PRV, a Brazillian Pro Audio driver company makes nice PA drivers, and I recently found out about an interesting offering from their "Woofer" line. The 5MR450-NDY is woofer that may interest some of you as a possible high sensitivity wideband unit. It is labeled a woofer but the spec sheet clearly shows promise as a fullrange driver with highs extending into the 15kHz range. There are two variants: 8-ohm, 0.57 Qts at 95dB and 4ohm, 0.42 Qts at 98dB sensitivity at 2.83 volts-1-meter. Certainly this is not the first 95-98dB wideband driver, but I don't know of another rated for 250 watts RMS with 2 mm of xmax - if you do the math, the max SPL from this driver is pretty high up there and earns this driver, the moniker of "El Rey" for FAST. There is a limitation of course, it cannot produce bass below 200 Hz and as such, needs a helper woofer or sub, hence I qualify it as a driver for a FAST (fullrange assisted subwoofer technology, i.e., 2-way with a low XO) configuration because the fs is about 170Hz to 180Hz. But, this frequency range is about an ideal XO point for a FAST system. If you have an interest in having a fullrange top driver that can light up a room keep reading.
8-ohm variant:
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4-ohm variant:
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I received the 8-ohm variant drivers the other day (about $105 ea - yeah, I know, I can buy 10 Vifa TC9FD's for one of these... btw, the front view looks just like an oversized TC9FD, down to the front foam gasket and rounded off square frame 🙂 ) and they look solidly built with a nice cast aluminum frame, solid thick paper cone, and a bevy of radially mounted Nd magnet slugs, and a vented pole piece for good cooling. The suspension and cone are very STIFF to achieve the high fs and high efficiency - I could barely get it to flex with finger pressure. There is no whizzer cone, just a stiff hemispherical domed dustcap - which I believe is why this thing works so well at HF's - it acts like a dome tweeter.
I proceeded to mount it to my cardboard test OB "Cheap and FAST, Literally" setup after making a new foam core adapter plate. Here is a photo of the setup. The driver is offset so that the center is 5 inches from the side and 5.5 inches from the top in a 12 in wide open baffle with small wings on the back. I hooked it up with the mic on axis at 1 meter away and took this measurement:
Here is the factory frequency response data:
I was really shocked by how good this measurement looks, and I think that you will agree that may even be smoother than many a more expensive 95dB class full range drivers out there with names starting with an L or F. None of them will match it in SPL capability. Many folks will be perfectly happy with 15kHz highs, and a helper super-tweeter can always be added for more "air". The bass starts falling off at 340 Hz here, and that is consistent with a 12 in wide baffle with a one inch offset mount.
For a simple yet high SPL capability, high passing at about 230 Hz (in a 6 liter sealed box) lets you put into it a solid 200 watts RMS for 113dB SPL (xmax limited), and still stay below the 250 watt thermal rating. If you front-horn loaded it, you can get some amazing SPL's in the 120+ dB range. Here is the prediction of the SPL in a 6 liter sealed box (Q=0.707) with 35 volts rms of drive:
I did not have time to set it up in a FAST with a woofer yet, but did manage to listen to some test tracks where I knew what the sound should be like above 300 Hz. It sounds very nice and articulate, smooth, and an amazing level of detail and sparkle from heavy paper coned PA woofer. Snare drums, high hats, clicks, drum rim shots, all were present and sounded good.
If you want extension down to 100 Hz to pair with a traditional non-directional "sub-woofer", alignments like a bass reflex, MLTL, even BLH can be employed and they have the advantage of being rather small as only 100 Hz bass extension is needed.
I will add more predictions in other alignments and if anyone else has some experience with this driver, please let me know how you like it.
Edit: this driver can be used in a 300Hz to 15kHz tractrix horn too. Here is the response and harmonic distortion (which is very low).
Here is the horn:
Edit July 24, 2021: Recent detailed measurements in Hypercube here:
PRV 5MR450-NDY for FAST/WAW applications
8-ohm variant:
Page not found
4-ohm variant:
Page not found
I received the 8-ohm variant drivers the other day (about $105 ea - yeah, I know, I can buy 10 Vifa TC9FD's for one of these... btw, the front view looks just like an oversized TC9FD, down to the front foam gasket and rounded off square frame 🙂 ) and they look solidly built with a nice cast aluminum frame, solid thick paper cone, and a bevy of radially mounted Nd magnet slugs, and a vented pole piece for good cooling. The suspension and cone are very STIFF to achieve the high fs and high efficiency - I could barely get it to flex with finger pressure. There is no whizzer cone, just a stiff hemispherical domed dustcap - which I believe is why this thing works so well at HF's - it acts like a dome tweeter.

I proceeded to mount it to my cardboard test OB "Cheap and FAST, Literally" setup after making a new foam core adapter plate. Here is a photo of the setup. The driver is offset so that the center is 5 inches from the side and 5.5 inches from the top in a 12 in wide open baffle with small wings on the back. I hooked it up with the mic on axis at 1 meter away and took this measurement:

Here is the factory frequency response data:

I was really shocked by how good this measurement looks, and I think that you will agree that may even be smoother than many a more expensive 95dB class full range drivers out there with names starting with an L or F. None of them will match it in SPL capability. Many folks will be perfectly happy with 15kHz highs, and a helper super-tweeter can always be added for more "air". The bass starts falling off at 340 Hz here, and that is consistent with a 12 in wide baffle with a one inch offset mount.
For a simple yet high SPL capability, high passing at about 230 Hz (in a 6 liter sealed box) lets you put into it a solid 200 watts RMS for 113dB SPL (xmax limited), and still stay below the 250 watt thermal rating. If you front-horn loaded it, you can get some amazing SPL's in the 120+ dB range. Here is the prediction of the SPL in a 6 liter sealed box (Q=0.707) with 35 volts rms of drive:

I did not have time to set it up in a FAST with a woofer yet, but did manage to listen to some test tracks where I knew what the sound should be like above 300 Hz. It sounds very nice and articulate, smooth, and an amazing level of detail and sparkle from heavy paper coned PA woofer. Snare drums, high hats, clicks, drum rim shots, all were present and sounded good.
If you want extension down to 100 Hz to pair with a traditional non-directional "sub-woofer", alignments like a bass reflex, MLTL, even BLH can be employed and they have the advantage of being rather small as only 100 Hz bass extension is needed.
I will add more predictions in other alignments and if anyone else has some experience with this driver, please let me know how you like it.
Edit: this driver can be used in a 300Hz to 15kHz tractrix horn too. Here is the response and harmonic distortion (which is very low).

Here is the horn:

Edit July 24, 2021: Recent detailed measurements in Hypercube here:
PRV 5MR450-NDY for FAST/WAW applications
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