Distortion/clipping - amp or cab?

[Wil]

Hello! I use a Tech 21 Landmark 300 watt head with a Schroeder 410L. I've noticed when I push the volume to loud practice levels I'm getting distortion but I cant really tell if its the cab or the amp - I have to be very picky with my EQ and roll back the bass quite a bit in order to compete with our drummer and guitarists.

Now, the Schroeder is rated to something like 1200 watts, so it should be able to cope with everything my head can throw at it, right? I've pretty much got the bass control set flat and the treble rolled off a touch, but if I boost the bass at all when I'm running at full tilt I get a horrible buzzy distortion. Do I need more power? How can I tell?

[Moos3h]

Hmmm, I'd have thought it HAS to be the head. That said, the rating on the cab is only a thermal rating, it's entirely possible you could be pushing the speaker cones past their rated Xmax and causing the distortion that way.

Do you know what speakers are fitted?

[Wil]

Not a clue I'm afraid. Might have to whip the grill off at the weekend.

I wish my head had a clip light!

[Moos3h]

Hmmm, yep - roll down the input on your bass a touch and then increase the master volume - does it still distort?

[Wil]

I'll try that tonight at rehearsal. I do tend to run the "drive" control quite high, but that's where all the lovely sansamp grindyness comes from.

[thebassman]

[quote name='Moos3h' post='923781' date='Aug 13 2010, 01:03 PM']Hmmm, yep - roll down the input on your bass a touch and then increase the master volume - does it still distort?[/quote]

+1, you will have to decrease the gain on your Amp untill the clipping light stays off.

Boosting the mids on the amp might help for an apparant volume increase and you might be able to find a frequency range not being filled ny the drummer or Guitards.

good luck

[Wil]

I can compete with mids ok, it's just filling out the bottom end when it seems to strain under my demands. I'll try reducing the input levels tonight and boosting the master, if that doesnt work then I suppose I'll have to try another amp with the cab.

[Mr. Foxen]

Listen to each speaker and see if one is complaining a bit more, if one is a bit duff, it can throw the tuning of the rest out and cause upset. Does the head have a line out? There is a Matamp Quasar power amp in an MDF box at RS that is mine, if you are still there. Run the pre into that, into the cab, you should have a bit more headroom, plus LED indicator to tell you how close to clipping the amp is, it is very neutral voiced, and recently tested so it outputs the full 500w from one side at 4ohm. Should be able to figure if its amp of cab being upset that way.

[Wil]

[quote name='Mr. Foxen' post='923825' date='Aug 13 2010, 01:22 PM']Listen to each speaker and see if one is complaining a bit more, if one is a bit duff, it can throw the tuning of the rest out and cause upset. Does the head have a line out? There is a Matamp Quasar power amp in an MDF box at RS that is mine, if you are still there. Run the pre into that, into the cab, you should have a bit more headroom, plus LED indicator to tell you how close to clipping the amp is, it is very neutral voiced, and recently tested so it outputs the full 500w from one side at 4ohm. Should be able to figure if its amp of cab being upset that way.[/quote]

Yes mate, we're in RS tonight. If you dont mind me doing that, I'd appriciate it, as it should make it pretty clear cut if the cab is indeed the culprit.

The cab sounds fine at lower volumes - I'd imagine a duff speaker would be apparent all the time?

[Bill Fitzmaurice]

[quote name='Wil' post='923764' date='Aug 13 2010, 07:57 AM']Now, the Schroeder is rated to something like 1200 watts, so it should be able to cope with everything my head can throw at it, right?[/quote]Thermal ratings aren't worth diddly. A realistic displacement limited power rating for the Schro would be 300 watts.

[Mr. Foxen]

So at 300w it could be your amp or your cab clipping. Or both. Progress toward a solution.

Have a word with Rich/Steve and have a go with the Aguilar there, that will give you some bottom end.

[Wil]

It's strange really, as I managed to get the bottom end I desired with the same amp and my old 1212L, just not quite at the volume I needed. With this cab I can get the volume but only at the expense of some bottom.

I might be making unreasonable demands of both, mind. The drummer hits like a dinosaur and I'm up against two 100 watts valve amps running through 4x12s. Cranked.

[Mr. Foxen]

Definitely get the Aguilar and Matamp involved, just stand in front of it with open strings bassily feeding back holding a middle finger up to each guitarist. This is how to teach them the meaning of turning down.

Adit: Also, set up a mic and set loads of reverb so you can yell stuff too.

Edited August 13, 2010 by Mr. Foxen

[Wil]

I AM THOR, ARROGANT GUITARISTS! NOW... FEEL MY HAMMER!

[Wil]

Well, many thanks to Oli for letting me use his Matamp power amp at practice tonight. It turns out my cab is fine, and it's my amp that's clipping - I guess due to it being asked to do more than it's power amp can handle. With my Landmark 300 working as the preamp and the Matamp power amp, I had tons of volume, loads of punch, and more low end than I knew what to do with, even in a large practice room.

You know what that means... Power amp GAS. Thanks for the advice all!

[Truckstop]

Mr. Foxen,

I listened to some Caricatures stuff just now and it made my skin crawl it was so evil!
Nicely done!

Truckstop

[Mr. Foxen]

[quote name='Truckstop' post='924491' date='Aug 13 2010, 10:58 PM']Mr. Foxen,

I listened to some Caricatures stuff just now and it made my skin crawl it was so evil!
Nicely done!

Truckstop[/quote]

Cool, cheers, er, buy the record, it is out very soon and available for pre-order. And the guitarist/artist/whatever the guy that masters it is called lives near you.

[bunjy]

[quote name='Truckstop' post='924491' date='Aug 13 2010, 10:58 PM']Mr. Foxen,

I listened to some Caricatures stuff just now and it made my skin crawl it was so evil!
Nicely done!

Truckstop[/quote]

Thanks very much!