E39 Speaker Upgrade Opinion?

[RedRover917]

So after a ton of research, below is how I’ve decided to upgrade the audio system, and was hoping to get some opinions/advice.

Head unit: Scored a Dynavin N6!

Front MidBass 5.25”: Replace with 5.25” Polk Audio DB522. Peak RMS is 100 watts and the top mounting depth is 1 3/4”

Rear deck: Plan is to remove the Nokia box and install two 10” free air JL Audio subwoofers. Peak RMS 175 watts each.

Amp: Plan is to remove stock DSP amp and replace with an MB Quart ZA2-1500.5 Class-Q1 amp which at 4 ohms will crank out 4 x 60 watts, and 1 x 350 watts.


Is there a concession on what is the best option to upgrade from OEM DSP system in a e39?

[Firstbmw528]

In my opinion looking at your idea you may find you’re missing some punch since you are only running 5 1/4 as well as it sounds like infinite baffle subs.

I would double check that there aren’t better reviewed subs for infinite baffle because I know some are built for it

[geargrinder]

By "free air" he means infinite baffle subs, so, I'd imagine those JL's are not shabby. I wonder however if you might not use one of those new slim-profile underseat type subs but bolt it up under the parcel shelf instead. People seem to love those, although they ain't cheap... prob give more bang than the free-air...

Rover - the trick is that the scads of OEM speakers (i.e. 5x2 = 10 plus sub) are all individually amped by the DSP with no external crossovers.

So if you're replacing the DSP amp (which indeed nets big results in sound quality) you need to decide how to do deal with all those individual speakers....

The basic options are one or both of the following:
1. Add crossovers - to split up the 4 corner channels from your amp to the speakers (and then work out re-wiring to match)
2. Implement an active crossover, with individual amp channels for each driver (and then you can still use factory wiring)

In my touring (slightly different speaker config than sedan but close enough) I went with #1 for the rear speakers - replaced the rear tweet+mid-woof with some coaxials with onboard crossovers.

Then in the front I went #2 (heh) - I use a "cDSP" unit from MiniDSP to drive all the channels and do active EQ and crossover, then after that I have 4 dedicated amp channels for the front speakers. I have threads on it.

My thoughts re: factory speakers.

• Front mid-woofs are actually kind of excellent. I replaced them myself but honestly they are shockingly good. Dont let appearances of magnet size or whatever fool you - they go crazy low and sound really pretty decent. This was probably the least bang for the buck in my upgrade and if I had it to do over again I might save the labor and money. Not saying you can't improve them for sure, just that they would be low on my priority / bang-for-buck list.
• Front 3-way layout with the 'mid-tweet' (more like a conventional tweeter really) and then the micro super-tweeter, is mostly a marketing thing and a waste of time to re-implement IMO. You CAN upgrade the sound of the tweeters up front for sure (that is worth the time / effort). Personally I used the big tweeter spot and mounted a neodymium dome tweeter there, and then ditched the super-tweets (which I'd blown out already with an accidental static blast) so the fronts are 2-way. 3-way gets you nothing much except bragging rights and looking cool and in fact has soundstage downsides from a time-alignment perspective. And by going 2-way in front you simplify the channel hassles a little.
• The rear mid-tweets in the doors eff up the soundstage for the front listeners because they are almost in your ears unless you're super short and the seat is way forward. I also deleted those and use a coax speaker in the rear touring locations. This was a big improvement. You can do same thing for the sedan parcel shelf speakers. By using a coax with an onboard crossover there you eliminate at least one channel of hassle.

DSP replacement is a real hassle unfortunately but is worth effort and your system if you get anything like that will sound great (better than mine since I've stubbornly stuck w the OEM headunit... an N6 would sound a zillion times better I'm sure...)

HTH.

[RedRover917]

So after a ton of research, below is how I’ve decided to upgrade the audio system, and was hoping to get some opinions/advice.

Head unit: Scored a Dynavin N6!

Front MidBass 5.25”: Replace with 5.25” Polk Audio DB522. Peak RMS is 100 watts and the top mounting depth is 1 3/4”

Rear deck: Plan is to remove the Nokia box and install two 10” free air JL Audio subwoofers. Peak RMS 175 watts each.

Amp: Plan is to remove stock DSP amp and replace with an MB Quart ZA2-1500.5 Class-Q1 amp which at 4 ohms will crank out 4 x 60 watts, and 1 x 350 watts.



Is there a concession on what is the best option to upgrade from OEM DSP system in a e39?

[Dave Sal]

• The rear mid-tweets in the doors eff up the soundstage for the front listeners because they are almost in your ears unless you're super short and the seat is way forward. I also deleted those and use a coax speaker in the rear touring locations. This was a big improvement. You can do same thing for the sedan parcel shelf speakers. By using a coax with an onboard crossover there you eliminate at least one channel of hassle.

HTH.

Agree. I had my aftermarket system done professionally by an MECP certified installer. He recommended deleting the speakers in the rear doors as they would be bad for the sound stage. He was right.

Also, regarding the subwoofer, I've read many comments over the years about cutting holes in the rear deck or the rear seat back for a trunk mounted sub. I have an MTX BGE12 subwoofer in the trunk powered by an Alpine M100 mono amp putting out 100wpc. I have the fold down rear seat option and if I have one of the seats folded down, the bass becomes overpowering. With the seats upright, it sounds perfect.

trunk interior.JPG

[geargrinder]

On advice of a couple car-stereo dudes, I ran a sub volume-remote knob up to the cabin from the sub amp and its GREAT.

If you're on a 'modern' bass-boosted FM station for instance you prob want to dial it back... if you're listenin to 'old' music mastered with low bass content, you want to dial it up, etc. etc. Also in case like you describe Dave, with the Touring there's all kinds of 'configurations' back there (seats up + cargo cover, seats up no cargo cover, half seat down + cover, etc. etc. tons of crap in cargo area, empty cargo area) and so being able to tune that up on the fly is key...

A few months back I finally did a nice little project and cut up an old center console cargo box so the remote for the Sub and the remote for the MiniDSP unit are both installed in and hidden behind the sliding roller cover stash box. Super clean but also right by your hand when you want to check it out. I never posted a pic I'll try and do that later today...

[Pelican Parts]

That is going to be a great sounding setup - all really quality components!

[Solo12]

RedRover917
Firstof all what are your goals for this upgrade? Bass, clarity, budget upgrade and ditch the DSP, some combo of those, or something else? I have done a good amount of research to upgrade the soundsystem in my e39. While I am not an audio expert my thoughts/questions are as follows.

Fronts

• Are you going with coaxial speakers up front instead of components for budget reasons, to simplifying wiring/rewiring, or another reason? I was under the impression that going with components upfront is preferable.
• Fyi not sure if it is a worthwhile upgrade or not, but there are mdf adpaters that will let you run 6.5” speakers up front. See link

Rears

• You don’t mention rear speakers so are you sticking with the stock system there?
• If not, many people feel going with coaxials in the rear like geargrinder said is the best option for the messed up soundstage and wiring reasons he mentioned. Added bonus they are cheaper.

Amp

• I think you may want a little more than 60w to power those Polks, but I could be wrong. And obviously you can start to spend a lot of money on a nice amp.

Subs

• Your choice should be nice an improvement over the dsp nokia box.
• My knowledge of correctly wiring subs is limited though so whether you get can enough power to them/wire them correctly with that amp I can’t say.
• Fyi some people have cut out more metal on the underside of the rear deck on the theory it allows more sound/bass into the cabin(see attached pic). If you diy I would do that. If you are having something else do the work, maybe skip it unless you really really trust them not to mess up your car.
• Overall there are a bunch of ways to improve the bass in the e39 each has pros and cons. A big benefit to the free air rear deck subs is they don’t really take up any trunk space, especially if you get low profile ones.

Geargrinder
Are you saying a good budget setup would be

• New front tweeters
• Leave the OEM mid-bass there (obviously ditch the mid-tweet and go to a 2-way setup)
• New coaxial rears
• New sub/subs
• New aftermarket amp

If you go that route is there a concern that the speakers would not be matched? Or do you think the whole matching thing is exaggerated especially since the rears are really used more for fill? Or maybe using good crossovers eliminates the issue? I am sure how much of an audiophile you are would play a part too.

[RedRover917]

Yes exactly, the “free air” subwoofers have infinite baffles and meant to be used without a box. The idea is to retain as much trunk space as possible, and pretty much mimic what the OEM optional M-Audio sound system looks like in the e39 M5 (two 10” subs instead of the Nokia box).

Adding the active crossover sounds like a great idea, but when you say splitting the “four corners”, do you mean the midbass speakers in the front doors and the two speakers in the rear deck that will be replaced by the subwoofers? Or are there two speakers in the rear doors?? If so, what size are they??

[RedRover917]

The Dynavin N6 has six outputs (two front L/R, two rear L/R and two subwoofers L/R). So if I were to wire the front doors to the front outputs, rear deck 10” subs to the subwoofer outputs, that would leave me with two unused outputs out of the Dynavin. Unless I can locate the two rear speakers in between the front doors and rear deck?? (On rear doors?)

The amp has a dedicated 5th channel that outputs 350 watts, which I would split up across the two subwoofers (which conveniently max out at peak rms 175 watts each).

Could I double up on the 60 watt outputs to each of the front speakers, pumping them with 120 watts each (peak rms on them is 100 watts) or would that blow out?

[RedRover917]

The goal for this upgrade is to ditch DSP on somewhat of a budget, while retaining trunk space (and ability to fold down seats), while still packing somewhat of a punch.

Wow those upgraded rings to fit 6.5” speakers look pretty sweet... but, will there be enough cubic space in the boxes to make up for it?

I’ve considered these bigger door boxes that maximize the space in the doors, but seemed out of my budget right now at $150 x 2

http://store.12velectronics.com/prod...er-Mounts.html

What size are the “rear speakers”?? You aren’t referring to the 5.25” speakers in the Nokia box on the rear deck lid, are you??

[geargrinder]

• Are you going with coaxial speakers up front instead of components for budget reasons, to simplifying wiring/rewiring, or another reason? I was under the impression that going with components upfront is preferable.
• Fyi not sure if it is a worthwhile upgrade or not, but there are mdf adpaters that will let you run 6.5” speakers up front. See link

Rears

I didn't realize those were coax for the fronts. The treble will suck for that if that's the case... It'll be all aimed down at your knee. Unless you keep one of the factory tweeters as well in which case you have frequency response issues if both a coax tweeter and a stand alone tweeter are handling duties. No reason to use Coax in the front basically.

Geargrinder
Are you saying a good budget setup would be

• New front tweeters
• Leave the OEM mid-bass there (obviously ditch the mid-tweet and go to a 2-way setup)
• New coaxial rears
• New sub/subs
• New aftermarket amp

Yes - at least 'ditch one of the tweets'. Some guys are really convinced the top 'supertweet' corner location is so important that you should jam a driver in there, I think the mid-tweet location is good enough for my purposes and it allows a somewhat larger more reasonably sized tweeter, but if you want to try to squeeze a microtweet in the corner as part of the 2-way thats' fine by me too and a lotta guys do exactly that.

As mentioned before, how you crossover those front channels are the only question. If you go simple passive crossover then you are back in the realm of an easy 4-channel + sub layout and life is easy. Or if you have an active crossover... then you're doing 6-channel + sub...

I LOVE my cDSP, (its like having a standalone ECU for your car audio...) but passive crossovers can sound great too... JimLev has some older Boston speakers in his car with the matching crosssovers they came with and a big JL amp and it sounds pretty great. Much less drama than my installation project required.

If you go that route is there a concern that the speakers would not be matched? Or do you think the whole matching thing is exaggerated especially since the rears are really used more for fill? Or maybe using good crossovers eliminates the issue? I am sure how much of an audiophile you are would play a part too.

1. Yep in general I think matching is a bit over-rated. If you want to be super audiophile obviously then youd be compelled by your own tight anal sphincter OCD spasms to make sure all parts match... but really 'match' is only important in as much as the frequency response vs crossovers and each other is pre-programmed... With an active crossover type system like I have you can EQ each and every driver (OK not for the rear coax tweeters vs woof but those are hardly important...) Good drivers are good drivers for the most part. If you have super 'colored' speakers then indeed maybe a brand mismatch is going to be obvious and sound weird but again if you can EQ the inconsistencies out then its fine. HOWEVER.... 'matching' certainly is the easy shorthand way of getting similar quality assurance in each driver... Like if you buy all JL drivers then you know you're getting a decent product... but inherently mixing speakers is not the horrible nightmare some make it out to be...

2. And especially yes keeping in mind you properly positioned this as "budget" setup... If you want to worry about every little audiophiliac nit pick then you'll be aghast at the idea of using the factory speaker wiring for instance... and then you're not in budget territory for either labor or cash...

There's a lotta marketing and hooey and snakeoil in the audio biz, I tend to be a pragmaticist with a desire to have great sounding system at a reasonable cost, without going too crazy in either cash or labor, and I have a bunch of systems that fulfill that requirement successfully.

when you say splitting the “four corners”, do you mean the midbass speakers in the front doors and the two speakers in the rear deck that will be replaced by the subwoofers?

When I say 4 corners I mean the real 4 'master source channels' from the head unit aka FL/FR/RL/RR.

What size are the “rear speakers”?? You aren’t referring to the 5.25” speakers in the Nokia box on the rear deck lid, are you??

I think you're confused.

There are rear "parcel shelf" speakers that pair with the door tweeters to make up the rear corners.

There is also the rear sub that is UNDER the parcel shelf.

So indeed you have 4 corners as normal.

I’ve considered these bigger door boxes that maximize the space in the doors, but seemed out of my budget right now at $150 x 2

http://store.12velectronics.com/prod...er-Mounts.html

Those are nice looking items and make it easy to retrofit bigger mid-woofs in front. I considered them for a while... Frankly I dont think the plastic boxes are as big of an issue as some guys think... there's a tendency for guys to FREAK OUT if something is made out of PLAASTICCC!!!! !NNNOOOOO!!!!!!!.

Bottom line, the plastic box contains the speaker and gives it acoustic suspension so it doesn't have to be 'infinite baffle', and, because of the heavy door insulation and general mounting/construction, is not particularly resonant (aka not a big problem) so I am not rabid about having to to yank it out. Again those items are kinda nice for an easy size-upgrade for speakers tho, and although you could also homebrew them with a jigsaw and/or router but for $150 that saves a weekend of sawdust and trial and error..

[RedRover917]

Yes, I think I was confused indeed!

I didn’t realize there were 5.25” speakers back there, along with 5.25” woofers in the Nokia box. So now the 5 channel amp set up you mentioned makes sense to what you said... The four channels from the amp to all for corners (5.25” each), then the 5th channel split into the two 10” subwoofers.

Good call on the component set up up front. I found a set of Polk Audio DB5252 (comes with two 5.25” component speakers, two 3/4” tweeters and two crossovers).

Questions:

• Will 3/4” tweeters be ok in front or do I need 1” tweeters?

• Up front, since the amp is four channel, I need an in-line crossover in between the amp and the speakers/tweeters, correct?

• Did I read correctly that it is ok to ditch the rear tweeters? If so, better coaxial speakers back there or component without tweeters?

[JimLev]

3/4" tweeters should be fine.
Use the crossover that comes with the speakers.

[Solo12]

Wow those upgraded rings to fit 6.5” speakers look pretty sweet... but, will there be enough cubic space in the boxes to make up for it?
I’ve considered these bigger door boxes that maximize the space in the doors, but seemed out of my budget right now at $150 x 2
http://store.12velectronics.com/prod...er-Mounts.html

Geargrinder pretty much answered this. I would lean towards what he said. Unless you are an audiophine I would say skip those $150 ones and get the cheaper ones or just stick with 5.25" speakers. I am not sure if/how much of an improvement there would be to going to bigger speakers up front. I just wanted to throw it out there in case you had not heard of the option, but it sounds like you had.

If you were asking if those cheaper rings will actually give enough physical clearance to mount a 6.5" speaker, I think they will, but I am not sure. I don't remember what thread I saw those in, but I believe board members have used them and they worked.

I found a set of Polk Audio DB5252 (comes with two 5.25” component speakers, two 3/4” tweeters and two crossovers).

Questions:
• Up front, since the amp is four channel, I need an in-line crossover in between the amp and the speakers/tweeters, correct?
• Did I read correctly that it is ok to ditch the rear tweeters? If so, better coaxial speakers back there or component without tweeters?

fyi there is also the older discontinued version the db5251 (db521 is the coax version). I mention this because when I was looking at speakers in the spring I saw some of those on sale. Not sure if any of the old ones are still available. From what I understand you may need to widen the front opening by 1/10 of an inch in the front for the db5251. You may also need to widen the rear opening up a tiny bit for the db522 (not sure about the db521).

I think the included crossover takes care of that, but geargrinder, JimLev, or someone else can give you better info on that. fyi JimLev had some really good posts about how he did his system, putting the crossovers in the trunk (where the OEM amp is), creating a custom harness, and not cutting up any of the factory wiring. Prob more time and work than most people want to do, but I wanna do something similar when I do my setup.

Yes many feel it is okay to ditch the rear component setup and go with coax back there. The theory is the rears are used mostly for fill sound, so go to coax speakers to save yourself some money and wiring. Also many e39 people feel the placement of the rear tweeters throws off the soundstage as the speakers are too close to the driver's head (as geargrinder articulated). I suppose if you are audiophile you could use a component setup, but if that is the case you might also relocate the tweeter placement.

As far as the sub location goes. When you remove your nokia box you should see the mounting location. It should look very similar to the pics I posted earlier (left is stock). Fyi this thread here has some good tips on mounting subs using a diy mdf ring.

Geargrinder thanks for the useful info. I am still saving up and trying to figure out what components to use. I definitely want to keep my oem MID. Keeping the stock mid-bass and just upgrading the tweeter is an interesting idea versus going with a new component setup up front esp since I am not audiophile picky about sound.

[RedRover917]

Thank you everyone for chiming in, GearGrinder, JimLev, Dave Sal and Solo12... very helpful.

So even when keeping the stock 5.25” sizes, I may have to widen the cutouts in the doors and rear parcel shelf?

Regarding mounting the subs, I heard that in the 01-03 e39 the mounting screw holes are already pre-drilled to attach the optional M-Audio 10” subwoofers, I guess I’ll find out. I was also going to take a dremel and widen those holes in the deck to allow more bass flowing into the cabin as mentioned above.


Question:

Since I’m trying to stay on a budget, could I get away without installing an active crossover by just running the RCAs from the head unit to the corresponding channels in the amp, then to all four corners from the amp (inline crossover for the front component 5.25”, and delete rear tweeters with a 5.25” coaxial rear). Then also run the dedicated RCA subwoofer outputs from the head unit to the 5th channel in the amp, which would then feed into the two 10” subs.

Does that sound like a solid plan?

Thanks again for all the insightful advice.

[JimLev]

Not sure if anyone mentioned this, make sure the depth of the new speakers isn't going to be an issue.
I didn't use an active crossover, the BMW HU fed my JL Audio XD400/4 amp. The amp output went to the 4 crossovers which fed the speakers. It has an RCA sub output which I connected to a self powered 8" sub that is in the trunk.
If your going to use coaxials in the rear then a crossover probably won't be needed, probably depends on the speaker you use. Some have a capacitor built in for the crossover. If they don't come with crossovers you don't need one.
More tomorrow. I'll throw up a pic of my install.

[geargrinder]

Good point on the depth thing jim. I forgot about that. My aftermarkets were kinda big and a C-hair too deep so I just made some relatively quick masonite rings to lift them out a tiny bit. There are generic speaker rings in 'normal' car audio sizes on eBay and other places that do exactly the same thing but you need to be sure if you go that route that there's enough forward clearance to the door card. The factory speakers have foam rings around them on the fronts which means there IS a little extra forward space you can steal, and that's exactly what I did, but you can't go too far forward either.

Yes for coaxials, they'll have an 'onboard crossover' (likely in form of a pretty primitive single capacitor...) so you can feed them 1 signal easily. Yes the fronts will need some sort of stand-alone crossover because the speakers are separate. Passive is easiest, and actually THAT is where matching speakers IS more of a good idea if you're not a real audio geek - aka a matched set of tweeter/woof that come w/ a crossover intended to work with both.

For example, I believe Jim has these (correct me if I'm wrong... although doesn't matter since they are only for illustration anyway...) , they are NLA but are at least an example of the kind of thing that makes for easy success - good quality, matched set with included crossover. If you find yourself something like these you're in good business.
http://www.bostonacoustics.com/US/Pr...ostonAcoustics)

Also yes you run the sub outs to the sub amp obv. If you are lucky, the N6 may have an option to software set one of the sub outputs as a mono combined sub signal so you don't have to run both cables... and your amp may only take one input anyway, so you'd have to figure out how to resolve that. Only feeding it one sub signal (R or L only) probably will sound fine 90% of the time if you had to do it, since vast majority of the time the bass signal won't be any different between left and right, but, having a true combined 'mono' signal is better. Using a simple Y connector frankly may work fine, but may not, theres situations where it could be bad for the headunit output circuits... certainly audiophools would go apoplectic at the idea of doing that however so its not good practice or advised.

Running the 5 (or 6) channels of RCA into the trunk will be one of the bigger hassles, as will sorting out which wire pairs go to which speaker. Color codes are all documented but tedious. The easiest RCA route is to run them down one of the sides behind the edge of the carpet after popping the trim off... I run all my cables under the carpet down the center tunnel, as its overall tidier that way but that's a huge hassle and I don't recommend it to most people.

[JimLev]

GG, yes Boston Acoustic SC-50 speakers in all 4 corners. They aren't available anymore.
I did go a bit overboard on the install by making it plug and play, figured that someday when I sell the car I'd stick the OE parts back in and move the amp to the next car which now isn't going to happen.
I sold the OE amp a few weeks ago, still have all of OE speakers in a box collecting dust.
The cases the crossovers were mounted in took up too much room so I ditched them and mounted their PC boards above the amp.

If you need a speaker depth measurement I can probably dig that up.

Dscn7956.jpg

Dscn7979.jpg

[philly98540]

Nice and tidy install!! I also used those Boston speakers when I changed mine out. I kept the original DSP amp though. Seems to work well enough for my taste, at least for now. A new fancy head unit and amp is tempting though...

[RedRover917]

How do the SC50 speakers compare in sound clarity to the Polk Audio speakers I’m aiming for? (Anyone heard both?). The Polks rms is 100 watts, while the SC50 is 65 watts (but I know watts aren’t everything).

Either way, the SC50 was my first choice for this e39 as well, my buddy has four he would sell me, but I know the original sets came with tweeters and crossovers (which he does not have), so I was going to pass on those since I didn’t want to deal with matching different tweeters/crossovers to them, and can’t find the complete sets online anywhere.

The bottom mounting depth for the Polk Audio DB5252 which are going into the front doors is 5.13cm (51.3mm), while for the DB522 going into the rears is 5.11cm (51.1mm).

The SC50 mounting depth is 55.5mm (if I’m not mistaking), so I think the Polks should fit fine, but would love love love a confirmed measurement for both front and rear oem speakers in an e39 just to be sure.

Also, the stock tweeters are 1”, but the Polk Audio tweeters are smaller, they are only 3/4”... So, will I need any extra trim or anything to mount them? And they are glued in, correct?

[RedRover917]

Geargrinder, I was wondering about which wiring route to take and was thinking down the driver’s side, under the door trim as you mentioned, but what about at the section of wire near the head unit?

Would I route in through the back of the dash and tucked under the steering wheel panel somewhere?

Is this pretty straight forward?

[JimLev]

RedRover, don't know what you have for DSP speakers, maybe different than my non-DSP system.
My SC50's are 2.188" deep, my old OE speakers are 2.417" deep.
Does your HU use wires to the trunk mounted amp for the audio signals like my non-DSP? If so use those to get the signal to your new amp.

[RedRover917]

Hmm that sounds like a great idea that would save so much time! I just hope that there would be enough cables to accommodate all of the channels.

...I believe in a DSP system, the head unit sends one signal to the amp, and the amp has built-in crossovers that feed all of the speakers, so I’m thinking I would be able to use these output wires from the DSP amp to power the new speakers, but afterall may still need to run wires from the head unit to the amp if I want to utilize the individual channel features of the Dynavin, especially the subwoofer outputs. I guess I’ll find out for sure when I get in there.

And regarding the mounting depth: Yup (2.18” = 55.5mm), so the Polks should fit fine since they are just a tad bit more shallow at 51mm. So sounds like the Polks will even have some room to lay some foam rings in between the speaker and the cutout.

[geargrinder]

Yeah the DSP vs non-DSP feed the amp differently.

The DSP car is wired with only 2 pairs (Left / Right) going to the DSP amp from the HU. The DSP then 'creates' the Front/Rear split itself. As well as indeed 'active crossovering' to create the 10 speakers worth of speaker-level signals, each of which indeed gets its own output pair of wires (aka 10 pairs).

So for a DSP replacement yes you have to wire up the signals to all the amps and you have only 2 pairs of factory wires to use. Therefore most guys just run all new RCA wires from front to rear since you have to go through that process anyway.

The non-DSP setup has the simple proper easy FL/FR/RL/RR pairs to the amp, which then also splits those into 10 outputs - 3 front 2 rear. So the non-DSP amp replacement is more straightforward.

Although as I think I mentioned in passing above somewhere, one fallback option in a DSP car is to only use those 2 pairs, then split the Left and Rear signals into your amp, and basically 'fix' the front/rear Fade using the amp gain settings. This works entirely fine however you lose any ability to work F/R fade on the fly. Honestly its probably fine - how often do you REALLY want to dynamically fuss w/ F/R fade... People have different views on how much rear fill they like IME but once its set to your preference do you really need to constantly tweak it? Your call. I ran 4 pairs of wire to the trunk but honestly especially given that i have the miniDSP which I could use for adjusting rear fade using the remote pre-sets, if I had it to over again I might take that shortcut.

Re: which side easier to run... Not the expert there since I didn't do it. I think the passenger side is supposed to be better, not sure if thats because there's less stuff running down the inside of the sills, or if its because the cross-over up front is easier. The latter is definitely a known benefit (much better landscape for crossing over behind the glovebox than behind the steering column with all the 'extra' stuff thats on the drivers side), unsure about the former howeever.