Hi!
I have a pair of Lii Silver 8's that I'd love to use in a bookshelf enclosure, something compact ... I've been experimenting all week, and out of my 6 or so prototypes, they all have one thing in common - A MASSIVE nose dive at 110hz .. is there anyway to get to at least 70 without a massive transmission line box? Thanks!
I have a pair of Lii Silver 8's that I'd love to use in a bookshelf enclosure, something compact ... I've been experimenting all week, and out of my 6 or so prototypes, they all have one thing in common - A MASSIVE nose dive at 110hz .. is there anyway to get to at least 70 without a massive transmission line box? Thanks!
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thats a super horn driver, a waste of money in a small enclosure, in my Sousaphon the Rms is lower than others, i like the driver a bit smoother than the tested DX2.
OK, an interesting one, since looking at the posted LMS data on the Silver 6 page, it doesn't match up. If Fs, Re, Q and Vas are correct, neither B*L nor Mms can be what is published, and visa versa. These values are inherently connected, so there's no option for them to vary. Either there is an error in the published data, or Lii Audio are using an average from a batch of measurements for each value. If that were the case though, you wouldn't expect Qt to line up perfectly with the stated Qe and Qm, but it does. Curiouser and curiouser.
Based on that, I would be wary of designing anything using the published figures. However, as an observation: it's usually quite easy for manufacturers to get Mms consistent. Assuming Fs, Q and Re are all reasonably correct, and adjusting Vas (harder to measure accurately) so the rest line up, it really needs a bigger box than 8.5 litres, and something like that volume, tuned to, say, 65Hz, would have an anechoic F3 of about 95Hz. I don't normally use F3 as a metric, but it's just an example that the system response is going to drop away at a relatively high frequency.
Based on that, I would be wary of designing anything using the published figures. However, as an observation: it's usually quite easy for manufacturers to get Mms consistent. Assuming Fs, Q and Re are all reasonably correct, and adjusting Vas (harder to measure accurately) so the rest line up, it really needs a bigger box than 8.5 litres, and something like that volume, tuned to, say, 65Hz, would have an anechoic F3 of about 95Hz. I don't normally use F3 as a metric, but it's just an example that the system response is going to drop away at a relatively high frequency.
Thanks for the response! So I'm basically trying to do the impossible?
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This driver needs a massive box and a high Rout amp or a high ohm loading to work in reflex. When i sim, i only get good result if i put a restance of 3ohm on front, then a 90L ported cabinet can get to below 40 on low power. And for an MLTL it's also not that suited with that low qts and xmax. This driver was ment for backloaded horns i think (who are also big) and tube amplifiers, that is what the public for this kind of drivers mostly want.
If you do that in reality the restor need to be able to handle the full power of the driver, so i nrealy to put 4 or more in parallel so the end result is 3ohm.
If you do that in reality the restor need to be able to handle the full power of the driver, so i nrealy to put 4 or more in parallel so the end result is 3ohm.
HOPING maybe this will work
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The smallest ported box that I see, which will yield a fairly smooth bass response is 22 liters, with a port tuned to 50~52.5 Hz. That tuning could be accomplished with a 3" diameter x 6.63"~7.5" long port. The F10 will be 41.6~42.6 Hz.
Most of the specs I used are on the top of this page
https://www.lii-audio.com/product/one-pair-new-8-fullrange-drivers-premium-level-sound-silver-8/
Other parameters are on the Notes section at the bottom of the SPL/Z plot.
The 8.5 L / 70 Hz vented has a slight (2-3dB) hump in SPL between 125-250Hz, which may or may not be desirable.
The 22 L box / 50Hz doesn't show a hump above the tuning freq.
I usually try to avoid any hump in the raw box sizing, but 2 or 3 dB may not be a problem.
The 22 L box / 50Hz doesn't show a hump above the tuning freq.
I usually try to avoid any hump in the raw box sizing, but 2 or 3 dB may not be a problem.
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OK, I just used the requested 8.5 L as an example WRT max available system efficiency.
