[Bumpy]

The Q of the system is changed by the electronic EQ, aka bass boost. Any typical box driver with lower Q can be EQd in dipole to the desired target .6-.7 system Q.  But you can't EQ a driver with higher Q like Eminence Alpha down to lower target Q, because the driver cannot obey the amp. That's the problem stated in OP. 

I like the lowish Q of the FaitalPro. That means well damped and easily controlled by the amplifier and easily sculpted to the desired FR.
With 15" you only need a couple mm excursion, even in boosted LF. Xmax not a problem.

Thank you richido, you talk a lot of sense , which is nicely set against most of the hype on the forums. Just to confirm what you say about the x max. I have tried several 15" drivers in my OBs and at my typical listening levels in over 3 years have never seen them move, not even 1mm.

[Bumpy]

  but  Electric Efficiency=2.71% are a mid range value, not hi, but could be interesting to know how it perform in an OB panel.

Hi FRM

You mention specifically the value of Electric Efficiency. Can you explain the importance of this and why very few speaker manufacturers bother to include it in their TS parameters.

[FullRangeMan]

Hi FRM

You mention specifically the value of Electric Efficiency. Can you explain the importance of this and why very few speaker manufacturers bother to include it in their TS parameters.

TS name is η0  sometimes named Eta Zero
Measured in percentage %

It show how much per cent of the amp power applied to the driver is converted into sound. The bigger the better, the max I have seen was 5%.

and why very few speaker manufacturers bother to include it in their TS parameters.
Certainly they want hide his expensive speaker are inefficient.
Other value they hide are the recommended volume box range, range mean say a min and a max value.

[Bumpy]

TS name is η0  sometimes named Eta Zero
Measured in percentage %

It show how much per cent of the amp power applied to the driver is converted into sound. The bigger the better, the max I have seen was 5%.

Thanks. I guess this is not unlike efficiency.

[FullRangeMan]

FullRangeMan,

You seem to heartily endorse the Lii F15, F18 and the W15. Have you ever heard any of these drivers?

I ask because I have heard the F15’s and was less than impressed. I am still interested in the W15, it looks like it holds some promise. But I would be interested to hear the opinion of someone with direct experience with the driver.

I have not heard these drivers and canot guarantee they are extraordinary to everyone taste, but on the Glow inThe Dark, Decware and DIY Forums they are praised, personally I found the F15 freq chart to be excellent, too perfect even, if the sound is like the graph it is good, I have never see a so flat freq resp graphic.

[Woodsage]

They do seem to give away a lot of drivers. Two of my friends ended up getting free drivers, one got a Fast 8 and the other a six inch driver.

I ended up with the Fast 8. What it did it did pretty well but it didn’t go very low in an OB. What surprised me was how fast it rolled off at the top end.

I found the F15 to be a fuller sound but it also seemed rolled off at the top end. What surprised me was the midrange didn’t seem to be as full and impactful as other large format drivers I have heard.

To be fair I didn’t hear the F15 in my system so a lot of what I was hearing could have been room and system dependent.

There is a guy on YouTube using a Fast 8 in parallel with a F18 and added a omni directional tweeter. Looks like he’s having fun. Although with the Fast 8 I think I would have gone with a W15.

https://m.youtube.com/watch?v=oWJWVOZ0sbE

[Bumpy]

They do seem to give away a lot of drivers. Two of my friends ended up getting free drivers, one got a Fast 8 and the other a six inch driver.

Thanks for that insight God knows what their business plan is - it seems to flood the market with freebies, make friends and flood the internet with their reviews.

In reality their drivers are probably pretty good on the whole, with one or two sweet models like the W-15. But at the price of the better models they are up against some real competition and nobody is doing that comparison.

[FullRangeMan]

But at the price of the better models they are up against some real competition and nobody is doing that comparison.

You need read the Glow in The Dark site, this non commercial, no advertisement site have tested all the best FR drivers and his current top are the F-18.
http://www.glowinthedarkaudio.com/speakers.html
I was told Li Audio paper cones use the same paper as the expensives AER and Vox Active that of course is a made in China paper.

[Bumpy]

You need read the Glow in The Dark site, this non commercial, no advertisement site have tested all the best FR drivers and his current top are the F-18.
http://www.glowinthedarkaudio.com/speakers.html

I know that site, he says quite clearly on his home page "this is not a review site". I would second that, as almost every driver he tries is described in some way as great, there is little attempt to compare.

The W-18 seems to be just the latest driver he falls in love with, but if he put every other driver in that whacking great open baffle they would all step up gear.

[FullRangeMan]

He use the F-18 full range, not the W-18.
I have read all his articles, I have been following the site since it had few rewiers and he usually say when the speaker or amp are less great, it was very useful to me as a guidance, so I thought it would be useful to you too.

[Bumpy]

He use the F-18 full range, not the W-18.
I have read all his articles, I have been following the site since it had few rewiers and he usually say when the speaker or amp are less great, it was very useful to me as a guidance, so I thought it would be useful to you too.

Apologies, it was indeed the F-18, but my comments still apply. All over the forums are comments like "best I have ever heard", "beats everything up to £10,000". They're all irrelevant without context. I have lost count of how many bits of kit have disappointed after such glowing opinions.

[FullRangeMan]

From my assessment of the specifications of the F15 and F18 they are the best I have seen so far and cost little, being its freq chart true, but I must say I dont like small FR cones.

Lowthers neither are full ranges they could be classified as midranges and cost a fortune because they are made in UK.

[FullRangeMan]

Have located this comparative maybe it help you.

[Woodsage]

Reviews, Fan Boys, TS parameters, and graphs can all be helpful as guides. I’ve found they all need to be taken with a HUGE grain of salt. Especially when couched with “for the money.”

The only way to know if a driver works for you is to try it. I’ve tried a lot over the years so have a pretty good idea of what I like and what works for my application and budget.

I have found with full range drivers you pretty much get what you pay for. My AER drivers were the best I have owned and also the most expensive. And I’ve tried a lot of full range drivers, mostly 8”.

The Lii Fast 8 did look similar to my AER’s but I don’t think it was the exact paper. But I could be wrong.

Anyway, I haven’t written off the Lii large format drivers and would try some if I got them at a good price.

Carry on!

[FullRangeMan]

Glow in The Dark use a plain Alpha15A as OB woofer:
http://www.glowinthedarkaudio.com/audionirvana.html
A reliable way to evaluate woofers is analyze the TS Pars that always tell much more than a brief hearing in a noisy showroom.

There are certain parameters that must be taken into account with woofers:
Bass Reflex box = more bass
Bigger box = more bass
Huge power handling = hard to drive
OB need large excursion cones
Poor internal box treatment = little bass

[Woodsage]

I would add a reasonably high Qts and multiple woofers (preferably active) for OB.

The above does not necessarily apply to the OP.

[Bumpy]

I have yet to see any evidence that a flat frequency graph in a drivers specs is paramount in selecting a driver for OB.

It goes without saying that, in any given set of drivers, (ie loudspeaker), getting a better flat response will generally get you better sound quality. That's mostly about getting similar sensitivities and optimising crossovers.

BUT that does not mean that a driver itself with flat response will sound better than one without. This harks back to the early battles to evolve solid state amps with optimum specs. When those amp specs were perfected, surprisingly they did not sound the best.