mcamson

That would require me to spend another $250 to build a new box. I took it back to the shop today and they helped increase the bass by changing the sub output frequency on the amp. It was originally set to 70hz and they upped it to 100hz. It sounds a bit better now as it wasn't properly tuned with the box originally.

mcamson

How would sealing the stock subwoofer hole solve the problem? Are you saying the interior speakers are canceling the sub?

excluesive

iTrader: (10)

this is interesting.. keep it going.

lev00221

iTrader: (28)

No. You are getting a direct wave from the sub (and port) into the cabin as well as reflected waves bouncing off the trunk walls and then going into the cabin. If timed properly they will cancel each other and negate much of the bass that you hear (feel) in the cabin.

I had similar issues in an Acura TL.........sealing the rear deck fixed the problem.

Big Mack

iTrader: (1)

They may be able to modify it - but it shouldn't be on your dime, and if they can't modify it, a new box shouldn't be on your dime, either, IMO.

It can't hurt to try, since it costs nothing to do so. You may even use this panel to bounce the wave around as I suggested before.

Hmmmm...very difficult for this to be a standing wave, given the fact that at 40 Hz, the wave is about 28 feet long (they get shorter as the frequencies increase). After re-reading your post, I questioned whether or not a wave interaction between the subs and the air coming out of vent, but don't think that it will really come into play due to the change you describe with the trunk open. I really do think it's the wave bouncing back toward the woofers directly, but the distance between them probably isn't an exact harmonic of the original wave, so the interaction between them shouldn't completely negate it, but this is not the same thing as a standing wave, which requires it to be an almost perfectly square environment, which we know a car isn't.



Here's the issue - the vent is 90° offset from the sub. It will, therefore, have a wave heading into the cabin at a different time than the sub will, and that timing would be almost impossible to do accidentally. Possible? Yes. Plausible, not in my experience. I'm sticking with the bounce from the trunk negating the output from the subs themselves, and he's hearing mostly the output from the vent.

I'm concerned that the shop increased the crossover point on the amp as a way to mediate your concern. Unless your front stage is tiny, you really should try to keep subs playing as low as possible to achieve the illusion of bass up front and keep the subs from drawing the stage toward the trunk.

Let us know how things are coming along and if the ideas work.

Big Mack

Shibumi1

depending on which way the port is facing all u need to do is add a slot to the existing enclosure in front of the cone of the woofer (about 2 to 3 inches from the cone 2" wider than the woofer diameter run it from floor to ceiling an flush it to the opening where the oem sub opening) seal the slot to ensure all the output enters the passenger compartment... an done... shouldn't run $250...

depending on the size of the encl u could just seal the port if its not able to be added to the slot

mcamson

The port is facing upward facing the stock subwoofer hole. I'm not sure I understand your recommendation. What do you mean by adding a slot. Do you mind drawing an example in paint? Thanks.

Shibumi1

discussed all this in a different thread.. take a look at this maybe it will clear things up a bit


https://www.clublexus.com/forums/ls4...premium-5.html

305Busa

Im thinking that I had the same issue youre having and what was done a few days ago really increased the bass output intot he car. I have a 12" L7 facing the rear of the car with a beauty board but its a sealed enclosure and its driven by a ZX750.1. It sounded and looked good but I knew it had a lot more. I dont have pics of the new set up but what was done was something borrowed from another site which I'll post up as well. We took the beauty board and but ovals on the sides as far out as possible, then covered the ovals with mesh and painted them black. This allows the bass thats trapped in the trunk to be able to vent into the inside of the car thru the factory sub opening. This install is in an LS so Im pretty sure the trunk is just as sealed from the cabin as yours. Pics and links below.

http://www.netaudiowf.com/garage/cus...alls/lexus-l7/

mcamson

Thank you for your recommendation. Now we're getting somewhere. I expected to see more people on this message board that experienced this same problem. I'm assuming the holes that you cut out are on the part of the flush panel sides and not the part that would make a hole in the actual subwoofer box right? Sorry if that is a stupid question. I just want to be sure.

Do you think that would solve my problem though? My shop designed the box so that the bass created by the subwoofer cone (as opposed to the bass created by the port) travels from the trunk to the subwoofer hole by leaving about 3-4 inches off the top of the flush panel.

Do you have pics of your setup that illustrate where you put the holes?

305Busa

Correct, the holes are in the beauty board and not the box. The beauty board was actually creating an almost perfect seal between the trunk and the cabin, as if isnt sealed enough. It sounded good but when we tested with and without the board, it was a lot louder without. As I stated, I have a sealed box because I didnt want to use up much room so its a little different than yours but Im sure the concept is the same. I'll take pics of the new set up when I get a chance and post them.