TLs for Tannoys?

[dnsey]

I have a pair of Tannoy 10" Monitor Golds in their standard IIILZ cabs.
The drivers are wonderful, but are severely compromised by the small IB cabinets. In particular, the bass extension is poor, and the midrange 'boxy'.
Having once owned a pair of big IMFs, I'm a big fan of transmission lines.
Would the Tannoys suit TLs? Anyone tried them?
Suggestions please!
Cheers,
Dave.

[GM]

Got ~accurate T/S specs?

GM

[Ouroboros]

Are T-S specs much help for TL design? If you 've got the length of the line right for the Fs of the speaker in the line, how much do changes in Vas or Qt affect the performance?

[GM]

It can be considerable since the length/cross sectional area is critical to getting optimum performance, i.e. max acoustic gain at minimum 'ripple' in the FR with the least amount of stuffing. To use an extreme example, one I did recently required a 48.54Hz 1/4WL pipe to damp down the huge midbass 'hump' of an 83Hz Fs/~2.45 Qts driver. If it had been tuned to 83Hz, the 'hump' would still be there and have a wider BW, with the attendant greater 'ripple' higher up to boot.

GM

[dnsey]

Thanks guys,
These were madwe long before T&S pubished!
There are very sketchy figures available, but not enough to be much use.
[URL=http://www.thielesmall.com/include/details.asp?ID=4972&dtype=1]
I could, of course, measure them, but haven't done so yet.

[GM]

I found these: http://www.hilberink.nl/codehans/tannoy38.htm

Assuming they are ~accurate, the low Qts means a very rolled off response beginning around 500Hz unless significant series resistance is added from a high output impedance tube amp and/or external resistor and/or high DCR inductor.

For instance, if we double Re then we could get a ~T/S max flat down to 30Hz in ~8.09ft^3/25Hz Fb, with the trade-off being a ~3dB lower effective efficiency. If you feel like gambling with these specs and don't mind the lower efficiency, then how big of a cab can you handle?

GM

[Ouroboros]

With the low Qt, they are ideal candidates for active equalisation in the form of a Linkwitz transform circuit between the pre-amp and the power-amp.

[dnsey]

Interesting thought, Ouroboros.
It might be tricky though to accomodate the coaxial tweeters, which have a notoriously odd native response / impedence, which ois compensated for by Tannoy's peculiar crossovers!

[GM]

Originally posted by Ouroboros
With the low Qt, they are ideal candidates for active equalisation in the form of a Linkwitz transform circuit between the pre-amp and the power-amp.

Yes, this allows a small cab that you can dial in a low LF corner and Qtc, but this assumes you either have no need for any dynamic range beyond what is required for quiet background music or you enjoy hearing the driver in terminal distortion at normal listening levels since these have very little power handling capability.

GM

[rdf]

Originally posted by dnsey
I have a pair of Tannoy 10" Monitor Golds ...
Would the Tannoys suit TLs? Anyone tried them?

Hi dnsey, I investigated the same thing for a pair of 12" Golds waiting for cab's. The Gold's were made for a long time and there were many different versions with various surrounds and voicecoils/magnet parameters. No effort could make some, using Martin King's TQTW sheets, sim into an acceptable TL. Others show excellent promise. Your drivers will have a serial numbers, these links should help get an ides if you have a chance:

http://users.bigpond.com/tunnelgap/T...alNumbers.html
http://www.hilberink.nl/speaker.htm

Ultimately though, given their age and, if you're not the original owner the possibility the drivers were re-coned at some time, the only way to be certain is measuring the T&S parameters yourself.