Modifying Crossovers

I think the seductive part about upgrading crossovers (not modifying the network) is that those of us who have done it have heard substantial improvements.

I am of the opinion that I can more easily hear improvement in sound by upgrading parts in key areas (i.e. loudspeaker crossovers, coupling capacitors and output capacitors in amplifiers) than I can spending significant money on cables. Yes, I do think cables make a difference, but after I use good quality cabling I can’t experience as much benefit from going further.

With capacitors, in particular, if they are directly in the signal path or if they are linked to filter power supply, I believe that I can readily hear differences.

I once bought a Musical Paradise preamplifier for the sole purpose of using its internal "binding post" style terminations for coupling capacitors. This was brilliant by the OEM. They placed a slot for the cap on the PCB, much larger than what they supplied, and put a binding post at each end of the capacitor location. With a turn of the hand (just like tightening a binding post on a speaker or amp) you could insert the leads to new capacitors! This was so much fun and enlightening.

I also give props to the Amp Designer as they were acknowledging how different capacitors can sound.

Other examples of OEMs recognizing this are those that offer capacitor upgrades in their speakers and amps. I know Atmasphere and Modwright (I really respect those guys too) do that and a host of speaker manufacturers, though not many to my knowledge.

AudioNote and Elekit encourage users to upgrade or swap.

When I sell my used gear that I’ve upgraded this way, I disclose it to the buyer and tell them I have saved the original parts or have resourced them and can replace them if they want. Buyers who get it typically take the upgrade and old/spec’d parts. There’s no question a 1.50 film cap made in Taiwan often used in children’s electronics is (a) used in some awfully expensive products (I’m looking at you Harbeth); and (b) a nice Wima, Nichicon, Audyn, ClarityCap, VCap, etc. is better. [In fairness to Harbeth, I have seen photos where they also use what look to be beautiful Clarity Caps made in England--nice!]

Finally, I think those of us who have cracked open gear or built gear have learned many of these things firsthand. It’s not similar to anything else--cars, instruments, etc.

With high end audio, I see there is an inherent fear about messing with the design, hurting resale, and voiding warranty. Those are legitimate concerns, to a point, which can be mitigated or removed.

The charming and super knowledgeable Eve Anna Manley of Manley Labs (and her team) invited conversations with me about my upgrades--and they were not about voiding my warranty. Ms. Manley told me that if I liked my caps (linked to the RCA outputs) to use them--they’re great. But she also told me to experiment as they did. She said they spent countless hours listening to caps and thought the brand they chose (I think it was multi-cap or sonicap) worked really well in this amp. She said the same thing about tubes--they loved basic Eletroharmonix in this preamp, but she encouraged me to experiment.

I think one reason we don’t see manufacturers offering swap and play binding posts for capacitors is that there can (and typically is) huge amount of current running through these and the user would need to discharge the current before popping them out. That involves too much liability. But theoretically (if it was as safe as changing a cable), I think many would offer it.

Great topic!

@ervikingo 

A few years back, Paul McGowan at PS Audio, recapped his IRS-V speakers.  Paul asked for Arnie NuDell's help with the project.  Arnie recommended Mundorf capacitors.  The Mundorf EVO Oil caps, that I mentioned, are very good for the money.  Clear, clear, and very transparent.  They helped create a palpable midrange, when I used them for a speaker recap.

Good luck. 

@gdnrbob

I would be highly suspect of anyone who thinks they know more than the speaker designer. If they know so much, why haven’t they designed their own speaker.

My 2 cents...

It’s not about claiming to know more than the designer, it is a matter of getting around the marketing price point limitations of the speaker. For the manufacturer to move from caps that cost less than a dollar each, to ones that cost $5 or more, ends up raising the price at the consumer level by much more.

The fact is, that the vast majority of speakers at low to moderate prices, are loaded with cheap capacitors, sand cast resistors, iron core inductors, that compromise the capability of the speaker. You’d be surprised how many well respected speakers, even though they may still sound good, could still sound better with better crossover components. 

What is being discussed is, swapping out the same values, with the same values. but better quality caps and resistors. I have been doing this for years, and the results are always improvements. Usually more detail, and bigger, more defined soundstage. Sometimes it is more than subtle.

But yes, many times people do know more than the designer.

Case in point: GR Research upgrade kits for Klipsch RP-600M’s with redesigned crossover. What is an unlistenable speaker for me, becomes a reasonably good one after the upgrades.

@stimpywan Thanks!

I have found some rather expensive speakers that look expensive and fitted with beautifully machined spikes to give the impression of great care and engineering chops, but have cheaped out on the XO components which are hidden from view. Push-on connectors are used on the internal wiring to speed up assembly and other sound limiting short cuts are taken. All this cost saving is doing the resultant sound no favours.

Something mostly overlooked either from ignorance or deliberate acceptance is the orientation of the inductors. If two coils are close to each other there will be coupling, this is how transformers work, where they talk to each other causing congestion and smear. Keeping them far apart helps but of course will require a larger platform causing even more problems. Another reason that the coils are not optimally aligned is because one of them needs to be mounted, not lying flat, but upright on the rounded part which makes mounting it more difficult and time consuming.

If they are mounted correctly then they can be placed close to each other with virtually zero coupling. This happens when they are positioned as two links of a chain would lie.

Then there is the internal wiring, nasty sand cast resistors and the almost exclusive use of PCBs. Yes, there is much that can be improved. We are not talking about redesigning the XO circuit but improving what is there by replacing components with same value but better parts.

When I work on optimising the XO I endeavor to remove any terminals using brass. Those great looking chunky speaker terminals are bad news. Usually the brass, IACS about 27%, is first plated with nickel, IACS about 24%, which polishes to a high finish, and then gold plated. The polished nickel allows for a very fine looking and attractive finish. So, many dissimilar metals playing havoc with your precious audio signal. The push-ons are also brass!