This isn't true. For high power systems, they can and do make an improvement, provided the "big 3" has been done. Having a high output alternator, and upgraded battery will help as well - IF the demand from the stereo requires it. However, capacitors can be a burden on the electrical system if installed incorrectly because the music will keep playing (demand), taking energy from the cap/battery, and the alternator has to restore the energy in two devices rather than just the battery. This is why upgrading the "big 3" is so critical! To summarize, it's all about lowering the resistance with larger gauge wire, allowing the energy transfer to happen faster.

I've described all of this in detail here:
https://www.scionlife.com/forums/vie...153&highlight=

 

^ Totally agree. When implemented correctly and for the right reasons, they're great. I've used them in all my systems for >15yrs w/o issue.

 

yea i'm not sure if i believe they work but i have them from my last system so i figured they couldn't hurt. i want to replace them with a kinetik hc-600, i know for sure that'll do something.

 

I have just enough space to throw a couple backpacks in the trunk, i don't mind, I don't usually have too much to put in the trunk anway.