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Whelen SA314P vs. Dynamax

Posted: Thu Aug 21, 2003 11:01 am
by jim
Test was done in my parking lot.

The dB meter was 45' from the speaker in a straight line in front of it and at the same height.

The siren that drove the speakers is a new Federal PA300. 100W rating. Powered at 14.2V by an Astron.

Speaker#1- Federal Dynamax: 113dB at 45'
Speaker#2- Whelen SA314P : 118dB at 45'
Winner: Whelen.

The Whelen produces a "clearer" and more true sound than the Dynamax. To my ear, it's louder (which is why I even did this test to begin with). It's lighter and cheaper. It's also harder to mount with it's rear-mount design. They need side holes like the Dynamax.

I know- they is all kind of meter weighing and other technical aspects of dB measurement, but this was just to see which one used the driver power more efficiently.

Posted: Thu Aug 21, 2003 1:20 pm
by apco25
Interesting, I was going to purchase the whelen units since they are housed in nylon (no rust) are offer a nice in grill mounting for the 03 suburban.

and yes I'll be running a dual speaker setup for 200w

Posted: Thu Aug 21, 2003 5:06 pm
by nmfire10
:o :o Sorry, hang on. I just had to defib myself. Jim, I was expecting something ranting about the poor engineering and quality of a Whelen product. I'm shocked, literally!!!! :P :lol: 8)

Anyway, so how much of a difference is 113 vs 118 db? I've never had them side-by-side before.

I do like the plastic vs the metal. As far as mounting, I've found that any speaker has it's quirks depending on the vehicle. I'm sure there plenty of applications where the Whelen mount would be a lot easier than the federal and vis-versa

Posted: Fri Aug 22, 2003 7:19 am
by USPSS
the KKK requirement for ambulances is 120db at 45 deg at 10 ft.
and with 2 speakers it is 123 db

So a 3 db gain should be a doubling of output.

I have the 314P in the 2004 Impala with a Unitrol Omega behind it and it is VERY LOUD.

Posted: Fri Aug 22, 2003 12:15 pm
by HumHead
Mmmmm dB math... :roll:

In dB:

+3dB = Double the electrical power
+6dB = Double the electrical voltage or four times the electrical power
+10dB = Approxiamtely double the perceived loudness or ten times the electrical power

The dB is simply a logarithmic expression of the relationship between two values. It is meaningless without an indication of the value and measurement units being used as a reference for comparison.

In the case of acoustical ouput, values are expressed in dB SPL (Sound Pressure Level), where 0dB SPL is assumed to be absolute silence, and 1dB SPL is assumed to be the smallest change in level that the human ear can differentiate.

Since there are very few sets of calibrated ears out there, the whole thing is a little bit arbitrary. Then there's the whole issue of wieghting and scaling...

I just hope I never have to run into that high school math teacher who I told that I didn't see why we were learning something as useless as logarithims. :oops:

Posted: Fri Aug 22, 2003 3:36 pm
by jim
Oh! I almost forgot.....most other Whelen products are poorly engineered! ( I just had to say it! :lol: )