E60Rules

I'll try to answer, but keep in mind I'm not a professional, just an E60 music enjoying Dutchman

1) as speakers are driven with the signal, it's a high level signal, already being amped, and thus high-level (of cause able to listen music at low levels but amped signal is always high level, it should be nicer to grab somewhere a low level (often cinch) signal, but lacking it in my E60 is exactly this post about.
2) I my story I instruct to grab left and right, so you don't miss any bass signal, sometimes coming from right, sometimes from left.
But to be honoust, I didn't want also te remove my driverseat, and just grabbed the signal from my right mini-sub, which is not perfect, but good enough. Another disadvantage from using 1 signal instead of 2 is some amplifiers don't receive enough power from just 1 side, resulting in not enough bass even at maximum power of the amp or amped subwoofer.
3) I don't know which versions there are, I'm very experiences with home loudspeakers (build them), but know almost nothing about impedances used with car speakers, but be carefull with low impedances, it will be like in home speakers, to low impedance will drain a lot of current (ampere's) from any amp, with CAN result in overheating or even damage. 4ohm is as far as I know the regular car speaker impedance
4) see 3
5) I don't want to swap your SWS plan, but am wondering why using the SWS8 speaker, they're relative expensive, and I doubt they will result in enough pleasure, as far as I read they're ment as upgrade for logic7 systems, but or the simple audio system as we have results in a well balanced system when upgrading to bigger subs under the seats with a seperate amp am I not sure about.
The big plus of your idea is you don't waste room anywhere for a seperate sub box, only somewhere an amp.
But that's why I can easily take out my sub because I uses connectors for power and signals.
I only want to say that when buying amp and SWS8 subs you pay 4 times the money as a pretty good 30cm subwoofer of middle brand costs.

It's only my opinion, always of cause be free to follow your own ideas, in Holland we say, same good friends

sd_dracula

Thanks for the input
Yes I know getting 2xSWS + amp is more expensive but I really like to keep the OEM look, and since I have no ski-port and my rear seats aren't foldable, it would be a lot of work to get the sound out of the boot.
How did you tackle that problem?

E60Rules

You're right, replacing subs is the best look

I have to keep open my ski-door, when closed I hear to much rattling parts and to less bass

Nice black car you have, I figured out I can click those little images

Blk5TT

Nice write-up n pics

sd_dracula

Thanks
Just had another idea, from another forum.
What if I am to take the high level output of the 2 rear shelf speakers, feed into a http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190535351217&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en (this seems to be the exact one Technic uses in his harness) and then pass it into the amp?
Would that cause distortion at high volume?

E60Rules

Somewhere on this forum some people say only subwoofers receives the lowest frequencies, rear shelf speakers are only being feeded with mid and high freq, thus unusual for sub-amping.
For the people who want a closer look to my black 19" alpina's (front 8,5x19 255/35/19 (realy wide for front, best pavement protection) back 9,5 x 19 275/30/19 all Vredestein Ultrac Sessanta tyres).

E60Rules

Somewhere on this forum some people say only subwoofers receives the lowest frequencies, rear shelf speakers are only being feeded with mid and high freq, thus unusual for sub-amping.
For the people who want a closer look to my black 19" alpina's (front 8,5x19 255/35/19 (realy wide for front, best pavement protection) back 9,5 x 19 275/30/19 all Vredestein Ultrac Sessanta tyres).

sd_dracula

Awesome wheels
About the rear shelf, yes they are high but won't the converter take care of that and make it low for the amp?
If I was to just tap the underseat subs, surely that is high also due to it coming from the "amp" in the head unit, so I will need a LOC also?

E60Rules

keep in mind that high level signal has nothing to do with high frequency signal

High level = high power (and higher voltage, easily between 10 and 40 volt maximum)
low level = low power (and low voltage, some 1,5 volt maximum)

High frequency = high tones
Low frequency = bass signals you can feel

Knowing this you will understand it's not possible for any elektronic device to create low frequency (bass signals) from a wire which doesn't contain low freq at all.
In other words, if the bass signal (base drum in music) is not leaded to the shelf speakers, it isn't there.
a Loc only lowers voltage, and has nothing to do with frequency.
a Loc is a high level to low level converter, no more no less

I hope this make things clear to you

sd_dracula

Ok thanks for the explanation, it is clearer now.
I guess I assumed that since the front door speakers are fed the same signal as the under seat subs (since they are wired in parallel) the rear's would also get the same signal, which is not whats happening.
The standard audio front door speakers are able to put out some bass also since after replacing them with L7 ones, the bass has been dampened by a lot.
So the best way is to still tap into the sub cables and feed that into an amp that can do lowpass filtering right? Something like this perhaps? It seems to tick all the boxes.