How to Improve OE Sub Bass Quality and Eliminate Vibrations

[BMWAF]

I did the normal mods here but was unhappy with the low hit - just not quite enough for me. So I swapped out my speakers with the Earthquake SWS 4ohm versions. Plug and play (includes spacer ring and wiring adapter to plug into OEM harness). Low hits are WAY better than the stockers - I haven't listened to the Bavsound or Alpha speakers so I can't compare, but for those that want some more low hit without an aftermarket amp/sub box this is a great option at $240 https://www.amazon.com/dp/B002MRD4SE . Thinking of adding some low pass inline filters to cut out the high frequencies. But even like it is now its great.

What was installation like. DId you just go in through the top?

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[JerseyMKV3.0]

What was installation like. DId you just go in through the top?

No, you have to prop up that subwoofer panel as the subs aren’t circular they have that proprietary shape. All in all not to bad of an install once you pull the other panels off.

 

[JerseyMKV3.0]

I assume we have the same amp, the mobridge K2. https://mobridge.us/product/mobridge-most-amplifier-bmw-audi-mercedes/.

I thought our subs are 4ohm subs

Factory Subs are 4ohm, however the Mobridge amp is stable at 2ohms and outputs more power at 2ohms (150w) so that’s why I went with the 2ohm version. The 4ohm SWS are more for guys that stay with the factory amplifier to not tax the factory amp with such a low resistance

 

[mack73]

What was installation like. DId you just go in through the top?

As said above, you can't just go up through the carpet panel. I did it like in this video. Pulling all the plastic is the scariest part - and when you pull the panel with the 2 speakers below the seat belt, there are clips that go down behind the lower panel, not really explained in the video. You have to pull the top out and then up.

 

[tuskenraider]

So after reading the majority of this thread, as well as watching a couple videos of people doing these modifications, I came across a comment that said the subwoofer are in a sealed plastic enclosure. Which then means as he noted, that adding ports does absolutely nothing to change the bass response. I could see the foam eliminating some vibrations, but that has to be minimal at best I would think. Has anyone put their hand at the ports and felt air movement when at a high enough volume to expect to feel something?

 

[J29DB03]

So after reading the majority of this thread, as well as watching a couple videos of people doing these modifications, I came across a comment that said the subwoofer are in a sealed plastic enclosure. Which then means as he noted, that adding ports does absolutely nothing to change the bass response. I could see the foam eliminating some vibrations, but that has to be minimal at best I would think. Has anyone put their hand at the ports and felt air movement when at a high enough volume to expect to feel something?

Yes, there is air coming out of the ports.

 

[mack73]

The plastic enclosure has a giant hole in the bottom. It is not sealed by itself. There is a photo earlier in the thread showing the green gasket that seals the plastic enclosure to the metal of the car. The metal of the car has holes on top that lead into the big space where the batting is placed, and has holes on the sides that line up to where you drill the holes for the ports. Yes you can feel air moving at the ports

 

[tadda]

So after reading the majority of this thread, as well as watching a couple videos of people doing these modifications, I came across a comment that said the subwoofer are in a sealed plastic enclosure. Which then means as he noted, that adding ports does absolutely nothing to change the bass response. I could see the foam eliminating some vibrations, but that has to be minimal at best I would think. Has anyone put their hand at the ports and felt air movement when at a high enough volume to expect to feel something?

No, they are not sealed enclosures...There is a lot of misinformation in the videos I've seen posted! This has been discussed in great detail throughout this thread...And yes, you can definitely feel the air pressure exiting during deep bass hits.

This is the bottom of the woofers plastic enclosure...

Air vent paths exiting from the bottom of the plastic woofer housing (see arrows shown below).

 

[tuskenraider]

Well thanks everyone for the info! Clearly I missed or misunderstood some details/pics.......will get going this mod.

 

[Unc_j]

Thx @tadda did this today at made a big difference. It’s 8” subs so I wasn’t expecting much but it cleared the sound system a lot

 

[john99teg]

Have not been in this thread for a while, but I have another tip that makes the sound have more "powerful" bass even after the ported hack. It so simple. Adjust the position of the sound 3-4 adjustments to the rear and now I can feel the lower frequency even better. 3 seems to be the sweetspot but 4 if you like it loud. I also made adjustments to the equalizer but now I feel like its actually sounding decent.

 

[Unc_j]

Have not been in this thread for a while, but I have another tip that makes the sound have more "powerful" bass even after the ported hack. It so simple. Adjust the position of the sound 3-4 adjustments to the rear and now I can feel the lower frequency even better. 3 seems to be the sweetspot but 4 if you like it loud. I also made adjustments to the equalizer but now I feel like its actually sounding decent.

Thx I did this but set mine to 2

 

[geo.MKV]

Great write up - I just completed all of the steps. It does sound a lot better, however I am still getting some rattle whenever the bass hits hard. It's coming from the top sub cover/carpet enclosure because I can eliminate it if I reach back and pull/put pressure on it.

I'll probably take it apart to see if i can adjust or add anything else, and I might as well do the SWS speaker upgrade while I'm in there .

 

[charlesr]

The 1st post talks about Harmon Kardon subs, but I have the JBL system. Is the advice about porting the panel still valid?

And if I were to switch to the Ghost Bavsounds, will they need the same porting? #audionoob.

Are all these just referring to different drivers plugged into the rectangular case that I've seen photos of (e.g. referred to as "Woofer enclosure" further up this page).

 

[JerseyMKV3.0]

The 1st post talks about Harmon Kardon subs, but I have the JBL system. Is the advice about porting the panel still valid?

And if I were to switch to the Ghost Bavsounds, will they need the same porting? #audionoob.

Are all these just referring to different drivers plugged into the rectangular case that I've seen photos of (e.g. referred to as "Woofer enclosure" further up this page).

The JBL system is Harmon Kardon. So yes it’s Still valid. I would steer clear of the bavsound as it’s just Chinese crap that’s rebranded and they have a great marketing team. Go for Audison/Match etc for plug and play subs.

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