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Question for the Sound Guys

Discussion in 'Amps and Cabs [BG]' started by fleetwood, Jun 22, 2004.


  1. fleetwood

    fleetwood

    Aug 29, 2001
    Swansea UK
    Hi
    Question is.........eg
    If I connect a 100w combo using send and return to another 100w combo, what would be the effect on the total loudness?
    Would it be anything near that of a 200 watt combo?
     
  2. Lockout

    Lockout

    Dec 24, 2002
    Illinois
    What do you mean exactly? Connecting what to what?

    And which combos are you talking about specifically?
     
  3. metron

    metron Fluffy does not agree

    Sep 12, 2003
    Lakewood Colorado
    You cant daisy chain power amplifier sections through an effects loop.
     
  4. But you can daisy chain combos if you come out of the first combo's preamp out and plug that into the poweramp in of the second amp. Don't try to run anything back to the first combo.

    Some bass combos have a high pass filter on their effects loop, so you wouldn't want to use an effects send to connect to the second combo amp (unless you deliberately want the second amp to run mids and highs only....)
     
  5. fleetwood

    fleetwood

    Aug 29, 2001
    Swansea UK
    In a thread I posted titled " Can I Do This?" back on page 6 now, I was told the way to connect two combos was by using the send of the first one connected to the return on the second one. See quote below from Dan Loader

    "The best way to do it, if you can, is to take the "effects loop send" or "line out" of one and send it to the "effects loop in" or "poweramp in" of the second one. That way you don't have to worry about EQ or gain."

    What I'm asking is as you now have two speakers (one in each combo), how does that affect sound output. Do you now have two speakers working at 100 watt each?
     
  6. Lockout

    Lockout

    Dec 24, 2002
    Illinois
    I'm not sure using the FX send would work. If you set the blend to full without anything going into the FX return of that same combo, I don't think you'd hear anything out of it.

    However, if one of your combos has an actual "Line out" or "Preamp out" output, then you should be able to plug that into the FX return of the second combo and play through both at the same time.
     
  7. Use the "line out" if the first combo has it. As I posted before, some combos (for example, my Peavey Databass) have a high-pass filter in the effects send, so you won't get a full-range signal out of that particular send, whereas a "line-out" should be a full-range signal.

    You could come into the return, or poweramp in, depending on the amp where you want to insert the signal .

    As far as volume: IMHO two 100 watt combos would sound louder--but not by much--than a single 200 watt.
     
  8. fleetwood

    fleetwood

    Aug 29, 2001
    Swansea UK
    It does work using the end and return. It works also using the line out. But what I want to know is - am I gaining any power effect. Is it les or more effective than adding an extra cab. And what if I add an extra cab to either combo, What effect on total output would that have.
     
  9. fleetwood

    fleetwood

    Aug 29, 2001
    Swansea UK
    Thanks Nash
    This is what I'm after. The sort of equivalent wattage values.
    If I use an extn cab on the first amp, 100 would become 150. Now add the other 100 combo.....and what are we nearing now? 200 or 250watts. Or doesn't it work like that?
     
  10. Lockout

    Lockout

    Dec 24, 2002
    Illinois
    If you have sound coming out of both, then it's most likely better than just adding an extension cabinet, because you have 100w running through each speaker (200w total). With one combo and an extension cabinet, you'd have ~150w split between two speakers (50w each basically).
     
  11. fleetwood

    fleetwood

    Aug 29, 2001
    Swansea UK
    The reason for the info is that I'm thinking of running my Ashdown EL 130/15 off my GK MB150E.
    This gives me 15" speaker running with the 12". Also, running the 112 cab off the 150 as well gives me two 12" and one 15" speakers.
     
  12. joeybcdt

    joeybcdt

    May 6, 2004
    SE Texas
    Every time you double your speakers or power you get a 3db increase in volume. 3db is not much. You're doubling your speaker AND power for 6db gain in volume.

    Now let's look at adding a cab using a GK 700RB head as an example. The 700RB is rated at 320w @ 8 Ohm and 480 @ 4 Ohm, a difference of 160w or 33%. So if you add an identical cabinet you're increasing your power by 33% (no noticable difference in volume) AND doubling your speaker for a 3db increase in volume.

    So....If you have two identical combos "slaving" one is the easiest way to gain volume. The "Master" amp's preamp will control the "Slave's" power amp. It only takes one cable to hook up the "Slave". If you use two, something's gonna burn.

    My question is if you can afford two decent combos why didn't you buy one with sufficient power?

    Joey
     
  13. fleetwood

    fleetwood

    Aug 29, 2001
    Swansea UK
    Good question! The short answer is I've had a back problem over the last two years caused by trapped nerves. I had an Ashdown ABM 500/15 combo which I used for larger gigs and the EL 130/15 for smaller venues. The ABM became far too heavy for my back so ended up using mainly the EL. In fact the EL managed very well in the size of venue we usually play in. However, it was still a bit too much to carry (44lbs) in some situations. I was introduced to the GK MB150E (24lbs) and I was very pleased with its performance and weight so I traded the ABM in for the GK. The GK MB150 easily out performs the EL, even without the additional 12" speaker.
    I'm interested in what may be any increase in output from running the two combos together just in case I need some extra sometime.
     
  14. joeybcdt

    joeybcdt

    May 6, 2004
    SE Texas
    How about a GK 1001RB and one or two 1-12 cabs?
     
  15. fleetwood

    fleetwood

    Aug 29, 2001
    Swansea UK
    I would loose too much money changing again at this stage. I lost money with the ABM trade in. The MB 150E as yet seems as if it's going to cope with most situations. And all for one small box of 24lbs. It's just maybe the odd one occasion I may need something more. We play mainly middle of the road, swing, country, rock & roll, rock, latin, ballads with male vocal, female vocal/keyboard, sax/clarinet/vocals, drums and bass.
     
  16. fleetwood

    fleetwood

    Aug 29, 2001
    Swansea UK
    Oh and the drummer isn't miked, I'm on my own and the rest go through the PA,
     
  17. redneck2wild

    redneck2wild

    Nov 27, 2002
    Memphis, TN
    Are you trying to get more volume by running 2 combos?

    Does one Combo gives you the tone you are looking for over the other or can you get what you are trying to get from either?

    There are several ways to get additional volume by using two combos.

    You could use a "Y" cable to split your signal between the combos.
    Some combos have 2 inputs where the 2nd can be used to loop to the input of another combo.
    If either combo has a line out , you can use that one to chain to the input of the other combo (NEVER, NEVER run the SPEAKER OUT to the input of a combo).

    For the most volume, you could try using one amp to produce the Lows and the other amp to produce the Mids/Highs.
    Lets say one combo has a line out.
    Run your Bass into combo 1 with a line out. On combo 1 cut the Lows. By cutting the lows, you can get more volume out of combo 1. Run a line from the line out into the input of combo 2. On combo 2, cut the Mids and Highs (all the way down) and boost the lows. By cutting the Mids/Highs from the 2nd combo, you can get punchier lows. You will need to play with the volume on both combos to balance the sound.