Hi guys, this is my first post here trying to desing a small speaker base on tang bang w4-616s and dynavox tweeter that needs an l-pad attenuator (tweeter sensitivity is 94 db and woofer is 88 db) . I was using winISD alpha software to model the box, but I'm not sure of the crossover values that I got. L1=25.72mh ; C1=401.92; L2=0.6mh ; C2=9.38 and resistro vaues are R1=46.89 and R2=94.45 please need your help !!
sreten.
hey guys please dont overlook BSC.
BSC is usually 6db but if the speakers are close to surfaces (walls, floor) then you can get away with less.
i'd say practically you'll be looking at a speaker that is 85db. (88db-3db for BSC).
that means you have to drop the tweeter to 85 db. also small parallel resistors distort the sound too much so try and stick to a parallel resistor above 10 ohms, preferably in the region of 20 ohms.
92-85=7db the calcullator on lalena.com will help.
BSC is usually 6db but if the speakers are close to surfaces (walls, floor) then you can get away with less.
i'd say practically you'll be looking at a speaker that is 85db. (88db-3db for BSC).
that means you have to drop the tweeter to 85 db. also small parallel resistors distort the sound too much so try and stick to a parallel resistor above 10 ohms, preferably in the region of 20 ohms.
92-85=7db the calcullator on lalena.com will help.
Assuming a two-way design where the mid-bass is being used up to say, 3000Hz. wouldn't that just cause a padded down mid-range? Considering, if we take into account for BSC then, we would want to remove it's effects in the lows and not the mids or highs. In my past experience, I haven't taken BSC into account and have had admireable results. I'm open to suggestions none the less.
Hey guys remenber I'm a newbie. First, what is BSC? I'm going to crossover at 4500 (tweeter response is 1500-20khz and woofer w4-616s is 70-14khz) woofer sensitivity is 88db , tweeter is 94db, I did the attenuation for this one R1=3.99 OHMS R2=8.04OHMS using 2 way second order I got L1=25.72, C1=401.93, L2=0.6, C2=9.4 . How do you see those numbers. Thanks
Baffle Step Compensationporfi4ever said:
Simplified version:
Below a certain frequency (which depends on the width of the speaker's baffle), sound waves tend to "wrap around" the speaker rather than projecting out into the room. This results in approx. 6 dB less perceived sensitivity below the cutoff (gradual, not a sharp dip). You compensate by shelving down the higher frequencies.
More info
JeremyD said:
agreed that is why i suggested padding the tweeter to 85 db (88-3) instead of 82db (88-6) as would have been in an anechoic chamber.
in the real world we keep our speakers close to boundry walls. close usually means 3 ft or less. and this supports the upper midbass and hence compensates a bit for BSC.
please note that BSC is an approximation. you go nuts trying to make a XO that will compensate for every driver and room anamoly. after a while the cure is worse than the diesease.
7-9db (depending if the tweeter is 94 or 92db sens) of attenuation is what the Lpad should provide. any Lapd calcualtor will do this. try www.lalena.com i think they have a good online one.
porfi4ever said:
what software did you use?
L1 and C1 look odd. in any case the components will be very expensive.
the rest look like a good starting point. i assume L1-c1 is the woofer xo and l2-c2 is the tweeter xo.
Q: why 2nd order. ry 1st order at 4.5k the tweeter will be ok for most applications.
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