Hey all.
Anybody have any ideas on how to use these for HT purposes? I'm already building two 10" dipole woofers, but these were so cheap i thought I could pick up a few for HT duty. Something to cover the sub 40Hz region.
Maybe do something fun like a pair of 4-driver sealed towers?
Any fun ideas out there? Do you guys think these would be capable of doing HT sub duty?
here are the specs:
link
Qts : .375
Qes : 0.49
Qms : 1.506
Fs : 25 Hz
Re : 1.8
Vas : 157 L
MMS : 90g
BL : 7.2 Tm
SPL : 89.1 dB
SD : 510 M^2
Xmax : 9.1 MM
Anybody have any ideas on how to use these for HT purposes? I'm already building two 10" dipole woofers, but these were so cheap i thought I could pick up a few for HT duty. Something to cover the sub 40Hz region.
Maybe do something fun like a pair of 4-driver sealed towers?
Any fun ideas out there? Do you guys think these would be capable of doing HT sub duty?
here are the specs:
link
Qts : .375
Qes : 0.49
Qms : 1.506
Fs : 25 Hz
Re : 1.8
Vas : 157 L
MMS : 90g
BL : 7.2 Tm
SPL : 89.1 dB
SD : 510 M^2
Xmax : 9.1 MM
Ths company sponsored site has the specifics
http://www.icixsound.com/vb/showthread.php?t=39744
Just noticed they are on closeout..$13.50 ea .
Get some more , I am .
http://www.icixsound.com/vb/showthread.php?t=39744
Just noticed they are on closeout..$13.50 ea .
Get some more , I am .
well, my housemate convinced me to pull the trigger. Now I have 8 of these coming my way.
You guys have any suggestions on what to do with 8 of these? I'm thinking the two towers approach, but i have no idea how to design the enclosures.
Also, any suggestion on what amp to run (going to put a plate amp in each tower)?
You guys have any suggestions on what to do with 8 of these? I'm thinking the two towers approach, but i have no idea how to design the enclosures.
Also, any suggestion on what amp to run (going to put a plate amp in each tower)?
On the company site , you will find enthusiastic help .
browse or search for EHQS12 .
There are single driver, double and quad designs posted .
there are car audio ( 12v) , and home audio forums .
http://www.icixsound.com/vb/forumdisplay.php?f=22
roughly a 2.5 cu ft box , 4in dia port by 18in long for a single
driver box , good for about 100w .
for an eye opener , look up "dodecasub" .
R U scathontipat ?
browse or search for EHQS12 .
There are single driver, double and quad designs posted .
there are car audio ( 12v) , and home audio forums .
http://www.icixsound.com/vb/forumdisplay.php?f=22
roughly a 2.5 cu ft box , 4in dia port by 18in long for a single
driver box , good for about 100w .
for an eye opener , look up "dodecasub" .
R U scathontipat ?
santiu said:
Greets!
Two 'clamshell' isobaric pairs in two BIB style pipe horns per http://www.zillaspeak.com/bib-howtobuild.asp:
L = 168.31"
Sm = 10.87" W x 15.37"D
zdriver = 36.52" (midpoint between the two pairs)
a-b-c = 7.685"
All dims i.d. and approximate.
An amp with enough power to get the job done with adjustable phase and either no boost or at least selectable to little/none.
GM
thanks for suggestions guys,
isobarically loading these seems like a good idea. I'm not too worried about volume, but weight is sort of a concern. I designed a 4 woofer ported box of around 13.5 cu ft and I'm estimating it weighs ~205 which seemed unwieldy. Had to switch gears and decided to do eight separate ported cubes that could be stacked however we wanted to stack them. I guess if i isobarically loaded them the box would be smaller, and maybe a bit lighter, maybe I could do 4 cubes with an isobaric pair in each.
How do I do the calculations for an isobarically loaded sub in a simple ported enclosure?
GM, The BiB idea also looks intriguing since it's unique. I'm not sure how I mount the woofers to the box though with the internal width of 10.87". I think the cutout diameter for these woofers is 11"
I've never built a horn. I have no idea how they sound. I think if i were to go in that direction I'd build 4 of them each with an isobarically loaded pair (since i'm splitting this with my house mate, 4's of things work out well since when we part ways we will both have a symmetric pair). Although I guess I could just do a pair with 4 drivers each. How do you arrange the drivers on the baffle? I imagine they'd still be pretty heavy, but for something as cool as that i might be able to live with it if they can outperform a big ported box. Couple questions on that... Can you isobarically load the speakers facing the same direction? I don't like looking at the backs of speakers.
Can those horns effectively play in the rumbling sound effects range? Is my ceiling going to take a beating with the horn facing up like that?
Amp wise I have a QSC USA900 to power whatever gets built (no phase adjust, no boost).
thanks again for any help!
isobarically loading these seems like a good idea. I'm not too worried about volume, but weight is sort of a concern. I designed a 4 woofer ported box of around 13.5 cu ft and I'm estimating it weighs ~205 which seemed unwieldy. Had to switch gears and decided to do eight separate ported cubes that could be stacked however we wanted to stack them. I guess if i isobarically loaded them the box would be smaller, and maybe a bit lighter, maybe I could do 4 cubes with an isobaric pair in each.
How do I do the calculations for an isobarically loaded sub in a simple ported enclosure?
GM, The BiB idea also looks intriguing since it's unique. I'm not sure how I mount the woofers to the box though with the internal width of 10.87". I think the cutout diameter for these woofers is 11"
I've never built a horn. I have no idea how they sound. I think if i were to go in that direction I'd build 4 of them each with an isobarically loaded pair (since i'm splitting this with my house mate, 4's of things work out well since when we part ways we will both have a symmetric pair). Although I guess I could just do a pair with 4 drivers each. How do you arrange the drivers on the baffle? I imagine they'd still be pretty heavy, but for something as cool as that i might be able to live with it if they can outperform a big ported box. Couple questions on that... Can you isobarically load the speakers facing the same direction? I don't like looking at the backs of speakers.
Can those horns effectively play in the rumbling sound effects range? Is my ceiling going to take a beating with the horn facing up like that?
Amp wise I have a QSC USA900 to power whatever gets built (no phase adjust, no boost).
thanks again for any help!
GM,
okay i missed your "midpoint between the two pairs" the first time i read your post. I get it now. And i guess if i mounted the woofers on some thicker baffles, they should neck down enough to fit into the throat of the horn.
What are your thoughts on making 4 horns with a pair of isobarically loaded drivers versus 2 horns with 2 pairs of drivers? Any disadvantages aside from materials and more space? Would I have to change the dimensions you provided at all?
How much if any bracing do such enclosures need?
The horn is definitely starting to sound really interesting to me. Where can i find more info on them? Maybe some of the formulas?
okay i missed your "midpoint between the two pairs" the first time i read your post. I get it now. And i guess if i mounted the woofers on some thicker baffles, they should neck down enough to fit into the throat of the horn.
What are your thoughts on making 4 horns with a pair of isobarically loaded drivers versus 2 horns with 2 pairs of drivers? Any disadvantages aside from materials and more space? Would I have to change the dimensions you provided at all?
How much if any bracing do such enclosures need?
The horn is definitely starting to sound really interesting to me. Where can i find more info on them? Maybe some of the formulas?
Greets!
You're welcome!
Assuming the program doesn't do isobaric sims, then for two drivers, change Vas, Pe, Xmax:
Vas/2
Pe*2
Xmax*2
Well, the sides have more space and since these would be strictly subs the drivers could be shifted down some. Anyway, for only two they will be plenty big enough:
L = 168.31"
Sm = 15.37" W x 21.74"D
zdriver = 36.52"
a-b-c = 10.87"
It's a very natural, effortless, room filling presentation. They are typically 6 - 10 dB more efficient than a ported box depending on the driver and room loading (ideally they should be corner loaded to extend its flare), but don't have time right now to do a sim.
'Rumble'? What do you think with all that extra efficiency?
No-one's complained about busting up their ceiling yet other than me with a pair of ServoDrive Contrabass sub kits, but I suppose there's always a first time.......
GM
You're welcome!
Assuming the program doesn't do isobaric sims, then for two drivers, change Vas, Pe, Xmax:
Vas/2
Pe*2
Xmax*2
Well, the sides have more space and since these would be strictly subs the drivers could be shifted down some. Anyway, for only two they will be plenty big enough:
L = 168.31"
Sm = 15.37" W x 21.74"D
zdriver = 36.52"
a-b-c = 10.87"
It's a very natural, effortless, room filling presentation. They are typically 6 - 10 dB more efficient than a ported box depending on the driver and room loading (ideally they should be corner loaded to extend its flare), but don't have time right now to do a sim.
'Rumble'? What do you think with all that extra efficiency?
No-one's complained about busting up their ceiling yet other than me with a pair of ServoDrive Contrabass sub kits, but I suppose there's always a first time.......GM
Oops, missed a Q....... You can mount a driver behind the baffle mounted one in its own tightly sealed mini-cab, but not in a simple pipe horn like the BIB.
Four iso horns Vs two = +3 dB, so this alone is enough to justify the extra $$/effort IMO if the budget isn't too tight.
Not a lot, a few hardwood closet rod dowels is usually sufficient when 19 mm Baltic Birch or Appleply plywood is used or vertical risers if 3/4" MDF is used.
The formulas with example is on the build page I previously referenced and there's a thread with a few thousand posts you can browse with every aspect of their design debated/critiqued to a fare-thee-well: http://www.diyaudio.com/forums/showthread.php?s=&threadid=66173
GM
Four iso horns Vs two = +3 dB, so this alone is enough to justify the extra $$/effort IMO if the budget isn't too tight.
Not a lot, a few hardwood closet rod dowels is usually sufficient when 19 mm Baltic Birch or Appleply plywood is used or vertical risers if 3/4" MDF is used.
The formulas with example is on the build page I previously referenced and there's a thread with a few thousand posts you can browse with every aspect of their design debated/critiqued to a fare-thee-well: http://www.diyaudio.com/forums/showthread.php?s=&threadid=66173
GM
Okay, I think i'm sold on trying out some horns.
Lemme see if I got this straight though. Attached are two sketches, approximately to scale. I'm looking at them as my two options- option 1: make 4 of the 2 driver enclosure; option 2: make 2 of the 4 driver enclosure. I'd still rather not do clamshells, so i was hoping to load the drivers as shown. Does that work, or am i stuck doing clamshells?
I have to mount the drivers pretty far down to fit them in. Is that okay?
Lemme see if I got this straight though. Attached are two sketches, approximately to scale. I'm looking at them as my two options- option 1: make 4 of the 2 driver enclosure; option 2: make 2 of the 4 driver enclosure. I'd still rather not do clamshells, so i was hoping to load the drivers as shown. Does that work, or am i stuck doing clamshells?
I have to mount the drivers pretty far down to fit them in. Is that okay?
Attachments
Greets!
Yes, you can do it this way, though due to the greater air 'spring' it's not quite as efficient.
I haven't drawn it out to scale, but normally there's more driver mounting space available on its side, though as long as the acoustic center (zdriver) isn't below L*0.416 it should be fine, just understand as the cluster moves down the pipe, so goes efficiency as it smooths out over a wider BW, which you don't need AFAIK.
If MDF, brace it well, running long boards along its length like done in these tapped horns (pipe horn variant), which is another option, though not nearly as easy to design: http://www.diyaudio.com/forums/showthread.php?postid=1366329#post1366329
GM
Yes, you can do it this way, though due to the greater air 'spring' it's not quite as efficient.
I haven't drawn it out to scale, but normally there's more driver mounting space available on its side, though as long as the acoustic center (zdriver) isn't below L*0.416 it should be fine, just understand as the cluster moves down the pipe, so goes efficiency as it smooths out over a wider BW, which you don't need AFAIK.
If MDF, brace it well, running long boards along its length like done in these tapped horns (pipe horn variant), which is another option, though not nearly as easy to design: http://www.diyaudio.com/forums/showthread.php?postid=1366329#post1366329
GM
GM, thanks again for all your help. A few last questions before i start buying supplies:
1) what sort of stuffing if any would you recommend?
2) just to confirm. If I make a horn with 4 drivers (two isobarically loaded pairs), then my effective Vas should be the same as if I only had a single driver correct? this yields a Vb of ~32.5 ft^3, which gives me an Sm of ~334 in^2.
3)Do I need to augment Vb (and consequently Sm) to account for any volume consumed by bracing?
thanks again for the help! I Can't wait to get started!
1) what sort of stuffing if any would you recommend?
2) just to confirm. If I make a horn with 4 drivers (two isobarically loaded pairs), then my effective Vas should be the same as if I only had a single driver correct? this yields a Vb of ~32.5 ft^3, which gives me an Sm of ~334 in^2.
3)Do I need to augment Vb (and consequently Sm) to account for any volume consumed by bracing?
thanks again for the help! I Can't wait to get started!
Greets!
You're welcome! Looking forward to a review.
None, it's a sub, so will be XO'd low enough not to matter as long as it's rigid enough.
No, the more isobaric pairs, the smaller the cab gets. Look at my dims in post #8, it's 334/2 = 167.5"^2, though I rounded the dims up a bit.
If it takes up much Vb. I use plywood, so don't need enough bracing to audibly affect performance.
GM
You're welcome! Looking forward to a review.
None, it's a sub, so will be XO'd low enough not to matter as long as it's rigid enough.
No, the more isobaric pairs, the smaller the cab gets. Look at my dims in post #8, it's 334/2 = 167.5"^2, though I rounded the dims up a bit.
If it takes up much Vb. I use plywood, so don't need enough bracing to audibly affect performance.
GM
GM said:
I thought that was what you posted, but i thought maybe I misread it. Wow, so the more drivers I have the smaller the horn is? That's so counter intuitive to me. Is there anyway you could explain physically what's going on there? Could you explain what's going on formula wise to obtain those results?
Also, could you explain why 4 horns with a single isobaric pair each is +3db over 2 horns with dual isobaric pairs each?
sorry for all the questions
just trying to learn and figure all this stuff out. thanks again for all the help. And I'll be sure to take plenty of pictures and write about my impressions once these get built.
Greets!
Well, there's no 'free lunch', you're paying dearly for the reduced Vb in added drivers, increased distortion that severely limits usable BW and amp power required to be as loud as a single driver in a big cab.
It's my understanding that two drivers loaded isobarically doubles its moving mass/air load (Mmd) and since compliance (Cms) is inversely proportional to mass, it's cut in half and since equivalent volume is proportional to compliance, Vas is cut in half also, ergo if two isobaric pairs are coupled together its effective Vas is reduced by a factor of four referenced to one.
Now in each case they are no louder than a single unit with each driver at the same electrical power (ignoring the increased effective Xmax of multiple drivers) and since a doubling of sound power sources (decibels) is a doubling of sound pressure (SPL), i.e. four horns Vs two: 10*log10(4/2) = ~ +3 dB.
This is all just theory though, in the real world there will be losses and complex room interactions, but you have to start somewhere.
GM
Well, there's no 'free lunch', you're paying dearly for the reduced Vb in added drivers, increased distortion that severely limits usable BW and amp power required to be as loud as a single driver in a big cab.
It's my understanding that two drivers loaded isobarically doubles its moving mass/air load (Mmd) and since compliance (Cms) is inversely proportional to mass, it's cut in half and since equivalent volume is proportional to compliance, Vas is cut in half also, ergo if two isobaric pairs are coupled together its effective Vas is reduced by a factor of four referenced to one.
Now in each case they are no louder than a single unit with each driver at the same electrical power (ignoring the increased effective Xmax of multiple drivers) and since a doubling of sound power sources (decibels) is a doubling of sound pressure (SPL), i.e. four horns Vs two: 10*log10(4/2) = ~ +3 dB.
This is all just theory though, in the real world there will be losses and complex room interactions, but you have to start somewhere.
GM
AH HAH! I found why there's a disconnect. I think the formula for Sm on the BiB how-to-build page is missing a factor of 2! Boy, i thought I was going mad here. Now I'm on board with your dimensions for a single isobaric pair.
However, I think there's still a disconnect concerning using 4 drivers. I was planning on using them in parallel like this:
In this case I think that Vas is halved for each pair, and then since they are in parallel, the effective Vas is the sum of each of the pair's Vas, so you get back to ground zero: Vas/2+Vas/2=Vas.
Effective Vas = 5.54 cu ft
Vb = 20*5.54*0.375^1.25 = 32.54 ft^3
Sm = 2*32.54*1728/168 = 669 in^2
I think what you were thinking i was going to do was load 2 pairs of isobaric driver in series like this:
In that case, i agree with you that Vas would be reduced by a factor of 4.
Effective Vas = 1.386
Vb = 20*1.386*0.375^1.25 = 8.14 ft^3
Sm = 2*8.14*1728/168 = 167 in^2
OKay. i think that's cleared up now. I think...
Now, when comparing 4 horns with a single pair, versus 2 horns with 2 pairs in parallel. I don't see why there would be a difference in loudness.
Phew... hopefully i got this right that time. My head was about to explode with confusion.
However, I think there's still a disconnect concerning using 4 drivers. I was planning on using them in parallel like this:
An externally hosted image should be here but it was not working when we last tested it.
In this case I think that Vas is halved for each pair, and then since they are in parallel, the effective Vas is the sum of each of the pair's Vas, so you get back to ground zero: Vas/2+Vas/2=Vas.
Effective Vas = 5.54 cu ft
Vb = 20*5.54*0.375^1.25 = 32.54 ft^3
Sm = 2*32.54*1728/168 = 669 in^2
I think what you were thinking i was going to do was load 2 pairs of isobaric driver in series like this:
An externally hosted image should be here but it was not working when we last tested it.
In that case, i agree with you that Vas would be reduced by a factor of 4.
Effective Vas = 1.386
Vb = 20*1.386*0.375^1.25 = 8.14 ft^3
Sm = 2*8.14*1728/168 = 167 in^2
OKay. i think that's cleared up now. I think...
Now, when comparing 4 horns with a single pair, versus 2 horns with 2 pairs in parallel. I don't see why there would be a difference in loudness.
Phew... hopefully i got this right that time. My head was about to explode with confusion.
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