Frugel-Horn Lite for 3" drivers

Is the Visaton FRS 8 (params below) likely to work in the FH Lite? Anyone modelled it, built one, or willing to guess?

Rated power 30 W
Mean sound pressure level 82 dB (1 W/1 m)
Excursion limit +/−2,5 mm
Resonance frequency fs 120 Hz
Magnetic induction 0,8 T
Magnetic flux 200 µWb
Height of front pole-plate 4 mm
Voice coil diameter 20 mm
Height of winding 4,5 mm
D.C. resistance Rdc 7,2 Ohm
Mechanical Q factor Qms 4,85
Electrical Q factor Qes 1,32
Total Q factor Qts 1,04
Equivalent volume Vas 0,9 l
Effective piston area Sd 31 cm²
Dynamically moved mass Mms 2,5 g
Force factor Bxl 3,2 T m
Inductance of the voice coil L 0,9 mH
 
You know, I don't often say anything like this, but I'm extremely proud of the work Dave, Chris & I have done on the FH series (with hat off to Ron as well for the original curved back & thanks to a few others who prefer to remain nameless for background teaching years before). They really are quite special, on many levels.

Maybe I should give the old British understatement a break more often. :)
 
It has been too long since the last FH Lite build here. These speakers certainly deserve more attention. I have been lurking here for the last 2 years, thinking and planning a FHL build.

So, it just happened that my brother-in-law came seeking my advice a few weeks ago after his crappy sounding music station (MP3, CD, Turn table, speakers combo) stopped working. I suggested a simple and cheap diy solution - maybe a TDA7297 lunch money amp with FHL speakers, since I have a pair of TC9FDs lying around that can be used. I gave him the FHL plans and he was hooked on the idea. Turned out to be a great project - he has a commercial woodworking factory with all the machines and tools needed, and I have the drivers.

It took him only few days to source excellent quality Birch ply (from Russia) and knocked together the boxes. He decided to make the tops (and not the sides) removable, so I had to do the mounting of the drivers and all the damping by working through the opening at the top. Not such a great idea and not recommended, but I managed with great difficulty. I had to play around with the damping and ended with much less than recommended. Final testing done with my TDA amp and they sounded quite good. In the meantime my brother-in-law splashed out and bought a new Marantz amp, a Sony CD player and an Audio Technica turn table. Saturday I delivered the FHLs and we connected everything.

I was a bit nervous about the FHL's performance since they looked so small in his large lounge. But we were all pleasantly surprised with the sound. These speakers play much louder and bigger than you can imagine. Great soundstage, excellent imaging and as someone else remarked earlier - they are very revealing too. My brother-in-law is very happy with the sound and I am very satisfied too. We played Pink Floyd’s Wish You Were Here and could not stop listening. Amazing bass for such a small driver.

Built with 12mm Birch ply and stained to match the oak furniture. In hind sight the staining did not turn out so great and the natural Birch would have looked much nicer. Three layers of ply was used for a base which makes them very sturdy and heavy. Thank you Dave (Planet10) and kie for making this available. My brother-in-law is already asking about the FH3 and FHXLs.

Here are two photos. How they arrived – topless. And fully dressed and doing their first performance.
 

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frugal-phile™
Joined 2001
Paid Member
"woden dunideer"

Dunideer and all the Frugal-Horns come from the same mind. The FH-Lite is a more recent design, and one of Scott’s greatest works (i say that in the sense of the familiy of Frugel-Horns)

The original Alpair 6 used in Dunideer will work in FH-Lite, whereas the new A6.2 may not be optimum for the Dunideer.

dave
 
Dear Dave and Chris, and other friends here,
Following a number of sound advice I've received, I am set on building an FHL for my bedroom. Carrying over another discussion from another thread, Chris suggested diagonal placement ala Decware which I promptly followed :p along with a range of 3-4" designs. I have a pair of TC9FD that are playing inside a pair of Mini-Karlsonators. So I decided to use it for my FHL. I've bought the 12mm ply and a friend agreed to help me do the flare.

In the photo attached, the mini-Ks are playing right about ear level when I sit. The 762mm height of the FHL is where I put the green tape on the stand. Anything I can do to project the sound higher up? I'm already thinking of a front outrigger that raised it without raising the back, as I understand the mouth needs floor reinforcement for bass?

Thank you very much.


The room being almost exactly square doesn’t help matters, and by the time you tried to add enough bass treatment to mitigate, you’ll not have much of a listening area. I’d suggest smaller (3-4”) monopole full range driver system - no surprise there, I guess - less likely to excite lower frequency room modes, and a diagonal placement if at all feasible.
DECWARE - Article about Setting up a Listening Room without Treatments
 

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Today's progress. Spent about 3 hours cutting them up. A friend helped me to figure out the curve and the angle on the sides. I followed the cut list on the pdf and managed to make a diffuser with the off-cut. The plywood is of poor quality, it's warped and full of void. I'm leaving them clamped to the table until next week.

P.S. Even with this quality of a wood, it's still preferable to MDF or not?
 

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