[tanchiro58]

Thanks John,
I was waiting for a response from you.
My system is active PC XO + EQ so i can 'perfect' any ugly duckling.
If you say they are junk your word alone is enough for me.
I guess there is no denying it, i have to go with Augies!

Ohh man this is SO dangerous if I go to THAT web site I might 'accidentally' order SI Coax to try them too. And i JUST got my B200 a week ago.
Little OT:
I'm afraid of the harsh sounding crossover point between 15" and horn tweeter in SI coax. B200 has better mid response.

BTW John how are our experimentation with Ringed baffle that you mounted directly to B200 (stack of rings equivalent of 18" baffle)?
How does it sound? Would you go back to regular baffle?
I'm very interested in the design i might do that with a matching Ringed Augie underneath it (both magnet mounted of course).


If it doesn't sound too good then i might do do something similar to your other baffle only 40" tall:





Thanks for all your help, experimentation and for sharing it with us!

Hi Everyone,

These are very nice OB I have never seen.

I am Newbie in this thread and plan to build an OB speakers with anilco magnet Stephen Trusonic 12" woofers and JBL 375 Horn/tweeters lying around. Have anyone tried building this before? Any opinions and suggestions would be appreciated. Thanks in advance.

Cr_otmopo3ok,

Based on the nice pictures do you have any dimensions of the wooden frame in details? Thanks.

Best regards,
Tan

[iON]

If you click on tech data for another relevant pdf on this page there is a response chart which looks as though the vertical scale was compressed, although close analysis shows the same scale, I think. Puzzling - this one is much more flattering.

Puzzling? Not at all. One graph is directly from the vendor while the other one isnt. A good rule of thumb is that graphs from vendors should be taken with a grain of salt (tm). In this case the graph is cut at 60 dB (Showing 10 dB less) effectively removing most of the breakup region, and one can also see that they've applied some octave smoothing to make it even more "flattering".

Let me by the way be clear that I consider the response to look fairly normal for a pro 15 incher and not bad at all. Conebreakup doesn't look to nasty, it is fairly linear with no crazy dips or peaks. For comparison, have a look at the Eminence Alpha (that's been used in many succeful builds!), it has a rough peak (+10 dB !) between 2kHz and 3 kHz. http://www.prodance.cz/protokoly/alpha_15a.pdf

Rgrds,
Jon

[Russell Dawkins]

If you click on tech data for another relevant pdf on this page there is a response chart which looks as though the vertical scale was compressed, although close analysis shows the same scale, I think. Puzzling - this one is much more flattering.

Puzzling? Not at all. One graph is directly from the vendor while the other one isnt. A good rule of thumb is that graphs from vendors should be taken with a grain of salt (tm). In this case the graph is cut at 60 dB (Showing 10 dB less) effectively removing most of the breakup region, and one can also see that they've applied some octave smoothing to make it even more "flattering".

Let me by the way be clear that I consider the response to look fairly normal for a pro 15 incher and not bad at all. Conebreakup doesn't look to nasty, it is fairly linear with no crazy dips or peaks. For comparison, have a look at the Eminence Alpha (that's been used in many succeful builds!), it has a rough peak (+10 dB !) between 2kHz and 3 kHz. http://www.prodance.cz/protokoly/alpha_15a.pdf

Rgrds,
Jon

Yes, I am aware of smoothed manufacturers' graphs!
I don't think the 60 dB cut off vs 50 dB is significant - 50 dB is a long way down, but closer inspection reveals that the graph you linked to is taken at 1 watt, whereas the Selenium published graph is at 10% AES input power, or 25 watts. The published power compression at that power is .6dB.

This, plus inherently different response curves at different output levels, would affect the outcome more than smoothing, which I can see through to an extent.

I imagine that the test procedure was quite different, because the differences go beyond scaling and smoothing.

Anyway bottom line is listening and apparently this driver passes that test with flying colours, according to those WEIT (whose ears I trust).

Add to that good sensitivity, appropriate qts, high power handling and reasonable tariff and that is why I brought it up!

[JeffB]

I asked this last year without an answer, so I think I will try again.

This link shows the graph for the Selenium 15"
http://www.iakn.com/PDFs/15PW3_i.pdf

This link is to the tone tubby speaker list.  Click on the 8ohm specs for the Tone Tubby 8".
It will bring up a spreadsheet with a graph and specs.
It is the only Tone Tubby you can get specs on.
http://www.tonetubby.com/speaker.htm

The Selenium 15" graphs drops straight off a cliff below 90Hz.
The Tone Tubby 8" graph hangs pretty flat until 50Hz.
For $90 I am seriously thinking about a Tone Tubby 8" for bass duties.
However, the physics of it just don't make sense to me.
How can a smaller cone with less xmax have deeper bass?

[scorpion]

Jeff,

In OB the Tone Tubby 8" will play less bass than a Visaton B200 fullranger. Tone Tubby has an X-max of 1.9 mm the B200 has 3.5 mm.
It will reach X-max at about .6 watt.

/Erling

[iON]

Anyway bottom line is listening and apparently this driver passes that test with flying colours, according to those WEIT (whose ears I trust).

I agree, Listening should always be the final judge. By the way, I like the acronym - WEIT.

[JeffB]

Scorpion, your comment may save me some money which is good.
However, I am still trying to understand the graphs.
The 8" Tone Tubby graphs shows it 
-3db at 50Hz with an SPL of 90.
-6db at 40Hz with an SPL of 87.

The 15" Selenium
-14db at 50Hz with an SPL of 84
-18db at 40Hz with an SPL of 80

A B200
-14db at 50Hz with an SPL of 82
-16db at 40Hz with an SPL of 80

According to the graph the Tone Tubby is the clear bass winner by a long long way.

So what am I missing in the graphs?
I am assuming these measurements are taken on a large or infinite baffle at 1 watt/1meter.

I guess if the Tone Tubby were in a box when measured then I could see how the response would be very different than on an open baffle.
But why would anyone do this.  How would you adjust for baffle step compensation?

I would think the driver would behave the same on infinite baffle as on open baffle, because there is no pressure on the cone from a box.
I understand that the open baffle is going to have cancellation issues, but I would think that if a driver were good in infinite baffle then it would be good on open baffle.

[iON]

I asked this last year without an answer, so I think I will try again.

The Selenium 15" graphs drops straight off a cliff below 90Hz.
The Tone Tubby 8" graph hangs pretty flat until 50Hz.
For $90 I am seriously thinking about a Tone Tubby 8" for bass duties.
However, the physics of it just don't make sense to me.
How can a smaller cone with less xmax have deeper bass?

According to the graph the Tone Tubby is the clear bass winner by a long long way.

So what am I missing in the graphs?
I am assuming these measurements are taken on a large or infinite baffle at 1 watt/1meter.

Hi Jeff!
It's easy to stare yourself blind on measurements. Remember: how much bass you can produce pretty much correlates to how much air you can move.

For example, I know of a guy that have a 3" fullranger in a transmission line pipe that goes fairly flat down to 40 Hz. That is incredible low bass for such a small element. However, it is really limited in how high he can play.

The same applies to the elements mentioned above. A 15 incher has a roughly cone area around 10 dm2 and a 8 incher around 3 dm2. Multiply that by the xmax and you'll get the maximum volume displacement (in the linear territory). Obviously the selenium can move a lot more air then the B200 or the TT. In other words, the TT will "run into the wall" first, then the b200 while the selenium would still have more to give.

Indeed, You _could_ use the tone tubby for bass - If you have very modest requirements on volume or if you used several of them, (For every doubling in cone area you will effectively reduce cone excursion requirement by half),.. but it seems like a wasteful way to use a nice fullranger. 

I think that when dealing with this kinds of stuff it is really useful to do simulations too see if your design meets the desired sound pressure level. Good luck with your continuous efforts!

[scorpion]

I agree strongly with iOn here.

I exaggereated a bit but at 30-40 Hz the Tone Tubby will bottom with less than 1 watt power.
The Selenium 15 PW3-SLF is a very capable unit more so if you feeed it with a 5 ohm series resistor then it will produce in the neighbourhood of Eminence Alpha 15.
But the Eminence is a very good unit to use as it is in quite different circumstances, see this new paper by MJK: http://www.quarter-wave.com/OBs/OB_Theory.html .

Good Luck !

/Erling

[Dmason]

I think where the Tone Tubby 8 should be examined VERY carefully is in use as a midrange driver that happens to be easy to integrate with a real bass driver, your choice of 15 incher, all of which will work, some better than others. The 8 looks to me like a bullseye winner of a midrange candidate, which is good apparently to 9KHz, and would very easily work down to 150Hz in my opinion. I would bet that with its dust cap removed and a phase plug installed, many people would be satisfied with it, tweeter optional.

Using the eminenice Alpha, or the Selenium, both of which are known to work, you could be looking at a VERY cost-effective 2 way OB, and if addition of a tweet were essential, it would be easy, and also inexpensive. Dayton has cheepie teensytweets galore, a few of which are similarly sensitive to the Tubby.

Getting abit more involved, and representing far greater potential would be the forthcoming DIY Cable Dipole 15 bass driver with XBL/2 motor, using a larger Hemp Tone cone such as the Eminence Lil Buddy, a 10 inch with Tone Tubby cone, and for a tweet, the inexpensive but reportedly fantastic B&C DE-10 compression driver, and a Dayton waveguide, or one of the small waveguides designed for 1 inch compression units. You could pull in all the components for this build for a tad under $500 making it still very affordable. Using inexpensive switching amps for bass speakers leaves the door wide open in both scenarios for the use of flea amps to power the mains. Now you are into an optimal situation on the cheap. Plate amps become less and less costly, and are much better apparently, than they were a few years ago; SET amps can be had on the cheap, the  Bottlehead SEX amp still amazes me, an extremely good amp for little $. A whole new system using all of the best thinking could be done for under a thousand, and the speakers for very, very little. Exciting stuff.

www.svvintageamps.com   for best prices on Tone Tubby stuff