I want to replace my rear speakers and I'll be getting an Infinity Reference 475a 4 channel amp. I hear that 6x9 speakers can deliver more low than a 6.5 speaker, but suffer quality. Now, I will not be getting any kind of subwoofers, however, I will set up the amp to put only low frequencies to the rear channels. They will act as subs, so any distortion from the oblong shape would not matter as much. I'll try to suff the amp behind the rear panel in one of those cubbies, but it is a huge amp. I need to make a mock-up.

On to the question, should I get another set of 6.5 Infinity Kappas and only use the woofers (wasting the crossover circuitry and tweeters) or get 6x9 2-way Kappas (which will only get low frequency - what will happen to the tweeter with lows?)

6.5 speakers fit back there, right? Is 6x9 too big? Infinity makes 5x7 as well.

I do not want car rattling, chest thumping bass, only full, clear sound.

 

I'm confused . Have you thought about putting an 8" sub back there? Someone here did it with a nice write up since all you want is the lows.

 

Will those fit in the stock rear speaker location?

 

You could probably fit a shallow-mount 8" there with some modification to the factory mounting hole.

The problem with using full range speakers primarily for bass is that they're not really designed for that use - it's kind of like using summer tires in the snow. Good speakers like Kappas will put out some decent bass on their own IF you feed them enough power, but they'll be working overtime to really sound decent. Now I'm not sure how the acoustics in a MINI are (yet), but I can imagine it's not exactly a quite concert hall in there... My Porsche is exactly the same way, and I find myself having to push my system when I'm at highway speeds. Now I know where you're coming from because for the longest time I was totally against subs and the obnoxious bass I associated them with. But the simple facts are that to get full, rich sound at speed, you need a dedicated low frequency driver. I have Polk components all around, and even getting 141w RMS each, they still can't really put out the low frequencies I need. I ended up getting a small powered sub and concealing it in my spare-tire well.

Just some food for thought.

 

The stock rear speakers are 6x9 (6.5 for the cabrio).

 

You may want to look into 6.5 inch subs for the rear. Both JL Audio and Elemental Designs make them, and they will fit (although you may want to consider using small enclosures to house them rather than running free air). Your Infinity amp is slightly underpowered to drive them (at 2 ohms), but it sounds as though your just looking to round out the bottom end and not much more.

 

Too be clearer, I want to make a soundstage with highs and mids up front and the bass from behind. The stock system had almost too much bass for me. Adding the speakers was to improve sound quality. So if running 6.5 subs in the rear spots in free air will provide at least the same levels of bass as the stock system, then I will be plenty happy with that.

 

Tang Band (you can find at partsexpress) makes a 6"x9" subwoofer that is supposedly very good for what it is.

I went the modification route with 8" subwoofers. Cutting the sheetmetal with a jigsaw and sheet metal blade is how I went about it. There are many more choices for 8" subwoofers.

 

http://www.crutchfield.com/g_520/Component-Subwoofers.html?tp=111&nvpair=FFSize|[rank1]6-1%2f2%22

There's a couple 6.5" subs. I agree with m3ntal that there are a lot more options in 8", so if you don't mind a bit of cutting I'd look into that. If you're concerned about excessive bass, I'd still bias my choice to a larger driver and just plan to keep the gains down. Better to find yourself with too much bass than not enough, because you can always turn the gain down. Just make sure you check to see what your maximum mount depth is... I can't imagine there's much more than 4" to play with in the rear location there. Chilisport also brings up a good point with the enclosures - your bass will be a bit tighter sounding, and less boomy. I'd look into if you're going for good sound quality.

 

I had a similar goal as you and I replaced my rear 6x9 with these CDT Audio CL-69 and I am very happy...
http://www.woofersetc.com/index.cfm?...roduct_ID=3077

I made sure to close in the cavity behind and install much sound deadener to reduce the chance of any rattles... Happy with the results

 

Would speaker baffels accomplish about the same thing as a sub box? I used speaker baffels in the front in order to protect them.

I have yet to use any sound deadening material. Will it really do what everyone claims it does? I have no rattles or squeaks in any panels by the speakers, but that might change when I get the amp.

I'm beginning to think that I may have to sacrifice some of my trunk for a sub box with Kappa Perfect subs, the Infinity Basslink, or the Blaupunkt THb 200A. I really do want crisp, clear sound with tight bass that does not resonate or shake the car - I hate feeling bass vibrations in my body. But sound quality is paramount, you might also notice I like Infinity.

 

I put the elemental 6.5 woofers in my 6x9 holes. I have to turn the amp down they put out so much bass. Easy to install. Driving them with about 120 watts each.
My opinion is they sound tight and fast, they have never sounded boomy. They will however rattle the car if turned up. I sealed the 6x9 cavity with sound deadener. Made sure I had new clips for the panels.

A pic
http://picasaweb.google.com/usafDan/...41893527092962

Link to sub
http://www.edesignaudio.com/product_...products_id=33
At 65$ a pop not to bad for the bass they put out, plus they take up no space.

Just a suggestion.

 

Do you have any sort or drawings or plans for those mounts? I have a lot of MDF left over from my front speaker mounts.

Did you just use regular dynamat in the cavity?

 

Just regular 1/2" plywood. I cut the hole for the woofer first then I started cutting the plywood in smaller and smaller rectangles until it fit, just trimming a little off each time. Once it fit flat I marked the holes for the 6x9 on the ply then drilled and installed t-nuts. If I remember right it came out to about 7x10 with the corners of the ply cut at an angle. Once you get the first one done the second is just a copy. I then mounted the woofer to the ply, with t-nuts, then slid the whole thing into the cavity and mounted it. The black foam you see between the ply and sheet metal of the car is speaker gasket. Use thread lock on the t-nuts. I used the ice stop stuff from lowes for the sound deadener, it's in the roofing section.
Not hard to do if you just take your time. Plus if you mess up your just out a little piece of ply or mdf.