Bi-Amping My Rig (How well would this work)

5StringFool · #1 01-16-2012, 10:16 AM

I have an idea on how to bi-amp my current setup (so I can get the most out of my speakers) with equipment I already own. I'm just not sure how well this would work.

See what you guys think, I'm new at this.

Thanks. (to the mods.. if I've posted this in the wrong place, lease move it accordingly)

Kitsapbass · #2 01-16-2012, 10:31 AM

What are you running your crossover at? What is the frequency response of each cabinet?

jungleheat · #3 01-16-2012, 10:41 AM

That should work just great (no telling how it will sound, you'll have to see for yourself). Depending on the frequency response and power handling of your 2 cabs, you might want to switch their locations. You'll just have to experiment with different things until you find what sounds best for you.

5StringFool · #4 01-16-2012, 10:42 AM

Was thinking of setting the crossover at 100hz, as far as the Frequency response goes the 18 is 35-1k, the 410 (Fender Pro 410 ST) I'm not sure about... it's not listed in the manual.

The main thing I'm I'm trying to do is get rid of any phase cancellation that's going on due to running both cab's full range. Until I joined this forum I was unaware that such things even happened.

will33 · #5 01-16-2012, 10:56 AM

It would "work", although you'd be carrying around way more speakers than you'd need to carry mids and highs. They'd also beam badly but they do that now so no loss there.

Try setting the crossover low, say 100hz or so just to let the 18 fill in the deep lows the 410 doesn't have, (assuming the 18 does have them). This would allow you to still get a fairly representative bass tone at high volume from the 410 and just let the 18 add a little booty shakin' bass to the mix. It's still a lopsided setup. More overall volume would likely still be achieved running full range but still using the second amp to power the cabs separately so one doesn't hold back the other.

Wouldn't hurt anything to try it, whether the sound is worth the effort is your judgement call. If you decide to go this route, a little 2x8 or 2x10 sealed cab could do the job your 410 is doing. In that case, raise the crossover point to 250-300 hz.

Kitsapbass · #6 01-16-2012, 10:58 AM

Just downloaded the manual for your fender 410, and the frequency response is conspicuously absent. Oh bother.

Well, as far as I would do, I'd set my crossover no higher than 100Hz, I'd actually set it down at like 50-60Hz - YMMV.

How many watts can your power amp put out, and how much can your 18" speaker handle?

will33 · #7 01-16-2012, 11:01 AM

Quote:

Originally Posted by 5StringFool

Was thinking of setting the crossover at 100hz, as far as the Frequency response goes the 18 is 35-1k, the 410 (Fender Pro 410 ST) I'm not sure about... it's not listed in the manual.

The main thing I'm I'm trying to do is get rid of any phase cancellation that's going on due to running both cab's full range. Until I joined this forum I was unaware that such things even happened.

Sounds like you're on the right track as far as getting better sound using what you already have.

will33 · #8 01-16-2012, 11:06 AM

Depending on the size of your poweramp, I might advise against bridging into the 18....potential for speaker damage there.

5StringFool · #9 01-16-2012, 11:13 AM

Quote:

Originally Posted by Kitsapbass

How many watts can your power amp put out, and how much can your 18" speaker handle?

Up to 400 with the SWR, in the setup diagrammed it would be 250, for the 18" it's 700 program, 350 RMs to be powered with a 400 watt amp.

Kitsapbass · #10 01-16-2012, 11:25 AM

Quote:

Originally Posted by 5StringFool

Up to 400 with the SWR, in the setup diagrammed it would be 250, for the 18" it's 700 program, 350 RMs to be powered with a 400 watt amp.

Okay - you almost don't have enough watts to bi-amp effectively. Considering most amps that are capable of running biamp split the power amp ration at least 3 to 1 due to the fact that your ear hears low frequencies quieter at the same wattage. But if you did want to, I'd run the power amp at least at 12 oclock, but the higher you run it, the less headroom you have...so if you slap and pop a lot - this may not be for you.

babebambi · #11 01-16-2012, 11:27 AM

it it the SWR 18" ?

will33 · #12 01-16-2012, 11:29 AM

RMS power is half the story, excursion is the other half. That said, any decent 18 should be able to run 200 watts or better before it starts going non-linear, or in this case, just not getting any louder. That leaves you a little headroom in the amp and everything should work alright. Find a good crossover point and power balance and you'll notice your sound being a good deal clearer than running both fullrange.

5StringFool · #13 01-16-2012, 11:37 AM

Ok then.. I have another option. I was just given a 1987 Carvin Pro Bass II head that has a built in crossover and is setup for bi-amping, it just needs a couple of input jacks replaced, other than that it's in great condition. The head runs 150 watts @ 8 ohms.

If this is as easy a fix as it appears the Carvin head would be a better match for the bi-amp setup, and wouldn't require an outboard crossover. Correct?

will33 · #14 01-16-2012, 11:39 AM

Quote:

Originally Posted by Kitsapbass

Okay - you almost don't have enough watts to bi-amp effectively. Considering most amps that are capable of running biamp split the power amp ration at least 3 to 1 due to the fact that your ear hears low frequencies quieter at the same wattage. But if you did want to, I'd run the power amp at least at 12 oclock, but the higher you run it, the less headroom you have...so if you slap and pop a lot - this may not be for you.

Poweramp dials control input level, not output. Highest headroom is had by running them wideopen and controlling gain earlier in the chain, like at the crossover. Doing it the other way around provides the best signal/noise ratio but not any more headroom.

OP, just do it whichever way sounds the best and stays away from amp clipping. Set your low side to get what output you safely can from your 18 and blend the high side in to achieve whatever tonal balance you're looking for. Your overall volume won't be any louder than you are now, likely maybe a bit less, but the overall quality/clarity of it will improve.

It's the best you can do if a limitation is using only stuff you already own.

Kitsapbass · #15 01-16-2012, 11:40 AM

Sounds right - and the ratio sounds about right as well....

will33 · #16 01-16-2012, 11:44 AM

Quote:

Originally Posted by 5StringFool

Ok then.. I have another option. I was just given a 1987 Carvin Pro Bass II head that has a built in crossover and is setup for bi-amping, it just needs a couple of input jacks replaced, other than that it's in great condition. The head runs 150 watts @ 8 ohms.

If this is as easy a fix as it appears the Carvin head would be a better match for the bi-amp setup, and wouldn't require an outboard crossover. Correct?

Yes, that will do it all in one unit. Won't have quite the power you do with this other setup, but probably enough. I used to play dancehalls with a ProBass II and a 115+210 stack. Sort of a smaller version of your cab setup and didn't lack for volume.

Hopefully it is just jacks. Those units are old enough they're incredibly hard to get serviced anywhere. Sadly, I don't think even Carvin carries a full stock of parts for them anymore.

BassmanPaul · #17 01-16-2012, 12:58 PM

Will, all the Carvin units I have worked on have used standard parts so I see no problem in having a Carvin unit serviced. The newer units with SMT components are a different matter.

Your post #14 is right on the money. The OP will have to listen for signs of distress from the 18" driver. It will not be able to keep up with the tens in efficiency and will not handle the same amount of power. I'd advise stacking the 18" on top of the 4x10 so it can be more easily heard.

5StringFool · #18 01-16-2012, 01:21 PM

I now have the Carvin in my possession and have found the jacks online. They're Switchcraft RNAPC112's and I just ordered 2 of them from Mouser for a whopping $5.54 shipping and all. Hopefully in a few days I'll have the Carvin amp operational.

I am so diggin' the vintage vibe of this amp, here's a pic:

will33 · #19 01-16-2012, 01:31 PM

Quote:

Originally Posted by BassmanPaul

Will, all the Carvin units I have worked on have used standard parts so I see no problem in having a Carvin unit serviced. The newer units with SMT components are a different matter.

Your post #14 is right on the money. The OP will have to listen for signs of distress from the 18" driver. It will not be able to keep up with the tens in efficiency and will not handle the same amount of power. I'd advise stacking the 18" on top of the 4x10 so it can be more easily heard.

That's good to know, I've had some techs tell me they just plain didn't want to mess with them. Maybe the headache of reverse engineering and parts sourcing?

While they're not SMT and you can fairly easily replace individual parts, they are built in sort of a "modular circuit board" mindset. For a while there was some deal going on at Carvin service where they stopped making boards for the redline series and instead of repairing, sending people new bx series amps in some sort of a pro-rated price deal? Don't know the details there.

will33 · #20 01-16-2012, 01:35 PM

Quote:

Originally Posted by 5StringFool

I now have the Carvin in my possession and have found the jacks online. They're Switchcraft RNAPC112's and I just ordered 2 of them from Mouser for a whopping $5.54 shipping and all. Hopefully in a few days I'll have the Carvin amp operational.

I am so diggin' the vintage vibe of this amp, here's a pic:

That's one model older than mine was. Those are cool amps, mine was a 500 watter in more of a typical, "regular" grey carpeted headcase. The control layout looks similair though. I always thought they were nice sounding amps. Felt strong for it's power rating, unlike the redlines that followed.