Which Tannoys, folks?

[Reffc]

That's a very interesting article although interestingly it doesn't mention some of the drawbacks of the Tulip Waveguide system such as introducing slightly raised distortion between 1KHz and 2KHz and the importance of tuning crossovers to various enclosure designs. I must admit I prefer the pepper-pot design of the earlier models and the more expensive prestige DCs but like the Turnberry for the excellent cabinet design, room friendly size and build.

Still deciding between the Turnberry or the Mansfield and it's 6 of one and half a dozen of the other at the minute...but I think that the vintage Tannoys just may have it!

[Reffc]

Decision made:

have decided that the Mansfield's will stay....sort of! The HPD units will stay as will the crossovers. I am designing a 150 litre enclosure (ported) which will make the most of the 315HPDs. This will be built in 25mm Birch Ply and veneered in European Oak. Shape wise, it won't be a box. Front baffle board will be 450mm wide and in plan, the sides will come in to 200mm deep before being angled at 45 degrees inwards to a total cabinet depth of 350mm. They will stand around 1.1m high. Port will be a 4 inch port, 6 inches deep located in the lower half of the cabinet to one side.

This shape will ensure a very rigid construction and the volume and porting will be designed for a 30Hz in room response before roll-off. This will take some weeks to complete but I hope to make a start within the next week or two and will document progress. It is aimed at matching the performance of something like the Prestige Kensington for a lot less money. Funds to manufacture will come from the sale of the Turnberrys. I estimate timber and veneer costs to be about £600. I will be receiving assistance in the shape of a computer modelling suit for the cab design... I want to make the "perfect" 315 loudspeaker. Exciting times!

[Reffc]

Have modelled current enclosure V's proposed enclosures:



The yellow line represents the Mansfield cabinets (and is an imporvement on the Lancaster cabs response).
Bottom green line represents a 150 litre vented enclosure.

Top green line represents a 140 litre vented enclosure.

I've modelled other volumes and vent arrangements but going larger with the 315HPD leads to a hump at 35 Hz which would induce boomy response. Going lower to 100 litres with a vented cabinet betters the current sealed enclosure and gives a nice smooth response but the best response seems to be for 140 litres where the port is tuned for 30Hz at -6dB.

I'll have some further attempts at optimising the enclosure size and design, but so far, 140 litre vented cabinet has it.

[walpurgis]

Just thinking laterally, but there is a easy option that should give results rather similar to the sound you have from the Mansfields and that is to mount a pair of HPD 295A drivers in the Turnbury cabinets, it has been done before successfully. I personally found the sound quality of the 295A superior to the 315, I've owned both and still have a pair of HPD 295A Eatons. The 10" driver still packs a punch and has a lovely mid and top.

[Reffc]

Just thinking laterally, but there is a easy option that should give results rather similar to the sound you have from the Mansfields and that is to mount a pair of HPD 295A drivers in the Turnbury cabinets, it has been done before successfully. I personally found the sound quality of the 295A superior to the 315, I've owned both and still have a pair of HPD 295A Eatons. The 10" driver still packs a punch and has a lovely mid and top.

That's not a bad idea at all, but I have a perfectly decent set of 315's now and all they really seem to need is a few crossover tweaks to drop HF response slightly (between 3 and 10KHz) and some more beef low down (cabinet issues) and job's a good 'un.

Several ways of doing it:

1. Easy way: drill a vent hole into the lower half of each cabinet to take a 100mm diameter, 150mm long port (modelled, this results in MUCH improved bass response);
2. Build new cabs to 150 litre dimensions and make them ported;
3. Do as you suggest and keep the Mansfield cabs.

I've lived with the Turnberrys and Mansfields for a little while now and the Turnberrys knock the older speakers into a cocked hat for looks and for bass response. The HPDs though have a lovely mid range and are way more detailed and I'm willing to sacrifice a little bass for that. However, they are ugly

I have always fancied building my own loudspeakers, and this as a great opportunity to take the HPDs and fit them into something as lovely as the Turnberry cabs. I have two designs roughed out now and will decide on which one gets the green light tomorrow after a little practical research into how to build each! They won't be conventional boxes and both designs I reckon will look stunning. I can also play with the HPD crossovers and tweak them a little to optimise the HF response.

That's the plan. I know I have a great set of HPDs so plan to use them. The Mansfield cabs will be sold to whoever would like them. They are great cabs for sealed boxes and way better IMHO than the Lancasters (better bass response and more solid too) but I know that I can squeeze more LF performance from the HPDs so that's what I aim to do, all wrapped up in something which will suit the room.

[walpurgis]

As a total aside, I just took my Cheviots out of the system and hooked up my Eatons. I haven't used them seriously for a year or so.

Wow, I'd forgotten what these can do! They have the same pepperpot tweeter as the 12" Monitor Gold and it shows, so transparent and clean through the mid. Lovely. I suppose while I'm at it, I should give the System 800s a whirl too, they are also superb.

I'll probably have to make some space and sell a pair soon, but which ones? They are each great in their own way, I'm very torn as to how to make the choice.

[southall-1998]

As a total aside, I just took my Cheviots out of the system and hooked up my Eatons. I haven't used them seriously for a year or so.

Wow, I'd forgotten what these can do! They have the same pepperpot tweeter as the 12" Monitor Gold and it shows, so transparent and clean through the mid. Lovely. I suppose while I'm at it, I should give the System 800s a whirl too, they are also superb.

I'll probably have to make some space and sell a pair soon, but which ones? They are each great in their own way, I'm very torn as to how to make the choice.

I'll take the System 800s if you decide to flog them in a few months

[walpurgis]

I had a feeling you might say something Shane.

I suspect it may be the Eatons to go, sadly, as they sound quite similar to the Cheviots. The System 800s have a sound of their own.

Not making a decision yet, as I'm very fond of them all.

(how are the Magisters going by the way?)

[southall-1998]

I had a feeling you might say something Shane.

I suspect it may be the Eatons to go, sadly, as they sound quite similar to the Cheviots. The System 800s have a sound of their own.

Not making a decision yet, as I'm very fond of them all.

(how are the Magisters going by the way?)

To be honest I'm not using them. Because my room is no good for them!

Shame your thinking of letting the Eatons go!

[Reffc]

Have picked the veneers for the new cabinets. Main cabs will be veneered in this:



At the front the edges of the cabinets will be in structural solid timber rebated to accept the 25mm sides and front baffle board, the edges of the timber being rounded for the best baffle performance and to make the front aesthetically pleasing. Timber will be a 1100mm long 80mm by 80mm section of solid European Walnut:



The contrast between the two is lovely and the Sycamore Cluster brings a very contemporary and fresh look to the speaker enclosures.

Watch this space...mock up of speaker cabinet options coming soon!