Lii Audio 21 Inch Woofer for Bass Compensation of Open Baffle or Cabinet | W-21

[JohnnyAudio]

Help me design a sub with this 21" speaker.

OB or box... looking for a fun, good looking sub not too obnoxious.

92 dB should be pleasant.

Lii Audio 21 Inch Woofer for Bass Compensation of Open Baffle or Cabinet | W-21

Technical Data:

1. Related power – Maximum power: 200W – 250W
2. Nominal Inpendance Z: 8+8 Ohm
3. Fs: 23.78Hz
4. Qms: 6.438
5. Vas: 913.57 L
6. Cms: 0.528 mm/N
7. Mms: 643.9 g
8. Sd: 2614.82 sqcm
9. Qes: 0.934
10. Qts: 0.816
11. Re: 7.60 ohm
12. Sensitiviry (2.83V / 1m): 92 .1dB （single coil）

Weight (unit in package) 30KG

 

[SIY]

Do you have an Xmax spec? The Qts and fs suggest a large open baffle, but Xmax needs to be decent for that to work.

 

[Ktacos]

I don't trust anything from this company, they have a 15" full range with very flat response (for what it is) from 40-20khz? with clean impedance all the way through and no break up? Yeah I don't buy it.

 

[NTK]

Are they wrong or Wikipedia is wrong? From the Wikipedia T/S parameters page:

Calculating fs and Vas, the results of both don't match the formulas. The number from OP were Fs = 23.78 Hz and Vas = 913.57 L = 0.91357 m^3.
???

 

[JohnnyAudio]

Do you have an Xmax spec? The Qts and fs suggest a large open baffle, but Xmax needs to be decent for that to work.

i will request the spec.

 

[JohnnyAudio]

I don't trust anything from this company, they have a 15" full range with very flat response (for what it is) from 40-20khz? with clean impedance all the way through and no break up? Yeah I don't buy it.

I have their P10s & S10s and love them both.

 

[Ktacos]

I have their P10s & S10s and love them both.

Congratulations, means nothing in regards to what I said though.

 

[DVDdoug]

Get some speaker design software, plug-in the parameters (if you trust them), and it will help you optimize the design and it will model the performance.

I've used WinISD which is free but it doesn't do open baffle designs.

 

[MAB]

Help me design a sub with this 21" speaker.

OB or box... looking for a fun, good looking sub not too obnoxious.

92 dB should be pleasant.

Lii Audio 21 Inch Woofer for Bass Compensation of Open Baffle or Cabinet | W-21

View attachment 404084

Technical Data:

1. Related power – Maximum power: 200W – 250W
2. Nominal Inpendance Z: 8+8 Ohm
3. Fs: 23.78Hz
4. Qms: 6.438
5. Vas: 913.57 L
6. Cms: 0.528 mm/N
7. Mms: 643.9 g
8. Sd: 2614.82 sqcm
9. Qes: 0.934
10. Qts: 0.816
11. Re: 7.60 ohm
12. Sensitiviry (2.83V / 1m): 92 .1dB （single coil）

Weight (unit in package) 30KG

You asked this before. I tried to give a balanced answer. It's very hard to take a driver manufacturer seriously who can't publish complete and physically consistent specifications. It takes a few seconds to actually measure. And it only takes a few seconds to confirm that provided measurements are bogus.

Do you have basic speaker measurement tools? Like a measurement microphone, and a DATS or some way of measuring small signal parameters... Have you tried any modeling software? You can quickly determine what a driver can do, if the provided data is correct, which in this case is not likely without measuring yourself.

I also note that Lii make some very expensive fullrangers, seem to be based on preceding questionable designs (i.e. very bad). This is a warning flag on a number of levels. Good sounding fullrangers are cheap, and the goodness they produce is quite limited.

I have their P10s & S10s and love them both.

Oh, I'm sorry. Perhaps if you measured them and post the data it might help.

 

[ppataki]

Help me design a sub with this 21" speaker.

OB or box... looking for a fun, good looking sub not too obnoxious.

92 dB should be pleasant.

Lii Audio 21 Inch Woofer for Bass Compensation of Open Baffle or Cabinet | W-21

View attachment 404084

Technical Data:

1. Related power – Maximum power: 200W – 250W
2. Nominal Inpendance Z: 8+8 Ohm
3. Fs: 23.78Hz
4. Qms: 6.438
5. Vas: 913.57 L
6. Cms: 0.528 mm/N
7. Mms: 643.9 g
8. Sd: 2614.82 sqcm
9. Qes: 0.934
10. Qts: 0.816
11. Re: 7.60 ohm
12. Sensitiviry (2.83V / 1m): 92 .1dB （single coil）

Weight (unit in package) 30KG

Those T/S parameters do not correspond to reality for sure
This is what happens if you want to simulate this driver in BassBox Pro:

The traffic lights shall all be green; red means that the values do not make sense

Just for a reference, this is the Lavoce NBASS08-20 driver; all green

 

[Ktacos]

Those T/S parameters do not correspond to reality for sure
This is what happens if you want to simulate this driver in BassBox Pro:

View attachment 404115

The traffic lights shall all be green; red means that the values do not make sense

Just for a reference, this is the Lavoce NBASS08-20 driver; all green

View attachment 404116

Wow that's a lot of incorrect values, usually in winisd I might get one. Makes me wonder how they even came up with the info.

 

[ChrisG]

Just a passing note that I had the misfortune of having to work with a pair of their Fast-10 full-range drivers. Don't use them above about 1kHz. They made Fostex and Lowther full-range units seem creamy smooth and easy-to-listen-to.

The published graphs might be flat, but those units were the most coloured/uneven/wretched thing I've measured.

Chris

 

[JohnnyAudio]

You guys are frightening me.
Thanks.

 

[DVDdoug]

If you already bought the speaker, or if you are intent on using it, as MAB suggests, you can get DATS for about $100 USD and measure it yourself. Otherwise, it's a shot in the dark.

Or, sealed boxes are less fussy than other designs and you are less-likely to end-up with a bad sounding design with a random driver in a random sealed box.

 

[mhardy6647]

If you already bought the speaker, or if you are intent on using it, as MAB suggests, you can get DATS for about $100 USD and measure it yourself. Otherwise, it's a shot in the dark.

... and a good investment it would be for pretty much anyone with any sort of serious interest in loudspeaker design and/or performance.
One may also measure T/S parameters by hand with relatively simple tools, but for a hundred bucks (in the US), yeah... go for the gusto!

Measuring Loudspeaker Driver Parameters

sound-au.com

I have zero ears-on experience with any of the Lii drivers. They're attractive but 1) there are so many variants and 2) if it (in this case, it is the mfgr's reported specifications) seems too good to be true -- it probably is.

Doesn't Foster (Fostex) still make and sell a big woofer?
Looks like it...

Fostex FW800HS, 31.5" Super Woofer

31.5" Super-Woofer! Features ♦800mm (31.5") cone ♦8 ohm impedance ♦fo to 1.5kHz frequency response ♦96dB sensitivity at 1W/1m (3.3ft)

www.madisoundspeakerstore.com

PartsExpress in the US has a couple of large "subwoofer" drivers.

Nominal Diameter

Need the perfect woofer? The fantastic selection at Parts Express includes all of the best loudspeaker brands, with a full variety of sizes and materials.

www.parts-express.com

and some large-format pro woofers

Nominal Diameter

Discover peak audio reproduction quality with pro woofers, subs, and midrange drivers. Go for the best in live sound speakers from trusted industry brands.

www.parts-express.com

 

[ChrisG]

Found some old measurements from the Fast 10. IIRC, it was one of their earlier efforts, perhaps newer ones are better etc etc etc.

Chris

 

[mhardy6647]

Found some old measurements from the Fast 10. IIRC, it was one of their earlier efforts, perhaps newer ones are better etc etc etc.

View attachment 404254

Chris

That'll certainly sound fast and detailed.
Oy.

 

[ChrisG]

It was borderline-passable playing that HiFi show favourite: Keith Don't Go (Live) by Nihls Lofgren. I believe that recording is so strongly favoured because even a mediocre system can sound quite reasonable when playing it.

I tried playing some Reggae, and every weakness was laid bare immediately.



FWIW, there are plenty of very good 21" woofers around. I'd stick with a reputable manufacturer unless the Lii price is "cheap enough that I don't care".


Chris

 

[mhardy6647]

FWIW, there are plenty of very good 21" woofers around. I'd stick with a reputable manufacturer unless the Lii price is "cheap enough that I don't care".

Which I reckon is bloody unlikely! The Lii drivers have become quite expensive.

PS yes, FWIW, I concur, myriad other, almost certainly better choices -- more cost-effective choices, at that.

 

[ppataki]

It was borderline-passable playing that HiFi show favourite: Keith Don't Go (Live) by Nihls Lofgren. I believe that recording is so strongly favoured because even a mediocre system can sound quite reasonable when playing it.

I tried playing some Reggae, and every weakness was laid bare immediately.



FWIW, there are plenty of very good 21" woofers around. I'd stick with a reputable manufacturer unless the Lii price is "cheap enough that I don't care".


Chris

Not sure where you are located Chris, but in Europe I would very strongly recommend the Lavoce brand; I have had extremely good experience with their sub drivers so far
I have built several projects using their 8" and 15" drivers - top price/value ratio in my opinion (you can find all of them here documented with measurements on ASR)