How to Improve OE Sub Bass Quality and Eliminate Vibrations

[30MilesOffshore]

(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.

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[30MilesOffshore]

(4) Rear Trunk Latch Wall

I did the backside of the plastic cover and also the sheet metal below the latch.

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[30MilesOffshore]

Just finished adding the foam and taken her for a spin down the block. I gotta say I'm pretty happy with the overall results! If you're on the fence about doing this mod I highly recommend it! It will make a difference in the sound quality. Thanks for everyone that contributed!

 

[tadda]

Just finished adding the foam and taken her for a spin down the block. I gotta say I'm pretty happy with the overall results! If you're on the fence about doing this mod I highly recommend it! It will make a difference in the sound quality. Thanks for everyone that contributed!

Glad to hear everything worked and thanks for your contibutions as well!

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I'm onto the doors next...This project won't be nearly as involved as this current project was, but I have identified some areas within the door cover, surrounding the midrange area, that does require some sound deadening material applied to eliminate some midbass vibrations...JasonO has already started this....

At this point I see no need to play with crossovers...I'm waiting for a 7 channel DSP amp for the Supra which should be released within the next month or so that will be my next system upgrade...I still standby my assessment that the current Harmon Kardon speakers are actually quite good and that after I install an amp upgrade I'll then determine if replacing the HK speakers will be needed...

 

[Supbrah]

Glad to hear everything worked and thanks for your contibutions as well!

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I'm onto the doors next...This project won't be nearly as involved as this current project was, but I have identified some areas within the door cover, surrounding the midrange area, that does require some sound deadening material applied to eliminate some midbass vibrations...JasonO has already started this....

At this point I see no need to play with crossovers...I'm waiting for a 7 channel DSP amp for the Supra which should be released within the next month or so that will be my next system upgrade...I still standby my assessment that the current Harmon Kardon speakers are actually quite good and that after I install an amp upgrade I'll then determine if replacing the HK speakers will be needed...

When you get the inner door panel off, if you don’t mind, would you take a few photos of backside of the panel? I want to see if the armrests can be removed.

 

[tadda]

When you get the inner door panel off, if you don’t mind, would you take a few photos of backside of the panel? I want to see if the armrests can be removed.

Sure...I'll be posting plenty of pics of the backside of the door panel...Will most likely be posted in another thread focusing on door speakers ...

 

[tadda]

New thread created below....This is Part 2 in a series of on how to improve the Supra's OE audio system sound quality, clarity, and eliminate vibrational noise and distortions...

Improving OE Door Speaker Clarity and Depth

 

[Kgsweb]

OK. I did everything that Tadda recommends and can only say WOW. Marked improvement in the clarity and volume of the low end. This should be done by every Supra owner that wants to get the most out of the stock system. The bass is tight and punchy.

Now, if we could only find a way to raise the pre-amp volume of all the inputs to match that of the SiriusXM
input.

 

[tadda]

I thought this might be useful for those interested in how to set up the sound system equalizer to optimize sound quality...The EQ setup and results shown in the linked thread below were done after implementing some much needed design improvements to OE Subwoofer System...

How to Setup and Optimize Sound Quality using OE Equalizer

 

[ScottyMemphis]

Yet another satisfied customer here. I performed these steps on my Supra yesterday and all rattling/vibrations are gone.

Thanks a million for taking the time @tadda

 

[tadda]

Bavsound just released at very good instructional video on how to replace the Supra OE subs...Surprised and pleased to see how they streamlined the process with not many panels needing to be removed to replace the subs...

 

[30MilesOffshore]

Video is good but in the video above the aluminum crossbeam (tranvserse pipe) that goes across the back of the car is missing. This will need to be removed and reinstalled too in order to get the upper quarter panel reinstalled. There is no way that you will get the upper rear quarter panel reinstalled with the pipe still in place. You can take the upper quarter panel off with the beam installed but in order to get it back on you will need to remove the pipe, reinstall the quarter panel, and then reinstall the pipe again.

Having the rear sub deck only an inch or two above the woofer enclosure makes for some really awkward angles. Installation can get tedious and frustrating. They didn't use one but I would recommend a ratcheting bar clamp to help. Use the clamp in reverse to help spread and hold the sub deck away from the sub. You can pick one up form Harbor Freight for $4.

However you will still be limited on clearance because they didn't remove the two lower rear quarter panels and the sub deck will still be locked in place behind the seats and putting alot of pressure on the top. The sub deck housing is L shaped and has locks in place behind the seats. This makes it extremely aggravating to hold the deck up and work if you don't relieve the pressure. I slid the deck up off of the hooks and was able to pry the deck up pretty high with the ratcheting bar.

In the end, I would say that the only two pieces not removed in the video are the (lower rear quarter panels & lower door trim). The lower rear quarter panels are located behind the seats next to the doors. And the lower door trim is right next to the seat when you get in/out of the car. At this stage of removing panels, both of these pieces pop out easily when compared to the upper rear quarter panel.

My recommendation would be to go ahead and take those pieces off too. If you're going to remove that many body panels go ahead and install sound dampening and foam back there. I would dampen the black plastic sub housing and also all metal ports that the woofers fire into. Also don't forget to do the foam install. It will dramatically make a difference.

I would be curious to hear a sound difference between two sound systems (1) car that only had the subs replaced and (2) a car that had factory subs but has been properly dampened with matting and foam.

Overall, a good video but I see alot of aggravation and frustration by not removing the two other panels. They removed 6 panels plus the pipe. Yes you can do it that way but in the end, you will encounter some issues. If you're gonna replace the subs you will most likely want to dampen & foam the sub area too. A harder hitting or tuned sub will just create more vibration issues anyway. Just do the job completely and correctly the first time you go in there.

 

[tadda]

Thanks for the feedback @30MilesOffshore

Yeah, clearly the intent of the video here is just to remove and replace the sub speakers from their plastic enclosures and not the entire subassembly...

I do appreciate the time they took to finally release a detailed installation video and straight forward approach of replacing the OE subs...The owner of that Supra had removed that crossbeam (not sure Bavsound realised that) so that's why it wasn't shown and it's not really a big deal to remove....The removal of only 6 panels and a cross beam to just replace subs is far less time and effort than having to remove 12 pieces and a cross beam...

Aside from the bungy / cross beam method of holding up the cover you can also place a block under the center of the cover once you have it lifted to keep it supported...This is what I did awhile ago without having to remove those lower panels and center console pieces...

I'm going to try and follow their video tomorrow as I've been wanting to disconnect the rear midrange and tweeter speakers located behind the seats which are fairly useless...I'll let you guys know how it goes with following the video as it appears fairly straight forward...

I am also very curious as to how the Bavsound Subs would sound along with the improvements made to the sub enclosure which is outlined in this thread...My research found that most, if not all of the vibrations in the OE subwoofer system, simply came down to having the 3 elongated metal enclosure ports blocked / covered by the narrow rear cover panel...Clearing that path (along with some foam insulation added) all but eliminated a majority of the vibrations and at the same time also lowered the system Q allowing for a much deeper / punchier / less distorted bass response...Hearing some of the feedback regarding the Bavsound subwoofer having a clearer / punchier bass response but somewhat lacking in low end response, I would imagine that having the ports path cleared would only help to improve their low bass response as well...What I do find intriguing about the Bavsound subs is that they apparently have a higher power handling capability along with a higher efficiency / sound output which would play nicely with a future DSP amp upgrade...

 

[30MilesOffshore]

Yeah, it's definitely good stuff and opens the window for improvement and modding the system to one's particular taste. I'm glad Bavsound did post up to show that it isn't as bad as some people might anticipate it being. If someone was reluctant on doing any of the mods mentioned, I would say don't wait and have at it! The beauty of the system is that you can do an a-la-carte and just do one simple mod and getting success or go all in and gut the entire system to aftermarket.

Keep us posted on your progress with disconnecting the rear speakers. With my setup, I actually use them on a daily basis. I have the fader set to give me an approximate equal balance between the front and rear speakers (at least to my ears). Just curious as to what direction you plan to go by disconnecting them?

 

[tadda]

Yeah, it's definitely good stuff and opens the window for improvement and modding the system to onKeep us posted on your progress with disconnecting the rear speakers. With my setup, I actually use them on a daily basis. I have the fader set to give me an approximate equal balance between the front and rear speakers (at least to my ears). Just curious as to what direction you plan to go by disconnecting them?

I disconnected the rear (behind the seat) speakers simply because the way in which the OE amp is set up I estimate that maybe 5~10% of total power from the amp is dedicated to those speakers which is the reason why there is not much sound coming from them to begin with regardless of any fade or "sound enhancement" setting applied...I've extensively played with all configurations, isolating the rears to evaluate their contributions to the system, and found they really weren't of any value ...In the mean time, I'd much rather have the OE Amps' limited power directed solely on remaining OE speakers that do add value such as the door, center, and subs....Another reason for deleting them is that the rears are located directly behind the seats and since mid and high freq sound are highly directional, the little bit of power that is dedicated to those rear channels, is further attenuated by having the seats nearly up against those speakers blocking what little sound they do produce...

The direction I've decided to go in (of coarse subject to change..ha!) will be to take advantage of the door and front center speakers (keeping them OE), replace the OE subs (still using the same enclosures) with higher power handling / tighter woofers which will be eventually used as bass speakers and then add an additional subwoofer (similar to what OEMaudio+ is planning on offering) with DSP Amp powering the system. Once a new DSP amp is installed I may go back to re-evaluate using the rear (behind the seat speaker) since I'll have the capability of programming the amp to provide more useful power to them...

Side note...I was excited to hear about the OEMaudio+ sub and DSP amp system that they plan on offering soon but was disappointed to find out they eliminate the 2 OE woofer locations in the process...Having sorted out all the issues regarding our OE sub enclosure and quite content with the results I feel they should have kept the OE woofers in same location using them strictly as bass speakers in addition to the OEM+ dedicated subwoofer...

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