For over 20 years I have had a stereo pair of Peerless SWR 308 / 830500 drivers, each in a 97 liter bass reflex enclosure tuned to 19 Hz. These have proved to be as perfect as I could have hoped for, but unfortunately these have been discontinued as well as Peerless XLS-12.
Considering a similar setup, with a less than 100 liters reflex box tuned to 19 Hz, which of the current subwoofers would give the highest SPL [dB]/W/m, with a quite flat amplitude response, between 20 to 30 Hz? *)
Quickly simulating on-line with www.micka.de ( Vb = 97 l, dia = 10 cm, len = 59.7 cm, Ql = 5, temp = 20*C ) could find at least the following:
Discontinued:
Peerless SWR 308 / 830500 ~82.0 dB/W/m, Xmax 12.5 mm
Peerless XLS-12 / P830500 ~82.0 dB/W/m, Xmax 12.5 mm
Current:
Dayton Audio RSS315HO-44 ~81.5 dB/W/m, Xmax 14.0 mm
FAITAL PRO 12HP1060 ~80.5 db/W/m, Xmax 12.0 mm
SB Acoustics SB34SWPL76-4 ~82.0 dB/W/m, Xmax 15.0 mm
Scan-Speak 23W/4557T00 ~81.5 dB/W/m, Xmax 13.0 mm
Scan-Speak 28W/4878T00 ~81.5 dB/W/m, Xmax 14.0 mm
From these, the SB Acoustics driver looks the most interesting on paper. But, an advice or sharing your good experiences with these or other reasonable drivers would be much appreciated.
EDIT: *) Due the appearance of a frequency response plot, term Extended Bass Shelf (EBS) alignment has been sometimes used.
Considering a similar setup, with a less than 100 liters reflex box tuned to 19 Hz, which of the current subwoofers would give the highest SPL [dB]/W/m, with a quite flat amplitude response, between 20 to 30 Hz? *)
Quickly simulating on-line with www.micka.de ( Vb = 97 l, dia = 10 cm, len = 59.7 cm, Ql = 5, temp = 20*C ) could find at least the following:
Discontinued:
Peerless SWR 308 / 830500 ~82.0 dB/W/m, Xmax 12.5 mm
Peerless XLS-12 / P830500 ~82.0 dB/W/m, Xmax 12.5 mm
Current:
Dayton Audio RSS315HO-44 ~81.5 dB/W/m, Xmax 14.0 mm
FAITAL PRO 12HP1060 ~80.5 db/W/m, Xmax 12.0 mm
SB Acoustics SB34SWPL76-4 ~82.0 dB/W/m, Xmax 15.0 mm
Scan-Speak 23W/4557T00 ~81.5 dB/W/m, Xmax 13.0 mm
Scan-Speak 28W/4878T00 ~81.5 dB/W/m, Xmax 14.0 mm
From these, the SB Acoustics driver looks the most interesting on paper. But, an advice or sharing your good experiences with these or other reasonable drivers would be much appreciated.
EDIT: *) Due the appearance of a frequency response plot, term Extended Bass Shelf (EBS) alignment has been sometimes used.
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No experience with these, just want to note that isobaric loaded opens up your driver choices.
GM
GM
A 10 cm port diameter will result in an air velocity of 30 m/s at 20 Hz, which will chuff.
Tool for calculating minimum port diameter at a given air velocity:
Flare-it - Free Speaker Design Software
Tool for calculating minimum port diameter at a given air velocity:
Flare-it - Free Speaker Design Software
Well, it might chuff, depending on the program material. Full-power sine tone at the tuning frequency? Probably. Anything else? Maybe, maybe not.
FWIW, I've been routinely impressed with Faital Pro's offerings. The 15" version of that driver is excellent.
Chris
FWIW, I've been routinely impressed with Faital Pro's offerings. The 15" version of that driver is excellent.
Chris
Thanks for your comments. The port diameter could be larger from the velocity point of view. The length would become an issue in a 100 liter enclosure, if not using bends, etc. The 10 cm was a compromise, resulting almost 70 cm internal height to fit in the vertical pipe. To mitigate unwanted noises the pipe was radiused at the both ends.With program material no issues, at least for me. This could be also due the low tuning frequency.
Thanks Harry, that Dayton driver looks serious. I was able to find the data sheet for "UM12-22 12" Ultimax DVC Subwoofer 2 ohm Per Coil". An issue with the specs is the high Qts of 0.59. For a closed enclosure this could be a killer.
Thanks for pointing out Scan-Speak. E.g. the 23W/4557T00 driver looks very interesting in initial simulations, with a flat amplitude response. The tuning frequency could be even lowered under 19Hz or enclosure volume reduced.
NE315W-04 and Scan-Speak 13-inch drivers have Vas spec a bit too high. There was a comment from GM about isobaric configurations, which might do the trick with these.