I think he's referring to this type of tool/software (or similar): https://www.northamericanmotoring.co...2534-tool.html

 

People have disconnected their HiFi and not had any issues in day to day operation. The only problem is upgrading software at the dealer. The dealer's system first checks the car configuration and verifies that it matches before it will proceed with updating software.

 

Good point Charlie, but what you would change is the filter value to HIFI. Since this is listed as a filter, not the existence of HIFI, it would not affect the radio operation.

And I don't have a direct link to the software. I haven't yet coded the radio as I am waiting for my bluetooth and IBOC modules to arrive. I will post back here how it goes and supply further information.

 

This is all very facinating. I did the swap.

Since then I have installed 4 new speakers in the doors. I have two new speakers waiting to be put into the rear. I have an amplifier but I have not yet figured out how to get the power through the firewall on the passenger side. I'm figuring I am done after that. I might get one of those subwoofers that fit under the seat although they seem fairly expensive and also, the brand I forget, I've had trouble with them. Kenwood I think.

I guess luckily I don't have your ears nor do I play an instrument so I'm a lot easier to make happy.

But what a scientific investigation!

 

Just to clarify on this, are you saying that anything played through the aux jack will have a cutoff below 100 hz for both the front and back speakers or just the back speakers?

 

Not really. If you have a non-hifi or HK system you will have a 100Hz cut off in rear no matter the source.

This is a fixable problem but it is a very involved software setup and you will need a D-CAN programming cable. In a few weeks when I get a chance after I finish my IBOC/HD radio and bluetooth retrofits I will post some of the details about the "secret" radio programing.

 

Sorry perhaps I should fill in some more details. I currently have a set of Focal 165 VR3s running up front off of a Alpine PDX-2.150 amp which gets its signal from the front speaker wires of the X9331 connector connected to a line level converter. I also have a BOSS Audio 600 connected to the same line level converter. Fader is set to full front and I have HiFi.

I have always been leary of the bass put out by this combo, not that it is aweful, but I do have to jack up the bass setting to 4 or 6. For fun I disconnected the line level converter from the H/U and connected the amp and bass600 directly to my Iphone via a 1/8" to RCA cable. I found that the bass was MUCH better. In fact I found that the bass was better with just the Focals running in this setup.

In my test I was listening the first part of Floyd's welcome to the machine and I was I found was that the bass was weakest when playing through my iPhone connected to the H/U via aux jack, better when playing the same song on CD in the H/U, and best when the iPhone was direct connected.

Everything I have seen and tested seems to point to the fact that the stock H/U is pulling bass and I am considering just putting in a way to directly connect my iPhone and bypass the H/U.

I know this is a bit of a hijack of this thread, however it does seem somewhat related.

 

It very well could be related. For your problem, I just don't know the answer, my Stiletto through the aux-in and my factory HIFI setup seems to have plenty of bass with the Tone set at +1. That's good you ran through the troubleshooting.

The only thing else you can check is the AUX-Gain setting. It is the middle softkey when Aux is selected.

Sorry I just don't have any more help.

 

Thanks for the advice, I'll check out that setting.

 

I think that the standard Boost system has the low frequency cut off because of the current limitations of the amp in the head unit.

The standard Boost system doesn't have a seperate outboard amplifier. As such, it drives all the speakers through the head unit's built-in amplifier circuit. This little amp has very limited power and even more limited current flow. Everyone likes to talk in watts per channel but what really drives powerful sound is current flow or AMPS. To illustrate in a very simple manner, take a look at the power cable going into the head unit, I doubt that it is even 18ga wire. A good external power amp will usually run a 10 or 8ga or bigger. This gives you an idea the difference in current flow between the two, like 10x higher current flow.

I believe that in order to avoid over driving this little amp to clipping the decision was made to "limit" the maximum current draw. The best way to "economize" current draw and avoid clipping is to cut back on the big current hogs. 90% of the current flow requirement is to drive the signals below about 200Hz. By running a cutoff to the rear channel below 100hz you can save almost half of the power required to drive your system. Considering that the front channel contributes 75-80% of the "sound value" to the listener it makes sense that you would do your "economizing" with the rear channel.

This is only my considered speculation but it would make sense. Furthermore, by making several of the parameters changeable you can use the same head unit with both boost and hifi systems. If you can access these parameters you can probably restore the full spectrum sound to the rear channel. But this wouldn't address the amplifier power/current issue.

As far as the AUX input goes, I wouldn't doubt that a cutoff filter (20-50Hz) is used in the drive circuit to avoid all kinds of potential problems. The best system performance would most likely come from using the CD player. When I had my system installed we used CD's as the reference and did comparisons to my ipod and usb fob.

 

I've made more progress.
The stereo upgrade is my lowest priority from a sea of
unfinished projects I am currently working on.

Thus, I get to report incrimental changes as I move toward
my eventual goal: make the MINI stereo sound as good or
better than the 25 year old system (speakers 3 years old) I
have in my CRX.

If you recall, a few weeks ago I installed Boston Accoustics
two way speakers in the front (all 4). Once again some improvement
but not leaps and bounds.

This past weekend I undid the "rear speaker swap".

Big difference.

I hope to do the rear speakers and the amp at the same time but
we shall see. Everything seems to take so long.

 

I finally have NCSExpert running, so I'll report back on how the frequency response after changing that setting is. Since the stock stereo will only be driving the high-impedance ADC inputs, I figure it should be fine.

 

BIG UPDATE!!

This thread is a bit old, but I figured I'd resurrect it as I have finally found the tried and true method of fixing this cutoff problem. Thanks to strobeyprobey and his suggestion, I went ahead and modified the radio module's configuration by means of NCS Expert and a K + DCAN cable. This setup will allow you to change many settings in the car, one of which being the stereo's filter settings. From just doing non-scientific "it sounds better" tests, it does seem to be working well. Once I get around to connecting a function generator to the car will I be able to produce conclusive evidence to support the claim.

While I do not encourage everyone to go out and pick up the required cable, I do encourage people who have the cable and software already set up to include this code in their lists and help out others who might need the reprogramming!! As for now, if anyone is in the West Texas area, I'd be happy to help them modify their ECU such that this filter setting is removed.

There is finally a cure!! Yeah!

 

What code? More details!

What module is this in? Is it just labeled RADIO? Also, can the gong sound be changed?

 

If you have NCS Expert set up and ready, the code is VEHICLE_FILTERS in the 2RAD module. You have to change the setting from "r56_stereo" to "r56_hifi".

There are many more settings in the module, even, some that look like you can hard code a volume value onto the gong... I don't have time to mess with it today, but I'll get to it this week! I know that strobeyprobey is also trying to work on the same.

 

I love this thread! Once we have the process nailed down anyone want to go to town on my car in North Jersey/NYC?

 

Sorry, I don't think gong sounds can be changed as it seems they are generated by the vehicle model setting (in our case R56/5/7).

I am very happy you were able to get the filter changed!!!! Since I have the HIFI I don't have the issue, but for everyone running an aftermarket amp this could be a great help.

 

I'm thinking that even though it might be impossible to change the gong sound, it might be possible to adjust the "reference volume" to something too low to hear... who knows, that's what testing is for!

Also, I'm glad that this discovery is helping us standard stereo owners improve our sound systems! It's sort of something that has been bugging me for years! Once again, if anyone in Texas would like to get this or some other modifications done to their MINIs, I'd be glad to help!

 

Fantastic work! Did you say that you were going to do testing to measure the difference? I would love to see those results.

I'm on Long Island in NY, do you know of anyone, or have you communicated with anyone in my area that has this capability? Texas is a bit of a drive for a radio mod.

Thanks,
Dan

 

I am. There's a post around here somewhere where someone took a function generator and put a couple sine waves through the stereo. My method probably won't be quite as through, but for our purposes should be just fine. I'll probably just end up connecting a function generator to the car's aux input and measuring the output before it gets to my DSP. I'll have to take out the seat to get at the inputs, so that will be a project for later in the week.

As for finding someone with a K + DCAN cable, I started a thread in order to get people who are willing to help in contact with others. Check it out here.

 

Looking forward to more of your updates.

 

Not to hijack this thread, but we need you guys to figure out how to repair the H/K amps in the Gen1 MINIs. Any takers?

 

I'd just recommend going aftermarket. Much better sound. I always hated stock head units...

 

The old Gen 1 HK units sound a lot better than anything in the Gen 2's

 

I've never head a Gen 1 unit, so I'm sure that's true... either way, head units now are so darn feature-packed, it makes it worth it to upgrade!