Below the older models Chris made some years ago:
Below the older models Chris made some years ago:
Cris has made these big and professionally constructed horn cabinets.
These Autographs, built out of ply as the originals, but with solid Imbuia wood finish, extra 16mm back panels and a solid horn as seen. They sound ver good in the bass but as far as I am concerned the Tannoy HF driver leaves a lot to be desired.
On the top is a ribbon supertweeter which runs from 10kHz up to 70 kHz at 100dB sensitivity. This made a very noticable difference and currently I am running some ribbon units which come in at 1 kHz (sensitivity about 90dB) with the Tannoy HF driver disconnected.
They are as the original Autographs with the exception of the front horns. I stole that idea from the Westminster Royals although the WR have a very much shallower flare.
The surrounds on my HPD's have been replaced by a chap who repairs Tannoys in South Africa for the Tannoy Prosound agents and also the SABC (local version of the BBC).The two mods given below are from this chap. As the cabinets were designed for the red's and silvers which have a stiffer suspension the HPD's tend to be very bass heavy (around 102dB) the HF drive has to be adjusted and when you do that they become a bit on the harsh side. This can be done by removing one of the gaskets between the HF dome/voice coil and the magnet. There should be 3 gaskets by the way.
A further mod can be carried out which I have not done as it means completely stripping the speaker and that is to drill out the holes in the pepperpot to give less pressure loading which will reduce distortion and also, unfortunately, less sensitivity which can be partially rectified by the gasket mod. In the Autograph cabinets I suppose the drive to the main cone could be reduced to get the correct treble/mid balance.
The response of the Autograph in the bass
is flat within 4dB from 200Hz down to 20Hz. 32' Pipe organ bass (bottom C is 16
Hz) is something to hear at loud volume. The bass vibration can be felt in the
main house walls (9" concrete) from the outside! Bass is tight and fast.
Amps driving the Tannoys are SE, parallel 300B's, with max power of 15 watts.
Chris also constructed an organ, a picture below:
You can email Chris at:
© PE1MMK Hans Hilberink & Chris. 2001 & 2007.
