Modifying Crossovers

I just read a post about changing resistors and caps in the new Borresen X3 speakers. I am curious why there is interest in changing the components in a brand new speaker. I also am curious if it would make them better than why didn’t the designers put a better component in the first place. Just a thought and scratching my head. Have a great day.


It is fairly well known that even in expensive speakers, there are crossover components that are not the best quality, usually because the company that is making the speaker is trying to keep a good profit margin. It is then tempting for an owner to see what improvements might be gained by swapping them out for better parts. On the other hand, a lot of owners don't do it because the warranty could be voided, and also if they try to resell them, the buyer won't want speakers that have been modified in any way.

Another explanation is that some people have an insatiable urge to "customize" their gear. This makes it unique to them. 

To get a crossover with high end components you'll have to spend $100k or more.  I am currently building new external crossovers for my speakers.  I spent $2300 on caps, resistors, and inductors.   Here is a photo of the final layout completed just last night.

There is no way I would mess with factory Crossover of New Speaker, UNLESS many people documented the OEM made a mistake and problems resulted. 

The crossover looks like simple design nice quality to me

OLD Speakers, I would have my friend check the crossover for out of spec parts, replace them with the idea or restoring 'original', not 'let's upgrade them".

He has two pairs of JSE Model IIs. restored one pair's few out of spec parts. 'Upgraded the heck out of the other pair. We both prefer the simply restored pair to the upgraded pair.

It's very hard to deny the bias of it's better right! he's like me: not necessarily so.

Vintage parts might have been +/- 5%; newer ones, same values are probably tighter specs, say +/- 2%, not going to improve the sound, just typical modern production.

@falmgren ,

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...


Well, if you know what you have and what you want.

For isntance, Focals have good components, but I like Mundorf MKP's better than the Solens they use in the mid to low end models.

Wharferdale speakers can sound really really good with some better tweeter caps.

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.


Heh, well I have made several sets of speakers but I don’t claim to know MORE than they do, but maybe have different tastes.

Modding a speaker with careful application of the right caps is like adding hot sauce to a really good soup.

Some I wouldn’t touch, at all. Top of the line Magico and B&W use top of the line Mundorf caps. NOT my favorite, but in both cases the caps are absolutely tied to the sound quality. Once I start playing around in the crossovers I’m absolutely changing things far from the brand intentions.

Wharferdale diamonds though are an easy win. :) B&W has used caps exclusively as the distinguishing feature between some models. In these cases and upgrade may be ideal.

With some older speakers, made in the 1980s for instance, not only are you dealing with older parts but non-ideal impedance curves.  Infinity and Yamaha speakers, and Focal Profile (newer than that, still crap impedance).  Definitely cases where a complete re-think of the crossover can have positive effects. This last approach requires a more advanced hobbyist capable of doing a complete speaker analysis, not just part swapping.

However, I love DIY and the point about making your own is a really good one.  Plenty of fantastic sounding, high end kits out there. :)



Honestly wouldn't do this with any high end speaker, but if you are curious I highly encourage you to build your own speakers and play with parts.  That's relatively inexpensive, and you aren't destroying anything you want to sell later. :)

It's also a great deal of fun and frankly we need more builders in these forums to keep the disinformation at bay.




I apologize to the audiophile gods.   Nobody can know more than someone who has hung up a shingle and become an OEM.

You can make a high end speaker sound better with better capacitors and resistors, but you have to experiment with different brand caps and resistors, before you figure out what brand will sound better than the ones the speakers came with.

@invalid Look at my photo above and there are some very good suggestions.

While many upgrade the capacitors, and resistors aren’t expensive to upgrade, inductors are often neglected, that is, not upgraded to a level consistent with the capacitors, where most put their money. I went with hand wound beeswax foil inductors.

I kept all the same values as the OEM designer, who is excellent.


thanks for the feedback. I think it is interesting that an $11k speaker needs modification. 

@falmgren you really think they used the best crossover parts that the could have for $11k? Did they use all silver wire in them?  They may also use lower quality crossover parts because of availability.

@falmgren "needs modifications" is too strong, and you probably meant it that way.  But if an $11K speaker couldn't be improved, there would be no need for a $12K speaker, would there?

Crossovers are one of the areas where speaker manufacturers tend to save money.  Like I posted above, I am spending $2300+ on parts.   the improvements will be small.  They would be unnoticalbe if I was an average consumer with a relatively inexpensive but powerful amp driven by his computer and the onboard DAC.  Also, crossovers are invisible (except on high end speakers where they actually give you a great crossover, then sometimes they make them visible below plexiglass).  But if you want your $11K speaker to sound like a $50K speaker, ugrading he crossover will be necessary.  I guarantee that an $11k speaker doesn't use $2300 worth of parts in the crossover.

Most, or at least many, upgraders like me, do not feel the need to change the design of the crossover, just the quality of the parts.  I am using the exact same values that the OEM used, just MUCH MUCH higher quality components.  

Also, the wiring inside the speaker can usaualy be upgraded, I'm changing to Duelund Cotton oil insulated pure copper wire at least one gauge larger than the OEM used.

I know several people who have done this upgrade and I heard before-and-after on one of them.  Huge improvement to those of us who are dealing in portions of that last 2%.  Probably un-noticable to the average consumer.




"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."

The original designed may have wanted to save money on cheaper parts, and as you've seen above, some have designed their own speakers.

My 2 cents...

And that's about what it's worth...

Modifying crossovers.... What is your purpose of modding and upgrading audio gears? Trying to make the audio sound better? What is the best sound then? What is the final destination? Is it the original Music/Sound?

Watch below video. Is it your final destination? Or do you have more upgrade to do? "BORRESEN X3 with AAVIK + ANSUZ "

My final destination audio is same or better than this.

Many people devoted their life times to get the original Music/Sound in last 150 years and gone without seeing it. No one was close. Will your mod get you the better than above videos’ sounds? I think not.

After Xover mod, I bet the speaker will sound worse. Speaker company has the experience with their speakers. OP doesn’t. Replacing better parts is not the promise of improvement. I know I make the best sounding speakers.

People say the speaker makes the biggest difference. If those speakers work with bad broken signals, your hard speaker work is wasting. For the best sound in the future, make sure the source has the best signal.

The original music can happen only with best power cords and cables. I think power cord upgrade is more sound improvement and much easier than modding xover without the risk. PC upgrade guarantees the sound improvement. Or return it. Alex/Wavetouch


What a ridiculous collection of statements. I wouldn't buy your speakers even if they weren't overpriced.

Post removed 

The item (drivers, cabinets, materials, crossover) look well built. I am curious "a new entry-level speaker at an affordable price" if I should fetch a handfull of 100 dollar bills and go get myself a pair? What IS the 'entry level' price for the X3? 

Regarding modifying OEM parts/materials, in my case vintage (Infinity Quantum 2): still undecided between

"they know better than me what is good" (here: tiny thin cheap internal wiring) or "it can't truly be cost that they chose those cheapo wires so don't mess with it"


"it can't be good to chase the signal through those horrible wires"

I get the 'cost' part for mass produced speakers.

But the more the price of a speaker deviates from the cost based price function (the material cost of a $100,000 speaker is maybe 10% of the sales price, the rest is eaten up by profit, sales/marketing/demos, development, customer service/support/warranty), the lower is the motivation to use lesser parts for cost reasons. 


Hi @falmgren, It doesn’t look like the consensus here is that you should improve your speakers’ xover. As you are serious about this, please check @elliottbnewcombjr ’s post above.

Changing the xover components for more expensive parts (I don’t think anyone of us here has evidence of which would be the "better" parts for that specific speaker!) could change the sound -- not necessarily better, but different.


It’s reversible, so go ahead, but stick to using exactly the same spec components. Someone above recommended Mundorfs and I too have had great experiences with them (the oil variant)



That is not a high tech crossover, not many parts IF you must, why not build a complete alternate crossover, then A/B OEM to Upgrade?

You could also leave one as OEM, and 'upgrade' a few parts the the other's factory board. Listen in mono/mess with balance, find a track with a lot going on in L or R track, evaluate one at a time for differences. Proceed or undo as you and/or your friend's ears tell you which is Preferred.

Clearly there are a few members here, a vocal minority that one person has called a "consensus" that think it is crazy to touch an OEM component and if God (the OEM) had intended you to have a better crossover, he would have given you one.

I’m fine with all those who don’t think it is a good idea. I think they are perhaps trying to come up with a reason why they shouldn’t do it. If it were to become the next hot mod, then they might be subconsciously forced to do it. Like cables.

As for doing A/B, installing a new crossover involves a lot of soldering of wires. In my case there are 6 seperate connections. Building an A/B would be a lot of work and expense. Those of us who have heard the mods, evaluated them technically, and understand what we are achieveing do not need to be convinced that it will sound better. Let me put it this way, there are likely components in the signal path in your speakers that you would shudder if they were in the signal path in your amp. Sand cast resistors that cost $1.99 apiece for one. Remember all those expensive bypass capacitors amp manufacturers use? Your speaker doesn’t have those, but mine will in a couple of weeks.

A friend has very similar speakers to mine.  Mine sounded slightly better until he upgraded crossovers.  Now every time I go to his house I'm reminded that I need to get my crossover upgrade done.

So don’t anybody feel you need to approve or disapprove of crossover modifications. Just like anything else in life, if it isn’t for you, don’t do it.


A quick story:

I was a audio dealer, speaker designer, and still currently involved in audio service and performance upgrades. Years ago I attended a convention and had a heart-to-heart with one of the most successful speaker manufactures of the past 30 years, He had recently introduced their new "flagship" model to rave reviews, and was an overnighht success. He was polite enough to give this guy some of his time, and we got deep into speaker "nurdystuff". After sharing my thoughts with him, he paused for a few seconds, looked me in the eyeballs and said: "I believe in all that.. I just don’t want to fight my engineers over it."

A few weeks later I decided to do a "what if?" experiment and did a "high end" top to bottom approach to the speaker, addressing all the things that stood out to me that could use a little "TLC." A month later, the regional manager for the company visited my store and I convinced him to spend some quality time with the OEM vs "modded" versions of the speaker. He sit there for a while listening, and I could tell the gears were churning. After the music stopped, I asked him how he liked them. His answer: "They sould better. Okay, what did you do?" My answer: "Everything your engineers told you wouldn’t make a difference." I think this may have perculated to the top.

I agree with @erik_squires that I wouldn’t mess with a high end speaker -- UNLESS they can be reverted to origninal condition. a) you might not like the changes, b) it may effect the resale value, and c) you might have just voided whatever remains of the factory warranty (on the raw drivers).

OEMs choose crossover designs based on a number of factors. Cost, manufacturing efficiencies, ease of service in the field, etc. But, there also has to be "buy in" to the design and components by all iinfluencers of the speaker design/manufacturing process. This is where philosophies (sonics, sonics ,engineering, financial, etc) enter in and present a very complex situation.

I have a very simple philosophy as I approach speaker "mods". Get things out of the way that make the speakers sound worse. These are usually not hard to find in speakers under $25k.

A quick note on "better" parts. If the values of the replacement parts are the same as original, the measured frequency response should be within 1db (non detectable) of the original. However, when the music starts playing, things become different in a hurry -- in a good way. Dynamic compresion is one of those stock OEM attributes that doesn’t sound "wrong" when you hear it. Until you realize how much headroom was compromised and micodynamics were squashed when the speaker is upgraded by better internals. This includes modern AND vintage designs.

Just my 2 sense.

My cautionary tale is to be careful in doing too much.  Tweeter and mid-cap upgrades are simple and easy. 

If you have a 1980's - 1990's vintage speaker though, it's worth doing a complete analysis before doing much work.  The issue is the tools and effort it took to get a good crossover back then to work across both frequency and impedance.  There's plenty of examples of speakers in this vintage that need different crossover designs. 

Be extremely careful replacing caps that go to ground, their effects on the impedance curve is unexpected, so measure and compensate for ESR changes. 





Thanks everyone for this very interesting and informative discussion. Let’s close this out. 



This used to be a VERY sore point for me. I got so tired of seeing SO Called High End Brand Names using something similar to Cat5 wire and a single off the shelf Radio Shack quality capacitor inside. I sincerely hope that this is a thing of the past. I might say that I do believe that most of the really quality speaker manufacturers have real science backing them up when they design their crossovers. I still try to have faith in the educated human mind.
I must remind the folks that there are so many components to chose from and different ideas behind how they go about creating a particular crossover. A Particular driver may have some inherent oddity that requires something that you are not aware of and can’t predict.
Also lets just look at one component, the capacitor. And even at that, One Brand, MUNDORF. They make so many different caps for any given value that it would be insurmountable for the average user to pick one and say that just because it is a Mundorf; it will give my speaker a better sound. You might hit on the right one but if you miss yo just wasted a bunch of spare change and time. and at the same time probably gained a slanted opinion of Mundorf when they really don’t disserve it.
Looking at Inductors, I would love to brag about continuous ribbon wound inductors over wire wound inductors but even then this could blow up in my fact just because I don’t know something about the coil in the speaker’s driver that would necessitate the wire wound over the ribbon wound.
And just to show you that I can screw up a speaker as well as the next guy. I took one of my own designs where I originally used Chartreuse caps in and always liked them, but thought I could do better so I spent a couple hundred dollars on some Mundorf caps. I have regretted that decision every day since.

I'm a big believer in the effect of using quality components in the crossover. I've done a modest amount of experimentation and have found that high quality parts can make a significant effect on tonal richness, dynamics, microdetails, and soundstage. 

Besides the obvious issues of resale value, warranty, etc., there are a few things to keep in mind:

Esoteric components, particularly capacitors, can add a tonal flavor that is different than the original design. This might be preferred by the listener or might not be, so just because a component is well regarded and much more expensive than the original part, it doesn't necessarily mean that it will be an improvement since we all have different preferences. 

Many of the higher quality parts are bigger (sometimes considerably so) than the original parts. IT may be challenging to actually get the new parts to fit in your speaker. I use some capacitors in my speakers that are 50% bigger than a 12oz can. 

Some of these parts, particularly esoteric film capacitors, can take hundreds of hours to "break in". During this time, the sound can change considerably - sometimes for the better and sometimes for the worse. So you can't really make a judgement when you first install the parts.

A classic example of the sanity of a) knowing the relative quality of your speaker’s crossovers and b) improving them if their quality is not to the level that you would like is the B&W Matrix 801 Series 2 speaker. Although widely regarded as one of the finest speakers that existed at the time of it’s introduction in 1995, it’s crossover was highly compromised due to the space limitations of the underside of the bass cabinet where it was placed in the interest of the speaker being highly moveable for it’s anticipated, and actual, use in recording studios...famously at Abbey Road Studios.

George Short, the brilliant speaker designer and founder of North Creek Audio stated that this speaker "...has some of the lowest distortion, inherently linear drivers of any speaker ever produced in one of the most acoustically inert cabinets of any speaker ever produced, but some of the worst specified crossovers of any high end speaker ever produced." This fact made his crossovers for said speakers extremely popular for at least two decades before he closed his business several years ago.

Suffice it to say, anyone with one of these speakers systems with Mr. Short’s crossovers has left the speaker consumer market.

There seems to be a lot of advice from people who have little to zero experience with XOs and even display resentment that somebody should have the temerity to suggest they could improve on what the OEM did.

The idea that if better parts were needed then the designer would have used them, is the result of not properly thinking things through and finding comfort in the dubious knowledge that their speaker is the best it can be. Really? There is very little that can't be improved with knowledge and some cash!

Caps are, for some strange reason, thought by most to be where the performance difference occurs so I will mention them in my example, but truth is all the components will have a sound and contribute to the end result.

OK, lets take a manufacturer who intends to produce 500 pairs of a certain speaker, and lets take the series cap for the tweeter. A cap in this position that will do the job can be found for $1 or less and will provide an acceptable frequency response.  The owner of a pair of these hypothetical speakers could replace cheapo cap with a $20 cap of identical value, which will provide the same identical frequency response as the cheap cap, and hear a nice improvement. So for $40 he could enjoy an upgrade on both speakers about equal to a $200 interconnect. (I'm generalising here)  

So why you ask, doesn't the manufacturer do this? Think about the cost!

By just looking at the tweeter caps and nothing else he would have to outlay $20 x 1000 = $20000

Everything matters in audio and in a XO which is widely accepted as the heart of a speaker it matters lots. For those that ask: how can a cap or whatever improve the sound, the answer is, it can't. What we are trying to do here is do the least damage to the signal.


@carlsbad2, nice looking XO you put together, congratulations. Are those Path resistors you have there and did you compare with any others? There is also what appears to be maybe a Mundorf resistor mounted on a heatsink. If so I think it is a Vishay device and adopted by Mundorf. I found the same thing under the brand Powertron and is cheaper. I find it clean, very dynamic and open and use it always with it's heatsink to avoid thermal compression. Also are those 2 caps next to the low frequency inductor Duelund bypass caps?

Regarding your choice of Duelund in cotton for internal wiring may I suggest you consider solid OCC copper in PTFE insulation instead. It's more expensive but in keeping with the other components you have in the XO. I normally remove any push on connectors and solder, vastly and consistently better. Solid core wire needs to be anchored close to the terminal to prevent fatigue. Do not twist + and - just keep about 1" spacing between. To take it up a level avoid using the speaker terminals as a connection. I do this on my speakers' and amplifier terminals. I bring the wires from XO outside the box and terminate with pure copper FUREZ spades. I use identical spades on the speaker cables also terminated with FUREZ spades and place them back to back into the terminals that now merely act as a clamp. Ideally removing those huge lumps of dubious quality binding posts, finding that a non-metallic way of clamping is better still.

Next step would be to have the XOs outside the box.

The best crossover is no crossover. Just listen to a good full range driver in a well designed horn cabinet. Why distort the signal through all that mumbo jumbo of wires and circuits?

"Why distort the signal through all that mumbo jumbo of wires and circuits?"


Why? Because full range drivers have their own shortcomings. Some people aren't bothered by them, others are. 

There is no perfect loudspeaker. In this instance you gotta decide if you want purity and soundstage or dynamics. 

@lemonhaze Good eye identifying the components.  Indeed those are Duelund bypass capacitors.  They are actually in the midrange circuits.  Didn't feel a bypass was necessary for the low frequencies.  The Path resistors are proven by friends that have done this mod so I'm not anticipating trying others.  The resistor in the heat sink is a 30W powertron. This is indeed the low frequency circuit.  I"ve had good luck with the duelund wire and have bought enough of it to rewire the speaker with it.  

Indeed, this is going to be an externnal crossover.  I started trying to put it back inside but there just isn't enough room.  I was going to have to put it on 4 boards mounted various places around the inside of the box.  So this panel that I have everything mounted on is about 12x12" and I'll be building a polished and oiled walnut box for it to go into.  I think I'll put a plexiglass top on it.

There currently are no push on connectors in the speaker.  Eveything is getting soldered up with Mundorf silver/gold solder.

thanks for the suggestions.


@boxertwin12  Indeed full range drivers have their fans and I'm glad you enjoy them.  I prefer to go the other way.  thanks.  Jerry

3 things...

  1. There once was a speaker designer who claimed changing the quality of parts in a crossover (while maintaining the same circuit design) changed the sound of the speaker. Many disbelieved. So, he installed an upgraded crossover in a set of 2-way speakers w/ an A/B switch, and graciously sent them to nonbelievers to experience first-hand, in their own listening space, with their own equipment. If I recall the results of the experiment correctly, the ability to distinguish "Crossover A" from "Crossover B" was unanimous, and the preference was for the crossover with "better" parts. If the additional expense is "worth it" is always a source of debate.
  2. I believe if crossovers were externally mounted (and on display like audio jewelry) the quality of the parts would increase dramatically. And, yes, cost would increase dramatically, too.
  3. There is no "best crossover" (including the "no crossover" option). There are only trade-offs.

@nrenter Good post.  BTW, the new crossovers I'm making are going to be external with a plexiglass top.  

As for "is it worth it?   I'll have about $3k in this upgrade by the time I'm done.  I don't expect it to be a religious experience.   But I think I'll get more out of it than I got out of my $4k streamer upgrade.  Probably less than I got out of my $12K DAC upgrade.  Definitely I've spent $3k at times on amps that turned out not to be an upgrade.


Several years ago, when I had an obsession with vintage Pioneer equipment, I stumbled onto a set of Pioneer HPM-200 speakers (in pretty good condition) and wanted to see how much performance I would squeeze out of them. I commissioned a gentleman to reverse-engineer the crossover circuit and rebuild it with premium parts. The sonic results were amazing (and the measured performance was impressive, particularly given this is a complicated speaker designed in the 70’s). My whole restoration is documented over at Combined with a minty (and restored) Pioneer SX-1250, a Realistic LAB-500 turntable, and a TEAC R2R, those speakers round out a very cool vintage system. Soon, I’ll want to part with it all, and I’ll probably never get out of it what I put into it,  but the parts upgrades did make a difference. 


Jerry ,  Your crossover is beautiful and your intent on mounting it externally should provide and extra level of improvement that I can't figure out why we aren't seeing speaker manufacturers doing it . 

I wish that the crossovers in my speakers were as simply designed as yours , the woofer board alone have more components than your entire crossover board .  I am just one capacitor away on the mid range from finishing my crossover upgrades. It's been a lot of work that few can or are willing to undertake but I'll say it been well worth the expense and effort with more than a 2% increase in sound quality , after all each of our components are built to meet a price point .  




@vair68robert My internal crossovers are on 2 boards and to replace them interally with bigger components would have taken at least 3 boards.  I appreciate the simplicity but am no expert at designing crossovers.  I'm going with the same values as the original design.  Sounds like you are too. Enjoy.  


@carlsbad2 - your crossovers look very nice - much neater than mine. I was pretty tight on space with the caps I ended up using. 

+1 @erik_squires   I've "crossover component upgraded" a dozen pairs of decent mid-fi speakers with terrific success, however, these all had 20 cent caps in the crossover.  I never varied from stated values.  

Always upgraded the wire also.  For $50 total it was amazing how much more performance could be squeezed out of the current design with better parts.

The Borresens need be carefully assessed at that level before 'Frankensteining'.  A slip of the scalpel and you've a doorstop.

@jaytor I was headed that way (internal) but I went with Jantzen foil inductors and I finally gave up trying to make everything fit.  I even had one built and disassembled it last night.  Good luck with your upgrade. 


@carlsbad2 - I've been using these crossovers in my dipole planar-magnetic line arrays since November. They took a few months to fully break in, but are now sounding fabulous. 

It's not wrong to want to eek out more performance from current or new speakers. Adding components of higher quality may make no noticeable difference or maybe it will be fabulous. If you are so inclined you might actually decide that your improvements may breathe new life into your already trusted system to the point that you don't feel the need to make a major purchase. If I'm thinking of some new speakers why would I not at least consider upgrading what I already have. To me it makes fiscal sence. I will also learn another how to. For me this should at least be considered. 

While the question is " Modifying Crossovers "  the reality is that we are  "upgrading" our crossovers .  I have even stayed with the same manufacturer for the film capacitors , as to not stray far from the original " house sound " of the speakers . For me the resistors were the surprise performance improvement .