Why aren't bi-amp heads more common?

[brianrost]

GK's biamping was always a lot different. The first biamp head, the 800RB was 300W + 100W, and the later heads as noted had only 50 watts for the highs. Other manufacturers' biamp rigs had equal power to both channels. You don't need hundreds of watts to drive a tweeter.

This sort of biamping is done in most powered speakers, both studio monitors as well as PA cabs. In such a self-contained system, matching the wattage to the drivers is just common sense.

 

[MisticoRitualista]

That is technically a bi-amp head, but it is not really a bi-amp setup in the traditional sense. The 800RB was a true bi-amp which could use 300w only for the lows and 100w for the mids/highs. GK sold cabinets specifically for use with that amp setup, a 115 for the lows and a 212, basically a guitar cab, for the mids/highs. Most people then and still today never use the 100w amp and just run the 300W amp full range. The 700/1001RB is full range with a small 50w amp only for the horn. The only reason the 700/1001RB has this is so you can overdrive the main amp to get the GK " and keep the horn clean. That is the one advantage over running a cabinet full range since distortion through a horn/tweeter usually sounds bad.

This makes sense, thanks

 

[dbsfgyd1]

A few years ago I finally got myself a legitimate rig. After doing a little research I landed on two potential options, the Aguilar Tone Hammer 500 or a Gallien-Krueger 700rb mkii. I landed on the GK & paired it with a Neo 212 ii cab & have been very happy with it.

The 700rb mkii is a bi-amp head & states that it is 480 watts for the low end + 50 watts for the highs running into one or two 8 ohm cabs (which the Neo 212 ii is) or one 4 ohm cab.

I just purchased another Neo 212 ii cab & am picking it up tomorrow. Im excited to hear the full potential of the head with both cabs & it got me thinking more about the bi-amp system in general.

What are the advantages &/or disadvantages of the bi-amp system? Why isn't it more common to see this tech in amps & what type of system is currently most popular in amp heads?

*I apologize if this topic has been discussed in another thread or threads*

‘Eden WT 800 heads were stereo amps with a built in crossover for biamp purposes. Vintage Peavey Mark IV heads had a built in crossover designed for biamping, so this is not exactly cutting edge.

The reason biamping has gone the way of the dodo is because speaker cabs today are designed to be full range. Unless this is something you want to explore in pursuit of your art, it’s really a lot of wasted time and energy and cost.

And this is from a guy that used biamp rigs back as far as the 70’s, in the mid 80 to the mid nineties, cobbled together some thing like what your are trying to accomplish with a Peavey Mark IV and a Dean Markley guitar amp, and today still has an Eden rack system with zero market value (see avatar) which was designed for biamping purposes.

That said, 99% of my gigs today I use a WD-800 and one 210 Eden D-XST cab. And after my meeting with our sound company next weekend, I may become 100% ampless.

 

[dbsfgyd1]

A simple and cheap option is pick up a guitar combo, run it off your line out. As long as the line out is pre EQ, just roll off the lows on the guitar amp.

I’ve done this…it does clear up your sound on stage The problem if it isn’t clear on stage without the guitar amp, it’s going to be a lot less clear in the house guitar amp or not.

 

[agedhorse]

There still seems to be a lot of misunderstandings about what biamped, what it does and why.

A biamped system is 2 power amps, one powering the low frequencies and the other powering the high frequencies. The crossover is BEFORE the power amps, splitting the signal into the low and high bands using an active crossing consisting of a low pass filter (low out) and a high pass filter (high out). Sometimes the low out can run full range too. The crossover point varies with the application, sometimes it’s for the tweeter and it’s roughly 3.5kHz-5kHz and sometimes it’s much lower for a subwoofer or additional low frequency support.

It was originally used to increase the high frequency volume and clarity back when amp power was very limited. You could clip the low frequency section and cover it up with the undistorted high frequency section because high frequencies require much less power to amplify.

Biamping also reduced losses in the passive crossover, as well as reducing the size and weight of the large (and expensive) passive parts in a conventional crossover. This is more important at low crossover frequencies where the parts are naturally larger.

 

[DonaldR]

I attended a Peavey clinic like 30 years ago. Their concept of bi-amping was to have your low frequencies untouched in one amp and your high frequencies "effected" on on another amp. So the chorus, reverb, delay, etc. where sounding really nice as they were not affected by low frequencies. Effect pedals with blend or dual path didn't exist back then.

 

[MarshallAC50Stack]

Around 1990 I put together a biamped Walter Woods/Bag End rig with a 210 on top and an extended range 115 on the bottom. The plan was to use the full rig on the big gigs, and have a modular choice of cabinets for everything else. The one time I used the whole stack was fun. The large 115 sounded excellent but was a pain to move. It didn't take long to figure out how useful the 210 was. I sold the 115 P.D.Q. and learned that for my needs, a two channel pre with a mono power amp was a better choice.

 

[BassBrass]

I tried them when they appeared briefly in the late 80s or was it early 90s?... they aren't better. Nothing sounds better than a full range sound with mids in there eq'd to taste including lowpass for too low freq. if necessary. That's what punches through a live mix.

 

[micguy]

I've played the vast majority of my gigs the last 10 years (and all of them the last 3) without any amp or cabinets. I'm also one of those people who sees no need for a tweeter on a bass amp, so although I understand why you might want to biamp in certain situations, a bass rig (for me) has never been one of those situations.

I reserve the right to change my mind, but 45 years of doing things without biamping on a bass rig seems to suggest that the likelihood of that is remote.

 

[jtemple]

I have the GK700RB ii with a Neo 410. With one cable (GK proprietary speakon) I can run the amp in bi-amp mode going into the 410. I do notice a difference and I think it really enhances the sound. Just my opinion.

 

[MarshallAC50Stack]

I have the GK700RB ii with a Neo 410. With one cable (GK proprietary speakon) I can run the amp in bi-amp mode going into the 410. I do notice a difference and I think it really enhances the sound. Just my opinion.

That sounds like a great rig. If that’s a full range 4x10 with the separately powered horn it makes total sense.

 

[agedhorse]

I have the GK700RB ii with a Neo 410. With one cable (GK proprietary speakon) I can run the amp in bi-amp mode going into the 410. I do notice a difference and I think it really enhances the sound. Just my opinion.

It’s not a proprietary cable, it’s a standard 4 wire cable with NL-4 plugs wired straight through per the Neutrik standard. Pro audio has been using this configuration for ~30 years.

 

[Thumpin6string]

Since I play BASS, I turn down the tweeter and the treble and use a LPF. I own a 1001RB which is biamp able. I see no need to use the treble amp. Treble is for other instruments, not bass IMHO.

 

[DJ Bebop]

I did it as a kid because I wanted to recreate the sound of the playback I heard in the studio, live on stage for my bass rig.

At that time, few if any local PAs where bi-amped or carrying instruments other than keys or horns. So your rig has to carry the venue. If you enjoyed playing your bass through a glorify guitar amp fuzzing and straining away to just be heard and no low end, you were fine without bi-amping.

No me though

As bass amps and cabs got better at low bass reproduction and better PA systems to run through, not needed anymore.

Having said that, the last of my bi-amping gear I still use once in a while, Carvin BX 1500. In my later year's I gave up my racks and power amps for it.

 

[DJ Bebop]

Having said that, the last of my bi-amping gear I still use once in a while, Carvin BX 1500. In my later year's I gave up my racks and power amps for it.

Full bi-ampable head

 

[Wasnex]

I used to have a GK700rb (not sure which version). Doesn't the biamp feature just give you a control for the tweeter volume on the face of the amp? Many modern cabs simply have a control on the back of the cab for the level of the tweeter so it's really not necessary IMO to have that on the face of the amp. Of course I might be completely wrong in how the biamp feature was working for me.

One of the intended advantages of the GK system is you can push the woofer into grind territory, but the signal path for the tweeter stays clean.

The Boost circuit was intended to emulate a driven tube. The signal is split after the Boost control. One path is for the tweeter, and the other path goes to the Boost circuit.

This image was lifted from the 700RB mk1 OM.

 

[Manticore]

I tried bi-amping long ago. Ric 4001 with Ric-O-Sound engaged. I could tell the difference, but no one else knew when I didn't use it live. I tried later with a bi-amping head using standard outputs on the Ric, and later an Alembic. I could hear the difference live, but again no one knew when I used a standard full-range setup. As no one else knew when I bi-amped and when I didn't there didn't seem to be a reason to bring a second cab when one would suffice.

 

[Wasnex]

So from what Im hearing it sounds good solo in front of the cab but doesnt translate well in a mix, is that right?

Not necessarily IMHO.

It's more like this. Modern cabs are really well engineered. In contrast, old-school biamping generally involved slapping together random components with a fairly low-grade crossover. In other words, there was not any serious engineering involved to make sure all of the components worked well together to produce any sort synergy.

To build in the engineering, you select the right types of drivers and you use a speaker processor that allows you to precisely tailor the frequency response of each driver. You alos apply a bit of delay to phase align the drivers, so they integrate well through the crossover region.

So if you have the skills, money, and time, you can build a biamp rig that will sound outstanding. But since modern passive cabs are so good, it's probably not really worth it.

For the record I have run 5 or 6 biamp rigs. The only one that left we wanting used a BBE 383 preamp, which is I bought because it was super cheap. The sound was not bad, but it was not great. However, to be fair the speakers I used were old junky PA cabs, and the preamp/crossover and power amp I used were new, but entry level.

I currently own a mk1 GK 700RB/112 combo and also a pair of older GK 2000RB heads, which have a variable crossover and two power amps. IMHO these are still very good sounding amps.

The limiting factor in the GK combo is the way the speaker is tuned. It tends to sound sort of loose and wooly down low, which is the opposite of what I prefer. If I elevate the cab by at least 18", IMHO it sounds way better/less woolly.

For comparison, my last touring rig used primarily an Eden D210XLT pushed by 250W. The Eden had significantly more headroom and punch than the GK combo, and it sounded tighter and more focused down low. But I struggled to get the nice smooth high mids I like. The Eden tends to have sort of a crunchy quality in the high mids. The GK combo was too loose down low for my taste, but the mids and highs were way more HiFi and smooth.

My intended point is neither was perfect.

 

[agedhorse]

[QUOTE="Thumpin6string, post: 27403838, member: 242304" rat]Since I play BASS, I turn down the tweeter and the treble and use a LPF. I own a 1001RB which is biamp able. I see no need to use the treble amp. Treble is for other instruments, not bass IMHO.[/QUOTE]

Yet other players prefer something different.

 

[DaveParker39]

It’s not practical, and people aren’t nostalgic about it.
The one-two punch of obsolescence.