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HPF/LPF on GK head?

estimated_eyes

estimated_eyes

May 12, 2013
189
189
#1
Adding overdrive into my chain (which is currently clean to amp) and want to make sure I maintain a solid FOH sound.

I started reading about LPF’s for help with a level signal when DI’d to the house, so I was looking at picking up a Broughton HPF/LPF to add to the end of my chain. It was then I noticed my GK 700rbii has a woofer and tweeter high cut built into the EQ of the amp.

Anyone know if the woofer and tweeter high cut are acting as an additional HPF/LPF on the amp? (what I would be getting the Broughton for). If so I’m thinking can just run a post EQ DI through the amp and get a level sound through FOH with the overdrive?

Any help is appreciated!
 
#2
estimated_eyes said:
Adding overdrive into my chain (which is currently clean to amp) and want to make sure I maintain a solid FOH sound.

I started reading about LPF’s for help with a level signal when DI’d to the house, so I was looking at picking up a Broughton HPF/LPF to add to the end of my chain. It was then I noticed my GK 700rbii has a woofer and tweeter high cut built into the EQ of the amp.

Anyone know if the woofer and tweeter high cut are acting as an additional HPF/LPF on the amp? (what I would be getting the Broughton for). If so I’m thinking can just run a post EQ DI through the amp and get a level sound through FOH with the overdrive?

Any help is appreciated!
Click to expand...

The rb series heads are “bi-amp” heads. When used with the proper cabs and cables you can control the horn from the amp separate from the woofer. The high cut feature is more volume control than tone control. The 700rb would put 480 watts to a 4 ohm load and the separate 50 watt amp in the head would run the tweeter or horn.
 
#3
estimated_eyes said:
Adding overdrive into my chain (which is currently clean to amp) and want to make sure I maintain a solid FOH sound.

I started reading about LPF’s for help with a level signal when DI’d to the house, so I was looking at picking up a Broughton HPF/LPF to add to the end of my chain. It was then I noticed my GK 700rbii has a woofer and tweeter high cut built into the EQ of the amp.

Anyone know if the woofer and tweeter high cut are acting as an additional HPF/LPF on the amp? (what I would be getting the Broughton for). If so I’m thinking can just run a post EQ DI through the amp and get a level sound through FOH with the overdrive?

Any help is appreciated!
Click to expand...

The GK cross over is at 5kHz. The tweeter is always high passed, but the woofer can be run full range or low passed via the Woofer X-Over button. When you engage the Woofer X-Over button, the post EQ DI signal is also low passed at 5kHz. The Tweeter High-Cut rolls off the tweeter at 10kHz. I like to run the Woofer X-Over off and the Tweeter High-Cut on.

The Broughton would allow you to apply variable HPF/LPF as desired. IMHO, the variable HPF would be really nice to help dial in the amps low end. I wouldn't use a variable LPF myself, but YMMV.
 
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#6
estimated_eyes said:
Anyone know if the woofer and tweeter high cut are acting as an additional HPF/LPF on the amp?
Click to expand...

Yes. Essentially the woofer hi-cut can act as a LPF, but adjusting the HPF would actually be done via the 5-string button.

As noted, when the woofer hi-cut is engaged, it'll strip 5kHz+ from your cab if you're not bi-amping.

As for the difference between the amp in 4 and 5 string mode:
Edit, pasted the wrong one that was just from the send previously. The below is more accurate:

screenshot-2018-03-05-12-31-00-copy-png.png

Yellow and teal in 5-string mode.
Blue and Orange in 4-string mode.
 

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#7
Kro said:
Yes. Essentially the woofer hi-cut can act as a LPF, but adjusting the HPF would actually be done via the 5-string button.

As noted, when the woofer hi-cut is engaged, it'll strip 5kHz+ from your cab if you're not bi-amping.

As for the difference between the amp in 4 and 5 string mode:
View attachment 3299723
Click to expand...
I really like answers with numbers and pictures! :thumbsup:
 
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#9
Al Kraft said:
I really like answers with numbers and pictures! :thumbsup:
Click to expand...

Ah! Here's the shot I was looking for. Below is a screenshot of a couple sweeps I did that compared my 1001RB-ii preamp (same as in the OP's 700RB-ii) set with EQ dialed in for a flat response in 5-string mode, and then compared that to the amp in 4-string mode with the woofer hi-cut engaged. Note the low and high roll-offs, as well as a slight EQ shift from the combination as well.

Screenshot 2018-06-07 21.41.562.png


As to the OP's original question - whether the GK has some sort of HPF/LPF built in or not is really secondary to if they'll meet your needs. Hopefully the screens I posted can give a little bit of insight as to how much is being rolled off and how soon by the amp, but ultimately you'll need to test them out and see if you need a tool that offers you more flexibility than what your amp alone can give you in this department. Good luck!
 
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#11
Kro said:
Ah! Here's the shot I was looking for. Below is a screenshot of a couple sweeps I did that compared my 1001RB-ii preamp (same as in the OP's 700RB-ii) set with EQ dialed in for a flat response in 5-string mode, and then compared that to the amp in 4-string mode with the woofer hi-cut engaged. Note the low and high roll-offs, as well as a slight EQ shift from the combination as well.

View attachment 3299755

As to the OP's original question - whether the GK has some sort of HPF/LPF built in or not is really secondary to if they'll meet your needs. Hopefully the screens I posted can give a little bit of insight as to how much is being rolled off and how soon by the amp, but ultimately you'll need to test them out and see if you need a tool that offers you more flexibility than what your amp alone can give you in this department. Good luck!
Click to expand...


As stated, really appreciate the response with data to back it up! Very helpful, thanks!

I am currently running the amp in 4-string mode, so I am getting that low end cut-off, but will experiment with that woofer high-cut to take care of those high frequencies.

It's going to be something I need to play with to make sure it's still sounding good going to FOH. As stated, I have read that running a distortion pedal to FOH is going to sound really harsh unless those high's are rolled off via a LPF or, in this case, possibly just using that woofer high-cut and running my DI from the amp post-eq.

I gig frequently so I was hoping to get some information and get ahead of any possible issues.
 
#12
estimated_eyes said:
As stated, I have read that running a distortion pedal to FOH is going to sound really harsh unless those high's are rolled off via a LPF or, in this case, possibly just using that woofer high-cut and running my DI from the amp post-eq.
Click to expand...

A lot of that depends on the specific distortion you plan on running. Do you have that decided on yet?

Have you played around with the GK boost, or is this something you need to be able to turn off and on? I've found that the GK boost circuit appears to be optimized to limit HF distortion on its own by design.
 
#13
Kro said:
A lot of that depends on the specific distortion you plan on running. Do you have that decided on yet?

Have you played around with the GK boost, or is this something you need to be able to turn off and on? I've found that the GK boost circuit appears to be optimized to limit HF distortion on its own by design.
Click to expand...

I ordered a Way Huge Pork Loin that is on the way (looking to add a bit more hair to my sound for a few sections of a couple songs)

My current settings with the GK have the boost up, almost fully on. The OD is only going to be used for a couple songs, so it would not be on all the time. Without surprise, looks like I'm just going to have to wait until the pedal gets here to see how its going to react when running DI to house.
 

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