How do I know the max volume out of my amp?

[shatteredphone]

Hi all,

First of all, sorry if this is a noob question - I'm really new to all this audio system things.

I've bought a Crown XLS 1502 and a pair of JBL Control 1 Pros. Now, the power output from the amp is 525W and the speakers operate at 150W - I know the amp is overkill but my intention is to use it with more powerful speakers in the future. Following this, I have a couple of questions:

- Both power ratings (525W and 150W) refer to continuous/RMS power, right?
- How much should I set the volume knob in the amp in order not to blow the speakers? About a third?
- Would I benefit from buying a limiter or anything like that? Seeing the prices, seems a little bit excessive.
- Should I buy any other components like a pre-amp or similar?
- Any other advice?

Thanks in advance for the help.

 

[antcollinet]

Hi all,

First of all, sorry if this is a noob question - I'm really new to all this audio system things.

I've bought a Crown XLS 1502 and a pair of JBL Control 1 Pros. Now, the power output from the amp is 525W and the speakers operate at 150W - I know the amp is overkill but my intention is to use it with more powerful speakers in the future. Following this, I have a couple of questions:

- Both power ratings (525W and 150W) refer to continuous/RMS power, right?
- How much should I set the volume knob in the amp in order not to blow the speakers? About a third?
- Would I benefit from buying a limiter or anything like that? Seeing the prices, seems a little bit excessive.
- Should I buy any other components like a pre-amp or similar?
- Any other advice?

Thanks in advance for the help.

Hi

What is your input to the amp?

 

[shatteredphone]

Hi

What is your input to the amp?

Hi!

Thanks for the reply.

I'm using a 1/8 jack out of my laptop to RCA right now but I plan to use a Zed-10/Zedi-10 to connect them with XLR cables as soon as I get it.

Also the amp and speakers are connected through speakon in the amp side and wire on the speaker side.

 

[Balle Clorin]

Be careful , without a volume control or preamp your power amp may get too high signal and fry your speakers. You must keep the volume low enough from the PC to avoid an accident.

 

[Blumlein 88]

The Crown has two settings for sensitivity. I would select the higher one which is 1.4 v RMS for full output. The ZED 10 can put out about 8 volts max. So using an attenuator something like this one between the ZED and power amp is probably a good idea. Will knock down the level by 20 db. Use this near the amp.

https://www.amazon.com/MCM-20db-Balanced-Xlr-Attenuator/dp/B00AZTWGDU

 

[Robin L]

Hi all,

First of all, sorry if this is a noob question - I'm really new to all this audio system things.

I've bought a Crown XLS 1502 and a pair of JBL Control 1 Pros. Now, the power output from the amp is 525W and the speakers operate at 150W - I know the amp is overkill but my intention is to use it with more powerful speakers in the future. Following this, I have a couple of questions:

- Both power ratings (525W and 150W) refer to continuous/RMS power, right?
- How much should I set the volume knob in the amp in order not to blow the speakers? About a third?
- Would I benefit from buying a limiter or anything like that? Seeing the prices, seems a little bit excessive.
- Should I buy any other components like a pre-amp or similar?
- Any other advice?

Thanks in advance for the help.

- Both power ratings (525W and 150W) refer to continuous/RMS power, right?

I kinda doubt that. The Crown amp was reviewed here, the continuous power was more like 300 watts. In any case, the JBL speakers are small and probably would blow out if the full power of the Crown amp was used. I doubt the JBLs would handle 150 watts continuous, that rating is probably for peak power. I wouldn't try and find out just how loud the speakers would get, just have them play at comfortable levels.

- How much should I set the volume knob in the amp in order not to blow the speakers? About a third?

No way to know without having everything plugged in. Use common sense, start low and find out what level sounds right. You shouldn't expect lease-breaking sound levels as these are small, cheap speakers. Once you start hearing distortion, it's time to back off.

- Would I benefit from buying a limiter or anything like that? Seeing the prices, seems a little bit excessive.

No, a limiter would only mess with dynamics.

- Should I buy any other components like a pre-amp or similar?

I've got a Topping L30 headphone amp that doubles as a preamp. The L30 has a three-position rocker switch that allows for three different average levels of output. I have the preamp output hooked up to the AVR (amp) that drives my speakers - Infinity Primus 250s, 2-way tower speakers, the amp puts out 100 watts a side. Usually, I set the rocker to the middle position and the volume control is about 1/3 up. The AVR is set to a position where it would be just a little too loud if there wasn't a preamp in the signal path. Remember - your speakers are small, don't expect too much from them. Bigger, more efficient speakers would allow for more volume. My speakers are bigger and more efficient and are in a small room. If they were in a larger room, their potential level might not be enough.

If you have more than one source, you will need a preamp with multiple inputs. My Topping L30 does not. On the other hand, it's a fantastic headphone amp. In any case, my sources are digital and are hooked up to a DAC with multiple inputs.

- Any other advice?

Remember that the speakers have a limit on the volume they're capable of producing, so don't expect extreme sound levels. A subwoofer would probably help but might not be easy to integrate with the amp you've got.

 

[staticV3]

- Both power ratings (525W and 150W) refer to continuous/RMS power, right?

Here's what the ratings refer to:

How much should I set the volume knob in the amp in order not to blow the speakers? About a third?

It's not that simple.
Output power is a function of input voltage, volume knob position, load impedance, and signal frequency.

You could play a 60Hz 0dBFS test tone on the Crown and set the volume so that the Crown's output voltage with the JBL plugged in doesn't exceed 23Vrms (measure with a multimeter)

Or you could watch the Crown's signal LEDs and make sure that the -10 indicators don't light up. At -10, the Crown will output 10% of its rated power.

Or, more realistically, just be mindful of your volume levels and back off a bit once the JBLs start complaining. If you do that, they'll be fine.

 

[DVDdoug]

- Both power ratings (525W and 150W) refer to continuous/RMS power, right?

Yes but it's "complicated" and "statistical". A 150W amp just-below clipping on the peaks is supposed to be safe with 150W speakers. The speaker usually can't handle 150W continuous test tones, and the tweeter can't handle as much power as the woofer. (And that's if you trust either spec.)

Or if you push the amplifier into clipping/distortion the peaks are limited (clipped) but the average keeps going up and you can blow the speakers that way. (There's a popular myth that an over-powered amplifier is better than clipping but it's not true and both can be bad.)

- How much should I set the volume knob in the amp in order not to blow the speakers? About a third?

Too many unknowns. We don't know the signal level going into the amp and the volume control isn't linear.

In your living room, you're unlikely to be using that much power unless you are "testing" to see how loud you can go, or unless a drunk person is in charge of the volume.

- Would I benefit from buying a limiter or anything like that? Seeing the prices, seems a little bit excessive.

Only if the limiter is monitoring the wattage and only if you keep it below limiting (or only allow occasional limiting) because of that "average power" thing.

- Should I buy any other components like a pre-amp or similar?

It depends on what your source is else you want/need. For example, the Crown has separate left & right volume/gain controls and you don't want to use those for your everyday volume adjustments. Or you may want to switch between different inputs. "Traditionally" a preamp is a "control center" to select between sources and it has volume & tone controls, etc., and the only actual amplification was for a phono cartridge.


A stereo receiver or home theater receiver with preamp-outputs can also serve as a preamp/control center. An AVR can decode all of the movie surround formats.