I had a bit of luck modifying the LXMini speakers by integrating some AMT tweeters (Dayton AMT Mini-8) with a steep 8th order LR crossover at 6Khz in the MiniDSP.
The off-axis response is a definite improvement over running just the seas midrange with out a LPF and they sound good too.
I had a go at 3D printing the brackets and am happy with the way it all turned out.
The off-axis response is a definite improvement over running just the seas midrange with out a LPF and they sound good too.
I had a go at 3D printing the brackets and am happy with the way it all turned out.
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so in essence are you running the amt as a super tweeter? Dayton claims a response out to 40KHz but I don't see that in your graph
Nicely done!
I'd always thought the original Pluto sounded better (overall, though not quite as clear).
My guess is that this would combine the best aspects of both.
I'd always thought the original Pluto sounded better (overall, though not quite as clear).
My guess is that this would combine the best aspects of both.
have heard the lx mini at burning amp many times and the ONLY thing I could critique would be a slight thickening in the lower registers. I could be wrong but I surmised that was either from the long excursion 10 subs, or just pushing them to play loud in a big room. Alas the room I will play them in is much smaller. Having said that I have heard set ups at audio demo's where a super tweeter seemed to magically clarify the entire spectrum. In any case I have parts and slowly but surely am getting my Lx Mini's put together with the Pass crossover.
rich31td, Do they sound bright? The graph looks like they might. I'd lower the amt output by 3db and take a closer look at the LR8 each driver separately. I'm sort of curious what the off-axis null around your Fx is all about.
See what you think with these two old measurements I made of two drivers separately.
Midrange is running without LPF and AMT with 4Khz HPF iirc.
Maybe dropping the HPF down to ~5.5Khz might help?
Midrange is running without LPF and AMT with 4Khz HPF iirc.
Maybe dropping the HPF down to ~5.5Khz might help?
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I'd be inclined to try 7 kHz and a filter result that better "blends" the two drivers off-axis at lower freq.s.
Perhaps -3db for the tweeter at 7 kHz as a "starting point".
Perhaps -3db for the tweeter at 7 kHz as a "starting point".
That explains all the energy above 6khz. So no LP on the mid ...why again?
Do you try with one and not like it? That null around 5.3khz should be corrected too if you can.
Try it with a lp on the mid, correct the tweeter response a bit and see where you're at.
Do you try with one and not like it? That null around 5.3khz should be corrected too if you can.
Try it with a lp on the mid, correct the tweeter response a bit and see where you're at.
my beef with LXMinis has always been: too bright i.e. missing the low mid/upper bass which makes the speakers sound "big". LX521 has an 8 inch driver and still a significant boost around 500Hz in EQ. It was also noted by others that LXMinis sound better when played loud. I have both.
Another LXMini/LX521-like speaker may be in the cards for me down the road, even with different drivers which proved themselves in my home-brewed OB. It is a big project though and the conditions are not right yet for me to go all out and do it just for the fun of it (if retired it would have been perfect but not yet..🙂. I am pretty sure some improvement is still possible based on Siegfried's design principles.
Another LXMini/LX521-like speaker may be in the cards for me down the road, even with different drivers which proved themselves in my home-brewed OB. It is a big project though and the conditions are not right yet for me to go all out and do it just for the fun of it (if retired it would have been perfect but not yet..🙂. I am pretty sure some improvement is still possible based on Siegfried's design principles.
The first measurement is of both drivers with a x-over at 6Khz, so LP on the midrange and HP on the AMT, the measurement of just the midrange is that of the LXMini design more for comparison which never had a LP.
rich31td .. So, the graph in post #1 represents both the mid and the amt with an LR8 xo @6khz .. is that right?
The graphs in post #8 represent older measurements of the mid only (graph on the left), no LPF ... is that right? If so, irrelevant to this discussion.
The graph on the right represents the amt only with the HPF of LR8 set @6khz. Is that correct?
Can you measure the drivers individually as you had them set-up in post #1 with each drivers (6khz) xo filter in place? Don't move the mic and keep the spl(s) the same for each.
The graphs in post #8 represent older measurements of the mid only (graph on the left), no LPF ... is that right? If so, irrelevant to this discussion.
The graph on the right represents the amt only with the HPF of LR8 set @6khz. Is that correct?
Can you measure the drivers individually as you had them set-up in post #1 with each drivers (6khz) xo filter in place? Don't move the mic and keep the spl(s) the same for each.
Nice work rich31td!
8th xo at 6kHz practically eliminates vertical lobing at xo. But did your try, measure and listen to other xo types and points? Was 8th best by measurements or by listening?
Others, please remember that LXmini has monopole bass crossed to dipole midtweeter, but LX521 is dipole all the way. Naturally they use different eq, and with dsp the user should have courage to adjust room response to the room and personal taste! Easy with minidsp.
8th xo at 6kHz practically eliminates vertical lobing at xo. But did your try, measure and listen to other xo types and points? Was 8th best by measurements or by listening?
Others, please remember that LXmini has monopole bass crossed to dipole midtweeter, but LX521 is dipole all the way. Naturally they use different eq, and with dsp the user should have courage to adjust room response to the room and personal taste! Easy with minidsp.
AMT tweeter in lieu of full range driver?
I’m considering replacing the full range drivers on my home brewed LXmini type speaker with the Dayton Audio ES104AMT-4 AMT(dipole) tweeter currently for sale at PE.
The woofers are 15W8530k01 crossed at 2500Hz to TBand W3-1364sa.
I’m not dissatisfied with the performance as is, but in the interests of Diy, I am thinking the AMT may add some sparkle.
Any thoughts?
Stay safe.
Peter
I’m considering replacing the full range drivers on my home brewed LXmini type speaker with the Dayton Audio ES104AMT-4 AMT(dipole) tweeter currently for sale at PE.
The woofers are 15W8530k01 crossed at 2500Hz to TBand W3-1364sa.
I’m not dissatisfied with the performance as is, but in the interests of Diy, I am thinking the AMT may add some sparkle.
Any thoughts?
Stay safe.
Peter
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Should be good at 2.5k.
AMTs being displacement limited, it's best to be conservative for full volume use.
On a desktop that tweeter can go quite low, but there you aren't asking for high spl.
Let us know how you like those particularAMTs.(before they're all gone)
Best, David
AMTs being displacement limited, it's best to be conservative for full volume use.
On a desktop that tweeter can go quite low, but there you aren't asking for high spl.
Let us know how you like those particularAMTs.(before they're all gone)
Best, David
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Joined 2006
What about changing the Aura Whisper (1.5" cone) to Aura Cougar (3/4"), that would bring it more omni, wondered if anyone tried..😀
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Joined 2006
Crossing at 2.5khz is way too high, woofer will have problems on the vertical dipersion. See the response curves at 1 khz and 2.5khz of your woofer. Try lowering it, and you should hear improvements.
There are good reasons to have it down at 1khz or below in the original designs. 🙂
The dispersion is rather different mounted at the end of a tube from mounted on a flat, large baffle.
And it seems to be working for Peter.
Just don't stand over the speaker looking down(which provides other problems with more conventional layouts).
And it seems to be working for Peter.
Just don't stand over the speaker looking down(which provides other problems with more conventional layouts).
3" cone as dipole can't handle lower midrange because of distortion getting high. 6-6½" woofer starts beaming at 2kHz and tube "baffle" doesn't change that - it affects only at lower freqs.
Reasonable xo might be around 800-1200Hz -depends on how loud you want to listen. With LR2 xo cardioid dispersion pattern will be about one octave around xo. Steeper xo makes transition omni-cardioid-dipole sharper which may lead to audible problems with tonality.
3" cone loses smooth response and dispersion gets narrower typically around 6-8kHz, so a tweeter is a good idea, if one has dsp/amp channels available. Up there dipole radiation is not critical, room decay will show the difference but it is difficult to hear without immediate comparison.
Reasonable xo might be around 800-1200Hz -depends on how loud you want to listen. With LR2 xo cardioid dispersion pattern will be about one octave around xo. Steeper xo makes transition omni-cardioid-dipole sharper which may lead to audible problems with tonality.
3" cone loses smooth response and dispersion gets narrower typically around 6-8kHz, so a tweeter is a good idea, if one has dsp/amp channels available. Up there dipole radiation is not critical, room decay will show the difference but it is difficult to hear without immediate comparison.
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