[kaigoss69]

Originally Posted by sahyoun

So many incorrect statements, the stock amp does have enough power to drive the 2 ohm xi's if you're running top hifi/l7. In terms of the SWS sucking at mid range, they blow the stock ones out of the water. Dropping from a 4ohm to a 2ohm increased the the entire range on all the cars I ran it on.

In terms of the Earthquakes playing down to 40 hz. The range is set by the stock amp so the stock subs are playing down there too. The frequency range of the sub should be the same, its the resonance frequency that changes when you swap to sws which might sound like they are playing at a different frequency range to the untrained ear. In terms of the phase, you dont adjust the underseats to be in phase with the trunk sub, you adjust the already-aftermarket trunk sub's phase. Setting a range of 80-200hz on the underseats would sound terrible. Yeah a trunk sub will take care of the rest but the OEM underseat enclosure does a really good job of evenly distributing the bass and actually sounds like a more natural setup.

You must have low standards, sir, if you think Earthquakes produce good "midrange". It is actually mid-bass we are talking about, and they are terrible at it. And when I say terrible, I mean they freaking suck ass, as in the worst I may have heard. That's by design however, because most drivers that are designed to reproduce low frequencies do not do very well in other frequency ranges, hence the need for more than one speaker pair in a system. Everything is relative, though, and your standards may not be the same as mine (I know they're not), nor may they be the same as those of most other people. I have been in car audio for over 30 years, and I think I have some perspective now to be able to tell what sucks and what does not. If you think they sound great, please do yourself a favor and find someone with a good car audio system with good mid-bass and then tell me the cars you equipped with Earthquakes still sound good to you.

And please, don't come on here telling people to run 2 ohm speakers on factory amps that were designed to run 4 ohm (and it is OK to do so because the voice coil is "higher"). Just because your amp has not fried yet does not mean somebody else's won't. Intentionally overloading expensive factory amplifiers like that is just plain ignorant and the smart thing to do is use aftermarket amplification, and separation of frequencies.

Furthermore, you state "setting a range of 80-200 Hz on the underseats would sound terrible". Were are you coming from to make such a statement? - Just before I sold my 335i I had 10" mid woofers under the seats, driven 250W each. They were playing 55 - 110Hz, an even tighter range. If you had heard that set-up, you would have shut up real fast and admitted that you have absolutely no clue as to what you are talking about.

Finally, you state in another post that "the impedance rating on a sub is done when the cone is at a neutral resting position" and you mumble about voice coil height and "resistance". That is just plain wrong on so many levels and I'm not getting into a technical discussion about loudspeaker design. Google is your friend here, and your teacher.

[bmw>benz]

Originally Posted by kaigoss69

You must have low standards, sir, if you think Earthquakes produce good "midrange". It is actually mid-bass we are talking about, and they are terrible at it. And when I say terrible, I mean they freaking suck ass, as in the worst I may have heard. That's by design however, because most drivers that are designed to reproduce low frequencies do not do very well in other frequency ranges, hence the need for more than one speaker pair in a system. Everything is relative, though, and your standards may not be the same as mine (I know they're not), nor may they be the same as those of most other people. I have been in car audio for over 30 years, and I think I have some perspective now to be able to tell what sucks and what does not. If you think they sound great, please do yourself a favor and find someone with a good car audio system with good mid-bass and then tell me the cars you equipped with Earthquakes still sound good to you.

And please, don't come on here telling people to run 2 ohm speakers on factory amps that were designed to run 4 ohm (and it is OK to do so because the voice coil is "higher"). Just because your amp has not fried yet does not mean somebody else's won't. Intentionally overloading expensive factory amplifiers like that is just plain ignorant and the smart thing to do is use aftermarket amplification, and separation of frequencies.

Furthermore, you state "setting a range of 80-200 Hz on the underseats would sound terrible". Were are you coming from to make such a statement? - Just before I sold my 335i I had 10" mid woofers under the seats, driven 250W each. They were playing 55 - 110Hz, an even tighter range. If you had heard that set-up, you would have shut up real fast and admitted that you have absolutely no clue as to what you are talking about.

Finally, you state in another post that "the impedance rating on a sub is done when the cone is at a neutral resting position" and you mumble about voice coil height and "resistance". That is just plain wrong on so many levels and I'm not getting into a technical discussion about loudspeaker design. Google is your friend here, and your teacher.

Actually what Sahyoun says is correct.

1. Typically Impedance is measured in neutral position. That being said a 4 ohm sub will not measure as a 4 ohm sub. (3.5ohm) and a 2 ohm typically measures 1.5ohm. Common knowledge for anyone in this industry for 30 years. IMPEDANCE VARIES as a subwoofer plays.

2. The impedance DOES go down when a coil leaves its magnetic gap. The stock sub certainly has a shorter coil meaning that it is possible for it to leave the gap and have impedance fluctuations. What i think Sahyoun was trying to say is that the SWS appears to have a much longer coil and that even though it is 2 ohm it is more consistent than the 4ohm.

3. It is VERY common for an amp IC to be 2-ohm stable. And i have seen it mentioned that the stock amps are 2-ohm stable. That being said, this is still he said she said. I will see if I can find further confirmation.

4. Of course your 2 10" with dedicated amp sound better. You cant defy the laws of physics. That is a setup that easily costs double the money of two drop in SWS.

5. For someone with 30 years experience, your language is very vague. "The Earthquakes are terrible at midrange". How so? SQ? SPL? This is an industry filled with opinion so you should be specific. Moreover, sound is the most subjective thing to discuss so it is futile.

For what they are worth, the SWS are a GREAT bargain and a noticeable improvement over stock. I have ran the SWS in about 4 different e9x cars without failure. The only failures I saw were online where some people blew the dustcap off. I have yet to see someone kill an amp from using the SWS.

[kaigoss69]

^^^

1. Impedance is not DC resistance. Look it up.

2. Voice coils typically operate only within the magnetic gap. If they leave the gap, the speaker is overdriven and distortion occurs. Impedance is frequency dependent, not position of coil.

3. Even if the ICs can handle the load, the power supply may not. In any case, the amp will run hotter and will fail sooner.

4. The laws of physics apply to my claim that the Earthquakes cannot reproduce all frequencies well. My 10" woofers were optimized, by speaker design and installation position, to reproduce a tight frequency band. The Earthquakes cannot accurately reproduce frequencies above ~80Hz by design.

5. That was not my statement. I said they sucked at "mid-bass". This is roughly 100-200Hz, in this case. Male voices fall into this range, for example. Listen to Johnny Cash with the earthquakes, and then on a system with proper mid bass. You will not believe your ears! Also kick-drums, or the snappy bass from a bass guitar, will just underwhelm when using the Earthquakes. Again, try to compare, and gain some perspective.

[david in germany]

Eq SWS woofers were the worst woofers I have ever used( and killed on 75w rms at 35-100hz).
I support/agree with everything that kaigoss69 stated above in his posts.

[N54B30A]

Originally Posted by david in germany

Eq SWS woofers were the worst woofers I have ever used( and killed on 75w rms at 35-100hz).
I support/agree with everything that kaigoss69 stated above in his posts.

I had my stock subs fail on the stock amp, i've never had an sws fail on me but subs from any manufacturer can fail based on abusive use or in some cases a defect but having run 6 different SWS's on 3 different cars all with top hifi and not a single sub or amp failed. If you guys only knew what the SWS internals look like compared to every other shallow woofer you'd realize. The coil alone is wound more with a much larger travel capability. The main attracting point of the SWS is the patented mounting position of the spider, having it in line with the motor allows for the most excursion per unit mounting depth. All the shallow subs look like rip offs of each other except the SWS when it comes to internals.

[N54B30A]

Originally Posted by kaigoss69

^^^

1. Impedance is not DC resistance. Look it up.

2. Voice coils typically operate only within the magnetic gap. If they leave the gap, the speaker is overdriven and distortion occurs. Impedance is frequency dependent, not position of coil.

3. Even if the ICs can handle the load, the power supply may not. In any case, the amp will run hotter and will fail sooner.

4. The laws of physics apply to my claim that the Earthquakes cannot reproduce all frequencies well. My 10" woofers were optimized, by speaker design and installation position, to reproduce a tight frequency band. The Earthquakes cannot accurately reproduce frequencies above ~80Hz by design.

5. That was not my statement. I said they sucked at "mid-bass". This is roughly 100-200Hz, in this case. Male voices fall into this range, for example. Listen to Johnny Cash with the earthquakes, and then on a system with proper mid bass. You will not believe your ears! Also kick-drums, or the snappy bass from a bass guitar, will just underwhelm when using the Earthquakes. Again, try to compare, and gain some perspective.

You can sit here speculating and theorizing all you want about whether or not a 2ohm will cause the amp to fail, but the fact is theres several people using a 2ohm just fine myself included. So theory is meaningless in the face or real world testing. Find me a case or two where a 2ohm woofer caused the L7 amp to fail prematurely, because I cant find any aside from a few failing on stock subs.

With regards to the power supply, it can handle it. These amps are rated for 600W and you really arent passing 400W total by much on the stock subs. What most people dont know is bmw has been using this same amp with different part numbers on multiple models that have varying impedance on not just the sub but the entire system. BMW just tunes the crossovers. I guess someone will just have to contact LEAR to get a straight answer.

[kaigoss69]

Well for what it's worth, I googled for "Logic 7 amp internals" and came across information that leads me to believe the IC used is a "TDA1562". All the data sheets I have found for that IC reference a 4 ohm minimum load, and a maximum output of 70W (at 10% THD).

http://www.mouser.com/ds/2/302/TDA15..._SD-355606.pdf

[N54B30A]

Originally Posted by kaigoss69

Well for what it's worth, I googled for "Logic 7 amp internals" and came across information that leads me to believe the IC used is a "TDA1562". All the data sheets I have found for that IC reference a 4 ohm minimum load, and a maximum output of 70W (at 10% THD).

http://www.mouser.com/ds/2/302/TDA15..._SD-355606.pdf

I saw that IC was listed for the older L7 amps but not sure if its still in use. I read that several times and nowhere does it say not to go below a 4 ohm load, it just states 70W/4 Ohms, typically the IC datasheet will show an absolute minimum load, this one did not. In any case, this is the real world. Find me one case of an L7 failing due to a 2 ohm load on E8x,E9x, E6x, or any other ones using that amp.

[david in germany]

Originally Posted by N54B30A

I had my stock subs fail on the stock amp, i've never had an sws fail on me but subs from any manufacturer can fail based on abusive use or in some cases a defect but having run 6 different SWS's on 3 different cars all with top hifi and not a single sub or amp failed. If you guys only knew what the SWS internals look like compared to every other shallow woofer you'd realize. The coil alone is wound more with a much larger travel capability. The main attracting point of the SWS is the patented mounting position of the spider, having it in line with the motor allows for the most excursion per unit mounting depth. All the shallow subs look like rip offs of each other except the SWS when it comes to internals.

I have had two SWS fail on me. I have seen the internals and although they do have a cool design are in no way better than all the other shallow woofers. Ever seen the internals of JL Audio shallow woofers? You had luck with multiple SWS, good for you, I had better luck with upgrading to Logic 7 woofers and now Gladen audio woofers.

[Bent_remy]

This tread is too important to die. Thank you N54B30A. Gonna try this.

[Asonchadwick]

Originally Posted by Bent_remy

This tread is too important to die. Thank you N54B30A. Gonna try this.

Agreed. I am installing 2 ohms woofers, not sws, and I can find no where listed the factory woofers impedance. I have a 2010 335d logic 7

[ctuna]

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

2 x70 W (4 Ω) Bass
6x40 W 40 (2 Ω)

from the second link.
Also from the first sentence of this entire thread.

[Black_e90]

So...... Anyone blow up a L7 amp from installing 2ohm subs yet? I want to get the 2 ohms but this thread has been 50/50 on either 2 ohm or 4 ohm 😂. The talk about the 2 ohm sounding better is a nice plus🤷🏻*♂️

[Black_e90]

Sorry to revive an old thread again but I ended up going with the 2ohm one and made a how to on it. Hope it helps some people in making their decision!

[Maxmil982]

Originally Posted by kaigoss69

You must have low standards, sir, if you think Earthquakes produce good "midrange". It is actually mid-bass we are talking about, and they are terrible at it. And when I say terrible, I mean they freaking suck ass, as in the worst I may have heard. That's by design however, because most drivers that are designed to reproduce low frequencies do not do very well in other frequency ranges, hence the need for more than one speaker pair in a system. Everything is relative, though, and your standards may not be the same as mine (I know they're not), nor may they be the same as those of most other people. I have been in car audio for over 30 years, and I think I have some perspective now to be able to tell what sucks and what does not. If you think they sound great, please do yourself a favor and find someone with a good car audio system with good mid-bass and then tell me the cars you equipped with Earthquakes still sound good to you.

And please, don't come on here telling people to run 2 ohm speakers on factory amps that were designed to run 4 ohm (and it is OK to do so because the voice coil is "higher"). Just because your amp has not fried yet does not mean somebody else's won't. Intentionally overloading expensive factory amplifiers like that is just plain ignorant and the smart thing to do is use aftermarket amplification, and separation of frequencies.

Furthermore, you state "setting a range of 80-200 Hz on the underseats would sound terrible". Were are you coming from to make such a statement? - Just before I sold my 335i I had 10" mid woofers under the seats, driven 250W each. They were playing 55 - 110Hz, an even tighter range. If you had heard that set-up, you would have shut up real fast and admitted that you have absolutely no clue as to what you are talking about.

Finally, you state in another post that "the impedance rating on a sub is done when the cone is at a neutral resting position" and you mumble about voice coil height and "resistance". That is just plain wrong on so many levels and I'm not getting into a technical discussion about loudspeaker design. Google is your friend here, and your teacher.

What 10" fit under the seat?

[kaigoss69]

Originally Posted by Maxmil982

What 10" fit under the seat?

None you can buy today AFAIK. They were old school Morels, and I had to totally destroy the plastic tubs (enclosures), as well as vent to the bottom (outside air).

[N54B30A]

For anyone wondering, Earthquake Sound just released some very in-depth video on the SWS in BMWs.

You can buy them directly from Earthquake Sound: https://earthquakesoundshop.com/?s=s...t_type=product

For the record I've run these in 2 e90s, 3 e92s, my f87, my F15 and have NEVER had the subs or amp fail even after dropping to a 2ohm load.

[Cavi Mike]

I’m so glad he made that video because nowhere does it say that those drivers use a neo magnet. Neo magnets are paramount to a high efficiency driver. I don’t know why Earthquake doesn’t advertise this anywhere. I also really like how passionate this guy is - and he well should be - because his design really is the best out there right now for shallow mount subs.

Originally Posted by N54B30A

For anyone wondering, Earthquake Sound just released some very in-depth video on the SWS in BMWs.

You can buy them directly from Earthquake Sound: https://earthquakesoundshop.com/?s=s...t_type=product

For the record I've run these in 2 e90s, 3 e92s, my f87, my F15 and have NEVER had the subs or amp fail even after dropping to a 2ohm load.

[Onizukachan]

Reading some people with wierd ideas of what underseat xover points (55-200 is idiocy) should be and apparently trying to use these as mid basses. I ran my 8xi down to 24hz with a 30db slope on the match up7bmw in my f31. As I recall I was playing them only up to about 85-90 as they start localizing at about 86 ish,, and had them overlapped with the factory 4” which played down to 80 but had no authority until around 95ish… thus the xover overlap to use the 4 for localization and the SWS to help fill in volume level

SWS are subwoofers not mid basses. Mid bass is 80 and up.

Read the specs, and compare the actual numbers. Best underseats out there and clean as hell , completely unlocalizable, when used and tuned appropriately.