RE: Does lower sensitivy mean lower resolution?

Posted by tomservo (M) on July 20, 2012 at 14:40:59

In Reply to: Does lower sensitivy mean lower resolution? posted by deadlyvj on July 20, 2012 at 09:09:19:

There isn’t a yes / no answer as a number of things are involved.

The sound level falls 6dB every time you double the distance to the speaker so the closer you are to the speaker, the easier it is to reach a given sound level.

With a sensitivity of 80dB (1 Watt 1 Meter) and if you sat 4 meters from the speaker, you know the level the speaker is producing will be about -12dB from a one meter distance.

If the speaker could handle say 50Watts that mathematically speaking the maximum level the speaker could produce would be (10X the log of input power) over the 1Watt sensitivity or 96.9dB spl.
At the listening position 4 meters away (not including reflected room sound) the Spl would be 84.9dB

Speakers are not dynamically linear, if you double the input power it doesn’t always get twice as loud.

At a level about 1/10 to 1/8 a drivers rated electrical power, the heating of the voice coil wire causes the drivers parameters to change and the sound level falls short relive to the linear case.

Thus, if you want linearity, you need to operate the driver well under its capacity and that is one reason pro-sound drivers are sometimes used in hifi, they are loafing along.

Now music.
Music or most music has dynamic range, it goes from soft to loud, typical FM radio rock has about a 10dB difference between the largest peaks and the average level, that means the peaks represent 10 X the average power.

A good “hifi” demo track on the other hand may have 20 or 30dB or occasionally larger difference between the peak and average levels and what we hear as "loudness" is nearly the average level .

In the case above, if one played on of those good recordings with a lot of dynamic range, say 30dB, this would then mean that your average level must be -30dB down from the maximum level your speaker can produce or the peaks will not be produced. At the listening position, in the example, that average level could be no more than 54.9dB spl (would work in a very quiet space.

My taste is dynamic range and no compression. Take an SH-50 a single source full range horn that has a sensitivity of 100dB 1W 1M. That speaker can produce 100X or +20dB more sound for a given input power.
Power handling, with pink noise (worst case) at the first point where the frequency response deviates only 3dB from the 1 Watt curve due to power compression, takes over 600Watts average input power (and a 2400Watt amplifier to source the signal). If one drove it that hard at the same 4 meter distance would produce a peak level of 121.8 dB or with that hifi recording and 2400Watts peak, an average level of 91.8dB

How loud do you need it, how far away are you from the speaker what the program material is, how much power you have and system sensitivity and power handling all come into what is needed to be faithful to the signal.
Best,
Tom Danley
Danley Sound Labs

here these are sh-50's (Open in New Window)

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Follow Ups Full Thread

Topic - Does lower sensitivy mean lower resolution? - deadlyvj 09:09:19 07/20/12 (39)

RE: Does lower sensitivy mean lower resolution? - tmsorosk 17:22:33 07/22/12 (0)

RE: Does lower sensitivy mean lower resolution? - hahax@verizon.net 14:03:57 07/22/12 (0)

RE: Does lower sensitivy mean lower resolution? - villastrangiato 20:49:59 07/21/12 (4)

RE: Does lower sensitivy mean lower resolution? - chocolate_lover9999@yahoo.com 09:43:32 07/22/12 (1)

RE: Does lower sensitivy mean lower resolution? - villastrangiato 18:28:45 07/22/12 (0)

Don't you think you're being a bit overly pedantic here? The OP was really posing a generalized question. - cfb 06:30:33 07/22/12 (1)

RE: Don't you think you're being a bit overly pedantic here? The OP was really posing a generalized question. - villastrangiato 18:19:58 07/22/12 (0)

RE: Does lower sensitivy mean lower resolution? - middleground 18:23:03 07/21/12 (2)

RE: Does lower sensitivy mean lower resolution? - ahendler 19:32:26 07/21/12 (1)

RE: Does lower sensitivy mean lower resolution? - middleground 13:01:52 07/22/12 (0)

Compare the Stax F-81s to K-horns - plantsman 03:39:34 07/21/12 (14)

Funny thing about the STAX F-81... - morricab 14:47:14 07/22/12 (1)

Here tis---- - Des 23:21:18 07/22/12 (0)

Top 3 speakers that vie for least efficient ever, Stax F81, Large Apogee and the AHL Tolteque plasma - cfb 06:02:53 07/21/12 (11)

Don't forget the Dayton Wrights - Des 16:08:29 07/21/12 (10)

Inefficiency wasn't the issue - E-Stat 06:52:24 07/22/12 (1)

Would've been surely with no SF6 as poster below nt - Des 16:55:24 07/22/12 (0)

RE: Don't forget the Dayton Wrights - drlowmu 19:03:31 07/21/12 (6)

If you drove the primary of the transformer direct - Des 01:35:09 07/22/12 (0)

The problem is too many have been repaired over the years without the SF6, Sulfur hexafluoride gas. - cfb 19:13:47 07/21/12 (4)

Ah yes the Beeyootiful smell of SF6 in the morning Ha! nt - Des 01:31:11 07/22/12 (3)

The good doctor Cooledge - E-Stat 07:00:33 07/22/12 (1)

Yep --Been there did that - Des 16:53:29 07/22/12 (0)

Supposedly, said with one's best Duvall imitation. ;-) - cfb 05:50:34 07/22/12 (0)

Yes, let's not leave out the 1970s products, the Infinity Servo Static 1 and the Koss model 1, both of - cfb 19:02:52 07/21/12 (0)

Cabasse - Belgarchi 21:29:04 07/20/12 (1)

RE: Cabasse - hahax@verizon.net 18:43:15 07/21/12 (0)

RE: Does lower sensitivy mean lower resolution? - tomservo 14:40:59 07/20/12 (1)

RE: Does lower sensitivy mean lower resolution? - deadlyvj 19:31:52 07/20/12 (0)

RE: Does lower sensitivy mean lower resolution? - JNS 12:45:10 07/20/12 (1)

RE: Does lower sensitivy mean lower resolution? - Pro Sound Guy 14:20:08 07/20/12 (0)

Dynamics a bigger issue - Salectric 12:12:00 07/20/12 (3)

Speakers need amps to drive them....... - drlowmu 19:19:45 07/21/12 (1)

You hit the nail right on the head, IMHO - Jay Buridan 09:48:49 07/22/12 (0)

definitely agree - Joe Murphy Jr 19:22:24 07/20/12 (0)

RE: Does lower sensitivy mean lower resolution? - Kloss 10:07:23 07/20/12 (0)

Well.... not outright - badman 09:17:08 07/20/12 (2)

Depends on whether you are listening to Mahler or Morton Feldman - plantsman 14:37:23 07/20/12 (0)

RE: Well.... not outright - deadlyvj 09:51:46 07/20/12 (0)

Follow Ups

RE: Does lower sensitivy mean lower resolution? - tomservo 14:40:59 07/20/12 (1)

RE: Does lower sensitivy mean lower resolution? - deadlyvj 19:31:52 07/20/12 (0)

RE: Does lower sensitivy mean lower resolution?

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