Tannoy Enclosure

[pre65]

Are the old cabinets going to be scrapped ?
(No-I don't want them . )

Yes. I'm amazed they lasted this long.

You could try cutting the back off and see how they sound then.

[Scottmoose]

So far I put in what I knew and then wiggled tuning frequency to get the duct length that are in these older cabinets. And that gave the wildest LF peak. Not only for mine but a couple of the other older cabinets. Either I have something wrong or that's what I actually have and that's an issue with these older cabinets?

Quite common with older Tannoy vented boxes & similar, where the enclosure volume is often excessive for the tuning frequency & driver requirements (unless used with a ~impedance matching amplifier & suitably damped).

Chris did measure a great hump at Owston last year but of course couldn't be sure what it was down to: room, mic position or speaker or combinations of any of it.

Likely a combination, at least to a point (& gated measurements aren't very accurate in the LF anyway) but as noted, this kind of response isn't particularly unusual with older Tannoy cabinet designs, at least going by what driver data is available on-line. Ideally, those old boxes & / or their ducts were damped via the old click test -unfortunately not many were! Now you know the reason for some of the vented box volumes I noted above. Put those in and see what you make of it.

[izzy wizzy]

Are the old cabinets going to be scrapped ?
(No-I don't want them . )

Yes. I'm amazed they lasted this long.

You could try cutting the back off and see how they sound then.

I'm limited to 600mm wide going forward hence this thread.

[IslandPink]

Is there a web link to the parameters of your driver ?
Specifically Qts, Fs and Vas ?
If so we can reduce the experimentation time from 10 years to something shorter.

[izzy wizzy]

Is there a web link to the parameters of your driver ?
Specifically Qts, Fs and Vas ?
If so we can reduce the experimentation time from 10 years to something shorter.

There is http://www.44bx.com/tannoy/Tannoy_ts.html. Mine being the Monitor Gold 15.

I did last night what Scott suggested and got graphs for my driver as he showed in his examples; 3 sealed and 3 vented alignments. I also played with variations of the Arden cabinet which is 175l with 2 and 3 ports of easily available sizes to see if there was a tuning option by bunging some of them.

Also sim'd my current cabinet a bit better. Don't think I got the best out of it but that's history now. I liked some of the Arden variations from the little I know but have yet to get a chance to post the graphs. Hopefully I can post in the next day or so.

[izzy wizzy]

Hope this makes sense.

First 3 are sealed, 3 after that vented.

Max Flat

Max Flat Delay

Crit Damp

[izzy wizzy]

3 vented

QB3

BB4

EBS3

[izzy wizzy]

Then tried an old Arden cabinet which was for the HPD driver but with my driver in it. Fiddled with tuning frequency until I got the port length.

Arden Old

Being a novice, it's easy to look at these and say the Arden looks best but from what's been said, there's a whole lot of other things going on when the room comes into play and there's other aspects that may offset what looks a good response. Room gain is something I don't know much about other than it can lift the droppy ones up by quite a bit as I'm guessing part of that is the back wall and side walls.

Which leads me to a question about the advanced box section that has parameters for Ql, Qa and Qp. A post on DIYAudio indicated some values for these like:-
Ql, enclosure losses could be 5-20
Qa damping material moderate 30, heavy 3, half filled 7
Qp port losses, a good port being 100

From my own experience, I'm not a fan of stuffed cabinets with the Tannoy as it knocks the life out of it. But with the Yorks I have, that led to a boomy reponse. I should have experimented more with appropriate materials.

The Legacy Arden is a similar size, 175l or so with 3 round ports that look like about 80mm dia. Here's a guess as to what it might look like.

So that's a few graphs. Not sure what to look at next.

[IslandPink]

Good effort. Will try & digest a bit more tomorrow. I was thinking sealed would be a bit limited with the Qts of the driver around 0.2, so that confirms it.

[izzy wizzy]

I play with winisd before work, at lunch, after work. Read forums, dream graphs blah blah. I'm not alone being a bit confused about this but hopefully something is sinking in. A bass players forum has helped quite a bit. Don't tune it higher than a note you're going to play otherwise it farts Well that's what I got out of it. The other thing was you can have your box loud, low or small.

I keep coming back to a SBB4 alignment. I can't help thinking if I can have a big box, why not? But I'm guessing the tradeoff is don't push it too far, don't aim for flat as there's room gain to consider. I would wager, just in real life, if you make it do something like peak too much, it will lose control; life on the edge. Take the advantage it gives but not too much. The group delay for a big box gets high at the very low frequencies but by then, there's no music and for the most part, it stays lower than the other options. This is also confusing.

I'm also imagining, the steeper the rolloff, the more ripple? So the rolloff won't be as smooth so sound a bit lumpy. Another WAG.

And room gain isn't in the sim. In fact it seems to be the major head scratcher variable. And then there's different room constructions which also play into that. Current house brick but next houses probably more leaky in the bass.

So if any of that is vaguely right, tuneable ports seems a way forward not only for now but the future. That might be tuneable in length or it might be a number of them where some can be closed off.

[Dave the bass]

..... A bass players forum has helped quite a bit. Don't tune it higher than a note you're going to play otherwise it farts Well that's what I got out of it.

Pfffttttt... bass players.. what do they know!

[chris661]

Yeah, room gain is a big variable.

If it helps, my 2x10"+HF PA speakers have 4x 3" ports on the back, and I use rubber bungs to block either two or three of them if there aren't any subwoofers. LF tuning frequency goes from 70 to 60 to 44Hz, with LF extension varying accordingly.

Of course, the cabinet is under-sized for the 44Hz tuning, so some EQ boost is required to get them flat again. With that in place, it works nicely.

Just a thought - would there be an option of an analogue EQ circuit between the pre and power amps?
The in-room measurements I've done so far tend to show one big peak (in my case, 40Hz), with a few others that are quite a lot smaller. An analogue notch filter centred on the biggest peak would mean you've got a much flatter LF response, without having to introduce DSP.

Chris

[ed]

..... A bass players forum has helped quite a bit. Don't tune it higher than a note you're going to play otherwise it farts Well that's what I got out of it.

Pfffttttt... bass players.. what do they know!

word!

whilst on this topic..

anybody know if it's possible to import winisd personal driver details from version 0.44 into the new 0.7.0.655 or whatever it's called. I have about 60 drivers in version 0.44 and it's gonna be a real pain entering them individually by hand....although some of them I'm unlikely to ever want to use again....

edit: I've emailed choong but the email bounced so Ive fowarded to Juha...no reply so far.

[Ray P]

Pfffttttt... bass players.. what do they know!

Perhaps you could enlighten us - shouldn't take too long...

[izzy wizzy]

Done a lot of reading and have come to the conclusion that most threads get to a point where a decision has to made about alignment and some other stuff. All this presumes that the person knows something about speakers which I don't. Those of us that don't know anything much get to this point and just have to make a WAG.

So my guesses are, SBB4 seems an alignment I might like. I'd like some tuning ability as I have no idea what the profile of the bass response should be, what the room gain will be, what room nodes I'll encounter. I think they will sit near a back wall for the most part but might be able to be moved into the room.

In an iterative process, using boxnotes and winisd, I came up with a box 1170H x 530W x390D. Using boxnotes, was able to move the resonances around so they were fairly spread out. Apparently the top to bottom resonance is bad and big as it's low but not much I can do about that. Apparently closed cell foam can disrupt it a bit as can felt so maybe a layer on a shelf brace or two might help?

Plugging the working volume into winisd I get 4 variations; 3 vents, 2 vents, 1 vent and the blue, no vent. That seems like decent tuning variation in the absence of knowing any better. I get the feeling to tune the box to get too much lift out of it could result in boominess which I got loads of now and don't fancy any more.

Then there's group delay. From what I can make out, down very low, it doesn't make much difference so here it is. Some of those hills look large but they're real low. Not sure what this all means.

Ray's thread got me excited about fancy shapes and all kinds of good ideas, but ultimately I have to realise and accept, I want this to happen and going that route will mean it's too complicated for me to build so this has to be a simple box I can get CNC cut so I can stick it together. I can model in Sketchup and export the file to do this.

If any of this makes any sense or not, feedback and ideas would be welcome