People who should know in my area of Philly say I will get the best bass response if I put a sub box in the trunk instead of behind the seats of my roadster. Has anyone tried it both ways?

 

I've definitely heard both and in the trunk is by far the best, especially facing upwards.

 

Actually, I would recommend a downward firing box for a roadster. I had a convertible w/ 2 12's, and it was MUCH cleaner sounding firing downward. If you can find a way, try to port the trunk into the cabin; it makes a world of difference.

 

In the convertible, isn't the trunk separated from the cabin by the roof mechanism? Seems like that could really kill a lot of the output from the sub, so you'd need to compensate somehow. Perhaps like 'Dreams2Reality' said, fire it downward and/or somehow port it into the cabin area.

But I'd say LS350Z is right for a hatchback Z. Firing up or back seems like it would be the best bet.

 

If you have a coupe then the best posible bass and clarity would be in the trunk facing up. You can have an elabortae setup and still not get good sound. Lucky for Z owners, the car is made extremely tight and there is little or no need for dynomat. The reason it sounds best facing up is that the bass reflects from the glass in the hatch and goes forward. It fils the car with a clean and crisp boom everytime. Along these same lines, sound from the tweeters are also better when reflected off the front windshield. Here is a pic of my sub setup:

 

Here is a pic with the neon on

 

Hmm... I might have to disagree here. The Z might be tightly sealed, but there is definitely a need for deadening material in massive quantities. The 350Z has zero sound insulation anywhere behind the seats, so you get a huge amount of road noise when on the freeway. I've owned a lot of different types of cars, and the Z is by far the loudest on the highway just because of road noise. We ended up Dynamatting the doors and all the metal behind the seats. Literally, we took off every single plastic panel from the doors back and covered all the metal with Dynamat.

This isn't just for noise reduction; it's also to prevent resonance in the metal, which is a problem in any car. The more you can deaden all the metal, the better. It really does make a huge difference, especially in any metal that has a bass driver near it or touching it, such as the doors. Most people will have a 6.5" midbass driver pumping out bass in the door, which is basically acting as a big speaker box made of metal. As we all know, metal is probably the absolute worst material to make a speaker box of due to resonance. So the more you can deaden that stuff, the cleaner the bass will be!

 

"If you have a coupe then the best posible bass and clarity would be in the trunk facing up... The reason it sounds best facing up is that the bass reflects from the glass in the hatch and goes forward. It fils the car with a clean and crisp boom everytime."

Bass in non-directional. As long as you don't do anything completely stupid (like face the sub downward without any lift so the cone hits the floor on excursion...i've seen it), you won't notice much difference.

" Lucky for Z owners, the car is made extremely tight and there is little or no need for dynomat."
You WILL need some without a doubt. Maybe less than a civic, but our Z is not exactly a Mercedes when it comes to interior noise. Want proof? Drive over some gravel...

" Along these same lines, sound from the tweeters are also better when reflected off the front windshield."
Definetly a nono. Ideal location for tweets is in kicks. If you don't want kicks, you want the tweets to cross going AWAY from the windshield, not towards. Aiming off the windshield causes reflections of the sound waves, which screws up everything.

Sorry to pick apart, but I am trying to prevent the spread of car audio myths.

 

Bass, like sound is directional and does echo and reflect. Thats basic physics.

"You WILL need some without a doubt. Maybe less than a civic, but our Z is not exactly a Mercedes when it comes to interior noise. Want proof? Drive over some gravel...."[/QUOTE]

I was speaking of vibrating due to bass notes not highway driving. There is absolutely no dynomat in my car and absolutely no trunk rattle, no licence plate rattle, no door rattle of any kind due to the bass. As for driving on gravel, not recomended. thats what trucks are for, I bought a Z to drive on the paved roads.

" Along these same lines, sound from the tweeters are also better when reflected off the front windshield."
Definetly a nono. Ideal location for tweets is in kicks. If you don't want kicks, you want the tweets to cross going AWAY from the windshield, not towards. Aiming off the windshield causes reflections of the sound waves, which screws up everything."[/QUOTE]

Again, no car sterao myth. Sound reflects, ever been to the grand canyon. Say "HELLO!!!!!" You will hear it several times, you know why, ECHO. If you want to argue with the engineers that made the Focal tweeters, go right ahead. I think they have plenty more experience than you, me, and most other people and i have been involved in audio systems for 10 yrs now. And to let you know - earlier you said sound is not directional and then you say it reflects, contridicting yourself there a little - But like anything - forums are to discuss opinions and share ideas - thanks for not bashing and stating your opinions and beliefs - thats what makes this forum good - you say what u know i say what i know and someone else will say something else - all i know is my system sounds off the hook, i'm sure yours does to - we do what works for us

 

Definitely firing upwards in the trunk.. like this..

 

Dream2,

I agree with you on most of your points except the "bass is non-directional"...

While its true bass is omnidirectional (its the more "positive" way of saying the exact same thing ), bass still adheres to the acoustics of a volume. In home audio, for instance, if you put your sub in just the wrong place in your room, you'll get all kinds of reflections which will completely distort your sound (oftentimes the result is when a certain freq' plays, the bass seems to all of a sudden double in power). . .

To maximize the volume of your vehicle as an acoustic "chamber" - place your subs facing a direction that they can reflect and amplify. Want proof? Try it with any sub box. Place it in the trunk facing forward. Listen for a moment, both inside and outside your car. Then, turn it around and face it towards the rear. It will be louder.

 

Quick responses to you guys:

1) Focal's demo car uses kicks, so I'm not exactly arguing against them.
2) Please explain this "echo" theory...it's interesting, but not sure that it matters being that it's in car.
3) Subbass (40-50hz or so and lower) is omnidirectional. Anything higher (IMO) should be played through your front speakers, and in turn pull your soundstage forward. Different soundwaves act differently. Also, being directional is not the same as being able to be cancelled or reflecting. All that matters is what you hear, and what you HEAR from a properly installed system is directionally influenced by your front speakers, with the sub more used for "impact" than sound. In a great car, you can't even tell the subs are off when the fronts are pumpin.
4) While moving the box around may reduce cancellation, there's no magical way to put a box that will make an enormous difference.
5) Your Z NEVER drove over a little dirt or broken up street? You are one lucky guy. In the joys of post-winter NJ, there's tiny bits of salt, sand, and asphalt all over the place. Drive over it (I'm not talking about off-roading) and you WILL hear what sounds like rocks in a can being shaken; louder than any other car I've been in.

but as you said, you enjoy your system, and I'll enjoy mine

 

Quick responses to you guys:

1) Focal's demo car uses kicks, so I'm not exactly arguing against them.
2) Please explain this "echo" theory...it's interesting, but not sure that it matters being that it's in car.
3) Subbass (40-50hz or so and lower) is omnidirectional. Anything higher (IMO) should be played through your front speakers, and in turn pull your soundstage forward. Different soundwaves act differently. Also, being directional is not the same as being able to be cancelled or reflecting. All that matters is what you hear, and what you HEAR from a properly installed system is directionally influenced by your front speakers, with the sub more used for "impact" than sound. In a great car, you can't even tell the subs are off when the fronts are pumpin.
4) While moving the box around may reduce cancellation, there's no magical way to put a box that will make an enormous difference.
5) Your Z NEVER drove over a little dirt or broken up street? You are one lucky guy. In the joys of post-winter NJ, there's tiny bits of salt, sand, and asphalt all over the place. Drive over it (I'm not talking about off-roading) and you WILL hear what sounds like rocks in a can being shaken; louder than any other car I've been in.

but as you said, you enjoy your system, and I'll enjoy mine

 

I'll agree with you that I don't have any rattles of that sort either. The car seems pretty solid. (I might feel differently in 50k miles, but for now it's great.)

When I recommended deadening material, I was recommending it primarily to reduce resonance in the metal. I believe this can benefit any car, especially when you are installing a bass driver directly into metal parts. (Such as in the door of the Z.) If you look at home speakers (and sub boxes, etc.) they are always enclosed in wood since wood dampens the resonance very well. A metal door, though, won't dampen it at all, thus the benefit of deadening material.

I have to admit, I just installed almost 70 square feet of Brown Bread in my car (entire metal surface from the seats back, and the entire doors) and it didn't seem to drop the cabin noise by much. But, the car sure is "dead" now, and the bass, especially from the 7" Dynaudios in my doors, does sound noticeably "cleaner" (for lack of a better term).

 

you'll get better sound if you put the subs under the strut bar facing the back of the car. when the sound waves reflect off of the back of the trunk and move to the front of the car...the waves will be full. you'll get better sound doing that rather than facing them up.