i'm now in a position to mount my ciare ch250's to a baffle.
i have a W frame housing two 15's handling anything below 90hz or so, and was wondering what the consensus seems to be regarding the shape of open baffles for medium low response.
would mounting this driver to a 2 foot wide by 5 foot tall board be equivelant to any other configuration with 10 square feet of surface area?
i'd imagine they would respond very differently.
this in mind, i'd like to keep the width of my baffle as narrow as possible due to spade limitations in a high traffic area, and would also like to have the driver at least 3 feet from the ground.
i gotta say though, i'm very imperssed as it is with just the drivers hooked up and sitting on the boxes they came out of. and the sub of course
its hard to imagine any setup i put these drivers into would not kick ***.
i have a W frame housing two 15's handling anything below 90hz or so, and was wondering what the consensus seems to be regarding the shape of open baffles for medium low response.
would mounting this driver to a 2 foot wide by 5 foot tall board be equivelant to any other configuration with 10 square feet of surface area?
i'd imagine they would respond very differently.
this in mind, i'd like to keep the width of my baffle as narrow as possible due to spade limitations in a high traffic area, and would also like to have the driver at least 3 feet from the ground.
i gotta say though, i'm very imperssed as it is with just the drivers hooked up and sitting on the boxes they came out of. and the sub of course
its hard to imagine any setup i put these drivers into would not kick ***.
smak,
a lot of the bass you get from an OB stems from the floor reflection/assistance. With a small footprint and a driver quite high up from the floor (like you want to have it) I have my doubts whether you can expect enough bass left at 90 Hz.
What about dividing your W frame into two N frames, integrating them in the bottom of your OBs and taking them to an X-over at 120-160 Hz? Even if you power the subs still mono, they will integrate quite well.
The Ciares should work perfectly in those OBs above ~120 Hz.
Rudolf
a lot of the bass you get from an OB stems from the floor reflection/assistance. With a small footprint and a driver quite high up from the floor (like you want to have it) I have my doubts whether you can expect enough bass left at 90 Hz.
What about dividing your W frame into two N frames, integrating them in the bottom of your OBs and taking them to an X-over at 120-160 Hz? Even if you power the subs still mono, they will integrate quite well.
The Ciares should work perfectly in those OBs above ~120 Hz.
Rudolf
Member
Joined 2003
smak,
There are a lot of tradeoffs involved. In the 90 Hz range, response is heavily dependent on front/back path length so you could "fold" the baffle into a "U" shape for a smaller visual footprint. However, the parallel walls of a U can introduce audible midrange resonances. Also, the shape of the baffle influences diffraction at higher frequencies so try to avoid 90 degree turns...avoid sharp edges.
Google for "pvconsultants" and use Paul V's baffle diffraction simulator to help evaluate alternative baffle shapes. SL's site includes a calculator that will help you with LF.
The baffles shown here are "C" shaped, but I've also had good results with "V" baffles. The Vs (45 degree wings) are relatively easy to build.
Have fun!
Paul
There are a lot of tradeoffs involved. In the 90 Hz range, response is heavily dependent on front/back path length so you could "fold" the baffle into a "U" shape for a smaller visual footprint. However, the parallel walls of a U can introduce audible midrange resonances. Also, the shape of the baffle influences diffraction at higher frequencies so try to avoid 90 degree turns...avoid sharp edges.
Google for "pvconsultants" and use Paul V's baffle diffraction simulator to help evaluate alternative baffle shapes. SL's site includes a calculator that will help you with LF.
The baffles shown here are "C" shaped, but I've also had good results with "V" baffles. The Vs (45 degree wings) are relatively easy to build.
Have fun!
Paul
An externally hosted image should be here but it was not working when we last tested it.
2x5 with the driver located 3 feet off the ground was just an example.. i can easily put to use a design that is closer to an ideal OB configuration.
i think i'm going to try a 80cm tall baffle by 40cm wide.. and locate the drive at about 65cm from the ground. i'll use cheap stock to build with until i tune to a design i really like.
hope that will leave some 90hz to work with. i dont have alot of room to place the driver away from the wall which may help a bit also, but sacrafice the waves interacting like they should.
my mono w-frame dipole serves double duty as a nice table stand in between two theatre seats i use when watching dvd's. i'd like to keep it in the back of my room due to space restrictions.
thanks for the http://www.pvconsultants.com/audio/frdgroup.htm tools.. if i had a windows/dos box handy it would come in handy ;P wouldent happen to have any online cacluators handy eh? i'll hold onto that link though
will try and post pics of results when i get something nice together.
i think i'm going to try a 80cm tall baffle by 40cm wide.. and locate the drive at about 65cm from the ground. i'll use cheap stock to build with until i tune to a design i really like.
hope that will leave some 90hz to work with. i dont have alot of room to place the driver away from the wall which may help a bit also, but sacrafice the waves interacting like they should.
my mono w-frame dipole serves double duty as a nice table stand in between two theatre seats i use when watching dvd's. i'd like to keep it in the back of my room due to space restrictions.
thanks for the http://www.pvconsultants.com/audio/frdgroup.htm tools.. if i had a windows/dos box handy it would come in handy ;P wouldent happen to have any online cacluators handy eh? i'll hold onto that link though
will try and post pics of results when i get something nice together.
i was looking for a chart in the past that displayed OB size vs bass response and finally came across the link again. its pretty nifty although i dont know how accurate it is considering that it doesent take into account a drivers distance from the ground and Qts.
http://www.angelfire.com/electronic/DIY/OB-Speaker-concept-1b.html
anyways i setup my caire ch250's with a "shelving" kit i found at the local home depot. $8 a side with nicely trimmed edges. i cut them down a bit to size and ended up with about 34 inches of height by 12" width.
according to the linked chart, i shouldent be getting lower than 260Hz or so but the sound i'm getting seems nice and full so i'm a bit baffled (no pun intended) as to what to think.
i found a set of supertweeters were defianty required for high frequencies and i've got some Foster 025N47 8 Ohm's playing that duty with solen .47 caps in line. they were kinda slapped on as an afterthought but enrich the aural experience quite significantly.
quickie photo of my setup, not sure if i'm going to use completely new baffles later on or just widen these by adding glass around the perimiter.
thnx for the help sofar all.
http://www.angelfire.com/electronic/DIY/OB-Speaker-concept-1b.html
anyways i setup my caire ch250's with a "shelving" kit i found at the local home depot. $8 a side with nicely trimmed edges. i cut them down a bit to size and ended up with about 34 inches of height by 12" width.
according to the linked chart, i shouldent be getting lower than 260Hz or so but the sound i'm getting seems nice and full so i'm a bit baffled (no pun intended) as to what to think.
i found a set of supertweeters were defianty required for high frequencies and i've got some Foster 025N47 8 Ohm's playing that duty with solen .47 caps in line. they were kinda slapped on as an afterthought but enrich the aural experience quite significantly.
quickie photo of my setup, not sure if i'm going to use completely new baffles later on or just widen these by adding glass around the perimiter.
thnx for the help sofar all.
An externally hosted image should be here but it was not working when we last tested it.
Larry Selmer talked me into building non-parallel H/U frames. Not the prettiest thing to have in your living room but they work well.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
When it comes to OB size and shape, I believe the main issues are:
* fequal where the SPL is the same as the driver in a sealed box, below this point there is an extra 1st order rolloff due to cancellation
* polar response
both relate mostly to width rather than to area
you can add wings, although many comment that better sound is achieved with out wings, or small ones, although tradeoffs need to be made here
* fequal where the SPL is the same as the driver in a sealed box, below this point there is an extra 1st order rolloff due to cancellation
* polar response
both relate mostly to width rather than to area
you can add wings, although many comment that better sound is achieved with out wings, or small ones, although tradeoffs need to be made here
i dont know about adding wings to the baffle.. i really enjoy the simplicity of a flat baffle design and think it works well in the room. i'd rather add a bit of width than wings for now.
with those pyramid type speakers though, why not have the two lower woofers play in dipole as if they were in an h-frame, and then have the midrange/ribbon cover higher frequencies?
if i had a bit more room it looks like a design i'd like to give a shot.. although i'd probably get another couple pyle 15's and some ribbon tweeters to do the job right
with those pyramid type speakers though, why not have the two lower woofers play in dipole as if they were in an h-frame, and then have the midrange/ribbon cover higher frequencies?
if i had a bit more room it looks like a design i'd like to give a shot.. although i'd probably get another couple pyle 15's and some ribbon tweeters to do the job right
smak said:with those pyramid type speakers though, why not have the two lower woofers play in dipole as if they were in an h-frame, and then have the midrange/ribbon cover higher frequencies?
if i had a bit more room it looks like a design i'd like to give a shot.. although i'd probably get another couple pyle 15's and some ribbon tweeters to do the job right
Actually, the two 12" woofers are dipole and the tweeter is a NeoPro5i ribbon.
I don't think there's anything wrong with keeping the baffle narrow. A bigger baffle reduces or eliminates the need to compensate for dipole roll-off. If you use a smaller than ideal baffle, you just need to compensate with a shelving low pass filter. I guess you still need to make sure the driver can handle the increased excursion that will result.
As paulspencer points out, the Orion baffles and wings are pretty shallow. Linkwitz uses a shelving low pass filter to compensate for dipole roll-off with both the mid and the woofer.
http://linkwitzlab.com/orion_asp.htm
I assume you're going active, right?
Wow Ultrachrome! How'd I miss your setup, that's sweet!
I have a crazy question for you, have you ever tried operating that system without the PR170? With steep slopes that Neo5 should reach down to 1200-1300, I'm thinking those Lambdas would actually work quite well up that high (Similar to somthing I'm fiddling with right now AMT/Lambda TD12). The only thing might be cavity resonance from the H-frame, but with the baffles shaped like that? Anyhow, just wondering. I'm still working on dialing in a 48db/octave passive filter on that combo, but so far it sounds pretty good.
Thanks
John
I have a crazy question for you, have you ever tried operating that system without the PR170? With steep slopes that Neo5 should reach down to 1200-1300, I'm thinking those Lambdas would actually work quite well up that high (Similar to somthing I'm fiddling with right now AMT/Lambda TD12). The only thing might be cavity resonance from the H-frame, but with the baffles shaped like that? Anyhow, just wondering. I'm still working on dialing in a 48db/octave passive filter on that combo, but so far it sounds pretty good.
Thanks
John
Thanks.
I did do that once but it was unimpressive. The woofers were in a deep H-frame at the time. I didn't spend any time on it, though. I do think an MTM would be kind of funny.
When I finish working on these with SoundEasy, I'll sim a MTM with just the woofers and tweeters and see what it looks like.
I did do that once but it was unimpressive. The woofers were in a deep H-frame at the time. I didn't spend any time on it, though. I do think an MTM would be kind of funny.
When I finish working on these with SoundEasy, I'll sim a MTM with just the woofers and tweeters and see what it looks like.
Sorry for the hijack Smak.
Rudolf,
Unfortunately, I can't really tell you off the top of my head. Too much as been changing with my system.
When I get home I'll see if I saved any pink noise measurements I did with TrueRTA that can compare the two.
Last month I bought SoundEasy but have only had time to learn T/S measurements. I might have some time this Sunday and if it's dry (big if), I'll drag them outside and try to do some real measurements of both baffles.
Rudolf,
Unfortunately, I can't really tell you off the top of my head. Too much as been changing with my system.
When I get home I'll see if I saved any pink noise measurements I did with TrueRTA that can compare the two.
Last month I bought SoundEasy but have only had time to learn T/S measurements. I might have some time this Sunday and if it's dry (big if), I'll drag them outside and try to do some real measurements of both baffles.
Thank you for your effort, ultracrome.
And my apologies too, smak.
The OB size vs. bass diagram at angelfire is less than precise, as you already stated. It calculates the response of a baffle in free air.
I wonder if you have tried Kuei Yang Wangs xlbaffle.xls (download at http://www.exdreamnet.de/download/Xlbaffle.xls )
That does take into account a drivers distance from the ground, the side and back wall and some T/S parameters. So you might get a better picture where your bass comes from.
And my apologies too, smak.
The OB size vs. bass diagram at angelfire is less than precise, as you already stated. It calculates the response of a baffle in free air.
I wonder if you have tried Kuei Yang Wangs xlbaffle.xls (download at http://www.exdreamnet.de/download/Xlbaffle.xls )
That does take into account a drivers distance from the ground, the side and back wall and some T/S parameters. So you might get a better picture where your bass comes from.
no probs at all guys, i'm learning with each passing thread weather on topic or not so its all good.
thnx for that spreadsheet, its a bit "apples to oranges" to be able to guestimate any response curves for the caire bicone but it definatly underlines the shortcomings of the previous graph.
i bumped my plate amp xo up to 140Hz and am confidant that i'm not missing out on too much in the frequency range, but should eventually get some good measuring equipment to confirm.
i would eventually like to add an eq and active xo into the mix but need to curb my spending for now a bit.
p.s. ultra, if running in dipole why not invert one of the drivers like seen in conventional H-frame baffles? is there any benefit to having both cones facing the same direction other than it looks neater and less conspicuous?
thnx for that spreadsheet, its a bit "apples to oranges" to be able to guestimate any response curves for the caire bicone but it definatly underlines the shortcomings of the previous graph.
i bumped my plate amp xo up to 140Hz and am confidant that i'm not missing out on too much in the frequency range, but should eventually get some good measuring equipment to confirm.
i would eventually like to add an eq and active xo into the mix but need to curb my spending for now a bit.
p.s. ultra, if running in dipole why not invert one of the drivers like seen in conventional H-frame baffles? is there any benefit to having both cones facing the same direction other than it looks neater and less conspicuous?
I did have the woofers flipped before. My guru, Larry Selmer mentioned that because my woofers were designed for dipole use (Lambda Dipole12's built by John @ AcousticElegance), mounting this way was unnecessary.
That said, when in the H-frame I remember my pink noise measurements were slightly smoother with the 180 woofers but I believe it was well above my crossover point.
That said, when in the H-frame I remember my pink noise measurements were slightly smoother with the 180 woofers but I believe it was well above my crossover point.
Actually, I have a question for you. Why crossover so low? If you raise your crossover point, the effect of an undersized baffle diminishes. Plate amp limitation?
As far as EQ and X-over are concerned. A single DCX2496 can fulfill both functions as far as dipole effects are concerned. If you want EQ for room issues, then I guess you'll have to add something like a DEQ2496.
I'm only using a DCX and set everything up with pink noise using a Behringer ECM8000 mic ($50), M-audio preamp ($50), and TrueRTA ($70-100). You can get things sounding pretty good that way which is really nice when they're dominating your living room while you figure out how to do it the right way.
In my situation, I'm running a low pass on my woofers at their Fs, 26Hz. This flattens the woofer response but requires you to boost the woofer level and/or lower the mid/tweet level to match. My mid is high-passed at 300Hz although the baffle width pretty much takes care of it.
For the smoothest dipole bass, place your woofers the same distance from the wall behind them as your head is located in front of the wall behind your listening position. My abnormal room layout led to a broad suckout in the 100-200 Hz range. With proper positioning I got this result with my old H-frame: Link
As far as EQ and X-over are concerned. A single DCX2496 can fulfill both functions as far as dipole effects are concerned. If you want EQ for room issues, then I guess you'll have to add something like a DEQ2496.
I'm only using a DCX and set everything up with pink noise using a Behringer ECM8000 mic ($50), M-audio preamp ($50), and TrueRTA ($70-100). You can get things sounding pretty good that way which is really nice when they're dominating your living room while you figure out how to do it the right way.
In my situation, I'm running a low pass on my woofers at their Fs, 26Hz. This flattens the woofer response but requires you to boost the woofer level and/or lower the mid/tweet level to match. My mid is high-passed at 300Hz although the baffle width pretty much takes care of it.
For the smoothest dipole bass, place your woofers the same distance from the wall behind them as your head is located in front of the wall behind your listening position. My abnormal room layout led to a broad suckout in the 100-200 Hz range. With proper positioning I got this result with my old H-frame: Link
room issues are beyond what i've even taken into account so far. i was just considering xo/eq to smooth spikes in the mid/high range of the caire but now have noticed the extra magnets which i may consider before introducing other components.
the sub's plate amp only goes upto 160Hz, and i would like to keep it lower than that if possible due to the fact that my subs are located at the back of the room in relation to the caire's in front. crossing over at 160Hz makes it very noticable that sound is not coming from one point in the room. throws off the accuracy of the sound.
my subs are pyle ppa15's, similar to what chops used in his infamous dipole thread except mine dont seem to have the shiny coating on the cone surface and lack the banana connectors that his arrived with. I placed mine into a W frame and they produce more than enough bass without eq or extra boost with just the 2 drivers powering the low range.
i've got a decent turtle beach santa cruz sound card that i always wanted to attempt to measure my equipment with.. never got around to it though and its more fun throwing new components at my system than doing the work to refine it i guess ;/
DCX sounds interesting though i'm going to look into that.
the sub's plate amp only goes upto 160Hz, and i would like to keep it lower than that if possible due to the fact that my subs are located at the back of the room in relation to the caire's in front. crossing over at 160Hz makes it very noticable that sound is not coming from one point in the room. throws off the accuracy of the sound.
my subs are pyle ppa15's, similar to what chops used in his infamous dipole thread except mine dont seem to have the shiny coating on the cone surface and lack the banana connectors that his arrived with. I placed mine into a W frame and they produce more than enough bass without eq or extra boost with just the 2 drivers powering the low range.
i've got a decent turtle beach santa cruz sound card that i always wanted to attempt to measure my equipment with.. never got around to it though and its more fun throwing new components at my system than doing the work to refine it i guess ;/
DCX sounds interesting though i'm going to look into that.
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