Lets educate ESR on crossovers

Esreuter

Hi forum,

This audio rabbit hole runs deep.

what i am researching and pondering today is what does a cross over modification do?

i understand the basic concept of a crossover, making sure the right sound goes to the right speaker, but what happens when you change out those caps and other components?

you will have to educate me from laymans terms up into technical jargon.

IE, mods, make the range of a driver expand from x to x, they allow the driver to handle more power, add volume, clarity ect.

i will not be able to handle wiring specs, uber technical jargon with out an explanation and education.

that is why i am posting this though, I figured you folks who like to mod and have a geek meter on crossovers might enjoy the chance to explain things to a beginner.

for a point of reference, what would modded crossovers do for the monitor speakers, 70's 40's and cs2?

looking forward to learning from you all.

ESR:biggrin::biggrin:

Face

ESR? How ironic. :biggrin:

FTGV

Face wrote: »

ESR? How ironic. :biggrin:

Yarp.:biggrin:

mhardy6647

interestingly, "ESR" (equivalent series resistance) is a key property of capacitors!
Low ESR is good; modern film-type capacitors are much better than the cheap, cheesy nonpolarized electrolytic capacitors commonly used (even today) in many vintage loudspeakers.

Capacitors in a first order crossover act as "high-pass" filters. They allow high frequencies to pass through unhindered, but block low frequencies. In a first-order crossover, there is only one component (e.g., either a capacitor or an inductor). For the tweeter, a high-pass crossover is used (first order: one capacitor in series with one leg of the tweeter); for the woofer, a low-pass crossover is used (first order: one inductor, or "choke" used in series with one leg of the woofer).

The slope of a first-order crossover is 6 dB per octave. Thus, if a first-order tweeter crossover is used with a crossover frequency of, say, 2000 Hz, the signal reaching the tweeter would be attenuated by 6 dB at 1000 Hz, 12 dB at 500 Hz, 18 dB at 250 Hz, etc.

You may find many crossover calculators on-line; e.g., at www.partsexpress.com (which offers many resources for DIY speaker building and tweaking).

Take it away, next poster! :-)

jbooker82

I believe when they modd them they use the same values. So your not really chaging which sound goe to wich speaker. Although I am sure they can if you want too. I just sent my xo's off to have the componets reaplaced with higher quality componets of the same value.

Outfitter03

Esreuter wrote: »

Hi forum,

I understand the basic concept of a crossover, making sure the right sound goes to the right speaker, but what happens when you change out those caps and other components?

for a point of reference, what would modded crossovers do for the monitor speakers, 70's 40's and cs2?

ESR:biggrin::biggrin:

ESR I will give this a shot and I just started down this road one year ago so am pretty new to this also.

First off there are two types of crossovers, active and then passive. Active crossovers are powered electronic crossovers that are usually outside the speaker enclosure. Passive crossovers are the type you have been reading about getting modified on this forum.

The passive crossover job is to send the right Frequency of Audio Signal to the desired driver since the drivers are designed to handle different frequencies. The term crossover is referencing the frequency ranges and overlaps between these ranges. If a crossover is executed well for the specified drivers the output of the speaker will be a relatively straight line across the audible frequencies from the lowest bass that the speaker is able to produce to the highest high, which is usually well above most peoples hearing, particularly older adults.

The reason that people choose to modify crossovers is that companies are constrained to price points when producing speakers and most mass produced speakers have only adequate crossovers in order to keep costs down. The other reason is that many folks buy vintage gear that is still in excellent shape, but the crossover components, particularly electrolytic capacitors have a limited lifetime and as they age the electrolytic fluid dries up.

Most people who modify crossovers due so to improve the quality of the sound. There may be some increase in Sound Level but it is the quality of sound that improves. There is a whole language from the Rabbit Hole that describes these changes, but in summary it is better!

Most upgrades to crossovers include replacing the capacitors when they are nonpolar electrolytic with a quality poly film capacitor and the cheap sand cast resistors with a good non-inductive resistor such as one made by Mills or Mundorf.

Inductors may also be replaced especially if they are metal core such as in the Monitor Line for the Bass drivers. Many replace the binding posts and get the Brass out of their system and go with copper!

All of these changes really come down to budget, quality of speaker and retention. Would your Monitor speakers sound a lot better with tricked out crossovers? You bet. Does it make sense if you plan on flipping them in 6 months for a set of RTIAs, No. The upgrades don't have to be all or nothing either. You could decide to just change out the resistor and capacitor in the tweeter ckts for your 5 speakers. If you did this yourself it would cost about $125.00 in parts using Sonicaps and Mills resistors. Bang for the buck this would be a big tweak IMHO.

Outfitter03

ESR here is a quote from a different thread on a recent crossover upgrade. These are very nice speakers mind you, about $4,300 list when new.

george daniel wrote: »

Just an update; did a little listening today, caps seem to burning in nicely-- the highs are just out of this world good,,organic with sparkle is the best way that i can describe it.The soundstage is wide and deep,but the instruments seem better placed/defined--and the vocals are --well to me they are cleaer,focused,,for example acoustic folk such as Baez,S Mullins,, puts them right there in the room,,sittin' on a chair and playin'the guitar,,,one thing did pop up,,and that was a banjo--damn,, I could hear his fingers move up and down the strings,,and actually hear them being picked--just sounded so real. All for now--enough of my babble.

aboroth00

mhardy6647 wrote: »

interestingly, "ESR" (equivalent series resistance) is a key property of capacitors!
Low ESR is good; modern film-type capacitors are much better than the cheap, cheesy nonpolarized electrolytic capacitors commonly used (even today) in many vintage loudspeakers.
Take it away, next poster! :-)

Yeap, what most people do is replace all the older NPE (nonpolar electrolytic capacitors) which are usually the first to go as they oxidize over time and drift in their values. As a result people go to PP (polypropylene) caps which are very commonly used but larger in size which usually last for a lifetime without needing to be replaced. However NPE caps have a higher ESR so to not change the voicing of the speaker you'd need to add a resistor in series with the NPE cap you're replacing.

People say they hear a marked improvement over NPE caps over PP caps due to the decreased ESR causing the driver to play louder. But yes to OP's question, NPE's are cheap, and their values are easy to attain in a small size. However, they are not the best option for a XO. Replacing them will refresh your XO, bring all values into spec, as well as improving the sound from quality components. Resistors and inductors don't age the way caps do, so that's up to you if you decide to replace those.

aboroth00

Seeing you have Monitor speakers, my advice would be: Step up the speakers before you step up the XO. As soon as you feel you've plateaued in the respect that you cannot afford or want a higher priced speaker, then you can look into doing this mods. As someone pointed out up there, there is no reason to go refurbing the Xo if you're going to itch to upgrade your speaker.

Upgrading the XO if it is newer (less than 10 years old) is a marginal improvement compared to upgrading the speaker. A XO upgrade on the Monitor will not make it sound better than the RTi which uses better driver components. Updating a XO is to just make sure it has the purist possible path to the drivers.