SY said:
I'd been thinking about this.
The idea that came to mind, would be front- and rear-firing horn mids, wired in INVERSE polarity, to make a sort of "dipole horn". With the dispersion patterns of the horns, you could adust the relative level of the rear horn, to "duplicate" the rear-radiation of the dipole/H-frame (which is more a "cardioid" than a true dipole, IIRC, and therefore has slightly different front- and rear- dispersion characteristics).
Yep, it's a LOT of hardware... but the idea of a "dipole horn" just keeps popping back up in my mind. Guess I'll eventually have to try building such a setup myself...
Regards,
Gordon.
Attachments
GordonW said:
Easy - Just get the big Heils - they've been around a long time, easily available and have the horn built in, mate it with an open baffle mid and you are ahead of the game by a mile. *Maybe* a pair of large format TAD's in two back to back round tractrix horns would sound better - I doubt it.
The nice thing about seperate front and back drivers, would be the ability to level-adjust the rear one, to simulate cardioid response and the like. Also, the rear horn could be narrower dispersion than the front... nothing to stop asymmetric flares, except the budget. 
Wonder how a passel of those TangBand 3" drivers in a dipole line-horn would sound? No, they're not that efficient solo... but say, FIFTY of them? Now we're talking better efficiency. Or, as Pete at work here has mentioned- Jim Strickland of Acoustat once had an idea, of dipole-horn-loading a narrow PLANAR driver... now, THAT could be interesting... it'd bring the efficiency of one of those, probably, up significantly, while reducing the main deficiency of planars- the tendency for the membrane to be driven too hard and hit the plates...
Regards,
Gordon.
Wonder how a passel of those TangBand 3" drivers in a dipole line-horn would sound? No, they're not that efficient solo... but say, FIFTY of them? Now we're talking better efficiency. Or, as Pete at work here has mentioned- Jim Strickland of Acoustat once had an idea, of dipole-horn-loading a narrow PLANAR driver... now, THAT could be interesting... it'd bring the efficiency of one of those, probably, up significantly, while reducing the main deficiency of planars- the tendency for the membrane to be driven too hard and hit the plates...
Regards,
Gordon.
A local guy has BIG horn front/rear loaded Soundlab electrostats -- they are different- not my choice - they are from the factory and maybe 30 years old.
I stacked eight of the Heils and made both front/back cardboard conical flares for them - worked well down to 800 cycles. About a 50" horn loaded dipole line - I like a single one with the factory flare better though.
I stacked eight of the Heils and made both front/back cardboard conical flares for them - worked well down to 800 cycles. About a 50" horn loaded dipole line - I like a single one with the factory flare better though.
Stacking Heils is something that would be cool, if it were possible. I'd like to, sometime, accumulate enough ESS AMT-1 Heil tweeters, to make a pair of 6 foot tall stacks, and THEN horn-load that. Could be absolutely devastating...
Hmmm... the discussion of the fellow having problems with rising response on the Neo 8 planars makes me think... if you HORN LOADED the Neo8s, that rising response would be COUNTERACTED by the gain of the flare at LF... they'd be counter-acting slopes. Wonder how THAT would sound in a dipole horn???
Regards,
Gordon.
Hmmm... the discussion of the fellow having problems with rising response on the Neo 8 planars makes me think... if you HORN LOADED the Neo8s, that rising response would be COUNTERACTED by the gain of the flare at LF... they'd be counter-acting slopes. Wonder how THAT would sound in a dipole horn???
Regards,
Gordon.
Magnetar
Did you see my posts yesterday re KKs - on suitability of P.Audio specs & sealed vs back chamber??
Thanks kindly
I see those Neo 8s are only 90 dB and flat c. 1 - 8 kHz, unless notched around 11 kHz.
We need to work out what TS params would work best: I guess they may not be any different from what you would put in a normal horn.
Did you see my posts yesterday re KKs - on suitability of P.Audio specs & sealed vs back chamber??
Thanks kindly
I see those Neo 8s are only 90 dB and flat c. 1 - 8 kHz, unless notched around 11 kHz.
We need to work out what TS params would work best: I guess they may not be any different from what you would put in a normal horn.
rick57 said:Magnetar
you said (in an earlier thread “Best bass 50 – 500 Hz”)
- using Baldwin organ field coil bass drivers “the original design calls for a reflex back chamber . . the Klam is sealed”
What experience do you have to suggest when to seal, when to use a back chamber?
Cheers
I put the Baldwin field coils back in the Klams for giggles this morning and opened up the ports - I was driving them before with a PP EL84 amp (bout 12 watts) and was afraid to hook them to the 250 watt sand amp for fear I'd melt them - they trounce the Altecs. They seem to take the power fine seeing they are quite a bit more sensitive and the amp is barely working. Next I'll try my little Robertson 4010 70 watter. It's really got good bass control. The field coils have a quality to them that can I can best describe as being wayyyyy less veiled and closer to live feed. The upper bass low midrange ultra transparent yet musical, relaxed but highly dynamic and 'fast.' It's a beautiful thing. Seem to sound best at around 95 volts DC on the FC.
Re. vents: If you don't use subs tune the klam back chamber like a reflex to around 10 cycles above the drivers resonance peak in free air.
The Eminence or or P Audios should be fine. I'd go with the more sensitive of the two.
If you went down this route in a domestic situation, the costs of doubling up drivers add up.
As SL’s H baffle woofers are probably barely 90 dB efficient, even though it would be active:
rather than look for mids & HE units > 100 dB, a sensible compromise may be mids & HE around 93-96 dB. Horn loaded they’ll be about 100 dB, still more than adequate for most situations.
The Eminence Alpha, Audax PR170 or PHL 6 inchers could all be good. They could cover say 300 Hz to 2.5- maybe 3.5 kHz.
One inch Beyma/ P.Audio/ BMS could easily do the rest.
(In lieu of XLSs in the H baffle dipoles, consider the TC Sounds TC12+, or 2nd hand pro 15 inchers).
As SL’s H baffle woofers are probably barely 90 dB efficient, even though it would be active:
rather than look for mids & HE units > 100 dB, a sensible compromise may be mids & HE around 93-96 dB. Horn loaded they’ll be about 100 dB, still more than adequate for most situations.
The Eminence Alpha, Audax PR170 or PHL 6 inchers could all be good. They could cover say 300 Hz to 2.5- maybe 3.5 kHz.
One inch Beyma/ P.Audio/ BMS could easily do the rest.
(In lieu of XLSs in the H baffle dipoles, consider the TC Sounds TC12+, or 2nd hand pro 15 inchers).
Hi rick57, I just came across this thread. How far have you now got with your suggested route?
If you are still considering things, I wouldn't be put off trying dipole bass with a horn mid/top. My set up works superbly, and I'd say unless anyone can share real experiences with similar combinations, then no amount of theroising can substitue for trying it!
My comments on your first post are that I would diffinitely not mix a sealed box in between a horn and ribbon top. I'd go for a simpler 3 way set-up if possible.
Will the JBL/horn not go up to 3000hz? Also, I'd cross them over at lower than 300hz if you can. I am saying this more from room/interaction theory and real experience of mixing these techniques rather than knowing the horn that you propose to use.
So your mid-horn might need to change accordingly. I also believe that a well designed round horn is a far better solution but this is a whole separate subject!
What I have found though is that the closer to 300hz you get with dipoles (assuming a gentle cross-over slope) the more likeliehood of mid-range "confusion" - this is the point where the "diffuse" range of a room often starts and therefore interaction will occur.
Cheers,
Jonathan
If you are still considering things, I wouldn't be put off trying dipole bass with a horn mid/top. My set up works superbly, and I'd say unless anyone can share real experiences with similar combinations, then no amount of theroising can substitue for trying it!
My comments on your first post are that I would diffinitely not mix a sealed box in between a horn and ribbon top. I'd go for a simpler 3 way set-up if possible.
Will the JBL/horn not go up to 3000hz? Also, I'd cross them over at lower than 300hz if you can. I am saying this more from room/interaction theory and real experience of mixing these techniques rather than knowing the horn that you propose to use.
So your mid-horn might need to change accordingly. I also believe that a well designed round horn is a far better solution but this is a whole separate subject!
What I have found though is that the closer to 300hz you get with dipoles (assuming a gentle cross-over slope) the more likeliehood of mid-range "confusion" - this is the point where the "diffuse" range of a room often starts and therefore interaction will occur.
Cheers,
Jonathan
Hi Jonathan
(Progress on projects is all too slow here. I’m 70% through finishing SL's Phoenix first. The hybrid is for a room where I’m waiting for the draftsperson to draw it up).
As the PHL 1010s were on sale from Zalytron I ordered a pair, though since then see that Madisound have the similar Audax PR170MOs at the same price, with for my project slightly better specs.
Thanks for your encouragement on mixing horns & dipoles. John Hancock has combined the Unity + dipole bass with apparent success.
>I would diffinitely not mix a sealed box in between a horn and ribbon top. I'd go for a simpler 3 way set-up if possible
I agree with your intent, except the JBL/horn would not go up to 3000 Hz. JBL say about 1200, but I think I’d probably need to develop a phase plug to do it (and I only learnt PPs could extend response a few months ago - -learning curve).
I think it would be easier to make flares for PHLs.
> I'd cross the JBLs over at lower than 300 Hz
I have 182 Hz flares, I expect I could possibly go to 220-240 Hz.
Can you done describe what have you done, especially what didn’t work & what worked best?
Cheers
(Progress on projects is all too slow here. I’m 70% through finishing SL's Phoenix first. The hybrid is for a room where I’m waiting for the draftsperson to draw it up).
As the PHL 1010s were on sale from Zalytron I ordered a pair, though since then see that Madisound have the similar Audax PR170MOs at the same price, with for my project slightly better specs.
Thanks for your encouragement on mixing horns & dipoles. John Hancock has combined the Unity + dipole bass with apparent success.
>I would diffinitely not mix a sealed box in between a horn and ribbon top. I'd go for a simpler 3 way set-up if possible
I agree with your intent, except the JBL/horn would not go up to 3000 Hz. JBL say about 1200, but I think I’d probably need to develop a phase plug to do it (and I only learnt PPs could extend response a few months ago - -learning curve).
I think it would be easier to make flares for PHLs.
> I'd cross the JBLs over at lower than 300 Hz
I have 182 Hz flares, I expect I could possibly go to 220-240 Hz.
Can you done describe what have you done, especially what didn’t work & what worked best?
Cheers
Hi there,
>I agree with your intent, except the JBL/horn would not go up to >3000 Hz. JBL say about 1200, but I think I’d probably need to >develop a phase plug to do it (and I only learnt PPs could >extend response a few months ago - -learning curve).
>I think it would be easier to make flares for PHLs.
A horn for the PHL's would be best, if you are using a phase plug then it suggests that those frequencies would not be horn loaded.
>I have 182 Hz flares, I expect I could possibly go to 220-240 Hz.
That should be fine as a crossover over frequency, you may need a steeper rate for this then (2nd order upwards).
>Can you done describe what have you done, especially what >didn’t work & what worked best?
I'm not sure if you seen these but here are pictures if not;
http://www.kingdom.uk.com/jdfiles/side_open_right_full.jpg
http://www.kingdom.uk.com/jdfiles/in_room_close_full1.jpg
The dipoles are rolling off at the moment at 160hz. In theory this is lower than it should be (the horns -3db is 200hz) but there's some room gain helping things. The Lambda TD15's are driven by an ICEpower class D amp per side (600W).
The Oris horns are again at the moment running full range by a low power valve amp (1.5 watts at the moment!). But gain I'm experimenting rolloing them off at 160hz to lower distortion, and this seems a good way to go.
At the moment that's all there is, but I am also going to try rolling the Oris off at something upwards of 5khz with maybe a compression driver/horn (Vitavox S2).
In terms of what I tried in this room, pretty well most different types of box, open panel, and horn speaker! Both expensive commercial ones and various DIY designs. I haven't used large bass horns though, only Lowther (or AER) backloaded ones.
For sure full range dipoles do not work well in my room. Some may of course like the effect they produce, but not me - it sounds unnatural.
The position of the dipole driver/baffle is critical. And the layout you see in the pics are not accidental (ok at first they were, trying to get 15" or 18" drivers into a compact space!). I tried many orientations of speakers, and these sound by far the best. I think thats one benefit of a horn on top if you mount the in a way that means the dipoles can be turned to suit the room. The was a speaker made by Gradient that was very similar to this concept - a sealed mid/top unit on top of a triangular column dipole.
I guess that's it - do let me know if you have any more questions or comments.
Cheers,
Jonathan
>I agree with your intent, except the JBL/horn would not go up to >3000 Hz. JBL say about 1200, but I think I’d probably need to >develop a phase plug to do it (and I only learnt PPs could >extend response a few months ago - -learning curve).
>I think it would be easier to make flares for PHLs.
A horn for the PHL's would be best, if you are using a phase plug then it suggests that those frequencies would not be horn loaded.
>I have 182 Hz flares, I expect I could possibly go to 220-240 Hz.
That should be fine as a crossover over frequency, you may need a steeper rate for this then (2nd order upwards).
>Can you done describe what have you done, especially what >didn’t work & what worked best?
I'm not sure if you seen these but here are pictures if not;
http://www.kingdom.uk.com/jdfiles/side_open_right_full.jpg
http://www.kingdom.uk.com/jdfiles/in_room_close_full1.jpg
The dipoles are rolling off at the moment at 160hz. In theory this is lower than it should be (the horns -3db is 200hz) but there's some room gain helping things. The Lambda TD15's are driven by an ICEpower class D amp per side (600W).
The Oris horns are again at the moment running full range by a low power valve amp (1.5 watts at the moment!). But gain I'm experimenting rolloing them off at 160hz to lower distortion, and this seems a good way to go.
At the moment that's all there is, but I am also going to try rolling the Oris off at something upwards of 5khz with maybe a compression driver/horn (Vitavox S2).
In terms of what I tried in this room, pretty well most different types of box, open panel, and horn speaker! Both expensive commercial ones and various DIY designs. I haven't used large bass horns though, only Lowther (or AER) backloaded ones.
For sure full range dipoles do not work well in my room. Some may of course like the effect they produce, but not me - it sounds unnatural.
The position of the dipole driver/baffle is critical. And the layout you see in the pics are not accidental (ok at first they were, trying to get 15" or 18" drivers into a compact space!). I tried many orientations of speakers, and these sound by far the best. I think thats one benefit of a horn on top if you mount the in a way that means the dipoles can be turned to suit the room. The was a speaker made by Gradient that was very similar to this concept - a sealed mid/top unit on top of a triangular column dipole.
I guess that's it - do let me know if you have any more questions or comments.
Cheers,
Jonathan
You could just about say you’ve left no stone unturned.
I think I saw your thread about 5-6 months ago, and at the time thought why put low efficiency dipoles ‘under’ high efficiency horns?? Not sure if you mentioned the hugely different amp powers then, but acoustically dipoles give most benefit < 200 Hz, so I now believe it’s the way to go.
> A horn for the PHLs would be best, if you are using a phase plug then it suggests that those frequencies would not be horn loaded
No, eg some Lowthers & the The Avantgarde Solo use phase plugs, though I learnt of it from a helpful chap Greame at www.centauriaudio.com.au/diy/
Who explains there how he extends the range of horn mids with them.
What is you valve amp, a 45 something?
Cheers
I think I saw your thread about 5-6 months ago, and at the time thought why put low efficiency dipoles ‘under’ high efficiency horns?? Not sure if you mentioned the hugely different amp powers then, but acoustically dipoles give most benefit < 200 Hz, so I now believe it’s the way to go.
> A horn for the PHLs would be best, if you are using a phase plug then it suggests that those frequencies would not be horn loaded
No, eg some Lowthers & the The Avantgarde Solo use phase plugs, though I learnt of it from a helpful chap Greame at www.centauriaudio.com.au/diy/
Who explains there how he extends the range of horn mids with them.
What is you valve amp, a 45 something?
Cheers
>You could just about say you’ve left no stone unturned.
Not really. I've done what I can within the very limited paramters of my technical knowledge. The best help has come by learning and plagiarising from the efforts of others!
These threads are interesting, have you read these?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=53407&perpage=10&pagenumber=2
and
http://www.diyaudio.com/forums/showthread.php?s=&threadid=25568
I too looked into the Unity horns, and would love to hear some myself.
>What is you valve amp, a 45 something?
Three lower power amps at the moment: two 2A3 SET's and the one in the system right now is a Transcendent Sound SE OTL. A 45 amp is currently in construction (probably will be for some time!). I am aiming for this to be able to run VT25A's as well.
Cheers,
Jonathan
Not really. I've done what I can within the very limited paramters of my technical knowledge. The best help has come by learning and plagiarising from the efforts of others!
These threads are interesting, have you read these?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=53407&perpage=10&pagenumber=2
and
http://www.diyaudio.com/forums/showthread.php?s=&threadid=25568
I too looked into the Unity horns, and would love to hear some myself.
>What is you valve amp, a 45 something?
Three lower power amps at the moment: two 2A3 SET's and the one in the system right now is a Transcendent Sound SE OTL. A 45 amp is currently in construction (probably will be for some time!). I am aiming for this to be able to run VT25A's as well.
Cheers,
Jonathan
GordonW said:
Too wierd. I'm actually experimenting with something like this now, although just 'simply' front loaded. There is a post from a couple years back on another thread on diyaudio where someone put some Neo 8's in a conical, and reported decent results, albeit with eq:
http://www.diyaudio.com/forums/showthread.php?s=&postid=176221&highlight=#post176221
I have some of the Monsoon planar multimedia speakers, and slapped them in a quick conical prototype. I don't think you'll ever get planars flat without eq, but my Monsoons look to be potentially useable from maybe as low as 300 up to 10k. See here:
http://htguide.com/forum/showthread.php4?p=165067#post164906
Now, a horn on the front AND the back would make for a pretty freakin big system if you want to go anywhere near that low. Figure 24-30" deep by 16-18" wide, and then you'll need a ton of room behind them.
The practical problem with horn/waveguide loaded line arrays is how to mate the midbass drivers to it, since now your midrange array is so big - you probably can't just put a midbass tower beside it. If a Unity style loading will work, then no problem. However, I'm worried about intermodulation - see my question on the htguide thread.
dwk123 said:
Dipoles are not a good thing as freq. increases (above 200 Hz or so) with regard to room interaction (..though the lack of cone reflections and velocity characteristics are good).
You might want to look here as an alternative to (traditional) front horn loading (and I'm not sure if this config. is back horn loaded OR if there are additonal drivers in push-pull that ARE being loaded with a front horn):
http://www.audio-consulting.ch/Dulcet.htm
As to a mid-bass line array tower - I don't see a problem with that at all (particularly with a dipole because of a complimentary radidation pattern in the forward plane).
Claimed for the Dulcet:
“No typical horn sound beacuse medium and high frequencies
are radiated directly without the need for travelling through the horn”
Maybe so, but I thought a typical horn sound could be avoided by known (eg) Edgar principles. It may be simpler than eg a Unity, but does not get horn loading.
“20 gr of moving mass for a very fast bass reproduction”.
A trade-off with motor strength & bass depth.
Cheers
“No typical horn sound beacuse medium and high frequencies
are radiated directly without the need for travelling through the horn”
Maybe so, but I thought a typical horn sound could be avoided by known (eg) Edgar principles. It may be simpler than eg a Unity, but does not get horn loading.
“20 gr of moving mass for a very fast bass reproduction”.
A trade-off with motor strength & bass depth.
Cheers
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