Tannoy 3836 (CPA15) ULTIMATE

[blackeye*_0]

I like these drivers as they are very smooth and coherent. They also have impressive response plots, and the crossover (ala DMT15Mk2) has very little in the signal path. Tannoy must have really done their homework on these, as they are awesome. This, mind you, coming from someone who is obsessed with vintage Tannoy (Alnico) and the pepperpot. Still, these drivers amaze me. The problem is every single time I have heard them (including its varients), they leave something desired on low bass.

Even the almighty DMT215 is missing the lowest bass, and this was confirmed by implementing a subwoofer: big improvement. Tannoy's published specs on the big 215DMT is -3db @ 35Hz (inflated?). The 215's cabinet is divided into two subenclosures, and no matter how many times I try modeling the driver in WinISD with that volume I don't get anything near that. However, WinISD's optimized enclosure for a single 3836 is a whopping 518.7L (18.3 cubic feet)! That's a HUGE cabinet. HOWEVER, look at the plot!! It's amazing! Down 3db at 25Hz and nearly ruler flat response.

I have the space to accommodate such a cabinet, and I'm more than willing to build it. Before I make a fool of myself, am I missing something?

[Pallas]

Well, having the space or not, ~50 cubic feet (after wall thickness, bracing, etc.) is a lot of space to be taken up by a pair of speakers.

Also, you're looking at potential output unbounded by xmax. Assuming the 3836 follows the same trend as the Dual Concentrics I have (12 DMT II, 8 NFM II, System 800), the woofer does not have a lot of throw. Maybe 4mm tops, and probably less. So the SPL you will be able to get down low will be tiny, even though the theoretical FR goes very deep.

Also, if you listen to a lot of material with really deep bass, you could get modulation of the treble due to large woofer throws. Tannoy often seem to spec their cabinets to minimize Dual excursion.

A better solution is, IMO, to put the 3836 into a fairly small sealed enclosure. How small depends on how far out you want to put them in the room; the further, the smaller, because you can just the high-Q bump to compensate for lack of wall loader. That should still reach to 80-100 Hz without a problem. Then add three separately powered subs around the room. They can be small, or they can be massive. See the discussions about Geddes-style multisubs elsewhere on this forum. Then you will get Dual Concentric goodness on top, and bass quality to match.

[blackeye*_0]

Originally Posted by Pallas

Well, having the space or not, ~50 cubic feet (after wall thickness, bracing, etc.) is a lot of space to be taken up by a pair of speakers.

Also, you're looking at potential output unbounded by xmax. Assuming the 3836 follows the same trend as the Dual Concentrics I have (12 DMT II, 8 NFM II, System 800), the woofer does not have a lot of throw. Maybe 4mm tops, and probably less. So the SPL you will be able to get down low will be tiny, even though the theoretical FR goes very deep.

Also, if you listen to a lot of material with really deep bass, you could get modulation of the treble due to large woofer throws. Tannoy often seem to spec their cabinets to minimize Dual excursion.

A better solution is, IMO, to put the 3836 into a fairly small sealed enclosure. How small depends on how far out you want to put them in the room; the further, the smaller, because you can just the high-Q bump to compensate for lack of wall loader. That should still reach to 80-100 Hz without a problem. Then add three separately powered subs around the room. They can be small, or they can be massive. See the discussions about Geddes-style multisubs elsewhere on this forum. Then you will get Dual Concentric goodness on top, and bass quality to match.

I was afraid someone would say all that. My 3836's currently reside in a rather small sealed cabinet and are augmented by Tannoy's PS350 sub. It sounds alright, I guess...better than what I heard on the 215DMTmk2, but still I was hoping for something better (with less pieces). For me the whole appeal of a 15" DC is that it can cover the whole musical range (ideally). What I am finding is that my old configuration with 10" DC's works best because they all need a sub (IMO)...and I much prefer the 10 on midrange.

[Pallas]

Well, for starters a multisub setup would be much, much better than the single sub. Regardless of which Duals you use.

But I've come to a similar conclusion about the 15's. Having compared 12 DMT II's, CPA-12's, and 15 DMT II's side-to-side, I felt both 12s were smoother in the midrange and the extra efficiency of the 15 (compared to the DMT's; the CPA-12's were about the same efficiency but have much poorer bass extension) didn't seem like a good tradeoff. By contrast, the 12s give up nothing in any area to the 8's except for size. I've never had a chance to compare the 10's to the 12's, and probably won't just so I stay happy with my 12's.

As for covering the whole range, even if the 3836 had 90mm xmax and no potential modulation issues, it still couldn't cover the whole range. The bass is dominated by the room, not the speaker, and a pair of speakers placed for mids/treble/imaging will be in a crappy place for bass. So the only real high-fidelity approach is to put mains where they do best, and put subs where they do best.

[blackeye*_0]

Originally Posted by Pallas

Well, for starters a multisub setup would be much, much better than the single sub. Regardless of which Duals you use.

But I've come to a similar conclusion about the 15's. Having compared 12 DMT II's, CPA-12's, and 15 DMT II's side-to-side, I felt both 12s were smoother in the midrange and the extra efficiency of the 15 (compared to the DMT's; the CPA-12's were about the same efficiency but have much poorer bass extension) didn't seem like a good tradeoff. By contrast, the 12s give up nothing in any area to the 8's except for size. I've never had a chance to compare the 10's to the 12's, and probably won't just so I stay happy with my 12's.

As for covering the whole range, even if the 3836 had 90mm xmax and no potential modulation issues, it still couldn't cover the whole range. The bass is dominated by the room, not the speaker, and a pair of speakers placed for mids/treble/imaging will be in a crappy place for bass. So the only real high-fidelity approach is to put mains where they do best, and put subs where they do best.

Sounds like you and I have been on similar paths. I recently bought a pair of used Maelstrom 18's, and have yet to do anything with 'em....guess it's time to make some enclosures. I still need a proper LF amp and active crossover.

[Pallas]

Yeah, those'll do some things your PS350 can't.

They'll do just fine in ~20" cubes each. Much more bass than your hypothetical vented 18 cubic foot 3836's!

(I run a single sealed Maelstrom-X in my nearfield system, with three Tannoy 8 NFM II's for LCR and two of the little Tannoy Arena eggs for the side surround channels. One sub is fine in this system because the listening area about which I care is a single stationary more-or-less seat.)

As for active crossover, that's one of the benefits of using a modern receiver instead of old or "high end" gear. Otherwise, look for one of the old Paradigm units. X-30 or something like that. Or a Velodyne SMS-1. I prefer to run my (sealed cabinet) mains fullrange, and just add the subs in with some overlap in the modal region (up to 150 Hz or so). Doing so smoothes out the room response in that region (assuming you can measure and set everything up properly) and IMO makes the room sound "larger" than with the mains highpassed and the subs filling in under them. If you do that, you could get away with just buying a Crown XTi-series pro amp for the Maelstroms, because they have a really useful crossover/parametric-EQ/shelf-filter DSP built in.

[pianomanjdp]

Hello,
I apprecciate this site and all the info you bring to light. Question is> I have a pair of Tannoy NFM-8s and there are 3 posts on the back of each speaker. When I first hooked them up I got the phase wrong and after I switched one of the wires, wow what a difference. But I wondered if I have them hooked up properly with just red and black? Where does yellow come into play?
Am I missing something by not using the third post?
Thanks for your help