How to Improve OE Sub Bass Quality and Eliminate Vibrations

[afkdoorbell]

Do not overpack the bass cavity with wading...You'll destroy lower bass response..

As described in my writeup only the inner walls of the cavity should be covered...I know some people have had problems in the past placing the thin sheet wadding against the walls...And although less than ideal, you can also pull the wadding sheets apart to fluff them up and very loosely fill the cavity...Just do not compress the wadding or you'll greatly reduce low end bass response...

Hi,
So the key is to fill the cavity with the wadding but not pack it to max?
I filled mine up but haven't filled to the point where I can't stuff any more.

I just didn't know how to know when is the right amount?
Mine isnt' the roll up type, it's the polyfill
https://amzn.to/45NwpBW

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[swrdply400mrelay]

Hi,
So the key is to fill the cavity with the wadding but not pack it to max?
I filled mine up but haven't filled to the point where I can't stuff any more.

I just didn't know how to know when is the right amount?
Mine isnt' the roll up type, it's the polyfill
https://amzn.to/45NwpBW

Not sure how to quantify it, but I initially packed it tight and tested the bass, it was horrible. Took some out and improved a lot. I’d test the sound to see if you can tell there’s an improvement.

 

[afkdoorbell]

Not sure how to quantify it, but I initially packed it tight and tested the bass, it was horrible. Took some out and improved a lot. I’d test the sound to see if you can tell there’s an improvement.

Yeah I'll play with how much. From what I'm seeing and reading, maybe have enough room for air flow and room inside.

 

[calmeda1]

Hi,
So the key is to fill the cavity with the wadding but not pack it to max?
I filled mine up but haven't filled to the point where I can't stuff any more.

I just didn't know how to know when is the right amount?
Mine isnt' the roll up type, it's the polyfill
https://amzn.to/45NwpBW

I originally over filled it and it killed the bass. I took it all out and re-filled it just enough to cover the inner walls. 10000% better. Just cover the walls and leave the center hollow

 

[afkdoorbell]

I originally over filled it and it killed the bass. I took it all out and re-filled it just enough to cover the inner walls. 10000% better. Just cover the walls and leave the center hollow

Yup, I took alot out and my god it sounds so good I wanna cry lol
My Supra actually sounds like it has subs instead of blown out 1920s speakers.

Yay!!

 

[Loco38SUP]

I originally over filled it and it killed the bass. I took it all out and re-filled it just enough to cover the inner walls. 10000% better. Just cover the walls and leave the center hollow

I did the same and took it all out. It sounded much better without it.

-RJM

 

[tadda]

If you go back to my very first post the intent was never to fill the entire volume of the cavity with batting...The sheet batting was to be used to simply line all the metal walls to soften the internal reflections effectively increasing the cavity volume...

That said, some people seem to struggle with unfolding the sheet batting to line the cavity walls and it ended up that they started overstuffing / packing the entire cavity with the batting which to no surprise degraded the bass response!

Side note: Can't believe it's been over 5 years since my original post!

 

[JerseyMKV3.0]

Did this and added some EarthQuake SWS 2ohm since I have a Mobridge amp crazy different now appreciate this post!

 

[chilly9797]

Hey all! So I did the fix sounds better ported. Though I feel like I am now getting feedback from a rear tweeter. Doubt it has anything to do with it as the sub seems to be fine. Is it coincidence or anyone have this issue? Did I blow a tweeter on a 6 month old car?

 

[mack73]

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.

 

[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?

 

[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?

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