Tannoy system 15 DMT II

Hi

Has anyone come across this large efficient studio monitor. What amplification worked best?

 

With a 98db....you could get one of the little flea type amps to run it ....800b's etc


But its not one I've come across.

 

Actually, the quoted 98 db/w sensitivity may be a typo. I read somewhere that Tannoy confirmed they are only 95. The 15 inch driver is the 3833GG, the same as used in the domestic (and vastly more expensive) Tannoy Churchill!

You would expect such a driver to work pretty well with SET tube amplification just like other big Tannoys- but I've seen it mentioned on other forums that the 15DMT's were designed by Tannoy to ideally be used with big bruiser solid state gear to really control the bass. These seems strange because you'd think a speaker this efficient wouldn't need massive watts to excel. However, the 3833 driver's impedance curve may not be quite as amp friendly as some other modern tannoys (such as the Yorkminsters). The impedance graph is illustated in the link below but it's dificult to understand.

I'm interested in buying the 15 DMT's to be used near/midfield in a room smaller than one would normally use speakers of this size (although currently able to run Ardens- just). The DMT's roll off quite high in the bass (not much below 50hz) so I'd use them with my existing REL sub- making for a killier sub / 'sat' system.

Trouble is, if the DMT's aren't BRILLIANT with SET amps (or at the very least PPull), then they are not the speakers for me.


http://www.hilberink.nl/codehans/tannoy29.htm

 

If thats the case ......I'd agree with you

 

Thorsten used to use a pair (3dsonics).

From experiences with 15" tannoys, I'd imagine you'd be fine with 30w push pull +

 

It would be interesting to hear Thorston's experience.

Apparently, upgrading the DMT 15 crossover resistors and caps can be beneficial- as well as using a notch filter for the tweeter. 300B amps are meant to work well- especially if you biamp the speakers (Using parallel single ended would mean 8 x 300B's:yikes. Or perhaps you could use a SET 45 amp for the tweeters? :JPS:

 

It has been known for the Japanese to strip out the crossovers and run active, using a tube crossover and a combination of SET's and OTL's.

Now that would be fun.

 

Hi

Yes, I heard the DMT's are very popular in Japan- especially the bigger 215 DMT with their second driver and slight increase in efficiency. But they're too big for my space for sure and I reckon the 15 DMT is sort of more inert anyway. Would be interested to find about more about using something like a Marchand active xover.

 

Or even 30 watts SET (845).

 

My system is built around these speakers. Speakers are sensitive and can take a lot of power. Dynamic contrasts, prat, detail, transparence, imaging are outstanding. Bass is deliberately light to use in small studios without acoustic overpowering and to give flat bass responce by means of active equalisation(it's for studios not for home!). It's the reason for enormous power reserve-your amps are always out of steam before the speakers.
You need a lot of current to control these 15" monsters in bass.
I use monster zero-feedback 50w KT88 push-pull monoblocks (which where built by my friend) and bass is absolutely wonderful.
If you want SET's I recommend biamping: SET for highs and PP or SS for lows. I added notch filter and built external crossover with Jensens - but stock cross is good enough too. And I agmented speakers with REL subs too and synergy is very good IMO(but no,
subs don't help in bass if your main amp is not capable of current delivery). And last - these speakers show all deficiencies up the chain - good thing for me.

 

Folks,

The 15 DMT is 98db/2.83V in halvespace, that would be soffit mounted into a wall in a studio.

In freefield condition the rating is 95db/2.83V.

What I used was a pair of Monitor Red 15 in corner York's, not the more modern stuff.



These I measured as 95db/2.83V/1m in room, but being 15 Ohm speakers they come in at 98db/1W/1m.

So a reasonable similarity in efficiency exists.

I found that a 300B Amplifier would be needed to get the best from the Tannoys, however, I was running the 300B at a fairly low power operating point, around 6 Watt output most of the time. I suspect a 2A3 Amplifier might work, 45's I found too low in power. Also, I found that mismatching the speaker to a lower impedance tap on the output transformer helped giving a more controlled LF range.

More comments here:

http://www.arduman.com/aa/Sayfalar/thorsten/thorsten.htm

Ciao T

 

Thanks for all the info. Point taken about subs not being a substitute for amps lacking in current. However, couldn't one use something like a Velodyne's built in automatic equalization to get a flat frequency response cutting below 80 hertz. This would put less strain on the amp- meaning less necessity for a powerful one?

 

That's a common misunderstanding - the main energy found in most music is in the band between 100hz and 400hz, and a subwoofer will not come to the rescue there.

 

SM I think you are probably right, but energy and power are two different things. As you probably know, if you put the same amount of power in from 100Hz-200Hz as you do from 200Hz-400Hz, you will get more energy from the 200Hz-400Hz bandwidth.

Secondly, you have to remember that drivers become grossly less efficient as the frequency lowers, so you need more power the lower you go to get the same energy out.

However, more power is always good for control. I would heed Thorsten’s comment about matching the woofer to a lower impedance output tap for tighter bass, if indeed you don't use a sub.

I suppose mmhi-fi may have found he still needed a pretty powerful amp even with a sub because most of what we 'hear' as bass is above 100Hz. This is where the 'pop' of a kick-drum is and all transients which give 'attack' are by nature, quite high in frequency, so good control is still needed for 'quick' sounding bass.

 

Look, I have pair of REL Storms 10 years - I used them with my previous speakers too and in 2 different rooms so I have some experience. My conclusion: you have no chance to integrate them successfully if your main speakers are uncapable at least to 50hz
and amp isn't up to the task. I suspect this rule is right not only for Storms. And of course I used standard speaker-level sub connection in parallel with speaker running full-range. Here the power reserves of 15DMT are very important.

 

Personally, I think this is more to do with the the fact that RELs are not very good. Using a pair of higher quality subs with digital EQ and there should be no problem crossing over at higher frequencies.

 

Surely only the case if you are using EQ, otherwise the drive unit will simply roll off naturally?

If you want a test, listen to the output of a subwoofer only, crossed over at say 50hz. This will give you an idea of how little acoustic output is actually there in the bottom octave and a half on most music.

Sure if you EQ a Subwoofer to provide extension below resonance, the power requirements become disproportional. Hence the large BASH amps in small sealed subs. By contrast, my larger vented JBL's will happily offer 94db efficiency and an easy 8 ohm load at 30hz.

 

There is no chance I will include such thing in signal path. Not in my system. Keep it simple and analogue.

 

MM,

Sorry to say, but you really are missing out. Why do you feel like that out of interest, especially as you are not using a high pass as far as I can tell?

 

I know you use such device but I have absolutely no interest in equalizers and especially digital. My system sounds very satisfactory to my ears without them, my subs integrated beautifully and room problems I effectively solved by help of other means. From my experience the less such devices in signal path the less trouble. And digital... After heroic efforts I put in this area to get any musical results from media I amn't going to add another bomb.