Help getting more sound out of my subwoofer (trip?)

Discussion in 'Amps and Cabs [BG]' started by Eric Cioe, Feb 23, 2003.

  1. Eric Cioe

    Eric Cioe

    Jun 4, 2001
    Missoula, MT
    I have a low end problem.

    I run a Gallien-Kruger 400RB-III (preamp volume 5, master volume 4) head driving an Avatar 2x10 (150 watts at 8 ohms, plently loud, with a lot a rooom to be louder on the master volume), with the effects send from the GK running into the input of a bridged (with volume on max, never ever clips, not even close) Carvin DCM1000 power amp, running 700 watts at 8 ohms into a Yamaha SW 1x18 PA sub. Yesterday just for giggles, I cut the 2x10 out of the picture, I boosted every bass control (on my bass and amp) and cut all the highs. The carvin was just barely clipping, and the sub was about 2x as loud as it normally is. I would like to have more room to turn the sub up (and my whole rig, I have plenty of play left with the master of the GK and Avatar) with my normal tone. Any ideas?

    I need to get a crossover, to cut all the bottom out of the 2x10 (it bottoms out on about B, an octave above low B), but will this help make the 18 any louder? I guess I need more signal going to the power amp, but since GK put the dumb ass 'distortion past 5 on the preamp volume' feature on this amp, I don't have any room there. My volume on my power amp is max. What do I do? Trip, do you have any idea?
  2. Whappo Grande

    Whappo Grande

    Feb 9, 2002
    Santa Clara, CA.
    Manager: AccuGroove Speakers
    First I would run the Gallien-Kruger 400RB-III master volume all the way on. Then I would adjust the preamp volume starting at about 2.

    Next I would run your line from the DI output not the "effects send" to the Carvin.

    While this may not completely solve the problem, it's a good starting point.

  3. Cantstandsya


    Jul 27, 2001
    Fontana, CA
    Eric,I spoke with Trip tonight and he asked me to play messenger for him.He is out of town on business for a couple weeks and will get back to you as soon as he can.:D
  4. Eric Cioe

    Eric Cioe

    Jun 4, 2001
    Missoula, MT
    Thanks guys.

    My reasoning behind not using the DI out on the head is because I generally run that signal to the house for our shows. I suppose I could pick up a DI box too, but I just wondered if there's any way I could keep using the built in DI.
  5. The Yamaha sub isn't that much of a subwoofer. Considering it is just short of 10 cubic feet external volume, you'd think it hit those lows, but it does not.

    The Yamaha rolls off rapidly from 60 Hz, and is down -10dB at 30 Hz. Yes, this is "usable" but hardly what I'd call a subwoofer response.

    I've played this sub as part of my stage rig, and it is indeed much louder than my (true) subs, but is nowhere close to the low end response. I cannot imagine hauling those monsters around. Huge.

    Anyway, an active crossover is the way to go. The Yamaha has a 90 Hz recommended crossover frequency, but you could probably get away with 100 to 125 Hz, depending on your crossover type. My Rane MX22 is 125 Hz at the lowest point.

    If you want a lot of bottom, get a pair of smaller subs, an active crossover, and put a lot of juice into the subs. Regulate it from the crossover, and you will get tons of bottom.
  6. john turner

    john turner You don't want to do that. Trust me. Staff Member Administrator

    Mar 14, 2000
    atlanta ga
    eric, you are aware that that the send is before the "boost" control, which may be robbing you of some of your pre-master gain, right? i'm with whappo - you need to use the d.i.

    as for the yamaha not being that much of a sub, it works just fine for me, for the low f#, with eq set flat, at about 1/3 the price of "true subs". smaller subs and lots of juice into an active x-over equates to a lot of dough for sub response, which in my experience is unnecessary. as for them being huge, they are also light, and at less than $400 new, they are the best sub deal on the market right now that i've found. besides, using $1000 subs in clubs where the bass response of the room is going to be dicey at best anyway seems to me (who has the money to blow on boutique subs) to be a bit of a waste.

    then again, who am i to argue with specs? :D
  7. Petebass


    Dec 22, 2002
    QLD Australia
    He's right, to send only lows to the sub. But you also mentioned that the 2x10 could use some help in filtering out the lows. Suddenly we're looking at a bi-amping situation.

    If you decide that 2 amps are the go, remember that low end is far more watt-hungry than higher frequencies. Consider running a bigger amp on the sub than what you're running to the 2x10.

    Or if you couldn't be bothered lugging around a second power amp (I wouldn't blame you), you could always un-bridge tha amp run one cab from each side.

    If I were you I'd borrow or hire a crossover and try it out. If it works, buy one.
  8. You aren't aguing with specs. You are arguing with a difference of opinion based on hearing/playing.

    When I wrote the above, I was afraid it would provoke a response, since I know you use this sub. However, my intent was not to irritate you, but to state my personal playing experience of comparing the Yamaha to my subs on the same stage with the same rig.

    I routinely hit 26 Hz at every gig, and I know what it sounds like. The Yamaha audibly doesn't hit it.
  9. john turner

    john turner You don't want to do that. Trust me. Staff Member Administrator

    Mar 14, 2000
    atlanta ga
    hey, i'm not irritated. i'll be the first to say that i'm jonesing for a whappo grande or a bag end elf system. i'm well aware that i'm not getting a clear fundamental on the low F# when i'm playing. i guess my point was that it's a good option for pant flap when money is tight.

    besides, in my experience, clubs don't really do too well on the low low freqs anyway, but my exerience isn't really that extensive on this particular topic. do you have good results with your subs in clubs with the super low freqs? i mean from the audience's point of view?

    i've been meaning to start a conversation on this topic anyway, now's as good a time as any. :)
  10. True fundamentals in a typical bar venue is a mixed bag. When other bassists play my rig, the bottom notes aren't well defined unless I'm 25 feet away from the stage or more. Closer in, they aren't muddy but are more of a feel than an audible note.

    I used an RTA to dial-in the EQ for my regular bar gig, but it produced such a wild EQ pattern that I didn't stick with it. The bar owner HATED the pink noise generator used by the RTA, so I only got to use it once.

    Outdoors, or in large venues is where the big bottom is a huge advantage to the perceived sound. Our regular Sunday gig is outdoors and the big bottom gets the dancing feet moving. It also rattles bottles on the bar and provides cheap thrills to the ladies who sit "just right" in their chairs.

    The 10s, etc, that sound alright in a bar venue seem to sound thin and anemic outside. The big bottom rig sounds like a real bass in these situations. When I move the big rig inside, I wind up boosting the mids and cutting back the bass controls.
  11. BGavin...these are your car audio subs that fill in your huge lows, correct? Most, including me find the SWR IOD a tad "shallow" sounding...just not "deep" enough for me. Interesting that you seem to have almost too much low end? What are these Rockford cabs of yours? Any pics by chance?
  12. Eric Cioe

    Eric Cioe

    Jun 4, 2001
    Missoula, MT
    Actually, I am feeding the 2x10 with 150 watts from my GK head and the 1x18 is getting 700 from a Carvin DCM1000 bridged.

    A crossover is definatley in my near future, I'm getting paid a decent amount for being in the pit band for my school's production of Grease, and I guess I'll use that on a crossover.
  13. I don't have a digital camera, so I'll shoot some on film and post them.

    The Rockfords are the discontinued RFR-2215 model, which is a dual voice coil, true subwoofer. Fs is 20 Hz and each is tuned at 20 Hz in an SBB4 alignment.

    The bottom end is massive. So is the power consumption. I run two of these as a 4-ohm load off the left channel of my PLX 3002. I routinely have the amp flirting with the red clipping LED. I figure each RFR-2215 is getting 450 watts, or 900 for the rated PLX channel at 4 ohms.

    Each cab is 21 x 21 x 31, with a net interior volume of around 5.4 cubic feet or a little more. Bracing is X-Y-Z type with a common nexus. Material is 3/4" MDF and the empty cab weighs a little over 100 pounds. A full sheet of MDF was used (98 pounds), plus lots of screws. The port is 5.875" PVC and front located. Wiring is 12 gauge and Speakon connectors. Two steel recessed handles are installed. Grille is the round Parts Express type that covers just the driver. These are prototypes, so they are not covered. Just beat up.
  14. redneck2wild


    Nov 27, 2002
    Memphis, TN
    If you are looking for a decent crossover at a low price you may want to look at a Rolls SX-21.
    I have been using one for a few months without any problems (replacing a full rackmount DOD unit).
    It runs around $90 new.
    Since the crossover goes down to 50Hz it is ideal for subs. I run mine at anywhere from 75hz to 100hz depending on whether I am using 1 or 2 1x18 cabs.
    Once you split your signal into Lows and Highs, you should see less clipping in your amp.