# Bass almost doubles with trunk open



## shweetpickens (Feb 8, 2016)

Sealed JL 13” preloaded box firing up at rear deck with 500 watt JL mono amp and integrated to factory system with audiocontrol LC7i. 

Small pass thru to cabin is open. When sitting In the driver seat with all the windows up in the bass playing as soon as I hit the trunk button and it cracks open the bass gets significantly louder and better. It’s almost as if the bass sounds right with the trunk open and stifled with it closed. The bass is almost doubled. Is there a reason for this? Can it be fixed without driving around with an open trunk? Lol

Side note: Bass gets noticeably better when I open the pass-through as seen in the picture but not as huge of a difference as when I open the trunk. 

I tried unplugging the factory sub in the rear deck and it doesn’t really change anything. I have contemplated removing the factory sub as well but it’s a pain to get to.

The system was professionally installed and all the settings are dialed in and tuned pretty well. I have moved the sub around to different spots but it doesn’t really make a huge difference. Maybe because it’s a newer Lexus and the trunk is sealed really well and is holding all the bass in?

Also I have the polarity at the sub reversed because when it was originally normal it just didn’t sound right and was slightly distorted with certain bass frequencies. I showed this to the installer and he agreed that it did sound better when the polarity is reversed so I’ve left it that way.


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## shweetpickens (Feb 8, 2016)

I might have found an answer to my own question. Still open to other input though as well.

https://www.installer.com/tech/index.php?page=aiming


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## jrwalte (Mar 27, 2008)

and you did. Can you tilt the box on one of its side and test it? You won't be able to drive around that way but can find out, in your case, if rear aiming close to trunk gives you what you want. You'd have to find a way to mount it or get a new box.


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## shweetpickens (Feb 8, 2016)

jrwalte said:


> and you did. Can you tilt the box on one of its side and test it? You won't be able to drive around that way but can find out, in your case, if rear aiming close to trunk gives you what you want. You'd have to find a way to mount it or get a new box.


That’s my concern. I’m not sure it will be feasible to put the box where that’ll article suggests unless I don’t drive my car or don’t use the trunk for anything else....


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## 1styearsi (Aug 13, 2012)

i always have better luck firing back.


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## Bayboy (Dec 29, 2010)

In a coupe or sedan, you have 3 boxes. The sub box (1), the trunk (2), and the cabin (3). Eliminate the second box... the trunk of possible. I prefer to have the sub box sealed off from the trunk and firing directly into the cabin whether it's through the rear seat IB style (if it isn't solid), ski-pass, or rear deck. 

Sent from my SM-G955U using Tapatalk


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## Jroo (May 24, 2006)

sometimes you just have to play with placement. Years back I had a sealed solobaric and had to play with it for a couple of weeks. I would drive a few days with it one direction and then switch. In that car it sounded best to my ear pointed up. Other cars I had later it sounded best pointed back. The best sound overall was a 4th order ported through the ski pass.


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## shweetpickens (Feb 8, 2016)

Yea I’ve heard the band pass box ported into the cab sounds great.

Thanks for all of the feedback. Yea I’ll move it around. I’m trying to figure out how I’m going to get that tall skinny box to stay still in different positions. Right now with it face up and Velcro on the back it won’t move. I matter what lol


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## subterFUSE (Sep 21, 2009)

Classic example of the bass reflecting off the trunk lid and cancelling with the direct sound. Best solution is to aim the subwoofer so it fires at the rear of the car, and then move the subwoofer as far to the back of the trunk lid as possible. You essentially want the sub firing into the back of the license plate.

Is that practical? Not very. But it does fix the cancellation issue, most likely.


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## openglcg (Jun 23, 2018)

There are many reasons why you might not want to do this but have you thought about an actual 4th order enclosure?


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## shweetpickens (Feb 8, 2016)

openglcg said:


> There are many reasons why you might not want to do this but have you thought about an actual 4th order enclosure?


I haven’t. I have a cost and effort limit to how much I’m willing to put into this. I purchased what should be an excellent sub/enclosure combo and am not really willing to pay someone to customize it further. Now if I had a do over I might, but something tells me it would cost much more than I am willing to spend. $400 got me the JL 13” thin line preloaded sub and enclosure, audiocontrol lc7i, and JL JX500/1 500w mono amp. Can’t beat that


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## shweetpickens (Feb 8, 2016)

It is confirmed: bass is better, louder , and punchier when I face my sub a few inches away firing at the rear trunk. Now opening the trunk during bass notes doesn’t increase the bass inside the cabin.

Now I just need to figure out how to secure it that close to the trunk. I can actually move it all the way to the left or the right as long as it’s firing back at the trunk it still sounds good


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