Here is my current setup in my 4dr gsr

front: stock tweeters, a pair of mb quart 6.5 coax's

rear: a pair of mb quart 3-way 6x9's

trunk: 10" Infinity basslink (self-powered 200watt amp/sub)

deck: Alpine 50x5 with two sets of rear out and subwoofer control

My question is, without adding an amp to power the rear or front speakers, would upgrading to aftermarket tweeters make that much of a difference? Keep in mind the 50wx4 deck is already powering 4 high quality mb quart speakers and 2 stock tweeters. Any suggestions would be helpful.

 

I have a similar setup like yours except my front 6.5 are alpines. My MB quart reference components would not fit even with the spacer.(Couldnt close my doorpanel).

You should definately go with an amp. With underpowered speakers you risk the chance of screwing them up. I use a Phoenix Gold ZX450 4 channel amp to power everything. 2 channels for all the speakers in the cabin and 2 channel for my 2 10's. The difference is day and night.

 

I would second the amp...your head unit is more like 12W x 4, and is way underpowering your mbquarts....disconnect the stock tweeters, and run just the quarts.

 

yeah, your deck's power rating is most likely peak power, so most of the time you're probably running something around 15w to your mbs...which isn't a good thing. get a good amp so you can bypass the deck's amp.

 

If you have a set of coaxials up front, you should disconnect the factory tweeter, otherwise it will sound bright, unbalanced and you'll get a confused soundstage. Also, your deck might shut off because just you'll have a 2 ohm (nominal) load above 3kHz or so.

The Quart coaxials will sound sweet in there. I have my 218.61Qs with the tweeter mounted coaxially infront of the woofers and it sounds like it's coming from the factory tweeter- which is disconnected.