Door speaker install question

OK, so the OEM speakers have this gasket kind of arrangement that fits up to the interior door panel.

Most everyone I've ever seen installs aftermarket speakers with no effort to replicate the foam gasket.

On my MR2 I used some closed cell foam around a set of the Pioneer Premier PRS components and was impressed with bass output; however, I never did an A/B comparison of with/without.

With absolutely no evidence to support my idea, I 'think' the foam would help control/eliminate stray sound waves bouncing around between the inner metal door skin and the interior door panel.

Anybody have any objective tests they have witnessed, or have some science into why it would/wouldn't matter.

I ask mostly because when I installed my speakers I knew I would be swapping components in/out. Now that I've settled on Seas speakers, I'm wondering if it's worth taking off the panels and making up a gasket set.

Not that it probably matters, but my baffle plates are 1" thick King Starboard material, and the doors are relatively well damped and then covered in some neoprene. Offered since my first comment back to this sort of post would have been - "well, have you put any damping material in there first?"

 

You're on the right track! . Speakers emit sound from the back of the cone as well as the front of the cone and the factory must know that the rear sound wave interacting with the front sound wave can cause cancellation so they seal the speaker to the door panel since there are a bunch of holes in the inner door frame. When people deaden their doors properly they will cover up the holes (especially those close to the speaker) and this will give the same effect as sealing the baffle to the inner door panel (I think I posted more about this in my TUTORIAL HERE or maybe on the FAQ sticky at the top of the page). If I can find it I'll post a link to a thread I made a while back on another forum showing the numbers on an RTA which revealed a great increase in lower freq output with the sealed speaker and in any case it was very easy to hear the difference which is most important IMO.

 

I didn't do any objective testing but I also used a gasket of CCF on the back of the door brackets I got from Marv along with some foam weatherstripping between the speaker and the bracket itself. Seemed like that made a really good seal. Also used ItalynStalyn's method of plexiglass over the two large holes along with sealing all other small holes with deadener. I think overall it made a very nice baffle and the bass response from the fronts alone is very impressive.

If you're going to do anything might as well do it proper, huh? I say make the the proper sealed baffle.

 

First, thanks for the reply(s) and thoughts expressed. And just so it's clear, I do have all the door openings sealed, so I'm not getting cancellation from the rear of the cone.

I was asking if anybody thought there was a difference due to the wave off the front of the speaker hitting parts of the back of the door panel and then bouncing back to interfer with the following cone movement.

 

I see what you mean now. There probably is a physical difference because some waves will hit the door panel and reflect back but whether or not that constructive/destructive interference is audible is going to be dependent on tons of factors not limited to source, driver, baffle, mount angle, etc. Very hard to objectively measure. I didn't try to seal the front of the baffle to the back of the door panel. I thought that the thin material of the door panel will probably not cause enough reflection and interference to make any difference to my ears.

 

Looks like I misread what you were asking! As mentioned there would be lots of variables and even though it's a good bet you could measure a difference, hearing a difference in your specific application is something that could really only be determined for sure in a blind test since "test gear can measure everything our ears can hear however our ears cannot hear everything test gear can measure".

 

Well, I asked Santa for a new laptop; however, not sure if the Jolly Old Elf (actually SWMBO) has enough coin this year.

But if it happens, and I can find some time, I'll get TrueRTA running again and check the numbers before and after. The plan being to put a ring of some closed cell foam surrounding the 6.5" speaker, extending out to seal up against the 6X9 ridge in the door panel to which the OEM speaker mated.