Dismiss Notice

Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Help! my GK amp sounding bad with low notes

Discussion in 'Amps and Cabs [BG]' started by Macron69, Aug 3, 2003.


  1. Macron69

    Macron69

    Mar 24, 2000
    Puerto Rico
    specifically a GK 700RB 2x10 combo amp.

    When i play low notes on my amp it starts to sound distorted,fart like to be precise. This only happens when i crank up the volume. am i doin something wrong on my volume settings? maybe overdoing the woofer and volume?


    any of you have any experience on this? thanks fer yer time.
     
  2. griff1676

    griff1676

    Jul 17, 2003
    Dekalb, Il
    What do you have your EQ settings on? Too much bass or low mid combined with turning it up will make the speaker travel too far, thus the "farting" sound. Do you have the 4/5 push button on 5? That could also be the problem. Hope this helps.
     
  3. Macron69

    Macron69

    Mar 24, 2000
    Puerto Rico
    As a matter of fact, i do have a similar setting to the one you describe. I crank up the low mid, some treble. bass knob sometimes gets past 12 o clock. i switch the 4/5 button depending on the bass. my main axe is my 5 string, so that button stays at 5 most of the time.

    btw, my 5 string has active electronics, and i was wondering if the bass active EQ may influence the output all the way to the speakers.i'm at this constant debate balancing bass preamp EQ with the amp's own EQ...Well, that may just be topic for a new thread...
     
  4. ChenNuts44

    ChenNuts44

    Nov 18, 2001
    Davenport, IA
    Boosting low frequencies on your bass will affect what goes into the speakers as much as boosting low frequencies on your amp.

    Bass low eq boost + 5-string button + amp low eq boost = great potential for farting. ;)
     
  5. bben

    bben

    Feb 28, 2002
    Santa Fe, NM
    Only other thought - make sure the boost knob is somewhere between 9 and 12 o'clock.
     
  6. ChenNuts44

    ChenNuts44

    Nov 18, 2001
    Davenport, IA
    It's not a bad suggestion, but the Boost knob shouldn't cause farting. Any distortion it would cause should be consistent over the entire range of the bass, not just with low notes.
     
  7. RicPlaya

    RicPlaya

    Apr 22, 2003
    Whitmoretucky MI
    On the GKRB4000III there are two knobs called voice filters I think, they are between the volume and eq, turn these completely to the left(off). Then adjust the eq to where the farting sound cant be heard. I rarely use these settings on my head when I do it seems to distort my sound as well. With these turned off I can almost boost my bass and mids all the way up with no distortion. Also do you have the 15" combo? When I switched to a 4 x 10 from a 15 that helped tremendously with distortion. The 4/5 may make a little difference if you put it on the 4 string setting. GK heads can be a little tricky at first to get dialed in, there is also the master and boost settings, those are the 2 knobs all the way to the right, I play the master all the way up and boost about half way, this allows me to play the volume at about 1/4 in my studio, that seems to clean it up..keep messing with it, you should be able to get your tone without distortion..good luck.
     
  8. My RB 700 will have the same issue if I boost the bass side of the Active electronics in the bass. Besides the 2x10s aren't as deep as some other cabinets.

    I'd say mess around with all of the bass levels (pre-amp in bass) pre-amp on the amp and also the contour control. They all end up interacting with each other.
     
  9. geshel

    geshel

    Oct 2, 2001
    Seattle
    Except that, with the bass boosted on the bass's EQ, the low notes will be coming in at a higher amplitude than the rest. So, they are more likely to overdrive the preamp.
     
  10. Macron69

    Macron69

    Mar 24, 2000
    Puerto Rico
    Thanks for all your suggestions. i'll try all of yor ideas as soon a i get the chance. this dilemma has me to the point that i have my bass preamp settings all flat and i use the amps EQ in order to avoid the bad sound.

    another question, if i were to add an extension cab, will the bad sound still be present if let my current settings intact?
     
  11. ChenNuts44

    ChenNuts44

    Nov 18, 2001
    Davenport, IA
    I was referring to the "Boost" knob on the GK amp, just for clarification. Still, your point it valid, as is mine. IME, the Boost circuit isn't subject to the nastier overdrive of the first gain stage in the preamp.
     
  12. ChenNuts44

    ChenNuts44

    Nov 18, 2001
    Davenport, IA
    Not a bad idea. If absolutely necessary, I'm sure you can still boost lightly if the need arises on the gig without compromising your sound much...but be careful;)

    It depends. Your GK cab will sound exactly the same with the same settings...IOW, it will continue to fart as it always has. However, if your extension cab can handle the lower frequencies and greater cone excursion, then it very well may not fart and could, in fact, sound quite good. In order to completely eliminate the farting sound, you'll need to reevaluate your settings or rely entirely on extension cabs, effectively rendering the cabinet housing your head useless. Good luck.
     
  13. bben

    bben

    Feb 28, 2002
    Santa Fe, NM
    About the boost knob - my son was using my 700RB and for some reason turned the boost knob all the way down and the volume all the way up to compensate. The amp sounded lousy and farty and low on power, and I thought it was ready to go into the shop until I noticed what was going on with the boost knob. Personally, I tend to run my GKs with the boost at about 11:00 o'clock or 11:30.
     
  14. You're running out of headroom in the preamp. set the preamp volume to about 10 oclock, increase the boost to about 12 oclock or higher and then use the woofer knob to set your volume level.

    GK Amps are meant to be used with the boost at least partially on. 12 oclock is a good starting point, but you could turn it all the way up without any risk if you want. Just keep in mind that the higher you turn the boost knob, you will need to compensate with the woofer volume knob.

    We have noticed that our 210 combo doesn't handle the B string at high volume levels as well as we would like it to. The above settings seem to work to some degree, but a 410 or 115 extension cabinet will give you great tone at the volume level you need. The GK SBX cabinets are shipping now and sound great.
     
  15. Daniel -- Where can we get some info on the new SBX cabs??
     
  16. Macron69

    Macron69

    Mar 24, 2000
    Puerto Rico
    Yeah, where?