N-500-E

I would be deeply appreciated if anyone can give me some information regarding N-500-E crossover. I only got info. of N-500-D, and it seems to be matched for 802.

shensc127,
I'll email you a PDF of the schematic.
Jeff

Dear Jeff, Million Thanks! [email protected]

Jeff, I got the doc., Thanks! It seems to be crossed at 500Hz for 8ohms driver, but I would like to use for 288-16K which is 16ohms.

Jeff, could you also send me a schematic of the N-500-E. Thank you, Reed

shensc127,
A high pass filter formed by 4uf and 5.4mh has an F3 of 1083Hz, regardless of the impedance of the driver. With a 16 ohm load it has a fairly low Q of .43, meaning it is not peaked above F3 but flattened out somewhat. (A Butterworth has a Q of .707) An 8 ohm load in this circuit would have a very low Q (.21), so the filter was probably designed for 16 ohms.
For a woofer, the low pass filter of 5.4mH and 18.9uf has an F3 of 498Hz with a Q of .95 using a 16 ohm load.
Hope this helps,
Jeff

Jeff, Thanks! Could you explain the definition of "F3"? I think that the crossover is for specific drivers. The high Q of .95 for woofer is good for bass, but I wonder that would be a greater the peak in response. With a 8ohms load it has a Q of .47 which is close to the Q of high pass. Is it possible to get more flat response at the crossover frequency?

shensc127,
F3 is the frequency where the filter attenuates by 3dB.
Jeff

Thanks!

Thank a lot!

Jeff,
Could you also send me a copy of the N-500-E xover? I would like to see exactly what you are refering to in these posts. Are your results actual measured or simulated?
Thank you,
Richard C.

rchristianson_at_mindspring_dot_com

Jeff, Many thanks. Reed

Richard,

The PDF is on the way!

My results were calculated. I used a TI handheld and calculated the resonance of a second order filter, and the Q of a second order LC circuit, using the N500E values.

Jeff

Hi All,

I created a bit of confusion with my post about F3 above. I should have said that it's a filter's resonant frequency, (product of L and C), not F3, that remains the same at differing load impedances. It's the Q, or shape of the "knee" of the rolloff response, that changes with load impedance. While a filter's resonant frequency designates its crossover frequency, differing Qs definitely affect at what frequency the filter attenuates by 3dB. Most symmetrical audio filters lie in the Q range of .5 (Linkwitz-Riley) to .707 (Butterworth), and their combined power and frequency responses are well documented. BTW, Q is easy to calculate: Q= [(R?C)/L]?

Sorry for the confusion.

Jeff

Jeff, Do you have a schematic of the Altec N-800F crossover? If so, could you email it to me? Thank you. Reed

Reed,

Sure don't. Send me a copy if you find one.

Jeff

Hi,
I lost the schematic for the Altec N-500E. Could anybody send it to me? Thank you. [email protected]