>>> Which is worse, a tweeter straining to go low or a whizzer cone woofer trying to go high? In this case I made my choice, seems a tweeter under stress would be the more harsh and annoying possibility... I also considered the Eminence Beta without the whizzer with a horn driver and waveguide but the costs started to mount up...
I think you did the smart thing as far as sound and cost are concerned. I wondered about similar things and usually come to the same conclusion. Not having heard the 12" Eminence, i wonder if you could have blended the tweeter in even later, say closer to 7khz or even 9khz - it probably sounds similar anyway and can be tuned to taste if someone else wants to build a pair.
>>> if you'd like i have pictures of other BIB's we've built including the 6" and 8"
I would like to see them. Please send your pics whenever you get a chance to godzilla3@hotmail.com
Many thanks. Very cool project you have there!
Godzilla
I think you did the smart thing as far as sound and cost are concerned. I wondered about similar things and usually come to the same conclusion. Not having heard the 12" Eminence, i wonder if you could have blended the tweeter in even later, say closer to 7khz or even 9khz - it probably sounds similar anyway and can be tuned to taste if someone else wants to build a pair.
>>> if you'd like i have pictures of other BIB's we've built including the 6" and 8"
I would like to see them. Please send your pics whenever you get a chance to godzilla3@hotmail.com
Many thanks. Very cool project you have there!
Godzilla
OK, here is the Eminence Beta12LTA response curve again:
http://www.partsexpress.com/pdf/290-409s.pdf
One reason I chose this driver is that it has a reputation of sounding very good.. But the final bump is supposed to be pretty ear piercing ..
I am no speaker designer by any means, but my analysis is that if you ignore the dips, it is just a rising rate starting at about 800 hz. So I put in an inductor of about 1.2 mH I believe to flatten it out. My thought was that maybe the problem is simply that the midrange is emphasized too much. The other thing that I noticed was that if I was willing to accept the upper response, the woofer just drops off like a cliff afterwards at about 6k- even steeper with the inductor in there! Since I had really good luck on my previous PA speakers having no low pass on the woofer, I decided to try it again..
Now that I sat down to write this I realize I actually did! 5k was just the lowest I wanted to go if necessary
I needed to cross the tweeter in and since the woofer was pretty flat until it drops off, and I didn't want to stress the tweeter, I used second order high pass filter at 7k
The cap was 1.8 uF I believe and maybe N-Brock will fill me in on the inductor value - he has my only sketch! Oh yeah, there is an adjustable L-pad on the tweeter tooo.
Hey N-Brock, maybe you could make a pretty version of my sketch!
I haven't heard the speakers yet but apparently there are resonances that make the box walls flap a bit, so some more bracing is in order. I suspected that would be necessary...
The other report is that they image like crazy! Now that's nice!!!
Probably it could sound a lot better by fussing with the values of the tweeter filter, but it sounds like a success so far..
Mark
http://www.partsexpress.com/pdf/290-409s.pdf
One reason I chose this driver is that it has a reputation of sounding very good.. But the final bump is supposed to be pretty ear piercing ..
I am no speaker designer by any means, but my analysis is that if you ignore the dips, it is just a rising rate starting at about 800 hz. So I put in an inductor of about 1.2 mH I believe to flatten it out. My thought was that maybe the problem is simply that the midrange is emphasized too much. The other thing that I noticed was that if I was willing to accept the upper response, the woofer just drops off like a cliff afterwards at about 6k- even steeper with the inductor in there! Since I had really good luck on my previous PA speakers having no low pass on the woofer, I decided to try it again..
Now that I sat down to write this I realize I actually did! 5k was just the lowest I wanted to go if necessary
I needed to cross the tweeter in and since the woofer was pretty flat until it drops off, and I didn't want to stress the tweeter, I used second order high pass filter at 7k
The cap was 1.8 uF I believe and maybe N-Brock will fill me in on the inductor value - he has my only sketch! Oh yeah, there is an adjustable L-pad on the tweeter tooo.
Hey N-Brock, maybe you could make a pretty version of my sketch!
I haven't heard the speakers yet but apparently there are resonances that make the box walls flap a bit, so some more bracing is in order. I suspected that would be necessary...
The other report is that they image like crazy! Now that's nice!!!
Probably it could sound a lot better by fussing with the values of the tweeter filter, but it sounds like a success so far..
Mark
working on this, haven't really gotten a chance yetGodzilla said:
Variac said:
true i have the only sketch the inductor value is a bit unclear however, it is either 1.6 or 1.3
that, and i made the sketch all nice looking
(note that the L-Pad is left out of this diagram)
EDIT: The Inductor L1 on the woofer/widerange is 1.2 uF
Good work, guys!
That simple crossover simulates very well - you may have hit the nail on the head. Looks like the acoustic x-over points falls at about 4.5KHz. L-Pad might be at around 4dB attenuation for best blend.
I'm surpised that extra bracing is needed. Would have thought that internal baffle would be enough.
FWIW, closet rod works well for bracing.
That simple crossover simulates very well - you may have hit the nail on the head. Looks like the acoustic x-over points falls at about 4.5KHz. L-Pad might be at around 4dB attenuation for best blend.
I'm surpised that extra bracing is needed. Would have thought that internal baffle would be enough.
FWIW, closet rod works well for bracing.
!0" Eminence Coax
how does this look?
Would someone sim this please, I lack the expertise to.
Thinking of using the Eminence APT-50 supertweeter, or possibly the Selenium D210 Ti.
here's the info obtained from the " BIB Calculator "
Eminence 10CX
Fs 49
Vas 2.3
Qts 0.39
Line length 137.393
Folded Height 68.697
Vb 14.177
Sm 356.613
Depth(internal) 22.457
Width(internal) 15.880
Z driver 29.814
ABC 11.229
Would probably pad the top of the low freq. driver with the crossover, and put an L pad on the tweeter, to match levels. XO at about 5K?
BTW this would be for HT use, anyone want to hazard a guess how low it will go? ( do you think I would still need a sub? )
This is a mental excercise at this point only, but I think I can slip this past the " approval committee " ( that's WAF to those who know ). Especially if I can " tart it up" to look vaguely " Mission Style" to match other furnishings.
John
how does this look?
Would someone sim this please, I lack the expertise to.
Thinking of using the Eminence APT-50 supertweeter, or possibly the Selenium D210 Ti.
here's the info obtained from the " BIB Calculator "
Eminence 10CX
Fs 49
Vas 2.3
Qts 0.39
Line length 137.393
Folded Height 68.697
Vb 14.177
Sm 356.613
Depth(internal) 22.457
Width(internal) 15.880
Z driver 29.814
ABC 11.229
Would probably pad the top of the low freq. driver with the crossover, and put an L pad on the tweeter, to match levels. XO at about 5K?
BTW this would be for HT use, anyone want to hazard a guess how low it will go? ( do you think I would still need a sub? )
This is a mental excercise at this point only, but I think I can slip this past the " approval committee " ( that's WAF to those who know ). Especially if I can " tart it up" to look vaguely " Mission Style" to match other furnishings.
John
well I'm back haha, seems like my pea brained idea took off. After reading this thread over again I'm really excited now. Can anyone give me a rough estimate in materials cost? (ply, x over, wiring, drivers ).
As money has been my only problem but after spending almost 1k on my comp I'm ready to get back on the horse and finally build what i came here for so long ago.
As money has been my only problem but after spending almost 1k on my comp I'm ready to get back on the horse and finally build what i came here for so long ago.
I thought it was my pea brained idea.. at least using the BIB design.
You wanted loud bass with big impressive drivers for less and less money. Finally this was the only way to get good bass for your budget. Not a lot of huge drivers but it is loud and bassy!!
The only way to build this at a reasonable price is to use OSB (oriented strand board) In 3/4" it costs about $15 a sheet and willl work fine. You need 5 sheets.
The guy that I know who made this is now adding more bracing because it is too flexible at the moment.
The woofers are about $70 ea. the tweeters about $30 ea.
It will still cost a little under $400. but that isn't dirt cheap I'm, afraid..
You should probably wait until I get a chance to listen to this latest one, and finalize the crossover and bracing.
You wanted loud bass with big impressive drivers for less and less money. Finally this was the only way to get good bass for your budget. Not a lot of huge drivers but it is loud and bassy!!
The only way to build this at a reasonable price is to use OSB (oriented strand board) In 3/4" it costs about $15 a sheet and willl work fine. You need 5 sheets.
The guy that I know who made this is now adding more bracing because it is too flexible at the moment.
The woofers are about $70 ea. the tweeters about $30 ea.
It will still cost a little under $400. but that isn't dirt cheap I'm, afraid..
You should probably wait until I get a chance to listen to this latest one, and finalize the crossover and bracing.
Punkr,
you really should try these
http://www.diyaudio.com/forums/showthread.php?s=&threadid=110703
You can make a PAIR for under $150 and they sound great - also loud with plenty of bass. Not as loud as PA based speakers of course, but they are a screaming bargain. And a good way to practice before risking a lot of money.. Later I'm SURE you could sell them to a friend for your investment if you want to do the BBBIBs
2 weeks ago 9 friends and I made 10 pairs and their sons are very pleased with them! As is my son!
you really should try these
http://www.diyaudio.com/forums/showthread.php?s=&threadid=110703
You can make a PAIR for under $150 and they sound great - also loud with plenty of bass. Not as loud as PA based speakers of course, but they are a screaming bargain. And a good way to practice before risking a lot of money.. Later I'm SURE you could sell them to a friend for your investment if you want to do the BBBIBs
2 weeks ago 9 friends and I made 10 pairs and their sons are very pleased with them! As is my son!
Re: !0" Eminence Coax
I posted a functionally identical one on the BIB thread: http://www.diyaudio.com/forums/showthread.php?postid=1572623#post1572623
GM
mightym said:
I posted a functionally identical one on the BIB thread: http://www.diyaudio.com/forums/showthread.php?postid=1572623#post1572623
GM
well variac i can deal with $400, it would be easy just to do sensitive dual 15" in a ported box but where's the fun in that? 
These look like the ticket. Looks like my dual 12" cabinets are about to get a bigger brother-in-law. Now I just gotta get a hold of a table saw. OSb is cheap but I wanna build something that'll hold up.I'm still thinking either oak or birch. Wouldn't a Black stained birch finish look nice?
I like EEKatSU's description ".. these things dominate!"
These look like the ticket. Looks like my dual 12" cabinets are about to get a bigger brother-in-law. Now I just gotta get a hold of a table saw. OSb is cheap but I wanna build something that'll hold up.I'm still thinking either oak or birch. Wouldn't a Black stained birch finish look nice?
I like EEKatSU's description ".. these things dominate!"
I built them a few years ago, they were monsters, both in size and output. The drivers eventually got stripped out and into a different project and the cabinets went the the trash man. As far as I know I'm the only one who has actually built these things but its been a few years since I've even thought about them. If I had the room, I'd have another pair though.
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