Help required with E90 Base sound system upgrade.

sir_bacharach · 05-27-2019, 02:19 PM

Hi,

I'm I'm a recovering cancer patient, so money's a bit scarce at the moment with me not working, so I'm looking for advice on an upgrade of my sounds system that's not gonna cost the earth.

Basically I have the Base sound system, but I've swapped out the standard head unit with a recent pioneer one.

I'm wanting change things bit by bit. I know the front speakers are meant to be wired to the subs with a poor circuit to split frequencies, and that it's all originally powered by the head unit and no amps.

What I'm looking to do is leave the door speakers as they are for now (but upgrade later to 2 way speakers rather than install tweeters)

But first I'd like some better subs under the seats and an amp.

I'm assuming I'd fit the amp in the back near the battery, run the phono cables from the head unit to the amp, then run wires to the subs under the seats.

I don't know if I can buy the amp for now and wire it up to the existing subs and whether that will make them sound a bit better for now as my head unit can separate the frequencies from the front speakers and subs anyway. Or would the original subs sound no better amped?

Then when I've got a bit more cash I'd like to get some better subs for under the seats if I need them, but again, I don't need the best of the best.

Finally, if the door speakers are still poop after all that, I'd like some advice on which door speakers to get.

All of the above doesn't have to be crazy powerful, just half decent, I know that makes it hard to gauge, but I just don't want to spend £1k on speakers.

Also if you can help me with what sizes I'll need to buy that would be great.

So size of the door speakers and if I need adaptors

and size and depth of the subs and adaptors if I need them.

I've had a look through some posts on here and there are some guides, but they seem to use rather expensive speakers. I'm just looking for a bit of a budget build. I used to have an Audi A3 Sline, I don't think it was BOSE, but it had really good speakers in it, so when I dropped my head unit in and put a sub in the boot it sounded ace, I'm just looking for something like that, not a crazy professional audio system.

ctuna · 05-27-2019, 04:23 PM

You will want a Technic Harness .
Many company's make BMW three way kits for
the front speakers withe true crossovers for the doors.
They are not cheap however.
There is a compatible speaker list in the audio build
sticky.

https://www.e90post.com/forums/showthread.php?t=343673

there are more than listed now but it won't be the standard stuff like pioneer or sony.

https://www.e90post.com/forums/showthread.php?t=641323

sir_bacharach · 05-28-2019, 07:23 AM

Thank you, I'll have a good read of these links.

I think as long as I get a good understanding of what fits, I'll know what to buy and can have a good scour and find something within my price range.

Ali-E90 · 05-29-2019, 07:32 AM

Since you're on a budget, and have already purchased the HU, I would do the amp next.
It would help to know up front if you want a dedicated trunk sub. You may not need it with a decent drop in kit (mine from audio systems is discontinued, but has decent bass without a trunk sub.... I still went with a trunk sub anyway because I like bass).

I'd go with a 5 or 6 channel amp that can run all/most of your car.
JL 600/6 is popular. I use a JL 700/5, bridging my underseat woofers to the sub channel of that amp, then using a separate dedicated amp for my trunk sub.

sir_bacharach · 05-30-2019, 11:58 AM

Hi,

More questions!

I've managed to find some earthquake SWS under-seat subs second hand and an appropriate 2 channel amp. I'm not bothered about amping the door speakers as when I had my Audi I was quite happy with how loud/powerful they were (the head unit is 50w per channel)

I'm going to start with just the under seat subs for now and have the wires I need already.

I was wondering if you know the best way to run the wires from the under seat subs to the boot? how will I get the wires through to the boot, what do I need to remove to channel them through etc?

I'm assuming I'd just put some electricians tape over the original connectors for the subs, then run wires to the boot where the amp will be located, then wire the amp up to the battery.

Then the amp will have the phono connectors and wires run back to the head unit where it will plug into the sub outputs along with the remote wire.

That way the head unit will power the standard front and rear door speakers (it's 50w per channel, so should be OK) and then the sub will feed the amp to the two under seat subs. The head unit has low and high pass filters so I can do all that from the head unit.

So yeah, my main concern was how to get the wires from the subs to the boot. Any advice would be massively appreciated.

Oh and can I wire the earth of the amp directly to the battery earth or should it always be a ground down bit of metal on the car shell? I hate scraping paint off my car, just asking for rust. haha.

ctuna · 05-30-2019, 12:06 PM

sir_bacharach · 05-30-2019, 12:21 PM

I'm guessing the Technics Harness is more geared toward people keeping their stock head unit though and mine is after market and has the pre amp outputs. I think I'd rather try and get the new wires to the boot direct from the subs.

I think what I might try is getting the seats out, taking out the trim near the door sills at both sides then channelling speaker wire from the subs to the trim at the bottom of the door then along to the boot down the sides of the car. I didn't think of that initially, but that might be the best course of action.

Ali-E90 · 06-03-2019, 11:09 AM

Quote:

Originally Posted by sir_bacharach

I'm guessing the Technics Harness is more geared toward people keeping their stock head unit though and mine is after market and has the pre amp outputs. I think I'd rather try and get the new wires to the boot direct from the subs.

Yes you are right... I didn't use a technic harness for this reason also, to run RCAs directly to amp from my aftermarket HU.

I had a shop do that initial work for me, but I imagine there are guides here to help route wires to the boot etc.

ctuna · 06-03-2019, 01:12 PM

Technic make three different harnesses for the Base system.
The minimum harness would probably take care of the front
doors and floors as far as running those to and amp in the Trunk
without cutting or splicing.(dependent on year of car)

connectors
http://www.e90post.com/forums/showpo...9&postcount=19
http://www.e90post.com/forums/showth...ower+Connector
connectors1
http://www.e90post.com/forums/showpo...9&postcount=19

Null_Error · 06-03-2019, 01:57 PM

I'm in a similar situation. I just want to add OEM tweeters and already have an aftermarket android head so is the JL 600/6 still the best option for such a simple set up or is there anything better / cheaper for base OEM + tweeters. I've read through a lot of the threads but most of them seem to want a better system then what I require.

ctuna · 06-03-2019, 05:33 PM

Why the Jl XD 600/6 was a good choice.
It has 6 channels (and there are 6 basic speaker positions)
It allows eq on each of the 3 pairs of channels
at the amp .
It fits in the stock amp location or a few others.
Its effecient.
JL makes quality amps
Also above 50 watts a channel and to get some good sound
you need to think about changing all the speakers at least in
the front.

If you can find something that fits all of the above or
the portions that matter to you go for it.

sir_bacharach · 06-04-2019, 08:46 AM

Thanks all.

I've purchased 2 x EarthQuake SWS-8 Subs to replace the under seat subs

I've also purchased a Fli 800 Watt amp with the following Specs

Type: 4/3/2 Channel Stereo
Bass boost provides up to 12dB at 45Hz
High and low level inputs
All new Fli design for durability and style
Onboard crossovers
Auto detect switch on function
MAX Power: 800 watts RMS
4 Ohms Stereo: 4 x 80 watts RMS
2 Ohms Stereo: 4 x 100 watts RMS
4 Ohms Mono: 2 x 200 watts RMS

The subs are 150 Watts RMS (300 Watts Max whatever that means)

So I only have two questions left now for the time being.

How do I remove the boot/trunk lining to find a decent earthing point for the amp? I've read it should never be earthed direct to the battery as you get interference that way.

And secondly, do I wire up the subs as stereo in which case, how do I wire it up?

The amp has 4 channels which are labelled FR, FL, RR, RL.
Now I know you can bridge left and right for a sub, which will make it mono, but can you bridge front and back L and front and back R so you can keep the Wattage but also keep the stereo Subs or will that cause damage?

I downloaded the manual and there is nothing to suggest you can bridge front and back on a 4 channel amp, which means that if I wanted stereo I'd have to have 80 Watts (as that's what the amp is per channel, but the SUBS are 150), but if I go for Mono bridged, bridging the fronts to one sub and the backs to another I'll get max of 200 Watts, which of course I'll have to tone down so as not to blow the subs, but at least I could get more power from them.

Does that sound about right or is there a way of bridging the front and back channels of each side together as above?

Most important thing though is how do I get the boot lining out as I can't find any videos on youtube for it.

ctuna · 06-04-2019, 01:25 PM

I am grounded and hooked up directly to the battery and it causes
no problems with my system. And its a kit from one of the most
respected Hi End BMW installers on the the West Coast of the US.

There are plenty of alternate ground points .

electical e90 pdf
http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU

If you want to know what you can do with your amp read the manual
and or call the manufacturer.

Better to keep the underseats in stereo in my opinion.

yeah you may get 200 watts in series but its spread across two speakers.
and you loose stereo.

soulgod123 · 06-05-2019, 02:40 AM

you should have started with replacing front speakers with components, leaving underseats as it is and rears than adding sub in the trunk, just dont buy cheap fronts, forget about rears as you are on budged.

Emilime75 · 06-05-2019, 06:51 AM

Why would you lose stereo? If you're bridging both pairs of a 4 ch. amp you end up with 2. Guess how many channels you need for stereo.

kaigoss69 · 06-05-2019, 07:52 AM

There are 3-way sets available in Europe from Jehnert, Gladen, Audio Systems, just to name a few, all of which I believe can be operated in 2 channel mode, so they come with passive crossovers that split the frequencies between the speaker sets, and you would only need a 2-channel amp to drive them. This is the best option when you are on a tight budget.

ctuna · 06-05-2019, 11:16 AM

Bridging is gives more power but running in series distributes
that power across a greater load and also only allows one
channel across that load.
All those speakers kaigoss69 mentioned are great but not cheap.
Getting away from powering all the fronts of one channel per side
is a better goal than powering the back seats at all.

bluewater328 · 06-05-2019, 01:19 PM

Quote:

Originally Posted by ctuna

...Getting away from powering all the fronts of one channel per side
is a better goal than powering the back seats at all.

Truth

kaigoss69 · 06-05-2019, 08:23 PM

Quote:

Originally Posted by ctuna

All those speakers kaigoss69 mentioned are great but not cheap.

Not really, for example the Jehnert system is less than 500 Euros.

https://www.jehnert.de/en/shop/doorb...-3-5-7-series/

Others you can probably find even cheaper. I agree that if you have a 4 channel amp, bi-amping is the way to go.

ctuna · 06-05-2019, 08:49 PM

Yeah but the OP probably doesn't want to spend that
on the whole system.

sir_bacharach · 06-06-2019, 11:32 AM

Thanks for all the advice.
I'm going to go with bridging the two under seat subs from the amp in the boot, I can always experiment with turning amping them stereo at the lower wattage without bridging as all the wires will be in the back.

I have all the gear ready to go now, just received the Earthquake SWS-8 speakers with fitting kits, got all the wiring and got the Fli 800 Watt 4 Channel amp ready to go.

Can't fit it immediately as I'm recovering from a bone marrow transplant and I'm weak as piss at the moment.

My headunit is a Pioneer AVIC F70-DAB and outputs 50 Watts Per Channel, I had it in my previous car which was an Audi A3 and it powered those speakers quite nicely but it did have tweeters on the mirror trims, so I'm going to go with getting some cheap ish speakers to go in the doors to replace the standard ones.

The ones I'm looking at are Vibe Slick 4" Speakers which are 2 way and and all in one (as my E90 doesn't have tweeters stock). They're 50 Watts RMS, 150 Peak. I've ordered some speaker adaptors and I've checked the depth and they should go in, also ordered some speaker adaptor wires so that I don't have to clip the original BMW cabling, I want it all kept intact so when I come to sell it I can take them all out and put it back to standard.

I thought later on, if I'm not happy with the range of sound when I have the money I can move those front speakers to the back doors and put some components in the front, but I don't know if it's doable to have components powered off the head unit or whether they really need to be amped.

My question now is that there's a minimum Wattage rating of 35 Watts RMS on the door speakers I'm looking at. I understand that means that no sound will come out of them until the head unit pumps out 35 watts RMS (is that correct?)

If so does that mean that if I were to choose speakers that had a lower minimum wattage rating, those lower ones would be louder if I turned the volume all the way up, or is it irrelevant to the maximum volume the speaker will output and only effects when the speaker begins to make noise?

Also, is there some way I can turn on email notifications to my thread so when one of you guys reply I'm notified? I can't seem to see an option.

Really appreciate the help by the way everyone. I've always liked my audio, but it's normally only ever been a case of me having a decent stereo and fitting a sub in the back, which was much easier in previous cars I had because the speakers that were in them were already good enough for me, but these are trash.

ctuna · 06-06-2019, 11:50 AM

You need to study some electrical theory.
A lot of it.
Especially with regard to speakers .
Wattage ratings are just about the amount of power a speaker
can handle . Two things are of concern the maximum it can
handle and amount it needs to sound as good as it can.
In general you want to match the amp wattage to the amount the
manufacturer stated for average wattage and not exceed maximum
but there is a lot of play with this.
One of the other parameters is efficiency how much sound pressure
does the speaker produce for a given amount of Input power.
The one that most people new to stereo scratch there heads over
it Impedence. There are 2 ohm 4 ohm and sometimes 8 ohm speakers.
A 2 ohm speaker will allow and amp to put out more power than 4 ohm
or 8 ohm . If you drop a 4 ohm speaker into a previously occupied by
a 2 ohm speaker your max volume will drop by about 1/3 to 1/2.

http://www.prestonelectronics.com/audio/Impedance.htm

https://www.google.com/search?client...j0.12iQEwKvze0

05-27-2019, 02:19 PM	#1
sir_bacharach New Member 1 Rep 17 Posts Drives: BMW 330d M Sport Join Date: May 2019 Location: United Kingdom iTrader: (0)	Help required with E90 Base sound system upgrade. Hi, I'm I'm a recovering cancer patient, so money's a bit scarce at the moment with me not working, so I'm looking for advice on an upgrade of my sounds system that's not gonna cost the earth. Basically I have the Base sound system, but I've swapped out the standard head unit with a recent pioneer one. I'm wanting change things bit by bit. I know the front speakers are meant to be wired to the subs with a poor circuit to split frequencies, and that it's all originally powered by the head unit and no amps. What I'm looking to do is leave the door speakers as they are for now (but upgrade later to 2 way speakers rather than install tweeters) But first I'd like some better subs under the seats and an amp. I'm assuming I'd fit the amp in the back near the battery, run the phono cables from the head unit to the amp, then run wires to the subs under the seats. I don't know if I can buy the amp for now and wire it up to the existing subs and whether that will make them sound a bit better for now as my head unit can separate the frequencies from the front speakers and subs anyway. Or would the original subs sound no better amped? Then when I've got a bit more cash I'd like to get some better subs for under the seats if I need them, but again, I don't need the best of the best. Finally, if the door speakers are still poop after all that, I'd like some advice on which door speakers to get. All of the above doesn't have to be crazy powerful, just half decent, I know that makes it hard to gauge, but I just don't want to spend £1k on speakers. Also if you can help me with what sizes I'll need to buy that would be great. So size of the door speakers and if I need adaptors and size and depth of the subs and adaptors if I need them. I've had a look through some posts on here and there are some guides, but they seem to use rather expensive speakers. I'm just looking for a bit of a budget build. I used to have an Audi A3 Sline, I don't think it was BOSE, but it had really good speakers in it, so when I dropped my head unit in and put a sub in the boot it sounded ace, I'm just looking for something like that, not a crazy professional audio system. Attached Images Last edited by sir_bacharach; 06-06-2019 at 11:33 AM.. Reason: Add an Image
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05-27-2019, 04:23 PM	#2
ctuna Lieutenant General 1911 Rep 13,101 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	You will want a Technic Harness . Many company's make BMW three way kits for the front speakers withe true crossovers for the doors. They are not cheap however. There is a compatible speaker list in the audio build sticky. https://www.e90post.com/forums/showthread.php?t=343673 there are more than listed now but it won't be the standard stuff like pioneer or sony. https://www.e90post.com/forums/showthread.php?t=641323 Last edited by ctuna; 05-27-2019 at 04:33 PM..
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05-28-2019, 07:23 AM	#3
sir_bacharach New Member 1 Rep 17 Posts Drives: BMW 330d M Sport Join Date: May 2019 Location: United Kingdom iTrader: (0)	Thanks! Thank you, I'll have a good read of these links. I think as long as I get a good understanding of what fits, I'll know what to buy and can have a good scour and find something within my price range.
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05-29-2019, 07:32 AM	#4
Ali-E90 Colonel 379 Rep 2,365 Posts Drives: 2007 E90 323i (Cdn) Join Date: May 2013 Location: Toronto, Canada iTrader: (3) Garage List 2008 BMW M3 [8.00] 2007 BMW 323i [8.50]	Since you're on a budget, and have already purchased the HU, I would do the amp next. It would help to know up front if you want a dedicated trunk sub. You may not need it with a decent drop in kit (mine from audio systems is discontinued, but has decent bass without a trunk sub.... I still went with a trunk sub anyway because I like bass). I'd go with a 5 or 6 channel amp that can run all/most of your car. JL 600/6 is popular. I use a JL 700/5, bridging my underseat woofers to the sub channel of that amp, then using a separate dedicated amp for my trunk sub. __________________ Check out my Mod Thread Here
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05-30-2019, 11:58 AM	#5
sir_bacharach New Member 1 Rep 17 Posts Drives: BMW 330d M Sport Join Date: May 2019 Location: United Kingdom iTrader: (0)	Hi, More questions! I've managed to find some earthquake SWS under-seat subs second hand and an appropriate 2 channel amp. I'm not bothered about amping the door speakers as when I had my Audi I was quite happy with how loud/powerful they were (the head unit is 50w per channel) I'm going to start with just the under seat subs for now and have the wires I need already. I was wondering if you know the best way to run the wires from the under seat subs to the boot? how will I get the wires through to the boot, what do I need to remove to channel them through etc? I'm assuming I'd just put some electricians tape over the original connectors for the subs, then run wires to the boot where the amp will be located, then wire the amp up to the battery. Then the amp will have the phono connectors and wires run back to the head unit where it will plug into the sub outputs along with the remote wire. That way the head unit will power the standard front and rear door speakers (it's 50w per channel, so should be OK) and then the sub will feed the amp to the two under seat subs. The head unit has low and high pass filters so I can do all that from the head unit. So yeah, my main concern was how to get the wires from the subs to the boot. Any advice would be massively appreciated. Oh and can I wire the earth of the amp directly to the battery earth or should it always be a ground down bit of metal on the car shell? I hate scraping paint off my car, just asking for rust. haha. Last edited by sir_bacharach; 05-30-2019 at 12:02 PM.. Reason: Added more explanation.
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05-30-2019, 12:06 PM	#6
ctuna Lieutenant General 1911 Rep 13,101 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Best to buy a Technic Harness. http://www.e90post.com/forums/showth...1#post16679904 Base System Upgrades http://www.e90post.com/forums/showthread.php?t=445266 http://www.1addicts.com/forums/showthread.php?t=634957 http://f30.bimmerpost.com/forums/sho....php?t=1003810 http://www.e90post.com/forums/showthread.php?t=822366 http://www.e90post.com/forums/showthread.php?t=581379 http://www.e90post.com/forums/showthread.php?t=451941 http://www.e90post.com/forums/showthread.php?t=540954 http://www.e90post.com/forums/showth...ghlight=Dotech http://www.e90post.com/forums/showthread.php?t=495855 http://www.e90post.com/forums/showthread.php?t=494299 http://www.diymobileaudio.com/forum/...morel-jbl.html http://www.e90post.com/forums/showth...ht=amp+upgrade http://www.bimmerfest.com/forums/sho...d.php?t=550771 http://www.e90post.com/forums/showth...1#post16679904 http://www.e90post.com/forums/attach...1&d=1411521234 http://www.e90post.com/forums/showthread.php?t=1378833 base system wiring pre/post 3/09 http://www.e90post.com/forums/attach...1&d=1411521234 https://www.google.com/url?sa=t&rct=...tDpLJPcGkw_ui_ http://www.e90post.com/forums/showth...1#post16679904 BMW stereo types http://www.e90post.com/forums/showthread.php?t=352586 http://www.e90post.com/forums/attach...2&d=1266451970 http://www.e90post.com/forums/attach...2&d=1260829447 http://www.e90post.com/forums/showthread.php?t=343673 http://www.e90post.com/forums/showthread.php?t=138949 http://www.e90post.com/forums/attach...1&d=1209780605 http://www.e90post.com/forums/attach...1&d=1209780865 http://www.e90post.com/forums/showthread.php?t=641323 http://bmwcoders.com/forum/3-er-8/bm...1-e92-e93-291/ http://technicpnp.com/menuDiagrams/d...e90_92_93.html http://www.musicarnw.com/page-2/ http://www.e90post.com/forums/attach...3&d=1169133185 http://www.e90post.com/forums/attach...4&d=1278871872
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05-30-2019, 12:21 PM	#7
sir_bacharach New Member 1 Rep 17 Posts Drives: BMW 330d M Sport Join Date: May 2019 Location: United Kingdom iTrader: (0)	I'm guessing the Technics Harness is more geared toward people keeping their stock head unit though and mine is after market and has the pre amp outputs. I think I'd rather try and get the new wires to the boot direct from the subs. I think what I might try is getting the seats out, taking out the trim near the door sills at both sides then channelling speaker wire from the subs to the trim at the bottom of the door then along to the boot down the sides of the car. I didn't think of that initially, but that might be the best course of action.
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06-03-2019, 01:12 PM	#9
ctuna Lieutenant General 1911 Rep 13,101 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Technic make three different harnesses for the Base system. The minimum harness would probably take care of the front doors and floors as far as running those to and amp in the Trunk without cutting or splicing.(dependent on year of car) connectors http://www.e90post.com/forums/showpo...9&postcount=19 http://www.e90post.com/forums/showth...ower+Connector connectors1 http://www.e90post.com/forums/showpo...9&postcount=19
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06-03-2019, 01:57 PM	#10
Null_Error New Member 0 Rep 5 Posts Drives: BMW 335xi Join Date: May 2019 Location: Mass iTrader: (0)	I'm in a similar situation. I just want to add OEM tweeters and already have an aftermarket android head so is the JL 600/6 still the best option for such a simple set up or is there anything better / cheaper for base OEM + tweeters. I've read through a lot of the threads but most of them seem to want a better system then what I require.
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06-03-2019, 05:33 PM	#11
ctuna Lieutenant General 1911 Rep 13,101 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Why the Jl XD 600/6 was a good choice. It has 6 channels (and there are 6 basic speaker positions) It allows eq on each of the 3 pairs of channels at the amp . It fits in the stock amp location or a few others. Its effecient. JL makes quality amps Also above 50 watts a channel and to get some good sound you need to think about changing all the speakers at least in the front. If you can find something that fits all of the above or the portions that matter to you go for it.
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06-04-2019, 08:46 AM	#12
sir_bacharach New Member 1 Rep 17 Posts Drives: BMW 330d M Sport Join Date: May 2019 Location: United Kingdom iTrader: (0)	Thanks all. I've purchased 2 x EarthQuake SWS-8 Subs to replace the under seat subs I've also purchased a Fli 800 Watt amp with the following Specs Type: 4/3/2 Channel Stereo Bass boost provides up to 12dB at 45Hz High and low level inputs All new Fli design for durability and style Onboard crossovers Auto detect switch on function MAX Power: 800 watts RMS 4 Ohms Stereo: 4 x 80 watts RMS 2 Ohms Stereo: 4 x 100 watts RMS 4 Ohms Mono: 2 x 200 watts RMS The subs are 150 Watts RMS (300 Watts Max whatever that means) So I only have two questions left now for the time being. How do I remove the boot/trunk lining to find a decent earthing point for the amp? I've read it should never be earthed direct to the battery as you get interference that way. And secondly, do I wire up the subs as stereo in which case, how do I wire it up? The amp has 4 channels which are labelled FR, FL, RR, RL. Now I know you can bridge left and right for a sub, which will make it mono, but can you bridge front and back L and front and back R so you can keep the Wattage but also keep the stereo Subs or will that cause damage? I downloaded the manual and there is nothing to suggest you can bridge front and back on a 4 channel amp, which means that if I wanted stereo I'd have to have 80 Watts (as that's what the amp is per channel, but the SUBS are 150), but if I go for Mono bridged, bridging the fronts to one sub and the backs to another I'll get max of 200 Watts, which of course I'll have to tone down so as not to blow the subs, but at least I could get more power from them. Does that sound about right or is there a way of bridging the front and back channels of each side together as above? Most important thing though is how do I get the boot lining out as I can't find any videos on youtube for it.
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06-04-2019, 01:25 PM	#13
ctuna Lieutenant General 1911 Rep 13,101 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	I am grounded and hooked up directly to the battery and it causes no problems with my system. And its a kit from one of the most respected Hi End BMW installers on the the West Coast of the US. There are plenty of alternate ground points . electical e90 pdf http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja http://www.google.com/url?sa=t&rct=j...85464276,d.cGU http://www.google.com/url?sa=t&rct=j...85464276,d.cGU If you want to know what you can do with your amp read the manual and or call the manufacturer. Better to keep the underseats in stereo in my opinion. yeah you may get 200 watts in series but its spread across two speakers. and you loose stereo. Last edited by ctuna; 06-04-2019 at 06:03 PM..
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06-05-2019, 02:40 AM	#14
soulgod123 Enlisted Member 6 Rep 41 Posts Drives: bmw 318lci 2008 Join Date: Jan 2017 Location: United Kingdom iTrader: (0)	you should have started with replacing front speakers with components, leaving underseats as it is and rears than adding sub in the trunk, just dont buy cheap fronts, forget about rears as you are on budged.
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06-05-2019, 06:51 AM	#15
Emilime75 Colonel 1209 Rep 2,476 Posts Drives: 2010 335i E92 LeMans Blue Join Date: Dec 2017 Location: Merica! iTrader: (1)	Why would you lose stereo? If you're bridging both pairs of a 4 ch. amp you end up with 2. Guess how many channels you need for stereo.
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06-05-2019, 07:52 AM	#16
kaigoss69 Brigadier General 300 Rep 3,969 Posts Drives: '08 335i Join Date: Jul 2008 Location: JAX iTrader: (6)	There are 3-way sets available in Europe from Jehnert, Gladen, Audio Systems, just to name a few, all of which I believe can be operated in 2 channel mode, so they come with passive crossovers that split the frequencies between the speaker sets, and you would only need a 2-channel amp to drive them. This is the best option when you are on a tight budget. __________________ Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa OT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
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06-05-2019, 11:16 AM	#17
ctuna Lieutenant General 1911 Rep 13,101 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Bridging is gives more power but running in series distributes that power across a greater load and also only allows one channel across that load. All those speakers kaigoss69 mentioned are great but not cheap. Getting away from powering all the fronts of one channel per side is a better goal than powering the back seats at all.
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06-05-2019, 08:49 PM	#20
ctuna Lieutenant General 1911 Rep 13,101 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Yeah but the OP probably doesn't want to spend that on the whole system.
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06-06-2019, 11:32 AM	#21
sir_bacharach New Member 1 Rep 17 Posts Drives: BMW 330d M Sport Join Date: May 2019 Location: United Kingdom iTrader: (0)	Thanks for all the advice. I'm going to go with bridging the two under seat subs from the amp in the boot, I can always experiment with turning amping them stereo at the lower wattage without bridging as all the wires will be in the back. I have all the gear ready to go now, just received the Earthquake SWS-8 speakers with fitting kits, got all the wiring and got the Fli 800 Watt 4 Channel amp ready to go. Can't fit it immediately as I'm recovering from a bone marrow transplant and I'm weak as piss at the moment. My headunit is a Pioneer AVIC F70-DAB and outputs 50 Watts Per Channel, I had it in my previous car which was an Audi A3 and it powered those speakers quite nicely but it did have tweeters on the mirror trims, so I'm going to go with getting some cheap ish speakers to go in the doors to replace the standard ones. The ones I'm looking at are Vibe Slick 4" Speakers which are 2 way and and all in one (as my E90 doesn't have tweeters stock). They're 50 Watts RMS, 150 Peak. I've ordered some speaker adaptors and I've checked the depth and they should go in, also ordered some speaker adaptor wires so that I don't have to clip the original BMW cabling, I want it all kept intact so when I come to sell it I can take them all out and put it back to standard. I thought later on, if I'm not happy with the range of sound when I have the money I can move those front speakers to the back doors and put some components in the front, but I don't know if it's doable to have components powered off the head unit or whether they really need to be amped. My question now is that there's a minimum Wattage rating of 35 Watts RMS on the door speakers I'm looking at. I understand that means that no sound will come out of them until the head unit pumps out 35 watts RMS (is that correct?) If so does that mean that if I were to choose speakers that had a lower minimum wattage rating, those lower ones would be louder if I turned the volume all the way up, or is it irrelevant to the maximum volume the speaker will output and only effects when the speaker begins to make noise? Also, is there some way I can turn on email notifications to my thread so when one of you guys reply I'm notified? I can't seem to see an option. Really appreciate the help by the way everyone. I've always liked my audio, but it's normally only ever been a case of me having a decent stereo and fitting a sub in the back, which was much easier in previous cars I had because the speakers that were in them were already good enough for me, but these are trash.
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06-06-2019, 11:50 AM	#22
ctuna Lieutenant General 1911 Rep 13,101 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	You need to study some electrical theory. A lot of it. Especially with regard to speakers . Wattage ratings are just about the amount of power a speaker can handle . Two things are of concern the maximum it can handle and amount it needs to sound as good as it can. In general you want to match the amp wattage to the amount the manufacturer stated for average wattage and not exceed maximum but there is a lot of play with this. One of the other parameters is efficiency how much sound pressure does the speaker produce for a given amount of Input power. The one that most people new to stereo scratch there heads over it Impedence. There are 2 ohm 4 ohm and sometimes 8 ohm speakers. A 2 ohm speaker will allow and amp to put out more power than 4 ohm or 8 ohm . If you drop a 4 ohm speaker into a previously occupied by a 2 ohm speaker your max volume will drop by about 1/3 to 1/2. http://www.prestonelectronics.com/audio/Impedance.htm https://www.google.com/search?client...j0.12iQEwKvze0 Last edited by ctuna; 06-06-2019 at 11:57 AM..
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