Looking for someone in the Detroit area (unless someone is willing to send me a radio), who would loan me their BASE radio for testing (or join me while I test it). I'd like to find out the following:

1. How many volts output (power)?
2. How does it behave with a 2 ohm load?
3. Frequency response with FM, with CD
4. Behavior of voltage limiters.

I'll post the data, with explanations here. Testing will be non-destructive, and should take a couple of hours on a Saturday.

 

I can understand testing for items 1, 2 and 4, but I was wondering about 3.

Not so much frequency response with CD’s, but FM. Why worry about what the head unit can deliver for FM. It will be limited to the bandwidth the FCC allows radio stations to broadcast in regardless of the unit’s capabilities.

 

I will be sending tacotim one each of my speakers- the front tweeter and 5.25" midrange/woofer and the rear 6x9.
He will be doing some tests to see how good the stock audio system really is. Objective data rather than subjective ear evaluation would be something worth documenting. I had pulled out all of the speakers to upgrade them.

The other place to inquire if someone might have a stock radio is on Mini2.com

As for evaluation,
#1 and#2 help to determine what speakers might be optimal to use with the stock radio- if one wants to upgrade then what parameters are worth checking for.
#3 Freq resp with radio and CD- to determine the upper limits of range delivered to the speakers. Naturally it may be less or more limited than what is advertised due to less than optimal

If we do this then we can get info that we can't get directly through other channels-like from MINI.USA
Please respond if you know someone that can help. The information will be shared :smile:

 

Many radios deal with noise on weak FM stations by rolling off the high end, while in FM mode (for any signal, strong or weak) Better radios have adaptive filtering that adjusts dependant on the signal. A strong singal is presented with all the bandwidth the FCC allows in the broadcast, a weak signal may be rolled off at 10 kHz. Radios that take the "low road" have attenuation as low as 3 kHz.

I want to understand which category the radio falls into. If it has good power output, could drive a 2 ohm load as long as its not continuous full volume, and has a good tuner, I'd feel less strongly that it needs to be among the first to go. If it has poor performance in one or more categroies, then a radio swap would make a more significant difference.

 

Once my system is upgraded, I will have a HU you could borrow - but probably a month away.
Also beware the standard MINI security system has the radio requiring Kbus data, which means you will need a MINI connected to it :smile:

Maybe you can have the radio switched to security CODE mode while still in a MINI, then sent to you ... but I have not tried this.

 

iancull-
You have a stock radio? I thought you have HK in your mini?

 

Well the, I guess I'm looking for someone in the Detroit area who would come with me to the lab on a Saturday. We would need to remove a door panel to get to one of the front speaker connections. I could do most of the testing on the vehicle. I wouldn't be able to connect four 2 ohm loads, easily.

 

>>iancull-
>>You have a stock radio? I thought you have HK in your mini?

Yes ... HK upgraded system, but 99% certain the HU is identical. I thought tacotim wanted to test the HU, but now I see we wants to test the whole system ...

 

Hi tacotim
I have been told that you can put the head unit in to a service mode (to allow the head unit to be repaired on a test bench). All you need to do is change the security setting from "K bus" to "code". Of course the person who loans you the headunit needs to give you the radio code that came with car manual.

I would love to see test bench results as you can really give the head unit a work out. Plus you can test a lot more things when it is on the test bench and it is less hassle. :smile:

Looking forward to your results

 

That's what the guy at work, who does most of our competitive benchmarking, told me about BMW radios. If someone is willing to put the radio into the proper mode, and sent it to me, I'll test it. It's a lot easier to "bench" test a radio than a whole car (though if I had a whole car with the base system, I'd get a lot more answers)

We'll have to work something out so you trust me to send your radio back. minihune and I worked something out on his speakers. If you're interested, but don't trust me, we'll figure something out.

 

I've got one collecting dust in my garage. Shoot me a PM if you are interested.

R

 

tacotim,

Sorry I can't be of help in this (don't have my MINI yet), but I applaud your efforts and look forward to the results with extreme interest. At this point I'm hoping to build a moderate system off of the factory HU and would love to have some real specs. I'm sure an aftermarket HU would perform better, but I like the factory integrated look of the stock HU and don't want to hassle with MFSW adapters.

Since you are digging this deep into the factory stuff, you might be interested in something I saw on MINI2. I don't have the thread, you'd have to do some searching for it over there; but someone actually pulled the HU apart and pulled the low level signal off the main board prior to the internal amp. With cables and RCA jacks attached at this point, the low level signal was sent to an aftermarket amp. This would be nice, as it bypasses the likely low quality internal amp and avoids the need for high to low level conversion. There were pictures, instructions, and everything in that thread. Check it out if you have a chance; I'd like to know what you think.

Best of luck and keep us posted!

James

PS: You should hook up with Ryephile. He has an audio background and curiosity, and I think he's in Michigan somewhere.

 

This thread on MINI2:
Line outs from stock HU

 

Thank you iancull

I will be sending one each of the stock speakers to tacotim for non destructive testing. (I wonder what destructive testing looks like?) (no never mind- don't tell me)