FR125S in TL?

[audiobomber]

Originally posted by planet10
One could go a step further and make a triangle (or pentangon or hexagon) shaped column and load 2 STs on the back.

Aside from reduced standing waves, what benefit would there be to a triangular column with a pair of ST's vs. a rectangular bipole with a single WR125S?

[GM]

Originally posted by planet10
If you are going to port the FR or WR125 (and not make them aperiodic) i suggest a high pass filter to keep any signal from getting to them in the area where they are unloaded -- otherwise they will "fart" when that signal causes them to bottom out.

Our feeling after the event is that one should avoid tuning these too low (ie the GM pipes are going under the saw to become shorter, and the tuning will be raised.

dave

Greets!

Not surprised since they apparently don't have a typical FR's rising rate suspension and low enough efficiency to tend to overdrive them, but I fail to see why shortening them/tuning them higher helps since all this does is unload them higher up, forcing XOing to a sub instead of just a 'rumble' filter to roll them off below Fb.

Also, this raises them into an underdamped alignment unless they are made aperiodic, which FWIW I prefer to sealed to keep thermal power compression low while negating the need for a high pass XO, so I'd rather damp the vent of the full size ML-TL than put it in a smaller cab.

GM

[planet10]

Originally posted by GM
Also, this raises them into an underdamped alignment unless they are made aperiodic, which FWIW I prefer to sealed to keep thermal power compression low while negating the need for a high pass XO, so I'd rather damp the vent of the full size ML-TL than put it in a smaller cab.

We ended up stuffing the ports of all the WR/FR boxes to push them toward aperiodic. The shorter lines seemed to work better even after.

I'm going to be concentrating on aperiodic designs as we move forward -- i will also rig up a high pass filter & see how that works out.

dave

[planet10]

Originally posted by audiobomber
Aside from reduced standing waves, what benefit would there be to a triangular column with a pair of ST's vs. a rectangular bipole with a single WR125S?

probably no advantage (HF wouldn't be firing straight back & would be more dispersed thou). Bob would be happy selling 6 drivers instead of 4 thou

dave

[GM]

Originally posted by planet10


We ended up stuffing the ports of all the WR/FR boxes to push them toward aperiodic. The shorter lines seemed to work better even after.

I'm going to be concentrating on aperiodic designs as we move forward -- i will also rig up a high pass filter & see how that works out.

dave

Greets!

That's surprising! I guess it's a consequence of a relatively 'stiff' suspension (small Vas) since I didn't find this to be true with what we now call 'vintage' drivers.

Alpha TL tuned to 1.4142*Fs then?

GM

[planet10]

Originally posted by GM
Alpha TL tuned to 1.4142*Fs then?

Was thinking about alpha TLs when i was out driving into town today (your inspiration )

dave

[audiobomber]

Originally posted by planet10
probably no advantage (HF wouldn't be firing straight back & would be more dispersed thou). Bob would be happy selling 6 drivers instead of 4 thou

dave

I already have the drivers. I just need a good plan for what to do with them.

[tcpip]

Originally posted by audiobomber
They're paper cones. The specs are on the CSS site, but I couldn't find them, even though I knew they were there. I had to Google for them. (Are you listening, Bob Reimer?)

Thanks. But guess what? I'd already found the specs (at least some specs) on Dave's site (Planet10) before I saw your posting. I said "some" because those specs only contained drawings, dimensions, and T/S parameters. Not a single line on the construction, technologies, distortion-reducing measures, nothing. For drivers this good, I'd have thought lots of such details would be justified.

Oh yeah! They have very good resolution, they allow you to use shallow slopes and wide XO points, and they don't need a notch filter. All good things IMO.

Yes, those are very tempting qualities. Two more questions:

• Will they be as detailed as good hard-cone drivers, assuming that careful notch filtering is done to remove peaks for the hard-cones? I'm thinking of SS carbon-fibre cones or Seas Excels.
• How do these compare with 6-8" sized Fostex drivers?

Mind you, I'm interested only in using both as wide-range mids in boxed or OB 3-ways, not as FR drivers. Hence, HF distortion in one or other of these above, say, 8K, doesn't concern me if I can get things clean from about 200Hz till 5-6KHz.

I've been toying with using some good FRs as mids for a long time, and I'd have happily used JX92S all the way for such roles if I could afford them. So I'm now looking around for alternatives.

Originally posted by Bob Reimer
Apologies, I have added the links with the item. A redesign of the website is planned.

Can I make a suggestion for your otherwise excellent site? Please can you link each product from their details page to a spec-sheet? At least can you do this for each of your kits and drivers? Currently the detailed pages which come if I traverse after a search just contain one small photo, a one-line description and the price. A link to the detailed specs from here would be really useful.

Just a suggestion, feel free to completely ignore.

[audiobomber]

Originally posted by tcpip
Not a single line on the construction, technologies, distortion-reducing measures, nothing. For drivers this good, I'd have thought lots of such details would be justified.

See the bottom of this page for a couple of papers on Adire's XBL technology: http://adireaudio.com/TechInfo.htm

Will they be as detailed as good hard-cone drivers, assuming that careful notch filtering is done to remove peaks for the hard-cones? I'm thinking of SS carbon-fibre cones or Seas Excels.

I don't have experience with the drivers you mention. I know that some people prefer paper cones and some prefer hard cones, so I guess it depends on your preference. I know that I've used notch filters with my Marchand crossover and IME they mess the sound up. I also dislike 4th-order crossovers, so I would not use a hard cone. YMMV.

How do these compare with 6-8" sized Fostex drivers?

You'll get very poor dispersion from a 6 or 8" cone at 5-6K. The WR125S will be very good from 200 Hz to 5K.

PS I think the SS carbon-fiber cones you reference are actually carbon-impregnated paper cones.

[zobsky]

Originally posted by GM


Alpha TL tuned to 1.4142*Fs then?

GM

I tried that (though I folded the line) , .. wasn't happy with the bass I was getting (though it is possible that I goofed up )

I was happier with a MLTL (similar to Tim Forman's Rosa) using two WR125s drivers per cabinet.

Thanks GM, for your help