I can help shed a little light, maybe... Recently I was at my favorite speaker shop (Nick's Speaker Shop in Boardman, Ohio. Nick was tech at Electric Ladyland Studios and has some really cool speakers and stuff). Sorry, got off topic. OK, so I was over there wanting to rebuild some EV SRO bass speakers and told him I also had some EV 15L's out of a guitar cabinet I was going to use for mids on a PA system I was building. Nick told me he could use the same cones out of the SROs and do either the SROs or the 15Ls and modify to play bass through them. He told me the only difference was that EV milled out the bass speakers another 1/4" to allow the cone to dig deeper in range and get the bass signals. Makes sense to me, because if you look at the low end frequency between a guitar speaker and a bass equivalent in the same speaker family you are only talking very little difference on the bottom end number.
I knew a guy (me) who used SRO guitar speakers and played bass for a long time with them, just couldn't hit lows too hard and played a little trebly, which was OK for how and what volume level I played in those days.
I actually use EVM15L’s with factory cones in a Sunn 215S cab as well as SRO’s in a 2000S cab, both for bass guitar. I also have EMV15B’s, but IMO the L’s are a little more articulate and tighter on the bottom than the B’s and sound better to my ears. I hit the pair of L’s in the 215S pretty hard with a 225 watt Reeves, I’m not
at all shy with the bass knob, and they hold up very well.
I’ve never actually measured the VC gaps, but I’m pretty sure that they
share motor structures, ala the JBL D and K 130/140’s, and the E 130/140’s.
I think the differences in response are probably because of differences in cone and suspension rather than any physical differences in the frame and motor assemblies, but as I said I’ve never measured the gaps in my EV’s. I know that the old JBL’s are the same, the differences between a 130, 130F, and a 140 are in the VC/cone assemblies themselves.
I wonder if it’s possible that the Sunn Transducer is a similar story. Maybe the difference is just the cone assembly, or maybe the only difference is just the sticker themselves?
I know that there are “sticker anomalies” in Sunn cabs; I bought the pictured Sceptre cab from the original owner several years ago, and as you can see the stickers are applied crooked, but
consistently 45 degrees off; not a
little crooked as if possibly someone did it to amuse themselves on a slow day at the factory.
Maybe new member Rex B can shed some light on this, as he was involved in speakers as an electro-acoustic engineer at Sunn, albeit about a decade after the cabs in question.
