WH6, crossover question

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SethRocksYou
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WH6, crossover question

#1 Post by SethRocksYou » Thu Nov 05, 2020 10:26 pm

Just got all my crossover components in from PE for a pair of WH6's. I went with the electrolytic cap for the low pass and poly cap for the tweeters, as the plans mention.

I'll be putting a DPDT switch in the cabs to switch between the 2 circuits in the 4 pole SpeakOn's and wondered if it might be a good idea to put a 200µf capacitor between the jack and the crossovers to minimize possible damage to the drivers if I accidentally run a subwoofer signal to it.

A 200µf poly cap is unreasonably expensive, but an electrolytic is only about $3.

I just did a little research on the difference between poly and electrolytic caps for crossover use and it looks like electrolytics are avoided for high frequency use for some reason that I don't quite understand yet. But, there was some mention of it possibly being okay to use the two in series.

Would adding a 200µf electrolytic capacitor in series between the jack and the crossovers create problems with the sound quality? Should/could I just put it inline on the positive lead before the woofer lowpass filter and wire the tweeter filter direct (not through the 200µf cap)?

Will this even do what I'm intending it to do? Is 200µf an appropriate value to use for the purpose? Is it even a good idea?

Thank you :thumbsup:
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Bill Fitzmaurice
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Re: WH6, crossover question

#2 Post by Bill Fitzmaurice » Thu Nov 05, 2020 10:37 pm

Don't run a subwoofer signal into it. You can never do that if you wire the subs to 1+ 1- and mains or wedges to 2+2-. Problem solved.
Polys are used for high frequency signal pass through because they have low ESR, equivalent series resistance. High ESR doesn't matter much on low pass shunts to ground, so electrolytics are OK there.

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Re: WH6, crossover question

#3 Post by SethRocksYou » Thu Nov 05, 2020 10:54 pm

Bill Fitzmaurice wrote:
Thu Nov 05, 2020 10:37 pm
Don't run a subwoofer signal into it. You can never do that if you wire the subs to 1+ 1- and mains or wedges to 2+2-. Problem solved.
Polys are used for high frequency signal pass through because they have low ESR, equivalent series resistance. High ESR doesn't matter much on low pass shunts to ground, so electrolytics are OK there.
Thank you Bill. That certainly sounds like it would be the best practice.

All my mains and subs are wired as you suggest. However, I'm making my monitors with a switch, so I can get 2 mixes per cable run to limit the number of runs/wires. I'm trying to avoid damage if the wedge accidentally gets plugged into a main/sub lead, which is unlikely... but would still like to add the safeguard if it's a viable solution.

Is adding the capacitor in series (not a shunt to ground) before the inductor on the low pass filter a bad idea, due to ESR? Or, would it be okay (and work as I intend)?
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Re: WH6, crossover question

#4 Post by Grant Bunter » Fri Nov 06, 2020 4:13 am

A capacitor in series to the filters after the input jack/speakon becomes the simplest form of a high pass, and maybe that's what you're after.

I don't understand why you need a switch.
Mark the monitors that run off 1+ and -, or 2+ and -, as such on the speakon panel plate of each monitor, or, if not using a plate, just mark the mons near the input 1 or 2. Wire them appropriately.
When setting up, place them appropriately.
When you set up, you can still use any 4 core cable with NL4's wherever you like, but only those monitors plugged into 1+ and - will work on that amp output, and 2+ and 2- on the other (based on a break out panel from your amp rack!).

While that is a little contrary to Bill's suggestion above, ordinarily I set up everything I own by myself, so it doesn't matter, as long as I know what I've done (and I do). However, sometimes you get help, wanted or other wise, and, to me, it makes it much simpler to be able to say "yep, if that lead's long enough, plug it in there and there, daisy chain them like this", and it's all good (I always check anyway).

I always set up FOH first, and monitors last (actually lighting is last, but that's not audio lol).
That helps decrease screw ups as well...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Bill Fitzmaurice
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Re: WH6, crossover question

#5 Post by Bill Fitzmaurice » Fri Nov 06, 2020 8:59 am

SethRocksYou wrote:
Thu Nov 05, 2020 10:54 pm
I'm trying to avoid damage if the wedge accidentally gets plugged into a main/sub lead
Color code the connectors.

Bruce Weldy
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Re: WH6, crossover question

#6 Post by Bruce Weldy » Fri Nov 06, 2020 10:08 am

Is this really a problem? If you use a labeled rack panel for all connections, it would be pretty hard to accidentally hook it up wrong. Now, if you are fishing around in the back of a rack to plug directly into and amp - then that leads to the possibility of making a mistake.

All of my cables are the same and every box uses 1+/1-. Plus, I tend to have the master volume on every monitor send pulled back and bring them up slowly for sound check. That way even is something is wired wrong - you'll know before you fry something.

You can't protect against every little incident of dumbassery (coined by my friend Earl - RIP), but if you use a rack panel, labels, and are careful - you should never blow anything up.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Re: WH6, crossover question

#7 Post by SethRocksYou » Fri Nov 06, 2020 11:38 am

Bill Fitzmaurice wrote:
Fri Nov 06, 2020 8:59 am
SethRocksYou wrote:
Thu Nov 05, 2020 10:54 pm
I'm trying to avoid damage if the wedge accidentally gets plugged into a main/sub lead
Color code the connectors.
I'd still like to add a safeguard if it's a viable solution.

Is adding the capacitor in series (not a shunt to ground) before the inductor on the low pass filter a bad idea, due to ESR? Or, would it be okay (and work as I intend)?
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

SethRocksYou
Posts: 1184
Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
Contact:

Re: WH6, crossover question

#8 Post by SethRocksYou » Fri Nov 06, 2020 11:46 am

Grant Bunter wrote:
Fri Nov 06, 2020 4:13 am
A capacitor in series to the filters after the input jack/speakon becomes the simplest form of a high pass, and maybe that's what you're after.

I don't understand why you need a switch.
Mark the monitors that run off 1+ and -, or 2+ and -, as such on the speakon panel plate of each monitor, or, if not using a plate, just mark the mons near the input 1 or 2. Wire them appropriately.
When setting up, place them appropriately.
When you set up, you can still use any 4 core cable with NL4's wherever you like, but only those monitors plugged into 1+ and - will work on that amp output, and 2+ and 2- on the other (based on a break out panel from your amp rack!).

While that is a little contrary to Bill's suggestion above, ordinarily I set up everything I own by myself, so it doesn't matter, as long as I know what I've done (and I do). However, sometimes you get help, wanted or other wise, and, to me, it makes it much simpler to be able to say "yep, if that lead's long enough, plug it in there and there, daisy chain them like this", and it's all good (I always check anyway).

I always set up FOH first, and monitors last (actually lighting is last, but that's not audio lol).
That helps decrease screw ups as well...
Thanks for addressing my question Grant and also sharing some smart options and safe setup practices. I suppose I don't NEED a switch. A switch does occur to me as a more versatile option though, not having to keep track of which wedge is wired which way.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Bill Fitzmaurice
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Joined: Tue May 02, 2006 5:59 pm

Re: WH6, crossover question

#9 Post by Bill Fitzmaurice » Fri Nov 06, 2020 11:46 am

The level of protection it adds is minimal, it's only a first order filter, and it will cause a loss of midrange response.

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Re: WH6, crossover question

#10 Post by SethRocksYou » Fri Nov 06, 2020 12:04 pm

Bruce Weldy wrote:
Fri Nov 06, 2020 10:08 am
Is this really a problem? If you use a labeled rack panel for all connections, it would be pretty hard to accidentally hook it up wrong. Now, if you are fishing around in the back of a rack to plug directly into and amp - then that leads to the possibility of making a mistake.

All of my cables are the same and every box uses 1+/1-. Plus, I tend to have the master volume on every monitor send pulled back and bring them up slowly for sound check. That way even is something is wired wrong - you'll know before you fry something.

You can't protect against every little incident of dumbassery (coined by my friend Earl - RIP), but if you use a rack panel, labels, and are careful - you should never blow anything up.
It's not a problem and I don't foresee it being a problem, but it's still a possible mistake. If not on the hard wired end, on the DSP end. I've made similar mistakes before, adjusting one thing in the DSP, that I thought was another (similar to making adjustments to an Aux Bus when I intend to be on the Main Bus). I don't intend or expect to make that sort of mistake. I don't intend or expect to ever hook it up to the wrong amplifier channel. However, shit happens, and the way I intend to have these wired leaves that door open. The best solution would be to wire it as Bill suggested, but short of that, all we/I can do is preventative measures. If I can put a reasonable safeguard against my own dumbassary (I'm certainly not immune) at a reasonable cost, it would seem silly not to. A $3 preventative measure vs. a probably never but still possible to blow $50 driver, I'll take the $3 insurance please.

But, the questions still remain... Is it an option? Will it have a detrimental effect on sound quality? Will it work for what I want it to do? Any reason not to add it in there?
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

SethRocksYou
Posts: 1184
Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
Contact:

Re: WH6, crossover question

#11 Post by SethRocksYou » Fri Nov 06, 2020 12:05 pm

Bill Fitzmaurice wrote:
Fri Nov 06, 2020 11:46 am
The level of protection it adds is minimal, it's only a first order filter, and it will cause a loss of midrange response.
Good info. Thank you Bill. That's the sort of information I was looking for. :thumbsup:
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Bruce Weldy
Posts: 7292
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: WH6, crossover question

#12 Post by Bruce Weldy » Fri Nov 06, 2020 2:47 pm

SethRocksYou wrote:
Fri Nov 06, 2020 12:04 pm
Bruce Weldy wrote:
Fri Nov 06, 2020 10:08 am
Is this really a problem? If you use a labeled rack panel for all connections, it would be pretty hard to accidentally hook it up wrong. Now, if you are fishing around in the back of a rack to plug directly into and amp - then that leads to the possibility of making a mistake.

All of my cables are the same and every box uses 1+/1-. Plus, I tend to have the master volume on every monitor send pulled back and bring them up slowly for sound check. That way even is something is wired wrong - you'll know before you fry something.

You can't protect against every little incident of dumbassery (coined by my friend Earl - RIP), but if you use a rack panel, labels, and are careful - you should never blow anything up.
It's not a problem and I don't foresee it being a problem, but it's still a possible mistake. If not on the hard wired end, on the DSP end. I've made similar mistakes before, adjusting one thing in the DSP, that I thought was another (similar to making adjustments to an Aux Bus when I intend to be on the Main Bus). I don't intend or expect to make that sort of mistake. I don't intend or expect to ever hook it up to the wrong amplifier channel. However, shit happens, and the way I intend to have these wired leaves that door open. The best solution would be to wire it as Bill suggested, but short of that, all we/I can do is preventative measures. If I can put a reasonable safeguard against my own dumbassary (I'm certainly not immune) at a reasonable cost, it would seem silly not to. A $3 preventative measure vs. a probably never but still possible to blow $50 driver, I'll take the $3 insurance please.

But, the questions still remain... Is it an option? Will it have a detrimental effect on sound quality? Will it work for what I want it to do? Any reason not to add it in there?
I hear ya' about being safe if it's a cheap option and works. I just don't think it's that big of a risk if you keep all your ducks in a row...... If you always soundcheck the system by bringing up the faders from zero - you'll catch those weird problems should they occur......before they can cause a problem.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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