tannoy

The cabinets for my
Tannoy Monitor Gold 15'

The cabinets in my listening room. As you can see they are home made 200 Litre
"Tannoy York Rectangular" design. They are improved copy's of the original Tannoy York design that had some design flaws.
The original York had some problems with the side, front and back panel resonances, cabinet rigidness and distribution angle of the HF section.
Also damping of the original York was insufficient, the sound was somewhat coloured in mids and highs and a little muddy in the lows.
The original York was a reflex system, this cabinet is closed.

Below the open 200 Litre cabinets.
Used materials: plain wood beams, water resistant plywood for the walls, a little chipwood board as wall support. Bitumen, cork, kramforac, industrial wool, furniture wool, foam and sand are used as damping materials. Two component paints are used to seal the wood of the cabinet, also veneer is used to complete the exterior. These cabinets are closed airtight and have no port or horn. They are 1.20M high and weight per cabinet is >100 Kg.

The primary damping material, bitumen (used on roofs) and cork cannot be seen, because they are fixed directly to the walls of the cabinet. The kramforac is as you can see mounted on the wooden beams, leaving a small air gap between primary and secondary damping method. In the room between these two there is some industrial wool applied to avoid acoustic resonance. The main front/back brace consists of 5 beams joint together and 0.5 cm shorter as the distance between front and back that gives the opportunity to get tension between the front and the back panel to keep these panels as quiet as possible. The blue foam strip on the brace is to avoid resonances, that is also applied later at the connection panels. The tube in top is a foam tube to keep the third damping method in place. As you can see on top of the back there is a hole for the connection panel.

Here we are at the next stage, the third damping method, industrial wool is loosely applied in the lower section of the cabinet. The cross over unit and the connection panel are mounted. As you can see here the cabinet has a small stand.
What you cannot see is that the back panel in fact consists of 3 glued and screwed together panels and is filled with sand between layer 2 and 3, also you cannot see: the back is also braced above the connection panel.

A detail of the modified cross over unit mounted on the main bracing.

*

The third damping method: industrial wool.

The completed situation. The wool is loosely applied and as you can see the foam tube keeps the wool in top. The grey stuff is some other type of wool that is used in chairs, it is used only to surround the speaker unit, as a sort of treshold to avoid standing waves in the cabinet, it has a significant different damping factor compared to the other materials.

*

Now the front with the mounted speaker can be joined together with the cabinet. As you can see there is some damping material fixed already around the speaker unit, this is not yet the final situation. The holes for the bracing screws are applied with special airtight kit and later after the screws are mounted, with silicone kit. Silicone kit is easely removable in case of corrections to be made afterwards.

Above the front of the cabinet with the sealed screws of the speaker. On the lower part of the front you can see the huge screws of the brace covered with silicone glue as sealing. These screws join front and brace under tension. The slotted screws surrounding the speaker unit are used to join primary and secondary part of the front panel.

*

These cabinets are taken out of use in 2016 and disassembled in 2017. New cabinets, smaller and different are built.
It was quite interesting disassembling these cabinets and see how well they were constructed back in 1968/69,
no wonder they sounded so well, in fact a pity to scrap them.

The front with cloth and TANNOY name tag.

Read on at the previous page, click here.