My take on FR125S in OB

[Rafal]

Hi Folks,

I have just gotten a pair of FR125S from Tom Zurowski (http://audio-resolution.com/zhorn/). Thans Tom for the drivers and huge help!

I spent 4h yesterday putting together OB speakers out of them (approx22"x33") using 5/8" baltic birch ply.

It's my first expierience with OB and It's quiet interesting. The bass get's quiet substential when I put the speakers closer to the wall. When I compare them with my Tannoy Studio 800A, FR125s seem even more detailed and more time aligned. I just wish they had more"weight" to them (they are being driven by a gainclone which I built - middleshelf in a pic). I was intrighued by an idea of Visaton 200A in "Nobox" design and thought about doing something simillar but with FR125s. Has anyone tried it? Any recommendations re. woofer and crossover? I want to run the FR125s wide open.

Any other suggestions on optimizing my current design would also be hugely welcome.

Cheers,

Rafal

[Rafal]

Pic #2

[Rafal]

Pic #3

[maxro]

oooh, I like those multi panel sides on your stereo cabinet.

Sorry, no advice on crossover etc.

What do you mean by time aligned? Aren't both single driver speakers? Maybe the port on the Tannoys causes a phase issue.

Max

[Glowbug]

Pretty speakers!

I haven't tried OB personally, but would like to someday when I get the space to. Apartments do have their limitations :/

[Rafal]

Originally posted by maxro
oooh, I like those multi panel sides on your stereo cabinet.

Sorry, no advice on crossover etc.

What do you mean by time aligned? Aren't both single driver speakers? Maybe the port on the Tannoys causes a phase issue.

Max

Thanks Max,

I built the stereo cabinet too. I'm glad you like it.
The tannoys are dual concentric, so they "kind of" have one driver (it's really 2 drivers, on inside anoter).
By "time aligned" I mean that the FR125s make it easier to follow the melody. More natural that way. Tannoys on the other hand have wider and ruler flat freq. response and a LOT of oomph (2 90w amps(1/driver) and active xo in each speaker). theuy also don't give up much in terms of detail.

[lovechild]

Originally posted by Rafal
[B]I just wish they had more"weight" to them (they are being driven by a gainclone which I built - middleshelf in a pic). /B]

You might want to try increasing your baffle height, I don't have much experience with OBs, but the only OB I heared, that had sounded correct without extra bass support was about 66" x 22" plus two 12" wings - like the ones on the pic below.

cheers
LC

edit: but maybe the FR125s is just to small for OB, mostly they use 8" and bigger...

[2litre]

Rafal,

Nice speakers. Especially in only 4hrs. Kind of like a mix of the classic Japanese design and the NoBox.

I think my FR125's sound beautiful in open baffle too. But they just don't present the punch of a larger driver. Best for smaller rooms, which I happen to have aplenty. I'm looking to add bass drivers too but don't intend to let my FR's run full range. I want to cross them in the range of 125-140Hz.

I've built / used flat baffles, the NoBox and a baffle design similar to the one that lovechild mentioned. To me the NoBox style presented the best sound of the three.

With your FR's offset in the baffle and set low you're on the right track already. Should you end up with a bass driver you may have to build new ones.

A bass driver for the FR125 was sort of discussed in a recent post though OB wasn't specifically addressed. Like the OP of that thread, I'm looking at the Extremis 6.8 or Dayton RS200 in this application.

R/

Jim

[Vikash]

Originally posted by 2litre
With your FR's offset in the baffle and set low you're on the right track already.

Not for the top end. Unless you lie on the floor when listening

[Rafal]

Originally posted by Vikash

Not for the top end. Unless you lie on the floor when listening

I was worried about that too, but I found that the imaging was pretty good and the soundstage didn't seem too compressed to the floor. The treble was very nice and clean.