tweeter attenuation

[bostarob]

What can I use other than the adjustable Lpad from partsexpress to attenuate my tweeter about 2dB. I don't care for adjustability, unless it is a high quality design.
Thanks,
andy

 

[tomcat]

I presume you are talking of an 8 ohm tweeter; try 1.5 ohm in series after x/over on + side and 33 ohm parallel between + and - terminals.
tomcat

 

[Morello]

Att.

Implement a resistor in series with x-over.
Place between terminals and x-over.

 

[bostarob]

it is 6 ohm tweeter (i should have mentioned that).
how does one come up with what size resistors to use and where to put them? Is there an equation, or is it just experience?
Thanks for your help.
andy

 

[tomcat]

A 6 ohm tweeter will be 8 ohm under drive conditions... So the 'L' pad I suggested earlier will work.
tomcat

 

[JoeBob]

bostarob there are equations to find such things out. ESP has a good article about passive crossover design, it's mentioned in detail there. I'd reccomend you read it, it's a good read.

 

[bostarob]

Thanks guys
i think I've got the situation under control.
-andy

 

[mrfeedback]

Advice I have been told is that if you need to attenuate the hf driver, the series resistor should be before the hf filter if it is 12 dB/oct or greater, so that the filter is working into the driver, and not resistor and driver.

Regards, Eric.

 

[sianturi]

Hello Eric,
IMHO placing resistor in series *before* the filter is not "amplifier-friendly". This is because the ampli will drive a higher impedance of load. As for me, I would avoid this type of adjustment.
The series resistor after the filter will sure change the frequency response of the filter.... but there is a parallel resistor to compensate the additional impedance due to adding series resistor... so roughly, the frequency response of the filter will stay the same.

-sianturi-

 

[mrfeedback]

Filter Logic.

Hello sianturi, the logic of what was explained to me is this -

1 - Amplifier - reactive filter - resistive pad - tweeter, is different to
2 - Amplifier - resistive pad - reactive filter - tweeter.

I was told that for transient performance circuit 2 is preferable.

Presumably circuit 2 is flatter impedence characteristic also.

Regards, Eric.

 

[tomcat]

What you are trying to do is adjust the output of the unit in question from say a 92dB one to 90dB without altering any other characteristic of the drive unit, before any filter is applied, therefore the 'L' pad is always across the driver terminals before the filter itself. This is the way I've seen it applied in every instance I have come across....
tomcat

 

[bostarob]

I have done a little more research, and concluded that I need to drop the tweeter 4 dB. I already have a 2nd order crossover wired, all that needs to be done is attenuate the tweeter. With more research, I got resistor values of 2 ohms for series R1 and 10 ohms for parallel R2. Before I order, will I have to change the already in place crossover components, and do these values seem to be correct?
-andy