Johnny--

If you have an R56 non-HiFi system, I think the votes are in, and the consensus is to (1) replace the OEM 6.5 and 6x9 speakers and (2) swap the channels at the X9331 connector.

If you have a HiFi system, we're still confused.

In either system, if you're going to add a subwoofer, the place to pick off the signals is at the X9331 connector, using the front channel speaker signals; far easier than ripping the dash apart to get to the back of the radio!

 

If your car is a HiFi system please be patient. I am having to take mine in for a amp replacement or a change to something. The dealer promises they can fix it to my satisfaction but i will not know until the 15th of September. After that, IF they have fixed it then i can run new tests.

BTW the output of my amp is really bad so it could be a bad amp or the fact that it is being driven incorrectly. Not sure which at this time.

I just have to wait until i can get the car in for the appointment.

 

I did not order the hifi system with mine.

Will the channel swap compromise the signal in any way? [ie. sound quality/stereo separation]

 

It shouldn't affect the right/left stereo effect, but will reverse the front-to-back, if that matters. The main consequences would be that Bluetooth phone calls come through the rear, and Park Distance Control beeps come through the front.

As far as sound quality goes, the point of the exercise is to send the full range of bass to the larger rear speakers, and the signal that is missing bass to the smaller front speakers. So, it should improve bass response.

 

Yup, as Robin reports -- it sounds better, with the downside that all of a sudden you have a backseat driver (bluetooth, NAV, etc)!

 

Couldn't the signal thats sent to the back be "cloned" to all speakers?

I want to get nice replacements for the oem speakers and wouldent mind the full frequency range up front as well

Plus then all sounds like nav, etc.. will play out of all speakers

no good?

 

By all means, replace the OEM speakers!

At first blush, the idea of sending a full fidelity signal to all speakers is appealing.

But think about it -- what's a tweeter going to do with a signal that has 8 watts of energy around 70Hz? Not much! Same thing with a woofer being fed a lot of energy around 8KHz.

You don't necessarily want the full frequency range at every speaker -- rather you want the full frequency range that speaker can reproduce.

Signals outside of the range a particular transducer can reproduce get turned into heat. That's what crossover networks are for -- only passing energy to the transducer that the transducer can handle.

The synergistic thing about the channel swap is that the 6.5 inch and 4 inch door speakers can't do a lot with low frequencies. But the 6x9 inch speakers in the back certainly can! The channel swap puts the signal with attenuated low frequencies in the doors, where the speakers can't reproduce those frequencies anyway. And the full range signals, including the lows, go to the 6x9 speakers that can handle them.

After I'd replaced front and rear speakers, but before doing the channel swap, I could get some bass out of the system by cranking up the base a whole lot. After doing the channel swap -- I had to turn the bass way down! That energy was now going to speakers that could do something with it!

In the non-HiFi system, I wouldn't try and run everything off the front (full-range) signals, as the amp in the radio can't handle the load.

 

k6rtm,

One problem with the 6x9 producing lots of bass is that the plastics over it are not designed to handle it.
It might get some squeaking. I made and experiment and put there a bass capable driver and it's too much for the plastics.
btw, thanks for the info on the x9331 connector. It was very useful.
Any idea of how to get another pair of speaker wires into the door (for active setup - one pair for each driver)?

Also:
I read you planned to add an amplifier.
I posted on the other thread that you can use the stinger SGN13 adapter to get RCA out.
Another option is to use the harness provided by newministuff.com.
Both appear in previous threads about the subject.

 

bxr510--

I went with a sub (in the boot) so I don't have to really crank the 6x9 speakers, but I haven't noticed any noise from the plastics. Generally, I go with the operating principle that the cross product of critical ear and volume is a constant -- as the volume goes up, I'm less critical!

The X9331 connector saves a lot of wear and tear, that's for sure!

As to the doors, look at the X256 and X257 connectors, particularly the difference between the HiFi and standard systems -- if I read the schematics correctly, in the HiFi system, the 4 inch and 6.5 inch door speakers go to separate connectors in the doors. In the non-HiFi system, the 4 and 6.5 inch speakers are connected in parallel (in the doors) and run through a single pair of pins in the X256, X257 connectors -- and different pins than are used in the HiFi system.

The research project is to dig apart those connectors on both door and car sides to see how populated they are -- do they have the pins needed, or even better, pigtails? Maybe no pins is better, buying pins and pigtailing them to suit would be easier. The ideal is surely to use the connectors, weather covering, wiring, etc., that BMW provided, and not have to run a separate wire across at the door.

I haven't had the spare cycles to do this diging, but I'd like to, as I want to steal the 4 inch speakers for other uses!

 

Not neccessarily true. There are other people that have put 8" sub woofers in place of the 6x9 with a 200 watt amp and have had not problems with the plastics.

This has been stated many time that to get the newministuff conncetor to work you have to take apart 3/4 of the dash to get the connector in place. Why do 1+ hours work to get to a connector when all you need to do is less than 2 minutes worth of work to get to the other end of the same wires.

 

Has anyone taken apart the stereo/speedo? Gotta head back to the university, but I might do that this week while waiting for finals... I'll report back with pictures once I have them.

 

This has already been done. There is a post some where here on NAM.

 

What do you mean by "taken apart"? It takes only a few screws to separate the stereo and speedo from each other: https://www.northamericanmotoring.co...em-stereo.html. I've taken the back cover off the speedo:

 

Alright well I went ahead and started poking around inside the stereo... and I think I found an ACTIVE FILTER!! Trying to poke around and trace some more traces. Here's a picture of the schematic of the filter i found so far. I know it's incomplete, but I'm still working on it.



It's not written symmetrical in order to test myself while drawing it. Turns out it's the same!! Let's see what we can find out...

I still haven't found values for the ceramic capacitors found in the circuit, but I'm working on it... waiting for a friend to bring the heat gun.

By the way, the Op-Amp is an NJM4560 in an SOIC package. Here's the link to the datasheet.

 

The caps are .10 nF or 100 pF

 

I tried this and got nasty results... what will happen if you connect all four speakers to the front inputs is that you'll get phase cancellation and music will sound really weird sometimes.

Don't try it... trust me. Also, while the Clean Sweep does a good job of evening out the hu outputs, it can't recreate frequencies that aren't there... you have to fix the 100 Hz problem if you want excellent quality audio.