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Need help with my new GK 400RB IV

Discussion in 'Amps and Cabs [BG]' started by TVD, Aug 8, 2004.

  1. TVD


    Jul 14, 2004
    Hey everyone, i just did my first gigs with my new head, a GK 400RB IV, and was happy overall, but need some advice, and yes i did alot of searching here first(heh). I played with an SWR basic 350 for the past almost 14 years, and it's been a great workhorse. This year though, i've had it in the shop twice, and it's still not near right. It's not a good feeling on gigs just waiting for something to die, so i bought a GK. I bought GK cuz over the years when i've played other rigs GK stuff has always blown me away. Some of the gigs i do are fairly high profile, so it's really important i don't have gear issues.
    Anyhow, I have a standing gig at a sportsbar type of place on Friday nights, and this place is a nightmare for sound anyhow. Everything always sounds really middy and low endy in the room to me, but somehow still not boomy. The place is packed beyond belief every week, can't hardly walk in it. Never had this problem there with the SWR, but with the GK Friday night i had a really hard time getting a sound i wanted. There are "hot notes" in this place, especially in the key of F, F's and C's are murder, and when playing in those keys, i was having huge problems with overtones off the bass. Like i'd play a note, and it would just take off, this rude sounding overtone that took on an ugly life of it's own. When i tried to dial it out, i'd get a really thin sound i wasn't happy at all with, and felt like it didn't cut thru at all. I was never close to being happy. I messed around with it alot. About the best i got was setting the contour and presense flat, treble at noon or 1, high mid around noon, low mid around 9 or 10 o clock. Now i hated this cuz it sounded so much better with the low mid around 1 o clock, but that was a big source of my overtone problem right there. Bass around 11 o clock, boost around 9 or 10 o' clock, but again the boost sounded way better around 1, cept i kept getting that dreaded overtone. I started out with the master around 11 o clock, and the input volume at about 9, but when i dropped most of the settings under noon, it got so thin i moved the master up to around 1, and the input volume to around 11. Volume wasn't the issue though, all i got when i did that was a louder thin and crappy sounding tone. I want a big fat solid sound, that still has clarity w/o the annoying overtones. It's not a hollow stage at this place, it's only a few inches off the ground. Any suggestions for a room like this? Just refuse to play in the key of F or C or what? I also wasn't crazy about the highs in general, as compared to my SWR, just sounded a bit more muffled, but i learned quick that a slight adjustment on the eq of the GK goes a long ways. My cabinet is an SWA Goliath II 4X10. I play a G&L L-2500.
    Now the place i played last night, i didn't have any of the overtone problem at all. I thought it sounded really pretty darn good, though it still wasn't perfect and i'm getting used to the GK, though i really do like it alot. Maybe i was still a bit gun shy from the overtones the night before, cuz the soundman told me it sounded really good out front, but he added more low end out front than i was giving him from the stage.
    One other issue i had was a buzz when i didn't have my hands on the bass strings. When i was playing or had my hands on the strings, no buzz at all. Never had that with my SWR. It wasn't that bad with the GK, but it was there. Enough to annoy me. Something i notice alot more when i first set up with than when the gig is going. I was able to cut some of it out between the parallel-series switch on my G&L, but not all of it, also i could cut some out with the -14dB pad, but i liked the punchiness more without using that button, and if i turned up the volume to the volume i lost from that button, i was still in the same boat with the buzz. I guess it's a polarity-ground thing in the bass or something, but why would i hear it with the GK and not the SWR? Anyhow, any advice/tips would be apprecieated, since i have to play this room most Fridays. Thanks, Trent
  2. TVD


    Jul 14, 2004
    Anyone? I feel so ignored... :bawl: Trent


    Aug 13, 2003
    Sulphur LA
    I don't want you to feel ignored. But, as a former GK product rep. All I can say is that GK and SWR are totally different. I played SWR for years and liked it. When I went to GK it was a much faster amp, rather rude at times. That took some getting used to. I will close with this thought, use it for a bit more and take some comfort in the fact that the soundguy said you sounded OK. I hope this helps a little. :)
  4. I was going to ask bob gallien about the buzzing issue before I posted, but I forgot to do that today. I'll ask him tomorrow. what I do know about it is that passive basses tend to do that. I can't explain why one brand is more sensitive to your bass than others, but I've seen it happen the opposite way as well.

    Regarding your tone. it sounds like you're dealing with standing waves in that room. It's hard to say how to fix it without knowing what frequencies are effected, but based on what you've said, I would try this. keep the preamp volume around 11 oclock or lower. Keep the low mid down, but also turn the treble down to around 9 or 10 oclock. If you feel like you need a little more through the tweeter, use the presence control instead. Go ahead and set the bass to around 12 or 1 oclock. go lighter on the boost and maybe just a little contour. You could probably roll off a little of the high mid as well. As I stated in another thread, with GK amps, it's better to cut than to boost. But in your situation, knowing where to cut isn't always easy. Another idea is to tilt back the cabinet so that it's aiming directly at your ears. That way you can reduce the overall volume a little but hear yourself better.

    Possibly none of this will help you. just give yourself plenty of time in the room before the gig to learn the amp. Don't be afraid of extreme settings with the gk amp either.
  5. TVD


    Jul 14, 2004
    Ok, this may be a dumb question, but can you go into a little more detail by what you mean by the GK is a "much faster amp" than an SWR. Do you mean it processes the sound faster, or the sound is released thru the speakers at a faster rate? or a solid state amp as opposed to the SWR that as an all tube preamp?
    About the buzz issue. What i really noticed in playing with it some more is it almost all goes away if i get get away a bit from the amp. Another thing with the room with the bad sound i play every week is the stage is so small, i'm probably less than a foot from my amp at all times, and two feet tops. Pretty much right on it. My old amp prob smells like ass from playing there for a few months... :D Trent
  6. motorhall


    Jul 1, 2004
    Sounds like that room is very resonant at a certain frequency. I have the same problem in my house - low E and F just make the room come alive and buzz like crazy. Since most amps use tone pots that are centered around a certain frequency, you can't minimize those frequencies without affecting everything else. The SWR and GK heads probably have different center frequencies for their bass tone controls.

    Do you have an effects loop? I play classical organ and the only way for me to tame the bad frequencies in my house without killing all of the low end was to use a graphiq EQ. The more bands you have to play with, the better. I would guess that you are going to have to cut somewhere around 50-60hz. Most tone controls on amps are centered somewhere between 80-150hz.
  7. TVD


    Jul 14, 2004
    Yeah, the amp has effects loops capabilities, but i've never messed with or owned a graphic eq. It was kinda funny, we have to play this ^%%*& song that i hate at this place at least twice a night. It's in F. Well, i was really happy with the new GK head till then, this was during the first set. In fact the leader/guitarist said man that thing sounds great. Well, we get to that song, and it starts out with diamonds on the F at the start, i play it as an octave thing, use the low one 2nd. When i did, i got my first real taste of the ugly overtone, and he was looking at me with a "What the....." look. I just ended up turning down for the rest of that song, but that didn't thrill the band much, you know how it goes for bass players if you're not "there" every note, and this band is only a three piece, so..I was still playing, but not very loud. The overtone is kinda weird too. The note sounds good at first, but then like gets really loud at the end of it, and it's really not an F anymore, just a rude and loud sound. Almost like feedback in a way. Like it plays the note fine, them it catches something in the room, and takes off.
    When we took a break, i spent the whole thing trying to dial it out on those notes, but ended up with an overall tone i wasn't happy with as a result when i did pretty much get rid of it. Maybe i'd be better off just turning down when i know that big ugly F note is coming in this room, though C was about as bad. Trent