One speaker putting out -3db less?

One of my speakers is playing around -3db less than the other. I switched the speaker cables to make sure it wasn't a channel in my amp. This just recently started. I also turned my sub off when I checked it. I used a spl meter to do so. My amp is a B&K reference 200.2 and my speakers are Paradigm Studio 40 v4. Any ideas what can be causing this? My speaks are only 2 years old and I do occasionally crank them, but never all the up.
While it certainly sounds that one of your speakers is at fault, it is worth a try to unplug all of your digital equipment for a minute or so, then power back up to see if this problem resolves. A current spike may have fooled your digital equipment into thinking it is using more power in one channel vs another, and it may have attenuated the signal in trying to manage it. Because you switched speaker cables and the volume of one speaker remains attenuated, this may not help, but is worth a try.
Where are you putting the spl meter? What type of test signal are you using? A 3dB difference at the listening position could be easily caused by the room. Switch the speakers and see if you get the same results.
At what frequencies does this 3db loss appear? As Herman suggests you might just have a difference caused by boundary reinforcement unless the loss is across the bandwidth. Also, are you getting a substantial shift in the center of the soundstage to the stronger speaker? Or do you must detect it with the sound meter and in the frequencies 500hz or lower?

The best way to measure the speakers, if you are not already doing so is to put the meter about three feet in front of the center of each speaker and chart the results there as opposed to the listening position.

You can refine this further to identify which driver is failing, if it is, by measuring each driver with the mike right in front (a couple of inches) of each driver and charting the results. Be sure to use a secure stand. This is not a 'hand held' procedure.

Move the speakers to the center of the room when you to your test. Are your speakers bi-wired? You can also check upper and lower frequencies left to right to narrow down a problem.
Are the speaker cables the same lengths?
These are all great points. I used a handheld spl meter in the center and moved my balance left and right.It's a noticeable difference. I noticed my soundstage had moved slightly to the left, particularly the vocals, that's what caused me to check it. I'll do a orw thorough check later tonight. Also, don't know if this could have done something, but I've suddenly had a terrible static issue. I grabbed my speaker a couple of tims now to adjust it and been shocked to the point it sounded like my cd skipped.
The speaker cable length, if different, is inconsequential.
You need to use white noise to test and mono if playing music.

Look for a tweeter that is not working.

Make sure the connectors are all clean and tight.

Use contact cleaner and clean the volume and balance controls. Shut off power and twist knobs multiple times.
If you've had "terrible static", definately unplug all of your equipment, wait a minute, and plug it back in. You might be quite pleased with the result.
04-13-10: Audiofeil
The speaker cable length, if different, is inconsequential.
Audiofeil (Threads | Answers)

Likely right, but there could be a difference, if slight, depending on the length discrepancy and cable specs. Being a forum and asking for advice, I'll chalk it up to 'covering all the bases'.
My speaker cables are the same length. And as far as room boundaries, these speakers, and everything else, have been in the same spot for almost 2 years. I used a Blue Sky calibration disc.

40-80hz I'm almost dead even.
500-2.5hz there's a huge difference.

I hope I haven't huffed a tweeter. My local Paradigm dealer quit carrying them a couple of months ago. Any ideas where to get parts? This is a very unwelcome developement.
Thanks again for everyones help.
Yeah that is rough. I have been though this a few times. It has always come down to upstream equipment for me (preamps mostly). But is sounds like your speaker may be the problem.

I would switch location (right for left) of them and retest just to make sure you are not getting room gain. But the frequency seems to high to be room gain unless the louder speaker is very close to a wall etc.
I've moved them all around, changed channels, changed sources, chnged cables and everytime it's the highs in one speaker. Found a local dealer to get me a replacement, just have to take him an invoice since the dealer I bought them from doesn't sell them anymore. The difference at 50-2.5hz was about 9db. Thanks for all the input.