"Parts upgrade" on crossovers -Any experiences?


I remeber upgrading the crossovers of a pair of B&W DM12's with esoteric resistors, caps and wiring (about 10 years ago). In the end I got a different speaker. The bottom end seemed improved and the highs were more delicate and smoother, but the midrange had lost some of the magic. I could not deal with the decreased midrange quality so I re-soldered most of the parts back to the crossovers but left the upgraded wire (the wire in there looked like tined copper and was tied with a Molex connector to the board!). I changed the parts since I felt that early 80's speakers could only benefit from higher quality parts and was worried that the cap values might be out of spec. I am currently using a pair of KEF 101 and I've been thinking about upgrading crossovers with Solen Caps, maybe some Caddok Resistors and Cardas or Kimber wire. The KEFs sound great but if I can get more out of them, I might give it a try. Anyone do similar upgrades with an increase in ALL aspects of your speakers performance...or have BAD results...or find the end result a mixed bag of better here, but worse there (like me)? Also, any input on what parts / brands to use and which not to use? Are Solen caps good choices (or are there others that work much better for this application)? Resisters Brands?
I am purposely leavig out the issue of active crossovers (don't want to find 4 identical monoblocks to run my speakers).
one_audiophile
Many of the "problems" that one runs into when modifying speakers are that the "high grade" replacement caps are not oriented with the proper "polarity". While some will question the validity of a comment that states that non-polarized caps can be installed with the incorrect polarity, please read on.

Caps have an inner winding and and outer winding. As such, one can orient two caps, which look the same and have the printing facing the same way, in the opposite directions within identical circuits. The end result is a fuzzy mess with a lack of focus and cohesiveness. Another common side-effect is blurring of imagery and an increase in harshness. As such, one should go to the trouble of "polarizing" the caps so that they all share common directionality prior to installation. Bare in mind that, just because the labels / printing on the caps are all facing the same direction, the caps may not share common polarities / connections inside the cases. There is a trick to finding the correct polarity and once you do this, you will instantly know what i am talking about. One can see the differences in polarity on a scope once you learn the "trick".

Once this is done, you will find that having all of the caps polarized in one direction will sound different than if you reverse the polarity of all of the caps within the circuit. In such instances, there is no right and wrong, so choose which orientation sounds best to you.

On top of that, caps used within speakers can take a long time to fully break in. Due to the very dynamic ( read this as being "sporadic" or "non-steady state" ) signals that are applied to them, the caps don't really "form" like those that are used in power supplies or line level signals that are relatively constant. As such, one can "form" the capacitors prior to putting them into a circuit using a signal generator of high amplitude and speed the process up drastically. Once you've done this, the differences in "sonic polarity" with the cap facing one way in the circuit and reversed will become more evident also.

Besides all of this, every wire and resistor will impose their sonic signature into the circuit. As such, it is best to use wires that you already know sound good with those speakers and to keep the legs of any component ) cap, resistor, etc... ) as short as possible and make a good mechanical connection prior to applying solder. In other words, the connection should be solid prior to applying the "electrical glue" aka solder. This helps to minimize the influence / sonic characteristics of the solder. If you don't do this, the solder becomes the conductor rather than the actual leads on the components.

Other than that, each product is built to a price point and most engineers / designers have their own likings. If you like a product and it was truly designed to be as neutral as possible, adding passive components that are even more "transparent" by nature will only improve the product ( if done correctly ). Otherwise, taking a product that has a "built in flavour" aka "colouration" and trying to hot-rod it can end up in something VERY different. Whether or not it is an improvement is up to you as an individual and how much you liked that specific colouration. Sean
>
Very interesting - as I posted in a recent thread, I had to have an under-spec'ed resistor that went bad "upgraded" on one of my Thiel 2.2's by the factory, whose tech stated that this particular resistor (at 1/4 watt) had caused many previous problems on this model. He just threw what he happened to have lying around (of the same ohm rating) in there instead - a 5 watt resistor of a clearly different type, and also gave me another one to install in my good speaker as a preemptive measure (he admitted that this wattage rating was actually overkill). I haven't done that yet, and this thread gives me pause. Maybe I should call back down to Thiel and see if I can speak to the head honcho himself by way of doing a little more research before breaking out the soldering iron. My one reassuring indicator so far - since I haven't yet re-broken in the fixed speaker, which also required two new drivers - is that the tech performed a quality-assurance anechoic test on the repaired speaker, and said it measured better (by which he presumably meant flatter, or within a tighter tolerance) than most examples of the model.
After reading these replies, I think that I will leave my crossovers alone. Sean and Rives have convincing arguments ( I've heard in the past about "breaking in" the caps and talk about the system aproach to crossover tuning ). I was just wondering if I was one of the few that had tried components upgrades with some NEGATIVE results. Thanks Albertporter for sharing your Snell experience (at least you got the Snells back to how they were). I will simply be happy with my current sound.
That's where I wouldn't mess up at all. There are a particular values placed and zillion times tested for a particular optimal crossover point.
All you might do is just ruin it to the different parameters and don't try to force yourself that your speakers sound much better after crossover mods(I know that many 'phools do) cause they simply won't.
You can experiment with electronic crossovers and bi-amplification doing much less harm and knowing that you're not wasting money for parts.
Post removed