Hey guys, I'm looking at building speakers similar to the 3way HiVi speakers shown here. DIY 3-Way Hi-Vi Tower Loudspeaker Project - 1.618 How do I change the treble crossover + lpad circuit, so I can add in a knob that controls treble gain. I have no experience with voltage dividers, so any help would be appreciated.
Something stinky is in the air, I think that other members have addressed the bad crossover already.
My opinion if you want to start your diy with this project, first take out (erase) the RP1/RP2 on the woofer circuit.
1.618 - DIY 3-Way Hi-Vi Tower Loudspeaker Project (Page 2)
You can use then a variable Lpad if you substitute RP1/RP2 on the tweeter or mid circuits.
To make sure you have a workable crossover/speaker with the least of mistakes I would simulate it finally with measurements or FRD's/ZMA's from drivers being used.
My opinion if you want to start your diy with this project, first take out (erase) the RP1/RP2 on the woofer circuit.
1.618 - DIY 3-Way Hi-Vi Tower Loudspeaker Project (Page 2)
You can use then a variable Lpad if you substitute RP1/RP2 on the tweeter or mid circuits.
To make sure you have a workable crossover/speaker with the least of mistakes I would simulate it finally with measurements or FRD's/ZMA's from drivers being used.
Thanks for the reply, and sorry if this circuit has been address in the past, but I wasn't really looking to "fix" this crossover. I wanted to know more about voltage dividers in general, perhaps using this circuit as a reference. So now my question to you is why would you remove the lpad from the sub? How does it's remove change the ohm load presented to the amp? And what calculations do I need to make on the treble lpad to ensure I'm selecting the correct part? I'm looking more for learning the theory than simply, "do this because it will work."
formulas for L pads here:
L pad calculator - attenuation dB damping impedance decibel loudspeaker speaker voltage divider - sengpielaudio Sengpiel Berlin
Baffle step correction formula here:
http://www.quarter-wave.com/General/BSC_Sizing.pdf
L pad calculator - attenuation dB damping impedance decibel loudspeaker speaker voltage divider - sengpielaudio Sengpiel Berlin
Baffle step correction formula here:
http://www.quarter-wave.com/General/BSC_Sizing.pdf
I don't see much wrong with that crossover at all. Whilst you don't often attenuate a bass unit, there are good reasons for doing it on occasion.
To answer the question, an adjustable L-pad is a clumsy device. However, an adjustable resistor can be used with a change of layout.
The treble filter becomes a 2.2R resistor in front of a 3.9uF capacitor followed by a the same 0.3mH shunt coil.
Now replacing the 2.2R with a 4R adjustable resistor, or rheostat as us oldies used to call them, gives you plus or minus 2dB on the tweeter.
Or to look at it another way, shorting the 2.2R gives you +2dB, and replacing it with 4R gives you -2dB on tweeter level. 🙂
Try modelling it, if you are interested: Downloads
To answer the question, an adjustable L-pad is a clumsy device. However, an adjustable resistor can be used with a change of layout.
The treble filter becomes a 2.2R resistor in front of a 3.9uF capacitor followed by a the same 0.3mH shunt coil.
Now replacing the 2.2R with a 4R adjustable resistor, or rheostat as us oldies used to call them, gives you plus or minus 2dB on the tweeter.
Or to look at it another way, shorting the 2.2R gives you +2dB, and replacing it with 4R gives you -2dB on tweeter level. 🙂
Try modelling it, if you are interested: Downloads
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