope to experience that "train" feeling soon. I just finished up the main part of the cabinet tonight. I have to cut / route a place for the amp tomorrow, and set the drivers in. I plan to fire it up Thursday evening (want to give the glue and caulk time to set up good). Pictures below.
-NS
I didn't use any bracing on mine at all and it has a big panel resonance at 126 Hz. I am rolling them off at 12 db per octave from 100Hz so it isn't too much of a problem. 12 cu ft and 8 drivers is 1.5 cu ft per driver so really yours and my subs are worlds apart except for overall size. Should be able to hear yours from my place. Actually, as far as bracing is concerned, I think the best way might be to have a length of angle iron with a sort of foot on each end and screw the feet to the inside of opposite panels. That way when they both try and flex out or in at the same time they will provide the ideal anchor for each other. They will use up their flexing force holding the other still. I see you have a couple of that kind of thing between the front and back. The only reason I didn't use this kind of brace in mine was because I was in too much of a rush. heh heh
Actually, as far as bracing is concerned, I think the best way might be to have a length of angle iron with a sort of foot on each end and screw the feet to the inside of opposite panels. That way when they both try and flex out or in at the same time they will provide the ideal anchor for each other. They will use up their flexing force holding the other still. I see you have a couple of that kind of thing between the front and back. The only reason I didn't use this kind of brace in mine was because I was in too much of a rush. heh heh- Status
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