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andersen09 18th August 2010 12:24 PM

"Small" enclosure for Tannoy 15"
Hi guys,

I am about to start a new Tannoy project and need your advice.

The project will be using a set of old Tannoy K3808 (SRM). They will be reconed to K3838 with hard edge, have new HF diaphragms and new filters without controls. Basically only the frame and magnet will remain.

For enclosure I cannot (and will not) build 200 liters+ boxes so my limit is something in the area of 100-150l - and this leads to the question:

Do any of you have experience or information about the following designs for Tannoy 15" taking the relatively small volume into account?

1) Closed
2) Vented with port
3) Vented with acoustic vent
4) Rectangular GRF

Thanks a lot and greetings from Denmark

PeteMcK 18th August 2010 11:26 PM

using the specs here: Tannoy Monitor Thiele & Small Parameters
Unibox gives me 120L tuned to 38Hz for an F3 of 41Hz; if you want to go lower it looks like an EBS alignment is the only option, with some electronic low end boost.

GM 19th August 2010 03:38 AM


I imagine these folks have plenty of experience: tannoy : Tannoy Dual-Concentric loudspeakers


Charles Darwin 19th August 2010 06:11 AM

Am I wrong in thinking that the 3808 (SRM M1000) is the hard-edge (folded paper) driver and the 3838 the later soft-edge (rubber) derivative from the SRM M3000?
Will your driver have the TS parameters of the 3808 ,the 3838 or its very own individual set?

Either way in my experience Tannoy drivers do not do particularly well in closed boxes.
I modelled my 3148s and in a closed box they roll off from about 150Hz regardless of box volume. I think something like PeteMcK suggested is your best bet, obviously depending on the actual TS data of your drivers.
Rectangular GRF are about the size of a 300L box btw.

Holty 19th August 2010 01:10 PM

You could look at some Onken cabinets. I used some 12" Monitor Golds in 127L cabs, so you should get a good bass with that size or even up to your maximum of 150L. As i said the bass response from these multi ported cabs can go very low.


andersen09 19th August 2010 02:49 PM

Hi guys,

Thanks for the interest and you responses!

Thanks, this is the similar I get from WinISD Beta. Of course it depends very much of the reliability of the TS data svailable... I have not yet measured the drivers as they are not reconed yet.

Thanks, I have not joined that group yet - will do :)

@Charles Darwin
The speakers will be reconed to K3838 i.e. everything will be changed leaving only the chassis behind (identical for 3808 and 3838) so I expect the TS to be identical to 3838. I could try with the 3808 first and recone if I am not satisfied however the bass performance of 3808 is not good (and not intended to be either)

That sounds great and I missed the Onken on my list. My impression was that Onken primarily is used for bass - would they be suitable all the way down to 1Khz? I really like the energy and punch from those boxes and would be interested if you would share details of your design?

Thanks guys!

GM 19th August 2010 03:02 PM


Originally Posted by Charles Darwin (
Will your driver have the TS parameters of the 3808 ,the 3838 or its very own individual set?

Either way in my experience Tannoy drivers do not do particularly well in closed boxes.

I wondered about this and why I recommended asking the Tannoy cognoscenti, but with Altec or similar it usually means a set of specs that's somewhat different, so ideally need to be measured for best results.

That said, assuming they will still be low Qts and fairly high Vas, how low it will go ~flat for a given net cab Vb will be determined by how much output impedance is used to raise its effective Qts, i.e. trade efficiency for BW. Design a sealed alignment based on a low Qts and drive it with a typical SS amp and it becomes a mids-up speaker as you noted and even a vented alignment will only be a small, high tuned mid-bass.

Anyway, if it were mine I'd just build the biggest cab I could tolerate, tune it to ~Fs and add as much EQ as required to get the flattest in-room response to at least ~42 Hz.


andersen09 13th February 2011 07:24 PM

Hi again,

Small update here: I finally decided to go for the rectangular GRF cabs.
Some examples here:

Tannoy GRF

I'll post a link to the project later


revintage 14th February 2011 09:07 AM

Hej Jesper!

A strictly designed Onken with KS3838 will give you a Vb of 131dm3. F3 will be 49Hz. It will not work with 3808 giving a Vb of 59dm3 and a F3 of 87Hz. But good luck with the BRFs.

andersen09 16th February 2011 11:31 AM

Thanks... uhhh hard choice. GRF or Onken. I have heard Onkens before (only as bass) and they where very good. Never heard GRF, only read nice things about them.

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