Which power amp for bass?

[johnk_10]

so why does my amp have only a 12 amp breaker and not a 15 or 20 amp breaker? answer that Mr. engineer!

your amp has a 20 amp breaker. please learn to read your owner's manual, and try to understand it before you attack me with your unsubstantiated and false comments.

Apparently you aren't man enough too accept a challenge. I given you facts from an respected Audio engineer/tech and test results I have done to confirm it, but you ignore it.

this has nothing to do with being 'man enough'. i'm sorry, but you have presented NO 'facts' whatsoever, and your 'opinion', amperage measurement (without wattage measurements), with or without your insults is not going to change physics.

 

[pnut166]

C`mon kids - cool it. You guys are taking over the thread. FWIW though, 3k watts from 7 amps does seem impossible, and I know nothing about amp circuitry. I do know I`ve never seen any kind of amp - be it audio, guitar, PA, etc. even come close to this claim. So, fourstring - I think you are probably mistaken about your amp, but let it go, dude - the rest of us don`t come here to see you guys arguing about something pointless. As long as you`re happy with it, that`s all that matters.

 

[johnk_10]

Hi

I'm looking to enhance my current rig by adding more power and extra cabinents.
I could get a Crown XTi series with double the power, but I've heard they are plagued by quality issues. Also most of good deals on those are B-Stock. Some sellers are honest and mark the items as such, but I bet some won't do that. How would I tell B-stock from "normal" item. I don't want to buy a lemon. Or should I stay away from Crown alltogether?


Any enlightment in the matter is greatly appreciated.

Kind regards

MP

Hi MP,
i have five Crown xti power amps (two xti1000's and three xti2000's) all 5 of them have worked flawlessy and sound great (and i've pushed them very hard) IMO, i think that you would be very pleased with them. i bought all of them brand new for a great price and none of them are B-stock. i can highly recommend the xti2000. at 18.5lbs with 2K watts (bridged @4 ohms), IMO, you get quite a bit of power (and DSP features) for the money, and yet it still is a pretty lightweight amp to haul around.

 

[BBEgo]

My Crown XTi1000 is wonderful. it has all the power I need, is easy on the eyes, and sounds great.
having said that, if I could make up the difference in cash right now, I'd probably sell it and just buy a GB ShuttleMax 12.

 

[Sickneedhelp]

just an FYI. while those are very nice amps, there's no way any amp can produce 3K watts and draw only 7 amps. your crest amp draws alot more than 7A at peak.

here's its actual specs:

Circuit breaker rating (120V/230V): 20A /12A
Current draw (120VAC) 1/8 power, 4 ohms: 7.0A
1/3 power, 4 ohms: 14.0A

Acutally, most of the peak power is supplied by the energy stored in the power supply caps. The issue then becomes what is the average draw. Peaks won't change that much assuming adequate energy storage. As my old friend Bob pointed out, the consumption at 1/8 power is considered typical music. Bass guitar usually averages less than 1/8 but with strong peaks (again, supplied by the caps). Ultimately it gets down to how much the designer skimped on storage caps to meet management's price point. All that aside, the consumption specs on the back panel are based on 1/8 power as per safety agency requirements. Seven amps for a 3kW amp is realistic if it's a high efficiency design. One could say that his 3kW amp only draws seven amps. One could also say, full power requires 20 amps. It depends on if you are referring to music or sine waves. Having the circuit breaker sustain much more than 1/3 power is pointless. It allows you to run sustained full power on the test bench with sine wave input, but in return doesn't give you as much protection in a real world fault condition that could set your speaker on fire. What the amp draws on average with music driven to clip is what matters for an input current rating.

May there be peace and calm in this thread. Both sides are correct from their perspective.

 

[Stevem627]

I can tell you that the MB1200 is a fantastic power amp and I love mine...but it is heavy. I have used lighter weight power amps from Crown and Mackey but they didn't seem to have the same punch on the low end.

This is a VERY subjective decision and I'd dedcide by weight and "feel" if you have a chance to test them with your preamp and bass.

 

[shadowmac]

I have the QSC PLX3602 in my main rig - Yeah, a lot of power and I love it. I am currently assembling a second rig using different components and have settled on the Crown XTi series 2000 or 4000 is yet to be determined. I'm a believer in the statement that you can't have too much power. The QSC and Crown offer much in the way of versatility of use in the case that I choose to use them for something outside my bass rigs.
There is no question that Crest makes great amps, though I have not used them in a bass rig I used them exclusively for PA sound for years. Solid Workhorses!
I've also heard great things about the Carvins for years, but my main concerns for amp choice are power, distortion ratio, weight and features. QSC PLX and Crown XTi amps win that battle in my eyes.

Good Luck.

 

[N. Kentucky Bass]

A good power amp + pre is a beautiful thing to hear. The QSC PLX3602 + Genz Benz ShuttleMAX12 have provided flawless performance. Plenty of overhead. Reliable. I guess another brand of power amp might sound subtly different, but it seems like most of tonal coloration will come from the preamp, bass, strings, fingers/pick, and EQs....

 

[projectMalamute]

I'm an not and do not claim to be a tech.

That much is clear.

The facts are there, my amp has only a 12 amp breaker ...

Your amp has a 20 amp breaker. If it was configured to run at 230 volts it would have a 12 amp breaker.

At 1/8 pink noise the amp draws about 7 amps.

That's at 1/8th power. Let me repeat that: 1/8th. Here's an exercise for you: if full power is 3000 watts, how many watts is 1/8th power? It's not a trick question.

I freely admit I'm not a tech or engineer but I surely don't argue facts if I don't know what I'm talking about. That is the definition of ignorance.

Alrighty then...

 

[pvbassfan]

Crest CA9 is the absolute best if you don't mind the weight.

This. David Ellefson's been using them for years to drive multiple cabs.

 

[Bob Lee (QSC)]

You're not going to get a continuous 3000 watts on 7 A at 120V. But you don't need to except on a test bench.

The current draw specs for 1/8 of full power are measured with pink noise, with occasional peaks that hit full power. It's roughly analogous to pushing the amp about as hard with you can go with music before clipping has the potential to start affecting the sound quality. So it's reasonably representative of the worst-case current draw that you'll experience in real life--i.e., if you're not doing full power sine wave tests on a bench.

 

[Growly Lytes]

Thanks Bob for the info finally.
I use an amp i dont think is available in the U.S just yet called.....
E-Systemspro`Power3000 Installation Series. It has massive headroom giving 1530watts into 4ohms stereo & 3400watts bridged into 4ohms.I dont hear any colouration in sound. The amp only amps the sound of my Sansamps beatifully. I agree that hearing a well balanced Pre/Power set-up is just amazing.I really dont think poweramps change or colour sound much if any.Heres a link to the amp ive got, its great.
Invalid Link Removed

 

[Foz]

Here's some data on a 4000 watt amp doing what Bob is talking about in the real world...

Invalid Link Removed

Note that the amp draw varies with the load and the output level relative to clipping but as Bob explains it aint never gonna make 4000 watts continuously anywhere but the bench [that'd pull 33.33 amps off a 120v line].

If it did that in the real world you'd need a clothes drier plug to hook it up.

 

[babebambi]

Bob, thanks for chiming in.
When you have a chance, can you please specify whether you mean music from a CD, or something like bass guitar in a live situation.

You're not going to get a continuous 3000 watts on 7 A at 120V. But you don't need to except on a test bench.

The current draw specs for 1/8 of full power are measured with pink noise, with occasional peaks that hit full power. It's roughly analogous to pushing the amp about as hard with you can go with music before clipping has the potential to start affecting the sound quality. So it's reasonably representative of the worst-case current draw that you'll experience in real life--i.e., if you're not doing full power sine wave tests on a bench.

 

[Antipodean]

Back to original question, I use a QSC RMX1450 bridged, and apart from the weight I'm really happy with it. It's nice to have the low cut filters to save my speakers.

 

[Growly Lytes]

Ive even ditched both my Fender BXR200 head & TB-600 head for this poweramp coupled 2 Sansamps RBI/RPM.The Sansamps can reproduce any of the sounds & more of what the Fenders could plus the power this baby has its crazy.Its craps on the Fender MB-1200 for power too.

 

[Bob Lee (QSC)]

Bob, thanks for chiming in.
When you have a chance, can you please specify whether you mean music from a CD, or something like bass guitar in a live situation.

Yes, those are two possible sources.

 

[Webtroll]

If you'd like an underpowered single channel back breaker that won't fit in most rack cases let me know and I'll give you a deal!

 

[Sickneedhelp]

You're not going to get a continuous 3000 watts on 7 A at 120V. But you don't need to except on a test bench.

The current draw specs for 1/8 of full power are measured with pink noise, with occasional peaks that hit full power. It's roughly analogous to pushing the amp about as hard with you can go with music before clipping has the potential to start affecting the sound quality. So it's reasonably representative of the worst-case current draw that you'll experience in real life--i.e., if you're not doing full power sine wave tests on a bench.

Here's some data on a 4000 watt amp doing what Bob is talking about in the real world...

Invalid Link Removed

Note that the amp draw varies with the load and the output level relative to clipping but as Bob explains it aint never gonna make 4000 watts continuously anywhere but the bench [that'd pull 33.33 amps off a 120v line].

If it did that in the real world you'd need a clothes drier plug to hook it up.

So if you add the "normal use" qualifier, per the Crown spec sheets, one could say their 3600 watt amp (20-20k spec) draws 7.8 amps. Perhaps this is what caused the confusion when fourstringburn stated a seven amp spec for the CD3000.

 

[bongomania]

One could say that as long as one also said that the amp would not be putting out anywhere near 3600W like 99% of the time, only hitting that wattage level on very short occasional spikes.