If you listen to modern pop music off CD,(or any other digital delivery) there is no dynamic range so no headroom is necessary.
My brother...................... Same when tightening a bolt, turn it until you hear a crack then slacken half a turn
That's why I use my synthesizers to thoroughly abuse the amp/speakers , from utter silence to "tapping" (bottoming out) the bass driver .. all in the matter of a couple microseconds. 😀
OS
Years ago I measured the current into my biwired Mission 752s using a current probe. I was very surprised to find the tweeter was drawing as much current as the woofer, as it is "common knowledge" that biamped speakers need far less power for the tweeter
In all fairness there are some decent CD's. But I've seen many that are actually clipped most of the time and peak to average levels might just be 5dB or so or sometimes even less !🙁
I think 10 dB is supposed to be for SPL. 1 dB is supposed to be the smallest amount of gain in which human ears can tell there was an increase.
I know most of you will say this is a bunch of crap but one very possible reason I can think of that people might need 1000 watts now but did not used to need that much is because they have a MOSFET amp now. Those things just will not sound loud no matter what you do to them IMO. A real power amp of 1000 watts turned up to just before clipping will blow your house down with good speakers but a 1000 watt MOSFET with the same speakers does not sound that loud. Not to me anyway. But if anybody has a decent BJT amp of at least 600 watts bridged into 4 ohms or more I will trade it straight out for a Studiomaster MOSFET 1000 amp that is 1000 watts bridged into 4 ohms. I will ship the studiomaster first and give you time to check it out before you either ship it back or ship me the BJT amp. If you actually think I am wrong than it would be a great deal for you.
Why am I willing to take that kind of risk? Because it is of no use to me anyway so while I would prefer that it didn't get stolen, if it does get stolen I can live with it. It is not loud enough to power one of my sub-bass cabinets or to power 2 of the other ones so I can't use it. It has enough power but it is not loud enough. I have a JBL and a Crown that are both BJTs and both 600 watts that I can use for all but the sub bass cabinets. Actually I have a lot of other power amps too including 4 Ross .5KWs and some JBLs but I am actually stockpiling them now as many as I can because I fear that one day they might all be MOSFETs and I can't use those. That MOSFET 1000 is not even loud enough (to me) for my home stereo and I have killer PA speaker cabs with EVs.
I know some of you will say there must be something wrong with it and that is why I am willing to ship if first and let you check it out.
Another thing is to my ears MOSFET amps especially don't seem to handle the bottom end well.
Some CD's show clipping according to my mastering software but don't with different mastering software. I have seen a few that showed to be clipping on mine and others. Not that you need a meter to tell. When anything digital clips the slightest bit it sounds terrible.
1KW not loud enough ??? whoa !!... just 200W will make my ears respond and fill with wax after a short session. Outside , someone 1/4 mile away called the law for "disturbing the peace" on just 200w. 200w will also make every object in a 400sq.ft room vibrate off flat surfaces and fall to the floor (ripples in the fish tank , too - rock on, fishies) VERY inefficient speakers maybe ? 😕
OS
OS
A lot of reference to watts! Surely you must understand that watts are not necessarily the determinate for SPL.
How much power does one need for domestic listening?
This is what the original thread was referring to.
First, the reference to "one" (above) is most important because it depends on that person's goals, their background and their present occupation or preoccupation with audio -professional or not.
We could simplify the whole matter by using one example from Bob Katz's Mastering Handbook.
Basically it is a setup somewhat based on SMPTE:
I don't have the reference at hand at the moment, but the following link will shed some light:
Level Practices (Part 2) (Includes the K-System)
Basically, if one wishes to establish a reference system for loudness/power in a given room, one needs to remember that continued use of said room or even changing the listening environment/equipment, requires sound practices for effective listening skills and pleasure, as well, to prevent damage to hearing and the ability to make valuable judgment calls on quality.
After-all the purpose of a proper level is based upon the ear's health.
Although, some deviations from this to either extreme is expected, but we're not concerned with those extremes when kept in check, rather we at DIY are mostly concerned about quality as determined at the listening position-long term.
It is not possible to realistically charge the air of a domicile with the recorded space of a symphonic hall with full symphony.
Have a look at at the link.
How much power does one need for domestic listening?
This is what the original thread was referring to.
First, the reference to "one" (above) is most important because it depends on that person's goals, their background and their present occupation or preoccupation with audio -professional or not.
We could simplify the whole matter by using one example from Bob Katz's Mastering Handbook.
Basically it is a setup somewhat based on SMPTE:
I don't have the reference at hand at the moment, but the following link will shed some light:
Level Practices (Part 2) (Includes the K-System)
Basically, if one wishes to establish a reference system for loudness/power in a given room, one needs to remember that continued use of said room or even changing the listening environment/equipment, requires sound practices for effective listening skills and pleasure, as well, to prevent damage to hearing and the ability to make valuable judgment calls on quality.
After-all the purpose of a proper level is based upon the ear's health.
Although, some deviations from this to either extreme is expected, but we're not concerned with those extremes when kept in check, rather we at DIY are mostly concerned about quality as determined at the listening position-long term.
It is not possible to realistically charge the air of a domicile with the recorded space of a symphonic hall with full symphony.
Have a look at at the link.
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quote :
"Once had that particular version of amp in for repair, and found that the main PCB board was conducting, i.e. the plastic/paxolin actual board was conductive. It was dry, and showed no water type damage, but everything was shorting to everything else Never really got to the bottom of it, there was no smell of solvents, no burn marks, but you could literally dig your probe into the surface of the board and get continuity between any two points, tracks or bare board."
Studiomaster 1600D bridge mode help - Speakerplans.com Forums - Page 1
Philmagnotta wrote 'A lot of reference to watts! Surely you must understand that watts are not necessarily the determinate for SPL.'
You can trade dBs for Watts or horsepower or whatever ....
The simple answer is about 100W
To hear appreciable difference about that you would need 1000W
But you need a good 100W amplifier. One that is capable of delivering 100W RMS with the ceiling to deliver peaks above this.
To hear appreciable difference about that you would need 1000W
But you need a good 100W amplifier. One that is capable of delivering 100W RMS with the ceiling to deliver peaks above this.
How did you carry out the experiment?
I have been, what seems like, "preaching" this message for years and few if any want to believe.
It's not just the claimed power delivered to a resistor.
Speakers are reactive. They demand current in response to voltage drive.
A 100W into 8r0 amplifier must deliver 5Apk into 8r0 when reaching the maximum of 100W of output power.
However speakers can demand currents upto around three times what one would expect an equivalent resistor to draw, i.e. 15Apk for a 100W into 8r0 amplifier.
A 100W into 4r0 must have the ability to deliver even more current to satisfy the demands of speakers driven with fast transient voltages.
I would expect an amp that can only deliver a peak current of 10Apk at -1dBV to not sound as powerful as an amp that can deliver 20Apk @ the same -1dBV.
For your 1000W example (1kW into 4r0), this translates to 89.4Vpk and 22.4Apk into a 4r0 resistor and 61Apk into a 1r3 resistor for -1dBV ref 89.4Vpk
If it can only supply half that current at -1dBV then it will not sound as loud as an amplifier that can meet that specification.
Speakers are reactive. They demand current in response to voltage drive.
A 100W into 8r0 amplifier must deliver 5Apk into 8r0 when reaching the maximum of 100W of output power.
However speakers can demand currents upto around three times what one would expect an equivalent resistor to draw, i.e. 15Apk for a 100W into 8r0 amplifier.
A 100W into 4r0 must have the ability to deliver even more current to satisfy the demands of speakers driven with fast transient voltages.
I would expect an amp that can only deliver a peak current of 10Apk at -1dBV to not sound as powerful as an amp that can deliver 20Apk @ the same -1dBV.
For your 1000W example (1kW into 4r0), this translates to 89.4Vpk and 22.4Apk into a 4r0 resistor and 61Apk into a 1r3 resistor for -1dBV ref 89.4Vpk
If it can only supply half that current at -1dBV then it will not sound as loud as an amplifier that can meet that specification.
I was curious about what you mentioned and just gone and did some interesting measurement. I use quad-amped system with electronic cross-overs and drivers are connected directly to the amplifier outputs.
I used both signal generator and music. With the signal generator I used both white noise and single frequency, the currents drawn by all the drivers were the same. White noise have the same power density distributed over the entire bandwidth.
However, with music (Pat Coil - Just for today) there is 1/10 difference between the tweeter and mid/mid/bass average current.
While heavy rock (Budgie's- Breadfan) the difference was 1/6 the average current of the mid/mid/bass average current.
Because of the peaky nature of music I used the Fluke 97 scope meter to average readings over a 20 second period. The amplifiers are all identical and the tweeters are Scanspeak DS2008, 8 ohms nominal impedance. Cross over frequency is 3.7 kHz
While this is not a conclusive test, I would tend to say that the average power ratio between the tweeter and other drivers of the typical music I listen to is about 16 dB.
Also keeping in mind that this is average, there are peak currents in any of the drivers that far exceeds the peak current of the other driver at any one time all depending on frequency distribution and instantaneous intensity. If I performed a peak hold measurement over the same 20 second period the measurements are virtually the same for the rock recording.
While I do not listen to Trance and Heavy Metal or highly compressed music, this ratio could be quite different and approaching the same current for all drivers all of the time.
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Andrew I now read your post and yes I think that your point is absolutely valid and in contrast with my previous assumptions.
I need to add one more observation while the equipment is still lying around. When using a sine wave in the low frequency region as input the highest current was drawn by the KEF B139 woofer for the same terminal voltage as for any of the other speakers in their pass-band region. The reason is simple it has the highest mechanical mass as well as the highest air loading. Adding a bit of mass to the cone in the form of a ball of putty increased the current significantly.
Now this brings another question to mind, how would a valve amplifier which is esentially a voltage source perform against a typical transistor amplifier which is a current source. Obviously as the driver dynamic impedance drops a valve amplifier output voltage would drop if it needs to source more current, or am I missing something?
Now this brings another question to mind, how would a valve amplifier which is esentially a voltage source perform against a typical transistor amplifier which is a current source. Obviously as the driver dynamic impedance drops a valve amplifier output voltage would drop if it needs to source more current, or am I missing something?
most "normal" Valve (Tube) amps and Solid State amps are voltage sources. But they don't have infinite current capability.
I think it is the limited current capability that brings about the output impedance. If current capability were infinite, then I think that implies a zero output impedance.
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