Model 19 crossovers under way

[BillWojo]

Since it's a royal PIA to post pics here I posted them along with a running progress report over on AK.
Z19 Crossover | Audiokarma Home Audio Stereo Discussion Forums

It starts on page 17 at post number 338

I have to give credit to our member Petro for the idea to build this turret style. We have been going back and forth with designs over the last few weeks for the final layout.
The last parts that will be added is the caps. This way they come off easy and I can remove them and try other types of caps very easily. All the wiring will be below the caps, secured by nuts so when the caps are removed nothing else is disturbed. Also allows easy testing of bypass caps.
I'll post more pics over there as I progress.

BillWojo

[xinu]

Looks like your off to a good start over there. Will be interested to see your progress and when you hear the results.

I'm still waiting for the remaining parts to arrive so I can complete the layout of the 878B Santiago crossovers I'm building. Hope it's worth the effort. I'll try to post some pics on a related thread.

[Elitopus1]

Bill, I checked out your pics on AK. Looks like a great idea the way you are mounting the components. Once you figure out what caps you like you could always permanently solder everything in place. I'll be following your progress

[BillWojo]

With brass screws and nuts and tinned copper terminals I think they will be fine. Been working fine in heavy industrial applications for a century now.
For the crossover wiring I'm using 12GA solid for the LF side and 14GA solid for the HF side. A nod to our own MrLowOhms, he would like that. And NO, not going to run double wires for all my connections. LOL
All wires are soldered into the terminal connections, I was originally going to use my Amphenol crimpers for a cold weld joint but the use of a lot of flag terminals nixed that idea. Not spending 500 bucks or more for one specialty crimping tool.
It's been a 3D puzzle getting all the wires into place neatly but I'm down to just a few left. After that I need to add the inductors and the caps.
I'll temporarily mount the L-pads to some kind of bracket and just put the whole mess on top of my AS101's to play around with them.
Hoping to find some time this weekend to work on it some more.

BillWojo

[Petro]

Bill Looks great!!! I'm right behind you also. Now you got me thinking of solid wire
Great job so far!!!

[xinu]

Hi Bill - making good headway by the looks of it.

I peeked at the Z19 network related to your posts over on AK. Lots of stuff going on the HF side of the x-over. Much more complex than the rather simple HF side of the crossover I?m wiring up for my Santiagos.

Do you have a link you can point me at for a basic description on what the Z19 HF circuit is doing? Is LP1 some form of notch filter and LP2 looks to be wired up to do more than just wide attenuation?

Thanks,

Greg

[BillWojo]

From what I understand one pot attenuates the mid range to flatten out the curve and the other pot attenuates the hi frequency.
I posted a pic with all the wiring complete, just have to add caps and inductors.

BillWojo

[LowOhms]

With brass screws and nuts and tinned copper terminals I think they will be fine. Been working fine in heavy industrial applications for a century now.
For the crossover wiring I'm using 12GA solid for the LF side and 14GA solid for the HF side. A nod to our own MrLowOhms, he would like that. And NO, not going to run double wires for all my connections. LOL
All wires are soldered into the terminal connections, I was originally going to use my Amphenol crimpers for a cold weld joint but the use of a lot of flag terminals nixed that idea. Not spending 500 bucks or more for one specialty crimping tool.
It's been a 3D puzzle getting all the wires into place neatly but I'm down to just a few left. After that I need to add the inductors and the caps.
I'll temporarily mount the L-pads to some kind of bracket and just put the whole mess on top of my AS101's to play around with them.
Hoping to find some time this weekend to work on it some more.

BillWojo

Hi Bill,

I have not been able to call up your photos, but I read above my name being mentioned.

I would suggest you do NOT use solid wire, 12 AWG and 14 AWG.

Perhaps I can help you.

The 12 and 14 AWG wire, that we use these days is Mil Spec, copper multi-stranded, with a highest quality SILVER coating, on each strand, in a TEFLON jacket . Lovely to work with. The number is m22759/11 12 and m22759/11 14. Its the BEST bang-for-the dollar wiring I am aware of, and we have tried " cost no object wiring " like $18,000 a pair speaker cables", and been into audio wire with Bob Fulton, since 1978..

You can go on eBay and get some easily, but if you would like, contact me at [email protected] and I will immediately make available colors and lengths you need for the two crossovers ( ONLY), at my cost, typically $0.55 a foot for 12 AWG and $0.45. a foot for 14 AWG

Solid, in those gauges, is a NO NO. . If you have it in there, RIP it out, replace it with this.

I only have BLUE in 14 AWG. I have orange, yellow, and white in 12 AWG. I will be willing to supply you with just enough to do the two crossovers, and THAT is it !!

Do use the same wire-type, which YOU will have to source, on eBay, smartly - over time, (1) amp to crossover, and (2) crossover to driver terminals. It costs virtually " nothing " to make the runs Fulton lengths, 57 1/'8th inch, and or multiples or divisors of that length.

My FAVORITE crossover to driver configuration is two 12 AWG to EACH woofer polarity, 57 1/8th, ( which equals 9 AWG, delicious sounding ) and one 14 AWG ( better bandwidth ), 57 1/8th, to the compression driver, each polarity.

On the amp-to-speaker wiring, if its three Fulton lengths or less, use doubled-up and lightly twisted 12 AWG for each polarity. If over 14.28 feet, use three 12 AWG for each polarity. This Mil Spec wire is lovely to work with, and, as I said, the very highest performance-per-dollar, of ANYTHING "I" know of. Contact me by email, and / or we can exchange phone numbers, so its an easy and productive multi-dimensional interchange.

Regarding crossover caps, there is ONE brand, in two values, that I find is a MUST-have, if you want really great sound. Nothing in audio will compare to their performance, and, after A-Bing them against all I had, I feel its a waste of one's time, and life, NOT to include these in the ALTEC crossover, as part of a cap bundle.

Its the DynamiCap 4.0 "E" and / or their 10.0 "E", either value, but ONLY those values !! I modify their leads with M22759/11 12 and 14. Percy has these caps, and they are now about $65 and maybe $87 each, but - they are easily worth $200 each.

AS I say, NOTHING compares to these two, in THOSE values, in ALL of audio. It does WONDERS for my ALTEC speaker. If you want to hear an ALTEC as good as possible, either of these values and brand are MUST-haves !!

I use four 4.0s for my stereo DIY VOTT A7-800 crossovers. WOW !!

( Actually, I use FIVE caps in each cap position, as a "bundle" to make up the "C" in each position. No one cap does it all, optimally. ) Those DynamiCap 4.0s, I LOVE having in my audio system. In my amps too.

Contact me. Best wishes.

Jeff Medwin......Low Ohms.

[BillWojo]

Hi Jeff, thanks for your offer but what I'm using is already way over kill for this application. 12Ga solid copper is rated at 41A in a chassis, has a loss of only 5.2 ohms/Km. 14Ga solid copper is rated at 32A in a chassis, has a loss of 8.3 ohms/Km.
I'm pushing these speakers with a set of Mac MC40 mono blocks, probably using no more than a few watts. Insulation rating is 600V so the 12Ga wire is capable of delivering 24,600 Watts, the 14Ga wire is capable of delivering 19,200 Watts.
Even if my calculations are off by a wide margin, I have designed in a ton of over kill.
Look at the stock Altec crossover wiring for comparison, nobody has ever claimed that the stock wiring is deficient. Worn out caps, yes, but not the wiring.

BillWojo

[LowOhms]

Hi Jeff, thanks for your offer but what I'm using is already way over kill for this application. 12Ga solid copper is rated at 41A in a chassis, has a loss of only 5.2 ohms/Km. 14Ga solid copper is rated at 32A in a chassis, has a loss of 8.3 ohms/Km.
I'm pushing these speakers with a set of Mac MC40 mono blocks, probably using no more than a few watts. Insulation rating is 600V so the 12Ga wire is capable of delivering 24,600 Watts, the 14Ga wire is capable of delivering 19,200 Watts.
Even if my calculations are off by a wide margin, I have designed in a ton of over kill.
Look at the stock Altec crossover wiring for comparison, nobody has ever claimed that the stock wiring is deficient. Worn out caps, yes, but not the wiring.

BillWojo

Bill, With TONS of respect, you are looking "one-sided" at the wrong data.

Its not singularly copper loss at all - that is important - but rather, how well does the wire play the musical experience, the transfer of energy, in all frequencies, linearly.

Solid 12 and 14 won't do at all.

Also, every potentiometer you add to a crossover becomes a sad source of BAD BAD sonics!!!

A good crossover design will have NO variable resistors what so ever. Just fixed resistors, soldered in place. That is SO audiably superior Bill !! Let me repeat that:

A good crossover design will have NO variable resistors what so ever. Just fixed resistors, soldered in place.

On a pot, you are running the entire audio signal through a TINY element between the wiper arm and the circular resistive element. It acts like a diode, and a poor contact, simultaneously.

For 2016, I ran an Ohmite F-Series 25 watt 6 ohm pot to pad-down each of my 802s . ( A 12 dB per octave A7-800 DIY crossover, at 16 Ohms ) .

I replaced my 6 Ohm pot, in December 2016, with TWO Ohmite F Series 6 Ohm pots, wired in parallel. I thus had two wiper arms and two resistive elements, and two times the wiper-to-element contact surface area.

Hey, that was MUCH better sounding. Never a single pot again !!

But then, I measured the pad down, less than one ohm, so I took a huge ( looks like 40 Watt ) wirewound resistor, from my Bob Fulton speaker days, and soldered it in place as the pad down.

AT LAST, the top end on that speaker side sounded QUIET, and lovely to boot. Bliss to my ears.

But the other speaker in the stereo pair was in an open archway, had no corner for woofer / room augmentaion, and required 3.2 ohms of pad down. NOT good !! I really wanted both crossovers to only use fixed resistors, and that these fixed resistors be chosen as a good compromise value, the same value, left to right.

My very exepreinced audio friend told me what to do. ( my friiend was in the movie theater business all his life, has owned more VOTTs than you and I have fingers and toes ). He said :

Place the speakers in the room so that BOTH VOTTS had corners to play in, pick a single good resistive pad-down Ohmic value, and SOLDER IN A HIGH QUALITY RESISTOR into both 'de 802s' crossovers. He said, " Make fine speaker adjustments by incremental speaker positioning, to get the final precise play back acoustic you wanted. "

He KNEW what to do !!

Guess what I did this week, Bill. I moved all my LPs, from one wall to another...well, all my in-the-room LPs,.... ( I own over 10,000 total. ) and I moved my VOTTS so they BOTH had corners behind them.

Realize, I use 290 pounds of patio paving stones on each stock 825 VOTT enclosure, so moving them for an older guy like me is not an easy thing to do. Coming up next, I will determine the Ohmic value to be used in both speakers, a same value, and solder-in the riew wirewounds, and do my fine-tune positioning.

I do know this, from recent work and listening, a single wiper arm / resistive element interface degrades the listening experience to a level unacceptable to me, and likely, to anyone else seeking high quality fidelity. Now YOU all know !!

the question I have is " Who is willing to experiment and follow ". Oh well, I am doing it for me, just sharing herein. Do as you like. The wire offer is open Bill.

Jeff Medwin