L-pads and variable tweeter attenuation

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I have a pair of 4 ohm tweeters that need to be attenuated somewhere in the 3-6db range. I've just recently been told that I can use an adjustable L-pad to fine tune to my tastes. I checked out some of the units available at Parts Express and am left with a few questions.

1) I see units that maintain 8ohm or 16ohm. Does this mean that they will change what my amp sees from the tweeter as either 8 or 16 ohm and reduce output?

2) They all have wattage ratings. Which do I chose if my amp is rated at 35 x 2?

3) They have stereo and mono versions. Since I'm using 2 channel stereo, do I use the stereo version?

4) I realise that these are intended to tmporarily find the correct attenuation and then a fixed version can be produced. Any problem leaving them in place? Sound quality/imaging issues?

Sorry if these questions seem silly but until I get hold of a copy of the LSDC (not easy to find locally) I could use the advice.
 
1: The L-pads are designed for 8 or 16 ohms. Have to do some math to see what it would do with a 4 ohm tweeter. Probably work okay.
2: If it's between the crossover and the tweeter, you won't need the full 35 watt rating. Maybe 5 or 10 watts. OK, maybe 20. Depends on your crossover frequency.
3 yes, 4 no.
 
Thanks for the help. The L-pad will be in between the passive x-over and the tweeter. They are crossed at 3.5k.

Just to clarify, I'll be using two, one on the left channel, one on the right channel. Still use the stereo version?

My concern about the 4 ohm rating is that with no adjustment at all it'll show the amp something between 4 and 8 ohms, possibly reducing amplifier output and attenuating the tweeter by it's very exsistence in the signal path. Also I have no idea how much the L-pads adverstised at Parts Express are capable of cutting. 2db, 3db, 6db?

Thanks again!
 
The table found here
http://sound.westhost.com/bi-amp.htm
says something less than 15% of your power will be going to the tweeter. So if you're pumping 35 watts into your speakers, about 5 will go to the tweeter.
No, you wouldn't use the stereo version if you have one control per tweeter. The maximum attenuation from a variable L-pad is infinite. At full, it will not reduce the output but the impedance seen by the amp would be a bit lower, as you have two elements in parallel. I think this will work for you.
See http://www.cornell-dubilier.com/mpdf/cntl_in.pdf
 
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