Upgrading crossover?

Has anyone done an upgrade to factory speaker crossover with better quality components and got good results?
I had opportunity to look at the crossover while upgrading friend’s PMC FB1 to + version, and I noticed that components were not of a high quality, inductors with ferrite core, electrolytic caps, resistors of 5%.
What are your thoughts of replacing these elements with better quality ones of the same value, inductors with air core (for example Alpha core Ribbon inductors), Solen caps, etc?
Always a good idea to upgrade if you are up to it. I've done about 15 different pairs with great results. Always make a quick schematic of the crossover so you don't confuse wiring and components. Do only one speaker at a time and try it first, then proceed if successful, otherwise use the unmodified crossover as the template.

If you are doing $300-$500 range the Solens are great. Above that go to the Auricaps. Rewire with better cable.

Might pack corners with rope caulking (Mortite)to dampen cabinet. If the speakers are biwirable, internally solder for only one set of terminals. Use good quality silver solder, not lead. Have fun.
If the speakers are more expensive, often times even if the parts seem cheap they have been handselected to meet close tolerances. However, I have always upgraded the crossovers on used or speakers I've purchased at closeout prices. Just changing the crossover caps and putting in good wire makes a large difference worth the 40 to 80 dollars spent. (kimber cable 8vs ,if thats the blue and black wire, was always made a a great hookup wire). Anyway the upgrades have always I have a pair of sound dynamics rts-5s that I modified, and there are fairly good pics of the crossove if u want to take a gander.
Please bear in mind that series resistance in inductors are a integral part of any serious cross-over design, so replacing inductors shoud be done with the outmost care. Other than that have fun.
Greetings, I now this is a little off your thread, but you also may want to consider upgrading your speakers internal wiring.

I recently rewired my Klipsch LaScalas', whose original wiring was still like new. I used DH Labs hookup wire. Total cost was about $70.00.

The improvement was considerable, I would have never believed that just upgrading wire could make such a difference. Happy Listening
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I have upgraded the caps, resistors and air core inductors on all three pairs of my Klipsch speakers and can tell you for a fact that I HEARD a tremendous difference in sound. I replaced the stock caps with Kimber Kaps, stock resistors with Mills non-inductive resistors, and stock air core inductors with Madisound.

I lived with all these speakers stock for about 5 years, so I was very familiar with the sound. What I heard after I upgraded the crossovers was nothing short of amazing. Trust me, I wasn't TRYING to hear something either to justify the less than $100 in parts cost.

Bottom line: better parts do make a difference.
Going external active crossover is not something I would be willing to do, considering all other components that will have to be removed/replaced, my main objective was to improve crossover elements, and it seems to be good idea based on feedback.

For Peter (PBN)

I have your SPXs. Is there anything you would recommend to do to the xover that would be an improvement? How about changing to better parts quality? I have no idea what you used, haven't been inside for a peek a boo.

When upgrading the crossover, the first ones to do are the series caps (caps that cross between + and -). The series caps are under more stress than the parallel caps, and have more impact on the overall performance. I've been using the ClarityCaps from e-speakers.com with good results, Tony Gee likes them which is good enough for me (http://www.humblehomemadehifi.com/Cap.html) And they're cheaper than all the other caps, sometimes much cheaper.

Adding bypass caps isn't a bad idea either. I have quite a few different caps I experiement with for bypass use. Here's a good site to read about different bypass caps http://www.ecp.cc/cap-notes.html I bought some of the Aerovox AFPS from electronicsgoldmine based on his notes, they were dirt cheap and perform very well. You can also find NOS Vitamin Q's on ebay all the time cheap, and they're nice performers.

For the inductors I don't usually touch them if they're air core, if they're ferrite core I'll consider replacing with an air core. But usually replacing the inductors simply doesn't have near the impact that caps do. Of course it all depends on where they are in the schematic.

Replace your sand cast resistors with good wire wound resistors, like Ohmite or Mills.

When I do a speaker, I do the whole thing ... including the enclosure. The best test of where a cabinet needs help is just using your knuckles. Knock on the box and listen for hollow sounding panels. When I find one, I measure the inside dimension and cut a 1" dowel rod to length. I put liquid nails on it, wedge it in real tight, and it always makes a huge difference. I also like to put bitumen sheet on the inside walls and then 'paint' over them and the entire insides with something like Cascade sound dampening liquid. After that routine, even the cheapest cabnets sound rock solid.

For rewiring to the tweeter and midrange I use a nice 14ga silver hook-up wire I found from North Creek Audio, the woofers and connections to the terminals get a good quality 12ga copper wire meant for car stereo amplifier power cable.

Another little trick I do is to put modelers clay inbetween the driver frame and the magnet assembly. I press it in there tight, as much as possible without blocking airflow out the back of the frame. Doing this can potentially stop resonances of the driver frame.
Hi Sashav,

Apologies for replying to a post that is now nearly 14 years old, but I’m engaged in some ‘loudspeaker archaeology’ and am taking a long-shot. I have some old FB1s that I’m in the process of upgrading to FB1+. This is difficult, as even PMC don’t know all of the details anymore. PMC helped by letting me know which tweeters to get & the crossover amendments (I’ve now done these); but nobody left at PMC remembers about the foam upgrade...

When you upgraded your friend’s FB1 to you remember what sort of foam (roughly) was used? Was it similar to the other foam in the enclosure? Roughly how much was there? And finally where did you put it? (Behind the mid/bass driver, or at the exit port?).

Sorry - lots of questions, hope you can help.

Best wishes & kindest regards,


Hy Darco!

Can you please send me what pmc let you know about the modification? And since then have you find out something about the foam questation?


Thanks a lot 



Go for it, keep the tolerances as tight as you can find, 1%. This way the speakers might match better giving you a better image.

ESR and DCR matter, a lot.

I suggest you buy a Dayton DATS so you can accurately measure these in components before replacing them.  Reducing either significantly will negatively impact sound quality.  Of course it will sound different, because you just altered the fundamental crossover.

If you want to do this correctly, and there are reasons to, measure the ESR and DCR of the caps and coils, respectively, as you go along.