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Biamping question

S

Scott549

Oct 26, 2009
427
11
Madison, Wisconsin
www.willsband.net
#1
Could someone explain how the biamping feature works with something like a GK 800RB? Do you need separate inputs on your cabinets for the different speakers? I have a 1 x 15 and a 1 x 12; both have two inputs but they are not separated for the woofer and tweeter in the cabinet.

After my Backline 600 produced a burning smell over the weekend it got me thinking I might need another amp; I could then use the BL 600 as a backup.
 
#4
The 800 RB has a 300 watt amp for lows, 100 watts for highs, so it can drive a high efficiency cone mid/high driver or a tweeter. A tweeter, (horn or sealed back) by design, is isolated from the woofer and doesn't need a separate cabinet. A conventional cone mid/high speaker should be in a separate enclosure or closed compartment in the main enclosure.
 
#5
gigslut said:
The 800 RB has a 300 watt amp for lows, 100 watts for highs, so it can drive a high efficiency cone mid/high driver or a tweeter. A tweeter, (horn or sealed back) by design, is isolated from the woofer and doesn't need a separate cabinet. A conventional cone mid/high speaker should be in a separate enclosure or closed compartment in the main enclosure.
Click to expand...

My Ampeg PF-115he cabinet has a woofer and a tweeter in it. How would I connect this with an 800RB to use the biamp feature?
 
#6
Scott549 said:
My Ampeg PF-115he cabinet has a woofer and a tweeter in it. How would I connect this with an 800RB to use the biamp feature?
Click to expand...

You wouldn't. Set the amp to fullrange, plug straight in, and let the cabs internal passive filters take care of it.

Except for the 800, the rest of the GK "rb" series amps have a fixed crossover point of 5khz and a 50 watt amp to power tweeters separately from the woofers, that's the extent of the "biamp" feature.

The 800rb is special. It runs a 100 watt, 8ohm minimum high amp, with a crossover that's adjustable from 100hz to 1000hz. That's not high enough to use as a tweeter amp, you'd fry the tweeter in short order. It's really for running something like a subwoofer + top, or in my case, a couple of woofers and a 6" mid cone. It's available crossover settings and power distribition make sense in those cases.

When set to full range, both amps still work, so in your case, assuming these are 8ohm speakers, or at least one is for the high amp, you can run each one on it's own amp to balance volumes between the 2, or hold back whichever one farts out sooner, etc.
 
#9
will33 said:
The 800rb is special. It runs a 100 watt, 8ohm minimum high amp, with a crossover that's adjustable from 100hz to 1000hz. That's not high enough to use as a tweeter amp, you'd fry the tweeter in short order. It's really for running something like a subwoofer + top, or in my case, a couple of woofers and a 6" mid cone. It's available crossover settings and power distribition make sense in those cases.
Click to expand...
Good catch! I sold mine years ago and forgot the crossover select topped out that low.
I ran mine with one or both of a pair of D140s fitted with 2225 cones and coils for lows, and a K120 in a small sealed box for mid/highs, Xed over at around 500. I did occasionally use a large bi-radial horn and driver at outdoor events. It was rated down to 800 hz, so handled it easily.
 
#10
You can use the biamp as intended. The 12" cab will only be doing mids and highs, so not adding much volume but the sound will be very good.

Listen very carefully to the 15 for overexcusion. The 12 with 100W of mids and highs can get a whole lot louder than the bass output from the 15, relatively speaking.
 
#11
Not to hijack the OP but the 1001RB II doesn't have a "fullrange" switch right? I use two 410MBE cabs and they don't have the HBA system. I just run a speakon from one output from the amp to one cab and run another speakon from the second output of the amp to the other cab...is that correct? Not using the "Tweeter" control...just the "Woofer Master". Thanks.
 
#12
mello_bedwetter said:
Not to hijack the OP but the 1001RB II doesn't have a "fullrange" switch right? I use two 410MBE cabs and they don't have the HBA system. I just run a speakon from one output from the amp to one cab and run another speakon from the second output of the amp to the other cab...is that correct? Not using the "Tweeter" control...just the "Woofer Master". Thanks.
Click to expand...

With the MBE cabs the tweeter amp is not being used (either with speakon or 1/4" cables). Only the "Woofer" control will be active (in full range mode unless you engage the "woofer Hi-cut" to cut frequencies above 5KHz).
The "Woofer Hi-Cut" is the bi-amp switch.
 
#13
B-string said:
With the MBE cabs the tweeter amp is not being used (either with speakon or 1/4" cables). Only the "Woofer" control will be active (in full range mode unless you engage the "woofer Hi-cut" to cut frequencies above 5KHz).
The "Woofer Hi-Cut" is the bi-amp switch.
Click to expand...

Okay. I was just saying how I have the amp hooked up to the cabs...with two separate speakon cables, using both speakon outputs that are on the back of the amp. So I want to have the Woofer Hi-Cut button "out" so it isn't engaged and use the Woofer/Master control for the volume output. Sound right?
 
#17
LiamPodmore said:
The GK Bi-amp Feature is for use with GK's cabs that also have that feature. You need a 4-pole speakon cable instead of 2 pole to make use of this feature. It can only be done with GK cabs, no others.

Liam
Click to expand...

It can be used with other cabs but requires rewiring the cabs. Even then the crossover is at 5KHz a point decided for horn tweeter use. The feature only works with the high end G-K cabs like the RBH, NEO, SBX, RBX cabs.
 
#19
Running 2 independent amps into different speakers, usually with different frequency ranges. Often both amps are in the same head unit and the head unit has a built in crossover to send lows to one amp and highs to the other. The amp for the highs is usually a lower power rating than the one for the lows as the highs need less power. Some cabs have a biamp option, meaning that the tweeter and woofer can be separately connected to the 2 outputs from the 2 amps.

This allows you to control the highs and lows separately and sometimes even the frequency they cross over at.

Another version of biamping is to run a clean rig (bass to amp to cab) and a dirty rig (bass through effects to amp to cab). Often the clean rig will be EQ'd to have more lows and the dirty to have more highs. This allows you to go crazy with effects and still have some definition.
 

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