Our '76 has an after market Kenwood system added, and is only hooked up to speakers located in the luggage area, which is ok in town but hopeless on the highway, where we have to revert to listening to the side pipes.
Is it worth replacing the 6" X 4" speaker located under the dash and hooking them up as well?

 

Absolutely!

I have 4x6's in the dash and behind the kick panel.

In addition to the 6x9's in the back, the ones in the dash are on the FRONT channel and the ones in the kick panels are on the REAR channel. This hookup sounded the best to me.

I used Infinity speakers.

Side pipes? No problem, just buy bigger amps--it worked just fine with my chambered exhaust--and those are louder usually then sidepipes.

 

I disconnected the dash speakers in the 70s & recently removed them. The kick panel loc. is better. Some 5.25 can be mounted in the kicks properly (solidly mounted w/ a plate) w/o mods to the kick panel. While one would normally want the tweeters near the primary front speakers, the dash location can work very well for tweeters.

Kenwood eXcelon mask CD & 5.25 components in kick panels.
I rarely run the stereo esp. w/ engine running.
The engine makes enough music for me.

 

Today's speakers compared to 1976 speakers is like comparing today's laptop to 1976 main frame. Light years different. I replaced my indash 4x6 and installed a set of 6.5 in the rear I used punch speakers. Sounds like a concert hall. I also installed a $300. (you don't have to spent that much, $150 to $200 will get you a nice setup, not including speakers) indash CD head unit. I did not go w/an amp or sub. No room for those in a C3. Checkout this site www.crutchfield.com

 

I put the amp in the center storage box in the back--fits perfect and central to all wiring.

 

i just installed a sony in dash cd, and infinity 4x6's in the dash. it sounds like do do. i need some 6x9's or something in the rear and an amp. the 4x6's in the dash where a biatch to get fitted. i wish i would have gone the kick panel route now. i'm going to make some corner boxes for the rear similar to the stock location in an 80-82.

 

While perfect concert quality sound is what a lot of most people are looking for , I get from a lot of Corvette owners that they just want to be able to hear the stereo over the road noise and sidepipes with the tops off.

Having said that I really don't think that the amp built into the aftermarket head units will do that effectively. You def want to purchase an aftermarket amp for the front and rear speakers. Head unit power and amplifier power aren't the same so don't let that mislead you.

Rule of thumb always buy the biggest amplifier you can afford that will fit in the area you have to work with and the speaker ratings. And put the biggest speaker in the area that your putting them in. A 5-1/4" speaker will fit in the 4 x 6 underdash location by building a mount to mount them to.

If price is a concern you can check ebay , they have tons of name brand stuff that were 2004, 2005, 2006 models but brand new in the box at a fraction of the price. I'm a big kicker fan and I just bought a KX400.2 last night for $140 shipped. They sell the KX150.2 amps for $59-79.

I personally never run rear speakers on any of my installs, It's usually a subwoofer and the front stage. If your not running a subwoofer you need to put some 6.5's or 6X9's in the rear area to reproduce some kind of bass. A sealed box would be ideal for them but you can mount them to a baffle like the originals were but make sure the everything is nice and tight and no gaps, or the bass will cancel out and you'll hear nothing but high's.

But if your interested in some type of subwoofer that doesn't take up and space check these out:

http://cgi.ebay.com/ebaymotors/ws/eB...5526598&rd=1,1

http://cgi.ebay.com/ws/eBayISAPI.dll...5847041&rd=1,1

http://cgi.ebay.com/ws/eBayISAPI.dll...0328096&rd=1,1

They won't wake your neighbors but will add a nice bottom end to the music and make it come alive. They can mount under the rear deck in 68-77 vettes or on the rear wall of 78-82's

And for a alternative to crutchfield try www.sounddomain.com ......better prices with same level of service.

 

Here's a thread from way back when I detailed my stereo install. You might get some tips from it.

http://forums.corvetteforum.com/show....php?t=1049772

Ganey

 

The real question is "Do you want to listen to music? Or do you want to impress folks with the power rating on your amp(s)?" If you want to listen to music, replace the dash speakers (you will get the mid/high frequency reflection off the windshield and hear the music perfectly well). You can also put kickpanel speakers in to enhance the sound with the Delco head unit. If you really need to kick up the volume and put in big bass speakers, you'll need the extra amp(s) to generate the watts needed for them. If sound quality is the main requirement, replace the head unit (the Delco unit will not generate clean sound).