How high and or low can you go?

March 10, 2009 1:23 PM

Help me set up my bass rig.

I've got a nemesis 2x10 combo and a peavey 1x15. I'd let to set these up in some kind of configuration so that only highs get sent to the 2x10 and lows get sent to the 1x15.

But I've never messed with anything like this before.

Where should I start?

posted by tylerfulltilt to media & arts (20 comments total)

Go to gearslutz.com if you haven't already. It really is the best place for this type of question.
posted by fantasticninety at 1:45 PM on March 10

You'll need a crossover and a sep. amp head for the 1x15. Split the output from the preamp in the nemesis, and send it to the crossover. Send the low to the other amp head and the peavy, and send the highs back to the nemesis.

I'd get something with some pretty good kick to it, for the 15- say 500watt?
posted by jenkinsEar at 2:01 PM on March 10

The 1x15 is a combo as well, should have mentioned that. Yeah it's a 500 watt combo, The 2x10 is 200.

WTF is a crossover?
posted by tylerfulltilt at 2:03 PM on March 10

a crossover splits the audio signal into a high and a low frequency signal. Here's the wikipedia link.

Here's a cheap one. I'd suggest trying one out with your gear; listen for any noise that it injects. Your local music store should have something suitable. If you're doing pro stuff, I'd recommend rackmount gear and an active crossover, otherwise you can probably get by with something cheaper and passive.
posted by jenkinsEar at 2:11 PM on March 10 [1 favorite]

Rather than dicking around with crossovers, why not just get a signal splitter and adjust the EQ on both amps?
posted by rhizome at 2:38 PM on March 10

Signal Splitter would be a bad idea rhizome. Splitting the signal and playing with an EQ will muddy the signal on both ends (EQ's are not perfect at removing signal areas). If sound quality is .. at all important.. that's a bad idea.
posted by frwagon at 3:04 PM on March 10

I'm not familiar with any Peavey 1x15 combos that have more than one power amplifier. This means that you are effectively stuck with the same signal going to both cabs as long as you are using the Peavey as your only source of power.

A crossover has the ability to split one signal into two separate signals, one high frequency and one low frequency (fancier ones offer more options for splitting signals). However, crossovers are generally used *before* your instrument's signal is amplified and sent out to a speaker cabinet. There are crossovers that exist for splitting an amplified signal, but they tend to be either finicky or expensive. Your Nemesis combo has a crossover that dumps some of the high signal into it's tweeter, and if you've ever heard of someone "blowing" a tweeter it's because their crossover was not up to what they were asking.

There are a number of ways to accomplish what you'd like, but most of the approaches I would recommend would involve adding another amplifier. Your simplest solution would be to get an A/B box (to duplicate your signal) and a second amplifier to power your 2x10. Cut the lows on the 2x10's amplifier, the highs on a Peavey (not that you're getting a lot of those out of that cab anyway) and voila--a bi-amped system. This approach would also let you apply effects to high and low signals separately.

The crossover's mentioned above will do this as well, but you're still looking at a second amplifier. There are numerous ways to go about this, though. I would suggest checking out and asking your question there--they're notorious gearheads (and sometimes gear snobs, but that's the nature of internet music forums).
posted by Benjy at 3:06 PM on March 10

Benjy, each amp is a combo. The 2x10 has 200w, the 1x15 has 500.
posted by jenkinsEar at 3:26 PM on March 10

*FACEPALM* Then an A/B box would be the easiest approach.
posted by Benjy at 3:43 PM on March 10

Or you could just get an amp with a built in cross-over. Gallien-Krueger used to make them with separate outs for the high/low outs, with a control for the sweep. I believe Ampeg did, as well.
posted by peewinkle at 5:27 PM on March 10

I'm not sure about an A/B box, for the reasons that frwagon mentioned. Plus, it sounds like the only A/B boxes that don't dick with your tone somehow are pretty expensive
posted by tylerfulltilt at 6:10 PM on March 10

There are two types of crossover, active and passive. Passive is between the amp and the speaker, so one amp can drive two speakers, each with it's own crossover. Active crossovers are before the amp, so you would need two amps (which you do have.)

The best active crossovers for the price are Rane, in my experience. On ebay, you might spend 2 or 3 hundred. They come in a lot of variations, so you'd need to find someone knowledgeable to help you with that. Passive crossovers? I'd use a parametric equalizer to find the crossover points I wanted, and then look up the numbers for the parts to build one like I wanted. Again, have a friend who is an electrical engineer is like having a lawyer for a friend, well worth the trouble.

Most crossovers are for dividing tweeters / mids / bass. Splitting bass into low and extra low isn't the usual configuration, the Rane can probably do it. Advanced practitioners can alter some parts in the Rane to change the cutoffs. Again, be NICE to those electrical engineers, invite them to performances, they don't get many chances to meet girls.
posted by StickyCarpet at 7:41 PM on March 10

Something like this will do the job for $4.89. Plug it into your bass's output and take a lead to each amp. EQ each amp according to taste. The 10s will favour the mids and highs, the 15 will give you the thump.

Just dial it in. Simple.
posted by Wolof at 5:45 AM on March 11

There are two types of crossover, active and passive. Passive is between the amp and the speaker, so one amp can drive two speakers, each with it's own crossover. Active crossovers are before the amp, so you would need two amps (which you do have.)

Not to be too pedantic but active vs. passive refers to whether the crossover contains active or passive components (eg transistors/opamps vs. just resistors/caps/inductors). Active crossovers require some power source and they have the advantage of having a potentially steeper crossover slope without signal loss compared to passive. But passive crossovers can certainly be placed before the amplifier.

Back on topic, some Peavey amps (maybe just heads only, I'm not sure) do have internal crossovers, so you may not need anything beyond an extra cord. Can you link to the amplifiers you have, or the product manual? Peavey's site should have the manual available for just about anything they've ever made.
posted by 6550 at 6:46 AM on March 11

I google'd up an instruction manual for my combo 115 and it does contain an active crossover. The manual says I should run a small patch cable from the low out to the power amp in, and then run a cord from the high out to the 2x15 combo.

does this sound right?
posted by tylerfulltilt at 12:43 PM on March 11

Make that "... a cord from the high to the 2x10 combo."
posted by tylerfulltilt at 2:33 PM on March 11

Yep, that sounds just right. Run the high out to the power amp in of the 2x10 combo, if available.
posted by 6550 at 8:10 PM on March 11

If I ran the high out to the normal instrument in on the 2x10 combo would that do anything bad?

cuz that's what I did.
posted by tylerfulltilt at 9:22 AM on March 12

you're sending it thru 2 preamps, which will probably not break anything, but will give you lots of gain and distortion- probably sound like crap.

Your 2x10 should have an effects loop or a preamp out / poweramp in. Run the high signal into the poweramp in or effects loop in.

Amps have two stages- a preamp that brings up the (very weak) signal from your instrument and a power amp that pops the signal up into something that can really move the speakers. Amps will usually offer an effects loop that lets you plug in gear between the preamp and poweramp. You'll want to bypass the second amp's preamp and go right into the power amp stage.

If your system is a nemesis RS 210, it has an effects loop. Try plugging the out from the peavy's high end into the effects loop in.
posted by jenkinsEar at 11:43 AM on March 12

Jenkins I do believe you have nailed it. I was having a really hard time getting the sound from the 2x10 to not be overly loud and distorted.

When I next have a chance to go to the rehearsal space I'll do it up your way.

Thanks for all the help
posted by tylerfulltilt at 4:40 PM on March 12