dbx Soundfield V
- Thread starter MichaelK
- Start date
Could be peak RMS. The two terms are not contradictory or opposite.
The term RMS power is an oxymoron made up by amplifier companies to confuse the market back in the electrical musical instrument growth era.
Having a high bottom end for a power spec may mean the speaker does not perform well at lower listening volumes. This is classic sales pitch hype where the saes guy blasts the speakers/amplifier to show you how good they sound at high volumes.
Once purchased at home, you find it sounds muddled, at lower listening volumes, where the linear curve doesn't go.
The term RMS power is an oxymoron made up by amplifier companies to confuse the market back in the electrical musical instrument growth era.
Having a high bottom end for a power spec may mean the speaker does not perform well at lower listening volumes. This is classic sales pitch hype where the saes guy blasts the speakers/amplifier to show you how good they sound at high volumes.
Once purchased at home, you find it sounds muddled, at lower listening volumes, where the linear curve doesn't go.
samgreco
Active Member
Actually: http://knowledge.sonicelectronix.com/car-audio-and-video/car-amplifiers/rms-vs-peak-power/
I was being general in my comment, but there really is a difference. Where the amplifier companies get tricky is in HOW they measure power. They can say an amp is 200W/Ch RMS. But is that at 1khz? Or at the full range of 20hz to 20khz. HUGE difference. But peak is the absolute most output a device can output. RMS is an average from 0 to Peak. So yes, there is a difference.
But they other numbers are critically related to power. Not just the measurement frequency, but at what THD (total harmonic distortion). An amp rated at 250W RMS at 1% THD at 1khz, is not as much power as one at 250W 0.01% THD, by a long shot.
Unfortunately, amplifier manufacturers do not seem to want standard measurements.
I was being general in my comment, but there really is a difference. Where the amplifier companies get tricky is in HOW they measure power. They can say an amp is 200W/Ch RMS. But is that at 1khz? Or at the full range of 20hz to 20khz. HUGE difference. But peak is the absolute most output a device can output. RMS is an average from 0 to Peak. So yes, there is a difference.
But they other numbers are critically related to power. Not just the measurement frequency, but at what THD (total harmonic distortion). An amp rated at 250W RMS at 1% THD at 1khz, is not as much power as one at 250W 0.01% THD, by a long shot.
Unfortunately, amplifier manufacturers do not seem to want standard measurements.
samgreco said:
Let's see if I can translate that.
A powerful amp set to low and medium levels is better than a weak amp cranked up.
Is that correct?
samgreco said:
I know about THD; speakers can be driven hard if the THD is low, but a high THD is bad, and could blow the driver.
Maybe music is just so complex that audio companies can't settle on a standard calculation to rate a driver and amp.
samgreco
Active Member
The only reason they won't settle is because it is easier to confuse people and make their products look better than they really are. I sold both consumer and pro audio products for many years, and trying to explain that the two amps with labels that said "250 Watts RMS!" were not the same at all, was very, very difficult.
The idea of more power being better is that what blows speakers most often is an amplifier going into clipping (hard distortion) from being driven to it's limits. So a 20 watt amp being pushed to it's very limits to achieve the desired sound levels will blow the speaker, where as an amp cruising along at 20% capacity to get to the same level will never get near clipping.
I worked for a company that (among many thing) repaired speakers. And the great bulk of them, that weren't just dried up and old, were blown because of a clipping amp.
The idea of more power being better is that what blows speakers most often is an amplifier going into clipping (hard distortion) from being driven to it's limits. So a 20 watt amp being pushed to it's very limits to achieve the desired sound levels will blow the speaker, where as an amp cruising along at 20% capacity to get to the same level will never get near clipping.
I worked for a company that (among many thing) repaired speakers. And the great bulk of them, that weren't just dried up and old, were blown because of a clipping amp.
For load devices they can handle a continuous amount of power and a peak/surge amount of power delivered for X amount of time.
Any signal power is always measured in RMS values. Anything else is just a crock.
Power output devices have various ways of stating what they can put out. Continuous power and peak power being some of the terms they throw around. Of course then there is stipulations like at x% THD, at y% IMD, etc. into 4 ohms, into 8 ohms, into 2 Ohms, sometimes resistive load is specified (which doesn't happen in a magnetic speaker), but usually no specification of the pf. of the load. Amplifiers don't like the current supplied to be out of phase with the voltage they supply.
Amplifiers are sold by salesmen that wouldn't know a kWh from a kW.
It all sounds good except that different distortion levels sound better than others. The old class A tube amplifiers with 10% Distortion sounded better to the human ear that the new solid state class AB amplifiers with 0.2% THD due to the distortion being crossover distortion that irritates the human ear.
At the low volume end the crossover distortion, being almost constant can become 30-60% of the output, at low volumes. This is why they never state those figures and don't demonstrate those volumes in a noisy store and it sounds like shite.
Back to the OP.
Recommended is just that and not a power handling capability.
Any signal power is always measured in RMS values. Anything else is just a crock.
Power output devices have various ways of stating what they can put out. Continuous power and peak power being some of the terms they throw around. Of course then there is stipulations like at x% THD, at y% IMD, etc. into 4 ohms, into 8 ohms, into 2 Ohms, sometimes resistive load is specified (which doesn't happen in a magnetic speaker), but usually no specification of the pf. of the load. Amplifiers don't like the current supplied to be out of phase with the voltage they supply.
Amplifiers are sold by salesmen that wouldn't know a kWh from a kW.
It all sounds good except that different distortion levels sound better than others. The old class A tube amplifiers with 10% Distortion sounded better to the human ear that the new solid state class AB amplifiers with 0.2% THD due to the distortion being crossover distortion that irritates the human ear.
At the low volume end the crossover distortion, being almost constant can become 30-60% of the output, at low volumes. This is why they never state those figures and don't demonstrate those volumes in a noisy store and it sounds like shite.
Back to the OP.
Recommended is just that and not a power handling capability.
samgreco
Active Member
I know a whole lot of really good people selling amplifiers that know a whole lot about their products. Not all salesmen work for BestBuy.
And I'm not trying to start a range war or anything, but LarryLix, it seems that you're saying the specs don't matter and you can't believe any of the salespeople. So then nothing matters?
MichaelK, I don't know where you live and if you are looking for a new amp, or if you are trying to buy a used one. But I know a whole lot of people in that business (even though I am no longer in it) that I could recommend. Especially in the Chicago area.
And I'm not trying to start a range war or anything, but LarryLix, it seems that you're saying the specs don't matter and you can't believe any of the salespeople. So then nothing matters?
MichaelK, I don't know where you live and if you are looking for a new amp, or if you are trying to buy a used one. But I know a whole lot of people in that business (even though I am no longer in it) that I could recommend. Especially in the Chicago area.
