I am looking around for a decent driver to make a 2-way system with the Raven R2. I am looking to put the driver in a straight ML TL, and hoping to get down to an f3 of 30hz. I did some simulations, and the Seas Excel W22EX001 seems to go low and roll off nicely in a decent sized TL:
It appears like it could be crossovered at 2k..
Looking through the scanspeak line, I found that the 7" 18W8531G revelator midwoofer goes pretty low, and all the way up to 5khz. Here is what mathcad simulated it at in a ML TL:
It is a bit more efficient, but is also quite expensive..
I also did a simulation for a pair of Alcone HE 5.25 drivers that I have sitting around, which I got from the DIYATL event:
It seems to go quite low for such a small driver, but I am guessing it will have excursion problems at high volumes.
I ran simulations with quite a few of the Focal drivers, (W models look good, but don't go low enough).
I have considered just making an enclosure for the time being with the Alcone drivers and the R2, as I already have crossover for the R2 at 2khz, and a schematic for a 2khz crossover for the Alcone, but am sure I will definately want to upgrade to a better woofer. I have also considered a 3-way system, with a ML TL for the bass unit.
ML TL enclosure (bracing not shown)
I already have the drivers and have some mdf sheets laying around, so my cost is minimal, in addition to time.
Does anyone have any suggestions, or can point me to similar projects. I saw Herm's project with the smaller revelator driver, but I am looking for lower bass. Any suggestions for a good driver to match with the R2 in a 2-way?
( mathcad simulations done using MJK's mathcad sheets from www.quarter-wave.com )
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Brian
An externally hosted image should be here but it was not working when we last tested it.
It appears like it could be crossovered at 2k..
Looking through the scanspeak line, I found that the 7" 18W8531G revelator midwoofer goes pretty low, and all the way up to 5khz. Here is what mathcad simulated it at in a ML TL:
An externally hosted image should be here but it was not working when we last tested it.
It is a bit more efficient, but is also quite expensive..
I also did a simulation for a pair of Alcone HE 5.25 drivers that I have sitting around, which I got from the DIYATL event:
An externally hosted image should be here but it was not working when we last tested it.
It seems to go quite low for such a small driver, but I am guessing it will have excursion problems at high volumes.
I ran simulations with quite a few of the Focal drivers, (W models look good, but don't go low enough).
I have considered just making an enclosure for the time being with the Alcone drivers and the R2, as I already have crossover for the R2 at 2khz, and a schematic for a 2khz crossover for the Alcone, but am sure I will definately want to upgrade to a better woofer. I have also considered a 3-way system, with a ML TL for the bass unit.
ML TL enclosure (bracing not shown)
I already have the drivers and have some mdf sheets laying around, so my cost is minimal, in addition to time.
Does anyone have any suggestions, or can point me to similar projects. I saw Herm's project with the smaller revelator driver, but I am looking for lower bass. Any suggestions for a good driver to match with the R2 in a 2-way?
( mathcad simulations done using MJK's mathcad sheets from www.quarter-wave.com )
--
Brian
Since you want to cross to the ribbon at at least 2kHz, I'd recommend the Seas Excel W18EX over the W22EX. It might lose a little of the bottom end extension, but it will more than make up for it in the crossover region. Looking at the published response graphs, the 8" woofer has about a 6 dB/octave rolloff starting at 1.5 kHz, immediately followed by a nasty 10+ dB peak caused by the breakup resonance modes. The 7" W18EX has a shallower rolloff of about 2dB in the xo region, and it's peak is at a sligtly higher frequency, narrower, and less jagged. In my opinion, crossover design would be much easier with the W18EX. Also, I'd definitely recommend an MTM configuration because of the extremely high efficiency of the tweeter. I wouldn't want to attenuate such a great driver any more than I have to.
P.S. Brian, maybe you can give me your advice on my driver selection. Get on ICQ if you can.
P.S. Brian, maybe you can give me your advice on my driver selection. Get on ICQ if you can.
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