Mmmmmm I've read a little on the distributed multiple sub setup. If I remember correctly instead of just exciting room modes from the two speaker locations the spread of subs does it at multiple random locations. Therefore no one mode dominates. Is that correct?
Questions:
1) Has anyone actually tried it?
2)Will this work from 150-200hz downwards?
3)Are the subs run in stereo or mono? I guess right subs run the right channel etc so I'll need an even number of subs
4) Moat subs are on the floor. Would it be beneficial to have at least one raised up to excite even more room modes?
Toole’s book has a lot of info on the subject (subs used in mono below 80 Hz with separate level/phase settings for each woofer), but if you google "floyd toole subwoofer placement” you get lots of hits. One paper that look sparticularily interesting is http://www.bodziosoftware.com.au/article_7.pdf. It talks about woofers in non-rectangular rooms, but then few have actual rectangular rooms once you include windows, doors, or other openings.
dave
Are ther issues with c2c spacing if I went with an 18in driver?
As long as c-c is within a ¼ wl of the XO the drivers are essentially coincident.
dave
Just found this lust worthy offering from Precision Devices
A decent price for a good 18”. Doing a sim similar to that used for the 2 12”, these don’t go duite as low but move almost 2½ x as much air.. 2 would fit into 120 litres (1st pass).
dave
Cheers for your thoughtful responses Dave!
It really looks like a single big driver each side is best. Although...
My interest has been piqued by your push push dual opposed design. Id much rather have swift light bass that misses the lower notes than thunderously low bass that sounds bloated. With 2x12in drivers (better than my previous choices) you have roughly the same Sd as a single 18in(?)
Is the dual opposed push push the better choice? The speakers will be on the short side of the room, are there sidewall boundary issues?
It really looks like a single big driver each side is best. Although...
My interest has been piqued by your push push dual opposed design. Id much rather have swift light bass that misses the lower notes than thunderously low bass that sounds bloated. With 2x12in drivers (better than my previous choices) you have roughly the same Sd as a single 18in(?)
Is the dual opposed push push the better choice? The speakers will be on the short side of the room, are there sidewall boundary issues?
I always prefer to use 2 woofers push-push especially as you go lower. The active reactive force cancelation really helps in taking the box out of the equation. The 2 x SDX10 boxes were built with 15mm ply (well braced). The cabinet could be picked up with one hand, with drivers it was a 2-man lift if you needed to go anywhere awkward (like up & down stairs), They were sealed & produced REALLy good, fairly deep bass — and being sealed can trade off excursion for even lower bass using EQ. SDX10 is currently unavailable so i have been looking at other 10”. There are a couple SB 10” that look interesting.
If you don’t need to go really low, the BMS look to be a good choice, they go in a fairly small box, and if you have sufficient room-gain or active EQ could be tuned lower (if EQ at the expense of ultimate loudness).
There are almost literally a zillion bass drivers to look at each with there own set of compromises.
At low frequencies, the bass is essentially omindirectional so how the drivers fire is immaterial unless they are close enuff to a boundary to be slot loaded. That can be an advantage or a disadvantage. Woofers near a boundary will get more room gain and will typically be better at exciting room modes (so more need of at least 2 woofers).
Personally 2 stereo push-push woofers is my preference juggling ability to minimize room issues, size issues, complication issues (a consequence of lots of woofers), etc.
dave
If you don’t need to go really low, the BMS look to be a good choice, they go in a fairly small box, and if you have sufficient room-gain or active EQ could be tuned lower (if EQ at the expense of ultimate loudness).
There are almost literally a zillion bass drivers to look at each with there own set of compromises.
At low frequencies, the bass is essentially omindirectional so how the drivers fire is immaterial unless they are close enuff to a boundary to be slot loaded. That can be an advantage or a disadvantage. Woofers near a boundary will get more room gain and will typically be better at exciting room modes (so more need of at least 2 woofers).
Personally 2 stereo push-push woofers is my preference juggling ability to minimize room issues, size issues, complication issues (a consequence of lots of woofers), etc.
dave
.... So, logically a horn would be best? I would like to try one for clean low bass .....
FYI, one suggestion:
Tray EV Patrician IV with 18" driver EVM18B .... It's concept is a oversized Klipschorn.
Karel (home made full horn addicted since '68)
The 18sound XT1464 does sound better than the Faital 142.
In what respect ? Over the whole bandwidth or is it just at the lower end ? How are you using yours ?
I ask because I will probably also build a smaller version of my big MTMs that I will cross over a little higher than the current one. I currently cross my HF146/XT1464 at 650 Hz and it works without problems even at loudness levels that can be called insane in a domestic situation.
The smaller one would be crossed around 800 Hz most probably. If the sonic differences between the Faital and the 18 Sound waveguides are limited to their lower end this would be fine with me. Otherwise I would also use the XT1464 for the small box.
Regards
Charles
Nice to know the HF drivers from Faital Pro can be used so low!
Now it's really a choice between:
2x http://www.bmsspeakers.com/fileadmi...1/cones_ferrite/bms_12s330_2011-04_woofer.pdf per side in a suitably large box to make use of the 29hz fs. Drivers will be braced against each other and there'll be decent bracing also. Not sure on sealed or vented as I'm without the ability to run winisd at the moment.
Or
1x per side http://www.faitalpro.com/en/products/LF_Loudspeakers/product_details/datasheet.php?id=151070100 or http://precision-devices.com/file-downloads/PD.184C01Datasheet270715.pdf in a sand filled and braced cabinet. Pano tells me the best bass he has heard was in a sand filled cab so that's a laudable goal.
Dave, whose opinion I respect very much, has laid his preference on the dual 12.
Any others will to throw their hat into the ring?
Now it's really a choice between:
2x http://www.bmsspeakers.com/fileadmi...1/cones_ferrite/bms_12s330_2011-04_woofer.pdf per side in a suitably large box to make use of the 29hz fs. Drivers will be braced against each other and there'll be decent bracing also. Not sure on sealed or vented as I'm without the ability to run winisd at the moment.
Or
1x per side http://www.faitalpro.com/en/products/LF_Loudspeakers/product_details/datasheet.php?id=151070100 or http://precision-devices.com/file-downloads/PD.184C01Datasheet270715.pdf in a sand filled and braced cabinet. Pano tells me the best bass he has heard was in a sand filled cab so that's a laudable goal.
Dave, whose opinion I respect very much, has laid his preference on the dual 12.
Any others will to throw their hat into the ring?
Just bear in mind that the BMS 12S330 is a dedicated woofer (subwoofer in PA parlance) and as per manufacturer data is not useful above 300Hz.
Unlike manufacturers data there is no way it produces 96dB/1W across its usable bandwidth. 89-91 is much more feasible.
When I simmed it it seemed unusable in a sealed box which is what I would expect from its low (0.24) Qts.
Unlike manufacturers data there is no way it produces 96dB/1W across its usable bandwidth. 89-91 is much more feasible.
When I simmed it it seemed unusable in a sealed box which is what I would expect from its low (0.24) Qts.
If you're going for a three way system I would also strongly suggest a 1" HF driver. Faital makes nice 1" drivers as well.
Interesting cheers : Looks like they might goes louder higher up and potentially smoother. Is that the reason for your recommendation?
Just bear in mind that the BMS 12S330 is a dedicated woofer (subwoofer in PA parlance) and as per manufacturer data is not useful above 300Hz.
Unlike manufacturers data there is no way it produces 96dB/1W across its usable bandwidth. 89-91 is much more feasible.
When I simmed it it seemed unusable in a sealed box which is what I would expect from its low (0.24) Qts.
That is very helpful!!!! I was trying to figure out what the catch was with the BMS drivers.
Only being usable below 300hz shouldn't be an issue. The expected 89-91db could be overcome with amp power and creative dsp. However pumping in more power means more distortion even when playing at lower levels.
The hunt for a better 12in continues
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This one is an informal measurement of the Faital HF10AK on an Eighteensounf XT1086 Horn:
2-Way DiY Hifi speakers eighteensound
Let me see whether I can find a measurement of the HF146. Fro me the HF 146 climb up high enough but I am am not in my twenties anymore. So for someone else or for showing off an 1" driver might be better in case of a three way.
Regards
Charles
2-Way DiY Hifi speakers eighteensound
Let me see whether I can find a measurement of the HF146. Fro me the HF 146 climb up high enough but I am am not in my twenties anymore. So for someone else or for showing off an 1" driver might be better in case of a three way.
Regards
Charles
If you speak french here is a fairly comprehensive test of three 12" drivers:
Comparatif 12 pouces Pro : BMS 12S305 – Beyma 12G40 – 18’s 12LW1400 - JustDIYIt !
I wish I'd speak french...
Comparatif 12 pouces Pro : BMS 12S305 – Beyma 12G40 – 18’s 12LW1400 - JustDIYIt !
I wish I'd speak french...
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