Suitable 18" or 21" Bass Drivers to construct a W or H stereo pair of subwoofers.
I am looking for suitable 18" or even 21" drivers to construct a W or H stereo pair of subwoofers. I will use this plate amp to power them. This amp has some ability to EQ the lower bass response.
I am interested in the AE 18" woofers, but first want to consider what suitable units which are available to me in the UK first. Use will be in a large room to partner a Quad Electrostatic, why you may ask such a large driver? well it is to get as close to 20Hz in room performance as possible.
I am looking for suitable 18" or even 21" drivers to construct a W or H stereo pair of subwoofers. I will use this plate amp to power them. This amp has some ability to EQ the lower bass response.
I am interested in the AE 18" woofers, but first want to consider what suitable units which are available to me in the UK first. Use will be in a large room to partner a Quad Electrostatic, why you may ask such a large driver? well it is to get as close to 20Hz in room performance as possible.
So you're talking about OB setups I presume.
Is there any particular reason you do not want to consider 15" drivers? You list W as a possible baffle setup, which is good since it offers some benefits for vibration cancellation, 2 x 15" would fit very well, be much cheaper, and have just about the same SD as a single 21".
There is a large number of very reasonably priced drivers suited for your needs, is there any particular reason you want to use expensive drivers?
You intending to use the woofers with some Quad's, I assume you are not going to host concerts with several hundred participants using this setup.
Is there any particular reason you do not want to consider 15" drivers? You list W as a possible baffle setup, which is good since it offers some benefits for vibration cancellation, 2 x 15" would fit very well, be much cheaper, and have just about the same SD as a single 21".
There is a large number of very reasonably priced drivers suited for your needs, is there any particular reason you want to use expensive drivers?
You intending to use the woofers with some Quad's, I assume you are not going to host concerts with several hundred participants using this setup.
I suggest you add a processor with a parametric equalizer. Even with dipole woofers, the room dominates the frequency response and this usually will not be flat. With suitable EQ you can remove most of its effect, at least for one listening location. A subsonic filter will also be handy to protect the woofers. Affordable solutions are among others a MiniDSP 2x4 or a Behringer Inuke 3000 DSP (beware of the noisy fan).
I use PRECISION DEVICES PD.2150 21” 1000 WATT Loudspeaker 8ohm for my drivers.
If you are using this setup in an enclosed space, use just ONE or if you must have TWO place them together anywhere in the room to avoid audio cancelling or holes in the bass as you walk around. Human ears cannot determine where sub sound comes from, so in a corner, out of the way is ideal. Your selected speakers are only 92.8dB/metre, whereas the 21" is much more sensitive at 98dB/metre. Less power required for more sound.
If you are using this setup in an enclosed space, use just ONE or if you must have TWO place them together anywhere in the room to avoid audio cancelling or holes in the bass as you walk around. Human ears cannot determine where sub sound comes from, so in a corner, out of the way is ideal. Your selected speakers are only 92.8dB/metre, whereas the 21" is much more sensitive at 98dB/metre. Less power required for more sound.
Open to suggestions as to which 15 might be worth investigating (UK availability)
21'' is usually used in front of a stage on a rock concert. I remember seeing 6 JBL Vortex cabs at each side of the stage. That is 6+6 *2200W* (2 speakers per cab). Do You pretend rockin' the house ? For home I would use 12'' or 15'' drivers. Usually Higher sensitivity than 21'' monsters. Believe me 1000W 100dB speakers is loud deafning enough.
Guys, hes doing Open Baffle dipole bass to match his classic Quad ESL dipole so an 18" is well indicated.
The AE Dipole 18 is going to be hard to beat. Is there anything else that comes close for delivering OB bass SPL? Its designed specifically for that and I couldnt find a better value driver for modelled OB dB output. Model with eg Basta Tolvan Data
You might find the AE Dipole 18" provides more OB dB with less watts and less cost then even the 21" PRECISION DEVICES PD.2150
One AE Dipole 18 in an H-frame under a stereo pair of eg Quad 57 should be sufficient to generate good levels of most acoustic instrument bass reproduction in most rooms and free the ESL to produce much higher SPL through the mid range. Allow a slot between the H-frame and the ESL and mount the ESL panel exactly in the plane of the woofer so the ESL membrane is in the dipole null of the woofer. Will the plate amp equaliser provide sufficient low end boost or the upper extension the AE dipole18 can give? The suggestion of a Behringer Inuke 3000 DSP with a fan mod is smart.
The AE Dipole 18 is going to be hard to beat. Is there anything else that comes close for delivering OB bass SPL? Its designed specifically for that and I couldnt find a better value driver for modelled OB dB output. Model with eg Basta Tolvan Data
You might find the AE Dipole 18" provides more OB dB with less watts and less cost then even the 21" PRECISION DEVICES PD.2150
One AE Dipole 18 in an H-frame under a stereo pair of eg Quad 57 should be sufficient to generate good levels of most acoustic instrument bass reproduction in most rooms and free the ESL to produce much higher SPL through the mid range. Allow a slot between the H-frame and the ESL and mount the ESL panel exactly in the plane of the woofer so the ESL membrane is in the dipole null of the woofer. Will the plate amp equaliser provide sufficient low end boost or the upper extension the AE dipole18 can give? The suggestion of a Behringer Inuke 3000 DSP with a fan mod is smart.
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If you're using an amp such as the inuke 3000 with dsp, then it almost does not matter, as long as the fs is lower than 35hz and xmax over 6mm (with either double 15" or single 21"). Maybe go for cast frame units.
JonSnell mentioned the Precicion Devices PD.2150, but the Beyma 21PW1400Fe is probably just as good, and 200£ cheaper. RCF LF21X451 is also reasonably priced.
Looking at 15" (for double 15") there's the Eminence Omega Pro 15, the Beyma SM115/N is quite cheap at 100£ each, Faital Pro 15PR400 has a lower than 6mm xmax but it's a good driver and should provide more than enough sound, Faital Pro 15FH510 is a few £ more a bit low qts but has over 9mm xmax just to name a few. There's a ton of suitable drivers to be had
That Faital Pro 18XL1800 is one hell of an impressive spec'ed driver with an Xmax over 20mm. At first gance it looks great for an OB woofer to throw all that air around. But it might suffer in an OB as it looks designed for a box? If anyone models it using Basta versus the Dipole 18 it might not perform any better way down while needing big watts. Basta is free software and when I modelled similar drivers it was educational. If someone models them can they post up the dB vs Hz graphs with watts please?
Another issue with expecting woofers designed for boxes to perform in free air is the openness of the cage. The Faital Pro 18XL1800 back looks a bit closed in for free air flow and may chuff in an OB with turbulence.
An externally hosted image should be here but it was not working when we last tested it.
I dont have shares in Acoustic Elegance but for OB bass where's the serious alternative?
I own one of these (so far) awesome drivers. The basket is very open. See pics on the web, the 2D MFG drawing is not clear about this.
It's not best used in an OB (open baffle, e.g. planar). I didn't suggest that. I strongly suggest loading the driver in a 24" deep H-frame. The TS parameters will be effected in a good way by doing so.
No idea on the 21"...
Accurately modeling the H-frame well is not super easy except with perhaps a horn response program or those MJK programs that are no longer available. I can get a general idea what to expect from back-of-the envelope calculations, and then I build and measure near field responses. Then I use my ACD program to combine front and back nearfield responses plus delay that accounts for the pathlength difference of the H-frame.
Accurately modeling the H-frame well is not super easy except with perhaps a horn response program or those MJK programs that are no longer available. I can get a general idea what to expect from back-of-the envelope calculations, and then I build and measure near field responses. Then I use my ACD program to combine front and back nearfield responses plus delay that accounts for the pathlength difference of the H-frame.
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