Member
Joined 2003
Nope. It's pretty much standard ripole. I just call it "S"-baffle since it looks like it from the top. Scetches have both push-pull and force cancellation mathers included, just like original Phoenix woofer. Each two woofer column has them so construction shouldn't dance around and most of drivers magnet distorsion should be cancelled off the equation.
I'd like to go to that 460mm overall depth but that is pretty close to Linkwitz Phoenix project woofer:
Dipole Woofer
With it's well known peak problem:
http://www.linkwitzlab.com/images/graphics/20w2.gif
Phoenix woofer is 483mm deep and has 270Hz peak. Linkwitz used notch filter with 2nd order Linkwitz-Riley at 100Hz with it. What do you think, is 460mm steep "S" / Ripole impossible with 150Hz crossoverpoint? Say notch + 4th order Linkwitz-Riley? Such cross puts 270Hz (where Phoenix peaks) below -21dB levels which should be adequate. But how audible those pre-peak problems and little clitches are just above 150Hz?
I just experimented my mids in practice. They are now in about 220mm "D" straight baffle and play with 250Hz 2nd order Linkwitz-Riley highpass. Downside even with this crossoverpoint is that 2nd order highpass just doesn't cut off dipoles natural 12dB/oct excursion demand. Or it does but it doesn't cut it enough from low bass. So running extreme material with high level low bass material makes the cones dance quite a while. Running 120Hz or 150Hz 2nd highpass it's intolerable. 4th order 150Hz looked possible cutting excursion effective enough. But is it still too much for 460mm ripole...
My future woofers are 830669 Peerless models and I'm intrested how rugged design is it. While drivers aren't visible from any angle with the final construction there is no way knowing drivers agony before hard hits to magnet backplate and propably permanent damage.
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Member
Joined 2003
Just checked an 830669 to get a very rough idea how they handle over-excursion. Suspension (spider I think) gets very stiff past xmax. I didn't push extremely hard to find backplate, but VC didn't bottom pushing fairly hard with palms of my hands.
Haven't tried ripole, but I did have reasonable success damping dipole peak and ripple of 380mm deep dipole with heavy wool felt at rear exit. Do you have DCX you can experiment with?
One thing to try for mids would be to swap W22s for W18s. Top end is almost the same for both, and W22 would reduce excursion. WG for ribbon would get a little deeper and wider to match AC with same coverage angle, but larger WG would also be good for low end ribbon distortion.
Haven't tried ripole, but I did have reasonable success damping dipole peak and ripple of 380mm deep dipole with heavy wool felt at rear exit. Do you have DCX you can experiment with?
One thing to try for mids would be to swap W22s for W18s. Top end is almost the same for both, and W22 would reduce excursion. WG for ribbon would get a little deeper and wider to match AC with same coverage angle, but larger WG would also be good for low end ribbon distortion.
Well, hopefully they're safe. My present SS don't handle over excursions that well. One advantage is much higher SPL capacity. 17dB or so with Linkwitz xls-sheet. That's pretty dramatical..
Yep. Still have my DCX. Do you have pictures or/and measurements of your experiment? My present scetch gives 387mm total depth so it should be a bit similar setup. What kind of crossover setup did you use and what kind of overall system?
Yep. I agree. W22 would be better. But I have W18s in my present setup and I think I'll try them first. There are some off axis issues where W18 should be better than W22. 8" midrange also makes the mid MTM section higher and lifts ribbon maybe 100mm "too high" compared to ear height. Shouldn't be that big problem but I'm trying to keep it vertically as compact as possible. Ripole is already 720mm for each two driver setup so total height is about 1970mm with W18 option.
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Member
Joined 2003
All I could find were pictures of the front of the baffle - which doesn't you do much good. This was a bass module for experimenting with several different tops...coax, WGs, ribbon/Magnepan, etc. I scrapped all of these baffles for a move about 2 years ago.
BMS 18N850 in a 380mm U baffle. XO was a DCX, usually around 150-200Hz. The back of the baffle was basically an oversized Variovent. Wool felt in a "C" shape from side to side, the felt was immobilized by heavy steel screen on the inside and outside.
Ok so it was U-frame. Quite a different story to ripole. Do you have measurements from the rear side?
Unfortunately I can't use that much filling with ripole / S-baffle structure because it will hit the cones. Maybe slices in the ripole corners might work but I don't know would it do any good.
Darn these drawbacks. I'd like to run woofers up to 200-300Hz for more dynamics and slam but in ripole it just doesn't work. 2x7" is fine by normal standards but compared to 2160cm2 of 4x12" it's in a different league. I could put all drivers into wide straight baffle but then moving mass shakes the whole thing and I can't make it so well more manageable 3-part speaker. In one piece 500x2000mm baffle is pretty hard thing to move around. Ripole has push-pull and force cancellation advantages but then it limits top end extension.
Member
Joined 2003
Sorry, I couldn't find measurements from any side.
How about using your DCX to low-pass & EQ only the woofers?
How about using your DCX to low-pass & EQ only the woofers?
Good idea and I've thought of it too. Problem is the delay. Woofers are about 200mm further away to begin with and Behringer is causing some processing delay with it so it isn't that simple matching phasing and timing.
By the way how audible such cabinet ripples are in practice? In U-frame it isn't that audible since resonances are at the back and you can use some stuffing to fix them. I just thought how big sin is it to run W- or S-baffle setup all the way to their maximum without that large margin to breakup. Althought like said even Linkwitz 483mm deep W-baffles primary 270Hz is over 20dB down with 150Hz 4th order crossover and my baffles are almost 100mm smaller. Just hoping for more than 150Hz for possible top end extension. 200Hz would be ideal.
My ripole design is pretty much as compact as possible. Little over 90mm and was it 76mm openings to both front and back. Opening is under 50% of drivers cone area so basically there should be a bit pressure how sound is pushed out of the structure. I don't know the drawbacks of that and is there any advantage? Slight horn behavior with better dynamics? At least there is possibility of vibrating sidewalls even while pressure isnt't even in same league as in closed or vented systems.
My ripole design is pretty much as compact as possible. Little over 90mm and was it 76mm openings to both front and back. Opening is under 50% of drivers cone area so basically there should be a bit pressure how sound is pushed out of the structure. I don't know the drawbacks of that and is there any advantage? Slight horn behavior with better dynamics? At least there is possibility of vibrating sidewalls even while pressure isnt't even in same league as in closed or vented systems.
Jussi,
Here are my 2 cents.
In practice I found twin Scanspeak 10" never run out of excursion in my set up. Indeed, when playing organ music the cone would not move more than 1/3 of the linear excursion. Mine are housed in rather deep U-frame fully stuffed with high quality wool. The U-frame resonance is not too obvious from my measurements after playing with stuffing - sometimes just one layer less of wool would make the resonance obvious. I have only a modest 3dB boost to the bass (instead of 6dB per octave) but this already gives a nice 2nd rolloff with -3dB at around 55Hz. I don't think I have a problem of equalizing them flat to 30Hz if I wish to, but in order to reduce distortion I keep it that way and will use twin Linkwitz subs to support below 55Hz. From my memory my room (H:2.5m W5.3m L6.5m) is larger than yours and is very well damped, also with multiple large exits. So I don't think you would have any excersion problems with your twin SS woofers. My speakers are U-frame for both the mids and woofers, Dynaudio Esotar T330D, SS8531G00 7" revelator mids, SS8861T00 10" revelator woofers, and Peerless 830500 XLS subwoofers. They should have a 93-94dB sensitivity with above 120dB SPL capability above 60Hz, norminal 4R load. I will finish the 3 ways of my speakers (4 ways eventually, but still in lack of an amp to drive the mono-subs) in a few weeks time. Before that I will not publish any information.
I am currently fully engaged with other commitments so won't be able to join in the fun in this forum. I remember we exchanged quite a few posts and emails a while ago when you did your previous speakers so I am now jumping in to say hello and wish you good luck.
Regards,
Bill
Here are my 2 cents.
In practice I found twin Scanspeak 10" never run out of excursion in my set up. Indeed, when playing organ music the cone would not move more than 1/3 of the linear excursion. Mine are housed in rather deep U-frame fully stuffed with high quality wool. The U-frame resonance is not too obvious from my measurements after playing with stuffing - sometimes just one layer less of wool would make the resonance obvious. I have only a modest 3dB boost to the bass (instead of 6dB per octave) but this already gives a nice 2nd rolloff with -3dB at around 55Hz. I don't think I have a problem of equalizing them flat to 30Hz if I wish to, but in order to reduce distortion I keep it that way and will use twin Linkwitz subs to support below 55Hz. From my memory my room (H:2.5m W5.3m L6.5m) is larger than yours and is very well damped, also with multiple large exits. So I don't think you would have any excersion problems with your twin SS woofers. My speakers are U-frame for both the mids and woofers, Dynaudio Esotar T330D, SS8531G00 7" revelator mids, SS8861T00 10" revelator woofers, and Peerless 830500 XLS subwoofers. They should have a 93-94dB sensitivity with above 120dB SPL capability above 60Hz, norminal 4R load. I will finish the 3 ways of my speakers (4 ways eventually, but still in lack of an amp to drive the mono-subs) in a few weeks time. Before that I will not publish any information.
I am currently fully engaged with other commitments so won't be able to join in the fun in this forum. I remember we exchanged quite a few posts and emails a while ago when you did your previous speakers so I am now jumping in to say hello and wish you good luck.
Regards,
Bill
An externally hosted image should be here but it was not working when we last tested it.
Hi Bill! It's been a while..
Intresting concept and good looking speakers.
Few differences to my approach though:
U-frame: different radiation pattern and (at least in theory) 6dB more efficiency compared to normal dipole (no mather is is ripole, W-fram or straight baffle). Efficiency would be welcome but different radiation pattern isn't. Friend of mine tried U-baffle some time ago without that much success. Even measuring them outside didn't give that much directivity and without that I don't see that much point moving out of the closed box. And even if radiation pattern would be cardioid, which is possible with different cabinet solution, it isn't that practical since I have to place my speakers pretty close to sidewalls.
Large well damped room is another mather. It doesn't require that much directivity but it needs more pure SPL capacity to play with. Walls and other surfaces aren't that close and therefore room modes and reflections aren't that big problem.
Subwoofer assistance. This makes a lot of difference. -3dB at 55Hz with a deep U-frame compared to 340mm wide flat baffle with flat room response down to 20Hz. If I put 50Hz even 2nd or better 4th order highpass on those panels can run basically "anything". I don't know how faithful they can be to original signal but at least excursion isn't a problem.
I tried few different subwoofer setups in this room with these speakers. Never got it quite right though. Got pretty decent room responses but it didn't sound that "even" and "one". This is why I thought to go for larger 3-way and keep overall setup simpler. I know deep bass department, say from 15Hz to 30-40Hz, is always a compromisse with a dipole but I also know present plans 4x12" SLS S-frame setup has 17dB more SPL capacity than my old ones and also 6-7dB more than standard Linkwitz Orions. Push-pull configuration and force cancellation advantages should also give some edge compared to present setup. I'll just have to see how long way this is adequate.. If those prototypes work as I need them to work..
Intresting concept and good looking speakers.
Few differences to my approach though:
U-frame: different radiation pattern and (at least in theory) 6dB more efficiency compared to normal dipole (no mather is is ripole, W-fram or straight baffle). Efficiency would be welcome but different radiation pattern isn't. Friend of mine tried U-baffle some time ago without that much success. Even measuring them outside didn't give that much directivity and without that I don't see that much point moving out of the closed box. And even if radiation pattern would be cardioid, which is possible with different cabinet solution, it isn't that practical since I have to place my speakers pretty close to sidewalls.
Large well damped room is another mather. It doesn't require that much directivity but it needs more pure SPL capacity to play with. Walls and other surfaces aren't that close and therefore room modes and reflections aren't that big problem.
Subwoofer assistance. This makes a lot of difference. -3dB at 55Hz with a deep U-frame compared to 340mm wide flat baffle with flat room response down to 20Hz. If I put 50Hz even 2nd or better 4th order highpass on those panels can run basically "anything". I don't know how faithful they can be to original signal but at least excursion isn't a problem.
I tried few different subwoofer setups in this room with these speakers. Never got it quite right though. Got pretty decent room responses but it didn't sound that "even" and "one". This is why I thought to go for larger 3-way and keep overall setup simpler. I know deep bass department, say from 15Hz to 30-40Hz, is always a compromisse with a dipole but I also know present plans 4x12" SLS S-frame setup has 17dB more SPL capacity than my old ones and also 6-7dB more than standard Linkwitz Orions. Push-pull configuration and force cancellation advantages should also give some edge compared to present setup. I'll just have to see how long way this is adequate.. If those prototypes work as I need them to work..
I think my WWMTMWW plan is close to Dynaudio Evidence Master when it comes to looks:
http://tk.files.storage.msn.com/x1p...tEDK0Y3ctxE4GKMrgaVRL-4AZYH9-MaCxIkh_HR7Mg1ME
http://www.dynaudio.com/images/systems/lines/evidence/opener/DYN_Evidence_set.jpg
Original Evidence is a WWMTTMWW setup. It's 2050mm tall, 240mm wide and 580mm deep. Proportions in ripole are a bit different. Minimum 1970mm height with 280mm width and 387mm depth. Height might grow a little bit from floorplate and few other adjustments. Both 3-part setups with similar finishing looks.
http://tk.files.storage.msn.com/x1p...tEDK0Y3ctxE4GKMrgaVRL-4AZYH9-MaCxIkh_HR7Mg1ME
http://www.dynaudio.com/images/systems/lines/evidence/opener/DYN_Evidence_set.jpg
Original Evidence is a WWMTTMWW setup. It's 2050mm tall, 240mm wide and 580mm deep. Proportions in ripole are a bit different. Minimum 1970mm height with 280mm width and 387mm depth. Height might grow a little bit from floorplate and few other adjustments. Both 3-part setups with similar finishing looks.
Member
Joined 2003
True, but it should be a reasonable way to test prototype baffles to see if you are satisfied with peak suppression before committing to expensive passive LF parts. Even with passive you will still have to deal with some delay.
I'd experiment with a wool felt LPF at the rear outlet of the ripole. A flat piece of wool felt would require stiffer support than the curved wire screen I used...maybe small metal or plastic grates. Perhaps the best trade-off would be a combination of acoustic and electrical solutions???
I won't be going passive at any point. Maybe I'll replace Behringer with proper active filter at some point but not passive.
Maybe if there is space for the damping. In my case ripole is pretty much as small as it can be so without hitting driver cones it's pretty tight solution to fit there anything.
Ok. Some prototypes measured. First Fountek Pro5i in first waveguide proto. Looks rather promissing. 20 deg off axis shows that on axis response suffers from some diffraction that should be fixed. 60 and 90 degree responses look very controlled and balance stays very stable while going off axis. Good start. Some eq around 2kHz and 10kHz, 1,2kHz 4th order Linkwitz-Riley highpass.
Second is my S-baffle / ripole setup. Presently 355mm deep, growing to 387mm total in final design. Measured from front exit of the system. Individual graphs show natural response, response with notch filter, response with notch and 6dB/oct (Behringer LP6 +15dB @ 25Hz) dipole eq and finally all these with 180Hz 4th order Linkwitz-Riley lowpass. Pretty similar results that Linkwitz himself got from his Phoenix W-baffle:
System Test
That 15dB @ 25Hz seemed pretty adequate compensation in actual situation and room response looked flat down to 30Hz going few dB down to 20Hz.
Final graph shows difference between rear and front exit of the system since construction isn't 100% symmetrical. Not that much difference though so it should work..
Measuring these things dipole behavior and nulls isn't that easy. At least in room. But listening them closely from front and then move to 90 degrees off axis clearly demonstrated dipolar behavior just as it should be. I don't know does this still create wider dipole "eights" that other solutions. At least at some of it's range with that 180Hz lowpass. Any experience from such things?
With single driver cabinet vibrates quite a bit with large excursions of 830669 SLS. Movement is in sideways like the driver is fitted. Unfortunately I don't have a pair in same level so the driver that is suppose to cancel vibration and shake the set to opposite direction. I'll have to wait and see how it turns out. At least supporting system to floor and adding weight seemed to help even with single driver. I can't even imagine how much say WWMTMWW setup with straight baffle and all cones moving same direction would shake..
There is also quite a large amount of air coming from the exits while playing large excursions. You can clearly feel it with hand. Not a similar thing as playing 12" cone in a free air. There must be some pressure in the ripole and construction just pushes air from the exits with pressure. I don't know how that effects on resolution, dynamics and so on..
Second is my S-baffle / ripole setup. Presently 355mm deep, growing to 387mm total in final design. Measured from front exit of the system. Individual graphs show natural response, response with notch filter, response with notch and 6dB/oct (Behringer LP6 +15dB @ 25Hz) dipole eq and finally all these with 180Hz 4th order Linkwitz-Riley lowpass. Pretty similar results that Linkwitz himself got from his Phoenix W-baffle:
System Test
That 15dB @ 25Hz seemed pretty adequate compensation in actual situation and room response looked flat down to 30Hz going few dB down to 20Hz.
Final graph shows difference between rear and front exit of the system since construction isn't 100% symmetrical. Not that much difference though so it should work..
Measuring these things dipole behavior and nulls isn't that easy. At least in room. But listening them closely from front and then move to 90 degrees off axis clearly demonstrated dipolar behavior just as it should be. I don't know does this still create wider dipole "eights" that other solutions. At least at some of it's range with that 180Hz lowpass. Any experience from such things?
With single driver cabinet vibrates quite a bit with large excursions of 830669 SLS. Movement is in sideways like the driver is fitted. Unfortunately I don't have a pair in same level so the driver that is suppose to cancel vibration and shake the set to opposite direction. I'll have to wait and see how it turns out. At least supporting system to floor and adding weight seemed to help even with single driver. I can't even imagine how much say WWMTMWW setup with straight baffle and all cones moving same direction would shake..
There is also quite a large amount of air coming from the exits while playing large excursions. You can clearly feel it with hand. Not a similar thing as playing 12" cone in a free air. There must be some pressure in the ripole and construction just pushes air from the exits with pressure. I don't know how that effects on resolution, dynamics and so on..
Attachments
Plan proceeds. SLS drivers sold and original dipole-cardioid WWMTMWW idea scrapped.
Going for full scale WWMTM. Wilson Alex style. Already scetched bass cabinet that can hold twin BMS 15S330 woofers in vented setup. 200 litres, 30Hz. Adding MTM top with W18E001 Seas and Pro5i Founteks. Crosses around 200-300Hz and 1200-1400Hz. Propably 2nd and 4th Linkwitz-Riley.
Overview
I read original "daddy" review. Stereophiles archives Grand SLAMM test. It said that SLAMMs cabinet vent maximum output is around 24Hz and text indicates that this would be the tuning frequency. But according to LspCAD and WinISD both claim around 30Hz tuning gives max vent output around 23-25Hz. Which source is correct?
Wilson Audio Specialties X-1/Grand SLAMM loudspeaker system Page 3 | Stereophile.com
I thought to use mids also in vented cabinets. Not because of cone excursion but to experiment how does it effect on sound openess and overall imaging since there is also some midrange frequences coming out of the rear ports. This also allows using just the MTM top for low level nighttime listening (with separated DCX mem-setup) Also using Seas 27mm aluminium in a waveguide for rear tweeter.
Front port for woofers. Post slot type so it fits in lower space and still obtains enough area to operate within drivers linear excursion range with low compression and turbulence noise. According to WinISD running 2xS330 to their max linear excursion, +-8mm, gives around 20m/s airspeed in 36x11cm reflexport. With anything usable at amplifier sector, for example 2x200W @ 4 ohm, reduces this to around 10m/s and keeps max excursions around 50% of the max. Should be silent, low distorsion and still plenty of headroom.
Bass cabinet is about 100cm tall, 45cm wide and rather massive 75cm deep. Adding mid and tweeter sections rises the overall height to around +170cm. Mid and tweeter sections separated just like Alex so they can be focuced towards the listener. At least the ribbon needs to be tilted down a bit to keep it in range with 3m or so listening distance.
What do you think?
Going for full scale WWMTM. Wilson Alex style. Already scetched bass cabinet that can hold twin BMS 15S330 woofers in vented setup. 200 litres, 30Hz. Adding MTM top with W18E001 Seas and Pro5i Founteks. Crosses around 200-300Hz and 1200-1400Hz. Propably 2nd and 4th Linkwitz-Riley.
Overview
I read original "daddy" review. Stereophiles archives Grand SLAMM test. It said that SLAMMs cabinet vent maximum output is around 24Hz and text indicates that this would be the tuning frequency. But according to LspCAD and WinISD both claim around 30Hz tuning gives max vent output around 23-25Hz. Which source is correct?
Wilson Audio Specialties X-1/Grand SLAMM loudspeaker system Page 3 | Stereophile.com
I thought to use mids also in vented cabinets. Not because of cone excursion but to experiment how does it effect on sound openess and overall imaging since there is also some midrange frequences coming out of the rear ports. This also allows using just the MTM top for low level nighttime listening (with separated DCX mem-setup) Also using Seas 27mm aluminium in a waveguide for rear tweeter.
Front port for woofers. Post slot type so it fits in lower space and still obtains enough area to operate within drivers linear excursion range with low compression and turbulence noise. According to WinISD running 2xS330 to their max linear excursion, +-8mm, gives around 20m/s airspeed in 36x11cm reflexport. With anything usable at amplifier sector, for example 2x200W @ 4 ohm, reduces this to around 10m/s and keeps max excursions around 50% of the max. Should be silent, low distorsion and still plenty of headroom.
Bass cabinet is about 100cm tall, 45cm wide and rather massive 75cm deep. Adding mid and tweeter sections rises the overall height to around +170cm. Mid and tweeter sections separated just like Alex so they can be focuced towards the listener. At least the ribbon needs to be tilted down a bit to keep it in range with 3m or so listening distance.
What do you think?
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