How much power is REALLY needed on stage?

[michael_g]

My rig with a 300W amp and two cabs (1x15 and 2x10) served me well in the last 20 years. Independently from any stage size that was enough power for me. However a good monitoring and a good PA is required.

 

[Bass_Pounder]

So, roughly, 2x15 at 180w 4ohm would be about 4 times as loud as 1x15 at 120w 8 ohm?

Not even close...............


Just to be twice as loud, you need 10X the power


Your example would be more like a difference of +3db. You'll notice a difference, but not alot.

 

[JimmyM]

Well Pat, I suppose I could be wrong. I got it from this textbook, you should get in touch with these people and tell them you consider them and all the expirence they have is just a myth.

http://www.amazon.com/Live-Sound-Reinforcement-Mix-Audio/dp/0918371074

Sure you like lots of headroom, I'm sure everyone would love 10,000 watts of spare overhead ready to unleash on the unsuspecting masses but the reality is that simply isn't required regardless of your personal preferances.

Real world sound guys hate people like you because that overhead you covet so much is just you sabotaging the mix and giving the sound crew headaches because your constantly creeping up in the mix whenever you feel you are not loud enough.

Changing ohm's of course is going to make a difference. Adding speakers changes the power requirments for sure but not without changing the ohm's so your doing the "My apple tastes different that your orange and I like my apple better" thing. Try the expiriment WITHOUT reducing the ohm's and see what you get.

-eSmith.

i have read so much misinformation in books and articles by people who should know better that it's not even funny.

 

[bassmanjla]

I use a TC RH450. I play in LA, so basically I use backlined cab's almost exclusively. Sometimes they are 8-10's, sometimes they're not. Hell sometimes, I'm just DI'd out the back and only hearing myself through the wedges.

But I don't mind that. I like a good wedge mix. When I have one, I don't really feel like I need a cab at all. So sometimes I start to wonder, "why don't I just use a preamp DI and screw this other sh**T?"

Where I really need to volume however, is in small (like 100 people room clubs, or rehearsal spaces) environments where the presence of the drums is MUCH more overwhelming. and the entire sonic space is FAR more saturated.

Even in the worst case scenarios, the master on my RH450 is RARELY above 4. and generally hovers around 3. and the digital volume preset, is dropped all the way to one so the boards don't go crazy (the RH450 seems to have a pretty loud DI), and my EQ isn't really boosted much, just upper or lower mids about 3 or 4 clicks depending on the bass, the cab and the room.

I've learned from others and found out for myself, that a lot of your ability to cut through a mix is guided by your fingers. If using a pick, your attack is going to be much more penetrating. but if you are a finger player, you have to make sure that your striking the string fully and not just "petting them", as someone once advised me. Where you are striking the strings makes larger difference in the tone, and penetration of your attack. BE sure to take into consideration, the location and tonality of your pickups, the tonality of the notes you are playing and the tightness of the string where you are striking it, when you deciding how hard, to attack the strings.

anyways, thats my opinion.

 

[mellowyellow]

My thoughts about adding more drivers doesn't result in a linear equation of "loudness". An 4X10 4ohm cab rated at 1000w but driven by a head outputting 500w at 4ohms is good and loud. By to make it even louder you have to double its input. You can buy an very expensive new amp or bridge the really nice amp you already own (But if you own that one you would already be doing that.) Going from 120w (1x15@8ohm) to 180w (2x15@4ohm) will be louder, but primarily it's because there's another 15 moving air. It's not 4x louder. A better setup would have 275-300 driving that 15 @8ohm, and 500-600 @4ohm by adding another.

 

[Bass_Pounder]

My thoughts about adding more drivers doesn't result in a linear equation of "loudness". An 4X10 4ohm cab rated at 1000w but driven by a head outputting 500w at 4ohms is good and loud. By to make it even louder you have to double its input.

Nope...................

1,000 watt rating is thermal limit, not mechanical. Most speakers hit their mechanical limits at half their thermal ratings.

Throwing "more power" at 1,000 watt 4X10 already being powered by a 500 watt amp will get you nowhere fast.

The key is MORE SPEAKERS with the appropriate amount of power.

 

[seanm]

I have a 500W combo with an extension cab. For me, that is good for 100% of my gigs, which generally fall into two types:

1) Vocal only PA. Since the drums don't go through the PA I don't need to be any louder than the drums. If I can't be heard... the drums can't be heard.... and that is a *band* problem. i.e. One or more of the other band members are too loud. I refuse to get into volume wars. If the drums can't be heard, the mix is already off... I am not going to make it worse.

2) Full PA. In this case, my amp is just a monitor. I have never needed more than 500W (knocks on wood).

One caveat to this: once I tried out an ACME B210 8 ohm cab at practice where I normally used only the 1x12 combo. I could not get enough volume, so cab sensitivity matters.

 

[elavate7]

Lemmy uses a 100w head pushing a **** ton of speakers and Motorhead is considered one of the loudest bands on the planet.

I think that says a lot right there.

well, if i was running a 412+415, i would be using 50w lol

 

[mellowyellow]

That's correct. That extra 3db you would get by doubling power would only gain extra headroom you probably don't need if you already have 500 clean w. Moving more air with more speakers with adequate power IS the key. The small gig rig with enough amp to add another cab is the avg. answer for most players and today's systems are very good. The advanced and advancing pros have the needs and means for multiple specific rigs for every venue.

 

[SactoBass]

Nope...................

1,000 watt rating is thermal limit, not mechanical. Most speakers hit their mechanical limits at half their thermal ratings.

Throwing "more power" at 1,000 watt 4X10 already being powered by a 500 watt amp will get you nowhere fast.

The key is MORE SPEAKERS with the appropriate amount of power.

^^^THIS!

It is absolutely true that most speakers reach their mechanical limit far before they reach their thermal limit. That's why the marketing departments for cab manufacturers always love to advertise wattage ratings based on the cab's thermal limits...the number is bigger! If they posted their wattage ratings based on mechanical limits, their cabs would look dismal. But most of us savvy TB'ers know better and are not fooled by such plaid jacket trickery.

An exception is the Eminence Kappalite 3015LF driver. That thing is rated at 450 watts but can easily handle nearly twice that and not even flinch because of its mechanical handling capability. That's why the Greenboy fEarful design employing the 3015LF is so popular and provides such a high level of performance. Of course, its outstanding performance in low frequencies means it needs to be crossed over around 1000 hz and accompanied by a mid-driver, but that is, IMO, a much better design that trying to rely on one size driver to handle the entire frequency range.

 

[SteveC]

I've found that 100W with a 4x10 is enough to be heard over drums and other stuff. 100W 1x10 is useless.

I disagree. I'm playing a jazz gig tonight with 175 watt 10" combo and it will be plenty. As others have said, it depends on the gig, the venue, the band, the player, etc., etc.

You really need enough to hear yourself and for the audience to hear you. If you are using a PA, you only need enough to hear yourself. Depending on your bands discipline and stage volume, that could be as little as 100 watts. It could be as much as 1000 watts.

 

[NortyFiner]

So much depends on whether or not you have PA support, and how much. If you are totally dependent on your amp for volume, then obviously you need MORE (of whatever...watts, speakers, etc.) from your amp setup. On the other end of the spectrum, I think Rush runs all DI's and PA; they don't even use amps. And of course, every playing situation is different, which is why it pays to have a flexible rig.

 

[Sundogue]

Watt the hell is going on here?

Watts are almost meaningless.

Speakers. It's about the speakers and the cabs they are in. Sensitive speakers in efficient cab designs will get more out of those seemingly important "watts" than just simply throwing watts at the problem. Inefficient cabs with low sensitivity speakers will need more power, but...

In the context of how many watts a cab can handle, it's about displacement limitation, not how many watts will fry the voice coil of a speaker. So ignore the manufacturer specs on speaker wattage rating. It's just about useless. ALL cabs are displacement limited...every freaking one of them.

How much power is needed? The only REAL definitive answer is...

Enough watts to cover the displacement limitation of the cabs used, and enough of those cabs used to get you to the volume you require.

You can fill in the blanks on what that means.

 

[GrowlerBox]

Testify!

 

[BurningSkies]

I think 200 would do well in a lot of situations, 300 would be better.

I use my LMIII at 8 ohms/300W into a 2x10 for small gigs, and 500W/4 ohms into a 4x10 for larger venues. I have yet to even come close to running out of gas with either setup.

Yet interestingly, I use a LMII with a big set of 15s and in the past a 15+2x12 rig and bumped into headroom and compression issues regularly. Part of the trouble is that what works for one person isn't the same as what works for another. There are sooooo many variables involved that without way more info watts means nothing.

 

[billfitzmaurice]

An exception is the Eminence Kappalite 3015LF driver. That thing is rated at 450 watts but can easily handle nearly twice that and not even flinch because of its mechanical handling capability. .

The displacement limited power of the 3015LF driver is 450 watts, more or less, depending on the cabinet. Feed it twice that and you will see magic smoke.

 

[shadow_FIX]

Yet interestingly, I use a LMII with a big set of 15s and in the past a 15+2x12 rig and bumped into headroom and compression issues regularly. Part of the trouble is that what works for one person isn't the same as what works for another. There are sooooo many variables involved that without way more info watts means nothing.

Right, that's why this question is impossible to answer. We likely have different sonic tastes in our sound, and yours might just require more headroom! I thought it would be a good idea to share my opinion and what worked out for me. For the record I play in two very loud bands with the LMIII+4x10 (Aguilar GS410) and rarely have the master up past 10 o clock.

 

[JimmyM]

i see we've reached a consensus.

 

[GrowlerBox]

i see we've reached a consensus.

That's right -- to summarize: somewhere between 50 and 2500 W through a 110 or an 810 + 415.

 

[seamonkey]

IEMs only need a few milliwatts