Rig questions: QSC PLX 1202 into Genz Benz Uber 4x10

[craig.p]

From a quick look at the filter slopes appearing in the manual, I'm standing by my recommendation of the 50 Hz setting. Those filters appear to be no steeper than 12 dB/octave.

(We cannot select filter knee points based on higher-order filters we do not have at our disposal.)

[BadB]

Originally Posted by damon78

I've been playing bass since I was a kid but have mostly performed professionally on guitar. I'm just getting in to the finer points of bass amplification as I gig more and more on bass.

I had a QSC PLX 1202 for a PA and managed to get a wonderful trade on a Genz Benz uberbass 4x10. I am running it in bridge mono mode currently and I think I should be getting more volume. I have been testing it with the direct out from my Trace Elliot combo since an svp pro I got on ebay was defective and had to go back.

I gigged with it all summer using guitar rig as my preamp (terrible, I know). Now I'm looking into tube pres and am looking at an Alembix f1x, a bbe bmaxt, avalon u5 or ampeg svp pro. I have also been looking at svt pros since they can sometimes be had for not much more than the preamps.

I play in an zimbabwean rumba group, but want something versatile for other gigs as well. I am into more classic tones, reggae and soul, less hifi, Bass and low mid heavy, James Jamerson, Family Man, but I also want the ability to have a variety of sounds for different gigs. I also have an alternative rock gig where I go for brighter, growlier sounds with a p bass.

I play a 1993 American jazz bass deluxe with tape wound strings, a 1990 cp thornton 5 string (neck through 3 bartolinis, aguilar onboard pre) and a 1992 Mexican traditional series p bass with Bill Lawrence p bass pickup.

So, my questions. Which preamp and why? How can I get more volume out of my system? Will I get more volume by adding a second cab and running my power amp in stereo? Different speaker combination? Will two smaller cabs be better a 1x12 and a 2x10 for example? Are the power amp and uberbass a good foundation for my rig? Any other pres I should be considering?

Needless to say all this is on a musicians budget. Thanks in advance for any knowledge you can drop on me.

Here's the specs for the qsc:

http://www.qscaudio.com/products/amps/plx/plx.htm

That cab, with that amp, should be really loud. Get a proper preamp, and make damn sure that you are bridging the amp properly. If you are into classic bass tones and on a budget, a Tech21 Sansamp RBI or RPM would fit the bill nicely.

[BadB]

Originally Posted by agedhorse

Secondly, the likely problem that's responsible for the farting sound (in this specific case) is that the Di out on the amp is likely not able to deliver enough clean drive signal to the power amp.

This. DI is for matching your signal to a mixing board/ recording console.

[damon78]

Originally Posted by BadB

This. DI is for matching your signal to a mixing board/ recording console.

That's what I was thinking.

[BadB]

Genz Benz builds reputable cabinets. When you get your pre/power issue resolved, you'll likely see that your trade for that cab was a good one. BTW, RBI's can be had for around $225-250 on TB.
You never said, but what is the impedance of your cab? That amp will drive an 8 ohm cabinet @ 700W, and a 4 ohm cabinet @ 1200W.

[Zooberwerx]

Originally Posted by BadB

This. DI is for matching your signal to a mixing board/ recording console.

Hmmm...

For the OP: which Trace Elliot combo are you using? I have a TE preamp and the XLR out is not a good choice for "feeding" a slave power amp.

Riis

[damon78]

Originally Posted by agedhorse

Hold on a minute, there's some inaccurate information being stated as fact when in fact it is anything but an incorrect assumption.

The mechanical power rating on the uber 410 is not 500 watts. With any reasonable high pass filtering if is probably closer to 800-900 watts (rms). In fact it was designed specifically to be driven to the maximum rated output of any of our 900 watt (rms) amps and still be within the mechanical limits. The thermal rating is over 1000 watts rms

Secondly, the likely problem that's responsible for the farting sound (in this specific case) is that the Di out on the amp is likely not able to deliver enough clean drive signal to the power amp. Also. Is the limiter engaged on the power amp? It certainly should be.

A 50hz hpf is much higher than necessary, a 40hz 3rd order bw hpf is fine and a 35hz 4th order bw filter is even better and more transparent.

The cab is 4 ohm, so does that mean I can run the 1200 watt amp wide open or close to it?

[damon78]

Thanks for all the knowledge.

The TE combo is a GP7-SM. I'd never heard of it but picked it up cheap.

I am fascinated by the fearful cabs. I looked at the info on his site, but couldn't find the users. Does this stuff show up used here very often?

[Zooberwerx]

Originally Posted by damon78

Thanks for all the knowledge.

The TE combo is a GP7-SM. I'd never heard of it but picked it up cheap.

I am fascinated by the fearful cabs. I looked at the info on his site, but couldn't find the users. Does this stuff show up used here very often?

According to the manual, you should have a "Full Range Line Ouput" on the reverse which is intended for hook-up to a power amplifier. That is if the combo matches the dedicated preamp.

Riis

[agedhorse]

Yes, they are 2nd order filters on the original PLX, I just checked the service manual and threw one of the 1202's I have here on the bench to verify (I was thinking of the LPF in the GX which is third order).

If you plan on driving the cabinet very hard with the 1202 then given the choices the 50Hz would be the better choice. If at more "reasonable" levels than the 30Hz would be fine too. It all depends on the definition of "reasonable" of course

Originally Posted by craig.p

From a quick look at the filter slopes appearing in the manual, I'm standing by my recommendation of the 50 Hz setting. Those filters appear to be no steeper than 12 dB/octave.

(We cannot select filter knee points based on higher-order filters we do not have at our disposal.)