Would this work ?
Sorry for such newbie questions .
Three layers front baffle where the front 15" is set on first board and full range on back of the opposite one ?
it'll work , but I can't imagine difference between voice coils depths being 6x baffle thickness
that's ( I presume) being 6 x 18mm
Would this work ?
Sorry for such newbie questions .
Three layers front baffle where the front 15" is set on first board and full range on back of the opposite one ?
Will you also run string lines from both drivers to your ears at your seating position and not move your head?
In the grand scheme of things, what is the difference in phase angle of an 80Hz wave at plus or minus 50mm.
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It is my belief the reason for the sloped baffle of Papa's original MINI SLOB design (with single woofer) is mostly to correct for the rising response seen in many FR drivers. When you sit slightly off axis of a FR driver you can correct for the rising response without the need for EQ circuitry.
Regarding the slot loaded woofer. Because air is somewhat elastic, the changing pressure at the front of the slot follows the movement of the speaker cone virtually instantly. In other words there is virtually no lag between the centre on the woofer cone and the front of the slot.
So my brain says (remembering I have a dumb brain though) the sloped baffle has very little to do with time alignment, and more to do with EQ correction of the FR driver.
In addition also consider the wavelength of an 80Hz sine wave.
If the operation of the slot loaded woofer (explained above) is mostly correct, then the slope of the baffle (in the original single woofer design) would possibly need to go in the opposite direction to get perfect time alignment. So I don't think time alignment is the reason, but more so Eq adjustment of the FR driver.
Regarding the slot loaded woofer. Because air is somewhat elastic, the changing pressure at the front of the slot follows the movement of the speaker cone virtually instantly. In other words there is virtually no lag between the centre on the woofer cone and the front of the slot.
So my brain says (remembering I have a dumb brain though) the sloped baffle has very little to do with time alignment, and more to do with EQ correction of the FR driver.
In addition also consider the wavelength of an 80Hz sine wave.
If the operation of the slot loaded woofer (explained above) is mostly correct, then the slope of the baffle (in the original single woofer design) would possibly need to go in the opposite direction to get perfect time alignment. So I don't think time alignment is the reason, but more so Eq adjustment of the FR driver.
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Another possibility, is that the slope is purely due to the fact that Papa wanted a slot with a cross sectional area that increases in size towards the opening (as seen in the diagram) and to make construction easier he used that sloping surface of the slot to mount the baffle on, and then he said "gee I'm a bloody smart bastard, I just killed 2 birds with one stone". hahaha
Possibly even more than 2 birds with one stone depending on the reasons.
Possibly even more than 2 birds with one stone depending on the reasons.
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There is a gap of circa 60mm ,
so 3x18mm (board thickness)=54
So very close, 0,6mm=0,023"
But i must do my math again and check.
Very instructive...
Let's starts with bot driver mounted on main baffle and let's improve later , this is DIY ;-)
Some more feedback from day#2: I toyed a lot yesterday with B5, struggling to find the right combo.
First of all, slotted bass is really great, giving very low bass output (see measurement in attachment, made with UMIK+REW).
But there is something missing, the impact of bass, so I guess the front will give me that.
thanks guys to pushing me further ;-)
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