[renaudrenaud]

Well, I finally understood what is wrong with this story. Really wrong.

[opnly bafld]

[

[renaudrenaud]

This is not a question of ability for a driver to work in open baffle or not.

 The question, for me, was the difference between the prices and the specs from taobao in a side, and the western website in the other side.

The explanation is here in this thread :

https://www.diyaudio.com/community/threads/new-lii-audio-fast-15-anyone-hear-these-yet.391776/

Main explanation on page 2. How an employee stole the name and cheat with the products on the western market.

[FullRangeMan]

Apparently both companies are solidly constituted technically.
In view of these unexpected probs I would not buy the F15 in
any way,  much  less  the FAST-15, but  only  the  F18  from
Lii Audio.com what have a good Qts and maybe dont need a sub
https://www.lii-audio.com/product/one-pair-18-inch-full-range-speakers-superb-scale-soundstage-with-new-imaging-f-18/
Technical Data:
Impedance: 8 ohm
Power: 40 – 80 W
Frequency response: Fu – 15k Hz
Fs: 38.7 Hz
Sd: 119.46 cm²
Qms: 18.656
Qes: 0.985
Qts: 0.935
Sensitivity: 97.8 dB （2.83V/1m）
Vas: 661.77 litres
Weight (a pair): 18 KG
http://www.glowinthedarkaudio.com/lii-audio-f18.html

[renaudrenaud]

Finally found how to upload an image.

[FullRangeMan]

Looks great, lets us know how it sounds after the break-in.

[renaudrenaud]

Ha... It is working since last Saturday and I am working at home, so it means it is from 08:00 to 23:00 each day.

I use a little amp, the FOSI BTA20 pro, paid 57€, so the total cost with the amp was less than 400€.

I am very happy with the results because it was a fun project shared with my wife. She helped a lot, in particular with the wood. She knows a lot in mechanic (and a lot of other topics, but mechanic knowledge is good for building a first Open Baffle). We continue to work on the project with a full toolbox of ideas.

Not sure to be qualified to describe the sound but I can try with my words and my own feeling
 - sound is very soft, not tiring, comfortable
- on vocals, male or female, it is verry good
- nice 3D presentation
- lot of micro details
- dynamic is spectacular 

I've ordered an Umik-1 and will take some measurements with REW and will see if we need some convolution.

I did not test BASTA! yet for simulation, it runs only on zindozs and I hate this OS, I do not like telemetry, adds and bloatware. I do not know how to manage that yet (a VM with WIndows 2000 maybe).

My wife designed the model, ordered the wood and cut it.













We plan to re-cut but I want some measurements before we cut the round shape. 

[FullRangeMan]

The driver in a low position near the floor will delivery more bass.

[kd4ylq]

Maybe more bass with the driver closer to the floor, but at the expense of imaging - not the right trade-off IMO. Keep the driver CL near your sitting ear height (I found that out the hard way).

[renaudrenaud]

Yes, we are designing a support for the panel allowing us a fine tuning for the angle.

[FullRangeMan]

Chances are you will dont like a too slanted angle.
This is your wife working for you in the wood working?
Incredible, you really are a locky man.

[Poultrygeist]

Tried the F15 solo in a wide baffle but much prefer it in a smaller baffle bi-amped with bass woofer support.

[Poultrygeist]

My first experimental baffle using the F-15 was sort of a cross between the dimensions of the Decware and Mr. Glow-in-the-dark's version. Bass was weak but probably ok for some. Elevating the F-15 atop the H-frame supporting woofers proved to be a much better solution.

[kd4ylq]

Chances are you will dont like a too slanted angle.
This is your wife working for you in the wood working?
Incredible, you really are a locky man.

I built my F15 stands with adjustable tilt angle. I use a digital angle gauge to measure and ensure they are both the same. The optimum tilt angle is different for different listening distances from the speaker (obviously?)

[FullRangeMan]

My first experimental baffle using the F-15 was sort of a cross between the dimensions of the Decware and Mr. Glow-in-the-dark's version. Bass was weak but probably ok for some. Elevating the F-15 atop the H-frame supporting woofers proved to be a much better solution.

Do you could stuffing inside the H Frame walls with 10mm car wood blanket to increase the bass and inform us the results?

[Poultrygeist]

I use 3/4" MDF covered with heavy wallpaper. Filler between layers or thicker baffles may be required to reduce resonance if one plays at extreme SPL's but I don't.

I favor MDF for baffles as it tends to be deader that plywood. The objective with OB's is you don't want to hear the baffles.

[Poultrygeist]

Cork also works well to combat baffle resonance. Here I used thick cork placemats from Ikea.