Wheres a better spot to mount component tweeters...on the doors near the vent or on the A-pillars?

 

in the vent

 

what about dash mounting?

 

As long as we're talking non-stock locations, under-dash horns are in a close race for the kickpanels for the best place to put tweeters. Unfortunately kickpanels are not audio friendly due to the location of a fuse box and the crash pads are already too low. Next-best is as far away as you can get the tweeters from your ears without using the dash and windshield as horns. A pillars.



Unless you have a fancypants digital delay setup, then you can put them wherever and tune the car so it sounds right for (only) one occupant.

 

Personally I think the stock location is best.

A-pillar may be to close to your head and pillar pods enlarge the blind spot depending on location.

If you mount it in the vent you lose the vent.

I think under dash or kick panel is way to low.

If there is a noticable horn effect exerted by mounting between dash and windshield it may be desirable as all occupants heads are usually at a similar height.

By the way: Most JVC radios can be adjusted for several seating positions. I think that is not a fancy extra anymore. It does lead to noticable sound differences and I would advise anyone to get radio with that.