[bentz69]

I have 1 JL Powerwedge+ (ACS110LG-TW1) installed in the trunk of Mercedes CLS63 with the rest of the stock Harmon Kardon system. Although this sub/amp only pushes 400w RMS, its enough for me ONLY when the rear seat is folded down. Unfortunately there is no pass through in the seat and leaving the rear seat folded down all the time is not really practical.

I believe the trunk is very well sealed from the factory and when the seat is latched closed, the air just doesn't get into the cabin. The bass sounds soft and does not hit hard. When the seat is down, the bass is much louder, cleaner and sooo many fewer rattles in the rear shelf. What options do I have here?

I thought about removing the stock sub to get more air movement into the cabin. Its disconnected anyway because it rattles when connected. The stock sub is very small so it might be hit or miss considering the size of the space that will now be open. The white circle would be area that is now acting as a passthrough for air.

Ditching the powerwedge+ entirely and getting something more powerful. However, this will probably cause that rear shelf to rattle even more.

Is the sealed style of the powerwedge+ limiting air movement in the trunk? Will a ported box will sound better considering the enclosed nature of the trunk?

 

[Ali-323i]

Removing the speaker is a good idea, and may help a bit but probably not enough on its own.

I had a similar issue in my bmw, ended up cutting my own ski hole behind the rear armrest.

I now use it for a trunk IB, but even before that it made a HUGE improvement getting bass into the cabin.

 

[bentz69]

Removing the speaker is a good idea, and may help a bit but probably not enough on its own.

I had a similar issue in my bmw, ended up cutting my own ski hole behind the rear armrest.

I now use it for a trunk IB, but even before that it made a HUGE improvement getting bass into the cabin.

The seat that the sub is attached to is the driver side and also includes the center arm rest. I went with the powerwedge+ to save trunk space and securing it to the back of the seat was the best spot. Not sure how I could re position the box if I wanted to make hole in the arm rest.

I really would consider this option to make a hole in the armrest. The blue circle is just a piece of plastic and behind it is the wood followed by carpet.

This got me thinking. What about creating a hole on the back of the seat, flipping the box and firing the sub directly through the hole. The box would have to placed in the middle basically attaching itself to both seats. Thoughts?

On the drive home tonight I had only the passenger side rear seat completely down for half the ride. The other half I had only the driver side rear seat unlatched and leaning against the latch itself. It leaves about a 1 inch gap. Both scenarios sounded the same to me. Bass was equally as loud, cleaner and surprisingly no rattles in the rear shelf. This gives me some hope that removing the stock woofer might allow enough air to pass given the small space.

 

[lithium]

In theory you need about 50% open area of the cone size to transfer bass into the cabin. Typically this applies to a manifold situation but I see no reason why it wont hold up. I would try removing rear speakers and/or sub first. You could also experiment with some gadget to partially open one side of the rear seat to allow bass out but still give the appearance of an closed rear seat. Obviously you would want something removable for passengers. Modifying the arm rest is also a good option but really its not more area than just removing the rear stock sub/speakers and you're modifying expensive trim panels. Due to path lengths and other jazz one may be better than another but you would need to experiment.

 

[cathul]

I removed the rear speakers on my Mustang for that exact same reason.

 

[Ali-323i]

I really would consider this option to make a hole in the armrest. The blue circle is just a piece of plastic and behind it is the wood followed by carpet.

This got me thinking. What about creating a hole on the back of the seat, flipping the box and firing the sub directly through the hole. The box would have to placed in the middle basically attaching itself to both seats. Thoughts?

That’s kinda what I did, the sub fires directly through the arm rest hole I created. The only difference is that mine is an IB install, not a box.
I think it can work well, but the sound signature will change without having the bass rebound off the back of trunk first, and ideally you’d want to seal around the sub so that all output gets forced into the cabin.

I’d defo consider something similar, but after you’ve first tested the removal of rear deck speakers to see if that alone can provide sufficient results.

Attached some pics of my setup.

 

[Theslaking]

Removing the rear sub will do more than you think. I have had the same situation in a couple vehicles. I would cut a bigger hidden hole in nthe rear deck before I cut a hole in the seat.

 

[datooff]

You definitely need to vent the rear deck with this kind of installation.

 

[Theslaking]

And don't just stick a sub where someone else did. Loading/cancellation is different for each car situation. Experiment with sub placement first, then cut if venting the rear deck is not sufficient.

 

[bentz69]

It might sound ridiculous but in this car, removing the rear seat to cut a hole through the pass-through is much easier then removing the rear shelf to take out the sub. But it only makes sense to remove the stock sub first to see the effects.

 

[cflores2]

Check out the matt Shawffer build he did on the Bentleys gives you an idea of what works- on YouTube

 

[nauc1]

buy a Honda! 😜

 

[bentz69]

What do you guys think. I have this alpine swr-1023d in a sealed box sitting in the basement for years. Is this a "better" sub then the JL?

 

[SHAGGS]

The Alpine is a solid sub. It may preform better in terms of output. What amp are you planning to push it with?

 

[bentz69]

The Alpine is a solid sub. It may preform better in terms of output. What amp are you planning to push it with?

Open for suggestions but the Alpine s-a60m comes to mind

 

[LinkyPwns]

OP, I have a similar situation in my Taurus. When one of my backseats are down you hear so much more of the sub. I do not have an armrest opening either.

You got me contemplating taking out my two rear shelf 6x9 factory “subs.” The only thing that concerns me is road noise. When those seats are open I hear so much more road noise that I think I’d rather just leave it as is.

Do you hear a lot more road noise when your rear seat is down?


Sent from my iPhone using Tapatalk

 

[bentz69]

OP, I have a similar situation in my Taurus. When one of my backseats are down you hear so much more of the sub. I do not have an armrest opening either.

You got me contemplating taking out my two rear shelf 6x9 factory “subs.” The only thing that concerns me is road noise. When those seats are open I hear so much more road noise that I think I’d rather just leave it as is.

Do you hear a lot more road noise when your rear seat is down?


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When I fold one seat completely down I get better air movement and much better base at the expense of added road noise on the highway. I dont need both seats down to get better base. In fact, after experimenting, just leaving one seat leaning against the closed latch provides the same bass as a fully open seat without the road noise. This gives me hope that removing the stock sub wil be sufficient

 

[TomV]

You can mount the JL sub underneath the rear deck, like I did mine in my Lincoln MKZ.

 

[bentz69]

You can mount the JL sub underneath the rear deck, like I did mine in my Lincoln MKZ.
View attachment 332887 View attachment 332888

Thats pretty cool. Unfortunately I have a oem pull out storage bin that sits under the rear shelf.