l have looked at your earlier pics and l think the 300 hertz dip is floor bounce from 1/2 wavelength looking at the baffle
Try putting the mic on the floor and do a ground plane measurements at 1 metre. Tilt the enclosure a bit so you get the horn in its vertical polar response.
Try putting the mic on the floor and do a ground plane measurements at 1 metre. Tilt the enclosure a bit so you get the horn in its vertical polar response.
Ok I will try that, will need help to hold the monster thought 😀
I played a bit with a better calculator I’ve just found (http://tripp.com.au/sbir.htm).
Here on a manually normalized comparison near field/far field.
So it says 500/hz1500Hz for the nulls and 1000/2000hz for the peaks, I think we can see them, even if very soft above 500Hz.
Same for the ceiling effect, 88/170/260hz are visible.
Maybe above that it’s all a combination of these effects.
I played a bit with a better calculator I’ve just found (http://tripp.com.au/sbir.htm).
Here on a manually normalized comparison near field/far field.
So it says 500/hz1500Hz for the nulls and 1000/2000hz for the peaks, I think we can see them, even if very soft above 500Hz.
Same for the ceiling effect, 88/170/260hz are visible.
Maybe above that it’s all a combination of these effects.
Building slowly the plan for outdoor measurements, where I will probably focus on mid/high only as a starting point, it will make everything simpler in term of height etc.
In the mean time I was trying to integrate my sub, had a lot of trouble with phases, left and right woofer were 90 degree out of phase between 40-60hz. Then I realised I never took a sweep with both L&R, didn't bother to test since I never had issue in the past.
But I moved them, so of course it could be different, so I tested it, and of course: big dip at 50Hz, almost one octave gone!
And I thought the box had trouble at 30Hz silly me... that’s what triggered the new sub by the way, among other reasons.
So I had to learn about all pass.
Also I tried last week a tune with LR8 on mid-horn, first time ever trying 48db slope.
So I could compare my old 1400Hz@24db, the previous 1400@12db and this last 1200@48db.
It was strange, not bad at all but something was bothering me with lr8, like it was almost too clean, too sharp.
Sound stages were very similar on all, but the 12db felt fuller.
So I took the time to retune everything, trying to find out how all pass filters work.
This time with MMM and rta, sweeps to be used for alignment and study modes later, and then the all pass.
Here we go:
Check off axis response of the mid-horn, just roughly few off axis degree at 1m, new preset no house target, no eq just XO
With 48db, very abrupt !
And the 10'' mid doesn't beam!
With 12db, looks much better:
Then I tried 1400,1600,1800 and 2khz with more granularity, it appeared quickly that 1600/1800 were apparently the sweet spot in term of smoothness between mid and horn off axis response.
Not very visible here I took so many I couldn't keep track, but it gives the idea:
So I decide to tune with 1800Hz, 2nd order then.
Just xo, rta at mlp:
Then a bit of EQ, low Q on mids, and very light on horns Q1:
Then I took sweeps at MLP to check and for the phases (level off):
Then time alignment, reverse polarity method.
I tried the REW alignment but it was always off (I suppose it's due to the lack of precise timing reference with my usb mic?)
+1 on mids and check summing:
Haha, the big dip!
Highs are off, probably mic not perfectly centered I didn't care.
With RTA:
Ok now let's try all pass, did some test before and it kind of worked but I really was working blind.
So Left & Right woofers phases:
Then playing with EQ, all pass at 50Hz Q2:
The result:
\o/
It could probably be fine-tuned but I'm happy it worked.
I was concerned about fixing the phase at 50Hz but maybe creating some mess at 200Hz in the same time.
But no it worked fine.
The end result sounds great, for the bass it is so obvious.
To the point that I wonder if I need the sub… just built 😛
Yeah really good I'm happy, the 4 woofers are punching! 👊
In the mean time I was trying to integrate my sub, had a lot of trouble with phases, left and right woofer were 90 degree out of phase between 40-60hz. Then I realised I never took a sweep with both L&R, didn't bother to test since I never had issue in the past.
But I moved them, so of course it could be different, so I tested it, and of course: big dip at 50Hz, almost one octave gone!
And I thought the box had trouble at 30Hz silly me... that’s what triggered the new sub by the way, among other reasons.
So I had to learn about all pass.
Also I tried last week a tune with LR8 on mid-horn, first time ever trying 48db slope.
So I could compare my old 1400Hz@24db, the previous 1400@12db and this last 1200@48db.
It was strange, not bad at all but something was bothering me with lr8, like it was almost too clean, too sharp.
Sound stages were very similar on all, but the 12db felt fuller.
So I took the time to retune everything, trying to find out how all pass filters work.
This time with MMM and rta, sweeps to be used for alignment and study modes later, and then the all pass.
Here we go:
Check off axis response of the mid-horn, just roughly few off axis degree at 1m, new preset no house target, no eq just XO
With 48db, very abrupt !
And the 10'' mid doesn't beam!
With 12db, looks much better:
Then I tried 1400,1600,1800 and 2khz with more granularity, it appeared quickly that 1600/1800 were apparently the sweet spot in term of smoothness between mid and horn off axis response.
Not very visible here I took so many I couldn't keep track, but it gives the idea:
So I decide to tune with 1800Hz, 2nd order then.
Just xo, rta at mlp:
Then a bit of EQ, low Q on mids, and very light on horns Q1:
Then I took sweeps at MLP to check and for the phases (level off):
Then time alignment, reverse polarity method.
I tried the REW alignment but it was always off (I suppose it's due to the lack of precise timing reference with my usb mic?)
+1 on mids and check summing:
Haha, the big dip!
Highs are off, probably mic not perfectly centered I didn't care.
With RTA:
Ok now let's try all pass, did some test before and it kind of worked but I really was working blind.
So Left & Right woofers phases:
Then playing with EQ, all pass at 50Hz Q2:
The result:
\o/
It could probably be fine-tuned but I'm happy it worked.
I was concerned about fixing the phase at 50Hz but maybe creating some mess at 200Hz in the same time.
But no it worked fine.
The end result sounds great, for the bass it is so obvious.
To the point that I wonder if I need the sub… just built 😛
Yeah really good I'm happy, the 4 woofers are punching! 👊