I have an appointment next week to get the front speakers replaced in my MCS. I'm going to forego an amp for now, but will likely be getting one in the near future when the rear speakers and sub are installed. Here's my question ...

I understand that an amp is required for most aftermarket speakers in order to reach their full potential. But what I don't understand is where in the whole chain the amp plays it's role. Let's consider this:

1) The Boost stereo severely limits bass signal
2) The tweeters/mids in the front recieve the same signal as the woofers, but only output what they're capable of

Would an external amplifier (with crossovers installed) essentially bypass the stock headunit's amplifier and properly route frequencies to their most useful locations (low end to rears, mids / highs to fronts), or does an external amplifier in the Mini just take the stock headunit's final signal and boost it?

I'm a bit of a car audio dunce, but I'm trying to figure it all out. Throw me input if I'm wrong on any of this.

 

An aftermarket amp would bypass the stock head units factory amplifier.

Ideally you would want factory pre-outs from the Head unit into the aftermarket amp. But the mini HU does not have factory pre-outs....so you will want to get a hold of the speaker level outputs as close to the HU as possible...this will mean getting back behind there.

There is tons of info on doing that here...good luck!!

 

How would proximity to the HU determine anything with respect to an amp install? If there are no pre-outs in the Boost unit and you're just tapping speaker level outputs, wouldn't an external amplifier be amplifying the HU's frequency cutoffs?

 

That's something I just don't get. Who thought it was a good idea to cut off the bass to the rears?

If I want to add a sub, I can't convert the rear speakers to 6x9 subs. There's no bass there.

I can't route the rears to the fronts, since the phone only works on the fronts. So if I turn the fronts into the sub channel, I lose the phone audio.

The only logical solution would be to use the fronts and power all speakers with them.

 

Your installed can access the X9931 plug in the drivers side kick panel and tie into there and run the signals to the amp. However to really do this correctly and get a perfect flat responce curve to the amp you need a JL Cleen Sweep or Alpine Imprint.

If you do a 4 channle amp and run 2 channels to the fronts and bridge channels 3&4 to the sub you will never need rear fill full range speakers. Your soundstage will be really good with the fronts and a sub and the Alpine Imprint processor.

 

I will try and find the link...but if memory serve's there is something back that there that resembles un-amplified clean outputs...but don't hold me to this, it may be referring to the HIFI version.

i really don't want to go back there to find out...

 

Maybe I'm getting a little too worked up over this. Depending on the front speakers alone for the best frequency spectrum is absolutely silly, and it bothers the hell out of me that we're forced to do this. MINI puts such emphasis on personalizing our cars, then builds an impassable wall around one of the most commonly personalized parts of a car.

The JL Cleansweep and Alpine Imprint look like viable solutions, but also remove some functionality (fade, stock volume control) according to threads I've skimmed. Plus it's more than I want to spend on this setup.

Am I just overthinking all this? Will I really notice the messed up frequency cutoffs when I have a full front speaker, amp(s), rear speaker, and subwoofer(s) upgrade?

 

Your lower door speaker will get bass. The upper door speaker will either get full range, or midrange and highs (I'm not sure which). If you miss the bass in the rear, and decide not to go with a full amp upgrade, you could do as I did and add a Bass600 or other small powered sub for around $130 plus installation (did it myself). By connecting it to the front channels at the X9331, you can get bass signal for it.

It is unclear to me what the situation is with the rear speakers in 2009 or later. 2007 rear speakers had the bass cut off. Some people with 2009 MINIs claim they get bass in the rear speakers.

My suspicion is that (with 2007 at least) MINI had problems with vibrations in the rear plastic side panels. Instead of fixing the panels, they cut the bass to the rear. This is pure speculation on my part, but I could see how it would happen with trying to get a new model out by deadline.

If you put in an amp, you would probably want to go with something like the CleanSweep option. I don't think you want to do that without an amp.

With the HIFI option, the CleanSweep might not be necessary. If my memory serves, mine had full range for the rear channels at the X9331 connector under the dash. The filtering happens at the rear amp. I'll find out fairly soon, after I do my own install of an amp.

 

if you install a subwoofer you will not need ANY rear fill...fade your speakers all the way to the front and forget about them

 

second that

 

MiniSQ, did you find any unfiltered signals on the rear of the car? Somehow, I think this is only a feature of the HiFi equipped units.