@Wolf said:
Since you are perusing the Beyma notes; You'll also notice then that the 2 different tweeter builds have different bass Fb tunings according to the system impedance plots. This does not match the FR of the woofer in the 2 different systems, as one should be peaking and one should be flatter, yet, they are the same as shown with the same baffle, xover and woofer. That doesn't add up. It could also be a nearfield bass curve too (JR beat me to it).
My thoughts are that the 47Hz tuning is flatter than shown, and that both system FR show the woofer tuned to 52-55Hz or so. It just so happens my VersaBox is tuned to 47Hz, and most any 6.5" woofer thus far has performed splendidly well in there. I'll find out my preferences.
What's even more disturbing is that in Beyma's notes, the crossover suggested for the 6NMF is exactly the same as for the 8NMF.
I've been curious how one handles shapes like this without cnc. I've been loving using 3d printed templates - I've been bitten a few times now with my milescraft jig on porter cable router, think related to using a drywall screw for center vs provided screw, end up like 2mm wider than reading set to (sorry, tangent mention).
Still curious to see the creative solution to making the rebate since know not resort to a reddit posting of flange surface mounted with claims of diffraction only matters on tweet - bah, aesthetics is important too.
I’m probably not the best example for this, but in the past I’ve set up long extensions to my router to do swings in line with each side face of these drivers (as opposed to cutting out a big template for the router- which is probably the preferred way, but w/o wasting a board).
I just now saw the additional and separate NMF8W Recinto technote. Yeah, disturbing indeed. The one I attached has both tweeters with the 6.
My thought, sans template, is a combo of the right circle size jig, and a corner jig. Set the guide bearing half and half, so to speak. Half above for corners, and below in the circle areas.
This means use the circle jig first. The ears will come after with a pilot top bearing running against the corner jig.
I rarely do it, but I've gotten ok results freehanding. I guess I'd rather sweat bullets than deal with all the work of making jigs and all that. Normally I just say screw it and surface mount it if it isn't round
Before flexing by hand, I ran a set of T/S out of the box:
And afterwards...
I must say I'm rather pleased at how close these ^ numbers are.
However, after closer inspection, the dustcap on one unit is shifted off center about 3/16". It seems some manufacturers have issues with getting this perfectly centered, depending totally on the assembly methods. That said, unless you look right at the dustcap, it is hard to see it. As long as the lateral shift isn't visible, mounting orientation can fix most of its visibility. Still, I would think a $275 woofer should have this issue licked.
Yeah that is disheartening. I think I have mounted ones with offset dustcaps so the droop is at the downward spot. Because of the normal viewing angles (IE looking down at the woofer) It can make it tough to spot, even if you know it is there.
It appears that these can take up to 78W/103dB before mechanical issues occur. The port is just touching that border before turbulence ensues, and the voice coil has not yet hit Xmech.
However, under a more normal 40W/100dB peaking, the Xmax (+15%) is good down to 23Hz before breaching xmax. That is just phenomenal capability for a slightly larger than average 6.5" woofer.
Comments
What's even more disturbing is that in Beyma's notes, the crossover suggested for the 6NMF is exactly the same as for the 8NMF.
I've been curious how one handles shapes like this without cnc. I've been loving using 3d printed templates - I've been bitten a few times now with my milescraft jig on porter cable router, think related to using a drywall screw for center vs provided screw, end up like 2mm wider than reading set to (sorry, tangent mention).
Still curious to see the creative solution to making the rebate since know not resort to a reddit posting of flange surface mounted with claims of diffraction only matters on tweet - bah, aesthetics is important too.
I’m probably not the best example for this, but in the past I’ve set up long extensions to my router to do swings in line with each side face of these drivers (as opposed to cutting out a big template for the router- which is probably the preferred way, but w/o wasting a board).
I just now saw the additional and separate NMF8W Recinto technote. Yeah, disturbing indeed. The one I attached has both tweeters with the 6.
My thought, sans template, is a combo of the right circle size jig, and a corner jig. Set the guide bearing half and half, so to speak. Half above for corners, and below in the circle areas.
This means use the circle jig first. The ears will come after with a pilot top bearing running against the corner jig.
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I rarely do it, but I've gotten ok results freehanding. I guess I'd rather sweat bullets than deal with all the work of making jigs and all that. Normally I just say screw it and surface mount it if it isn't round
Okay, some data...
Before flexing by hand, I ran a set of T/S out of the box:
And afterwards...
I must say I'm rather pleased at how close these ^ numbers are.
However, after closer inspection, the dustcap on one unit is shifted off center about 3/16". It seems some manufacturers have issues with getting this perfectly centered, depending totally on the assembly methods. That said, unless you look right at the dustcap, it is hard to see it. As long as the lateral shift isn't visible, mounting orientation can fix most of its visibility. Still, I would think a $275 woofer should have this issue licked.
InDIYana Event Website
Yeah that is disheartening. I think I have mounted ones with offset dustcaps so the droop is at the downward spot. Because of the normal viewing angles (IE looking down at the woofer) It can make it tough to spot, even if you know it is there.
Bingo!
InDIYana Event Website
In the VersaBox enclosure, 103dB:
Xmax at 103dB:
Vent Mach at 103dB:
It appears that these can take up to 78W/103dB before mechanical issues occur. The port is just touching that border before turbulence ensues, and the voice coil has not yet hit Xmech.
However, under a more normal 40W/100dB peaking, the Xmax (+15%) is good down to 23Hz before breaching xmax. That is just phenomenal capability for a slightly larger than average 6.5" woofer.
InDIYana Event Website
According to the Test Bench article about the 10", Vance said it had enough motor strength for 12-13mm of xmax, but the suspension limited it to 10mm.
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