Should the air behind a speaker (Lucid panels w/ Kenwood in this case) go into the trunk? Into the cabin? All of the above?

Reason I ask is after installing some sound deadener I could swear the speakers make much less bass . I more or less sealed the trunk from "venting" into the cabin to cut down on noise, and I am wondering if this is bad for speaker performance.

I checked the wiring and looks like it's all ok (can't really mess it up with the Lucid Harness )

Help and info will be appreciated.

 

It kind of depends...by sealing off the trunk, you have effectively changed the air volume the speaker has to work with. It may help you in some cases, and in others it may hinder you. This is the reason so many calculations go into the creation of a sub box. If you notice a significantly less amount of bass, you have probably hindered things...the speaker isn't hurt, it just isn't able to give you its all.

 

Alright, so if I open up an airway to the trunk would I expect an improvment? Mind you these are fairly small speakers.

This whole Audio thing if fairly Greek to me.

 

Well, you're starting to mix a buch of stuff up at once.

Subs depend heavily upon their air volume. It sounds like you aren't using one of those, though. If you are, opening things back up shoudl give you the original sound.

If we're talking midranges and the sound changed, the bass you heard before the sound deadener may have been something else in the car resonating at a lower frequency (bass), but it has disappeared now that you've deadened it.

 

Nope all OEM except for the rear speakers.

Your explanation makes sence and the improved noise reduction from the damper is worth it.

I notice that the bass in the trunk is more pronounced than in the cabin. When I poked holes from behind the speakers to the trunk a bit more was noticed. Oh well, don't think I will change it and the fronts sound just fine if not better now.

 

When you added the deadener, did you disconnect the speakers? If so, check your phasing.

 

Where did you add the sound barrier? Behind the speakers? Or did you seal around the speaker panel itself?

It sounds like you added the sound barrier behind the speakers, which has effectively reduced the speaker cabinet volume, and at the same time caused more sound to be reflected back to the speaker panel which may be cancelling some of the bass.

If you can get the same effect by putting the sound barrier on the speaker baffle (in this case the rear panels) and remove the barrier you installed behind the speakers you should get the opposite effect - more bass than you originally had. Anything you can do to seal off the back of the speaker from the front will improve the bass.

It may also be a benefit to add some sound-absorbing material behind the speakers to reduce reflections from the metal surfaces back there. Poly fill (like for stuffing pillows) is inexpensive and works well. There are special speaker filling materials you can buy that are better but they are significantly more expensive and probably not worth it in this type application.

One more thing you should be aware of - by sealing off behind the speakers (or sealing the speaker panel as I suggested) you are interfering with the flow-through ventilation system in the car. It may not be a big deal but I think you should be aware of it.

All cars have this system, which is in place to make sure the cabin stays ventilated and can't build up exhaust fumes (in case of an exhaust leak). The cabin vents through those rear panels, which vent into the trunk, which vents through a one-way flapper to the area behind the rear bumper. The system is designed so that even if the fan is off and the windows are closed, higher air pressure at the base of the windshield forces are into the cabin and it flows through to the low-pressure area behind the bumper. By sealing off the rear panels you might stop most of that air flow.

 

Modifry

I "think" I get what you are saying, let me explain exactly what I did.

I used a Dynamat type product in the cavity behind the speaker magnet. This product is quite thin so I don't think that the cabinet volume is reduced. Then used a decoupler in the area next to it that goes into the trunk, effectivly creating a "wall" between the cabin and trunk (this may be what you mean by reducing the cabinet volume??) so the vent in the speaker pannel really can only vent the speaker itself. In an unscientific sort of way, I put my hand over the vent while the speakers were in use and didn't feel any air movement, so I wasn't sure if sealing these would change anything.

The part about the polyfill is a good idea and I may try that.

Are you suggesting to put the damper material (Dynamat like stuff) on the back of the speaker pannel itself?

Thanks for your help guys

 

If you used car audio speakers (and why wouldn't you? ), then you probably would be better off giving them the more airspace.

Car audio speakers are designed (or selected?) to be mounted Infinite Baffle--meaning it's got a rear enclosure bigger than the Vas of the speaker...The speaker will have a stiffer suspension to make up for the lack of an enclosure pushing back against the speaker...

So uh...yeah...I wouldn't seal off the back otherwise you run into one of the problems that always comes about from having drivers in too small enclosures--limited extension