Dallas II - World-Designs-Forum

Andrew · #1 13th January 2007, 11:38 AM

Scott mentioned this cab as a possible candidate for an FE208EZ.

It fits my bill, not too wide, good sensitivity and reasonable looks.

I was thinking of fitting the super tweater in the void above the main driver.

I assume 12mm hardwood or birch ply is the ticket?

What should be thinking of to fill the voids? Wadding I assume?

Not sure which tweater yet.

My first step would be to a set of plans, including adding the tweater, a smoother curve on the mouth. This would then give me a curtting list etc.

Any other things I should be thinking about, if I were to go ahead...tho' I hoping to hear this driver next weekend and after that all plans may change.

cheers,

-- Andrew

Scottmoose · #2 13th January 2007, 09:21 PM

Possibly the finest cabinet for the FE206E on the planet, and should take the FE208ESigma happily enough. You wouldn't believe the kind of detail Ron went to in designing his horn enclosures, even though they look fairly innocuous.

I'd fill the voids with something a little more substantial than wadding. Concrete, loads of caulking of expanding foam would be more the mark. Build material should ideally be 18mm Baltic Birch ply. Don't go for thinner as the panels will be far too resonant. Putting the tweeter in the cavity above the driver makes a lot of sense.

pete2112 · #3 13th January 2007, 11:37 PM

I built a pair of Dallas II a while back and am using Fountec Neo CD2.0 ribbons which sound good to me. The voids are filled with expanding foam (can be a bit messy if you put to much in) and 18mm birch ply was used.

Peter

Andrew · #4 14th January 2007, 10:30 AM

Thanks, Pete, what's your evaluation of them - soundwise? What amp do you use? Di you find then good on rock? Classical, jazz etc?

cheers,

-- Andrew

pete2112 · #5 14th January 2007, 11:38 AM

Soundwise they are very good i listen to anything from clanad to motorhead they just get on with playing music. They dont need a lot of power, mine are driven by a 1.5w OTL valve amp.

The plans you have got are for the Fe206e version there are a couple of extra parts for the Fe208EZ, they make a big difference to the sound. I've recently upgraded mine from fe206e to fe208ez definitely worth the extra.

fergs · #6 14th January 2007, 12:07 PM

greetings Andrew. definately use 18mm ply and fill the voids with DRY sand or kitty litter(which is what I did) The horn build isn't the easiest but well worth it. I couldent live with the 206 (to fatiguing for my taste)as I found them too forward and went to Visaton open baffle(absolutelt stunning). I imagine with the 208ez the presentation would be a lot more smoother
peace and goodwill fergs

Scottmoose · #7 14th January 2007, 04:17 PM

206 massivley improves with phase plugs, which take that rising response, (which causes the fatigue), down, and smooths the sound. Kills the midrange resonance caused by the hollow pole-piece too & improves detail. The B200 also has that rise, but in OB apps, it's less noticable. Phase plugs will bring substantial improvements in the Visation too though BTW. The 208 is much smoother than either IMO as-is & has better LF weight (not that the other two are lacking in this respect).

Andrew · #8 14th January 2007, 04:28 PM

Quote:

Originally Posted by pete2112

Soundwise they are very good i listen to anything from clanad to motorhead they just get on with playing music. They dont need a lot of power, mine are driven by a 1.5w OTL valve amp.

The plans you have got are for the Fe206e version there are a couple of extra parts for the Fe208EZ, they make a big difference to the sound. I've recently upgraded mine from fe206e to fe208ez definitely worth the extra.

Hi Pete,

Do you know where I can get the 208EZ plans from?

cheers,

-- Andrew

SimonC · #9 15th January 2007, 01:39 PM

Hi Scott,

While searching the net I have also come across a Dallas III (just photo's, no plans).

Can you give us all a quick summary of the different versions?

Thanks

Simon C

Scottmoose · #10 15th January 2007, 02:59 PM

Hi Simon

Basically, Dallas was Ron's original BLH. DallasII is a heavy refinement of the Dallas, incorporating modifications to the chamber and initial flare. Ron is big on smooth radii in horns for most efficient energy transfer, hense the reason for the multiple small plates he uses to smooth the air-flow. One of his builders went one better a little while ago, and had a DallasII partially cut on CNC machinery, and for other parts bending the plywood to shape, allowing him to preserve a perfect curve throughout the enclosure. That's what became known as DallasIII. As the design itself is no different to DallasII, aside from the smoothing applied, I don't think any detailed plans were made, other than the very basic one I've attached, plus a photo showing the smooth curve the CNC cutting and bending of materials allowed.

Cheers
Scott