Clipping?

[Gadolinium]

I am officially confused...

Originally, I thought clipping was caused because the amplifier had a higher output than the speakers could handle. However, now Im not sure, because I recently heard that clipping was caused when the speakers had too much power for the amplifier to supply.

Which way round is it? Is it caused by too much power in the speakers or the amplifier?

Related to this is my amp. It clips when the volume knob is turned to about 12 o'clock, which sucks. The head (PV nitrobass) is rated 300watts at 4 Ohms, whilst my cab (PV 410TVX) is rated 350watts (4 Ohms). Is the problem because I have too much power in the amplifier, or too much power in the cab?

 

[OriginalCrash]

As I understand it, clipping has nothing to do with speakers (not that you can't get speakers to distort, though). Clipping is when the signal going to the amp is too strong. The peaks and valleys of that signal then get "clipped" off, resulting in a distortion of the original sound/signal.

Brian

 

[bongomania]

Clipping occurs any time ANY component anywhere in your rig receives a signal that is higher in amplitude than it is designed to handle. It can be a discrete component like a transistor, or a complex circuit involving many dynamically-related components, or a mechanical component like a speaker, it doesn't matter.

Every component has a maximum input it can handle; exceed that maximum, you get clipping.

Edit: OP, you need to search on the terms "underpowering" and "overpowering". Many, many pages of debate to read.

 

[Crockettnj]

I am officially confused...

I think part of the problem is that you are misapplying the term "power".

... I recently heard that clipping was caused when the speakers had too much power for the amplifier to supply....


... Is it caused by too much power in the speakers or the amplifier?...

...Is the problem because I have too much power in the amplifier, or too much power in the cab?...

You are implying that your speakers AND your amplifier have power in them. In reality, the speakers have no "power" in them. The amp is supplied energy (from the wall socket) and therefore can do work , move something, such as the voice coil of the speaker. The amount of work done in a given amount of time is the power of the amplifier. Watts are one unit describing power.

So when you read the back of your amp, it may have a power rating. This is the power your amp can supply to something. A speaker, for instance. (depending upon the way it was measured, and the rating system, the numbers can vary and be misleading. Others with a better understanding will hopefully chime in, or you can do a little search on TB.)

When you read the back of your speaker cabinet, that "wattage" or power rating is'nt what it can supply. Speakers supply nothing. INstead, it is the power it can handle being supplied to it. Again, the amp is the thing doing the work, not the cab.
(this, too can lead to pages of confusion as well, since the rating that the speaker can handle may be a rating of music signal, or a pure sine wave, or until the speaker coil melts, or until the speaker physically breaks, or the short term handling, or the long term handling, or some other permutation. )

I may not have answered your question, but realigning your thinking and learning the correct application of the "vocab" terms will ultimately help you to understand the answer that is posted.

 

[billfitzmaurice]

Related to this is my amp. It clips when the volume knob is turned to about 12 o'clock, which sucks. The head (PV nitrobass) is rated 300watts at 4 Ohms, whilst my cab (PV 410TVX) is rated 350watts (4 Ohms). Is the problem because I have too much power in the amplifier, or too much power in the cab?

The clipping lamp indicates that you have the volume knob turned up too high. Turn it down. It has nothing to do with the speakers.

 

[Transverz]

The clipping lamp indicates that you have the volume knob turned up too high. Turn it down. It has nothing to do with the speakers.

I don't think this is too off topic, but what about in relation to a preamp? For example, I had an Ampeg SVP-Pro. I'd plug my MM Sterling into jack and pad it. I'd have the gain at 12:00 and the volume at 12:00 with no extreme EQ settings. It was going into a QSC RMX 850. Doesn't matter what cab I hooked it up to, not only was the input clip light lit up most of the time which is not so bad I guess, but the QSC's clip light would light up way too often for my taste. A couple of times, it shut down on me.

What's up with this? Was the preamp overdriving the QSC's input? I thought 12:00 on the master and gain was a bit too low to think I was taxing the QSC. I guess what I'm asking is, was the only problem with that equation was that I didn't have a powerful enough amp to do what I wanted? And if so, then even if I went to a more powerful amp that may or may not get me the volume I want, 12:00 is all I can get out of the master volume of the preamp without clipping the poweramp?

 

[billfitzmaurice]

12:00 is all I can get out of the master volume of the preamp without clipping the poweramp?

The problem with preamp clip lamps lies in knowing where they're measuring the clipping. It may be after the first gain stage, it may be at the output of the pre. That you'll have to find out from the manufacturer. What the clip lamp tells you is that at the point where it measures levels you have reached the limit of what you can get while keeping the signal clean. The QSC clip lamp tells you that you've reached the point of where it will deliver clean output. In both cases you can run higher, but you are clipping the signal, and run the risk of toasting tweeters, if you have them.
As for where the knobs are pointing at, it matters not, that's no indication of how much power you're putting out. The only definitive thing having a knob set at 12:00 tells you is that it's higher than 11:00 and lower than 1:00.
90% of the time if you've got an amp of reasonable size, say 200 watts or more at an 8 ohm load rating, and it won't go loud enough, your speakers are inadequate, usually in quantity rather than quality.

 

[Bob Lee (QSC)]

I don't think this is too off topic, but what about in relation to a preamp? For example, I had an Ampeg SVP-Pro. I'd plug my MM Sterling into jack and pad it. I'd have the gain at 12:00 and the volume at 12:00 with no extreme EQ settings. It was going into a QSC RMX 850. Doesn't matter what cab I hooked it up to, not only was the input clip light lit up most of the time which is not so bad I guess, but the QSC's clip light would light up way too often for my taste. A couple of times, it shut down on me.

What's up with this? Was the preamp overdriving the QSC's input? I thought 12:00 on the master and gain was a bit too low to think I was taxing the QSC. I guess what I'm asking is, was the only problem with that equation was that I didn't have a powerful enough amp to do what I wanted? And if so, then even if I went to a more powerful amp that may or may not get me the volume I want, 12:00 is all I can get out of the master volume of the preamp without clipping the poweramp?

The RMX850 doesn't have an input clip LED, but it has an output clip LED. You didn't mention where you have the amp's gain control set. If you have it turned way up, it won't take a large input signal to drive it to the point of clipping.

 

[Transverz]

The RMX850 doesn't have an input clip LED, but it has an output clip LED. You didn't mention where you have the amp's gain control set. If you have it turned way up, it won't take a large input signal to drive it to the point of clipping.

Yes, that is a good point. I had the gain control at about 3:00, almost all the way. If I did turn it closer or at 12:00, then would I have been able to turn the preamp's master volume/gain higher? And if so, would I get the same results (ie volume) as I did when I had QSC's gain control at 3:00, or would being able to turn up the preamp result in a higher volume without setting off the QSC's output clip LED?

Thanks...

 

[Bob Lee (QSC)]

You could turn the amp down and the preamp up. But the amp will still clip at the same output voltage, so it won't be any louder at that point than it was before.

Can you tell us anything about the cabinet? Are you running it on just one channel of the amp?

 

[Transverz]

When I had my SVP-Pro + QSC RMX 850 rig, it usually went in my 2x10 + 1x15 Mesa Diesel cabs (stereo) or my Mesa Diesel Powerhouse 1000 bridged @ 4 ohms. At practice, the clip light on the QSC wouldn't come on too much though in the months before I sold that rig it seemed to come on more often. It would mostly be a problem at shows as the preamp usually would have to turned up past 12:00.

I'm pretty sure I was trying to attain a volume that the RMX 850 wasn't intended for. So that's my fault for not picking up a bigger PLX or something. But I mostly felt the whole time I owned that rig that the preamp was putting out way too hot of a signal for the QSC. Like the preamp signal was so hot, I couldn't use all it was capable of. Probably my fault too. I dunno.

 

[Gadolinium]

Okay, I guess what i meant was, which part of my amp is clipping? Is it the head, or the cab, or both, or cant you tell?

If i was to buy another cab, which Ive planned to do for ages, then my amp would put out 45o watts at 2 Ohms. The speakers would have a combined power rating of 750 watts. Would that clip the amp?

 

[bongomania]

We can't tell without knowing your settings on every component including any pedals and the onboard pre of your bass.

Aside from that, please read carefully posts # 3, 4, and 5. Then re-read them. Speakers cannot clip an amp.

 

[Transverz]

Yes, speakers themselves can't clip amps. But the way I understand it, if speakers are inefficient enough or don't have low enough frequencies to handle the job, the user will try more extreme settings to try and get what they want, thereby pushing the amp beyond its limits and result in making it clip, farting, etc...right? Of course, this is user error and not the speaker's fault. The speakers can only do what they were made to do. Correct me if I'm wrong please.

 

[jbotz9]

i think u are right transverz. im sort of have a similar problem. i have a trace elliot v6 head (4 ohms) with 2 cabs (4x12 and 2x15 running at 8 ohms each). my gain is set around 2 o'clock and my master volume is set around 11 o'clock. sometimes when i raise the gain or master volume too rapidly itll clip for a bit but itll go away. even when i raise the volume on my jbass too rapidly ill hear the clipping. its no big deal as it goes away but worries me nonetheless. i think i have enough headroom and my speakers are not the problem. i think my head is pretty powerful and the volume shouldnt be handled rapidly. check to c if thats ur problem gadolinium because it is mine...

 

[bongomania]

Yes, speakers themselves can't clip amps. But the way I understand it, if speakers are inefficient enough or don't have low enough frequencies to handle the job, the user will try more extreme settings to try and get what they want, thereby pushing the amp beyond its limits and result in making it clip, farting, etc...right? Of course, this is user error and not the speaker's fault. The speakers can only do what they were made to do. Correct me if I'm wrong please.

That all sounds perfectly correct to me. A lot of the time when someone asks here why their speaker or amp is distorting, it turns out they have a small or inefficient cab and they're cranking the bass EQ on their amp to try to get more out of it.

Also, the reason I mentioned settings on preamps and pedals etc. is because cranking the gain or an extreme EQ setting before the amp can cause clipping anywhere further along the signal path.

 

[Xed32]

Turn the gain down, Turn the master up. My amp kept clipping when my gain and drive were up on my svp-pro. Turned down my gain, turned down my drive, turned up the master and turned up the volume on my QSC. HAve to balance and juggle gain/volume knobs. Kinda annoying. Wish I had a Line out Volume control cause after I balance all my volumes for my speakers to get loud without amp clipping, the sound man tells me he needs more volume into the PA...more balancing.....