How to design a high end crossover…

@teoaudio

My dream job, if I were still working, would be in high end audio. I truly understand what those people must go through, day after day now.

Create a crossover, love it until you hear George Harrison’s voice on All Things Must Pass, and get totally torqued at his transition between his normal singing voice and his upper range.

Go to this company’s website and look at their capacitor summation; it's brilliant and back breaking at the same time. They easily have to have $30k in caps to rate all of these at multiple mf's.

http://humblehomemadehifi.com

I'm stuck on this hobby for myself, gonna build my own speakers after I get my soon to come Omen's, but like my mentor said to me 45 years ago: You can learn this or become a doctor, it will take the same amount of time.

SMH

A: Yes it is, and no, it isn’t.

To "design" a crossover you need many more types of inductors and caps in a specific range to zero in on proving the math to be true by ear. It’s an art, after the science.

An example would be, a 1.2 mh inductor, air core and iron core in 18, 16, 14 and 12 gauge round wire, depending on frequency, and that equivalent in air core foil at their equal to determine which is correct. All have different sound.

Surprise, the more expensive ones sound better with better drivers… Iron core 15 gauge inductor, $10. Same value in foil 14 gauge, $38. It becomes obvious that material costs and quality sound reproduction are at odds with one and other from a product price point to consumer cost.

Same is true with caps, because they all have different attributes that has to be taken into consideration.

Then you have to understand that whe combining drivers, one XOver may be fine with a first order, but you may need a fourth to the next driver.

I thought it was all about math, but I was wrong. Even the wire interconnects color the crossover differently.
So, don’t go there as a critical endeavor unless you want to spend countless hours after the calculations to listening to music you know well over and over and over and over again, till it sounds natural. And a couple more overs after that.

I’d venture to say that someone that does this for a living on the high end easily has $20kmin stock parts that they know well to do this. Many good to better caps cost in excess of $300, and the quality of those is a total crap shoot when it comes to a final design.

You could easily wind up pairing a particular driver with a Bennic as a Mundorph EVO Silver Gold Oil. Look up the prices on those, it’s a revelation.

Opps. 1.2mh inductor, foil, Goertz, $43.

I don't doubt that. My studio stereo has one built into the amp, and it's just amazing. 
It's a Yamaha pro love audio unit, and fiddling that part of it from time to time, it just amazes me what digital can do, and I never thought I’d ever use that function, I just bought it to use as a cheap amp with a lot of watts.

@teo_audio

Yes, the highs and the mid’s are where you open your wallet and let the supplier take the money out, and thank God for that, since the higher in frequency you go, the smaller the mf needed. 

It's the difference between being familiar with what you’re hearing as opposed to seeing the musician perform in front of you in your minds eye. I simply can't believe that I am listening to the same speaker.

It all started when I stumble on DIY YT videos of people moding speakers for themselves or professionally by accident, and then start binge watching them. Danny at GR Research and a fellow named Joppe Peelen, as well as a bunch of others in the led me down the road to sin… 😂 


This is a random one from Joope: https://youtu.be/mcqVb08tgpo

The only speakers I own, or have owned, that I haven’t taken apart and modded are My KEF R's, just brilliant design and manufacturing quality that was beautiful to behold but I dare not fiddle with, lest I mess them up.

But yeah, I do take them all apart and check out pretty much everything just to see what makes them tick. That goes for just about any mechanical or electronic thing I own.

Oh heck yeah. Below is a link to a free online circuit calculator for a third order Butterworth, and this has no Zobel circuits or notch filters.  

Second link is to Humble Homemade HiFi for pictures of some of their more advanced x-overs.

https://www.omnicalculator.com/physics/crossover?c=USD&v=filter_order_type:0,additional_circuit:0,spread:8,type:3.000000000000000,filter_order_type_3_way:3.000000000000000,woofer_impedance:4!ohm,midrange_impedance:8!ohm,tweeter_impedance:6!ohm,crossover_freq_low:500!Hz

http://www.humblehomemadehifi.com/assembly.html

This photo shows one of their designs that incorporates cheap to expensive inductors for their specific attributes, and bottom drawer to top shelf caps.

It's a science that’s an art.

http://www.humblehomemadehifi.com/services/assembly_99.jpg

@wolfie62

Specific to bass reproduction.

I just received 5lbs on 12 ga inductor wire yesterday, 14, 16 etc coming. I have two lathes and am building a setup for the small one to do this on. This will help out with costs when you make 4th order, specific, to eliminate the need for a notch filter.

I’m also interested in trying absolutely everything at a particular number, I’ve chosen 1.2 mh, that I can use to determine pluses and minuses, the only ones I don’t have yet are a 10ga foil wound and a 12 ga Litz wire, but am ordering the Litz tomorrow, Solen, with my regular order from that supplier.

In a closed range measurement, 20-200 hz for extra precision, the foils are superior in my results. Not so much by manufacturer though, Dayton’s are not bad at less than ½ the price of some others.

All of this is not going to go to waste, after I scratch this itch, I’m using some existing good quality orphaned drivers for testing, as well as existing speakers I have, and will build some speakers out of the parts and sell them if I don’t replace my existing speakers with them.

This is where the DSP comes in handy, as great inductors for subs are ridiculously expensive, and I find them perfect for subs. I just wish more sub makers would consider that many people are buying dual subs now, and so make the upper range XO on the smaller ones at 200, so they can make an excellent combo with small bookshelf speakers, where the sub is used as part of the speaker stand.

Well, I didn't drink the whole bottle!

But yes, joking a bit.

First time in years I worked on a project and was surprised to look out the window and see the sun was rising.

Impressive.

Allow me to over explain.


The process, then you can judge me to your hearts content, based on the facts and without all of the speculation. And of course, I never retract anything, so I’ll slowly try a nudge this post back to discussing what is pertinent to the original intention of it, designing XO’s.

I’m retired, so I can spend 40 hours a week doing this, and still have time for other hobbies and working on my house. And if I stay up all night working on something? Just working while I’m in the groove, as opposed to in a rut, which you can do when you’re the boss.

Start at 4:30 in the afternoon, Check previous records and notes; work on the breadboard to build the XO prototype, hook up, run test sweeps, make changes and repeat till it looks better than the last best version from previous sessions, based on thinking about how to improve the design from the last session.

Make drink and move to listening chair, start playlist of selected speaker instrument tones and demo songs and listen for about 62 minutes, taking notes on good points and bad. Back to computer, log notes.

Repeat till 7am, clock out.
So yeah, I thought it was funny and posted it as half joke, half truth. Four listening sessions over that period of time? My God, could he walk back to the house?!
If you want to find fault, send me a note through Audiogon and I’ll be happy to provide you with all of my faults so you can really tee off on me with maximum effect in the future.

But if you can’t relax with a drink and listen to your stereo because you are alcohol intolerant, your religion forbids you from drinking you’re in AA, or your psych meds won’t let you have a drink, stop telling the world that on my post.

We should really be talking about trying to make the best XO that one can here, costs be damned, and time is not a major concern. Designing an XO like this, as Danny at GR R says:

People think I just sit down and punch in a few numbers to a computer program and assemble the parts, etc. That is nothing like what happens…

It >is< nothing like that; Danny knows what numbers to punch in after testing the drivers individually because the published specs are merely a guideline for selection, and are not dead on to the product that shows up at your doorstep. But he is also wise not to divulge too much because what goes on in his head is Intelectual Property, and important for his livelihood. 

I have one of his XO’s, and no matter how hard you try and get the specs out of me, that will never happen, because I was an artist, then a Senior Designer in ID, and I understand how important trade secrets, copyrights and patents are to making a living/profit. Someone uses one of my photographs or part of something I designed for profit? I’m going to sue them.

That is why I am amazed the Humble Home Made HiFi publishes photos of their XO builds, because of the IP they are disclosing.

Look at these photos, if you know what you are looking at, it’s all there. Of course you may have to put off that trip to Hawaii, for 4, to buy one, let alone with the accompanying speaker it’s in, but you can read the caps and inductors makers name, and what model from their selected line. Of course these are specific to a particular set of speakers they are designing for, and they don’t show those, but still…

http://www.humblehomemadehifi.com/services/assembly_116.jpg

Oh, one other thing, all of the Humble Home Made HiFi's that are round wire coils use Litz wire, out of all of their photos, only a couple are not.

@oldhvymech

You really do need a a soundproof supply room to break a lot of this stuff in, speakers to caps.

I'm speculating early on in my research on cables so far, without a complete understanding, so FWIW: I do think there is something to your ears becoming accustomed to a new component, so breaking them in; but I also think there is something to breaking something in like a speaker cable, from a physics stand point, and that could be something as simple as the cabling's jacket shrinking from mild heat and off gassing, changing the relationship of the conductors distance from one and other. 

I do not think, at this point, that the physical nature of the conductor changes after manufacturing changes, unless something like cryotreatment is applied, or the wires are annealed after the drawing of them, tempered or surface smoothing, or a combination of those, to make a superior cable. 
Caps? Yep, physical and chemical relationships are being ingrained in the parts memory, bringing out it's full character.

Inductors? See wire finishing.

I'm self taught, so don't have anything to relate from others who I've learned from except what I learn from my testing, and other people affecting those judgments by my studying their designs.

A cheep tip. Not on XO's but…

Want better results from standard SxS speaker cable? Mesure out length you need, adding a couple of feet. Place one end in a vice, one the other attach to an VS electric drill. Slowly twist the wire under tension till you get 6 twists for every foot, then anchor the drill with a weight. Set the twist with a high powered hair dryer, careful not to melt the wire, let cool. 
If it didn't keep the twists, it wasn’t heated enough, or you have a high temp jacket, and so have to add twists in the beginning knowing that the cable will relax.


Now you have much better speaker wire.

@douglas_schroeder

👍

Some people only post to prove how much they know. I'm conversational by nature, so like to post and reply that way.

Besides, I made headway the other night, and that's what truly matters, is t it?