Subwoofer Removal

[bmw>benz]

I am looking to upgrade the stock subwoofers with Earthquake SWS drop in replacements. This swap has been done on various e9xs and e6x cars but I cannot seem to find anything on the e89.

Does anyone know the process of pulling apart the interior (rear parcel) so that I can get access to the subwoofer? I have searched since I got the car 1 month ago and havent found much to go off of.

[bmw>benz]

Photo for reference

[davis449]

Most of the bass from the premium sound option's system comes from the footwell woofers. I don't think you're going to achieve much by just swapping those two behind the seats. You're going to want amplify them independently. Since you're going to be in there anyway, it's little additional effort to put in an second amp near the stock one (that's where mine is for my trunk installed sub is) using Technic's 677 harness. Whatever little sound they produce in their existing configuration, both in Surround and non-Surround mode, won't be missed. They don't even produce 1/4 of the bass the stock underseats do in the 1 and 3 series. Most everyone that installs any drop in replacements either does or wishes they had amplified them even in those cars. Where you're headed in terms of install location is exactly what I would do if I wasn't leasing my car.

[bmw>benz]

Originally Posted by davis449

Most of the bass from the premium sound option's system comes from the footwell woofers. I don't think you're going to achieve much by just swapping those two behind the seats. You're going to want amplify them independently. Since you're going to be in there anyway, it's little additional effort to put in an second amp near the stock one (that's where mine is for my trunk installed sub is) using Technic's 677 harness. Whatever little sound they produce in their existing configuration, both in Surround and non-Surround mode, won't be missed. They don't even produce 1/4 of the bass the stock underseats do in the 1 and 3 series. Most everyone that installs any drop in replacements either does or wishes they had amplified them even in those cars. Where you're headed in terms of install location is exactly what I would do if I wasn't leasing my car.

I checked real OEM.The subs behind the seats are 8 inch subs. The same 8 inch subs found in 3,4,5,6,7,x3,x5 and x6 for the past 10 years. IIRC the ones in the door are 6 inch.

This swap has been well documented on the e9xs and is good for more than 3 DBs with the stock amplifier. I have already done this swap on an x5 and 3 e92s with excellent results. Of course sound is all subjective but for my situation this solution fits the bill. I'm looking for something relatively stock and don't want to do anything in terms of amplification.

[davis449]

Originally Posted by bmw>benz

I checked real OEM.The subs behind the seats are 8 inch subs. The same 8 inch subs found in 3,4,5,6,7,x3,x5 and x6 for the past 10 years. IIRC the ones in the door are 6 inch.

This swap has been well documented on the e9xs and is good for more than 3 DBs with the stock amplifier. I have already done this swap on an x5 and 3 e92s with excellent results. Of course sound is all subjective but for my situation this solution fits the bill. I'm looking for something relatively stock and don't want to do anything in terms of amplification.

I, too, have heard of people happy with drop in replacements in 1 and 3 series HK sound systems with no additional amplification. Maybe I need to clarify a bit. What I am saying is that the premium audio option in the Z4 is not a Harmon Kardon or any other lower option system. The 8" subs behind the seats don't perform the same bass production that they usually do in the other BMW's you listed. They are practically inaudible in non-surround mode, and not much better in surround. The processing and equalization is not the same in this car as it is in the others. As I stated before, the bass (well, really, midbass) comes from the footwell speakers (those 6 inchers). Therefore, if you swap the ones behind the seats with upgrades, you won't get much, if anything, out of them because they are not sent signal the same way as in the other applications you listed. Swapping them out will not overcome the fact that the amp doesn't really use them. Does that make sense?

[fmorelli]

BTW 3db gain with a stock amplifier means the a speaker efficiency improvement that would be the equivalent of doubling amplifier power on the stock speakers (if they could handle the power increase).

Bavsound, for which people have varying opinions, does not change any of the woofers on these cars, as part of their kit. Now they'll sell you the rear woofers if you want. Given they are in the business, so-to-speak, I'd love to know why they don't change the rear woofers or offer footwell speakers on the E89. I have the Bavsound kit and hope to do the install soon.

Filippo

[bmw>benz]

Originally Posted by fmorelli

BTW 3db gain with a stock amplifier means the a speaker efficiency improvement that would be the equivalent of doubling amplifier power on the stock speakers (if they could handle the power increase).

Bavsound, for which people have varying opinions, does not change any of the woofers on these cars, as part of their kit. Now they'll sell you the rear woofers if you want. Given they are in the business, so-to-speak, I'd love to know why they don't change the rear woofers or offer footwell speakers on the E89. I have the Bavsound kit and hope to do the install soon.

Filippo

3db gain does not necessarily mean the amp is working harder. There is much more to it than that. For example, different subwoofers resonate at different frequency ranges. Meaning their output increases in a specific band width. Everything from dustcap weight, to surround stiffness can affect a subwoofers resonance.

The Earthquake SWS is actually a patented design used under license. Bavsound probably is not licensed. The motor on the SWS is HUGE in comparison to the dinky stock ones.

[bmw>benz]

Originally Posted by davis449

I, too, have heard of people happy with drop in replacements in 1 and 3 series HK sound systems with no additional amplification. Maybe I need to clarify a bit. What I am saying is that the premium audio option in the Z4 is not a Harmon Kardon or any other lower option system. The 8" subs behind the seats don't perform the same bass production that they usually do in the other BMW's you listed. They are practically inaudible in non-surround mode, and not much better in surround. The processing and equalization is not the same in this car as it is in the others. As I stated before, the bass (well, really, midbass) comes from the footwell speakers (those 6 inchers). Therefore, if you swap the ones behind the seats with upgrades, you won't get much, if anything, out of them because they are not sent signal the same way as in the other applications you listed. Swapping them out will not overcome the fact that the amp doesn't really use them. Does that make sense?

Thanks for the clarification. I did hookup a frequency generator to study this further. IIRC the 8" behind the seat are noticeable until about 60Hz at which point it seems the in dash 6" and footwell 6" join in.

As far as how the processing differentiates from other BMW's I will have to see.

Regardless. I have the SWS subwoofers and would like to put them in and see how it changes.

Does anyone know how to get to the subwoofers behind the seats?

[dblaron30i]

Ok I'm going to list off first that I have been a sound engineer system designer for over 20years in the entertainment industry. I think the question you are really asking comes down to processing. If you have the the idrive system the rear subs work differently due to it being in a special surround mode that BMW uses. If you have just the the system with the subs and no idrive it works differently. It isn't really a surround mode and the rear subs have more output believe it or not. But yes. If you put in the SWS subs you will get more output. Yet more on the non idrive system. The reason for this is lower impedance and higher quality parts. It's kinda like this. You all baught your BMW's because of the performance and quality. But you weren't going to buy a Chrysler Sebring even though they are both convertible with roughly the same size motor. So I'm just going to use that. I'm not going to go into the technical as to why it always is better to upgrade your speakers from OEM. As for taking out the subs. I would think that the cover is succured to with clips. If it wasn't it would make a lot of noise. Try one of those plastic prying tools they make for trim.

[NoQuarter]

z4 dash forum dot com/forum/viewtopic.php?f=46&t=75861

[bmw>benz]

Originally Posted by dblaron30i

Ok I'm going to list off first that I have been a sound engineer system designer for over 20years in the entertainment industry. I think the question you are really asking comes down to processing. If you have the the idrive system the rear subs work differently due to it being in a special surround mode that BMW uses. If you have just the the system with the subs and no idrive it works differently. It isn't really a surround mode and the rear subs have more output believe it or not. But yes. If you put in the SWS subs you will get more output. Yet more on the non idrive system. The reason for this is lower impedance and higher quality parts. It's kinda like this. You all baught your BMW's because of the performance and quality. But you weren't going to buy a Chrysler Sebring even though they are both convertible with roughly the same size motor. So I'm just going to use that. I'm not going to go into the technical as to why it always is better to upgrade your speakers from OEM. As for taking out the subs. I would think that the cover is succured to with clips. If it wasn't it would make a lot of noise. Try one of those plastic prying tools they make for trim.

Thanks for the info. I wasn't aware of different processing between iDrive/non-iDrive!

[bmw>benz]

Originally Posted by NoQuarter

z4 dash forum dot com/forum/viewtopic.php?f=46&t=75861

YOU'RE MY HERO

[PennBruce]

+1

Bruce

Originally Posted by NoQuarter

z4 dash forum dot com/forum/viewtopic.php?f=46&t=75861

[fmorelli]

Originally Posted by bmw>benz

3db gain does not necessarily mean the amp is working harder.

I didn't intend my post to be read that way. It's the other way around - a 3db increase in speaker efficiency means the amp does half the work to produce the same sound output.

In other words, it's like keeping the same speakers and doubling amplifier power (the other way to think about it).

Filippo

[dblaron30i]

Originally Posted by fmorelli

I didn't intend my post to be read that way. It's the other way around - a 3db increase in speaker efficiency means the amp does half the work to produce the same sound output.

In other words, it's like keeping the same speakers and doubling amplifier power (the other way to think about it).

Filippo

Ok so everyone is kinda right. This is how it breaks down. So if you are runing better speakers your amp can be turned up more. Yet then you run into the part called limiting the amp. At this point you will get distortion but your speakers can still handle the power. The only thing is it will be a little fuzzy in sound quality. The only way you would push the amp to hard is if you purchased speakers with a lower impedance like 1ohm which would burn the amp up because it's drawing to much power caused by less resistance. So as long as you stick with the same ohm speaker with a higher wattage you are fine. That's the technical answer.

[distinctperson]

Just to share my experience with E89s speakers. Having owned one with Basic, and the last two with Premium, they all rattle and distort notes at reasonably higher volumes (my benchmark for measuring this was listening to Intro by The XX -- excellent at accentuating those demanding notes.) With my 2nd E89 with Premium Audio, I went to a reputable auto audio store in the city and was told that I pretty much had to upgrade the amp as well as the speakers to stop experiencing the rattling and distortion at higher volumes. He was surprised, however, to find that E89s came with a 3 way component speakers btw.... he thought it was an overkill for such a tiny cabin (he shared than even the Ferrari 458 he worked on earlier had a 2 way front component system, although I believe that's irrelevant since the notes come from the engine if that's your vehicle

Adding an 8 channel JBL amp as well as upgrading the front 3 way components (6 speakers in total) plus installation yielded a whopping $2700. I also had him add sound deadening which was very effective at reducing outside noise. After the speakers break-in period of 48 hours of playtime, fidelity improved a bit, but, more importantly, rattling and distortion disappeared completely at higher volumes.

[dblaron30i]

Originally Posted by distinctperson

Just to share my experience with E89s speakers. Having owned one with Basic, and the last two with Premium, they all rattle and distort notes at reasonably higher volumes (my benchmark for measuring this was listening to Intro by The XX -- excellent at accentuating those demanding notes.) With my 2nd E89 with Premium Audio, I went to a reputable auto audio store in the city and was told that I pretty much had to upgrade the amp as well as the speakers to stop experiencing the rattling and distortion at higher volumes. He was surprised, however, to find that E89s came with a 3 way component speakers btw.... he thought it was an overkill for such a tiny cabin (he shared than even the Ferrari 458 he worked on earlier had a 2 way front component system, although I believe that's irrelevant since the notes come from the engine if that's your vehicle

Adding an 8 channel JBL amp as well as upgrading the front 3 way components (6 speakers in total) plus installation yielded a whopping $2700. I also had him add sound deadening which was very effective at reducing outside noise. After the speakers break-in period of 48 hours of playtime, fidelity improved a bit, but, more importantly, rattling and distortion disappeared completely at higher volumes.

You are exactly right. That is the proper way to do things. Yet you got it at a cost which unlike you or I most are not willing to pay. As for the distortion, yes you would get rid of it by upgrading your amp. Yet the rattling has nothing to do with the components. It's all in the sound dampening which you did. I would love to see how they placed the amp in your car. If it still looks factory or if they had to relocate it. I really don't like a lot of shops because they cut corners. They tend to attach wires the easiest and wrong way causing the system to cut in and out after several years.

[davis449]

I think the factory Premium sound system's components are just fine. I really see no need to replace them and spend insane amounts of money re-doing the whole system. My biggest problem with it is that, unless you use surround mode (which I don't because it sounds like shit), you really only use 6 of the speakers available (the front 3 ways). Simply swapping out the rear subs for better 8's (or retrofit 10's if you want to), and amplifying them separately or doing what I did and throwing a 10" in the trunk instead of replacing the stock woofers gets you a more than adequate sound system for top up and down audio. I've blasted it for 3 hours, top down, from Houston to SA playing a wide variety of music and never noticed distortion.

[dblaron30i]

Originally Posted by davis449

I think the factory Premium sound system's components are just fine. I really see no need to replace them and spend insane amounts of money re-doing the whole system. My biggest problem with it is that, unless you use surround mode (which I don't because it sounds like shit), you really only use 6 of the speakers available (the front 3 ways). Simply swapping out the rear subs for better 8's (or retrofit 10's if you want to), and amplifying them separately or doing what I did and throwing a 10" in the trunk instead of replacing the stock woofers gets you a more than adequate sound system for top up and down audio. I've blasted it for 3 hours, top down, from Houston to SA playing a wide variety of music and never noticed distortion.

That's cool. But because of the minimal space the car has a lot of people want to keep the factory look and what little trunk space the car does have. Another thing is sound is very subjective. Each person hears differently and if your system works for you that's great. Yet for me I am a professional sound engineer/designer. My ears have been trained for the last 20 years to hear what others don't. So for me a lot of the time a good sound system is important to me because I hear the smallest imperfections. That's all. Actually it's kinda a curse because a lot of the time I can't enjoy going to a concert or show without dissecting the music and sound system. I always want to improve it. So maybe it's the same with the Z4 with keeping the same factory look and feel.

[davis449]

Originally Posted by dblaron30i

That's cool. But because of the minimal space the car has a lot of people want to keep the factory look and what little trunk space the car does have. Another thing is sound is very subjective. Each person hears differently and if your system works for you that's great. Yet for me I am a professional sound engineer/designer. My ears have been trained for the last 20 years to hear what others don't. So for me a lot of the time a good sound system is important to me because I hear the smallest imperfections. That's all. Actually it's kinda a curse because a lot of the time I can't enjoy going to a concert or show without dissecting the music and sound system. I always want to improve it. So maybe it's the same with the Z4 with keeping the same factory look and feel.

That's why I proposed the best way to do it was to swap the 8's in the rear. You can use drop ins and amplify them. Keep the stock look and feel. I have a 500 watt amp installed where the OP is trying to get access to...right next to the stock amplifier. Out of sight completely. I didn't do it this way because I want to be able to easily remove the sub when my lease is up. The way the amp is mounted it will come out very easily.

I fully agree sound is subjective. I know you've been trained to hear things that no one hears. I was born that way, I shit you not. I know the curse. I actually don't like going to concerts for the exact same reasons. I'm never happy with the sound in any venue. I find fault with the stock speakers as well but, in my case, the curse can be overridden by cost in some cases. I envy you for your training. I would love to know half of what you probably do about the technicals. At the end of the day, it's "good enough" that I don't feel it necessary to tear it apart, modify the housings to accommodate better components, re-run wiring, and adding yet another amp. Especially not in a convertible and especially not in a leased car. From my POV, there's just not enough audible distortion at the volumes I listen to it at.

And screw you very much, now I'm thinking about swapping the rear 8's and selling my 10, you jerk.

[dblaron30i]

Originally Posted by davis449

That's why I proposed the best way to do it was to swap the 8's in the rear. You can use drop ins and amplify them. Keep the stock look and feel. I have a 500 watt amp installed where the OP is trying to get access to...right next to the stock amplifier. Out of sight completely. I didn't do it this way because I want to be able to easily remove the sub when my lease is up. The way the amp is mounted it will come out very easily.

I fully agree sound is subjective. I know you've been trained to hear things that no one hears. I was born that way, I shit you not. I know the curse. I actually don't like going to concerts for the exact same reasons. I'm never happy with the sound in any venue. I find fault with the stock speakers as well but, in my case, the curse can be overridden by cost in some cases. I envy you for your training. I would love to know half of what you probably do about the technicals. At the end of the day, it's "good enough" that I don't feel it necessary to tear it apart, modify the housings to accommodate better components, re-run wiring, and adding yet another amp. Especially not in a convertible and especially not in a leased car. From my POV, there's just not enough audible distortion at the volumes I listen to it at.

And screw you very much, now I'm thinking about swapping the rear 8's and selling my 10, you jerk.

Sorry dude. That wasn't my intent. Most people are happy with what they have and the style of music they listen to. But I would love to see a pic of how the amp was mounted if you have any. 500watts is more than enough for a car this size. The only thing I would suggest to people is replace the mains with the focus brand speakers. The sound quality you get out of them is better than any high end factory speaker. Including boss or Harman. Those speakers are actually crap mass produced and marketed to the extreme. The are all hype. As for the subs. I like JL Audio at 1ohm. But that requires a new amp. But post your pics. Would love seeing the amp setup.

[davis449]

Originally Posted by dblaron30i

Sorry dude. That wasn't my intent. Most people are happy with what they have and the style of music they listen to. But I would love to see a pic of how the amp was mounted if you have any. 500watts is more than enough for a car this size. The only thing I would suggest to people is replace the mains with the focus brand speakers. The sound quality you get out of them is better than any high end factory speaker. Including boss or Harman. Those speakers are actually crap mass produced and marketed to the extreme. The are all hype. As for the subs. I like JL Audio at 1ohm. But that requires a new amp. But post your pics. Would love seeing the amp setup.

Well, you already put the thought in my head, it's too late for sorry now!

I agree most people are happy. Obviously, I wasn't happy enough hence the sub. So the stock amp is 875W and I use the 500W for the JL sub (I, too, am a JL fan). I bought and had them use Technic's harness to grab low signal and remote from the stock amp. No cutting, fully plug and play. As I stated before, it really does suck that I'm really only using 6 speakers, from an available vs. use standpoint. All that wattage wasted on 14 speakers for a 2-seater roadster so it can have surround sound that sounds like crap.

X2 on the Focals (or a number of others). I'm aware they're all mass produced off-the-shelf stuff. I think surround mode really brings out the flaws in them. Switch it back, though, and it's much different. Not spectacular, but more than tolerable to my ears.

Let me get familiar with the guide posted and I will see if I can get in there to take some pics (it was done professionally by a trusted audio shop here as I have gotten lazier as I've gotten older). If the OP takes pics and beats me to it, I'll point out the location using his pics.