[painkiller]

We were getting way off topic on the Visaton B200/Eminence 15A thread, so here's a separate Tone Tubby Thread.

There seems to be some interest for these drivers, and it would be nice to share some information and thoughts. And eventually some experiences with baffle design, matching woofer and tweeter drivers, crossovers, phase plugs and so on.

Here's the only information I've been able to get:
Name: TT Alnico 10
Type: Standard one-way driver
Fs = 107.32 Hz
Fsa = 52.36 Hz
BWs = 12.72 Hz
Vas = 24.5 Liters
Cms = 1.28E-04 m/N
Mmd = 16.8 g
MMr = 5.4 g
BL = 6.78 Tesla/m
Efficiency 94.64 dB lw/lm

Qms = 11.13
Qes = 1.58
Qts = 1.39
Re = 6.5 Ohms
Zmaxs = 130.2 Ohms
2.83-V SPL = 94.64 dB
1-W SPL = 95.1 dB
Kr = 0.000
Xr = 0.000
Ki = 0.000
Xi = 0.000

And Lynn Olson has done some measurements og the 12" here:
http://www.nutshellhifi.com/MLS/MLS6.html

[painkiller]

First question:
Has anyone modeled the 10" driver yet? What kind of frequency extension should we expect?

Next question:
Any idea for a matching tweeter? I've heard of people using a Fountek ribbon tweeter. Other's claim that ribbons and widebands do not match. What's the deal?

Third question:
Does the Tubby drivers have an ok bass extension, or is it mandatory with a woofer?

Any chance of making a three way system with 1st order crossovers, and not use EQ?

[gitarretyp]

Next question:
Any idea for a matching tweeter? I've heard of people using a Fountek ribbon tweeter. Other's claim that ribbons and widebands do not match. What's the deal?

Third question:
Does the Tubby drivers have an ok bass extension, or is it mandatory with a woofer?

Any chance of making a three way system with 1st order crossovers, and not use EQ?

Where'd you get the T/S parameters?

With the high FS and likely very little to no linear excursion (most guitar speakers have no linear excursion), they will not have much bass extension and would probably be best high passed at 2-300 Hz.

If their frequency response looks anything like the 12", which i would expect to some degree, you could probably make it work well with passive filters.

For a tweeter, i'd look at compression drivers on a waveguide. Something like the B&C DE250 or Beyma CP380 on a DDS ENG 1-90 or 18 sound XT1086.

[nullspace]

For what it's worth, I'm working on a 2.5way using 2x TT 12" on open baffle plus compression driver/ horn (presently, 1000hz 50deg. conical + either B&C DE250 or Beyma CP380M). Even with the helper woofer, I'm planning on the low-end just making it to 100hz. While that means I'll need to use a sub, it buys me ~100db/1W for the mains.

I think a three-way crossed-over passively would be quite difficult, for a variety of reasons. Currently, it looks as though I'll be passively crossing the TTs and the horn, but my sub will have a PLLXO and dedicated sub amp.

I've measured the T/S for the two TT I have in house and unbroken-in they are pretty close to what is (or was) posted on the A Broun Sound website.

Regards,
John

[ttan98]

I've measured the T/S for the two TT I have in house and unbroken-in they are pretty close to what is (or was) posted on the A Broun Sound website.

Regards,
John

Hi,

I can't find the T/S parameters at A Broun Sound website. Can you post your T/S here. Thanks

[nullspace]

Here's a copy of ToneTubby's #s, courtesy of archive.org: http://web.archive.org/web/20060215064937/www.tonetubby.com/specs12a8.htm.

The only # missing is Le, and I came up with .177 and .191mH.

Regards,
John

[painkiller]

Thanks! And here are the specs page for the 10" also.
http://web.archive.org/web/20060215064937/www.tonetubby.com/specs10a8.htm

I see the 10" driver has a couple dB lower efficiency, so maybe this is easier to couple with an OB woofer? I understand the point of an active woofer though.

These compression drivers all have extremely high spl. Aren't there any tweeters that can match the TT without using an L-pad? Any special reasons for choosing compression drivers and horns? Are these known to match well with big widebands?

I've tried to get in contact with sales at A Brown Soun, but haven't gotten any reply yet. Does anyone know which e-mail adress I should use?

[ttan98]

Here's a copy of ToneTubby's #s, courtesy of archive.org: http://web.archive.org/web/20060215064937/www.tonetubby.com/specs12a8.htm.

The only # missing is Le, and I came up with .177 and .191mH.

Regards,
John

Hi,

Thanks, did you perform a freq response curve? If you have can you show it here. It appears those guys from Tonetubby has never display any freq. resp curves for any of their drivers.

Thanks

[ttan98]

Painkiller or Nullspace,

Using T/S for 10" Alnico,

Fs = 107.32 Hz
Fsa = 52.36 Hz
BWs = 12.72 Hz

What is the difference between Fs and Fsa and what is BWs? Is resonance freq. =52.36Hz?

[painkiller]

Fs = 107.32 Hz
Fsa = 52.36 Hz
BWs = 12.72 Hz

What is the difference between Fs and Fsa and what is BWs? Is resonance freq. =52.36Hz?

Fsa is the lower resonance frequency. I believe it is measured with a 75% added cone mass. Don't know what it means in real life though.  Resonance frequency is Fs = 107.32. Don't know what BWs is.

Maybe I should make it clear once and for all, I'm no speaker guru. I'm fresh when it comes to speaker design, so my posts should be taken with a pound of salt.

[ttan98]

thanks painkiller.

I ask TubbyTone similar question, I didn't get a response.

[iON]

Third question:
Does the Tubby drivers have an ok bass extension, or is it mandatory with a woofer?

With the high FS and likely very little to no linear excursion (most guitar speakers have no linear excursion), they will not have much bass extension and would probably be best high passed at 2-300 Hz.

Since the TT is a guitar speaker it must satisfactory reproduce at least the guitar's low E string, which is circa 82 Hz (unless down tuned) or else it would sound anemic. Since TT is known to have a fat and full sound I believe you are able to run them fullrange if you're in to that minimalistic thing (but then the 12 incher probably is a better choice). Personally I would opt for a high pass in the lower spectrum, not as high as 300 Hz though, but some kind of bass taking over lower down none the less..

That's my two cents, for what its worth - I haven't actually auditioned the TT yet y'know

Cheers!

[nullspace]

I see the 10" driver has a couple dB lower efficiency, so maybe this is easier to couple with an OB woofer? I understand the point of an active woofer though.

These compression drivers all have extremely high spl. Aren't there any tweeters that can match the TT without using an L-pad? Any special reasons for choosing compression drivers and horns? Are these known to match well with big widebands?

You're correct, the lower efficiency would make it easier. I would encourage you to find a copy of MathCAD and then pony up the $25 or so to get MJK's OB worksheets. You can find them here: http://www.quarter-wave.com/. Very helpful in figuring out what will and will not work on an OB.

For the 12", I don't know of any non-horn that will work. Also, as you get into this a bit more you'll find that most compression drivers on a CD horn will have just enough sensitivity to match up. That's because on an OB you're looking at ~100dB/1W with the TT 12" and CD horns have a falling response. Typically, 1" compression drivers are up around 107db at 2khz but decline from there to, say for the Beyma CP380M, to 98dB/1W at 16khz. So, no l-pad but instead a notch filter to eq the response.

Thanks, did you perform a freq response curve?

I have one, but I'm not confident enough to post it. Lynn has posted one, linked to above. FWIW, mine roughly matches his. Once I have something a little more sturdy I'll post it.

Regards,
John

 

[ttan98]

For the 12", I don't know of any non-horn that will work. Also, as you get into this a bit more you'll find that most compression drivers on a CD horn will have just enough sensitivity to match up. That's because on an OB you're looking at ~100dB/1W with the TT 12" and CD horns have a falling response. Typically, 1" compression drivers are up around 107db at 2khz but decline from there to, say for the Beyma CP380M, to 98dB/1W at 16khz. So, no l-pad but instead a notch filter to eq the response.
 

I am using B&C DE250 with RCF horn H100, I was to get away without equalizing. If you are fussy with the response some equalization is required. H100 costs $28 each and De250 about $110.

Otherwise you may want to use Gedlee waveguide, no equalization is required as far as I know. FYI it is not cheap in excess of $150. A cheaper alternative is DDS Eng 1-90, about $99, here no equalization is required as well, I heard good reviews about this horn.

[iON]

These compression drivers all have extremely high spl. Aren't there any tweeters that can match the TT without using an L-pad?

If you don't like use of L-pads, (some believe they are evil ) you can attenuate the tweeter using a tapped inductor as done in the LS3/5A for example.

Regards,
Jon

Sidenote: (for those who don't know it already) LS3/5A was/is a famous BBC monitor

[nullspace]

Otherwise you may want to use Gedlee waveguide, no equalization is required as far as I know. FYI it is not cheap in excess of $150. A cheaper alternative is DDS Eng 1-90, about $99, here no equalization is required as well, I heard good reviews about this horn.

A while back, Dr. Geddes posted the crossover for the Summa over at diyAudio, and he does use CD equalization. If you want, I can email it to you.

Regards,
John

[ttan98]

active or passive? email me please. thanks

[painkiller]

Lots of interresting information here. I'm working on getting some simulation software, mathcad and orcad and some worksheets. Still unable to get in touch with A Brown though. Have tried every e-mail adress and contact form, but no luck. 

I'm thinking that this tweeter http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=297-400&FTR=RT1C-A&CFID=27871383&CFTOKEN=64053518 could match the 10" driver in SPL and with decent response to 20Khz. Question is if there'll be mismatch in sonic signature?

So with crossoverless 10" TT's, tweeter with 1st order crossover at somewhere between 8 and 10kHz and then eq the whole thing for a flat response and add an active woofer. Could it work?

[Graham Maynard]

Hi Painkiller,

What about the respective driver sensitivities - is the tweeter sensitive enough for the TT when it is being run with direct connection ?

Cheers ........ Graham.

[JoshK]

nullspace is right, Dr. Geddes uses CD equalization (passive).  As with all CD horns/waveguides, they need equalization, which is easily added into the passive xo if designed appropriately.