18in Full Range Driver

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Ray P
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#1 18in Full Range Driver

Post by Ray P »

I'm aware that the 10in Lii Audio units aren't held in high regard here, but I thought this looked of sufficient interest to post;

http://glowinthedarkaudio.com/lii-audio-f18.html
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#2 Re: 18in Full Range Driver

Post by steve s »

That looks like a brave speaker design ray, but I would think some biggish compromises too.
I would love to hear them all the same
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#3 Re: 18in Full Range Driver

Post by IslandPink »

It would be interesting to see the spec, even if just as an OB bass. Are they on the Lii website ?
I will have to check.
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Ray P
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#4 Re: 18in Full Range Driver

Post by Ray P »

IslandPink wrote: Thu Apr 29, 2021 4:28 pm It would be interesting to see the spec...
https://www.lii-audio.com/product/one-p ... ging-f-18/
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#5 Re: 18in Full Range Driver

Post by JamesD »

Would not expect it to be very good as an OB with that Qts/Qes... underdamped enough so that the lf resonance swamps any sense of timbre from the beasties and a tendency to 'one note' style bass... I would be very surprised if they do make a cello sound real as claimed in the glow in the dark audio link and I've been trying to work out how those baffles work to give real lf extension and how the driver can sound fast with that Qts value??? Needs a good few Neo magnets added to the driver to help it out in the lf but that probably causes problems in the response higher in the frequency range...

All in all I'm puzzled by the account and somewhat sceptical...

A Faitel Pro 18FH500 crossed over to a Sonido SFR200 at 120Hz on a properly shaped baffle would cost less and blow the Lli out of the water...

Just my two pen'th...
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#6 Re: 18in Full Range Driver

Post by IslandPink »

I was disappointed when I saw the Qts.
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Ray P
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#7 Re: 18in Full Range Driver

Post by Ray P »

JamesD wrote: Thu Apr 29, 2021 9:33 pm A Faitel Pro 18FH500 crossed over to a Sonido SFR200 at 120Hz on a properly shaped baffle...
Presumably a Quasar?
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#8 Re: 18in Full Range Driver

Post by Scottmoose »

IslandPink wrote: Thu Apr 29, 2021 9:45 pm I was disappointed when I saw the Qts.
I suspect you'd be even more disappointed if they're anything like a pair of the 12in units (IIRC) somebody measured on DIYAudio, which are supposed to have a Qt with a voltage source of just over 0.7 and turned out to average around 2.0. ;)

I'd really like to support Lii Audio; the broad idea of large widebands is good, there aren't many on the market after all. But they don't always do themselves many favours (I accept that coming from me, that's a bit rich). OTOH, this is also possibly why, outright extension notwithstanding, so many seem to be happy with the LF performance with the drivers mounted on a very simple baffle, or even baffleless.
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#9 Re: 18in Full Range Driver

Post by JamesD »

Ray said
Presumably a Quasar?
Not necessarily :D

It needs a design that supports the bottom end response rather than use a limited size baffle with its natural roll off... Examples would be:

Pass SLOB style
Quasar style
Martin King style
J-C Morrison ETF style
Bert Doppenberg style OBs
Supravox Style OBs

etc. etc.

A few of these are based on the same principles for example my Quasar design starts from the Early Supravox designs and Berts initial OB design ( it uses his series crossover for the drivers too) and evolves from there...

The one common factor is support of the bottom end frequency response to take it beyond what simple baffle theory alone would support...

The dark audio site design linked above does none of that and then compounds the omission by adding large holes in the baffle side panels... I dread to think what they were added to hide/control - actually it might well of been the resonance peak introduced by the larger than 1 (in practice) Qts...
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