What's happening to my Klipsch speakers?

[Kain]

My home theater consists of the following:

Display: Panasonic TH-42PW5
DVD Player: Harman Kardon DVD 30
A/V Receiver: Harman Kardon AVR 8500
Mains: Klipsch RF-7
Center: Klipsch RC-7
Surrounds: Klipsch RS-7
Subwoofer: None (Seaton Sound SubMersive on order)

I setup my home theater back in 2004 and haven't made any changes to the setup or my room. I have found that my speakers sound more brighter/harsher than they use to. Maybe I've just become more sensitive to higher frequencies, I don't know. I've narrowed it down to the speaker cables which are 5 years old now. Do speaker cable degrade over time which could cause the brighter/harsher sound?

I've also asked this question on the AVS Forum and was recommended to try a high-powered amplifier as the RF-7s dip down to 2.8 ohms at certain frequencies (I think it's between 40-100Hz) which can cause clipping and harsh upper frequencies as a result. However, I'm running all speakers as "small" with a crossover of 80Hz so clipping should be at a minimum even if it is actually happening. But then, during portions in music where there are no bass frequencies to cause clipping (only high frequencies) it still sounds a bit bright/harsh.

What do you guys recommend? Try a high-powered amplifier, new cables, and/or simply new speakers? I live in Dubai where you cannot audition stuff at home so trying a new amplifier without buying it will be most likely impossible.

I've been eying Dynaudio speakers which are well-known to be very neutral however I might miss the dynamics of Klipsch speakers.

[tonyvdb]

On your HK receiver does it have some sort of auto room correction calibration? Did it get turned off/on by mistake recently? It could be a night mode setting got accidentally turned on as well. Speaker cables will not make that kind of difference and buying new cable (unless its to small) will not improve it.
Check the backs of the speakers to make sure that the wire is secured properly, are the Klipsch RF-7 bi amp-able if so check the jumper between the posts to make sure it is not loose.

[Kain]

My A/V receiver has no auto room correction/calibration (it's an older unit). All other settings are the same (I've checked them and I am the only one who really uses this home theater). The speaker cables are all secured properly.

[tonyvdb]

Hmmmm, It is possible that your receiver is starting to fail do you have any other way to test the speakers on a different amp? If your receiver has pre outs then adding an external amp would certainly help.

[hjones4841]

I doubt that you are running out of amp power - Klipsch speakers usually require a lot less amp power than other brands (higher efficiency). I agree that speaker cable ageing is not an issue, barring severe corrosion on the connectors.

It could be ageing of the capacitors in the crossover, but, then again, at 5 years old, I would not expect that. Klipsch used to use clamping diodes and fuses for tweeter protection, but that was many years ago. The clamping diodes could cause harshness, but of course with blown fuses there would be no sound from the tweeters.

Klipsch has a great forum here:

http://community.klipsch.com/forums/

I suggest that you post over there - there are very likely others that have the same speakers that you could compare notes with.