Crossover assembly 101

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Danny Richie

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Re: Crossover assembly 101
« Reply #240 on: 21 Sep 2020, 12:32 pm »
First of all, if you are going to post pictures please hide or conceal the values used.

Danny, a friend of mine who knows a lot more about building circuits than I do had the following comments. Could you please comment and confirm whether I need to address any of his comments. (1) Resistors get hot...so not a good idea to have them next to to the caps. Recommend you keep them off the board for airflow and away from other components and not have them held by zip ties, he is thinking they may generate 5W or so

They won't get hot enough to hurt anything.

 
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(2) To use sandpaper and strip the ends of the inductor till the copper shows. Thanks. (BTW, hearing you comment about how the bypass caps take things to the next level. I did go ahead and order them. Being a novice took me a while to find them on the web at sonic craft and order them.

We stock them and can add them in to your order.

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Recommend you adding them as another orderable option on your site.) Given all the hours I have put into building the kit I am perfectly willing to spend another eighty dollars on the cap if that will take things to another level.) My son and I can't wait to complete the project.

We'll have that option up on the new website.

corndog71

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Re: Crossover assembly 101
« Reply #241 on: 21 Sep 2020, 10:39 pm »
Danny,
You may want to make a sticky post regarding posting crossover pics and part values.

MattSelinger

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Re: Crossover assembly 101
« Reply #242 on: 16 Nov 2020, 01:02 am »
Regarding the bypass caps...  I recently called up Danny and ordered the Miflex bypass caps to add to my X-LS Encores.  I had included all the upgrades but did not know about these when I made the order.  So this was a retrofit and I had to take apart my encores.  Danny suggested I might have enough slack to add the caps without having to unsolder the leads to the tube connectors to pull the crossover all the way out.  He suggested just sliding it out as far as I could and add the caps.  Danny was right.  Just enough room to get the crossover half way out of the woofer hole.  It was a little dicey to twist wires and solder one of the connections.  Took about 2 hours to make the modification altogether.  Thanks Danny for the guidance.

I do have a question - what is the bypass cap doing?  I can hear the difference.  Greater clarity/texture... sounds even more "real."  I would love to understand what is occurring in the crossover when you add this bypass or additional pathway for the signal.

Hobbsmeerkat

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Re: Crossover assembly 101
« Reply #243 on: 16 Nov 2020, 02:02 am »
As its been explained to me, bypass caps allow the highest frequencies to pass more freely & cleanly thru the crossover to the tweeter, with as little loss of quality as possible, allowing for better clarity and detail.
Hopefully that helps explain it a little better! :thumb:

Early B.

Re: Crossover assembly 101
« Reply #244 on: 16 Nov 2020, 04:51 am »
As its been explained to me, bypass caps allow the highest frequencies to pass more freely & cleanly thru the crossover to the tweeter, with as little loss of quality as possible, allowing for better clarity and detail.
Hopefully that helps explain it a little better! :thumb:

Huh?? So correct me if I'm not understanding you correctly -- the signal flows through the larger, lesser quality cap, but then it flows through a higher quality bypass cap that passes its sonic signature onward through the remainder of the signal path. And because the bypass cap is so small, it doesn't affect the crossover design.   

Hobbsmeerkat

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Re: Crossover assembly 101
« Reply #245 on: 16 Nov 2020, 11:55 am »
Huh?? So correct me if I'm not understanding you correctly -- the signal flows through the larger, lesser quality cap, but then it flows through a higher quality bypass cap that passes its sonic signature onward through the remainder of the signal path. And because the bypass cap is so small, it doesn't affect the crossover design.   

Close but not quite, the bypass cap is run in parallel with the larger primary capacitor, so the signal passes thru both caps simultaneously, but the bypass cap only passes the highest frequencies, while the main cap passes all frequency ranges for the tweeter.

You can have both cap & bypass be the same quality, but usually, high end copper caps get expensive the bigger they get. (They also are quite physically large as well) Like a single large copper capacitor in the tweeter circuit can easily cost $800+, for just one and still use another small copper bypass cap.. so high end bypass caps with a good quality Sonicap are often a compromise between cost/performance.

But you are correct that their size doesnt influence the overall crossover design.

Early B.

Re: Crossover assembly 101
« Reply #246 on: 16 Nov 2020, 02:46 pm »
Close but not quite, the bypass cap is run in parallel with the larger primary capacitor, so the signal passes thru both caps simultaneously, but the bypass cap only passes the highest frequencies, while the main cap passes all frequency ranges for the tweeter.

You can have both cap & bypass be the same quality,...

I'm still not 100% clear. A google search brings up a ton of explanations, but none of which I've read so far are particularly helpful. I have three questions:

1. If the bypass cap is passing only the highest frequencies, how does that improve the sound since the main cap is also passing the highest frequencies simultaneously? 
2. Bypass caps can go on the midrange, as well. What role is the bypass cap playing -- is it passing the highest frequencies within the midrange band?
3. What benefit is there to have a bypass cap of the same quality as the main cap?

Thanks.

 

Hobbsmeerkat

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Re: Crossover assembly 101
« Reply #247 on: 16 Nov 2020, 03:52 pm »
I'm still not 100% clear. A google search brings up a ton of explanations, but none of which I've read so far are particularly helpful. I have three questions:

1. If the bypass cap is passing only the highest frequencies, how does that improve the sound since the main cap is also passing the highest frequencies simultaneously? 
2. Bypass caps can go on the midrange, as well. What role is the bypass cap playing -- is it passing the highest frequencies within the midrange band?
3. What benefit is there to have a bypass cap of the same quality as the main cap?

Thanks.

1&2 share a similar reason. Smaller caps discharge more quickly than larger ones, allowing them to pass the highest frequencies more cleanly, where a large single cap will tend to "smear" those higher frequencies.
I believe for mid range circuits, it follows a similar principal, but the capacity is larger than those used on a tweeter circuit, (since both the top ranges are knocked out of the signal), allowing the upper-mid range to pass more cleanly in the same manner.

3. Cost ususally, but even if they're both ultra-high quality copper/waxpaper caps, the highest frequencies still benefit from a bypass cap thanks to their faster discharge rate.

Heres the one on my base XLS:


And the one on mikeeastman's NX Studio:


Both do the same thing but are totally different quality levels.

Early B.

Re: Crossover assembly 101
« Reply #248 on: 16 Nov 2020, 05:08 pm »
1&2 share a similar reason. Smaller caps discharge more quickly than larger ones, allowing them to pass the highest frequencies more cleanly, where a large single .

Here's where I'm confused -- if the smaller cap is discharging faster and more cleanly, the main cap is also discharging, but at a slower rate and not as clean, so you're still getting a smearing effect. Seems like the smaller cap would make it sound worse, not better.

I've used bypass caps in the past in both the tweeter and midrange circuits, and they've made a minor improvement, so I'm not "smearing" the use of bypass caps -- just trying to understand why they work.

   

Hobbsmeerkat

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Re: Crossover assembly 101
« Reply #249 on: 16 Nov 2020, 05:56 pm »
I'm not 100% on this so if someone can explain it better, by all means chime in.
To my understanding, the smaller cap is a path of lower resistance for the highest frequencies, which will pass through at a higher levels than they will thru the main cap. So while the "smeared" sound may still be occuring thru the main cap, its not going to be as noticable since most of that signal is coming thru the bypass connection, the smearing effect is greatly reduced.

The remaining signal is blocked out from the bypass cap, allowing the rest of the signal to pass thru the main cap unimpeded.

corndog71

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Re: Crossover assembly 101
« Reply #250 on: 16 Nov 2020, 08:14 pm »
I haven’t heard great explanations for this and yet I’ve definitely heard a positive difference from adding bypass caps.  I know a couple brands of caps that seem to roll off the higher frequencies but with a good bypass sound more balanced.  And even Sonicaps which don’t sound muted or muffled up top benefit from bypass caps. 

Danny Richie

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Re: Crossover assembly 101
« Reply #251 on: 16 Nov 2020, 09:05 pm »
Here's where I'm confused -- if the smaller cap is discharging faster and more cleanly, the main cap is also discharging, but at a slower rate and not as clean, so you're still getting a smearing effect. Seems like the smaller cap would make it sound worse, not better.

I've used bypass caps in the past in both the tweeter and midrange circuits, and they've made a minor improvement, so I'm not "smearing" the use of bypass caps -- just trying to understand why they work.

All caps store energy to some degree. The smaller they are the faster they discharge. So think of it as the smaller cap is shorting the larger one to discharge stored energy.

And when using caps of different values the discharge rate differences do cause a phase shift. So it is not good to use a 15uF cap and a 5uF cap to make a 20uF value. The phase shift can be in an audible range and cause the smearing effect.

However the bulk of the phase shift that the .1uF or smaller cap causes tends to be at or above 20kHz. So it is not really heard.

Lebo

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Re: Crossover assembly 101
« Reply #252 on: 20 Nov 2020, 04:10 am »
I just received my Encore X-CS and wanted to read this cross over sticky on Crossover assembly.  However, the pictures Danny attached are not downloading.  I get the framed picture of a blue question mark.  I am using a MacBook and Safari.  I made configuration changes to my browser based on others suggestions but I haven't had any luck.  Does anyone know another way to access the Crossover Assembly pics?  Thanks

Hobbsmeerkat

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Re: Crossover assembly 101
« Reply #253 on: 20 Nov 2020, 11:03 am »
I just received my Encore X-CS and wanted to read this cross over sticky on Crossover assembly.  However, the pictures Danny attached are not downloading.  I get the framed picture of a blue question mark.  I am using a MacBook and Safari.  I made configuration changes to my browser based on others suggestions but I haven't had any luck.  Does anyone know another way to access the Crossover Assembly pics?  Thanks

Its not you, it's been that way ever since Dannys old email server was taken offline to start setting up the new website. He's still working on getting those pictures back online for them to start appearing again.

Lebo

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Re: Crossover assembly 101
« Reply #254 on: 20 Nov 2020, 02:55 pm »
Thanks HobbsMerkat.  I can see pictures you and others have posted.  I will try and get the general idea based of other posts unless someone out there has a specific Encore X=CS out there they can send me.  I'm sure its simple to but everything is hard the you don't know how to do it.  As simple as the schematic for the crossover looks it is still Greek to me.  But I'll get it.  Thanks again. 

Hobbsmeerkat

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Re: Crossover assembly 101
« Reply #255 on: 20 Nov 2020, 03:38 pm »
Thanks HobbsMerkat.  I can see pictures you and others have posted.  I will try and get the general idea based of other posts unless someone out there has a specific Encore X=CS out there they can send me.  I'm sure its simple to but everything is hard the you don't know how to do it.  As simple as the schematic for the crossover looks it is still Greek to me.  But I'll get it.  Thanks again.

I believe the crossover on the X-CS is quite similar to the X-LS except for one less resistor on the Tweeter circuit. But should have the same woofer circuit.
But feel free to DM me if you have any specific questions!  :thumb: