[taibanl]

Primarily looking for input from those with DIRECT experience or knowledge.

I am forming a hypothesis that the HiFi configuration is not everything it's cracked up to be. While we (me-in my sticky) advocate recoding to HiFi as an optimal or near-optimal solution, I am beginning to lose faith that that is the case in the e90. While the HiFi signal quality is flat - which is its primary benefit, it may not be as good as other alternatives. In support I'll offer the following examples

Technic - JL HD install on customer's car, recoded to Hifi, noted that 'something was missing' in terms of SQ.

BMW325i-replaced HiFi system with aftermarket and noted improved SQ

VP electricity - noted that when he switched from HiFi to DA2, the SQ jump was immediately noticeable.

Other posters have also suggested better SQ from aftermarket HU.

Taibanl - Its been nearly two years since I went from a 'stereo' coded system to HiFi. While I also made other changes at the time (JL XD --> HD), I think i had a better quality (explanation forthcoming - be patient) signal in the old configuration. I have never had the same SQ from my existing setup which is easily 3x-5x the price as my old setup. I think this is due to the SN ratio.

The MS-8 has a slightly better SN ratio with use of the low-level inputs vs the speaker inputs. However, that SN ratio only applies to the relevant signal that it receives. In my case, having gone from speaker level in to low level, I think the SN ratio is worse. That is to say that I think the SOURCE SN ratio is better in stereo than it is in Hifi.

It is well documented that speaker signals (AC?) are better shielded from noise than low-level (DC?) <--may have that backwards. Andy Weymeyer has a discussion on DIYMA why RCA's should be abandoned for speaker outs. It's really the OEM curve's that are the problem - not the speaker outs?

So I think going to HiFi may have actually been the source of my SQ issues currently. While I had some background noise before, I have a much louder noise floor now (also have more power) but more importantly, the Mid to treble range just does not sound anywhere as clear as it used to. Vocals aren't pristine anymore and other music doesn't 'surround' me as it used to. (Not a fan of electronica but it sounds GREAT in a fully working MS-8 system).

There are other possibilities of course:

• HD not as good SQ as XD (unlikely),
• MS-8 defective (or damaged in the configuration change) (plausible but tuning active still sounds much better than tuning defeat so, also unlikely)
• Issue with my 'custom' center speaker - (maybe but think there are issues beyond this bc I also notice the same SQ/mild distortion with vocals with L7 processing off).
• Louder system=more reflections=less SQ? (doubtful as it doesn't seem to sound as good at any volume).

Im sort of convinced I should have left it in the stereo/speaker level in configuration...but maybe I am out to lunch?

Thoughts?

[bmw325i]

I suspected this since I switched out my headunit, but there are too many variables for me to say for sure.

If I had USB with the stock headunit it would have been a fairer comparison.

Also I removed the ms8 when I switched out the headunit. I had my rear speakers and center powered by the ms8, the front speakers and underseats were powered by the xd600/6. After changing the headunit I just have my front door speakers and underseats powered by the xd600/6 and all other speakers are disconnected.

Here are a few things you can try:
1. Replace the headunit. You'll get alot more features anyways and you can use any amp or sound processor without having to worry about balanced inputs.

2. Get a more powerful amp. When all 6 channels on my amp were working I had my Morels bridged and the sq was much better with 150 watts than with 75 watts. I realized that headroom is one of the most important things in sq. My reasoning for this is if you have more power than your speakers can handle they will blow before the amp starts to clip. It will get much louder than you can tolerate anyways so you'll never turn it up to the point that you blow your speakers. I still haven't replaced my amp yet, but I am planning on getting a PDX F6, possibly 2. I like that it does the same power at 4 ohms as it does at 2 ohms.

3. Get rid of the ms8. Even using the aux in on the ms8, sq wasn't very good and midbass was always an issue for me. I think the ms8 is part of the problem. The ms8 has 2.8 volt outputs and a good aftermarket headunit should have at least 4 volt outputs so that might be the reason for the difference in sq.

[TMR]

I switched from the DA1 / DA2 and tried the hi-fi output and switched back to the DA1 / DA2.

[Quasimodem]

Well this thread prompted me try my bypass for my Iphone to compare it to the quality of my Y-cable setup.

My e90 came with the basic stereo system for the US, I removed the wires carrying the Head Unit rear channel balanced signals (no gongs or cell phone audio) from the connector going into the stock rear amp. I adapted them with some Kicker KISL wire-to-RCA adapters (because audiocontrol seems to think that balanced signals are normally transmitted through RCA cables and not twisted-pair) and added a five-foot RCA cable extension plugging into my Audiocontrol Matrix line driver's inputs. I set the inner pins for "balanced" inputs. The four outputs for FR, FL, RR, RL of the Matrix go to my 4 Channel amp and the outputs on that amp go to my subamp. That's my basic setup.

So now I spliced into two cables going into my Matrix with two Y-cables. I connected one side to the same Head Unit rear channel line outs that were hooked up before, and hooked up the other side to and adapter for my Iphone's headset output (I did have to turn up the amplification on the Matrix because the Iphone doesnt output much power).

Results: There does seem to be a quality difference, with the stock HU signal being much more "boomy" and stronger at the lower frequencies. Now there may be something going on in my line driver that is causing the problem. Or my wiring may be messing up the balanced signal so the Matrix is not recompiling it properly. I need to experiment more, the first thing I will do is to change the pins in my matrix to unbalanced, then take the matrix out totally (though my amps dont say they can interpret balanced signals).

[taibanl]

Originally Posted by bmw325i

Here are a few things you can try:

2. Get a more powerful amp.

3. Get rid of the ms8. Even using the aux in on the ms8, sq wasn't very good and midbass was always an issue for me. I think the ms8 is part of the problem. The ms8 has 2.8 volt outputs and a good aftermarket headunit should have at least 4 volt outputs so that might be the reason for the difference in sq.

As you know - I went UP from the XD to the HD - 150wpc now vs 75 before (when it sounded pretty amazing)

By the same token the MS-8 has served me well; a PITA to tune, no doubt, but I have had amazing results with the MS-8 and lesser equipment. I don't have mid bass issues but I know how to tune this thing better than most (and I don't always have luck on first attempt).

Hence the reason I am suspecting the output configuration.

[bmw325i]

Originally Posted by taibanl

As you know - I went UP from the XD to the HD - 150wpc now vs 75 before (when it sounded pretty amazing)

By the same token the MS-8 has served me well; a PITA to tune, no doubt, but I have had amazing results with the MS-8 and lesser equipment. I don't have mid bass issues but I know how to tune this thing better than most (and I don't always have luck on first attempt).

Hence the reason I am suspecting the output configuration.

Is that 150 watts at 4 ohms? It doesn't make sense that the HD doesn't sound as good as the XD. Maybe the balanced signal has something to do with it.

[taibanl]

Originally Posted by bmw325i

Is that 150 watts at 4 ohms? It doesn't make sense that the HD doesn't sound as good as the XD. Maybe the balanced signal has something to do with it.

Right. It should sound better. So im suspecting the low level outs (used speaker level outs with XD- signal correction with MS-8). You know what they say. If it aint broke...

[cdgatti]

I agree - and don't have measurements to back it up, but our hifi systems just don't have that nice clarity that you hear with other good car stereo systems. Maybe it is the hifi signal and maybe it's bad cabin acoustics, who knows.

I can't do anything about the cabin acoustics so am looking to install an alpine pxa-h800 in the chain. Figure break down the hifi analog to digital then have a good DAC convert it back to analog to feed my amps and morels, that should improve it, plus gain all the equalization and time delay capabilities... that's my plan anyway.

[taibanl]

Originally Posted by cdgatti

I agree - and don't have measurements to back it up, but our hifi systems just don't have that nice clarity that you hear with other good car stereo systems. Maybe it is the hifi signal and maybe it's bad cabin acoustics, who knows.

I can't do anything about the cabin acoustics so am looking to install an alpine pxa-h800 in the chain. Figure break down the hifi analog to digital then have a good DAC convert it back to analog to feed my amps and morels, that should improve it, plus gain all the equalization and time delay capabilities... that's my plan anyway.

Right but consider (if my theory is correct) MS-8 is doing that same A/D - D/A conversion and still has issues with HiFi signal. Garbage in - Garbage out still applies. You can have all the S/N ratio you want, but when noise becomes part of the signal, then it will be ever present.

Time alignment is working just fine in my car, I have good imaging. Its audible distortion in the audio.

[bmw325i]

I still think replacing the head unit is the answer. As long as you relocate the head unit to the trunk and use the connects2 harness everything will work as it should, even the steering wheel controls. Plus you could get navigation and a rear view camera which are very useful.

[cdgatti]

bmw325i is there a harness available for the head unit relocation? Can't find a good write up of this procedure.

[taibanl]

Originally Posted by bmw325i

I still think replacing the head unit is the answer. As long as you relocate the head unit to the trunk and use the connects2 harness everything will work as it should, even the steering wheel controls. Plus you could get navigation and a rear view camera which are very useful.

I am warming up to such a solution....

[bmw325i]

Originally Posted by cdgatti

bmw325i is there a harness available for the head unit relocation? Can't find a good write up of this procedure.

No, but you should use the connects2 harness for the aftermarket headunit, and the metra harness for the stock headunit. Tap the can wires off the connects2 harness and extend them to the metra harness in the trunk. You can use the power and ground from the stock amp, and use the MOST cables from the amp or the factory Bluetooth. You need to use a most loop for the cables in the dash.

Chimes and pdc are the only problem on amplified systems. You'd have to have a seperate non-amplified speaker just for the chimes, I guess you could always use the center channel for that. Early e9Xs already have a seperate speaker for the chimes, so I'm not sure if its possible to retrofit one.

[bmw325i]

Originally Posted by taibanl

I am warming up to such a solution....

If its done right you'll get no errors, and the dealer will still be able to connect to the car. I still haven't relocated mine and I don't have any problems. Then again I've never taken my car to a BMW dealership and I didn't have any options that use most other than logic 7.

[cdgatti]

Originally Posted by bmw325i

No, but you should use the connects2 harness for the aftermarket headunit, and the metra harness for the stock headunit. Tap the can wires off the connects2 harness and extend them to the metra harness in the trunk. You can use the power and ground from the stock amp, and use the MOST cables from the amp or the factory Bluetooth. You need to use a most loop for the cables in the dash.

Chimes and pdc are the only problem on amplified systems. You'd have to have a seperate non-amplified speaker just for the chimes, I guess you could always use the center channel for that. Early e9Xs already have a seperate speaker for the chimes, so I'm not sure if its possible to retrofit one.

I assume those instructions are for a logic 7? For a stock hifi system how would I modify?

[bmw325i]

Originally Posted by cdgatti

I assume those instructions are for a logic 7? For a stock hifi system how would I modify?

Basically the same. Take a look at this thread.
http://www.e90post.com/forums/showthread.php?t=319976

Use the Connects2 harness instead of the Metra 70-9003. Extend pins 9, 11, and 15 from the Connects2 harness to the metra harness. Ground the stock head unit to the factory grounding point in the trunk. Use the most cables from the factory Bluetooth, or satellite radio. You still need the most loop even if you don't have logic 7.

If your still using the stock amp get RCA to speaker wire adapters like the thread below, or replace the amp and use a normal RCA cable.
http://www.e90post.com/forums/showthread.php?t=809490

[cdgatti]

Thanks but I am still missing something here. If I connect to the harness in the dash to run the wires to the harness and radio in the trunk, what harness in the dash will I connect the new radio to? Thanks and apologize for not getting it, but I have a feeling am not the only one.

[bmw325i]

Originally Posted by cdgatti

Thanks but I am still missing something here. If I connect to the harness in the dash to run the wires to the harness and radio in the trunk, what harness in the dash will I connect the new radio to? Thanks and apologize for not getting it, but I have a feeling am not the only one.

Use the connects2 harness for the aftermarket head unit. You just need to tap the power and can wires. I reccomend soldering and heatshrinking all connections, and cut all your wires to length so it's neat.

[cdgatti]

Originally Posted by bmw325i

Use the connects2 harness for the aftermarket head unit. You just need to tap the power and can wires. I reccomend soldering and heatshrinking all connections, and cut all your wires to length so it's neat.

Ok so in terms of harnesses, I need the metra 71-9003 and a metra 70-9003 (or connects2 equiv) and a connects2 harness (for new radio), for a total of 3?

[bmw325i]

Originally Posted by cdgatti

Ok so in terms of harnesses, I need the metra 71-9003 and a metra 70-9003 (or connects2 equiv) and a connects2 harness (for new radio), for a total of 3?

You only need two harnesses. One plugs into the stock connection in the dash(connects2), and the other plugs into the stock head unit.

[mathematics]

I think he is confused because once you extend the factory dash harness, you no longer have a harness to connect the aftermarket harness to. Correct me if that is wrong.

What you do once you have that harness in the dash connected for the extension to the trunk is splice into the harness to get power and ground and all that for the aftermarket deck. That's why the splicing and heat shrinking was mentioned.

[bmw325i]

Originally Posted by mathematics

I think he is confused because once you extend the factory dash harness, you no longer have a harness to connect the aftermarket harness to. Correct me if that is wrong.

What you do once you have that harness in the dash connected for the extension to the trunk is splice into the harness to get power and ground and all that for the aftermarket deck. That's why the splicing and heat shrinking was mentioned.

Yes you are right. I would first connect it to the aftermarket headunit, then splice into the harness for the 3 wires running to the trunk, but it's the same concept.