Crown & Sansamp - clipping?

[Downunderwonder]

Read the manuals, know what your cabs are capable of delivering, hook up and play.

If the amp clips, turn down the pre out. If the speakers distort, turn the amp down and/or reduce low end eq. If that doesn't solve it there is something amiss in the gear itself.

 

[BurningSkies]

"Well, there's your problem right there" - my mechanic.

All other issues are moot until you correct the basic set-up.

Riis

I agree. If you're bridging with an amp that needs a special cable and you don't have that cable, you're not bridging.

As someone who plays a fEARful 15/15/6 setup and bridges a 3Kw amp, if you're not getting 'impressive volume' clean, you've got some other problems not related to your cabs (assuming they're correct).

 

[Downunderwonder]

A single channel driving a 1515/66 should blow away the drumset no problem.

 

[tech21nyc]

Thank you sir. I could definitely tell by ear that the "mid" control was somehow affecting distortion. I have ran the preamp with a low "drive" and "blend" setting and the pad disengaged...but even with the level up and more generous EQ settings, it seems that it lacks the "punch" that I crave and the headroom that I need. The power amp seems to clip at even less volume than my other setting (with the pad engaged and drive increased). Mind you, "less volume" to me is probably normal volume for most people but we have 3 guitar players with tube amps and everyone (including myself) is using a germanium fuzz pedal.

I figure it all has to do with the input sensitivity in the Crown and the high voltage properties of the Sansamp assaulting it. I am curious if the output voltage is increased a lot with more added to the EQ and less "level" and/or "drive" or vice versa? I used to have a QSC MX1500a and it did not have this issue. I could crank the Sansamp a lot more into that amp. Too bad it blew up during a gig (in between songs and not while being pushed).



I might have used the wrong terms in wrong manner. When I say "clipping," I am not necessarily referring to distortion...I am referring to the CLIP light on the Crown power amp.

It seems like you are in a very loud situation. How are you running the power amp? Bridged mono, stereo etc. From the specs I read from Ampeg that cab is either two stereo 8 ohm inputs or one 4 ohm mono input rated at 800 watts with a 100dB sensitivity. Running in stereo you get 600 watts and in mono 525 watts. You can bridge at 4 ohms and get 1550 watts but you would probably damage the speakers if you aren't really careful.

I'm also confused about "headroom" and "punch", is that with the fuzz turned on? In general those two terms would mean you have power to spare. When you start using distortion a byproduct of that is compression and heavy compression will diminish the attack and punch. A fuzz will really limit your dynamics.

Are the 3 guitarists using stacks. Mind you that the difference between 300 and 600 watts is 3dB which is not that great of a jump. To double the power of 300 watts you would need to go to 3000 watts and also more speakers.

Without being there I can only speculate, but it seems like you may be trying to get more volume via the power amp when you may need to add an additional cab. If the guitarists are using three 412 cabs which is twelve 12" speakers, your 810's will be no match. I really think adding another cab is the solution or turning the whole band down.

 

[subexpression]

BurningSkies, exactly.

Required:
Two Neutrik NL4FC (4-pole) connectors
10 to 20 AWG cable (for short speaker connections)

Wire the "amp" end +1 (positive) and +2 (negative).
Wire the "cabinet" end +1 (positive) and -1 (negative).

If you're using a 2-pole Speakon, your cabinets are not receiving the 4ohm bridge-mono signal even if your amp is bridged.

I learned this one a while ago when these kind fellows helped me out

Make sure you use a Sharpie (or gaff tape) to mark the AMP end of your cable, because it has to be the end wired to the +1/+2 poles.

Happy bridging!

 

[captainbeyond]

It seems like you are in a very loud situation. How are you running the power amp? Bridged mono, stereo etc. From the specs I read from Ampeg that cab is either two stereo 8 ohm inputs or one 4 ohm mono input rated at 800 watts with a 100dB sensitivity. Running in stereo you get 600 watts and in mono 525 watts. You can bridge at 4 ohms and get 1550 watts but you would probably damage the speakers if you aren't really careful.

I'm also confused about "headroom" and "punch", is that with the fuzz turned on? In general those two terms would mean you have power to spare. When you start using distortion a byproduct of that is compression and heavy compression will diminish the attack and punch. A fuzz will really limit your dynamics.

Are the 3 guitarists using stacks. Mind you that the difference between 300 and 600 watts is 3dB which is not that great of a jump. To double the power of 300 watts you would need to go to 3000 watts and also more speakers.

Without being there I can only speculate, but it seems like you may be trying to get more volume via the power amp when you may need to add an additional cab. If the guitarists are using three 412 cabs which is twelve 12" speakers, your 810's will be no match. I really think adding another cab is the solution or turning the whole band down.

Bridged mono into the 4 ohm mono input on the 8x10. Yes I know it is excessive, but in my experience, these class D XLS amps don't sound like a true 1550 watts. The peak rating of the Ampeg is 1600 watts and from what I read on here, several people claim that it is an okay match. I am very careful, which is why I addressed my concerns here in the first place. I want maximum volume without clipping the amp or blowing my cab. LOL.

I don't play with my fuzz on all the time. All my queries are regarding my clean tone. No effects. Although using my fuzz makes it easier though as I don't have to worry about hard peaks and lows in the volume. I usually set the fuzz to slightly boost the volume level of my clean signal, as well as the added harmonics/frequencies.

The guitarists cabs total up to 7 12"s. One guy is gonna replace his 1x12 with a 2x12 soon so pretty much 8 12"s in the near future. I have 2 8x10s. One is usually enough for a gig but in practice, I daisy chain them both at bridged mono. I have tried running them separately stereo with the amp set to Y in the input, but the volume just isn't there at 525 watts per cab. I will try it out again this weekend.

I have a Sunn 2x15 cab that needs to be loaded. That would probably solve my problems! LOL

 

[subexpression]

After starting this thread I've learned quite a bit about the Pre+PA solution and how to make it work.

My chain:
Passive Bartolini J's -> modded Boss CS3 -> Sansamp RPM -> Crown XLS 2500 bridged 2400W@4ohms -> two daisy-chained Hartke HX410 cabs

The two 8ohm HX410's (4 ohms when daisy chained) together are approx. 2000W RMS

The Crown XLS 2500 in 4 ohm bridge-mono delivers 2400W.
I'm running it two different ways:
1. amp CH1 attenuator at 100%; adjusting pre output for volume
2. pre output at 100%; adjusting amp CH1 attenuator for volume

These two methods affect the sound and it's up to you how you want to run your rig.

It seems that the Boss CS3 (or any compressor for that matter) is critical. It keeps the transient spikes from pushing the amp too hard. Turning the attack slightly down slows down the compression—softening the spikes and at the same time keeps it from squashing the signal.

Setting a low-pass filter (easy to do with the Crown XLS) will also divert wasted watts to audible frequencies instead of dumping them into inefficient cone motoring.

Plus, the lower range of a 5-string bass doesn't require the amp to produce those specific frequencies. The illusion of the low 'B' string can be replicated in higher harmonics. The result is that the listener mentally fills in the gaps and hears a 'B' (~30Hz) even if the low-pass filter slopes off at 50Hz. The hum-n bra-n do-s th-s ver- w-ll. The end result is louder, more-efficient speakers.

And yes, my rig might seem a bit extreme, but for our style and genre, those extra few dB's are a necessity for matched stage volume with the guitar and drums.

My next project is to use my old Hartke HX115 as a reinforcing sub since the 810's are covering the upper frequencies. My plan: use one of the Sansamp's outs, xover, run into a 500W amp @8ohms into the HX115. I'll use it like salt & pepper...nothing ridiculous. Although, many would say my rig is over the top already.

 

[Downunderwonder]

One other thing, extracting the last few dB of loudness with hpf protection then places you in danger of thermal failure. If you sense you're losing volume over the gig you are in the initial stage of said meltdown.

 

[subexpression]

Downunderwonder, I said 'extra few dB's', not last few. I have plenty of headroom with my rig and everything is running cool & efficient. With my amp's CH1 attenuator at about 11 o'clock, I have plenty of headroom and could afford to push it even more, but it's not necessary. All's well.