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Adding a Guitar Amp to produce clarity and mid-voicing.

Discussion in 'Amps and Cabs [BG]' started by Flux Jetson, Oct 2, 2012.

  1. I tried doing this a few times. I split my preamp output signal with part of it going to a dedicated power amp, then out to bass cab. The other portion going directly to a guitar amp, set up with an appropriate EQ to support the sound I'm shooting for. Add a bit of HPF to the Guitar Amp feed so the speaker doesn't bottom out. The guitar amp feed can be post preamp, or pre-preamp .. whatever flicks yer thrillswitch.

    This seems to work really well. I haven't done it at a gig ... yet! But I'm certain I will at some point soon (as soon as my drummer heals up his injured hand).

    I've used a Line 6 Spider 75 (2x12 open back). The Spider offers so many variables with the different amp models et-al, that I was able to dial in any number of great tones. It seemed to ~meld~ with the bass amp/cab sound just fine, and didn't sound like two different sounds mushed together.

    Next test will be using the Spider as just a preamp, and using a 100 watt power amp to drive one of my custom guitar cabs -- a 2x12 open back with Celestion V-30s. I'll see how that works out.

    This type of approach seems more tunable and flexible than using 3-way bass cabs with fixed crossovers. Or even some of the 2-way cabs that use a woofer and a 6" driver with a fixed crossover. You have so much more control over everything with the guitar amp setup. Like the total volume of the midrange, the tonal coloring and actual ~sound~ itself of the midrange freqs. As well as where the midrange is actually ~tuned~. Unless you have a bass cab with a totally tweakable crossover, you're stuck with where the midrange driver is tuned, and how loud it is, as well as what the midrange driver actually ~sounds like~. You get what the cab builder has decided is *good*, and you're gonna like it, dammit! Heheh ... :)

    Anyone with like experiences, or comments about this type of approach?

    Thank you! :) And Happy Full Moon!

  2. goldenglory18


    Nov 30, 2009
    Los Angeles
    Your Mom.
    Awesome idea. I'd love to hear sound clips if you have them.
  3. None yet, I gotta get busy with that. I have several people wanting audio demos of some other stuff I'm doing too (see sig).

    I think I'd need to do mic'd recordings to properly demonstrate this. I'm not sure I have the right gear to do that very well. I suppose all I can do is try it, it's either FAIL or WIN. :cool:

    Thanks for the props! :)
  4. JGR

    JGR The "G" is for Gustav Supporting Member Commercial User

    Jun 29, 2006
    President, CEO, CFO, CIO, Chief Engineer, Technician, Janitor - Reiner Amplification
    Yup, there are some cool tones to be had. My DB680 has a crossover section built in, and I got some good results running the top into a Marshall 412 and the low end into my NV215. There is a clip on my Youtube page somewhere...

    Ultimately I decided to build my own cabs (sealed 15+8) and I think it works even better - sounds more coherent/natural. Maybe it helps being a guitar player as well, I dunno, but they came out really well IMO, and even sound killer on high gain electric which is extremely revealing.
  5. kringle77

    kringle77 Supporting Member

    Jul 30, 2004
    Massena NY
    Sometimes it can be tricky to get the right mix. You could get away with using a 1x10 guitar amp and an 8x10 bass amp as far as output goes. I have gotten a good billy sheehan kind of tone mixing my bass amp with an old peavey guitar amp before. Sometimes, the crappier the guitar amp the better for this, I find.
  6. Right on.

    Y'know, it's crazy how easy it is to develop sounds if you just give it a go. So many folks are happy to just use whatever various amps and cabs sound like. Using some of the "left field" ideas I employ produce stellar results for me, and I don't end up going on the well beaten path of endlessly buying amps, cabs, stomps, basses etc .. searching for ~that~ sound (what it might be). Been there and back. Too many times.

    This latest setup I've been using is so bloody flexible, I think once I finish the framework it will suit me for the rest of my life, no matter what my tastes or needs evolve to.

    How are you powering the sealed 15+8? Bass amp w/crossovers? Or are you still using a guitar amp to drive the 8"?
  7. Ain't THAT the truth!

    And I agree, it doesn't take much to get the results. A little practice amp is usually enough. Some little Boss CUBE or a Line 6 thingy would do it.

    With the amount of sounds those little modeling amps produce you have room to try different things until you find The Grail. And with footswitching channels you have realtime tonal options online at any given second.
  8. Dave W

    Dave W Supporting Member

    Mar 1, 2007
    White Plains
    I had some good results plugging my Attitude into my bass amp and a 5150. It's going dual outputs, so I sent the "low" side (the EB0 mudbucker) to the bass amp, the the "high" side (the P pickup) to the 5150. I never tried gigging it though, I wouldn't have enough room in my car to fit the 5150.
  9. Well, yea ... there is ~that~ to deal with I suppose. I'm fortunate to own a pickup truck.
  10. Dave W

    Dave W Supporting Member

    Mar 1, 2007
    White Plains
    I had a truck, and I'm not sure I would have bothered lugging it out then. Most of the place we play I wouldn't have enough room to fit it. It's the 2X12 combo and is bigger than my guitarists amp, a Twin.
  11. iiipopes


    May 4, 2009
    You have described what has become "classic" bi-amping. Several manufacturers, such as GK & Carvin, make bi-amp heads as stock items, and sell a variety of speaker cabs to go along with them. Welcome to bi-amping.
  12. Goteky45


    Oct 30, 2009
    what HPF filter do you use? I' ve been wanting to try this for a while but I lack an HPF. Is there a good/reliable and not very expensive rack mount one?
  13. Well, it's not really the same at all. With the bi-amped setups available from most manufacturers you don't have separate EQ stages for each channel, do you? I mean, your sound is run though one single preamp signal chain, and then split into two separate signals after the EQ and other gain stages, right?

    With adding a guitar amp you have 100% control over all aspects of the sound that is routed to the added channel. With "classic biamping" as you've described you simply get a crossover that routes the signal to another cab. Not really providing a second EQ or second set of gain stages. you can add them post EQ/post crossover, but the point is that theose features aren't there, they must be added. So those "biamped" amps only provide the split-off channel to be honest.

    And with the cabs you're speaking of, you're trapped once again with their choice of speaker and cab. So while what I've described is one form of biamping, Carvin and GK aren't offering what I'm talking about doing at all.

    Perhaps they offer SOME of the tools needed to assist with this setup, but they are sorely lacking when the two ethos' are compared.

    With the setup I'm speaking of you have total control over which cab, which speaker, which EQ settings, which gain structure (overdrive, distortion, compression, et al) you wish to use that are completely and totally separate from your actual "low end" amp/cab.

    Please correct me if I'm wrong.
  14. You can use something as simple as a graphic EQ, there are many stombox-type graphic EQs out there already (Boss, MXR to name two of them). A parametric EQ would also work just as well. There are any number of ways to "shelf" the low end.

    ART offers the Pro Channel II for $299 (street), it's a rack mounted mic preamp that works just great for bass, it has two semi-parametric EQ stages, as well as a low end roll of (aka HPF). It also has a great little compressor, and a very handy VU meter as well as a few other features. For $299 it's tough to beat. ART also has inexpensive 2 way and 3 way rack mounted crossover networks that might suit your needs in the same role. Hit their website.

    The stompbox graphic EQs are half that price and would also perform this task. There are other ways to go that might be better though.
  15. jason weatherby

    jason weatherby

    Aug 30, 2012
    Sounds like a great idea. I think John Entwistle did the same or a similar thing - using guitar amps with his bass to cut through the mix. Even better, try it with a stereo Rickenbacker with the neck pup into the bass amp and the bridge pup into the guitar amp.
  16. JGR

    JGR The "G" is for Gustav Supporting Member Commercial User

    Jun 29, 2006
    President, CEO, CFO, CIO, Chief Engineer, Technician, Janitor - Reiner Amplification

    I'm just running full range into my tube preamp into a poweramp and then the cab. The 15 stays clean and the 8 adds the brightness and breakup/crunch to the mids and top end. I went through several iterations of crossovers and different 8's to get the sound I was after but I'm pretty happy with how it has turned out.
  17. will33


    May 22, 2006
    I've gotten some way cool sounds with it at home with a small bass cab or 2 and a Valve Jr. pushing a couple different types of guitar speakers I have (eminence models). I haven't scaled it up to gig worthy levels yet, but I too want to do a sealed 15 using the Definimax 4015LF and find the right guitar speaker for topend.

    I also prefer my biamp capable bass heads for the reason you describe, being able to control the crossover frequency and power distribution between the 2 halves. It's gonna take me quite a while to come up with the right passive XO and driver spl matching, or rather intentional mismatching to sound how I want it, but eventually, it will be done, so I can put a huge tube amp on there and do away with the biamping for that particular rig.
  18. Caca de Kick

    Caca de Kick Supporting Member

    Nov 18, 2002
    Seattle / Tacoma
    The guys from Kings X, Cheap Trick, and Galactic Cowboys have been doing this for decades.

    I don't do it as often as I wish I could, but when I have the room onstage or an outdoor show, I keep the big rig clean (ish), and split the signal to a small B rig that runs two stages of dirt and some flange.
    Independant eq'ing is what makes a huge difference over bi-amping.
  20. That and the separate gain staging ability as well. It's so much better than just ~biamping~ in the traditional sense, at least I feel that way anyhow.

    I know this is nothing new, I'm a HUGE ELP fan, have been since 1973. Greg Lake was kind of one of the early pioneers of this idea, using very large "bass bins" combined with "Acoustic lenses", both powered by their own Crown amps. He wanted his Jazz bass to sound like Keith's piano.


    Greg and his J in the early days of ELP before he went to Alembics ...