How to Improve OE Sub Bass Quality and Eliminate Vibrations

Reppunkamui

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This is getting me excited... tadda thanks for sharing I think I will give this a crack as well.

Kiwi Greg: Where did you get the stuff this side of the world. I am looking at jaycar for the speaker ports and damping material. Not sure where to pick up the foam or speaker mesh (might just try using speaker grille cloth instead).
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Kiwi Greg

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This is getting me excited... tadda thanks for sharing I think I will give this a crack as well.

Kiwi Greg: Where did you get the stuff this side of the world. I am looking at jaycar for the speaker ports and damping material. Not sure where to pick up the foam or speaker mesh (might just try using speaker grille cloth instead).
I got the damping from J-Car, https://www.jaycar.co.nz/650gsm-acrylic-speaker-dampening-material/p/AX3694

Ports from Element 14 https://nz.element14.com/penn-elcom...ube-2-diameter/dp/2808930?CMP=i-55c5-00001621

Foam from Mollies https://www.mollies.nz/product/1465008 should plenty of places that have 2" foam over there.

You should have the first two over there, from the links you can see the sizes & how much I had left, there is way too much damping

I used a pencil holder from the likes of K-Mart for the mesh, I just cut it up & it was black :)
 

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This idea is awesome and definitely a good first step in improving the quality of sound. Would you say this option would work well in conjunction with the other stock component replacement options outside of going full custom?
 
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tadda

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This idea is awesome and definitely a good first step in improving the quality of sound. Would you say this option would work well in conjunction with the other stock component replacement options outside of going full custom?
I would definitely consider doing this before installing a direct replacement subwoofer or your still going to be left with the same vibrational noise distortions and rattles...

I think what you'll find is that after doing this the OE Harmon Kardon speakers are actually quite decent...
 
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Reppunkamui

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Ok, committed to getting the items for this project now. Going to use speaker cloth rather than mesh for the holes, hopefully it will be ok with the air pressure.

Just a question on the port length (1 inch), is there a specific reason for the length? Would it matter if it is longer? I understand the audio inclined (not me) have calculations they do to determine optimal port size and lengths for speakers...
 
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Ok, committed to getting the items for this project now. Going to use speaker cloth rather than mesh for the holes, hopefully it will be ok with the air pressure.

Just a question on the port length (1 inch), is there a specific reason for the length? Would it matter if it is longer? I understand the audio inclined (not me) have calculations they do to determine optimal port size and lengths for speakers...
Not sure how well grill cloth will work as it's fairly dense..There is quite a bit of air pressure released during the low bass notes and you want to make it as least restrictive as possible...

With respect to port length, I wouldn't go any longer (and actually I would prefer a bit shorter) because you would most likely capture less exhaust air and increase rear plate vibrations due to the geometry differences between the 3 elongated ports and the 2" circular port (Side note: the cross sectional areas between the combined 3 elongated ports and the 2" circular port are similar)...Also keep in mind that the space between the rear cover plate and 3 elongated exhaust ports is less than 2"...Hope that all makes sense...

subwoofer 6 2 inch foam insulation with ports.jpg


subwoofer 7b ported rear panel.jpg
 
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Kiwi Greg

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Going to use speaker cloth rather than mesh for the holes, hopefully it will be ok with the air pressure.
I would definitely go with mesh rather than cloth, the amount of air moving through the port is quite surprising, its no wonder it rattled etc

I used something like this, because it was lying around home unused & cut it up https://www.kmart.co.nz/product/pen-cup---black/2668825

This one would be better & closer mesh to what I used, https://www.officeworks.com.au/shop...esh-pencil-cup-black-es47547bk#specifications
 

2k20HTownMKV

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I would definitely go with mesh rather than cloth, the amount of air moving through the port is quite surprising, its no wonder it rattled etc

I used something like this, because it was lying around home unused & cut it up https://www.kmart.co.nz/product/pen-cup---black/2668825

This one would be better & closer mesh to what I used, https://www.officeworks.com.au/shop...esh-pencil-cup-black-es47547bk#specifications
I actually have speaker cloth coming in as i really didn't want mesh as i was afraid it would rattle with it, so i will give this a try soon and report back to see if it causes any issues. i am just waiting on my foam to come in right now. All my other parts have arrived so i can start working on getting the 2inch hole cut for the port.
 
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I actually have speaker cloth coming in as i really didn't want mesh as i was afraid it would rattle with it, so i will give this a try soon and report back to see if it causes any issues. i am just waiting on my foam to come in right now. All my other parts have arrived so i can start working on getting the 2inch hole cut for the port.
I used 3m foam adhesive tape to secure mesh...The thickness of the 3m foam tape actually isolates the mesh from the wall and doesn't produce any rattles or vibration noises...I've never seen cloth applied to exhaust ports for very good reason, I think you may find that the cloth is going to be too dense as the velocity of air being released is quite impressive!...You might want to listen to some low bass "before and after" your cloth is applied to hear if there are any differences in noise..

Good luck with install!
 

2k20HTownMKV

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I used 3m foam adhesive tape to secure mesh...The thickness of the 3m foam tape actually isolates the mesh from the wall and doesn't produce any rattles or vibration noises...I think you may find that the cloth is going to be too dense ...You might want to listen to some low bass "before and after" your cloth is applied to hear if there are any differences in noise..

Good luck with install!
i was thinking of moving the cloth onto the exhaust ports themselves, but you might be correct it may be too dense. I will check to see if i can hear a difference with our without them.
 
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tadda

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i was thinking of moving the cloth onto the exhaust ports themselves, but you might be correct it may be too dense. I will check to see if i can hear a difference with our without them.
Moving cloth to exhaust ports would produce same results...Optimally, you really don't want to cover those ports with anything...I added the mesh for appearance only... I doubt any debris from the cargo area would get into the cavity...

Here are other options I also considered (replacing the 2" ports) which would secure to the narrow rear panel....

2" square grill cover

exhaust port cover.jpg


2" round grill cover

speaker grill cover.jpg
 
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Kiwi Greg

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I used 3m foam adhesive tape to secure mesh...The thickness of the 3m foam tape actually isolates the mesh from the wall and doesn't produce any rattles or vibration noises..
I used some bits of 3M tape & blobs of black silicon sealer to keep the mesh away from the metal

As mentioned there is a heap of air being pushed through the ports

This mod only cost me a few hours work & $90 Kiwi

Would have been way less with three lots of freight costing more than the components
 
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tadda

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I used some bits of 3M tape & blobs of black silicon sealer to keep the mesh away from the metal

As mentioned there is a heap of air being pushed through the ports

This mod only cost me a few hours work & $90 Kiwi

Would have been way less with three lots of freight costing more than the components

Total project cost for me was less than $35 USD...but most items also had free shipping as well!
 

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Quick question as i am not in front of my car as i just dropped it off at the shop but took the panel off already. Does anyone know approximately how far from the edge the holes should be cut? I was hoping to cut the holes while the shop does some work for me.
 
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tadda

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Quick question as i am not in front of my car as i just dropped it off at the shop but took the panel off already. Does anyone know approximately how far from the edge the holes should be cut? I was hoping to cut the holes while the shop does some work for me.
Center to center hole spacing is 19" ....Or each hole center is 9.5" from center of rear panel

subwoofer 6 2 inch foam insulation with ports dimensions.jpg
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