Tweeter attenuator resistors

[Ant1-Hero]

I have been playing withdifferent resistor values on my speakers and I found this guide on the net, I have seen a few different methods from simply placing a resistor on the 2 + terminals, which to me would seem to throw off the impedence on the positive side. Using them in parallel with the tweeter running from + to -, or making an L shape with 2 resistors, Im not sure which is the correct way either, can someone tell me if this guide is on the right track

http://reviews.ebay.co.uk/Tweeter-Attenuator-Resistor-Guide?ugid=10000000004030106

Thanks

 

[SaSi]

Of all the places on the net, I never expected to see such a guide on ebay...

Anyway, the general idea is correct although I haven't checked the table with R1/R2 values against attenuation.

In - perhaps - simpler words, what you want to achieve is to have the crossover still see an 8 ohm nominal load (otherwise the crossover might become imbalanced) and still have some attenuation to the tweeter.

To do that you need to have a divider with 2 resistors. The attenuation is determined by the ratio between them. Since you can freely select resistors giving the same ratio, the values are chosen so that the overall resistance of the 3 resistors (R1, R2 and Rdc of the tweeter) add up to the nominal value.

 

[HTHMAN]

Interesting. I have a pair of speakers that I need to pad the tweeter down about 3dB or so. I was going to add an l-pad but just might give this a try.

 

[Ant1-Hero]

Ifound out that my tweeter is only 4 ohms, but Ll the lpads i found are 8 ohm, can someone tell me by using the guide what value the resistors should be for R2

 

[Ant1-Hero]

I found the values for 4 ohm tweeters

(dB)(ohms) R1(ohms) R2(ohms)
* −3 4 1.17 9.70
* −6 4 2.00 4.02
* −9 4 2.58 2.20
−12 4 3.00 1.34
−15 4 3.29 0.87
* −3 8 2.34 19.39
* −6 8 3.99 8.04
* −9 8 5.16 4.40
−12 8 5.99 2.68
−15 8 6.58 1.73

 

[Renzor213]

I've padded down many tweeters added on to car audio systems and always used a single resistor in front of the tweeters crossover network. Putting it between the crossover and tweeter will change the crossover frequency, and not what you're wanting. There's also the high tech approach like what I did on my family rooms HT rear flush ceiling surrounds. Taped a couple layers of paper towling over the tweeters, and works fine.

 

[HTHMAN]

There's also the high tech approach like what I did on my family rooms HT rear flush ceiling surrounds. Taped a couple layers of paper towling over the tweeters, and works fine.

That is not a bad idea. I may tape a layer or two of cloth over my over-achieving tweeters and see how it sounds.

 

[Ant1-Hero]

I've padded down many tweeters added on to car audio systems and always used a single resistor in front of the tweeters crossover network. Putting it between the crossover and tweeter will change the crossover frequency, and not what you're wanting. There's also the high tech approach like what I did on my family rooms HT rear flush ceiling surrounds. Taped a couple layers of paper towling over the tweeters, and works fine.

Isn't that how an L-Pad works? This simply makes the amp not see the resistance on just the + side.