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Forums for sound/speakers, or ask here??

Discussion in 'Amps and Cabs [BG]' started by Diggler, Mar 11, 2005.


  1. Diggler

    Diggler

    Mar 3, 2005
    Western PA
    Anyone know of any sound forums where I can get some advice?

    My problem: We need some replacement speakers to finish out our sound system. We have a 400W powered mixer that we're going to use in some small bars. The speakers we have now are 2 15" low end cabinets, and we need some for mids/highs. Before, we had 2-way 15" speakers on top... I'm thinking that 12" speakers might have a little more clarity. Now that's only 100W per speaker... I see quite a few cheap speakers on ebay (Cross Audio comes to mind) that can easily handle that, and they are only about $80 a piece. We are looking for cheap speakers that can get the job done. Local gigs for drunk bar patrons. Has anyone tried budget speakers like these? We'll probably only be playing once a month or so because of jobs, family etc.

    At that price it seems like you almost can't go wrong... even if you buy them and blow the speakers, you could put new Carvin speakers in them and still have less in them than new Carvin cabinets.

    What should I do?
     
  2. Is this a mono 400 watt powered mixer, with two 8 ohm speakers plugged into it? If so, you most likely cannot plug additional speakers in: the resulting impedance would be less than 4 ohms, and your powered mixer probably will not handle the increased load. Check and see, the mixer should say (on the back by the speaker jacks) something like 400 watts, 4 ohm minimum. If it says 2 ohm minimum, you could, but 4 ohm minimum: no go. You would eventually fry your mixer's power amp. If you've successfully done this before, you've been lucky...

    Your best solution IMHO would be just to bite the bullet and buy a good set of full-range speakers. A good set will have more sensitivity, critical for lower-powered power amps.
     
  3. Diggler

    Diggler

    Mar 3, 2005
    Western PA
    This is a mono amp with four outputs, I guess it would be 100 watts per speaker. It also says 200W at 4 Ohms.
     
  4. Just because it has 4 jacks....doesn't mean it can automatically handle 4 speakers. If it says 200 watts at 4 ohms, it isn't a 400 watt mixer (unless it's stereo and therefore two output channels).

    As I said earlier, the total speaker load cannot be lower than 4 ohms or the amp could fry. You could plug in four 16 ohm speakers, since that would equal a 4 ohm load; or two 8 ohm speakers, since that would also equal a 4 ohm load; or you could plug in a single 4 ohm speaker...But if you plug in four 8 ohm speakers, the total speaker load is now 2 ohms, and the amp isn't rated to carry that load.

    I assume you're just running vocals through this mixer, or maybe also an acoustic guitar. You don't have enough power to run bass into the mixer, the result would sound pretty muddy and eat up all your power.

    For vocals and acoustic, forget the 15" low end speakers, just get a good set of 12" two-way speakers, IMHO. Cheap ones won't have good sensitivity--meaning you'll be cranking the mixer's volume all the way up trying to be heard. Better speakers are more sensitive, you get a lot more volume--and clarity. Yamaha makes a good set of 12 inch two-ways that aren't too terribly expensive. JBL also has some good-sounding two-ways. For $400 you can have quality sound...in the long run, it's cheaper to buy what you need now, than to buy something cheap and then pay to upgrade later.

    Also, get a set of speaker stands and raise them off the floor.
     
  5. Diggler

    Diggler

    Mar 3, 2005
    Western PA
    Here's a picture of the outputs... I am trying to find the manual. I think that is 200W at 4Ohms per output.

    [​IMG]
     
  6. illidian

    illidian

    Jul 2, 2004
    Looks like to me like the minimum impedance would be 4 ohms, and power would be 200 watts RMS [at four ohms].

    Check the manual, the picture doesn't tell much.
     
  7. Actually the pic helps. This is indeed a stereo amp, look at the left side, it's labelled L and R.

    The top diagram shows that the two outputs for each channel are in parallel.

    So you can run two 8 ohm speakers per channel. This helps considerably. Now you could keep your low-end 15's and add a mid/high set.

    However, I'd still go for a higher quality set of 12 inch two-ways, as long as they're 8 ohms each. Or ditch the 15's and use a pair of 4 ohm speakers--make sure one is plugged into the top (L) channel and one is plugged into the bottom (R) channel.
     
  8. CrackBass

    CrackBass

    Aug 10, 2004
    huntsville,AL
    do not buy the $80 cabs they will dissapoint you. if you want an idea of what they sound like hook the mixer to a couple of home stereo cabs (cheap ones like off a boom box). they are probably also rated at over 100 watts. see how that sounds and if you like it buy the cabs. also forget running the 15's for lowend cause you dont have a crossover or enough power to even think of running subs. two fullrange 4ohm cabs will be your best option with your current situation. maby some old peaveys or something similar.

    if you're still considering the cabs and thinking "i'll just replace the drivers if i blow them(and you will)". you will also blow the tweeters and fry the cheap crossovers. price out replacing all those components and it doesn't sound like such a good deal. (plus you may have to modify the box to accomodate the new components)
     
  9. Diggler

    Diggler

    Mar 3, 2005
    Western PA
    I talked to the guy who ran this board for us before (when we were starting out) and what we did was use the left and right EQ's for running lower frequencies out of the subs and higher frequenicies out of the tops... instead of Right and Left, it was Lows and Highs, respectively. It's been a long time, we bought bigger stuff and stashed this away, then when we stopped playing sold the bigger stuff.

    I run a Hartke 7000 amp with 2 4x10 GK's on top of 2 15" GK's... usually only end up using half of the stack when we play out (but I have it just in case). So I get 80% of my volume from the amp, I just line my bass out a little bit to fill out the sound. The guitar player's amp is more than loud enough too; he lines out for the same reason. It just sounds better with a little bass and guitar coming through with the voice, seems to even it out some.

    So you guys think I should go with 12" top speakers? I noticed that most 15's seem to have a wider frequency response and seem to include the upper range that the 12's can hit, but do they soak up more wattage, i.e. are they less efficient than the 12's? Also, since this is a 100W per output, what wattage speakers should I be looking for... 150RMS, 200, what? I heard that heavier wattage speakers will sound weak in an amp rated much less than what the speakers are rated for.