A Test. How much Voltage (power) do your speakers need?

I measured the test tone at:

  • 2 volts or less

    Votes: 334 40.6%

  • Between 2-5 volts

    Votes: 252 30.6%

  • Between 5-10 volts

    Votes: 106 12.9%

  • Between 10-20 volts

    Votes: 55 6.7%

  • Over 20 volts.

    Votes: 76 9.2%
  • Total voters
    823
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J

jakubg

Member
Joined 2010
regal said:
Just to give folks an idea of how hard it is to power new ortho headphones, I measured 1.3Vrms with the -12db tracks, thats higher than the majority of speakers meaurements in the poll.
Click to expand...

Don't forget that headphones usually have higher impedances.
Therefore 1.2V into 60 ohms (audeze LCD2) is 0.024 watts.
Its the same as 0.44V into 8 ohms. :eek:

But still, it's a lot of power for headphones (remember you are listening centimeters away, not meters like with speakers). :eek:
 
P

pierre77

Member
Joined 2012
Dear Pano

thanks for the post, I'll take the test asap. I am struggling with the "gain staging" problem.... I never thought about it before I strated to play with active xover!. It's damn important, I realize!

I have the following basic question which has somehow to do with gain-staging and this voltage test all together.

Suppose my speaker have:
Z_min = min impedance across the spectrum,
S = speaker sensitivity in dB/2.83V/1m, anechoic

I want to produce X dB at the Y meters under anechoic conditions. How do I compute:
1. Vmax = the voltage required by the amp
2. Imax = the current need

I hope somebody can give me forumlae to compute those quantities.

Best Regards
Pierre
Ps: I may try to answer that answer that Imax=Vmax/Zmin,
 
weltersys

weltersys

Member
Joined 2008
pierre77 said:
I want to produce X dB at the Y meters under anechoic conditions. How do I compute:
1. Vmax = the voltage required by the amp
2. Imax = the current need
Click to expand...
Pierre,

Voltage x Voltage divided by impedance=watts.

SPL drops at 6 dB per doubling of distance outdoors or in an an anechoic chamber.
A 90 dB one watt one meter speaker driven with 10 watts will be 100 dB, at 2 meters 94 dB, at 4 meters, 88 dB etc.
Assuming a nominal 8 ohm speaker, the 10 watts would require 8.944 volts.
 
Pano

Pano

Administrator
Joined 2004
Paid Member
And as mentioned, that is outdoors or with no reflections. It usually does not drop what fast in a room. If you are in a room, I suggest pink noise playing on both speakers and an SPL meter.

For example: With both speakers playing I get ~84dB at my listening position with 1V on the speaker terminals. I'm not sure what that translates into for each speaker a 1W/1M, but I know the voltage I need to hit 84dB where I sit. :)
 
V

Vaughan

Member
Joined 2004
This method won't determine sudden changes in signal amplitude? If I'm watching a movie like Master and Commander, Chapter 4, before the cannons start, there is almost silence but when the action hits it hits very hard.

Now how would one determine how much voltage was used during those sequences? Because people say you need "x" watts to watch a movie and that more power will help in a given scene.

It would be interesting to put that to the test to test dynamic events from movies at a loud volume and see how much power is being used.
 
V

Vaughan

Member
Joined 2004
But doesn't the procedure use test tones? I'm referring to a dynamic scenes in a movie. I definitely don't believe in occult/unmeasurable phenomena. I believe it's all measurable, but I guess I want to know what the best method would be to test how much power is being used while watching a movies dynamic scenes.

Like the Star Wars Attack of Clones, beginning sequence where the ship flies by and then explodes. Incredibly dynamic, but I would to know how much power is being used up at a given volume. I'm all for learning.
 
V

Vaughan

Member
Joined 2004
I don't know. I don't know if test tones are the equivalent of a dynamic signal, like a movie. I thought test tones were steady state.

If a movie has a scene recorded very loud at a high MV, you are saying that using test tones is going to give the same result if using the MV at the same volume?
 
V

Vaughan

Member
Joined 2004
[QUOTE="mr_push_pull]o, are we doing the "I don't know why but it is wrong" game again? thought we were over that.[/QUOTE]

Sorry I didn't know there was a problem. I haven't read through this thread. I just thought about it for a second and asked you a question. No need to get defensive.
 
A

AndrewT

R.I.P.
Joined 2004
How does one get the test tones on to the video disc as an accompaying sound track?
That way we can compare the maximum output of the CDP with the DVP sound track.
I would expect the DVD used as a CDP would give the same result,
But would a video sound track give the same maximum output as the DVD used as a CDP? There could be a difference since the coding will be very different.
 
A

AndrewT

R.I.P.
Joined 2004
How does one get the test tones on to the video disc as an accompanying sound track?
That way we can compare the maximum output of the CDP with test tones on a CD with the DVD where the tones are on a video sound track.

I would expect the DVD used as a CDP would give the same result, as when a CD is played on that DVD player.

Would a video sound track give the same maximum sound output as the DVD used as a CDP in playing a CD? There could be a difference since the coding will be very different.
 
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