Tannoy DC cabinets

[hifi_dave]

As a new member, I'm going to start my first thread on The Art of Sound.

I have a pair of pretty well immaculate Tannoy Little Gold Monitors (LGM) with as new 12 inch drivers, not sure of their designation.

Question is, whilst doing a lot of the good things that big Tannoy DC's do, they don't have a lot of bass. What there is, is fast and punchy but little extension or weight and I'm guessing they need larger cabinets.

Anyone have ideas for cabinets which will do the job and (hopefully) not tax my non-existent cabinet making skills ?

[Magna Audio]

Hmm,
As you know I am planning a pair of ~180-200L rectangular GRF replica's.
Only concern is not wanting to loose any of my current lovely double ported bass.

I'd go for a pair if replica 12" DMT's given what you want. I've heard 12" DMT's and they rock - good all rounders - certainly not bass shy.

My plan is 12mm high density chipboard bonded (PVA'd) to 8mm MDF to give 18mm wall thickness.
Homebase will cut all the panels on there reasonable precision and high speed cutter (this they will happily do if you buy the wood from them + if they are quiet in store at the time. This will be quite a big cutting job if you think of each panel and times 2 different materials).
The mix of materials is said to give the best resonance reducing properties.
Depending on design you will need to brace the cabs with figure 8 shaped cutouts. The GRF has it's own bracing built in the back loaded horn arrangement.
You will have to measure, saw, cut and drill though - all good basic DIY'ing.
Glue/screw: use PVA, You will need cabinet clamps or clever use of racket straps bracing pieces to keep all square.
The front hole needs a pilot hole in the centre and then a router guided from the pilot hole to make the circle. One hole suitably bigger in one material layer than the other to allow a recess for the driver to bolt into. Captive spikey nuts to hold the driver.
Transplant all from your existing speakers. Drivers, crossover / level and roll off panel & speaker terminals or get some new ones from Aladdin's cave (Maplins).
Wadding/damping can be got off Ebay or other supplier. Clean install loft insulation (no gloves / mask needed type) would do if you are on a real budget.

Finish - keep the clean square cut Homebase gives amd you could try some iron on veneer to wifes choice or round the corners off and apply the sort of grey finish they use on 12 & 15" DMT's - I like that finish in an understated way.

I can send you a simple spreadsheet I made for sizes and it generates approx. costings.

The basic GRF design & others of bass relfex's I have found on the internet. These are out there working well. I can send you the plans.
The GRF is supposed to do wonderful things. Not sure if this if confined only to 15" drivers? Otherwise a reflex with suitable sized ports ala DMT would up the bass with decent sized cabs.

A good cab size for a 15" is 180 to 200L still some WAF
For 12" perhaps a little less (DMT is around 50L from memory) but the bigger the cab the better the breathing and overall sound - look at the volume of Westmisters (530L with 15" DC driver).
Considerations of room size. How big is your room?

If you PM me your email I'll send the above and anyother info.

[hifi_dave]

Hi Steve,
Thanks, there's a lot of information there.

For some obscure reason I have never got into Tannoy DC's until 18 months or so ago when I discovered the joys of the latest Prestige range, which is selling well despite the retro looks. However, I know little about the vintage models apart from the GRF and various models like Cheviot, Lancaster and LRM. I don't, for instance, know about the DMT. What is that ?

When I get around to building cabs for my 12 inch drivers (what are they by the way ?) I think I will find a man wot does because I will make a pig's ear of it. I admire people who can make things to be proud of but my skills are limited to decorating and hard-core turntable set up.

My details are in the profile section and I would be grateful for a suitable cabinet diagram and any other info.

All the best,
David

[DSJR]

PLEASE check the model of driver in the LGM's as Tannoy appear to have made umpteen different versions of each generation.

[hifi_dave]

That would entail the removal of at least 40 screws.

Tell you what - I'll give you biscuits to dunk in your tea if you take a peek. Failing that, I suppose I'll have to do it. I was hoping that there was only one option for the LGM.

[Magna Audio]

Here's some info on 12" DMT's. They are modern (I think they still sell them).
A 90's pair goes for around £400-600, perhaps less if you can get in first on a studio clearance. They are a fine speaker if wife will take the looks.
The big brother 15" DMT is a great speaker. The cabs of both are solid as anything. Tannoy did not repeat the mistakes of the earlier flimsy cabs.

http://images.google.co.uk/imgres?im...a%3DN%26um%3D1

Here's what I would have given the room The 215's.

http://images.google.co.uk/imgres?im...a%3DG%26um%3D1

I do however think a pair of Avantgarde Duo mid and treble horns would pair well with a 15" Tannoy bass cone...