Lucid (or anyone who has real measurements on this) -

I'm thinking about possibly adding some rear speakers, but would only add mid-bass speakers (to keep the proper soundstage). How much mounting depth do I have there? What size speakers can I fit? (ie. 6.5 but with a shallow mounting depth?, etc.)

Thanks in advance!

 

You'll need a very shallow mounting speaker if you use a 6.5, infact you may have to stick with a 5".

 

I am undecided between a couple of speakers one are 5" one are 4" but its the depth. 51mm i know fits someone has done this, but 57mm - will they fit depth wise?

 

I'd PM Lucid about the exact depth.
I'm not sure how many "mm" it is. All I know is that I had to do some trimming to fit the Alpine SPX-137a's that I have in the back.

 

Three aspects need to be considered:

Magnet dia - sub 3.0625"
Speaker chassis SHAPE
Grill design (will it rub the seat?)

You can make other fit like darkknight said, but you'll have to trim some metal. Its 2 sheets of 22 gauge steel there to cut.

Also improve your bass response by baffling the vent (we do this on the systems we sell)

 

That's great info, thanks lucid!

I'll have to see who has mid-bass that fit those specs. I don't want to cut metal. I think kicker has a 6.5" and 8" midbass, obviously the 8" is too big and I've read that people have had better luck fitting in the 4" and 5.25" speakers... I think focal has mid-bass that size... be back tomorrow with more info