Edgar Posted April 10, 2015 Share Posted April 10, 2015 what about using two smaller driver instead of one? There's certainly room for two 12" drivers. And the right drivers might extend the high frequency capabilities by a significant amount. In the end, though, the limiting factor on the HF performance will likely be the folds -- reflections, resonances, standing waves. Quote Link to comment Share on other sites More sharing options...
djk Posted April 10, 2015 Share Posted April 10, 2015 "There's certainly room for two 12" drivers. And the right drivers might extend the high frequency capabilities by a significant amount. In the end, though, the limiting factor on the HF performance will likely be the folds -- reflections, resonances, standing waves." How about two 12's with one smooth 90° bend (B&C 12PE32)? Crossover at 90hz to your subwoofers, 900hz to your 1" elliptical Tractrix HF horn and driver. Faital Pro HF10AK and LTH102 (available from Bob Crites). 1 Quote Link to comment Share on other sites More sharing options...
xrk971 Posted April 10, 2015 Share Posted April 10, 2015 You want dual drivers? I'll give you dual drivers... hehehe... One of my favorite 12in sub drivers is the Faital Pro 12HP1030, rated at 2kW peak, 1kW rms, with 12.5mm xmax and 95dB sensitivity. Let's put two of these in parallel for 4 ohm nominal load. Increase the throat from 13in tall to 26in tall, and increase the height of the first segment of the horn appropriately to 26in tall expanding to 30in tall at the corner and skip the compound curves (which I argue are not even necessary for a good single driver design). I still like running max SPL sims because as a pro audio sound reinforcement system, that is what it's all about. For home use, you don't need drivers and horns like this as 10 watts would have the cops calling. Ok, so here is the predicted peak SPL limited by 4kW (max) thermal rating: This is some serious SPL with 140dB capability from two 12in drivers in a single box. This is the corresponding cone displacement, only 9mm of the 12.5mm allowed: And here is the electrical power input. As usual, 24dB/oct LPF and HPF are used at 60.5Hz and 700Hz, respectively: For sustained max SPL, we limit the drive to 72 volts RMS for 137dB - still pretty crazy high: Yes, window frames and plaster walls would all be obliterated inside a regular home if this was applied. Kind of like a demolition machine for renovation work... Quote Link to comment Share on other sites More sharing options...
Edgar Posted April 10, 2015 Share Posted April 10, 2015 How about two 12's with one smooth 90° bend (B&C 12PE32)? 12PE32 (or 12PE31 -- no longer available) or EVM12L are exactly what I would have recommended. Quote Link to comment Share on other sites More sharing options...
Edgar Posted April 10, 2015 Share Posted April 10, 2015 I still like running max SPL sims because as a pro audio sound reinforcement system, that is what it's all about. For home use, you don't need drivers and horns like this as 10 watts would have the cops calling. I understand -- I used to work for Mark IV Audio (Altec Lansing, University, Electro-Voice, et. al.). But it's all about the context. BTW (context again); I've been running the simulations in Pi space because I'm assuming a floor and a wall. I notice that you're running 2Pi, presumably because you're not assuming a wall. Both are valid; I just wanted to point out that there will be some minor differences between our simulations because of it. Quote Link to comment Share on other sites More sharing options...
moray james Posted April 10, 2015 Author Share Posted April 10, 2015 "There's certainly room for two 12" drivers. And the right drivers might extend the high frequency capabilities by a significant amount. In the end, though, the limiting factor on the HF performance will likely be the folds -- reflections, resonances, standing waves." How about two 12's with one smooth 90° bend (B&C 12PE32)? Crossover at 90hz to your subwoofers, 900hz to your 1" elliptical Tractrix HF horn and driver. Wow: that is impressive more info please. Best regards Moray James. Faital Pro HF10AK and LTH102 (available from Bob Crites). Quote Link to comment Share on other sites More sharing options...
Edgar Posted April 10, 2015 Share Posted April 10, 2015 Wow: that is impressive more info please. Best regards Moray James. 2x EVM12L in black; 2x 12PE32 in gray. All other parameters as before. Quote Link to comment Share on other sites More sharing options...
djk Posted April 11, 2015 Share Posted April 11, 2015 JBL 2202, E120, etc would also work. Quote Link to comment Share on other sites More sharing options...
Edgar Posted April 11, 2015 Share Posted April 11, 2015 JBL 2202, E120, etc would also work. Outstanding drivers, but AFAIK no longer in production. Quote Link to comment Share on other sites More sharing options...
The Dude Posted April 11, 2015 Share Posted April 11, 2015 Wow: that is impressive more info please. Best regards Moray James. 2x EVM12L in black; 2x 12PE32 in gray. All other parameters as before. Is this modeled in the University or are we starting to build a different speaker? I ask do to DJK's response. "There's certainly room for two 12" drivers. And the right drivers might extend the high frequency capabilities by a significant amount. In the end, though, the limiting factor on the HF performance will likely be the folds -- reflections, resonances, standing waves." How about two 12's with one smooth 90° bend (B&C 12PE32)? Crossover at 90hz to your subwoofers, 900hz to your 1" elliptical Tractrix HF horn and driver. Faital Pro HF10AK and LTH102 (available from Bob Crites). I like the Faital pro hf200 on the EV HP640 Quote Link to comment Share on other sites More sharing options...
Marvel Posted April 11, 2015 Share Posted April 11, 2015 (edited) One of my favorite 12in sub drivers is the Faital Pro 12HP1030, rated at 2kW peak, 1kW rms, with 12.5mm xmax and 95dB sensitivity. Let's put two of these in parallel for 4 ohm nominal load. Increase the throat from 13in tall to 26in tall, and increase the height of the first segment of the horn appropriately to 26in tall expanding to 30in tall at the corner and skip the compound curves (which I argue are not even necessary for a good single driver design). I still like running max SPL sims because as a pro audio sound reinforcement system, that is what it's all about. For home use, you don't need drivers and horns like this as 10 watts would have the cops calling. Seriously, a 150 watt woofer works fine for me and even then, it's overkill. That would go for most of the horn folks here. My amps might not make your favorite speaker begin to move, so it's pointless to include them in this thread, isn't it? Bruce Edited April 11, 2015 by Marvel Quote Link to comment Share on other sites More sharing options...
xrk971 Posted April 11, 2015 Share Posted April 11, 2015 Yes, I come from the sub woofer forum on diyAudio and there, they are all about Max SPL. Probably a 50 watt woofer is all you ever need. I built a full range tractrix synergy and it is so efficient that I never turned it up past 10 o'clock as it was too loud at 108dB at 1 watt. http://www.diyaudio.com/forums/full-range/261427-presenting-trynergy-full-range-tractrix-synergy.html Quote Link to comment Share on other sites More sharing options...
The Dude Posted April 11, 2015 Share Posted April 11, 2015 I will say, these are the threads I love. Especially when speakers like this come alive. Quote Link to comment Share on other sites More sharing options...
djk Posted April 11, 2015 Share Posted April 11, 2015 (edited) "Is this modeled in the University or are we starting to build a different speaker? I ask do to DJK's response. " No, it's something new. The University is tough to get the throat area right, and in practice forces you to use a low crossover point. It has no real bass, so what's the point? Starting with a fresh sheet of paper we can do something simple that will not have complex compound angles, not have so many folds, and keep the width of the one bend in the new design so narrow that it can go high enough to meet a 1" driver that can be selected on its VHF response, rather than how well it handles the midrange. This would be the general idea (push-pull to eliminate even-order harmonic distortion, and act like a phase-plug). "I like the Faital pro hf200 on the EV HP640" I'll bet that sounds great. "Outstanding drivers, but AFAIK no longer in production" What do you suggest from EV, now that the EVM DL12X is out-of-production? The EVM 12L Classic is about $100 more than the B&C 12PE32. EVM-12L CLASSIC EVM-12L CLASSIC Edited April 11, 2015 by djk 1 Quote Link to comment Share on other sites More sharing options...
xrk971 Posted April 11, 2015 Share Posted April 11, 2015 Djk, Interesting design there. For push pull to work properly doesn't there have to be symmetry in how they are mounted? The rear chamber of the top driver also needs to be same volume as the triangular chamber of the bottom one. Also, the goal of having a higher xo point to reach a 1in CD would mean being able to go up to 1kHz. Above 500Hz, sounds going through sharp corners, magnet baskets, and reflecting off narrow throat channels won't sound good - too colored and reverberant. I had a great folded bass horn that worked in the 30Hz to 300Hz range. I made a mid version of it by scaling it smaller to go from 100Hz to 1kHz. It sounded awful - nasally and reverberant. All the corners and narrow passages and reflections on the many turns. Mid horns need to be round and smooth. Quote Link to comment Share on other sites More sharing options...
Edgar Posted April 11, 2015 Share Posted April 11, 2015 Wow: that is impressive more info please. Best regards Moray James. 2x EVM12L in black; 2x 12PE32 in gray. All other parameters as before. Is this modeled in the University or are we starting to build a different speaker? I ask do to DJK's response. My response was for two EVM12L or two 12PE32 in an otherwise unmodified University Classic. DJK's response was for an entirely different horn. 1 Quote Link to comment Share on other sites More sharing options...
Edgar Posted April 11, 2015 Share Posted April 11, 2015 "Outstanding drivers, but AFAIK no longer in production" What do you suggest from EV, now that the EVM DL12X is out-of-production? The EVM 12L Classic is about $100 more than the B&C 12PE32. The EV EVM12L, and B&C 12PE32 and 12PE31 (discontinued) are the best-performing (on paper) 12" horn drivers that I am aware of. There may be others that I am not aware of. 1 Quote Link to comment Share on other sites More sharing options...
sheltie dave Posted April 11, 2015 Share Posted April 11, 2015 Moray, do you need a University, fully loaded? I have one I want to unload. 1 Quote Link to comment Share on other sites More sharing options...
moray james Posted April 11, 2015 Author Share Posted April 11, 2015 Moray, do you need a University, fully loaded? I have one I want to unload. Thank you Sheltie Dave If I had the room I would be interested but I don't have near enough space as it is. That would also be a big skid load to ship all the way to Calgary. Someone here should jump on this monster machine. est regards Moray James. Quote Link to comment Share on other sites More sharing options...
moray james Posted April 11, 2015 Author Share Posted April 11, 2015 "Is this modeled in the University or are we starting to build a different speaker? I ask do to DJK's response. " No, it's something new. The University is tough to get the throat area right, and in practice forces you to use a low crossover point. It has no real bass, so what's the point? Starting with a fresh sheet of paper we can do something simple that will not have complex compound angles, not have so many folds, and keep the width of the one bend in the new design so narrow that it can go high enough to meet a 1" driver that can be selected on its VHF response, rather than how well it handles the midrange. This would be the general idea (push-pull to eliminate even-order harmonic distortion, and act like a phase-plug). "I like the Faital pro hf200 on the EV HP640" I'll bet that sounds great. "Outstanding drivers, but AFAIK no longer in production" What do you suggest from EV, now that the EVM DL12X is out-of-production? The EVM 12L Classic is about $100 more than the B&C 12PE32. EVM-12L CLASSIC EVM-12L CLASSIC DJK: can you please explain how you are going to make bass with such a short horn length? I must be missing something here as I am seeing a short path and a small mouth? Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
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