Bollock dropped advice needed on amp/cab mismatch

[karlfer]

Decided to go back to the simplicity of the wonderful Tec Amp PUMA.
Ordered the 900 watt (4 ohms).
Ten minutes later the dawning. My two Berg AE112 cabs are only 300 watt apiece, so obviously 6oo watts in total .

Any ideas that don't end in buying more bloody gear?

Yours, embarrassed muppet of Wigan.

[JapanAxe]

Cancel your order.

[obbm]

You should have no problem with that as long as "use your ears" and never turn it up full. Just enjoy the headroom. I used a 1200-watt amp into a 600-watt cab for a year without a problem.

[CamdenRob]

[quote name='karlfer' timestamp='1435926898' post='2813683']
Decided to go back to the simplicity of the wonderful Tec Amp PUMA.
Ordered the 900 watt (4 ohms).
Ten minutes later the dawning. My two Berg AE112 cabs are only 300 watt apiece, so obviously 6oo watts in total .

Any ideas that don't end in buying more bloody gear?

Yours, embarrassed muppet of Wigan.
[/quote]

I asked a similar question of Mike at Purple Chilli when I ordered my cabs (300 watts a piece) as I was running a GB Shuttlemax12.2 at the time (1200Watt) I was told that the 300 watts was for a constant signal and the cabs could handle peaks up to double that without any problem.

Those bergs are super sensitive so I doubt you would get anywhere near 600 watts without deafening everyone in the vicinity.

*disclaimer* someone with proper knowledge of these things will be along soon I expect, following my advice is never a good idea, especially when expensive gear is involved...

[Guest bassman7755]

I'm dont see what the problem, your speakers will probably produce gig level volume at 200/300 watts consumption max. The fact that your amp can in theory supply way more than that is not really an issue.

Think of this way - all that matters is the [b]actual[/b] power you put into your speakers to make them loud enough (which is a constant, independent of the amps theoretical maximum power) , how much more your amp may or may not be capable of is immaterial.

I used to run a QSC PLX 1.6kw amp into a 700 watt cab, I also have a puma 900 and happily run it into cabs rated half that power or less.

Edited July 3, 2015 by bassman7755

[Sonic_Groove]

[quote name='obbm' timestamp='1435927304' post='2813688']
You should have no problem with that as long as "use your ears" and never turn it up full. Just enjoy the headroom.
[/quote]

This + 1

[karlfer]

JapanAxe, thank you but wash your mouth out

OBBM and CambdenRob thanks, I'm sure I read Bill Fitzmaurice say similar, so panic (probably) over.

Thanks guys inc mr 7755 and Groove

Edited July 3, 2015 by karlfer

[discreet]

No worries, Karl. You won't be running your Puma flat out or anywhere near it. Your rig will be arse-shatteringly loud way before you get to the point where your drivers will be in any kind of trouble. And I'm sure a bass player of your calibre will know when you're getting there. I had a rig with a 1KW power amp into two 300W-rated cabs - no issues.

Edited July 3, 2015 by discreet

[karlfer]

Thank you Mr. discreet.
I may only play 4 notes per night but I know how to make them count.

How, does one shatter an arse?
On second thoughts DO NOT ANSWER THAT

[72deluxe]

[url="http://www.eminence.com/2010/11/providing-the-proper-amount-of-headroom/"]http://www.eminence.com/2010/11/providing-the-proper-amount-of-headroom/[/url]

According to that informative link, the rule in pro audio is to provide at least twice as much amplifier power as the speaker's continuous power rating. Amplifier clipping is what blows speakers apparently!

This is complete news to me because I always thought you should UNDERPOWER the amp to avoid overdriving the cabinets but in truth it is better to use a more powerful amp, just not turn it up full.

[Ghost_Bass]

I recon, in theory, anyone can kill his cab even with a lower powered amp (example: a 300W amp in a 500W cab), it's just a case of pushing it too far with over-EQ on lower freqs and/or the volume maxed out. The reverse is also true, you can gig a high power amp with a lower powered cab for years as long as you listen to it and don't exceed its limits.

Don't worry and enjoy your new amp

[Ghost_Bass]

[quote name='72deluxe' timestamp='1435930078' post='2813730']
[url="http://www.eminence.com/2010/11/providing-the-proper-amount-of-headroom/"]http://www.eminence....nt-of-headroom/[/url]

According to that informative link, the rule in pro audio is to provide at least twice as much amplifier power as the speaker's continuous power rating. Amplifier clipping is what blows speakers apparently!

This is complete news to me because I always thought you should UNDERPOWER the amp to avoid overdriving the cabinets but in truth it is better to use a more powerful amp, just not turn it up full.
[/quote]

It's not only amp clipping, too much low freqs will make the cones travell more that they're designed to and eventually blow them, too much highs and dirt pedals can easilly blow tweeters.

[chris_b]

This isn't a problem. For 5 years I ran a 500 watt amp through 2 AE112 cabs and never got to half way on the volume controls, and we wern't quiet. I doubt you'd get to the point of doing any damage unless you try to go to 11. And why would you do that?

This should give yo lots of nice headroom for a great sound.

[72deluxe]

Yes, the two limits are thermal limits for a speaker and the mechanical limits, where the speaker hits the end stops. That is why all practice room bass cabinets are wrecked because fools go in and turn all the EQ to max. Ideally decent cabs will have crossovers in them to stop high signals even going to the tweeters, but perhaps I am expecting too much! I did ask Bergantino where the crossover was in a HD210 but they didn't say.

[Owen]

I used to drive 1.6Kw into an Eden 410XLT (700w). I had headroom for days. I had authoritative LF heft. Don't even begin to worry.

[Guest bassman7755]

[quote name='72deluxe' timestamp='1435930078' post='2813730']
[url="http://www.eminence.com/2010/11/providing-the-proper-amount-of-headroom/"]http://www.eminence....nt-of-headroom/[/url]

According to that informative link, the rule in pro audio is to provide at least twice as much amplifier power as the speaker's continuous power rating. Amplifier clipping is what blows speakers apparently!

This is complete news to me because I always thought you should UNDERPOWER the amp to avoid overdriving the cabinets but in truth it is better to use a more powerful amp, just not turn it up full.
[/quote]


Well its all getting a bit complicated, let me try to distil it down ...

1) Use a speaker config capable of delivering the volume you need without suffering damage (to the speakers that is)
2) Use an amp capable of powering the speaker to the level required by rule 1 without hard clipping

Thats it, thats all that matters, relative and absolute power specs of neither the amp or speaker matter so long as rules 1 and 2 are applied.

Edited July 3, 2015 by bassman7755

[72deluxe]

Excellent. Thanks!

[karlfer]

Tell ya wot, yuse guys is amazing, thank you all.

Not like them up there in Off Topic

[alexclaber]

Yes, you'll be fine! The two best rules of thumb are:

1. PA use - amp has twice the power output of the cab's power handling
2. Guitar use - amp has half the power output of the cabs's power handling

For bass guitar? If you're Anthony Jackson (super clean uncompressed high accuracy reproduction of the instrument's sound) then the PA use approach is spot on. If you're Lemmy (heavily overdriven valve amps) then the guitar use approach is the one. Everyone else sits somewhere in between, which why it's so bloody confusing!

[bonzodog]

Yes as has already been said it will be fine. I used to DJ and all DJ forums would always suggest your amp to be twice as powerful in watts as your speakers but must never clip

[Bill Fitzmaurice]

Odd how often this subject comes up. My car has a top speed of 130mph, yet the speed limit is only 75. How does one deal with that issue? [i]Don't put the pedal to the metal. [/i]Seems obvious to me.

BTW, clipping can toast tweeters, but has absolutely no effect on woofers. Sometimes even those who really should know better don't.

Edited July 3, 2015 by Bill Fitzmaurice

[JTUK]

I'd say you have to be VERY careful.
Sure, it should be easy to keep the limits on the volume but how are you going to do that in practical terms..?

Assume half on the dial means half the power on the amp..?? good luck with that..!!
Listen to the drivers stressing..?? ok, in an ideal world but I hope you aren't running effects and don't get me started on distortion pedals..!!
What sort of sound does your band run... can you even hear the cabs stressing ALL the time..??
Don't lend this 'arrangement' to anyone else who doesn't know the deal...that your amp produces twice as much
as your cabs can take, peaks not withstanding.

Of course 600w is very very loud, but who ears do you trust..??

I wouldn't say you can't do it, but I'd say you need to be careful in every situation and that is easier said than done and by then the damage is done.

It is not as tho drivers are very hard to break... they do fail easily enough.
Have a head count of people who have broken or have had a driver break on them in the last few years...
and it doesn't matter what caused the failure, it you break one, you stand a good chance that that failure could impact
onto the second cab..?? IME.

Edited July 3, 2015 by JTUK

[Guest bassman7755]

[quote name='JTUK' timestamp='1435949507' post='2813987']
I'd say you have to be VERY careful.
Sure, it should be easy to keep the limits on the volume but how are you going to do that in practical terms..?
[/quote]

Unless you running a weedy amp theres always a risk of damaging speakers if you don't exercise some degree of care. The only totally safe setup is a powered speaker with a DSP thats been programmed with the specific limits of the driver.

The puma is a very well designed amp and has a very good manual. If you set it up so that the preamp is running right up to the clip limit and take it easy with the master volume theres limited scope for mishaps. Also go easy on the bass boost and low eq controls.

[MacDaddy]

[quote name='karlfer' timestamp='1435926898' post='2813683']
Decided to go back to the simplicity of the wonderful Tec Amp PUMA.
Ordered the 900 watt (4 ohms).
Ten minutes later the dawning. My two Berg AE112 cabs are only 300 watt apiece, so obviously 6oo watts in total .

Any ideas that don't end in buying more bloody gear?

Yours, embarrassed muppet of Wigan.
[/quote]

I'm wanting to hear more about the Puma! I had a play with one at the Herts bash, and thought it was awesome.

[karlfer]

I don't use any pedals or effects.
The main band is a rock covers band, we are loud, but not ear bleedingly so.
Last night the TTE, gain was around 11.30, master around 9 o'clock and that was more than enough.
EQ was bass cut a bit, mid cut a bit treble boosted a bit (all between 11 o'clock and 1 o'clock on the dials). Colour bumped round to about 1 o'clock.
Tweeters off on both cabs, I don't use them.

With using the PUMA 500 for a long time (for me) it was always TASTE at 1o'clock, bit of cut on bass/low mids, bit of boost on high mids/treble.
Gain rarely more than half way round, master usually around 10 o'clock. Lovely, clean, warm, deep sound.
I always like to have gear much more powerful than I will need, never driven any amp past half way on master.

Thanks again.

Edited July 4, 2015 by karlfer