[I.Greyhound Fan]

Hi, I have a question about upgrading a resistor in a crossover.

There is a sandcast resister in a crossover that I am upgrading.  It is 3.9 ohms 7 watt.  Can I replace it with a 4 ohm resistor without causing problems?  I plan on using a Mills MRA 4 ohm 10 or 12 watt.  I believe it is in the tweeter circuit.

Thanks,

Larry

[Tyson]

Yep, that's fine.  All parts are sold with a +/- 10% variance, so .1ohms is within that range.

[Wayner]

And the benefit would be.......?

[I.Greyhound Fan]

And the benefit would be.......?

The benefit would be for something for me to do.  I have a couple of pairs of bookshelf speakers (PSB B6 and Monitor Audio S1) that I want to replace the caps and cheap sandcast resistors for fun to see if I can improve the sound.  I don't expect much from the resistors but when I swapped out the cheap sandcast resistors that I was using to attenuate the tweeters in my Magnepan 1.6's with Mills or Duelund (same values of course) they both improved the sound in different ways and it was not subtle.  And my experience with swapping caps shows that they can and do sound different.

[richidoo]

The Mills definitely allow more information through, so it's a worthwhile upgrade.

The only downside I find upgrading cement or even metal oxide to Mills is the additional information Mills provides can be a little distracting, it almost sounds louder, so I usually choose the next highest size Mills over what I'm replacing to restore the musical balance. Thankfully, they come in small increments so it is easy to fine tune. From what I see there is 4.0, 4.2, 4.3, 4.5 so you're covered! You're fine to bump the 3.9 to 4.0, the difference is probably too small to notice. I would also buy the next biggest size 4.2? to try in comparison. Just clip them in while testing so you can return whichever you don't like.

Try red Jantzen Superior-Z for the caps, if they will fit. Great value, imo.

[I.Greyhound Fan]

The Mills definitely allow more information through, so it's a worthwhile upgrade.

The only downside I find upgrading cement or even metal oxide to Mills is the additional information Mills provides can be a little distracting, it almost sounds louder, so I usually choose the next highest size Mills over what I'm replacing to restore the musical balance. Thankfully, they come in small increments so it is easy to fine tune. From what I see there is 4.0, 4.2, 4.3, 4.5 so you're covered! You're fine to bump the 3.9 to 4.0, the difference is probably too small to notice. I would also buy the next biggest size 4.2? to try in comparison. Just clip them in while testing so you can return whichever you don't like.

Try red Jantzen Superior-Z for the caps, if they will fit. Great value, imo.

Thanks, I will buy a couple of values on the resistors, they are cheap enough.  I am using Clarity CSA caps in the PSB's to replace the cheap electrolytics.  The Xover board is small so I am having to mount the caps off board which I know is not ideal but it should make a difference.  I will have to do the same for the MA S1's.  If I used these speaker more, I would put some Mundorf Silver Supreme caps in them but  that would probably cost more than the speakers.

[richidoo]

Thanks, I will buy a couple of values on the resistors, they are cheap enough.  I am using Clarity CSA caps in the PSB's to replace the cheap electrolytics.  The Xover board is small so I am having to mount the caps off board which I know is not ideal but it should make a difference.  I will have to do the same for the MA S1's.  If I used these speaker more, I would put some Mundorf Silver Supreme caps in them but  that would probably cost more than the speakers.

Clarity great choice. Better imo than silver. Remember the drivers are also built to a cost, and the low resolution xo parts are deliberate ingredient in the intended voicing. Upgrades always reveal some new ugly along with the new beauty.

Longer cap leads to allow for larger caps is no problem.

[I.Greyhound Fan]

Clarity great choice. Better imo than silver. Remember the drivers are also built to a cost, and the low resolution xo parts are deliberate ingredient in the intended voicing. Upgrades always reveal some new ugly along with the new beauty.

Longer cap leads to allow for larger caps is no problem.

I am quite aware that I could ruin the sound as the speakers and parts were voiced as a whole.  I can always put back in the old parts.
I wish I had the understanding and ability to measure the frequency response and to replace the coils.  It was so much easier cap roll in the Pass B1 preamp that I built.