Raising the While Flag on 604 Project

[Naimare]

Depending on one's listening preferences, room acoustics and system, varying (3R3 - 6R8) the value of 4R7 resistor would give wide enough range for tuning high freq. energy. There is no need to change 27R.

One cannot tune low/midrange with L-pad. It is done with series inductor value. Varying capacitor parallel to woofer would change only the upper part of woofers frequency response.

Vuki:waver:,

Can you expand on how one should go about varying the inductor value for low/midrange for the 604k? Lets's say you start with inductor value of 1.7 mH (like in JM's filter I use) for the low pass part. What happens if you increase or reduce the values?

Regards/Naimare

[vuki]

Vuki:waver:,

Can you expand on how one should go about varying the inductor value for low/midrange for the 604k? Lets's say you start with inductor value of 1.7 mH (like in JM's filter I use) for the low pass part. What happens if you increase or reduce the values?

Regards/Naimare

It's quite a simplification but; in a 12dB/oct. lowpass filter by changing L value (up to +/-15%) you mostly change the the slope of bass/midrange; higher L value slope goes down, smaller L value slope goes up. By changing C value you mostly influence the "knee" of the lowpass; higher C value = sharper knee...

[donaldpatten]

vuki :

I tried your hi pass XO section with my 605s , and it sounds great . What did you use for the coils ?

Todd:
Thank you for the Vocal Master plug . Limited BW, yes ," VOCAL " , everyone else has an amp and speakers. BTW to sound right they must be driven by a Shure : VA300, VA302 or PM300 , all of wich are current amplifiers. YES one VOLT in produces one AMP out. This makes the AMP into a equalizer, the output voltage follows the column impedance curve.

Don

[vuki]

vuki :

I tried your hi pass XO section with my 605s , and it sounds great . What did you use for the coils ?


Don

Nice to hear you like it - probably it works on 605 too, but it is designed for mantaray type horn- IIRC 605 has old, multicell type horn? It could be that the responses are similar enough. I used aircore inductors. Since both inductors on highpass filter are in series with relatively high valued resistors, Rdc of inductor isn't important -the cheaper the better

[Todd W. White]

Hey Don,

Yeah, we used to call them the "VocalBlaster" - and the speakers "Sound Collyum's"...

Really quite inventive, though, wouldn't you say?

[Seadweller]

It's quite a simplification but; in a 12dB/oct. lowpass filter by changing L value (up to +/-15%) you mostly change the the slope of bass/midrange; higher L value slope goes down, smaller L value slope goes up. By changing C value you mostly influence the "knee" of the lowpass; higher C value = sharper knee...

Vuki: I believe you mentioned that your XO was designed to address the rising output of the woofer at higher frequencies, which seems to be a primary cause of the "beaming" I'm experiencing...Is there a way to change any of the XO values to "control" the amount of output in the range of frequencies where the beaming occurs?

[vuki]

Hi Seadweller,

I don't understand your question, but using my crossover there shouldn't be any beaming.

[Seadweller]

Hi Seadweller,

I don't understand your question, but using my crossover there shouldn't be any beaming.

Sorry, I know very little about crossovers, so my questions are probably strange, so I'll ask it in a different way; similar to changing R3 (4R7) on your XO to increase/decrease high frequency energy, is there a component in the bass driver section of the XO that could be changed to increase/decrease the amount of energy from the woofer near the crossover frequency?

Hopefully, this makes more sense!

[aditya]

Sorry, I know very little about crossovers, so my questions are probably strange, so I'll ask it in a different way; similar to changing R3 (4R7) on your XO to increase/decrease high frequency energy, is there a component in the bass driver section of the XO that could be changed to increase/decrease the amount of energy from the woofer near the crossover frequency?

Hopefully, this makes more sense!

There are two aspects to your question here

1)-The energy coming out of the woofer & the tweeter need not be adjusted with two separate controls, as they are relative to each other, and by controlling only one of them does the job. As the woofer deals with most of the wattage involved, it is wiser and cheaper to control only the tweeter.

2)-The frequency respose pattern control of the woofer and tweeter at the cross-over-point, which is probabely the actual intention of your question, is a totally different thing. Here also mostly the choice of a contour control is usually given only for the tweeter, as our aural sensitivity usually is always in the area where the tweeter operates. The woofer is usually contoured/crossed-over in a fixed manner depending on the type of driver choice and type of application etc. etc. One can match and use any driver with another any other driver. But it is always better to have two units of similar sensitivity and a FR which is easily mate-able, otherwise one loses efficiency.

Now coming to "Vuki's" crossover, it has already taken care of the typical midrange brightness of the woofer, by reducing it and tapering it off with a slope starting much earlier in it's frequency response curve. This is done by the 3.6mH and 15mF. The tweeter also is similarly treated to dampen the brightness. So now only remains the choice of a HF control for the whole system. You can do that by varying the value of R3 between 3R3...to...6R8, as already suggested by him.

Aditya

[vuki]

Thanks Aditya!