How to Improve OE Sub Bass Quality and Eliminate Vibrations

pav911

Well-Known Member
First Name
Pav
Joined
Jun 27, 2020
Threads
5
Messages
86
Reaction score
37
Location
Peterborough, UK
Car(s)
Range Rover, Mini JCW
I use wireless apple CarPlay. does that send the sound over bluetooth?

Re EQ settings, I use the ones on this thread as a benchmark and then usually have to turn the bass down.

The OEMAudio+ solution looks good, but there's no indication as to when it will be available.
Sponsored

 
OP
OP
tadda

tadda

Well-Known Member
First Name
Tom
Joined
Dec 14, 2019
Threads
24
Messages
1,251
Reaction score
2,157
Location
Arizona
Car(s)
2023 C8 Corvette Z51 2LT Coupe
Vehicle Showcase
1
I use wireless apple CarPlay. does that send the sound over bluetooth?

Re EQ settings, I use the ones on this thread as a benchmark and then usually have to turn the bass down.

The OEMAudio+ solution looks good, but there's no indication as to when it will be available.
The audio quality is extremely compressed and degraded over both bluetooth and broadcast music...That's probably why your finding yourself disappointed in the bass quality...I have my entire music library loaded onto a usb thumbdrive and the music quality is far better with much deeper and clearer bass response...

OEMAudio plus is very delayed with their release....Your probably looking at late this year at best....Also as I've discussed with them I am disappointed that they totally delete the OE woofers in place of their one sub which I think is a major shortcoming ...What they should have done is left the OE subs and treated them as mid-bass speakers in addition to their adding their own subwoofer...

What would make a noticeable improvement to the existing OE system would (along with current sub improvements) be to add 100hz crossover to existing OE subs to use them as midbass speakers and then tap into one of the existing OE woofer leads and connect to an high/low converter and add either a powered sub or external dedicated amp to a sub...
 

pav911

Well-Known Member
First Name
Pav
Joined
Jun 27, 2020
Threads
5
Messages
86
Reaction score
37
Location
Peterborough, UK
Car(s)
Range Rover, Mini JCW
The audio quality is extremely compressed and degraded over both bluetooth and broadcast music...That's probably why your finding yourself disappointed in the bass quality...I have my entire music library loaded onto a usb thumbdrive and the music quality is far better with much deeper and clearer bass response...
I'll try with my phone connected using a USB cable.

What would be a noticeable improvement would be to add 100hz crossover to existing OE subs to use them as midbass speakers and then tap into one of the existing OE woofer leads and connect to an high/low converter and add either a powered sub or external dedicated amp to a sub...
This is what I was thinking too. I wish I had the skills to do this myself.
 
OP
OP
tadda

tadda

Well-Known Member
First Name
Tom
Joined
Dec 14, 2019
Threads
24
Messages
1,251
Reaction score
2,157
Location
Arizona
Car(s)
2023 C8 Corvette Z51 2LT Coupe
Vehicle Showcase
1
I'll try with my phone connected using a USB cable.


This is what I was thinking too.
If your listening to streaming music being broadcast over air, connecting your phone to USB still isn't going to yield the best quality audio...Broadcast / streaming audio is very compressed and distorted which takes up a fairly narrow band...
 

pav911

Well-Known Member
First Name
Pav
Joined
Jun 27, 2020
Threads
5
Messages
86
Reaction score
37
Location
Peterborough, UK
Car(s)
Range Rover, Mini JCW
Aah. That's what you meant. ok...though I do tend to download the songs to my phone, but I guess even that is not at a great bitrate.

that just adds to my dilemma....what's the point of spending money upgrading the system if my source is going to let it down.
 
OP
OP
tadda

tadda

Well-Known Member
First Name
Tom
Joined
Dec 14, 2019
Threads
24
Messages
1,251
Reaction score
2,157
Location
Arizona
Car(s)
2023 C8 Corvette Z51 2LT Coupe
Vehicle Showcase
1
Aah. That's what you meant. ok.
I've found that streaming music through satellite and playing via bluetooth is the worst quality...If you downloaded mp3 music files onto your phone and play that through the USB that should sound much better....I listen to all my music download onto a usb thumb drive...

I also enjoy EDM, Trance, and Ethereal Techo which has some of the deepest bass deep tracks out of most music genres...I find that the bass response with the improvements made are very deep and clear...but only to a point....Past 2/3 volume it's the amplifier itself that begins to distort and becomes the limiting factor...
 
Last edited:

Lil Grey Supra

Well-Known Member
First Name
Michael
Joined
Aug 31, 2020
Threads
2
Messages
47
Reaction score
45
Location
Missouri
Car(s)
94 Camaro - 427ci LSX turbo'd, 2016 RAM 2500, 2021 GR Supra 3.0 Prem
Nope. No Madonna will be played in the car. Lol. Definitely try uncompressed formats....huge difference. Even different Sirius channels have different quality. Agree with all above, fix the design, improve the source, and you should be much happier
 

Ultimateone

Well-Known Member
Joined
Feb 13, 2020
Threads
20
Messages
659
Reaction score
568
Location
Boston
Car(s)
AW A90
i use an old Ipod with like 10k songs on it as I know I am getting a great sound versus bluetooth streaming etc
 

pav911

Well-Known Member
First Name
Pav
Joined
Jun 27, 2020
Threads
5
Messages
86
Reaction score
37
Location
Peterborough, UK
Car(s)
Range Rover, Mini JCW
So after more playing around with the equaliser, testing with different tracks and trying wired and wireless CarPlay I've come to the conclusion that there's no point spending money on upgrading the speakers or adding additional speakers until I've figured out where my vibrations are coming.

After doing the mods on this thread I can still hear vibrations from behind me. I haven't put the sound deadening stuff on the boot (trunk) floor yet, but I'm not sure that will help. It still feels like the vibration is coming from the big bit of carpeted trim that the subwoofers sit in.
 

Ultimateone

Well-Known Member
Joined
Feb 13, 2020
Threads
20
Messages
659
Reaction score
568
Location
Boston
Car(s)
AW A90
Right behind our seats I put in some foam also that stopped some vibrations, the bottom you can kinda pull out and stuff it up there.
 
OP
OP
tadda

tadda

Well-Known Member
First Name
Tom
Joined
Dec 14, 2019
Threads
24
Messages
1,251
Reaction score
2,157
Location
Arizona
Car(s)
2023 C8 Corvette Z51 2LT Coupe
Vehicle Showcase
1
So after more playing around with the equaliser, testing with different tracks and trying wired and wireless CarPlay I've come to the conclusion that there's no point spending money on upgrading the speakers or adding additional speakers until I've figured out where my vibrations are coming.

After doing the mods on this thread I can still hear vibrations from behind me. I haven't put the sound deadening stuff on the boot (trunk) floor yet, but I'm not sure that will help. It still feels like the vibration is coming from the big bit of carpeted trim that the subwoofers sit in.
As I recall in your last post you were having issues with bass response and not vibrations? So were you able to hear an improvement in bass response by listening to a higher quality / uncompressed music source?

That's interesting that your still experiencing vibrations? Mine are all but gone...I'm also curious as to how closely did you follow my original post ? If you haven't done so already look at the grills as they were a source of vibration...I outline in my first post as to how to resolve this...Also adding adhesive backed foam in areas I high-llghted help greatly...I do call out a few other areas where I also applied foam insulation and sound deadening material...

Here is another area below where I stuffed with foam blocks....

upload_2020-9-24_13-44-19.png


Let us know how things go to resolve your other vibration issues...
 
Last edited:

pav911

Well-Known Member
First Name
Pav
Joined
Jun 27, 2020
Threads
5
Messages
86
Reaction score
37
Location
Peterborough, UK
Car(s)
Range Rover, Mini JCW
(3) Rear Lower Deck

This are is pretty straight forward. I just did section strips being sure to not cover any nuts, bolts, wires, etc. You don't have to cover an entire piece of metal with dampening to change the vibration response of the metal. Of course, the more the better, but any amount will have some affects.

234.jpg


235.jpg


236.jpg


237.jpg


238.jpg
I think I'd like to do this next. Just need to muster up the courage to take the car apart.
 

pav911

Well-Known Member
First Name
Pav
Joined
Jun 27, 2020
Threads
5
Messages
86
Reaction score
37
Location
Peterborough, UK
Car(s)
Range Rover, Mini JCW
As I recall in your last post you were having issues with bass response and not vibrations? So were you able to hear an improvement in bass response by listening to a higher quality / uncompressed music source?
I started off with the EQ settings in the first post, but after time and multiple tweaks I ended up with settings that made the bass sound worse. Resetting back to the settings in the first post made a huge improvement to the bass. Even on the Justify My Love track. So I sat in the car for ages listening to loads of different tracks again and that's when I started noticing the vibrations again.

I glued the grill together so I don't think it's them. I'm planning on removing them though and listening again to see if that is where the vibration is coming from.
 
OP
OP
tadda

tadda

Well-Known Member
First Name
Tom
Joined
Dec 14, 2019
Threads
24
Messages
1,251
Reaction score
2,157
Location
Arizona
Car(s)
2023 C8 Corvette Z51 2LT Coupe
Vehicle Showcase
1
I think I'd like to do this next. Just need to muster up the courage to take the car apart.
You really don't need to take the car apart...I also don't think those areas on the black plastic subwoofer enclosure are necessary....I've already explored them and the way in which they are designed those surfaces will not cause any vibrations...

Try stuffing some foam blocks in the area shown below....

upload_2020-9-24_13-44-19-png.png


Also a huge source of vibration came from the rear cargo floor panel...I outline how to resolve this in my first post
 

pav911

Well-Known Member
First Name
Pav
Joined
Jun 27, 2020
Threads
5
Messages
86
Reaction score
37
Location
Peterborough, UK
Car(s)
Range Rover, Mini JCW
I'm also going to try this.

Some additional improvement tips (update added to original post):

For those that have completed this project, which involved lining the walls of the speaker enclosures, placing foam insulation between enclosure and narrow rear panel, and adding exhaust ports, I've also identified that there is one final area that needs to be addressed....

I discovered this after implementing all these other improvements, thus allowing me to significantly increase volume along with raising bass EQ settings...What I found was that there was some exhaust port energy escaping from under the long narrow rear panel (which as I show in a few pics below) causing the rear floor panel cover to vibrate...Keep in mind that this is yet another design problem which causes the floor panel cover to vibrate where in-turn this vibrational energy is transferred to the cargo areas' side and back panels causing them to vibrate as well...

The solution here was to apply some adhesive back foam to the areas show below which eliminated any energy transfer under the rear floor panel cover...

Shown below, I first applied 1.5"d x 4" L x 0.25" h adhesive backed foam strips above and below both exhaust ports
to isolate them further from the top cover and floor....

subwoofer 7b ported rear panel insulation strip.jpg


Next, the image below shows where some exhaust energy from the 3 elongated ports was also being released under the large rear floor panel cover causing it to vibrate greatly...With the floor panel removed simply place your hand under the narrow panel and you'll see / feel the exposed gap ...

subwoofer 2a narrow rear panel exhaust port leak.jpg


Below shows locations where 2 adhesive back foam strips were applied to underside of exposed narrow rear panel ...The left adhesive backed foam strip was 1.5"D x 11" L x 0.25" H and the right foam strip is 1.5"D x 6" L x 0.25" H...This essentially sealed off the gap where the exhaust energy was also being channeled...
subwoofer 2a narrow rear panel foam strips.jpg


As a result the large rear floor panel cover vibration has pretty much been eliminated and side and rear trunk panels no longer vibrate during low bass / high volume music passages....

As far as materials, I used Noico RED 315 mil Sound Insulation , which I already had available for beginning my next project of eliminating front door speaker vibrations ....
Sponsored

 
 




Top