# sealed trunk blocks bass



## shapiro (Feb 15, 2012)

My trunk isn't completely sealed from the cabin but pretty close. If I fold the seats down there is A LOT more road noise, and the bass is A LOT better (if parked with no road noise). Is there anything I can do to get more bass to my cabin? 

I obviously haven't deadened anything yet but have the materials on the way... should be done in a couple weeks. I imagine this will help it by keeping the bass in. What else can I do?


----------



## cruzinbill (Jul 15, 2011)

you could always go IB


----------



## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Your fold down seat is hard-backed.... remove the backing... 

Remove rear speakers, vent trunk into cabin... 

Leave the seats down... 

Get more bass...

Bout it...


----------



## Spyke (Apr 20, 2012)

Aaron'z 2.5RS/WRX said:


> Your fold down seat is hard-backed.... remove the backing...
> 
> *Remove rear speakers, vent trunk into cabin... *
> 
> ...


I'll agree with this one. I have a bmw e36 which are terrible for bass. The trunk is very deadened to keep road noise down. The rear speakers have plastic enclosures which need to be removed also. Made a huge improvement.


----------



## KSpan (Mar 9, 2012)

Could always cut a port in your rear deck - would be hidden under the overlay and, if done neatly and properly, most people would never know it wasn't stock.


----------



## maxxx (Feb 4, 2009)

I imagine it depends on the car, but I would think a sealed trunk is an opportunity to use it as an enclosure (in an infinite baffle sense). You could put a large array of 6 or 8" drivers across the rear shelf, or if you don't want that extent of customization you could use compound 6" or 8" drivers (2 each for min. +3dB) firing through the factory rear speaker holes.

Fairly common is just firing a 15" or 18" driver at the back seats from behind, no enclosure, fairly sealed trunk (some lossiness is no big deal). I have heard setups like this that provide more than impressive bass; a driver that big can move a lot of air at low frequencies, even through the seats.

...or some combo of the above! GL


----------



## shapiro (Feb 15, 2012)

Thanks for the responses. There are no rear speakers so that option is out. I'm a little scared to vent the trunk in case it adds a lot of road noise as well. I have already been considering going IB... I don't have a lot of power, and I have a HUGE rear deck anyway, I'm pretty sure I could a fit 15" in there. One thing is I have never heard it before and am a little nervous cutting up the rear deck...What if I hate the sound of IB?


----------



## Aaron'z 2.5RS/WRX (Oct 24, 2007)

shapiro said:


> Thanks for the responses. There are no rear speakers so that option is out. I'm a little scared to vent the trunk in case it adds a lot of road noise as well. I have already been considering going IB... I don't have a lot of power, and I have a HUGE rear deck anyway, I'm pretty sure I could a fit 15" in there. One thing is I have never heard it before and am a little nervous cutting up the rear deck...What if I hate the sound of IB?


You don't have ANY holes through the rear deck? 

How about those seatbacks? 

you could try IB by pulling the back seat and building a baffle... 

Other things can be done, but that'll be the cheapest/easiest..


----------



## nosaj122081 (Apr 7, 2012)

If you do a nice, clean job of cutting out the steel outta the deck, save it and you could always weld it back in... Even if you can't weld, I can't imagine someone would charge you a whole lot to do it, not a complicated welding job nor would it take a real long time. I wouldn't think more than $50 (if you did the prep).


----------



## Rudeboy (Oct 16, 2005)

shapiro said:


> Thanks for the responses. There are no rear speakers so that option is out. I'm a little scared to vent the trunk in case it adds a lot of road noise as well. I have already been considering going IB... I don't have a lot of power, and I have a HUGE rear deck anyway, I'm pretty sure I could a fit 15" in there. One thing is I have never heard it before and am a little nervous cutting up the rear deck...What if I hate the sound of IB?


What do you want your bass to sound like? If you want a box you could mount it to the rear deck from underneath. Not having your sub's cone sharing airspace with the passenger compartment in a car with a trunk is like putting your home theater sub in your neighbor's house.


----------



## Spyke (Apr 20, 2012)

Let's start over. What kind of car? What kind of sub and amp? What is your sub orientation (which way is it facing)? Have you tried switching phase? For all we know you have a 6" subwoofer running off of your hu.


----------



## doubledown77 (Apr 2, 2012)

^^^what he said, sub orientation alone could probably be your fix, but without knowing the specs of what your running kinda hard to say:afro:


----------



## shapiro (Feb 15, 2012)

Rudeboy said:


> What do you want your bass to sound like? If you want a box you could mount it to the rear deck from underneath. Not having your sub's cone sharing airspace with the passenger compartment in a car with a trunk is like putting your home theater sub in your neighbor's house.


I don't want real loud bass, more interested in SQ. I like a hard kick drum, and heavier low end bass. Not really sure how else to describe it...


----------



## shapiro (Feb 15, 2012)

Spyke said:


> Let's start over. What kind of car? What kind of sub and amp? What is your sub orientation (which way is it facing)? Have you tried switching phase? For all we know you have a 6" subwoofer running off of your hu.


The car is a 2012 Passat. The amp is a BA GT-475 (two channels to mids, bridged channels to sub at 250W) The sub is a BA G110-44 10" in a small sealed box. I tried different orientations with it, I settle on it facing the rear. I tried switching phase, it didn't help. I know it's not a setup for tons of bass or anything but there is a huge difference just by dropping the rear seat.


----------



## Rudeboy (Oct 16, 2005)

That makes the problem pretty clear - your trunk is a bass trap. Drop the rear seat backs and your problem is solved. Move the enclosure into the passenger compartment and I'll bet it will be great. A bass trap trunk makes IB easy but mounting the box under the rear deck is another possibility. I'm more surprised that an enclosure in a trunk meets some people's expectations than I am that it disappoints others. There are a bunch of reasons not to do it.


----------



## indytrucks (Apr 5, 2009)

I'm in the same boat to an extent. My cars back seats don't fold down though. I took the factory sub that was in an IB configuration in the rear deck out and plan on doing a fourth order with the port coming through the factory subs location. Plus side- no trunk rattle. Negative side- limited sub freq. band. Tuning the port over time will yield optimal results I suppose.


----------



## Aaron'z 2.5RS/WRX (Oct 24, 2007)

indytrucks said:


> I'm in the same boat to an extent. My cars back seats don't fold down though. I took the factory sub that was in an IB configuration in the rear deck out and plan on doing a fourth order with the port coming through the factory subs location. Plus side- no trunk rattle. Negative side- limited sub freq. band. Tuning the port over time will yield optimal results I suppose.


Or you could mount IB subs below the deck the hole on a baffle and create a blow-through... works just fine.. 

None of that forth order crazzap


----------



## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Rudeboy said:


> That makes the problem pretty clear - your trunk is a bass trap. Drop the rear seat backs and your problem is solved. Move the enclosure into the passenger compartment and I'll bet it will be great. A bass trap trunk makes IB easy but mounting the box under the rear deck is another possibility. I'm more surprised that an enclosure in a trunk meets some people's expectations than I am that it disappoints others. There are a bunch of reasons not to do it.


 
Which is why I mentioned removing the hardback from the seats... which I think went' unnoticed..


----------



## shapiro (Feb 15, 2012)

Aaron'z 2.5RS/WRX said:


> Which is why I mentioned removing the hardback from the seats... which I think went' unnoticed..


I noticed it before and am considering it as an option, just forgot to comment on it. 

Right now I'm leaning towards just going IB. Everyone says the SQ is better with it anyway, and I'm sure having the sub in the cabin is going to make it hit harder than how it is.... win win.


----------



## Victor_inox (Apr 27, 2012)

forgive my ignorance, what is IB?


----------



## shapiro (Feb 15, 2012)

IB=Infinite Baffle. Rather than putting the sub in a box, the idea in this case is using the whole trunk as a box. Because the volume of air is so large it's essentially like mounting the sub in no box... or something like that. Since the rear deck in my car is huge, I would just mount the sub (or subs) there, and make sure the cabin is completely sealed from the trunk... as well as making sure the trunk is sound deadened quite well so it doesn't rattle.


----------



## Victor_inox (Apr 27, 2012)

Cool, thanks, of course I know what infinite baffle is.


----------



## Spyke (Apr 20, 2012)

Yes. You can get some seriously low freq from ib. As long as you don't mind some modification to your interior it's the way to go. Be careful with sunlight on that back deck though. It'll destroy speakers. Maybe some kind of cloth over it or I think you can get uv treated speakers. Just a thought.


----------



## shapiro (Feb 15, 2012)

Spyke said:


> Yes. You can get some seriously low freq from ib. As long as you don't mind some modification to your interior it's the way to go. Be careful with sunlight on that back deck though. It'll destroy speakers. Maybe some kind of cloth over it or I think you can get uv treated speakers. Just a thought.


Thanks for the tip. I've been shopping a little for one with UV treating... it looks like all the marine audio subs are UV treated, which might be the way to go, but they are pricey and I can't find one in 15" yet. Would it protect it enough if I just wrapped a piece of cloth under the grilles? 

Anyone have any good suggestions on 15" IB sub? I don't know anything about what to look for with IB yet (haven't really started the research). I have 250W @ 2 Ohms, or if I have to 200W @ 4 Ohms. I would like 1 2 ohm sub if possible to save money, but am willing to get 2 4 ohms if needed.


----------

