Installing speakers

Dataz722

Original poster
Member
Dec 29, 2012
7
I just got a 2007 Trailblazer LS (non bose) a few days ago. Only one of the speakers works reliably and even then of course sounds terrible. I have a pretty old set of JL speakers sitting around from a car that I wrecked quite a few years ago and I want to put them into the TB. One set is 5 1/4 and the other JL says is a 6 1/2. The ones that are 6.5 crutchfield has listed as actually a 6.75 and says that they won't fit most 6.5 openings.

First, do you think these 6.5 speakers will even fit? And second, would you put the smaller ones in the front or back. I am used to normal small cars that the larger speakers are in the back panel but in the TB with them all being in the doors should I just have the big ones up front with me?

Also, it does not have the bose system but it does have the spots for the 3.5" speakers on the dash. If I were to install speakers in there is there a reasonable way to hook them up to the factory HU? Or would I be better off waiting until I finally replace the HU?


Thanks.
 

Ed H

Member
Oct 18, 2012
167
I would pull the door panel and give them a test fit. I had to use a dremmel to cut out some of the plastic that surrouded the woofer to install 6-1/2 earlier today. I will take a few pics tomorrow when I install the rest. I can't imagine why 6-3/4 would not fit - if you own a dremmel.

Larger speakers up front, with the rears adding 'fill'. That is my vote. Works well when you get the sub too.

If you buy components, you can put speakers in the dash. Or wire them in parallel with the existing speakers. Why not.. :smile:
 

ConeKilrAutoX

Member
Dec 8, 2011
1,179
Dataz722 said:
I just got a 2007 Trailblazer LS (non bose) a few days ago. Only one of the speakers works reliably and even then of course sounds terrible. I have a pretty old set of JL speakers sitting around from a car that I wrecked quite a few years ago and I want to put them into the TB. One set is 5 1/4 and the other JL says is a 6 1/2. The ones that are 6.5 crutchfield has listed as actually a 6.75 and says that they won't fit most 6.5 openings.

First, do you think these 6.5 speakers will even fit? And second, would you put the smaller ones in the front or back. I am used to normal small cars that the larger speakers are in the back panel but in the TB with them all being in the doors should I just have the big ones up front with me?

Also, it does not have the bose system but it does have the spots for the 3.5" speakers on the dash. If I were to install speakers in there is there a reasonable way to hook them up to the factory HU? Or would I be better off waiting until I finally replace the HU?


Thanks.

I believe the 07 TB has 6 1/2 front and rear so if its truly a 6 1/2 speaker (on the mounting side) it should work I assume. and the TB can take a depth of like 2" maybe 2.5' I'm not sure on that though with the 06 and up I knew on the 03 years it was really close with a 2.5" Like Ed H said, you could somehow get them to fit.

As for the 3.5 up front I would say you might be able to tap the front speaker lines leaving the HU. (Tap the Front Left +/- for the left 3.5" and Front Right +/- for the right 3.5") if its just temp. until you get a new HU ?

I ran tapped speakers like that for 6+ months until I got around to installing my HU and I had no problems. It might obviously take away some power to the front door speakers since the HU only puts out so much wattage per channel/speaker but I would imagine that you'll have sound from the 3.5's to help even that out. I know its not the best way but it should work.

hope I helped and didn't give you lousy info...I just know I had done it that way and it was ok for me when I used to have the stock HU.
 

Dataz722

Original poster
Member
Dec 29, 2012
7
Ed H said:
I would pull the door panel and give them a test fit. I had to use a dremmel to cut out some of the plastic that surrouded the woofer to install 6-1/2 earlier today. I will take a few pics tomorrow when I install the rest. I can't imagine why 6-3/4 would not fit - if you own a dremmel.

Larger speakers up front, with the rears adding 'fill'. That is my vote. Works well when you get the sub too.

If you buy components, you can put speakers in the dash. Or wire them in parallel with the existing speakers. Why not.. :smile:

Thanks. I didn't know if that would cause an issue with residence or whatnot.

And yeah I have a dremel. I didn't know if there would be enough material to be able to shave off enough to get it to fit.

ConeKilrAutoX said:
I believe the 07 TB has 6 1/2 front and rear so if its truly a 6 1/2 speaker (on the mounting side) it should work I assume. and the TB can take a depth of like 2" maybe 2.5' I'm not sure on that though with the 06 and up I knew on the 03 years it was really close with a 2.5" Like Ed H said, you could somehow get them to fit.

As for the 3.5 up front I would say you might be able to tap the front speaker lines leaving the HU. (Tap the Front Left +/- for the left 3.5" and Front Right +/- for the right 3.5") if its just temp. until you get a new HU ?

I ran tapped speakers like that for 6+ months until I got around to installing my HU and I had no problems. It might obviously take away some power to the front door speakers since the HU only puts out so much wattage per channel/speaker but I would imagine that you'll have sound from the 3.5's to help even that out. I know its not the best way but it should work.

hope I helped and didn't give you lousy info...I just know I had done it that way and it was ok for me when I used to have the stock HU.

I had read somewhere, can't remember where, that the doors had a mounting depth of 3". I sure hope hat is right though since these are 2.5".
 

Ed H

Member
Oct 18, 2012
167
Dataz,

I just finished my Polk DXI650 install today and snapped a few pics that might save you some time.

Below is the stock non-Bose speaker. I am holding up the dust cover than does not get re-installed (at least not with my speakers).
View attachment 25647

I had to remove some of the plastic shown in this pic because the Polks have a different shape than the stockers
View attachment 25646

Same here - need to remove some plastic to get the speakers in.
View attachment 25648

This is the speaker mount after modification with dremmel - that plastics stinks when you cut it.
View attachment 25649

Here is the new speaker in place.
View attachment 25650

Depending on the shape / size of your speaker frame, you may have to remove material at 2 o'clock in the last photo to get it to fit - in addition to widening the speaker opening a little more. 1/4" difference in size is only 1/8" per side, so that shouldn't be too bad. There is plenty of each space to get the screws in (see 3rd image). Let us know how it goes!
 

Attachments

  • P1050038.jpg
    P1050038.jpg
    59 KB · Views: 13
  • P1050036.jpg
    P1050036.jpg
    53.8 KB · Views: 16
  • P1050037.jpg
    P1050037.jpg
    49.8 KB · Views: 10
  • P1050050.jpg
    P1050050.jpg
    52.4 KB · Views: 16
  • P1050053.jpg
    P1050053.jpg
    61.7 KB · Views: 14

Dataz722

Original poster
Member
Dec 29, 2012
7
Wow! I forgot how great those speakers sounded. I really used to love them and I do again. I only installed 2 of them, one each front and back. It was by far the most difficult or at least pain in the ass install I have ever done. Crutchfield was right and those speakers were too big. I had to remove quite a bit of material to get them to fit but I got it in. Making the mount for the back one really sucked too but a handful of self tapping screws really helped. Thanks for all the advice, I can't wait to find time to get the other two in.

I think I am going to have to come up with the money for a head unit and an amp sooner than I had planned. :crazy:
 

Dataz722

Original poster
Member
Dec 29, 2012
7
Thanks for the pictures Ed, I wish I could have gotten away with removing as little as you did.
 

02Olds

Member
Dec 29, 2012
91
Personally, I'd tell you to put the 6.5" in the front and 5-1/4" in the back, for two reasons in particular:
-The front is your stage! You sit in the front, so reap the benefits of the larger, more output speakers.
-The fronts are made to accommodate larger speakers without as much modification, I.E. the Bose systems. (6.5 front, 5-1/4 rear stock)

5-1/4" speakers should be direct fit for either front or back, and depending on the mounting diameter, the actual diameter of the back of the speaker itself, the 6.5" may be able to fit in without any modification for the holes except putting new screw holes in, as what really matters is whether the speakers can fit in the holes themselves, not the outer diameter of the speaker. I don't know if this is difficult to understand the way I put it, but think of it this way... A 12" sub is 12" diameter total, meaning from edge to edge on the outside, but if you try to mount it in a 12" hole, it will simply drop through. It needs a lip to sit on, meaning a smaller hole than the size of the speaker itself. Each speaker can fit into a different size hole, so just test your boundaries, and if a dermal is needed, open it up to the desired dimensions.

Hope I helped... I'm not the most knowledgable person in the world, but I've done a few systems for myself and friends, so I have a tiny bit of know-how.

Good luck, enjoy the new ride, and keep us updated on the install!
 

Forum Statistics

Threads
23,229
Posts
637,063
Members
18,390
Latest member
jgriff

Members Online