Review: Earthquake SWS-8xi (2-ohm) and Rockford Fosgate P300-2

[frankzlin79]

I just got back from my stereo shop (Custom Car Stereo), who did a marvelous and clean installation of two Earthquake SWS-8xi (2-ohm) subs and a Rockford Fosgate P300-2.

I wasn't present during the entire installation so I just have a few pictures of the installation process.

The Subs:











I purchased two SWS-8xi from Ebay for about $130 shipped, each. The SWS-8xi is the 2-ohm version. For those looking for the 4-ohm version, the model is SWS-8x. At the moment, the 2-ohm version is sold out online, but there are still 4-ohm available for sale on Ebay.

Because the Earthquake sub is slightly deeper than the factory sub, it was necessary to add a 1/4" spacer. Of course, doing so will create the sub rubbing on the carpet issue. However, I listened to my stereo with the carpet touching the sub, as seen below,



And listened to the stereo with the carpet completely out of the way, as seen below:



I honestly did not hear a difference between the two. Therefore, I was fine with knowing that the carpet would touch the sub on long excursions. I did not want to cut the carpet away, because that would leave about a quarter of the woofer exposed to dust. The factory sub grills are not circles that completely cover the woofer. I don't have a picture, but the grill only covers about 80% of the woofer and the carpet covers the remaining 20% of the woofer. Strange design.

The installer did not feel the need to weather strip or dynamat around the SWS subs. He felt that with the spacer and screws all bolted directly to the floor, there was no wiggle room, so rattling would be unlikely.

The Amp:

Rockford Fosgate P300-2





This is a great amp! I have had Alpine and JL- Audio in the past, and Rockford Fosgate seem to be up there in terms of build quality. Here is the specification sheet that each Rockford amp is supplied with. Note that in 2-ohm mode, I'm pushing 188 W RMS x 2, instead of the advertised 150 W RMS x 2. This means that Rockford under-rates its amp. My amp is running a total of 376 W RMS (at 2-ohm) and a total peak power of 1127 W (at 4-ohm)! Not bad for paying only $160 shipped from E-bay.



The Amp Wiring Kit:

http://www.rockfordfosgate.com/produ...n_US&p_status=

I bought a Rockford Fosgate RFK8x from Best Buy for $75 after tax. The reason that I chose Rockford branded amp wiring kit was because Rockford offers to extend the 1-yr warranty on their amps by an additional year, if you use Rockford Fosgate wiring kits. So, I have a 2-year warranty on my P300-2. This kit comes with everything you need (except the line-out-convertor) for the installation.

The Installation:

I initially thought that I would want the amp mounted inside the compartment where the mobility kit is stored. It will fit there nicely. However, the installer said that with the lid shut, I may have some over-heating issues on long drives and heavy listening. To play it safe, I took his recommendation to have the amp mounted upside down, underneath the rear deck. In the end, I'm glad I took his recommendation. The P300-2 gets very very hot, so it's good to have the amp out with sufficient breathing room.

Installation took a total of 5 hrs. My shop built a wooden amp rack and then wrapped it with carbon leather! The leather matches the interior of my car...a sweet surprise that they didn't tell me about! The amp was mounted upside down onto the rack. Inside the rack is a cubby-hole where all the wiring to the amp, including the line-out-converter (purchased from my shop), is stored. The wires were further wrapped with black tubing you can see extending out the left and right side of the amp. Very neat and clean, which is expected from my shop.

The installer ended up cutting the factory speaker harness on both driver and passenger side subs (didn't know he was going to do that, but he assured me that he can reverse it later if I want to revert to stock). He then got the inputs from said cut factory wires and fed them into the line-out-convertor. From the line-out-convertor, he ran the RCA cable (comes with the RFK8x kit) going to the Rockford. For the Earthquake subs, he used new 16 gauge speaker wire (comes wit the RFK8x kit) to run directly to the Rockford amp. The speaker wire from the sub to the amp was run along the side edges of the plastic trim just above the M3 logo along the door sills and along the cushions on the sides of the rear seat. The rear seats had to be removed in order to take the rear side panels off. Therefore, there was no splicing of wires near the factory amp. I don't think the installer even removed the trim piece that covers the factory amp.





Who said that you have to sacrifice trunk space to have good sound?


The Sound:

Wow, what a difference. I have the gain and the Punch EQ on the amp set just slightly above minimum, the stock EQ is in the familiar W pattern, and treble/bass settings are at default.

I listen to a mix of dance, trance, hip-hop, rock, and pop. The subs are definitely noticeable improvement over stock. They do not hit as low or hard as my JL 12w0v2 I had in my other car, but that is expected since the Earthquake subs are housed in a very small enclosure space. I can now hear low notes that the Enhanced Premium Sound could not reproduce. A good example that comes to mind is TLC - No Scrubs. There is a very low note that is repeated in the song that the stock system, my laptop, and even my Klipsch Promedia 2.1 computer speakers have trouble producing. But the Earthquakes have no problem hitting this low note. The force of the bass is strong. On certain songs, it will rattle your chest and your feet (if touching the floor). Surprisingly, you do not feel the bass rumbling your butt (that's a good thing).

Overall, I am very happy with my purchases and recommend this setup (or a similar one) for those interested in adding more bass to their system. I spent about $525 in parts for a much improved sound.

[kaigoss69]

nice write-up and install! Regarding the carpet, I ended up cutting off the padding underneath, which was quite thick and made contact with the surround, and afterwards there was enough of a gap to be able to enjoy "touchless" bass.

[frankzlin79]

I don't think I'm going to remove the white padding underneath the carpet. Instead, I'm just going to unbolt the seat, unscrew the grill, pull the carpet from out underneath, re-attach the grills, and lat the carpet on top of the grill. This will guarantee that the carpet does not touch the woofer. It will look like crap, but it's underneath the seat and nobody will see it. The carpet should be sufficient to keep dust from touching the woofer.

[tinpot]

Thank you for the detailed write up!

I also have premium sound but I'm not enthused with the bass and would like to update my sound system. I mostly listen to House and Trance, but the bass just doesn't cut it. Since you're in the Houston area (I'm in the Galleria area) would it be possible to listen to your setup? If yes, could you PM me?

Cheers and congratulations on the new setup!

[Swancoat]

Nice, they actually bolted your amp down. More than they did for my when I had them install a stereo in my Porsche.

[frankzlin79]

I've had installed two radar detectors and two sound systems by Custom Car Stereo. They are a high-class shop. Their customers are usually drivers of high end cars. Today, they had a 2009 Mercedes SL65 AMG (the V12, biturbo) in the shop getting some performance seats installed.

Swancoat: I'm surprised that they did not bolt down your amp...that's pretty basic for any amp installation.

[Swancoat]

Well, they bolted them down after I came back a few days later. They were literally just banging around in the front trunk. No cleaned up wires, no nothing.

Not that the whole install was junk - they did some nice stuff, but overall, they charged huge $$$, missed every deadline, delivered the car half-done, and some components were utter crap.

They build me a sub-box for the trunk. Looks like they had their brother's kid do it. Pic is attached below. However, since my car was done, they've posted a pic on their website of a similar box they did for another Cayman that is far nicer than mine. Same thing with the trim for the new head unit up front. Mine is crap - and now they are showing pics on their site of a much nicer job than they did for me.

Back to the amps... they built a false floor in the front trunk, and put the amps underneath. The support for the false floor? It was the amps. Basically, a carpet covered board that rested on the amps, so if you actually put anything on it, it just pressed on the amplifiers.

I'm glad it worked out for you. I'd never go back.

Here's a pic of my sub box built by their 'top shelf fabrication shop'. (Note, this sub box was not initially attached when they delivered the car either. I took one corner, and it was banging around the rear trunk, tethered by the speaker wire).

[frankzlin79]

Swancoat: Hmmm...surprising that you had such a bad experience. Sorry to hear.

On another note, what should the cross-over frequency be set on my amp for the Earthquake subs? I'm currently set at 60 Hz. But I think that I should set it higher, maybe somewhere between 100-125Hz, to let the Earthquakes play more mid-bass?

[Tio///M]

Will this also work with non-Premium Sound systems and do you have Navigation/Tech Pk? I was just curious to know how yours was spec'd out and if I would to do something similar to this, would i have problems with the HiFi system...TIA

[frankzlin79]

Originally Posted by Tio///M

Will this also work with non-Premium Sound systems and do you have Navigation/Tech Pk? I was just curious to know how yours was spec'd out and if I would to do something similar to this, would i have problems with the HiFi system...TIA

I have the Enhanced Premium Sound with Navigation and Technology package. However, none of that will matter for you. It doesn't matter what type of OEM sound system you have or your options.

If you use an aftermarket amp to power your new subs, everything will be fine. The signal running from the stock amp to the stock subs is spliced into and diverted to your new amp. Be sure that you get this signal. Example, you do not want to get the signal going to any of the front speakers, because when the navigation voice prompt is activated, you do not want to send that signal to the amp.

[d_dot]

i need to find those subs!

[808MGuy]

Originally Posted by frankzlin79

I have the Enhanced Premium Sound with Navigation and Technology package. However, none of that will matter for you. It doesn't matter what type of OEM sound system you have or your options.

If you use an aftermarket amp to power your new subs, everything will be fine. The signal running from the stock amp to the stock subs is spliced into and diverted to your new amp. Be sure that you get this signal. Example, you do not want to get the signal going to any of the front speakers, because when the navigation voice prompt is activated, you do not want to send that signal to the amp.

This is not 100% correct. If you don't have enhanced premium sound, the preferred method to get the signal to an aftermarket amp is to tap the signal before the OEM amp. Its a much cleaner signal and you don't have to deal with any processing done within the OEM amp. The navigation voice prompt should be filtered out by the crossover on your aftermarket amp so that is not relevant in this application.

BTW, is that material they wrapped your amp mounting board with CF vinyl or CF leather? CF vinyl is relatively common and a lot of shops keep a small amount of it in their install bays. CF leather is not something cheap and it's something I wouldn't expect a shop to just throw in without charging someone for it. Either that, or they have a lot of "fat" built into their install prices.

[05SCM33]

Terrific write-up, thanks for sharing.

[M3OwnerHtown]

Great write-up! How much was the did CCS charge for labor and custom box/amp?

[Tio///M]

Okay tracking thanks a lot!! Very nice write up and thanks for the tech support.

Originally Posted by frankzlin79

I have the Enhanced Premium Sound with Navigation and Technology package. However, none of that will matter for you. It doesn't matter what type of OEM sound system you have or your options.

If you use an aftermarket amp to power your new subs, everything will be fine. The signal running from the stock amp to the stock subs is spliced into and diverted to your new amp. Be sure that you get this signal. Example, you do not want to get the signal going to any of the front speakers, because when the navigation voice prompt is activated, you do not want to send that signal to the amp.

[frankzlin79]

On second thought, I believe that I have carbon vinyl. It doesn't feel as thick as the carbon leather in the car. It feels a lot smoother, too.

[roller]

Originally Posted by frankzlin79

Swancoat: Hmmm...surprising that you had such a bad experience. Sorry to hear.

On another note, what should the cross-over frequency be set on my amp for the Earthquake subs? I'm currently set at 60 Hz. But I think that I should set it higher, maybe somewhere between 100-125Hz, to let the Earthquakes play more mid-bass?

You should definitely set the crossover to 100hz or higher, I think the SWS-8s start dropping off below 40hz. So if you set it at 60, you only really get the 40-60 range.

[frankzlin79]

How much higher should the cross-over be set at? Around 150 Hz?

[Technic]

Try 175Hz-200Hz...

[quality_sound]

Anyone know what the mids roll off at? 60Hz is WAY too low. I run my 8s to 250Hz with no issues but those are true midbasses not a sub. I think the 175-200Hz Technic suggested would be a good starting point.

[frankzlin79]

I set mine at 125 Hz. Anything higher doesn't sound good.

[d_dot]

just completed this diy this weekend with the help of Technic and it really is like night and day. i have the bass setting turned almost all the way down and they thump.