[tahoerog]

Question: Very weak volume from the 5 dome tweeters
I am re-foaming my super tower IIa s which I bought in kit form from Brian many years ago. They are in great condition.
The dome speaker wiring seems to be correct and follows the same pattern for each of the other speaker groups (series/ parallel) which calculates out to be about 6.9ohms for the dome  tweeter circuit.
The dome tweeter adjusting pot was bypassed and does not seem to be the problem.
All the other speakers work great. I did not check the capacitors on the dome tweeter circuit yet, but I don't think that is the problem.
Has anyone else had a low dome tweeter issue or is it a design issue?
Thanks in advance,
Roger

[James Romeyn]

Question: Very weak volume from the 5 dome tweeters
I am re-foaming my super tower IIa s which I bought in kit form from Brian many years ago. They are in great condition.
The dome speaker wiring seems to be correct and follows the same pattern for each of the other speaker groups (series/ parallel) which calculates out to be about 6.9ohms for the dome  tweeter circuit.
The dome tweeter adjusting pot was bypassed and does not seem to be the problem.
All the other speakers work great. I did not check the capacitors on the dome tweeter circuit yet, but I don't think that is the problem.
Has anyone else had a low dome tweeter issue or is it a design issue?
Thanks in advance,
Roger

Roger,
"Very weak" is vague...do you mean comparing one channel to the other or what? 

An L-pad is not a pot though it looks like one.  It's an impedance matching device with two pots, one in series and one parallel.  A plain pot would cause the pole to change with rotation. 

What does "bypassed" mean?  (Clear image or draw schematic please.)  Brian would absolutely never in a million years "bypass" an L-pad.  A "bypassed" L-pad then not being an OEM design, it's wrong to discuss "design issue" relative to treble on this speaker.   

Brian's tweeters are generally crossed an octave higher than normal practice because he abhorred low pass mid range crossover (finally changed about ten years prior to his passing).  Brian emulated Richard Heyser's crossover design principals and he presumed Hyser would disapprove of mid range low pass crossover.  Anyway, the higher than average crossover pole can be mistaken for low overall output.  What domes are these, Morel D29?  Five per speaker?

Get a cap meter, open one end of the tweeter cap bank, and measure.  Estimate 3.0mF IIRC (should be written on one of the caps in the bank with a Sharpie or refer to wiring instructions).         

[ZAKski288]

Hi  DBs.  I own a pair of Supertower/R, have done numerous driver and crossover upgrades as well as refoams.  I have schematics that I can copy and send to you if you wish.

Your rehab will come down to how much time and money you want to spend.  New drivers are an easy and more expensive fix and give better performance.  Most likely the drivers you have now can be refoamed and used.  A cheaper alternative, will  get the speakers working but not to the level of new drivers.  Your choice.

You can try refoaming the 12” driver and 15” passive.  From what I can tell from the picture the 12” cone looks to be creased in some places which could affect performance.  Are the cones on the passives disconnected?  I had to replace mine because they dry rotted to the point where the cone came off the driver body. 

Gently run your finger around the foam surrounds of all the drivers.  If they crack or crumble they need to be refoamed or replaced.

I have two 12” original drivers for sale.  See my recent post.  They have been refoamed but work fine.  Let me know if you are interested.  Not the latest technology but an inexpensive alternative.

Being a Supertower/R (and Tower ii) owner I am biased and would suggest keeping them and getting them working to your satisfaction.  You will be pleasantly surprised when you hear them.

Cheers!
Ed (ST86)

ST86   I to just recently purchased a pair of VMPS Supertower  /R  and need to go threw them, if possible can I get a copy of the schematics. enclosed are some pictures unloading, and yes they both fit in the back of my Pruis no problem. The guy was amazed they fit. Thanks Ken

[ST86]

Hi Ken,

PM me your address and I will be happy to send you a copy of the schematic.  Be warned the crossover values shown are for original drivers.  Looks like you have updated drivers.  I have many of those same updated drivers.  I'd be interested in what you find regarding wiring and crossover component values, especially the L and C values for the woofers and midrange.  I ask the favor that you update me when you open them and review the internal wiring and components. 


Regards,

Ed

[davidc1]

From your description, and the photo, the part you are talking about is the TOGGLE SWITCH that joins the WOOFER Section and the Tweeter/Midrange Section for single amping, or separates them for bi-amping.

I talked Brian into doing away with that TOGGLE and we just jumpered the binding posts if we wanted to single amp.

I had experimented and found that "jumpering" was sonically superior.

Sorry this is so old, but...

I had heard in the past that the toggle switch seperated the woofer and mids, from the tweeters. Yet you said it seperates the woofer, from the tweeter and mids.

Which is actually correct?

I have a 1980 pair of Super Towers I built from a kit and upgraded in 1988. I want to bi-amp  them now since I have two identicle amps, but from a power standpoint it would be much more effective if one amp powered the woofers, and the other powered the mids and tweeters.

So which seperation is actually correct?

Thanks very much.

[John Casler]

Sorry this is so old, but...

I had heard in the past that the toggle switch seperated the woofer and mids, from the tweeters. Yet you said it seperates the woofer, from the tweeter and mids.

Which is actually correct?

I have a 1980 pair of Super Towers I built from a kit and upgraded in 1988. I want to bi-amp  them now since I have two identicle amps, but from a power standpoint it would be much more effective if one amp powered the woofers, and the other powered the mids and tweeters.

So which seperation is actually correct?

Thanks very much.

Hi David,

You know when we're talking about Brian, ALL THINGS are possible, since he played fast and loose with changes to a specific speaker and made changes on the fly.  Since directly amping a tweeter can be VERY TRICKY (as in don't blow it up) I have my doubts he ever did such a design.

However, in general the toggle was to separate the Woofers from the Mid/Tweets as in most biampable designs.

I mentioned to him that using the toggle seemed less open and clear and that why couldn't we just "jumper" the binding posts.

He agreed, and obviously it made fewer parts, less circuitry, and an easy solution.  We even started including the O-ring Analysis Plus wiring jumpers with each speaker.