FR125S in TL?

[robertG]

OK, these were great on OB, but my room is simply too small. Did anyone tried a TL with these?

I started to read Martin King excellent material on TLs, and got an equally excellent headache... I mean these things are harder to figure out than horns...

So, out of laziness, I'm trying to find something fast, easy and proven.

From what I understand, a properly designed TL will be nicer than any BR, but a badly designed TL will be worse than a bad BR...

[MikeR]

From a previous post by GM on this driver.....

Greets!

A basic end loaded (Alpha) TL, nice midbass, ~75 Hz aneochoic F3, ergo requires a corner for ~decent bass:

L = 32.03"
CSA = 47.047"^2
stuffing density = ~1.75 lb/ft^3

45 Hz ML-TL, smoothest sim (~+/- 1 dB), but requires either a stand or a mass loading cavity to get the driver to ear height:

L = 39.56"
CSA = 43.68"^2
driver down 14"
vent = 3" dia. x 3" near/at the bottom
stuffing density = ~0.3 lbs/ft^3 from top down ~30"

45 Hz ML-TL, driver at ~ear height (~+/- 2 dB):

L = 39.56"
CSA = 43.68"^2
driver down ~3.3"
vent = 3" dia. x 3" near/at the bottom
stuffing density = ~0.3 lbs/ft^3 from top down ~30"

All dims inside and use stuffing in the bottom portion of the ML-TLs to 'tighen up' the bass to get a better blend in-room if desired.

Anybody builds any of these, please report back.

GM

[robertG]

Forgive my ignorance, but what's CSA? Is it the area?

[Jim Griffin]

Robert,

CSA = cross section area

If you wish to take the mystery out of these numbers, just go to this site for my version of GM's design:

http://www.planet10-hifi.com/boxes.html

Click on the photo of my speakers or go directly to:

http://homepage.mac.com/tlinespeaker...LDesignPak.pdf

This design is highly recommended.

Jim

[planet10]

Just on Saturday we got to listen to a number of ML-TLs with FR & WR125s.

A GM ML-TL (driver down 14"), 3 variations on the bipole i designed based on Tim Formans WR TMM, and a shorter Tim Forman bi-pole.

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

[tcpip]

Originally posted by planet10
Just on Saturday we got to listen to a number of ML-TLs with FR & WR125s.

Where does one find some specs of these drivers? I went to the page for the WR125 on the Creative Sound site but there were no specs at all. Are these metal-cone?

And these WR drivers should be very good as wide-range mids in 3-ways, shouldn't they?

[audiobomber]

Originally posted by planet10
3 variations on the bipole

Has anyone tried a WR125ST (16-ohm) as the rear driver in a bipole? I'm thinking it might give some of the benefits of a bipole and lessen the bipole effect (not as focused as a front-firing system?).

I just took delivery of a pair of FR125S's yesterday and plopped them in my RAW-1F in place of the WR125S's. Wow! Quite the improvement. I also played around with my Marchand XM44 crossover for the first time in comparison to no crossover (FR125 running full range in a 7L aperiodic cab, with dual subs at 100HZ). In the past I've only compared the Marchand to passive crossovers, and it always won easily. But compared to no crossover, it's clearly compromising my Meitner amps. So I've suddenly become highly interested in this bipole idea.

[audiobomber]

Originally posted by tcpip
Where does one find some specs of these drivers? I went to the page for the WR125 on the Creative Sound site but there were no specs at all. Are these metal-cone?

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?)

http://www.creativesound.ca/pdf/wr125-dimensions.pdf

Originally posted by tcpip
And these WR drivers should be very good as wide-range mids in 3-ways, shouldn't they?

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.

[CSS/XBL]

Apologies, I have added the links with the item. A redesign of the website is planned.

Bob

[planet10]

Originally posted by audiobomber
Has anyone tried a WR125ST (16-ohm) as the rear driver in a bipole? I'm thinking it might give some of the benefits of a bipole and lessen the bipole effect (not as focused as a front-firing system?).

Bob suggested that really early on to me. I don't know that anyone has tried it yet. It should work to decrease the amount of baffle step compensation. One could go a step further and make a triangle (or pentangon or hexagon) shaped column and load 2 STs on the back.

dave

PS: the spec sheet is also on my planet10-hifi site