# Type RF X2?



## psychot|K (May 2, 2008)

Has anyone had any experience with the 2 channel type RF amps from Rockford Fosgate? I have an X2 but I'm unsure as to whether or not it's the 2002 model (60x2 @ 4) or the 2004 (125x2 @ 4). Because of this, I'm thinking about getting something I'm a bit more sure of. 

Any suggestions? I heard ARC, audison, PPI art are some good choices.

Anyone know how I can check the vintage of my X2? I don't have the birth-sheet anymore 

Thanks!


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## DejaWiz (Sep 20, 2007)

Can you take a tape measure and provide the physical dimensions of the amp as well as the fuse rating? Would help in determining the model.


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## psychot|K (May 2, 2008)

DejaWiz said:


> Can you take a tape measure and provide the physical dimensions of the amp as well as the fuse rating? Would help in determining the model.


Will do!
However, when I look up in the manuals for both the 2002 and 2004 years, the fuse rating and physical dimensions are listed as the same...


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## DejaWiz (Sep 20, 2007)

Any decals on it? Maybe it states if it's an X2, X2.A, or X2.C which would help make the determination.


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## psychot|K (May 2, 2008)

Nope... nothing that I can see...
It's a total mystery.

Any way I can test it somehow? I mean... output has to be different considering an 04 unit has over twice the power of an 02 made X2.


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## DejaWiz (Sep 20, 2007)

You can if you can get or have a test tone and a DMM handy.
(be sure to disconnect all speakers that are hooked up to all amps before testing; this includes subs)

Use the following formula:

WATTS = (Voltage * Voltage) / Ohms


Example: 
- Make sure the amp gain is set so that it isn't clipping the speakers.

- Disconnect all speakers, then play a test tone around 1 kHz at approx 75% max HU volume (or whatever volume the gains were set at) and take a measurement with the DMM at the amp's speaker output terminals.

Let's say you measure 12.3V.

12.3 * 12.3 = 151.29

159.21 / 4 = 37.8

The output per channel is 37.8 Watts. Safe to assume you'd have the 2x50w rms variant (even though a Type RF X2 will probably do well more than rated).

Let's say your measurement is 28.7V.

24.7 * 24.7 = 610.09

610.09 / 4 = 152.5

Output per channel is 152.5 Watts.


Second option is to take it to a shop and have them bench test it. Likely run you $30-50.
Hope this helps.


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## psychot|K (May 2, 2008)

DejaWiz said:


> You can if you can get or have a test tone and a DMM handy.
> (be sure to disconnect all speakers that are hooked up to all amps before testing; this includes subs)
> 
> Use the following formula:
> ...



That's a great idea!!!
Afraid I don't have a test tone CD handy though.
Will taking an average over a 'normal' passage of music (perhaps classical) work as well?


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## DejaWiz (Sep 20, 2007)

Yeah, it could give you a rough estimate. Generally, music will be 50% output of a test tone, so just double the voltages before you plug them in to the formula. It's not going to be very accurate, but you might be able to get an idea of what your amp is capable of.


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## DejaWiz (Sep 20, 2007)

Oh, and you can get test tones from realofexcursion.com's download area.


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