GG's E39 DSP Delete & PCN Data Collection Thread

[geargrinder]

Note I no longer run a GAS PCN unit in my car. For my current setup, skip to end of post...

Being immersed in the current E39 GAS PCN DSP-delete implementation, I have gathered a bit of data, and thought it would be good to consolidate it in one post/thread instead of scattering across what was really supposed to be the group buy thread.

Disclaimer there could be mistakes here, I have had a few dead ends and errors before but will try to keep this main post edited/updated with 'best' info as it emerges.

PCN Group-buy thread with many details:
http://www.bimmerforums.com/forum/sh...e-(starts-NOW)

E38/9 Speaker Impedances

Work in progress, please submit additional measurements/data

Model	F Tweet	F Mid	F Woof
E39 DSP early	8Ω	8Ω	4Ω
E39 non-DSP	8Ω (same PN as above)	4ohm ? (JimLev measured) 8ohm ? (same PN as others)	4ohm (same as above?)
E39 DSP late	8Ω (same PN as above)	8Ω (same PN as above)	8Ω
E38 DSP	?	8Ω (same PN as above)	?
BSW Stage 1	8Ω	8Ω (some reports 48Ω?)	2.6Ω

E39 Late-DSP Speaker Configuration & Measurements

Various members have had very mixed results testing the speaker polarity of OEM speakers using a StudioSix app & speaker signals.
Seems consistent that the mids are reversed polarity, some seem to find the front tweeters reversed as well, however with my car it seemed like the negative result was bleeding over from the mids, and tweeters themselves did seem to be normal polarity. Below are speaker resistance measurements and polarity results from my car (2002 540iT ex-DSP Touring).

Note BMW Speaker wire convention is Blue for Right and Yellow for Left, stripe indicates speaker, and grounds for each are twisted to the main signal wire and then striped with either brown (front) or grey (rear).

Speaker	Stripe color (return/ground stripe)	Measured DC Resistance / Assumed Nominal Impedance	Wiring Polarity	GAS PCN Measured -6dB Cross-over point at 8Ω
F Tweet	Green (Brown)	7 / 8Ω		9k
F Mid	White (Brown)	7 / 8Ω	Reversed per StudioSix app?	8k & 1.5k
F Woof	Red (Brown)	7 / 8Ω		1.5k
R Mid	Black (Grey)	5 / 8Ω	Reversed?	5k
R Woof	Violet (Grey)	6 / 8Ω		6k
R Sub	Black/White (Grey/Brown)	6 / 8Ω	Normal	N/A

GAS PCN bench sweep test

I bench tested my later-run GAS PCN with a swept sine wave signal, Fluke frequency counter, and oscilloscope to ballpark crossover points, with the following results

Speaker	GAS PCN Measured -6dB Cross-over point at 8Ω
F Tweet	9k HPF
F Mid	8k & 1.5k Bandpass
F Woof	1.5k LPF
R Mid	5k HPF
R Woof	6k LPF
R Sub	N/A

E39 HU Outputs

DSP Headunits will revert to non-DSP outputs after being repowered if no DSP module is connected to the car.
The following outputs should be accurate for all non-DSP configured HU's.

Business CD HU's put out a max 7V RMS level signal (something around a high line level / low for speaker level)
Some have reported good results terminating the output directly with RCA plugs and using as a line-out signal.
Others have had good results with Line-Out converters or high-inputs to amps that have them.

Issues - Phase, Bridge Tied Load, and Fading Problems

Pin-outs per WDS and verified w/ oscilloscope testing are as below.

Output Line	HU Pin	Signal Comment
Front Left +	3	Signal return
Front Left -	7	Driven signal (inverted i.e. negative rail)
Front Right +	2	Signal return
Front Right -	6	Driven signal (negative rail)
Rear Left +	4	Driven signal (normal)
Rear Left -	8	Signal return (normal)
Rear Right +	1	Driven signal (normal)
Rear Right -	5	Signal return (normal)

Basically the Front speakers are driven on the negative side of a 'bridge tied load' system, and the Rears on the positive. If that is goobletygook to you, then just realize the signal is coming on the negative wires of the Fronts and the positive wires of the Rears, while the other sides for each pair are the "ground".

Now normally you might expect if that was the case that you might need to reverse polarity on one pair to 'correct' this. However, real-life testing shows two things.

First, initially I thought that using a LOC (line-out converter) I could connect everything up "normally" (i.e. +|+ -|- on all 4 speakers) and it should come out OK. However, on multiple setups (I have now tried many assortments of config in my car...), due to issues with grounding, this will NOT result in a satisfactory setup. Because of the common ground between fronts and rears when you wire these into a common device like that, when you try to fade/balance the signal F/R & L/R it will cause all kinds of odd things and essentially not fully fade to any one corner. So, for fading to work properly, you need to have one pair (I chose the fronts at this point) to be reversed so you wire +|- -|+ on the fronts and connect the rears 'normally'. With this config the balance controls work perfectly.

Now the first instinct would be that the Front speaker-outs from the amp should be also reversed to compensate for this and re-correct phase, however from again repeated testing, this phase setup seems to result in aligned speaker polarities, so it very well may be the factory handled this in the same way. So my current recommendation is to reverse inputs to whatever LOC is used and not worry about polarity after this.

And since going to a DSP based system I have been able to easily and quickly invert the signal for the fronts back and forth and both 'ear' and quantitative testing show best results with this setup.

Option 1 - full 8-wire setup:

So to restate simply... w/ a full 8 wire setup covering all 4 channels, my recommendation is: Fronts - reverse wiring polarity to LOC, Rears - standard wiring polarity to LOC.

Option 2 - 4-wire setup using OEM available wires:

As above when trying to provide signals via 4-wire-only setups, including the re-use-factory-wiring option, note that the Front driven signals appear on the negative pins.
Therefore in a 4-wire approach, the negative wires must be used from the Front channels, not the positive wires.
A stand-alone LOC might be advisable in the 4-wire approach as well as internal ground references can be tricky in those applications and alternator noise can be severe - BTDT.

Option 2 - 4-wire w/ no F/R fader:

The other simple option to avoid any problems with front/rear polarity would be to use 4 wires (OEM or otherwise) to a LOC or amp that can do 2-to-4 channel generation (or use splitters), then set a permanent fade on the LOC or amp setup.

Factory Touring Sub Stuff:

Few cheap and easy mod tips for the factory Touring sub. That funny little plastic box has a small ~5.75" or so speaker in it with dual 8Ω voice coils. So it can be powered by a stereo output, or run in parallel off a mono amp. A bridge-able amp is perfect for this so you can run L/R signals to it then drive it with the bridged outputs.

In trying to solve FM reception problems I replaced the factory wiring with some 16 gauge twisted pair shielded wire. In the process I also was happily surprised to find this gave a significant output bump. So first easy mod is bigger speaker wire. I can only conclude OEM wiring appears to be sub-optimal perhaps in gauge but also likely in length as it routes around quite a bit before getting back to the subwoffer. This can be easily replaced (super easy to wire across the back of the spare-tire area) with higher gauge wire for better results, and then just bridge the 2 voice coils at the stock plug.

Factory sub-wires are coded as follows :

Color	Wire
Yellow/black	'left' positive
Yellow/grey	'left' negative
Blue/white	'right' positive
Blue/brown	'right' negative

I also modded the sub box itself using an old home speaker trick which entails opening the box up and lining the lower sides with hydraulic cement to stiffen it up and get rid of plastic box resonance. A little fiberglass insulation is tossed in as well - polyfill would be great too but I happen to have insulation handy. There is less in there than it looks in the pix its a really light layer. This really stiffens up the box and firms up the response. It's still a funny little tiny OEM box so you're not going to blow anybody off the sidewalk but if you're keeping the OEM sub, this is a great $3 mod. There's a few tricks to it but its fairly easy in the end.

Factory Touring Roof Speakers:

Measured the factory touring rear speaker pockets in the roof for replacement... surprisingly more room than it appears up there...
Cutout diameter - just a bit over 5", prob about 130-135mm
Depth - about 3", prob 75mm

BMW Business CD Distortion / Gain Testing

Testing the OEM BMW Business CD in my 2002 540iT makes it clear that while the unit will pass test waveforms cleanly at "10", when faced with a broader bandwidth signal, it quickly and badly distorts. This was proven by driving home audio speakers with plenty of power handling capability directly from the head unit with 'dense' and highly compressed signals (full classic rock tracks, large band jazz / bluegrass, modern country pop tracks with high compression...). Around what I can only guess is "7-8" level distortion begins to be clearly audible straight out of the head unit.

As a result, dialing in a gain structure on LOC/amp side based on the HU being on "10" will be extremely mis-leading and result in not only insufficient volume but terrible SQ at high volumes as essentially the OEM deck should never be turned up past "7-8" if possible. My original setup was based on that procedure and any kind of attempt at high volume sounded terrible.

A far higher clean volume is achieved by calibrating the gains w/ HU set around "6-7" and then turning up LOC/amp gains as high as possible while retaining clean sound. In this way the HU is able to provide clean signal and the power amp can provide much more gain and end volume. The HU should then never be turned up too high, but, with the power amp providing so much amplification, it won't be necessary nor endurable to turn it up that high anyway.

One trick is that it is slightly challenging to identify the right spot on the HU volume since it uses a digital encoder (i.e. no hard-stops) and does not provide a numerical volume level on the display, so my "7-8" is purely a ballpark of what it appears to be, however if you turn the volume all the way up, then back it off about 7-10 clicks, this is about the highest volume that can come through clean with a really dense compressed program signal. (Or test it yourself with a speaker hanging directly off the HU outputs and see where you notice distortion start to appear, then back off...)

Noise and interference control

Two issues with my current setup - one is FM interference, the other is background noise.

After extensive testing the FM interference is absolutely coming straight out of the Soundstream Class D sub amp. This is apparently a 'feature' of many of the cheap Class D amps. It appears to throw off a crapload of switching EMI and RF radiation and absolutely destroys FM reception, especially because I have it mounted at the OEM rear amp location, duh, directly below the FM antenna in the rear glass. Problems with this are:

• General RF emissions from the amp getting picked up by the FM antenna
  
• The speakerwire for the amp acting as an antenna to further radiate noise and RF and crush FM
  
• General EMI emissions from the amp getting picked up by the PCN coils due to proximity and probably driving up overall noise

My current config to mitigate this is as follows - it has helped a lot but not cured the situation:
1. Switching to a shielded speaker wire with the shield drain grounded right at the Class D amp.
2. A type 43 ferrite toroid on the speaker wire with ~5 wraps
3. A type 43 ferrite toroid on the ground wire to the amp w/ ~2-3 wraps.

The big problem is my location. My advice - do NOT put a cheap Class D amp 1. in the rear corner back there near the FM antenna, or 2. anywhere near your PCN. If i had this to do over I would at least have the PCN up high on my mount plate and the Class D down 'on the floor' but really I would do my best to pull it out of that location.

I may end up relocating my sub-amp down to the bottom of the tire well near the battery in the end, which sucks because I spent many hours constructing the mount plate with nice T-nuts and spacing properly so that it would fit tidily above the PCN itself, but it's clearly a design flaw. Could also go for another amp but then that's a crapshoot and any other inexpensive Class D is probably going to be the same I am guessing.

Aside from that, during switch over to new amp setup, all the gain structure had to be re-evaluated and re-set given a new LOC and amp was installed. At this point the balance on power amp gains is between background noise and volume.

The warning on gain setup is to balance quiet noise with max volume... turning the system on and setting the HU input to something silent while you adjust main amp settings is important to hear how much background noise you have.

At least in my setup there is some constant low level noise on the HU outs. If the amp gain is turned up too high, this noise becomes audible and objectionable at quiet points. If main amp gains are kept low it is fine but then overall system volume is limited and you have the HU distortion issue mentioned above at high volumes (won't be a problem for those w/ aftermarket HU's).

Tested Setups / Topologies

Below are 3 prior setups I have run with varying success before throwing the stupid PCN in my junk parts pile. For my current setup, skip to end of post...

Eventually I went to a MiniDSP C-DSP unit which was far above the original budget, but results in a very quiet LOC and a tremendous amount of tunability and configurability.

More info about that unit can be found here: https://www.minidsp.com/products/min...-box/c-dsp-6x8

It is basically the same thing as a Soundstream Harmony or Precision Power DSP-88R except latest hardware and a better software for EQ (i.e. parametric w/ REW compatibility vs the graphic EQ in those retail products).


Prior setup w/ an Audiocontrol LCQ-1. This was a fairly adequate solution, and would have probably stayed in place except my LCQ-1 ended up having some kind of internal noise (made buzz even when not hooked up...) I think this was specific to my unit and not endemic to the AC unit but I got sick of flipping around different units and spending increasing amounts and still not have granular EQ capability, and so decided to take a leap up to the C-DSP unit.



This was my previous setup which also worked well although I had more noise and obv could not tame the PCN flaws properly. Alternator noise was a bit of an issue but perhaps this could have been sorted with time or with an outboard LOC vs the internal LOC in the Soundstream amp.



---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Current NON-PCN Setup

After numerous frustrations with the size, connectors, limitations, and sound quality of the PCN, I decided to ditch it entirely.

My current setup consists of this:

• OEM headunit to C-DSP unit as previous
  
• Front speakers setup in bi-amp config, independent amp channels driving each of 4 2-way front speakers (no longer 3-way front setup) using same main 4-channel power amp. At the moment this uses OEM speakers, but the design intent is to replace front speakers and I have the parts and just need to pull door cards and get it done.
  
• Rear touring roof speakers replaced with coaxial units and powered by their own stereo amp. Rear door tweeters completely disconnected (they are a disaster for front soundstage)
  
• OEM sub replaced with Basser sub box (see eBay) and Dayton SW driver

Topology as below.


Mounting configuration consists of two parts.

1. A 'two layer' mount plate in the rear left storage bin

• OEM amp connectors provide interface to vehicle wiring to allow it to be moved in/out easily if needed.
  
• Speaker out wiring from the power amps to the speakers is accomplished with a terminal block which then wires back to the OEM connectors.
  
• The mini-DSP unit is on an outer top panel so that it 'floats' over the 2-channel amp for the rear channels. This also makes it highly accessible to connect to the USB or MicroSD interfaces in order to program or update the unit.
  
• Rear channel amp is mounted below, and is Class AB to reduce interference with FM antennas in the rear

2. A mounting plate under the Touring cargo floor

• Both sub and main Class D amps
• Power & ground distribution block provides large gauge power to both amps from common sources at the main battery fuse junction boxes

These pictures are not current, as wiring has been tidied up considerably since then but this is how it looked in initial testing....
If/when I get time I will update pictures to the current / final slightly tidier setup.

Update Log:
1/7/2015 - Update/rewrite on polarity & balance/fade problems, update interference, updated config diagram
3/13/2015 - Added touring roof speaker measurements
8/1/2016 - Updated for current non-PCN setup

[Michael97528i]

Just so I'm 100% clear on the front channel wiring:

I'll be using all 8 OEM wires from the stock HU to the inputs on my amp (non-DSP car). Even though the front outputs are inverted, I still hook them up positive (HU)-to-positive (Amp), and negative (HU)-to-negative (Amp). Or do I invert the front channels and hook them up positive (HU)-to-negative (Amp) and Negative (HU)-to-positive (Amp). Or does it not matter?


BTW, thanks for consolidating all of this in one place! I'm hoping to be able to install my PCN next week and will provide any additional info on my non-DSP car with the "business cassette" HU.

[geargrinder]

Hey Michael. Yeah. Exactly. If you wire it "Completely Normally" it is totally fine. Positive-positive Negative-negative on all 8 wires.
It's only when somebody tries to pluck one wire from each pair that it gets complicated.

It DOES matter for sure, if you reverse them it will sound ass-y for sure but this is the way to go for sure on that That part I am 100% confident in. HU to AMP, use 8-wires, do it 'normally' and it should be good, as long as your amp doesn't have some weird internal ground sharing scheme.

I am sorry some of my posts on the other thread were erroneous or confused and confusing (sometimes because I forked up or had an error and sometimes because I just mis-wrote it or I didn't describe it well).

That's exactly why I tried to start fresh with this one...

What still needs full confirmation is the tweeter/mid polarity and if you just use those in OEM alignment or not... I would at this point suggest people wire it up "by the numbers" aka by the colors and see how it goes. The StudioSix app does show (as you know from other thread) some weird polarity issues but it's so inconsistent, not clear really what is what. Perhaps having the door cards off somebodies car would help too in case the drivers have polarity marked on them...

[Michael97528i]

Thanks! My amp is a new Soundstream Picasso Nano 5-channel, so hopefully nothing is odd with the internal grounding. Guess I'll see when I get it all wired up...

[geargrinder]

Yeah I probably dont mean "odd" really. I mean if negative returns are internally tied together or to chassis ground. For a modern name brand item thats probably based on copycat reference designs and integrated circuit chips it should be OK... but if that happened you might get no signal out at all. Or some weird noises.

Obv i am using a lower soundstream too so you prob be fine....

[geargrinder]

Just so I'm 100% clear on the front channel wiring:

I'll be using all 8 OEM wires from the stock HU to the inputs on my amp (non-DSP car). Even though the front outputs are inverted, I still hook them up positive (HU)-to-positive (Amp), and negative (HU)-to-negative (Amp). Or do I invert the front channels and hook them up positive (HU)-to-negative (Amp) and Negative (HU)-to-positive (Amp). Or does it not matter?


BTW, thanks for consolidating all of this in one place! I'm hoping to be able to install my PCN next week and will provide any additional info on my non-DSP car with the "business cassette" HU.

Guys - See whole host of updates above in main post.

Including that I am going backwards on this one - notice I am running the rears flipped now. Seems to work better. Tests all properly now using the app... But still working on noise control as noted...

[geargrinder]

First post updated w/ latest setup. More to come later...

[GatoEnFuego]

So...since these GAS PCNs don't appear to be available at the moment (or any longer?) has anyone built custom passive crossovers based on your research above?

[geargrinder]

At this point I would probably suggest anybody looking at E39 audio project...
- walk away from all the GAS PCN hassles
- replace front 3-way setup with high quality aftermarket 2-way system
- possibly delete the rear mid-tweeters, and replace rear big speakers with integrated coax type setup

With a setup like that you would have 2 options:
1 - invest in one quality passive crossover set to match your 2-ways (for ex: Audiofrog speakers & XO's), or better,
2 - run a 6-channel DSP type unit where you can active crossover the fronts individually, and drive the rear coaxes on a channel each

Sure you could make your own crossovers, not difficult, but honestly after all the expense and time if I'd done the above I'd have spent less money, WAY less time, and ended up way ahead of the game with a way better system.

In fact I may do exactly as above. Then I'll burn my GAS PCN (burn the GAS with gas!) and post the video to YouTube. I heard some weirdness last night cranking at high volumes and I think the increased power may be blowing out my rear mid-tweets already, and honestly they are so close to the drivers ear (if you aren't 4 feet tall and have the seat pushed way forward at least) they really screw up the soundstaging anyway. If you are just looking for some fill in the rear for the occasional rear passenger and to fill and pull the soundstage back just a bit, the main rear speaker locations should be fine.

[GatoEnFuego]

At this point I would probably suggest anybody looking at E39 audio project...
- walk away from all the GAS PCN hassles
- replace front 3-way setup with high quality aftermarket 2-way system
- possibly delete the rear mid-tweeters, and replace rear big speakers with integrated coax type setup

With a setup like that you would have 2 options:
1 - invest in one quality passive crossover set to match your 2-ways (for ex: Audiofrog speakers & XO's), or better,
2 - run a 6-channel DSP type unit where you can active crossover the fronts individually, and drive the rear coaxes on a channel each

Sure you could make your own crossovers, not difficult, but honestly after all the expense and time if I'd done the above I'd have spent less money, WAY less time, and ended up way ahead of the game with a way better system.

In fact I may do exactly as above. Then I'll burn my GAS PCN (burn the GAS with gas!) and post the video to YouTube. I heard some weirdness last night cranking at high volumes and I think the increased power may be blowing out my rear mid-tweets already, and honestly they are so close to the drivers ear (if you aren't 4 feet tall and have the seat pushed way forward at least) they really screw up the soundstaging anyway. If you are just looking for some fill in the rear for the occasional rear passenger and to fill and pull the soundstage back just a bit, the main rear speaker locations should be fine.

Thanks for the quick response. I have a late model E39 with DSP MK4 Nav and widescreen. I plan to pull the entire set up, sell it and go with a Dynavin headunit but the speakers are still a bit in flux. I originally planned to replace all of the speakers and use a decent aftermarket amp and not worry about it. If you replace your front speakers, would you put the aftermarket tweeter in the mid spot (right above the door handle) or in the high spot up by the mirror? I've been looking at these a decent set of components for the front, I know they aren't super high end but about what my budget allows when you factor in the headunit, amps and sub. http://www.polkaudio.com/db5251/d/1097C2670

[geargrinder]

Great question Catonfire. As I think about ditching the PCN and speakers, my thoughts are that the tweeter spot is definitely more ideal but you can search teh innerwebz for guys fitting tweeters in there and the challenges to getting a good fit.
The mid-location could be good enough and is clearly far easier to deal with physically vs speaker options. But if you can make the top spot work its def preferred I think.

IME there's a lot of really good quality in modern "mid-fi" gear if you shop carefully. Dont know anything about Polks these days - had some in a Saab years and years ago and they were good solid "mid-fi" but that has no bearing on what they are making now...

BTW there's some guys selling wooden speaker frames that replace the plastic boxes inside the door for aftermarket speakers... not sure if you've seen that...

[GatoEnFuego]

Great question Catonfire. As I think about ditching the PCN and speakers, my thoughts are that the tweeter spot is definitely more ideal but you can search teh innerwebz for guys fitting tweeters in there and the challenges to getting a good fit.
The mid-location could be good enough and is clearly far easier to deal with physically vs speaker options. But if you can make the top spot work its def preferred I think.

IME there's a lot of really good quality in modern "mid-fi" gear if you shop carefully. Dont know anything about Polks these days - had some in a Saab years and years ago and they were good solid "mid-fi" but that has no bearing on what they are making now...

BTW there's some guys selling wooden speaker frames that replace the plastic boxes inside the door for aftermarket speakers... not sure if you've seen that...

Appreciate that, I'll probably just go with the mid spot and call it done. It's been more than 10 years since I've messed around with car audio, in my younger years I had a few "pumping systems" but just recently decided to dip my toes back in.

[DennisCooper]

Appreciate that, I'll probably just go with the mid spot and call it done. It's been more than 10 years since I've messed around with car audio, in my younger years I had a few "pumping systems" but just recently decided to dip my toes back in.

Hi,

The oem tweeter location in the front doors is the ideal location for most tweeters you'd find in quality brand 2/3 way speaker systems. There are some tweeters you can purchase separately which 'sound' better when used in an 'off axis' orientation and some of those could/would sound better in the air vent location where the oem midrange speaker would be. That'd take quite a bit of placement testing to ensure you do get the benefits for good imaging and staging and is usually done by those who've put in a fantastic sound quality orientated install etc. For the Polks you've referenced, and perhaps speaker kits at the $150-250 level, then you'll likely find the tweeter will fit into the oem tweeter location easily. In my E39, I've 'angled' the passenger side tweeter to play more towards the driver's side to improve imaging and staging and I'm very happy indeed! Another owner with his M5 put his tweeters from a higher end speaker set in the 'mid range' location and it just 'didn't sound right' and I told him so! a few days later, much improvement in the sound once he'd put the tweeters in the oem tweeter location

Cheers, Dennis!

[geargrinder]

Quick update note - as several know already, a few weeks ago I had a failure w/ the C-DSP unit which suddenly sent a high volume static blast through my system, causing the front tweeters to blow out, the OEM sub to blow out, and my main amp to burn up.

Very odd and minidsp is being extremely supportive on the situation but at this point this will initiate a whole new setup, likely something like this:

• PCN will be tossed in the nearest ditch (well OK probably not really, but will be FS, probably with an E39 mounting plate)
• C-DSP retained but some 'safety' configuration changes to A. Gain structure (main amp gains down and C-DSP gain up...) and B. Amp on-board crossover filters (none were turned on as C-DSP did all processing but turning on hardware crossovers on the amps set well outside the software crossover would give some safety margin)
• New speakers all around - 2-way setup in front, new coaxials in rear roof locations and rear mid-tweets disconnected, and a new homebuild sub cab made to fit the back cubby
• Either use crossovers that are provided with new speaker setup, or, will add amplification and bi-amp the fronts, resulting in no need for outboard passive crossovers at all.

Thread will be updated accordingly when I get to next phase...

[GatoEnFuego]

Hi,

The oem tweeter location in the front doors is the ideal location for most tweeters you'd find in quality brand 2/3 way speaker systems. There are some tweeters you can purchase separately which 'sound' better when used in an 'off axis' orientation and some of those could/would sound better in the air vent location where the oem midrange speaker would be. That'd take quite a bit of placement testing to ensure you do get the benefits for good imaging and staging and is usually done by those who've put in a fantastic sound quality orientated install etc. For the Polks you've referenced, and perhaps speaker kits at the $150-250 level, then you'll likely find the tweeter will fit into the oem tweeter location easily. In my E39, I've 'angled' the passenger side tweeter to play more towards the driver's side to improve imaging and staging and I'm very happy indeed! Another owner with his M5 put his tweeters from a higher end speaker set in the 'mid range' location and it just 'didn't sound right' and I told him so! a few days later, much improvement in the sound once he'd put the tweeters in the oem tweeter location

Cheers, Dennis!

Sorry for late response, I really appreciate the suggestion and will put in additional effort to get the tweeters in the stock tweeter location!

[DavidX5]

Interesting read...

I've got a Dynavin N6 on the way (will be here this week), and am planning the install on my 2005 E53. I've got factory NAV and DSP and the initial plan was to install the Dynavin along with the GAS PCN and a 5 channel amp. Now, I'm considering using a DSP instead of using the GAS PCN.

My current thinking is to use the Soundstream Harmony or the miniDSP C-DSP along with a couple of Soundstream 4 channel amps (6 channels for the fronts and 2 bridged for the sub). The only downside I can see is not being able to use the rears with this setup, but I like my image up front, and it would be cost prohibitive to get a processor with enough channels to handle all the speakers anyway.

Any thoughts on my plan?

David

[geargrinder]

Yes thoughts. FWIW I can only speak to my E39 experience although I'm going to assume E53 speaker setup and perhaps parts are roughly equivalent... That is more or less exactly what I am going towards. I will toss the PCN space-consuming mediocre-sounding mess out, and replace with a near-full active cross-over setup.

Confirming my post above...

Basically my next setup will be C-DSP with:
4 channels into 4-channel amp for Fronts active crossover
2 channels into 2-channel amp for Rears (onboard crossover coaxial speakers)
2 channels (only one needed really...) into bridged amp for Sub

So nearly what you are proposing except dropping the 3-way up front. I am going to go to a 2-way with a decent quality silk dome tweeter in the top position, and a new beefy woofer in the bottom (if you wanted to go real budget the factory woofer is surprisingly good so that could stay and you could just do a real quality tweeter in the top). I don't think the 3-way brings any real advantage - so many home audiophile designs now have gone away from multiple drivers (unless you're talking about line arrays which is a different story...) for all kinds of reasons and the 3-way really doesn't bring any advantage and in fact brings some negatives. Comb filtering, time alignment, all that kind of stuff.

In the rear of my Touring I have disconnected the rear tweeters already because they only serve for rear-passenger benefit and then to screw up the imaging for front passengers (because they end up really close to your ears) and then imminently replacing the roof-mounted mid-bass woofers with 2-way coaxials instead. These are purely for a little rear fill because I find car audio that is only in the front doors to be a bit lacking. A more ideal setup is to change speaker mounts in rear (can see DennisCooper's setup where he built mounts for speakers in the D pillars pointing forward) but rear speakers aren't that important to me.

Instead of building my own sub-woofer cabinet I have sourced a custom E39 one from "Basser" in Poland on recommendation of another lister and it is a shockingly decent box - far better than I had expected for the price. See his auctions on eBay for easy ordering (he seems to have an E53 as well)
http://sklep.basser.pl/en/fit-box-en...enclosure.html

From experience so far with how good the C-DSP makes the PCN/stock speakers sound, I expect this to sound outstanding and expect it to be far better than the PCN solution. No to mention ditching that huge pile of PCN parts that takes up space in the rear cubby. The only real downside of my system will be keeping the factory HU, but I could always upgrade that when I like and keep everything else in place.

Re: Soundstream Harmony vs C-DSP - FWIW the Harmony is an old version of the MiniDSP and only has graphic EQ not parametric. Aside from that downside, it's obviously an "OEM'd" solution so you are dependent on Soundstream for any firmware/software updates and I would bet my pile of used PCN parts that they are done releasing any kind of software upgrades for it ever. In contrast, MiniDSP supports customers directly, continuously updates both the PC config software and the unit firmware, and has excellent response to issues in my experience. While I indeed had this funny glitch, they have been amazing about immediately sending out a brand new unit from Hong Kong completely at their cost, sending me a couple iterations of beta firmware to test and provide log files back, and indeed believe they have found the issue that caused my rare glitch situation. I fully recommend them as a company even though I was an unlucky guy to suffer a rare software bug (only 1 or 2 other people have reported this bug on the MiniDSP forums and neither of them had a bad problem from it - prob had more robust speakers and a better gain-structure setup so they couldn't blow out anything...)

In regard to the PCN vs Aftermarket-DSP argument I see the pros as follows...
+ highly configurable and gives you infinite fine crossover / EQ / time alignment capabilities
+ ability to have multiple configs switched by the remote
+ you need some kind of LOC anyway for PCN and the DSP is high quality and silent (i.e. alt noise etc.)
+ PCN plus some kind of LOC takes up stupid amount of space
+ I believe PCN picks up noise on those huge coils sometimes.
+ and potentially can cause radio interference or at least hurts reception
+ PCN has some less than ideal design choices (not zobel'd for instance which might explain the problems)
+ wiring amps direct to stock speaker wires is immensely easier than wiring amps->PCN->harness all in that back cubby
+ in my setup at least the physical locations will be better (better to have DSP in the rear cubby and class D amps under-floor)

Negatives would be...
- need to wire up the DSP w/ power and turn on etc.
- need more amp channels and amp mounting to be worked out (but you have the PCN space to use now...)
- need more Coax wires running around the car as everything wont fit in one place
- another remote control wire to run if you want to use it, and perhaps a USB cable to run if you want regular access to the unit

[DavidX5]

Thanks for the recommendation. Glad to know that they identified the issue that blew up your system. I'm convinced that the miniDSP is the way to go. I like having the flexibility of the DSP. I also added the cost up, and it's the same or less to go the DSP route as opposed to the GAS PCN setup, even with the added amplifier.

I'm going to use Soundstream Picasso Nano series amps in my system because of their small size. There will room for two 4 channel amps and the DSP in the left rear compartment where the factory NAV, CD changer, amp and bluetooth module currently reside. I'll drive the factory 3-way setup in front and a sub in the rear. I'll just use the front and subwoofer outputs on the Dynavin. That way, I can adjust the subwoofer level from the head unit. Because I'm using the Dynavin, I won't have to use LOC's, just RCA cables from the head unit to the DSP.

[geargrinder]

Warning - the Nano will throw up a crapload of FM interference. BTDT. It will blow your distance reception away unless you take precautions. Keep them way way away from the FM antenna if you can (I failed to do this). You can also throw a toroid choke in the powerlines which I finally have proven makes a real difference, but when I reconfig my setup the amps will go under the load floor to get as far away from FM antennas as possible (the Nano will will get the choke there too...).

Does the X have space under the load floor in front of the spare too? In between where the shocks are more or less? that's a nice big empty rectangular spot there on the touring.

FYI the Nano should come with a remote for use w/ SW. I have mine in the center console and adjust SW that way. If you used that you could just run all 4 regular channels to the C-DSP and let it derive the SW signal for the Sub amp, then still have F/R speaker control on the HU and SW control in the cockpit. You could also go passive crossover to the rear speakers and bypass the C-DSP for that signal.

Another old trick in case like yours is to use the onboard amp in the HU to directly power the rear speakers. Use outboard amps for the big stuff (fronts and sub) but push the rears from the HU built-in power. You'd need a little passive crossover for the rear tweeters but you could buy some generic thing to use for that...

[DavidX5]

Thanks for the heads up on the FM interference. Unfortunately, the X5 has NO space under the load floor. I'm going to mount the amps in where the factory amp is, which is on the side, but down mostly below the load floor level, so hopefully that will help. Interesting idea on using the head unit amp for the rears. I'll keep that in mind if I end up missing the rear channels at all. I've already bought a cheap used DSP amp off of eBay to cannibalize the connectors from. Should make it easier to hook up the rears if I decide to.

[geargrinder]

Yep that will work perfectly. Exactly what I did. Disassembling the OEM DSP is a lot more hassle than you might expect by the way. The big connector is a giant PITA. I might do it differently next time... might cut the PCB up and leave some of that attached to the "pins".

For the amp location - just be sure your D-class amps are as low and far away as possible, and look into getting a large ferrite torroid big enough to get like 2 wraps on the power & ground wires side-by-side. I can give you example of what I got (depends on how big your power wires will be).

[DavidX5]

Yeah, I've already taken the DSP amp apart to have a look and it's not going to be too easy. I've done a lot of soldering in my day (I was certified in mil-spec soldering when I was in my early twenties), but that many pins is not fun to de-solder! The upside is that it will be MUCH easier to do on the bench as opposed to standing on my head, leaning over the tailgate of the X5 and splicing 20+ wires! I'm going to use some multi-conductor cable and lots of heat shrink.

I'd be interested in what ferrite torroid you use. I'll use 8 AWG from the fuse to the battery. One nice thing is that the battery is right there under the spare tire, so really short run.

[geargrinder]

I use a desolder station (i.e. melt & suck) which crushes disassembly. The little connectors are easy w/ that gear (I'd rather chop my junk off and grill it on the barbeque than have to spend an afternoon using solder wick...) but even with that the big connector things are a PITA. Your multi-conductor will be sweet, I have some scrap stuff around but didn't have anything right for this build aside from using Cat 6e for my HU to DSP run... works well it seems...

Toroid-wise - This is the big ass one I have on there now but it's not ideally config'd at moment. In reconfig I'll get a good few tight wraps of the ground and power conductors around it. Right now I have only about a turn and a half but that's because I am jury-rigged and just initial testing it.
http://www.mouser.com/Search/Product...623-5943003801

I ordered a few others too and formerly used a smaller one on a smaller wire. You can look at other sizes depending on what power supply wires you plan to use - mouser has a ton listed (just watch their catalog as they list so much stuff and much of it is special order non-stocked only....)

You need to get it as close to the unit as possible as its the output wires turning into antennas to broadcast interference that cause the problem. You can also use different ferrite materials like #77 or whatever and using multiple with different characteristics is ideal as it eliminates chance of 'ringing' oscillation occuring but I'm not sure its that much of a danger or worth the space & hassle (fat amp power cables get huge fast when you have to wrap them around a giant ferrite toroid.

On top of this on my noisy amp (Picasso Nano) which is my sub amp, I use a big twisted pair for speaker wire with a shield on it and ground the shield to be sure no ripply RF comes out of the speaker wire either (reported to happen w/ these amps also...)

HTH.

[DavidX5]

I use an Edsyn Soldapult that I've had since I was in my early teens (good gosh, that's about 40 years!). It works pretty well. All those small speaker connector pins are gonna be fun! I'm considering putting the connectors in a small ABS plastic project box just so I can protect the pins and put a strain relief on the cables.

That toroid looks good. Thanks for the linky. I'd be very interested to know how well it works when all is said and done.

Can't wait to get started on this, but I have to get the passenger side door lock fixed first so I can get into the car on that side!

[geargrinder]

I use an older cheaper (non digital) version of this:

http://www.sra-solder.com/aoyue-701a...dering-station

If you do any electronics repair at all of through-hole stuff it's fantastic. Makes desolder jobs like this SO easy...

As far as I can tell its Chinese knock-off (or maybe even licensed old-models as they are discontinued?) of Hakko stuff so it is parts compatible w/ older Hakko stuff and I order Hakko parts for it.