Playing with crossover values

[VantheMan]

I was reading Peter´s article "The Next Step" , as published in Hi-Fi World regarding the definitive crossover for the WD25TEX speakers and I was struck by a line encouraging builders to experiment with the value of the resistor used in series with the tweeter inductor in that circuit so as to adjust what he called the transfer curve (Gawd knows ) of the Millennium tweeter.
Just wondered of anyone had done this; he mentions raising its value ( 2.2R) by as little as 0.5R to give a touch more warmth and vice versa ?
What wattage value for the resistor should I get ? any recommendations as to make ?

[John Caswell]

Hi,
I would suggest 5-10Watts as it is HF.
Make - goodness there are so many that others think are the greatest since sliced bread. I would try bog standard Welwyn green vitreous types initially as they are cheap or the square VTM types.
If you can get hold it then a 5-22R variable resistor fitted in place of the existing R and adjusted to your liking will allow you to experiment to your hearts delight. You then measure it and replace with a fixed type.

John

[bob orbell]

Hi Van, you have answered your own question here, buy making the resistor value larger, ie lets say 2.9R, the tweeter will receive less volts and will sound warmer, now if you change the resistor to, lets say 1.5R, the tweeter will now receive more volts and will sound brighter, it is all subject to your room and your personal taste. As for the wattage, if you change it must be the same as the one you remove.BOB

[VantheMan]

Thanks Gents, I´ll start looking for some variable jobbies. Sounds logical.

[Richard]

Hi Van, all,

Here's the article for anyone following,

http://www.hi-fiworld.co.uk/loudspea...next-step.html

I hope it's ok with Petercom and HFW to show the xover below (Ctrl and scroll to see it bigger),




The resistor is R5 and inductor is L2.

(L2 is given as DCR 0.9 ohms so check if your inductors weren't supplied by WD and take the total value into account when adjusting R5.)

You may find a suitable variable resistor otherwise get suitable values of wirewounds from Maplin.

I'd get 2 x 1 ohms (W1R is Maplins 3W or L1R is 7W). Change out the 2.2R for them for 1R or add them in series with the 2.2R to make 3.2R depending on which way you're looking to go and see if you can hear a difference. If you can then fine tune from there

[VantheMan]

Nice one, Richard. Even I can understand that.

[Phil Y]

Once you have settled on a value you like, you could try Mills Resistors. I have found them to sound a lot better than "standard" wire wounds but as John says, there are many others as well.

Phil.

[VantheMan]

Thanks Phil, I had thought of Mills but some say yes and some say why ?
What about the Soniqs caps in the original kit ? Any experience there ?

Cheers,
Chris

[Greg.]

Although I have fitted Soniqs capacitors for others in their kit, I have no long time experience of sound and how it changes as they burn in. I do however very much like Mills resistors, use them in my current KLS3 crossovers and would wholeheartedly recommend them. Wire wound and non-inductive, what's to go wrong! To me they sound great!

[Phil Y]

Hello Chris,

Sorry, I have no experience of the Soniqs caps although several people on here seem to like them. I have become a bit of a Mundorf fan the last couple of years. There are so many makes these days you can't really try them all !

Regards, Phil.