Can someone help me design an attenuator?

[Boscoe]

I need one for each of my 2 way moniters, with a flat sweep the bass is considerably lower volume so I have to have the bass turned up on my preamp which I don't like. The problem is I have no idea to how much I need to 'quieten' the tweeter to meet the woofers volume. Both drivers are a 8 ohm and are crossed at 3KHz.

Thanks
Boscoe

 

[Dr_EM]

Padding the tweeter won't have the same effect as the bass lift control on your pre-amp. The control on your pre-amp probably boosts around the 100Hz and under range, if you pad the tweeter you'll effectively boost 3kHz and under, it will effect a lot more than just the bass end! Why do you dislike using the tone control if it does what you want it to?

 

[Boscoe]

It's not vital but I like the speakers to have a flat response then change the the tone control. Don't know really just how I want them!!

 

[David Gatti]

Open up the speaker and tell us what's in the crossover.
Best approach will be to increase the resistor value in series with the tweeter.

 

[wakibaki]

I'd take aboard what has already been said, but for future reference, just google 'speaker attenuator calculator'.

L-Pad (Driver Attenuation Circuit) Designer / Calculator

w

 

[Boscoe]

This is the crossover I am using:

 

[David Gatti]

OK, that 2.5 ohm/12 ohm resistor combination is giving about 3.5dB attenuation to the tweeter..

I suggest you reduce the 12 ohm resistor to 8 ohms and increase the 2.5 ohm resistor to 3.5 ohms. That will give about 5.5 dB attenuation (i.e. an extra 2 dB), without altering the 3kHz crossover point.

 

[giralfino]

Just a few questions:
is it a commercial speaker or a diy one?
the 300-500 Hz region is also lower volume than the treble?
In my limited experience I would say that there isn't a correct BSC.
Ralf

 

[Boscoe]

It's a diy build. I don't know what BSC is?

 

[giralfino]

BSC = Baffle Step Conpensation
For an explanation of the baffle step effect see (for example): Baffle Diffraction Step
Here you can find a useful (an free) software that can simulate the effect: Baffle Diffraction Simulator
The compensation of the effect is done primarily with the main woofer inductor, for you that means you have to rework the entire crossover.
Ralf

 

[Boscoe]

Okay thanks for the info and I have read it and it sounds exactly right for what I have but the simulator dosen't work as I have the newer version of excel. How could I work it out?