DIY TANNOY DC 3000

[bull041161]

Hi all thought i would post some pics of my diy dc3000 here are the build pics, The sound is pritty good but thay sound a little boxy do you think i should add a port of some kind i know the origonal tannoy dc 3000 had a sloted port on the back but i have not put one on. What sound differance would a port make this is my first diy speaker project. Any help would be great

[alan-1-b]

Before you cut any holes for ports, I recommend you add some better absorbent substance to both the driver chambers and listen.
More absorbent, when suitably installed, will reduce the "boxy" sound.

Long-haired wool is best, or try the apparently similar wadding sold under the Soniqs brand name.
For Soniqs, look in:
www.world-designs.co.uk

Fibreglass, such as easily available from Hardware shops as roofing batts can be got to work well,
and somewhat better is Rockwool or Mineral Wool -{the same substance is known by both names}.

I will describe how to best position any absorbent if you want to try any of these.

[bull041161]

Originally Posted by alan-1-b

Before you cut any holes for ports, I recommend you add some better absorbent substance to both the driver chambers and listen.
More absorbent, when suitably installed, will reduce the "boxy" sound.

Long-haired wool is best, or try the apparently similar wadding sold under the Soniqs brand name.
For Soniqs, look in:
World Designs Home Page

Fibreglass, such as easily available from Hardware shops as roofing batts can be got to work well,
and somewhat better is Rockwool or Mineral Wool -{the same substance is known by both names}.

I will describe how to best position any absorbent if you want to try any of these.

Hi thanks for reply i forgot to take a pic of the finshed damping i did add some of the origonal white wading that was in the the speakers but only a couple of sheets in each. Thay were dc 2000 but i just built the biger box

[alan-1-b]

When you have time, take another Photo, or two, which show exactly how the white wadding is positioned in the cabinet, and Post the photo/s here.

Also, is it a semi-sealed surface wadding, or very open-weave surface ?

Type and positioning do make a difference to the sound.

[bull041161]

Originally Posted by alan-1-b

When you have time, take another Photo, or two, which show exactly how the white wadding is positioned in the cabinet, and Post the photo/s here.

Also, is it a semi-sealed surface wadding, or very open-weave surface ?

Type and positioning do make a difference to the sound.

Hi its a white wading with fluffy fure texture on both sides. In the unit that holds the tweter i have folded one from side to side and another bottom to top in an arc shape if you know what i mean and in the bottom one were the bass unit is i have just put one piece of wadding in same as the others in an arc shape. I have about 4 pieces left i did not put any wadding in the very bottom just the thick rubber carpet underlay

[Charles Darwin]

I use white massam tops from these people for stuffing:
Wingham Wool Work - Quality Fibres and Accessories

[bull041161]

Originally Posted by Charles Darwin

I use white massam tops from these people for stuffing:
Wingham Wool Work - Quality Fibres and Accessories

Hi thanks for the link i still have some from the origanal tannoy speakers but not shure how tightly to pack the chambers, Is it just a case of keep adding till it sounds right. Do i add to both chambers or just the bass chamber

[Charles Darwin]

Both I'd say. Experimenting is the key here.
If you decide to port them you will need to leave a stuffing-free path between the driver(s) and the port.
I use Black Jack DPM to attach the damping material.
www.toolbank.com | Everproof DPM 5 Litre 908

[bull041161]

Hi all thanks for all who helped i have added more wadding thay sound alot better now but i would like a bit more bass extention would adding a port give me that allso what size port and were to put it back or front. Thanks for any help

[Charles Darwin]

Yes, adding a port would give you better bass extension. All their drivers are designed to be ported.
To determine the port area and length you need the Thiele/Small parameters.
Unfortunately I can't find them anywhere hence I suggest you contact Roger at Lockwood Audio.co.uk. He is very helpful and if anybody knows it'll be him. Lockwood have been working with Tannoy for about 50 years now and are the only Tannoy accredited supplier of spares for all drivers no matter how old.