Modified OEM subwoofer?

[carguy75]

Has anyone tried to modify the OEM rear deck subwoofer by removing the front baffle that cover a good portion of the subwoofer opening?

I will attempt to remove the front baffle on my subwoofer to see if the bass response improves. The OEM speakers looks like a true 10in flat design woofer , but the front plate covers most of the woofer except for about a 6X9 opening facing the rear deck.

I am hoping that by removing the cover it will allow the woofer to have more output. Does anyone knows what the cover purpose is? My only reasoning is that it reduces the "boomy" bass output so that the bass is tighter and cleaner like it is now. However, I would like a little less tighter bass response.

Note: I did not remove my deck subwoofer, these are pictures for OEM Genesis subwoofer being sold on Ebay.

Here is what I noticed. Top cover held by screws and plastic tap welds it seems.

 

[GMCGenesisguy]

Hi! I think we are on the same page and both feel that bass is tight, and not boomy. I also prefer a boomy bass with better low end sound. Have you tried removing the subwoofer on your genesis yet? I am planning to do so soon, hopefully replace it with an aftermarket subwoofer. But wonder why is there two sets of wires running to the subwoofer? I also have the 17 speaker system.

 

[surprisinguy]

If you're just wanting more low end maybe just adding a sub box that will fit the trunk area... I saw one on here that looked like the back of the seat area in the trunk. Couldnt even tell it was an addon.

 

[kaigoss69]

The OEM subwoofer is installed in what is called an "infinite baffle" configuration. You can google it to find out what it is if you want. There needs to be a seal separating the sound waves coming from the front and the rear of the speaker, and the foam tape pictured does that job. If you remove the cover, and don't completely seal again, you will lose output due to cancellation of the sound waves. Also, the opening seems big enough to me and you would likely not have any increased output even if you were to re-seal around the speaker flange. Besides, to remove the speaker you have to remove the back seat and the hat shelf, which seems like a lot of work to have no audible improvement.

 

[carguy75]

The OEM subwoofer is installed in what is called an "infinite baffle" configuration. You can google it to find out what it is if you want. There needs to be a seal separating the sound waves coming from the front and the rear of the speaker, and the foam tape pictured does that job. If you remove the cover, and don't completely seal again, you will lose output due to cancellation of the sound waves. Also, the opening seems big enough to me and you would likely not have any increased output even if you were to re-seal around the speaker flange. Besides, to remove the speaker you have to remove the back seat and the hat shelf, which seems like a lot of work to have no audible improvement.

Well ,while the sound improvement statement is debatable; I do agree that it would be too much effort to remove the rear seat to actually do the test. I will most likely use a separate aftermarket sub-woofer to reinforce the factory setup.

The opening in the cover is only a 6inx9in opening; the OEM sub is a 10in sub-woofer, so the cover blocks a good portion of the sound. However, the bass respond would be muddy without the cover I suppose and not as clean hence its purpose I suspect. Therefore, it make play louder without the cover, but the output may not be very clean or desirable as with the cover.

I have seen a few slim sub-woofer boxes for sale that would most likely provide a stronger low-end punch to the stock system with a good crossover without taking too much trunk space and ruining the clean sound response.

Note: I already knew the stock sub-woofer was an infinite baffle design, most car speakers are designed to be free-air due to space saving requirements. However, I have never seen a cover plate on a woofer before. I can speculate that it is used to tune the woofer and control its output, but I really do not know it true purpose. So your post is educational but it still does not answer my question about the cover and its affect on the stock sub besides your speculation on its output without it.

 

[carguy75]

Hi! I think we are on the same page and both feel that bass is tight, and not boomy. I also prefer a boomy bass with better low end sound. Have you tried removing the subwoofer on your genesis yet? I am planning to do so soon, hopefully replace it with an aftermarket subwoofer. But wonder why is there two sets of wires running to the subwoofer? I also have the 17 speaker system.

I have not removed the stock woofer yet due to the labor required to remove the rear seat to access the rear deck. I will just purchase a slim-woofer to reinforce the stock sub output.

The stock woofer has two channels hence the two pair of wires.

I may just mount a sub like this on the rear seat inside the trunk to reinforce my stock sub-woofer. I will tap into the stock sub speaker output wires for a signal.
Cerwin Vega VPAS10 550W 10" Low Profile Amplified Subwoofer

 

[kaigoss69]

You may be thinking that sound behaves like light, which is not the case. Sound diffracts and "bends" around corners, which is why you can hear someone on the other side of a brick wall, but you can't see them. I came across an interesting article a few years back but I can't find it now. The discussion at the time was around this very subject - having a subwoofer partially blocked, and the effect on the sound coming from it. If I remember correctly, you had to block a substantial portion of the cone area before the output (dB) was negatively affected in a meaningful way. Having worked with subwoofer installations for a long long time, I can tell you that there is not going to be a meaningful difference if you opened up the front 100% vs. leaving it the way it is. The biggest difference will come from installing an aftermarket subwoofer, and amplifier.

 

[kaigoss69]

FWIW here is my solution to the weak factory bass. Works great.

 

[kaigoss69]

^^^ And by the way, it even sounds reasonably good with the armrest up.

 

[carguy75]

You may be thinking that sound behaves like light, which is not the case. Sound diffracts and "bends" around corners, which is why you can hear someone on the other side of a brick wall, but you can't see them. I came across an interesting article a few years back but I can't find it now. The discussion at the time was around this very subject - having a subwoofer partially blocked, and the effect on the sound coming from it. If I remember correctly, you had to block a substantial portion of the cone area before the output (dB) was negatively affected in a meaningful way. Having worked with subwoofer installations for a long long time, I can tell you that there is not going to be a meaningful difference if you opened up the front 100% vs. leaving it the way it is. The biggest difference will come from installing an aftermarket subwoofer, and amplifier.

Can you post some information about having a sub-woofer partially blocked. I used to be big into audio system installations back in the days, not so much now since many of my last few stock car audio systems sounded very good from the factory. No need to upgrade. Hell, my Genesis system sound great even with its subdue bass output. The bass is clean and tight, I just want a bid more punch.

Therefore, I understand how speakers work fairly well. Not an expert with an degree in acoustics, but know enough to get by.

I have never seen or read anything about partially covering a woofer. If you have some actually information on the subject then I would appreciate it if you posted a link. No offense , but I will not just take your word that a woofer can be blocked a certain percentage and still provide the same output as an unobstructed woofer. Goes against what I have learned over the years about proper sub-woofer installation. The only design that I have used that blocked the front of the woofer was bypass speaker designs which were tough to tune correctly. I assume that the stock OEM woofer is a type of band-pass free-air design that allows only a certain low frequency range out of the rear deck woofers.

______________________________

Help support this site so it can continue supporting you!

 

[carguy75]

FWIW here is my solution to the weak factory bass. Works great.View attachment 17341

Looks good. I bet sound great also. Any pics of it from inside the trunk?

 

[kaigoss69]

Looks good. I bet sound great also. Any pics of it from inside the trunk?

 

[carguy75]

View attachment 17342

Clean install.

What does the finish product look like?

 

[kaigoss69]

Clean install.

What does the finish product look like?

That's it .

I just kind of threw the sub in there; I had used it in a previous install. I may finish up a little with speaker and box cloth but honestly all I care about is how it sounds. The intent behind the install was to use the OEM signal and processing to basically replicate the output of the stock sub, but of course a hell of a lot louder. The distance of the sub to the listeners is the same as in the rear deck, so OEM time alignment works perfectly and allows for almost perfect blending/integrating with the front bass output of the door speakers. I have to really crank the output of the sub (via amp gain) before you know the sub is behind you. At that point the localization of the sub is due to rattles in the rear seat and deck, but the output signal is still perfectly aligned with the front stage. I would say it is an 8/10 in terms of blending with the rest of the system, which is all I could have asked for.

 

[carguy75]

That's it .

I just kind of threw the sub in there; I had used it in a previous install. I may finish up a little with speaker and box cloth but honestly all I care about is how it sounds. The intent behind the install was to use the OEM signal and processing to basically replicate the output of the stock sub, but of course a hell of a lot louder. The distance of the sub to the listeners is the same as in the rear deck, so OEM time alignment works perfectly and allows for almost perfect blending/integrating with the front bass output of the door speakers. I have to really crank the output of the sub (via amp gain) before you know the sub is behind you. At that point the localization of the sub is due to rattles in the rear seat and deck, but the output signal is still perfectly aligned with the front stage. I would say it is an 8/10 in terms of blending with the rest of the system, which is all I could have asked for.

Sounds like it does the job. I assumed that you also had a trim section for the rear of the sub that was part of the trunk floor cover.

I will just install a sealed sub and a crossover so that I can just get more low end bass around the 30hz range. I will only install a 10in woofer since I do not need want the "booming" bass like I used to have back in the days, but more punch that I can feel up front hopeful without the chassis rattles.

Hence why I was just going to remove the OEM sub-woofer front plate for more bass output from the factory sub-woofer. However, it would easier to just add a sub like you did instead of trying to modify the factory sub which may not be worth the trouble. When I first made this thread I assumed that the rear deck cover was easy to remove. I have since learned that you have to take apart the entire rear section just to remove the rear deck cover to access the stock sub. Therefore, I decided to put the factory sub modification on permanent hold.

 

[kaigoss69]

The challenge is to have the bass penetrate the back seat and get into the cabin. Usually, you can only achieve this with lots of output, and causing lots of trunk rattles. Leaving the Ski-pass open will help a little bit, but that is not always practical. A single 10 will be a stretch, but can work if implemented well. Look up "corner loading" and try to position the enclosure firing into the back corner vs. any other location in the trunk. Also, getting a 10" to play 30Hz and be tight at the same time is a very tall order!

 

[carguy75]

The challenge is to have the bass penetrate the back seat and get into the cabin. Usually, you can only achieve this with lots of output, and causing lots of trunk rattles. Leaving the Ski-pass open will help a little bit, but that is not always practical. A single 10 will be a stretch, but can work if implemented well. Look up "corner loading" and try to position the enclosure firing into the back corner vs. any other location in the trunk. Also, getting a 10" to play 30Hz and be tight at the same time is a very tall order!

Thanks for the tips. I will go for a sealed 10in since sealed enclosures can go deep but are fairly clean sounding. I will keep the stock sub so the aftermarket speaker just has to make enough bass to be "felt "up front without sounding muddy. I have made a few systems that were clean sounding and "bumpy" on the inside of the cabin with single 10in woofers. I do not need enough bass to be felt outside the car.

 

[kaigoss69]

Thanks for the tips. I will go for a sealed 10in since sealed enclosures can go deep but are fairly clean sounding. I will keep the stock sub so the aftermarket speaker just has to make enough bass to be "felt "up front without sounding muddy. I have made a few systems that were clean sounding and "bumpy" on the inside of the cabin with single 10in woofers. I do not need enough bass to be felt outside the car.

No problem. Out of all common enclosure types, sealed enclosures - especially small ones - are least efficient at low bass reproduction. You can get some deep bass out of them, but that usually requires a great deal of amplification, and a subwoofer with a strong motor and high power handling ($$$). Even then you will have a fairly steep roll-off below 40Hz. It all depends what you like and what you are willing to compromise on. Also, don't forget the Genesis trunk is very well sealed. What works in a Honda or Toyota, for example, does not necessarily work as well in our cars. Still, it is easy to try and you can return the box and sub if you don't like it and try another combination. In the Genesis - and other luxury sedans with well-insulated trunks - my experience has been that infinite baffle through the ski-pass works best, followed by a sealed box behind the ski-pass, followed by a corner-loaded fiberglass custom enclosure in the far trunk corner, followed by either a large sealed or ported standard enclosure, followed by a small sealed enclosure.

 

[carguy75]

No problem. Out of all common enclosure types, sealed enclosures - especially small ones - are least efficient at low bass reproduction. You can get some deep bass out of them, but that usually requires a great deal of amplification, and a subwoofer with a strong motor and high power handling ($$$). Even then you will have a fairly steep roll-off below 40Hz. It all depends what you like and what you are willing to compromise on. Also, don't forget the Genesis trunk is very well sealed. What works in a Honda or Toyota, for example, does not necessarily work as well in our cars. Still, it is easy to try and you can return the box and sub if you don't like it and try another combination. In the Genesis - and other luxury sedans with well-insulated trunks - my experience has been that infinite baffle through the ski-pass works best, followed by a sealed box behind the ski-pass, followed by a corner-loaded fiberglass custom enclosure in the far trunk corner, followed by either a large sealed or ported standard enclosure, followed by a small sealed enclosure.

Good advice. You are correct that a sealed box will need a lot of power to hit those low notes and the proper air space. The compact subs may not be enough to do an proper job. I was thinking about just paying an local audio shop to build me a custom 10in enclosure that fit in the recessed area of the trunk behind the rear seat. If I go that route I may have to dynamat the trunk area to reduce vibration as well.

I guess if you are going to do something, then you have to do it right.

 

[kaigoss69]

Good advice. You are correct that a sealed box will need a lot of power to hit those low notes and the proper air space. The compact subs may not be enough to do an proper job. I was thinking about just paying an local audio shop to build me a custom 12in enclosure that fit in the recessed area of the trunk behind the rear seat. If I go that route I may have to dynamat the trunk area to reduce vibration as well.

I guess if you are going to do something, then you have to do it right.

If you have them build it so it fires through the ski-pass (front of box sealed against back seat), then you will have no trunk rattles because no sound waves will enter the trunk. Easy and effective!