Damn right Tannoys like their juice!
As a rule of thumb the more clean power you can give them the better they get! That said I was amazed by the transformation after going active.
The only way to describe it is that they now have the clarity and midrange of
Quad ESL's combined with the dynamics and bass (well almost; just wait for the new cabs which will lower the response to 30Hz) of Klipschorns...
The crossover point and slope are not that critical: 800-1000Hz for 15" and
about 1.2k for 12's. Slope either 12dB or 24dB (better but remember to reverse the treble connections! The passive xover slope is 12dB which requires the treble to be wired out of phase.)
You will need the parametric for the notch filter to avoid the dreaded "Tannoy
Honk". This varies slightly across the different drivers but if you look at your passive crossover you'll find a cap, a coil and a resistance strapped across the treble unit. Thats the notch filter; just draw out the slopes created by the components and there is your starting point! Needless to say that a low level
parametric is far more precise then passive high level filtering.
The second eq band is needed because Tannoy tweeters have a response very much like modern constant directivity horns and so require some boost from
5-6kHz to 20k. About 4.5-6 dB/oct..In the end the crossover responses can be dramatically improved and the total absence of coils in the signal path means that the bass tightens up no end! There are bottom end is full of previously unheard detail. It is surprising how many recordings which I thought were badly done with lots of bottom end mush turned out to be really rather good...
Sounds like a lot of processing but the way I see it the same processing happens in the passive crossover and I can take the energy needed to do it from the signal current (passive) or I can leave the signal unmolested and use mains current to do the processing!
Careful shopping on ebay also meant that the whole thing cost me less then a set of top-notch caps... you will need some response measuring kit though for fine tuning.
Lastly a word of warning: Activate your Tannoys and no other speaker will ever do!
As a rule of thumb the more clean power you can give them the better they get! That said I was amazed by the transformation after going active.
The only way to describe it is that they now have the clarity and midrange of
Quad ESL's combined with the dynamics and bass (well almost; just wait for the new cabs which will lower the response to 30Hz) of Klipschorns...
The crossover point and slope are not that critical: 800-1000Hz for 15" and
about 1.2k for 12's. Slope either 12dB or 24dB (better but remember to reverse the treble connections! The passive xover slope is 12dB which requires the treble to be wired out of phase.)
You will need the parametric for the notch filter to avoid the dreaded "Tannoy
Honk". This varies slightly across the different drivers but if you look at your passive crossover you'll find a cap, a coil and a resistance strapped across the treble unit. Thats the notch filter; just draw out the slopes created by the components and there is your starting point! Needless to say that a low level
parametric is far more precise then passive high level filtering.
The second eq band is needed because Tannoy tweeters have a response very much like modern constant directivity horns and so require some boost from
5-6kHz to 20k. About 4.5-6 dB/oct..In the end the crossover responses can be dramatically improved and the total absence of coils in the signal path means that the bass tightens up no end! There are bottom end is full of previously unheard detail. It is surprising how many recordings which I thought were badly done with lots of bottom end mush turned out to be really rather good...
Sounds like a lot of processing but the way I see it the same processing happens in the passive crossover and I can take the energy needed to do it from the signal current (passive) or I can leave the signal unmolested and use mains current to do the processing!
Careful shopping on ebay also meant that the whole thing cost me less then a set of top-notch caps... you will need some response measuring kit though for fine tuning.
Lastly a word of warning: Activate your Tannoys and no other speaker will ever do!