Full Range Drivers

Darkmoebius, does your kit have the Fostex Bullet Tweeter? What does putting that kit together entail?

Well, all I can say is that there is an exceptional single driver made by Feastrex that can be used to cover from about 60 Hz to well above 20K Hz. Actually there are two different drivers, one 5" and one 9." The 5" is the better driver and especially in the field coil version. I heard it in the Maxhorn cabinet and was thoroughly please except below 60 Hz. I have spent a good part of my audio life trying to mate subwoofers with such "not full range" speakers. I don't think it can be done.

These drivers are very expensive. I think $39k per pair. I cannot imagine anyone buying them at that price.

Yep, Donjr, I have Fostex FT17H Horn Super Tweeter and the original Audax tweet that came with the kit.

As you've probably already read, the 98.5dB Fostex more closely matches the Super-12's 97db efficiency and only requires minor padding down to integrate well. On top of that, it actually sounds better.

01-27-10: Donjr
Darkmoebius...What does putting that kit together entail?

Darn, I used to have a .pdf copy of the manual on my computer, but I cannot find it. The printed manual is in the kit box in storage.

Essentially, you need only 2(or 3) pieces of 4'x8' mdf wood, wood clamps/straps, table saw, wood glue, and some screws. A router(and roundover but) is best for the port hole and driver cutout, but they can be done with a jigsaw. The speaker plans are designed so that all panels and bracing come off the 2 sheets leaving no real scrap. So, you cut the 4 side panels and two top off each 4'x8' along with 4 1"-2" strips for vertical corner bracing/screw in.

I'm not real good with a table saw, so I spent a lot more time stressing over getting straight cuts than need be. But, it really didn't take that long once I got going. It probably took me an hour or two to trace out and make the cuts, including the port hole and driver cutout. Assembly after that is pretty quick if you've got clamps and/or wood straps to hold the cabinet together while the glue dries.

Some people added extra thin strips of ebony(?) strips diagonally across the largest panels to break up and tame resonances. I added Deflex sound panels in mine behind the 12" driver to absorb and break up reflections from the back of the driver off the back wall. Also some Wispermat on the walls(not completely covered). Both these products absorbed reflections AND deadened the panel resonances. Also, the plumbers putty on the speaker spider. This brought a much higher level of refinement to the sound.

I think I still have 2 extra Deflex pads to go with the kit.

darkmoebius900 posts01-20-2010 3:14pmOne thing that should be made clear is that "Full Range" is a bit of misnomer for the average listener of moderate income and room size. Very, very, few speakers of any driver design actually cover 20Hz-20kHz(-3dB) accurately. Very few do 30Hz(-3dB) accurately. Those that do are usually very big, very heavy, and very expensive.

Fullrange single drivers have their advantages and limitations. I think the first sonic benefit that most fans, like myself, will tout is their musical "coherence". What does that mean? That the entire musical spectrum seems to emanate from one, seamless, sonic tapestry without any inconsistencies. It's very hard to describe in words, but once you hear it, it is very hard to accept anything else.

Why do they seem more "coherent" to some people than other multi-driver designs? I think most of us, like Macrojack, will cite no, or 1st order, crossovers and no need to transition between differing drivers at the crucial midrange frequencies where the ear is most sensitive to anomalies. Seamless transition between drivers of different size and construction materials is not easily done and fairly rare.

The downsides - like all speakers, bass. There are only three ways to deep, accurate, bass; 1) large driver surface area, 2) long driver excursion, 2) big cabinet. Usually, two of the three are necessary unless lots of power is needed.

And single drivers generally need really large cabinets to go deep with any authority. Even then, they won't move the same amount of air as good multi-driver designs. But, well-executed designs will have very fast and clean bass, which can be supplemented by good subwoofers.

Which brings us back to - is that really a single driver system? No, not in the strictest sense. But, single driver advocates are primarily concerned with a driver covering the most critical section of the frequency range in it's entirety - the full midrange (400Hz-6kHz). Most single driver proponents would even like to push that out to 8kHz-10kHz.


~~~~~~~~~~~~~~~~~~~~
The earlier Full range/wide band/high sensitivity speakers did lack fq extention in bass and highs.
This is correct.
Starting cerca 2010, time of your post, there were 2 new labs making single  wide band drivers that were developed to correct these limitations.
These mew kids on the block now boast bass and highs.
So if we consider these new developments, then Wide band single drivers are superior to any speaker witha  xover. 
as we all know xovers get in the way of the original musical source. Its a **add on** and causes depletion of energy = efficiency = enter in distortion. 
Besides  the xover variety in order to acheive FULL fq extention, requires drivers that handle bass, midrange and highs. 
Not as easy as it sounds. 
Bass, yep, got that. Mids,,hummm, issues here, Highs, again, issues. 
To attempt all 3 witha  xover, = big heavy speakers and very expensive.  +  by gaining rock solid bass and some high fq;s, you end up with so-so midrange.
Lets consider darkmoebius final comment.
**But single driver advocates are primaarily concerned with a  driver capable of covering the ~~MOST critical section~~~of the fq band ~~in its entireity~~~The Full MIdrange , 400hz-6khz,,,

Very nice assessment from darkmoebius.
This is pretty much what we , wide band fan-atics are after in a  speaker. Voicing midrange with clarity, presence, lowest distortion as technically possible.
And if bass is there, = bonus, 
Highs are there = yet another bonus.
We are not after the ultimate FULL Range.
We are only after the  midrange section. 
Nothing more.
Here is where most xover designs fail. The mids always have issues,. 
Of course the xover fans don't want to hear what I hear. 
At least when it comes to challenging music genres, 
As i full symphony orchestra. 
Any weaknesses in mids , while trying to voice a  full symphony orchestra, these weaknesses will most certainity, will surface. 
I can hear this liability, they can not. 
We have 2 camps, 
'The xover/inefficient  camp, And the wide band/high sensitivity  camp.
The very best xover speakers are comming out of Troel Gravesen's lab. 
Not cheap, these are super high end and as i say, bring your AMEX Gold card, you will need it. 
These TG's are the very best of the best in xover designs. 
Hats off to Troels,  guy is a  genius  in choosing drivers and xover components.  Nothing 2nd rate in his speakers.
But now along comes the new high tech wide band drivers to match what Troel's is accomplishing with xover designs.
. But the wide band is more suited for my musical taste and budget. 
Not to mention speaker size/weight. 
Troel's speakers tend to be rather large and heavy.  
The new wide band as i see it ..is a  
~~Win-Win-Win~~ speaker set up. 
vs xover designs. 

darkmoebius900 posts01-28-2010 2:03pmYep, Donjr, I have Fostex FT17H Horn Super Tweeter and the original Audax tweet that came with the kit.

As you've probably already read, the 98.5dB Fostex more closely matches the Super-12's 97db efficiency and only requires minor padding down to integrate well. On top of that, it actually sounds better.

01-27-10: Donjr
Darkmoebius...What does putting that kit together entail?

Darn, I used to have a .pdf copy of the manual on my computer, but I cannot find it. The printed manual is in the kit box in storage.

Essentially, you need only 2(or 3) pieces of 4'x8' mdf wood, wood clamps/straps, table saw, wood glue, and some screws. A router(and roundover but) is best for the port hole and driver cutout, but they can be done with a jigsaw. The speaker plans are designed so that all panels and bracing come off the 2 sheets leaving no real scrap. So, you cut the 4 side panels and two top off each 4'x8' along with 4 1"-2" strips for vertical corner bracing/screw in.


~~~~~~~~~~~~~~~
Yes this is yet another huge advantage going single wide band driver.
I am on a  tight audio budget,  lately, and so making a  DIY cabinet works for me. 
I plan to make a  temp cabinet, just to get the driver up N running, later on I'll work on a  more complex proper enclosure, taking my time with the cuts and details. 
I'm about tired of this  4 inch wide band ~~made in china~~ driver. Its ok, not worth any more than I paid for it = $175/pair. 
But better for classical than was the Millennium tweeter, at 87 db, THATS FOR SURE!!
I like to use 1/2  inch sanded plywood when building a  cabinet. 
= Lighter and more easy to work with vs 3/4 inch.