Three way crossover question

[adason]

Sorry, i only read last post...when you hit button jump to new. Keep experimenting. But if you have cellphone/smartphone, you can measure.
All else is guess.

 

[henrylrjr]

What you do is not the way it should be done. Putting smaller and smaller resistance across the speaker is basically shunting an audio signal to ground.
But you are presenting lower and lower impedance to the amplifier. Not only this leads to higher distortion, but at higher power may damage amplifier.
If you want to attenuate some band after crossover going into speaker, use proper l-pad. It reduces the volume, but maintains constant impedance for amplifier.
See pic.
And btw what you describe 0.47 being louder than 2.2 ohm is nonsense.

I am using an L-pad. There is 5ohm resistor in series.

 

[adason]

Technically, its not l-pad. L-pad are two potentiometers in one, maintaining constant load to the amplifier.
But since you have 5 ohm before, your amp is safe.

 

[weltersys]

I am using an L-pad. There is 5ohm resistor in series.

As mentioned in post # 156, you are still ignoring (or are not listening for) the attenuated bass response of the upper woofer due to the series and parallel resistance you have added to it.

Best of luck with the ebay capacitor sales!

Art

 

[henrylrjr]

I'm very pleased with the midrange bass response. Sound of the upright string bass is well balanced with the upper piano notes.

 

[henrylrjr]

I don't know what the cause is but it's possible that the treble becomes dominant as the midrange goes below that level.


We discussed keeping the series resistor in place. As long as it is there it should allow experimentation.

Hi Allen,
I now understand how the resistor effects the sound. In the case of the resistor across the driver the lower resistance allows more of the signal to go to ground.

 

[AllenB]

Yes, that's a part of it. It also changes the Voltage on the series resistor.

 

[Mr Evil]

@henrylrjr Just to let you know: The link in your profile to www.hrcustommachining.com doesn't work - the domain doesn't resolve.

 

[henrylrjr]

Thanks, that link stopped working some time ago. I just removed it from my profile.

 

[henrylrjr]

The outboard XOs are finally done and I love the sound.

 

[henrylrjr]

I should probably solder all the wire joints and replace the wire nuts with shrink tubing.

 

[henrylrjr]

Thought I would share the schematic. Maybe it could provide some an idea of how to make an XO. The HF - to + and + to - is because the tweeter is reversed in this XO.

 

[shadowplay62]

I don't know if you made it intentionally, but the input of the woofer low-pass L3 should be connected to the Amp (+) connector and not on that side of the coil L2 of the Midrange. Basically, in your diagram the woofer sees a higher inductance (6.5mH) and the x-over frequency between WF and Mid is lower. The slope and the level defined by the coil L2 are slightly modified too. See diagram below.

 

[henrylrjr]

Your mark ups are not correct. The woofer only gets the sum of L2 and L3.

 

[mattsk8]

Your mark ups are not correct. The woofer only gets the sum of L2 and L3.

What he's saying is, in your schematic you also have the midrange going thru that 15 mH coil, according to your schematic your midrange wouldn't play much frequency above roughly 100 Hz. Either the schematic isn't correct or you aren't getting any vocals out of your midrange.

 

[AllenB]

It's hard to see but it's 1.5mH. This is a variant on a 2.5 way.

By cascading the two you get closer to 2nd order on the mid and 3rd on the woofer. Eg...

 

[mattsk8]

It's hard to see but it's 1.5mH. This is a variant on a 2.5 way.

By cascading the two you get closer to 2nd order on the mid and 3rd on the woofer. Eg...

View attachment 1089969

That makes more sense haha

 

[shadowplay62]

Your mark ups are not correct. The woofer only gets the sum of L2 and L3.

Sorry, got confused by the many schematics of this long thread and I did not notice the original filter topology was a 2.5 way.

 

[henrylrjr]

Vocals, trumpets and saxophones sound accurate and great coming through the midrange.

 

[henrylrjr]

That makes more sense haha

Caps in the final midrange filter are 5.6, 6.8, 5.1, 2.7 and 1.5 for a total of 21.7uF