Re: What is SPL at 1 watt RMS input measured 1 meter? nt

Posted by oldroadie (A) on July 29, 2005 at 14:37:32

In Reply to: What is SPL at 1 watt RMS input measured 1 meter? nt posted by grhughes on July 19, 2005 at 08:16:41:

The standard for rating how efficient a loudspeaker plays is to send a tone into the driver with 1 watt, and measure the response at 1 meter. This measurement give you the Sound Pressure Level (SPL) at 1 watt/1 meter.
Once this is known, every time you double the power, you can add 3db SPL. Up until the speaker frys from power.

Efficiency ratings are inportant since, if you know how loud the speaker can play with adequate power, you can figure out how loud it is going to sound in the room. This calculation is called the iverse square rule, where every time you double the distance away from the speaker, you lose 6db.

For instance:

Speaker plays 99db @ 1w/1m
Speaker can deal with 700w peak
You give the speaker 512w
So the speaker is playing @ 129db at 1m with 512w.
That means 100' back in the room, the speaker is producing 99db
That should get you through your rock show.
But people next to the speakers will suffer ...

Tom

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Follow Ups Full Thread

Topic - what is the best pro amplifier for horn subwoofer? - adkins 22:13:18 07/18/05 (12)

for use at home in a 18 x 28ft room - adkins 08:37:25 07/22/05 (2)

Re: for use at home in a 18 x 28ft room - meganumb 14:53:08 08/01/05 (0)

Re: for use at home in a 18 x 28ft room - oldroadie 09:17:49 07/22/05 (0)

Re: what is the best pro amplifier for horn subwoofer? - Inmate51 15:50:16 07/19/05 (0)

Re: what is the best pro amplifier for horn subwoofer? - oldroadie 10:40:37 07/19/05 (0)

Re: what is the best pro amplifier for horn subwoofer? - STUART 10:25:57 07/19/05 (0)

Re: what is the best pro amplifier for horn subwoofer? - Bob Lee (QSC) 09:39:40 07/19/05 (1)

100-watt tube or 800-watt solidstate for basshorn? - adkins 05:27:28 08/05/05 (0)

What is SPL at 1 watt RMS input measured 1 meter? nt - grhughes 08:16:41 07/19/05 (3)

Re: What is SPL at 1 watt RMS input measured 1 meter? nt - oldroadie 14:37:32 07/29/05 (2)

I knew that...I was trying to get the poster ....... - grhughes 17:01:22 07/29/05 (1)

my bad n/t - oldroadie 18:02:53 07/29/05 (0)

Follow Ups

Re: What is SPL at 1 watt RMS input measured 1 meter? nt - oldroadie 14:37:32 07/29/05 (2)

I knew that...I was trying to get the poster ....... - grhughes 17:01:22 07/29/05 (1)

my bad n/t - oldroadie 18:02:53 07/29/05 (0)

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