[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.

[jk@home]

To the OP, how is this driver working out for you? After reading the diyAudio thread you posted, got the impression that the Xizi morning glory  / non-Lii Song drivers (like you used) were not available in the US. Then found this on Amazon:

https://www.amazon.com/AVPLAY-FAST-15-Frequency-Speaker-50-80W/dp/B0C3GRFJTK/ref=sr_1_3?keywords=lii%2Baudio&qid=1703523181&sr=8-3&th=1

Like you posted, this driver claims to have a QTS of .99

Full disclosure, I'm interested in this driver instead of the Lii song model mainly due to the ability to buy it from Amazon (with my Store Card).

FYI, found their web site:

https://www.lii-audio-hifi.com/

[jk@home]

Finally got my new Fast 15s in a test baffle....I know this is all wrong, but just temporary  The plan is to do a PAP style modular OB. As of now, decided to have the Fii in the middle, and two Eminence Beta 15 bass drivers underneath and above.  Tried the Fiis on the floor, a little higher up on some milk crates (for WMW), and then on my 24" stands (for MWW). Very happy with what I'm hearing so far.

Right now driving them with a W4S M-pre/ dual M-amps, will use Crown XLS1500s for the bass driver, and IB subs in the ceiling above, if needed...

[ZAKski288]

Just came across these on FB,