hi Zvu - would you have values for that notch filter ? i want it to sound reasonably good and not "pop" the tweeter's coil.
You'd have to measure impedance and frequency response of your tweeter in a box and then i'll be able to simulate something for you. Fs of tweeter can vary by couple of hundred Hz - usually higher than lower. Any sim at this point would be a shot in the dark.
(I'm hoping the LCR Z-notch filter will reduce excursion below the passband - I can feel the dome move/vibrate a little bit on Johnny Cash "Songs Of The True West" at robust volume - that's a great album and beautifully re-mastered)
Hey Norm, CAT378 sounds pretty good with B102 and no woofer filter - I've got ~5.5uF of funky* cap feeding the tweeter. Its not overly hot runinng w/o any attenuation - maybe a bit mellow - maybe a bit like an Advent's balance.
(*3.3uF "Audiophiller", with 2-1uF Vishay DC-link parallel plus 2-0.1 Dayton foil parallel)
It would be interesting IF (?) a higher order filter could sound just as "good" and allow a bit more peak SPL
btw- I have it hooked up "plus to plus"
I think you may like this Morel. What are good albums to show a speaker's "coherency" ?
Hey Norm, CAT378 sounds pretty good with B102 and no woofer filter - I've got ~5.5uF of funky* cap feeding the tweeter. Its not overly hot runinng w/o any attenuation - maybe a bit mellow - maybe a bit like an Advent's balance.
(*3.3uF "Audiophiller", with 2-1uF Vishay DC-link parallel plus 2-0.1 Dayton foil parallel)
It would be interesting IF (?) a higher order filter could sound just as "good" and allow a bit more peak SPL
btw- I have it hooked up "plus to plus"
I think you may like this Morel. What are good albums to show a speaker's "coherency" ?
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with parts laying around - its a bit off target and too low of summed impedance - a larger inductor might get it - those cap figures are what's printed - its all kinda ballpark. I could try raising "R" .
CAT378 by itself - resonance ~600Hz
5.2R, 1mH, 40uF "Z-notch" , 5.2R, 1mH, 46.8uF "Z-notch", then sum of last filter with CAT378
what's a reasonable wire gauge for an air coil in this application ? - I'd like to keep it cheap
CAT378 by itself - resonance ~600Hz
5.2R, 1mH, 40uF "Z-notch" , 5.2R, 1mH, 46.8uF "Z-notch", then sum of last filter with CAT378
what's a reasonable wire gauge for an air coil in this application ? - I'd like to keep it cheap
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mellow may be due to the lack of wide dispersion as the freq goes up.
I noticed that when I overfoamed the rb75, awesome at arms reach, way less highs sitting 10' away.
eh, you just notice through watching movies or noticing lyrics when you aren't listening for them.
Lol, so yea, stop hunting for them and they will show themselves, like gekos or enlightenment.
And difference moving it forward and backward to line up step response ?
Overall, good to know out of the gate it seems good.
I noticed that when I overfoamed the rb75, awesome at arms reach, way less highs sitting 10' away.
eh, you just notice through watching movies or noticing lyrics when you aren't listening for them.
Lol, so yea, stop hunting for them and they will show themselves, like gekos or enlightenment.
And difference moving it forward and backward to line up step response ?
Overall, good to know out of the gate it seems good.
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yeah -its the first one of its type that I've tried in over 20 years - one before was semi-hard dome - maybe a Vifa. CAT378 seems to be pretty nice. I'll wire it up again without the notch and compare to a "Large" Advent. If I try a notch at 600, how thin can I go on the 1.25mH air coil wire gauge ?
a few inches back helped with harp and light soprano voice - gotta be careful as the tweeter might roll off. What's a sensible cheap wire for crossover parts to tweeter, etc? It does seem more mellow than some of my toys - maybe those are cranked up a bit on the top - I think is more mellow on that soprano than my Klipschorn - but the tweeter on a K-horn sets a good two feet in front of the midhorn driver. I have a fancy 5uF cap but no M8-1.25 pitch screws yet to terminate - faking it with cheap steel alligator clips, etc. - seemed a bit different than Vishay DC-link and glorious red "Audiophiler" cap
(Wima DC-link are said to be very good for xover with appropriate bypass caps - apparently takes a long time to get some Wima from Mouser)
(Wima DC-link are said to be very good for xover with appropriate bypass caps - apparently takes a long time to get some Wima from Mouser)
Ug, that means i need seperate tweeter box (to slide it back).
I know a cap seems to push a tweeter forward, and you need to be plus minus 1/4 wavelength at frequency. So 2khz is 6", so lined up at centers, 3" sweet spot.
B102 4th order 2.3ft3. Tuned to fs equal f3 around 50hz.
I'd not like to bring the woofer clear up to the top of the box, but i had luck with my b20 in 2' wide x 3' tall box with it at the upper edge. Maybe ok to do that if box is 1 x 1.618 ratios.
Maybe we should move this to a different morel thread.
Thank you for your graphs and going out on a limb.
I think this will be an excellent build for the money, and simplicity.
I'm thinking 4.6ft3 with 2 b102's but the rising Z may make a simple inductor for baffle step woofer not an option.
Any luck on notching b102's whizzer resonance ?
I know a cap seems to push a tweeter forward, and you need to be plus minus 1/4 wavelength at frequency. So 2khz is 6", so lined up at centers, 3" sweet spot.
B102 4th order 2.3ft3. Tuned to fs equal f3 around 50hz.
I'd not like to bring the woofer clear up to the top of the box, but i had luck with my b20 in 2' wide x 3' tall box with it at the upper edge. Maybe ok to do that if box is 1 x 1.618 ratios.
Maybe we should move this to a different morel thread.
Thank you for your graphs and going out on a limb.
I think this will be an excellent build for the money, and simplicity.
I'm thinking 4.6ft3 with 2 b102's but the rising Z may make a simple inductor for baffle step woofer not an option.
Any luck on notching b102's whizzer resonance ?
I've not tried yet to muck with B102 - maybe even a strip of bonded Dacron between the cone and whizzer would tame things (?) -
there's a chance CAT378 will work (?) flush mounted - my junk reflex box has B102 pretty far from the tweeter.
could this be of use? - it sure would drive parts costs up
it would be interesting if someone with good xover simulation ability would illustrate what benefit a LCR Z-notch really would do for CAT378 when using a single capacitor highpass vs no compensation filter. When PE re-stocks their 1.2mH 20ga Dayton air-coil, I'll give that a try.
2-B102 per cabinet would give some larger signal ability - even one B102 isn't shabby for a small driver and seemed well behaved past published xmax.
would a Zobel on the BSC B102 get what you want with a single inductor ? I wonder even what the whizzer does for B102.
there's a chance CAT378 will work (?) flush mounted - my junk reflex box has B102 pretty far from the tweeter.
could this be of use? - it sure would drive parts costs up
it would be interesting if someone with good xover simulation ability would illustrate what benefit a LCR Z-notch really would do for CAT378 when using a single capacitor highpass vs no compensation filter. When PE re-stocks their 1.2mH 20ga Dayton air-coil, I'll give that a try.
2-B102 per cabinet would give some larger signal ability - even one B102 isn't shabby for a small driver and seemed well behaved past published xmax.
would a Zobel on the BSC B102 get what you want with a single inductor ? I wonder even what the whizzer does for B102.
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in my extremely cramped space, here's 1/24 octave sweeps of B102 with mic at about 1 foot by itself, no filter -- then no filter but with a random torn strip of bonded Dacron between its whizzer and cone. I've a pir of ~14ga 0.56mH coils which could be paralleled for ~2K8 notch filter - want me to try that?
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maybe a notch for 2.5khz and 4.5khz.
Then again, the 4.5khz will be narrow dispersion than it may be very low 12' away from the speaker.
That peak at 2,500 doesn't look to bad actually.
And that's measured at a foot.
At 3' I bet that peak would seem even lower compared to under 1,500hz.
Did the tweet notch reduce its excursion ?
Then again, the 4.5khz will be narrow dispersion than it may be very low 12' away from the speaker.
That peak at 2,500 doesn't look to bad actually.
And that's measured at a foot.
At 3' I bet that peak would seem even lower compared to under 1,500hz.
Did the tweet notch reduce its excursion ?
I didn't get back to the tweeter notch - would like to try ~1.2mH/50uF and ~Re -- don't know the effect upon excursion at resonance (???) maybe some reader fast with simulators will make a comment. It seems like too much hassle to try two notches - their frequency might move when the mic position is changed. At the very least, I'll take a few sweeps with tweeter in place to see its level vs B102.
Yea, the cat378 may be similar spl, but 30 degrees and 45 degrees it is lower in the high end, thusly lower highs at couch.
Yea, the b102 may not need a notch at all.
On the morel, fs notch will lower excursion, see here.
Elsinore Crossover Discussion
Yea, the b102 may not need a notch at all.
On the morel, fs notch will lower excursion, see here.
Elsinore Crossover Discussion
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