Subwoofer Bass not leaving TRUNK
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I just installed a system in my 2006 GS300. This is similar to the newest body style minus the extra horse power.
Installed MM6501 Polk Audio Components in the front
DB6501 Polk Audio Components in the rear
JL 12W3v3 subwoofer in the trunk
The shop installed the sub in a custom box with a flush panel and the port at the top of the box. They removed the stock woofer so the box is ported into the cabin.
Problem: The bass isn't hitting hard when the trunk is closed. I know it's not the sub because I can see the sub hitting really hard with the trunk door open. Has anyone else encountered this problem? I've definitely got enough juice going to the sub as I have 400watts coming from a Polk 1100.5 amp. The box is up against the back seats with the woofer facing the back of the car. I noticed when the box is in the middle of the car, that it sounds much better than when up against the seat. When it's up against the seat, I can hardly tell I have a woofer. The shop told me it had to do with the insulation of the Lexus blocking most of the bass.
I appreciate your advice. Thanks.
Installed MM6501 Polk Audio Components in the front
DB6501 Polk Audio Components in the rear
JL 12W3v3 subwoofer in the trunk
The shop installed the sub in a custom box with a flush panel and the port at the top of the box. They removed the stock woofer so the box is ported into the cabin.
Problem: The bass isn't hitting hard when the trunk is closed. I know it's not the sub because I can see the sub hitting really hard with the trunk door open. Has anyone else encountered this problem? I've definitely got enough juice going to the sub as I have 400watts coming from a Polk 1100.5 amp. The box is up against the back seats with the woofer facing the back of the car. I noticed when the box is in the middle of the car, that it sounds much better than when up against the seat. When it's up against the seat, I can hardly tell I have a woofer. The shop told me it had to do with the insulation of the Lexus blocking most of the bass.
I appreciate your advice. Thanks.
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#2
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Your box is sealing off the trunk from the cabin. You should have gone with a different design or put the sub in a different orientation. Can you fire the drivers towards the front of the car?
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I have mine ported through the stock subwoofer hole. They took out the speaker so the air can come thru. Banda, how is your setup going to be any different? Do you think if I took off the flush panel, and used the same box, that it would hit hard because there would be room for air?
Any other GS owners encounter this problem?
Any other GS owners encounter this problem?
#5
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Firing backwards is the best way for sure and in the position you have yours is generally the best... if the port is firing in to a different airspace than the sub is in, or if the port is firing the opposite direction the sub is facing, it can cause the output to roll off - it detunes the port to an extent and can cause the port to even cancel the sub some... With ported subs, I've always had the best luck with the port facing at a 90 degree angle to the sub inside the box with the port sharing the airspace of the sub, with second best which is having the port on the same face as the sub itself....
In my old SC400, I had a 13W1 and output was quite good, even with the fuel tank between the trunk and back seats... sub was facing backwards, as was the port...
No matter what, it will never be as loud as the same setup in a hatchback...
If it were me, I would change the location of the port... Also make sure the port is correct for the sub - generally installers are pretty good at this, but not every time... How big is your box? the proper box for a 13w3 is either 2.25 or 2.5 cu ft plus the airspace used by the port and subwoofer... With just a rectangular box in my SC, it took up a good portion of the trunk...
http://mobile.jlaudio.com/products_s...p?series_id=26
You can see there that the port is forever long and huge, as is the box...
In my old SC400, I had a 13W1 and output was quite good, even with the fuel tank between the trunk and back seats... sub was facing backwards, as was the port...
No matter what, it will never be as loud as the same setup in a hatchback...
If it were me, I would change the location of the port... Also make sure the port is correct for the sub - generally installers are pretty good at this, but not every time... How big is your box? the proper box for a 13w3 is either 2.25 or 2.5 cu ft plus the airspace used by the port and subwoofer... With just a rectangular box in my SC, it took up a good portion of the trunk...
http://mobile.jlaudio.com/products_s...p?series_id=26
You can see there that the port is forever long and huge, as is the box...
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Firing backwards is the best way for sure and in the position you have yours is generally the best... if the port is firing in to a different airspace than the sub is in, or if the port is firing the opposite direction the sub is facing, it can cause the output to roll off - it detunes the port to an extent and can cause the port to even cancel the sub some... With ported subs, I've always had the best luck with the port facing at a 90 degree angle to the sub inside the box with the port sharing the airspace of the sub, with second best which is having the port on the same face as the sub itself....
In my old SC400, I had a 13W1 and output was quite good, even with the fuel tank between the trunk and back seats... sub was facing backwards, as was the port...
No matter what, it will never be as loud as the same setup in a hatchback...
If it were me, I would change the location of the port... Also make sure the port is correct for the sub - generally installers are pretty good at this, but not every time... How big is your box? the proper box for a 13w3 is either 2.25 or 2.5 cu ft plus the airspace used by the port and subwoofer... With just a rectangular box in my SC, it took up a good portion of the trunk...
http://mobile.jlaudio.com/products_s...p?series_id=26
You can see there that the port is forever long and huge, as is the box...
In my old SC400, I had a 13W1 and output was quite good, even with the fuel tank between the trunk and back seats... sub was facing backwards, as was the port...
No matter what, it will never be as loud as the same setup in a hatchback...
If it were me, I would change the location of the port... Also make sure the port is correct for the sub - generally installers are pretty good at this, but not every time... How big is your box? the proper box for a 13w3 is either 2.25 or 2.5 cu ft plus the airspace used by the port and subwoofer... With just a rectangular box in my SC, it took up a good portion of the trunk...
http://mobile.jlaudio.com/products_s...p?series_id=26
You can see there that the port is forever long and huge, as is the box...
I wonder if it has to do with the port firing into a different air space or if it has to do with the flush panel blocking some of the bass that's created by the actual sub and not the port. Either could be true since moving the box towards the middle of the trunk (ie not porting it directly below the factory sub hole, but rather into the trunk of the car) makes the bass sound 5x louder and deeper.
The reason I ask is the shop is going to have to figure it out. I want to go with the most cost effective fix. Should I take out the flush panel from the box and use the same box or have them rebuild a box? I wonder if they can just move the port on the current box. Do shops typically guarantee against this problem of mine? Will they rebuild a box free of charge?
Or should I just use a completely different box wherein it's longer in depth and narrower in (left to right) width?
Thanks for your advice!
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On a ported enclosure, the port only makes a sound near the enclosures Fb (port's tuning frequency). It doesn't help with any other part of the sub's frequency range.
Here's something I posted a few years ago at Home Theater Forum. The light blue line that peaks at 28hz is the sound coming from the port. As the frequencies increase, the port output decreases and the output from the driver increases. Here's the original thread - link
Here's something I posted a few years ago at Home Theater Forum. The light blue line that peaks at 28hz is the sound coming from the port. As the frequencies increase, the port output decreases and the output from the driver increases. Here's the original thread - link
![](http://static.hometheaterforum.com/imgrepo/d/d6/htf_imgcache_25430.gif)
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On a ported enclosure, the port only makes a sound near the enclosures Fb (port's tuning frequency). It doesn't help with any other part of the sub's frequency range.
Here's something I posted a few years ago at Home Theater Forum. The light blue line that peaks at 28hz is the sound coming from the port. As the frequencies increase, the port output decreases and the output from the driver increases. Here's the original thread - link
![](http://static.hometheaterforum.com/imgrepo/d/d6/htf_imgcache_25430.gif)
Here's something I posted a few years ago at Home Theater Forum. The light blue line that peaks at 28hz is the sound coming from the port. As the frequencies increase, the port output decreases and the output from the driver increases. Here's the original thread - link
![](http://static.hometheaterforum.com/imgrepo/d/d6/htf_imgcache_25430.gif)
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As for the OP's issue, the physical dimensions of the box don't play as much into the it as the reflection off the back of the trunk directly into the woofer will. When you open the trunk, it allows the reflections to have somewhere else to go. It sounds like they built the box with a flat front instead of a slight angle. This can make a HUGE difference in the amount of output you hear due to the fact that the reflection is controlling the woofer to a certain extent. Unfortunately, that may mean having to build a new box. Try this - put a board on the back of the trunk (facing the box) at a slight angle and listen with the trunk closed. If this alleviates the problem, that's your most likely culprit/solution.
Mitsu - the optimum is actually to have the vent on the same face as the woofer in most cases, as it allows the direct control of the vent by the woofer - anytime you introduce a 90 degree angle into it, it can affect the woofer because of the wave interactions. Obviously with transmission line enclosures or obscenely long port sizes, this becomes less of an issue because of the time delay in getting the air out of the vent.
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Big Mack
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I'll try putting a board in the trunk to reflect the bass. If that works, I might just have to build a box with a sub angle slightly tilted upward. I wonder if they can just modify my old box or if they have to start from scratch.
Big Mack, what do you think about just taking off the flush panel to see if that helps allow the air/bass to move into the cabin. This would be the most cost effective since I've already spent a lot on my system.
Big Mack, what do you think about just taking off the flush panel to see if that helps allow the air/bass to move into the cabin. This would be the most cost effective since I've already spent a lot on my system.
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here is what they did to my system. I know that you don't want to redo your system again, but this is just an idea. It was ported and directed to have bass enter the cabin.https://www.clublexus.com/forums/lex...with-pics.html
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Before you start rebuilding everything try a simple test. You stated that the bass was very loud with the trunk open but nonexistent with the trunk closed. Sounds like your sub is 180 degrees out of phase. Try switching the speaker leads on your enclosure (or switch the phasing on your head unit or amp if they offer that selection).
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Before you start rebuilding everything try a simple test. You stated that the bass was very loud with the trunk open but nonexistent with the trunk closed. Sounds like your sub is 180 degrees out of phase. Try switching the speaker leads on your enclosure (or switch the phasing on your head unit or amp if they offer that selection).
#13
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ok time to chime in... what ur dealing with is a standing wave.. causing cancellation.. easiest most reliable way to solve the problem is to load the sub (and port if ur using a vented encl) thru a vent(or slot aka slot loaded enclosure) directly thru the oem sub opening (or armrest but if u have someone sitting the rear seat u'll lose output)an seal the opening to make sure the trunk an cabin are separate.
guaranteed to work 100% of the time
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ok time to chime in... what ur dealing with is a standing wave.. causing cancellation.. easiest most reliable way to solve the problem is to load the sub (and port if ur using a vented encl) thru a vent(or slot aka slot loaded enclosure) directly thru the oem sub opening (or armrest but if u have someone sitting the rear seat u'll lose output)an seal the opening to make sure the trunk an cabin are separate.
guaranteed to work 100% of the time
guaranteed to work 100% of the time
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