- 59 posts total
- 59 posts total
Hi BDP, Didn't know about the ET dipole, interesting! While they share dipole virtues, the GR Research and Magnepan subs are somewhat different beasts. The GR is bigger -- the Magnepan sub is a 3' tall triangle that's designed to be concealable. I'd say it's also more of a subwoofer, with flat response down to 20 Hz. OTOH, from what I've heard, the Magnepan woofer sounds better where it plays because of the smaller drivers. TANSTAAFL!
Hi Josh, nice to hear from you here. I decided not to respond to @theaudioamp, as he appears to be one of those who knows just enough to be convinced of his lack of ignorance (for instance, everybody knows a dipole does not "load" the room the way a monopole does). Guess he’s never read the writings of Siefried Linkwitz. THAT is a humbling experience ;-) . One of the geniuses of loudspeaker design.
Regarding the smaller drivers used by Magnepan in their dipole sub: Brian Ding was for quite a while offering a Rythmik Audio sub using 8" woofers, but argued that it’s advantage was not simply in "speed" (lots of people think a smaller woofer automatically results in "faster" performance. Yes, lower driver moving mass can produce faster "settling time" in a woofer, but moving mass alone is but one of many factors involved in that issue.), but rather in its ability to play higher in frequency (the GRR/Rythmik OB sub plays up to 300Hz). He offered the 8" sub as a "midbass coupler", emphasizing that his 12" and 15" woofers are just as "fast" as are his 8", but with greater maximum SPL output capability.
By the way, the Magnepan dipole sub is named the Ultra Wideband Bass System because its response extends up into not just the midrange, but even into the treble range! The technically informed reader knows the higher in frequency a driver will play, the greater is its ultimate speed capability potential. Wendell argues that the UBSes high frequency extension is another reason (aside from its dipole performance characteristics) for its ability to blend with planar loudspeakers.
8" is certainly a popular size woofer in hybrid loudspeakers (planars with built in subs). Roger Modjeski used an 8" woofer in his Music Reference ESL loudspeaker, as of course does Bruce Thigpen in his Eminent Technology LFT-8b.
bass frequencies are known to be omni directional, so it has never made sense to me why the dipole sub topic gets significant air play, if in fact the subs are truly producing 100-120 hz output and below - i suppose that for even good subs there is some ’leakage’ above that cutoff, which may be the answer...
dsp, otoh, seems to be very useful, to deal with timing/delay/phase issues, and as per the above, to manage a steeper rolloff/cutoff - computing power is so cheap to build into audio gear now, cellphone control and app-writing is so easily done
that said, with my 3.7i's in my room i do not feel the need for a sub/subs in the least - one day i will hook up my rels and see if i would amend this present belief