Banned
Joined 2002
I've got 4 4ohm 12's per channel, series parallel, in sealed boxes with a Q of .5. Just a touch of EQ from my custom crossover brings the Q up to .7 and extends the lows a tad. Flat down to about 20 Hz or so. Very efficient and the cones barely move even at high volume. Very clean and tight.
They are oem drivers made for a company called Edge. Very tasty woofers - nice specs and high build quality. I was offered a good price on them at $25 per so I took the last dozen from a discontinued project.
As to configuration see:
http://www.kbacoustics.com/ygbsm/mysystem/index.html
Note that the page says a Qtc of .65 for the enclosed system. I have since changed that to .5. I guess it's time to update the site soon since I intend to change the midrange system to a vertical curved array.
I may change the bass layout as well. I own my own home, am not interested in resale value and am a very good woodworker so I can do as I damn well please. I'm aiming for audio NIrvana. Although I like most music I favor metal and look for front row center at concert levels. Don't mistake this comment for shallowness or crude power desires; very high resolution remains an important factor. I'll get this puppy to lauch a square wave if it kills me.
Things are progressing as I have foreseen.
As to configuration see:
http://www.kbacoustics.com/ygbsm/mysystem/index.html
Note that the page says a Qtc of .65 for the enclosed system. I have since changed that to .5. I guess it's time to update the site soon since I intend to change the midrange system to a vertical curved array.
I may change the bass layout as well. I own my own home, am not interested in resale value and am a very good woodworker so I can do as I damn well please. I'm aiming for audio NIrvana. Although I like most music I favor metal and look for front row center at concert levels. Don't mistake this comment for shallowness or crude power desires; very high resolution remains an important factor. I'll get this puppy to lauch a square wave if it kills me.
Things are progressing as I have foreseen.
Hi Bill,
It sounds like you got a good deal on the woofers. You might have to go digital xovers and time delays to get that square wave your looking for.
So you have a crawl space. Here's a good crawl space project for you.
http://www.royaldevice.com/custom3.htm
You'd like my son's music collection
Rodd Yamas***a
It sounds like you got a good deal on the woofers. You might have to go digital xovers and time delays to get that square wave your looking for.
So you have a crawl space. Here's a good crawl space project for you.
http://www.royaldevice.com/custom3.htm
That's funny, I never figured you for the mosh pit type.
You'd like my son's music collection
Rodd Yamas***a
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Banned
Joined 2002
That's right, it's the grunge groups that have the mosh pits. Sorry Bill.
Square wave. The fundamental frequency plus all odd order harmonics. Now this you can reproduce. What I can't see is how to reproduce the harmonics with their original phase relationship to the fundamental frequency with a multi-way system.
If you go active xovers to eliminate the the passive xovers, you still have the frequency dependent phase shift.
If you run bandpass boxes with no xovers, you still have frequency dependent phase shifts associated with the inductive and capacitive components of a speaker in a box.
It doesn't make sense to make a multiway system with full range drivers. That might get you close in the speakers bandpass, but the system wouldn't sound very good.
There is no reasonable way to eliminate the frequency dependent phase shifts of analog circuits.
The only way that I can think of is digital FIR filters and digital time delays to contend with variations in the acoustic centers of the drivers. Even then, I fear that the best you'll get is a rough approximation of the original square wave, but if this could result in a phase coherent reproduction of the leading edge of the square wave, I would be very happy with that.
ok? Did I miss anything?
Rodd Yamas***a
1. why do you want to got o 20Hz. Do you the room problems you will have to slove to really have clean bass at 20Hz?
2. If you are going that low I would suggest multiple 12" drivers.
I have built a lot of subs. The biggest and baddest were using 18" JBL 2245 drivers in 8 cu. ft. bass reflex boxes (one per channel). $400 per driver total $800. The midbass for each channel was 2 Focal 8" woofers that lesser systems use for subs.
The next were a pair of sealed boxes built for corner placement using 3 12" from Audio Concpets (DV12)per box. Each 12" has 2 voice coils so I could expriment with short ing the other voice coil, etc. Again 1 sub per channel. $100 per driver total $600 sealed box 10cu. ft. f3=25Hz. Room treatment cost more.
Presently I am using 2 Audio Concpets SV12s per channel. Cost about $125 per driver total $500. Sealed box. F3=30Hz.
I have also built a 3 chamber 4th order band pass box using 2 Peerless 831727 10" woofer per box. $100 per driver total $400.
now you could ask would I choose between the 2245 or 4 Peerless woofers. For each moving of air the 2245 is superb. For bass definition the SV12 are great. The Peerless is great for thump but not otherwise.
hope this helps.
regards
navin
2. If you are going that low I would suggest multiple 12" drivers.
I have built a lot of subs. The biggest and baddest were using 18" JBL 2245 drivers in 8 cu. ft. bass reflex boxes (one per channel). $400 per driver total $800. The midbass for each channel was 2 Focal 8" woofers that lesser systems use for subs.
The next were a pair of sealed boxes built for corner placement using 3 12" from Audio Concpets (DV12)per box. Each 12" has 2 voice coils so I could expriment with short ing the other voice coil, etc. Again 1 sub per channel. $100 per driver total $600 sealed box 10cu. ft. f3=25Hz. Room treatment cost more.
Presently I am using 2 Audio Concpets SV12s per channel. Cost about $125 per driver total $500. Sealed box. F3=30Hz.
I have also built a 3 chamber 4th order band pass box using 2 Peerless 831727 10" woofer per box. $100 per driver total $400.
now you could ask would I choose between the 2245 or 4 Peerless woofers. For each moving of air the 2245 is superb. For bass definition the SV12 are great. The Peerless is great for thump but not otherwise.
hope this helps.
regards
navin
Banned
Joined 2002
that is a nice settup man i like that im doing some thing like this ( found this photo on passdiy.com and have talked to the person too.. )
But ill be putting in 2 10" per box ( lower box that is ) and haveing the port out the rear.. and ill power all the 10 with 2 n-channels that i am working on ( one is compleet post pics later on in week..)
: O )
But ill be putting in 2 10" per box ( lower box that is ) and haveing the port out the rear.. and ill power all the 10 with 2 n-channels that i am working on ( one is compleet post pics later on in week..)
: O )
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2 10" would require twice the box volume.
while bass reflex drivers do provide more punch they are also notoriously diffilcult to get right for all types of music.
I used to suffer from all sorts of probelms when i was using bass reflex systems. In the end I solved the problem by using ports of different lengths. Every album I had had a note on which lenght of port sounded best.
Most 10" drivers I know SS (the photo seems like a SS 25W8565), Focal (10K516J, 10N515, etc...) and even the el cheapo Peerless (CSX and 831727) require min. 2.5 cu. ft. There are however many 12" dirvers (Shiva, Audio Concpets) etc. that have really long Xmax (12mm or so) and work well in 3 cu. ft.
The 12" drivers I have mentioned are slower (BL/Mms) than the Focal or SS drivers for sure but if you are crossing over at 60 or 80Hz you dont need the extra speed do you?
For the money 2 12" with 12mm linear one way Xmax can move much more air than 2 10" with 9mm linear one way Xmax even if the 10" are in a ported box. What you loose is sensitivity.
If one is going active (then you dont have to worry about sensitivity either) one can even equallise bass end using a Audio Control C101 or something similar.
Bass uses prodigious ammounts of power and to keep the mid bass amp from panting going active is a good option.
acitve has a lot of advantages...
1. for 3 way systems you get away by making a 2 way passive network and using an active XO for the LF.
2. your full range amp does not have to work as hard producing power hungry bass
3. you can eq the bass without affecting the rest of the sound.
4. for acapella, acoustic and baroque music I actually do not turn my bass amp on at all! The signal thenis clean CD - simple preamp - power amp (no EQ, no processing).
the attached phot shows my home made pre amp and power amp. the boxes are from a local power supply company called Nova which I then screen printed.
the left side of the rack is the pre and power amps. the right side is fed via a regulated supply and is te CD players (63KI, Phonisophie, Marantz CD writer, Tape Deck - Pioneer CT93 and EQ for the bass)
while bass reflex drivers do provide more punch they are also notoriously diffilcult to get right for all types of music.
I used to suffer from all sorts of probelms when i was using bass reflex systems. In the end I solved the problem by using ports of different lengths. Every album I had had a note on which lenght of port sounded best.
Most 10" drivers I know SS (the photo seems like a SS 25W8565), Focal (10K516J, 10N515, etc...) and even the el cheapo Peerless (CSX and 831727) require min. 2.5 cu. ft. There are however many 12" dirvers (Shiva, Audio Concpets) etc. that have really long Xmax (12mm or so) and work well in 3 cu. ft.
The 12" drivers I have mentioned are slower (BL/Mms) than the Focal or SS drivers for sure but if you are crossing over at 60 or 80Hz you dont need the extra speed do you?
For the money 2 12" with 12mm linear one way Xmax can move much more air than 2 10" with 9mm linear one way Xmax even if the 10" are in a ported box. What you loose is sensitivity.
If one is going active (then you dont have to worry about sensitivity either) one can even equallise bass end using a Audio Control C101 or something similar.
Bass uses prodigious ammounts of power and to keep the mid bass amp from panting going active is a good option.
acitve has a lot of advantages...
1. for 3 way systems you get away by making a 2 way passive network and using an active XO for the LF.
2. your full range amp does not have to work as hard producing power hungry bass
3. you can eq the bass without affecting the rest of the sound.
4. for acapella, acoustic and baroque music I actually do not turn my bass amp on at all! The signal thenis clean CD - simple preamp - power amp (no EQ, no processing).
the attached phot shows my home made pre amp and power amp. the boxes are from a local power supply company called Nova which I then screen printed.
the left side of the rack is the pre and power amps. the right side is fed via a regulated supply and is te CD players (63KI, Phonisophie, Marantz CD writer, Tape Deck - Pioneer CT93 and EQ for the bass)
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