Trunk open or closed????

Kenny and myself just fineshed a new set-up for his trunk car. We noticed it sounds quite a bit louder with the trunk open. We dont have a TL so we are not sure. (You know how it is when you think ya got louder and ya didnt). I have never seen anyone run with their trunk open. I guess my ??? is.....is it possible to be louder with trunk open?

Yes it is.. I have witnessed someone gain after opening there trunk. Only way to tell is try it. you get two runs. lol

with the setup changing we are not sure his freq. so we have to run the slope to see....I think we are going to do it with the trunk open and on the second run fan it while he is burping

he also runs SB2. do you think it would also effect SB?

Possible, might lose or might not.. again that is something you have to test and find out.. run the sweep on the first run with trunk closed.. see where it peaks and wait for the second run.. burp at the peak with it closed, wait 5 seconds and burp with it open.. should get an idea if it works

which way is the box facing? My current box for a single 15 MT is forward firing and at my last show i got a 143.0 trunk closed @ 54hz (loudest freq with the trunk closed) so i decided to try a rerun trunk open at tuning freq (45hz) and hit a 146.5

i was surprised at the difference

Edit: added tuning freq

well emperor it is really wierd set-up....it is in a honda accord 87 or 88...we built a tub that takes up most of the trunk(we had to take both front seats out and the door off the hinge to get it in and slide it back into the trunk). Inside the tub we have a box with the speaker and slot port facing the back of the car...the box is to left side of tub with a 10 inch gap or so on drivers side to let the air and noise into the vehicle.

I know...I know...wierd huh?

ya just a lil... why did u need to build a tub?

and you shouldnt gain by opening the trunk

the idea of the tub was to try to narrow down the air space in the car. I did not think it should be louder either but you can tell a diff. not only in the amount of air movement, but also pressure and sound.

So far his top score is 146 with one JLw713.5 in stock 0-600. hopefully tomorrow we can beat that.

cfriesz wrote:

So far his top score is 146 with one JLw713.5 in stock 0-600. hopefully tomorrow we can beat that.

How are you in stock of you had to take the seats out?

And yes that is a weird design.....shoulda just used the tube as an enclosure

All seats are back in and so on.. all back to stock .

Sounds like a bp setup in a way.

Moparbass28 wrote:

All seats are back in and so on.. all back to stock .

Sounds like a bp setup in a way.

Correct we put everything back in to get back to stock....we did try using the tub for box but he just made a board with a hole I tried to tell him it needs an actual port but it sounded so bad he wont even try it again and what is a bp setup....Bandpass?????

yep.. bandpass

I've also seen cars gain by opening the trunk. Sometimes it will allow cancelation to correct itself. Just like opening the window or door up front does. It turns the car itself into a bandpass enclosure of sorts.

You know I wondered why it made such a diff.....I mean the door open thing......would have never guessed the trunk though

well its off to comp....I will let you guys know how much of a diff. (if any) that it makes

cfriesz wrote:

well its off to comp....I will let you guys know how much of a diff. (if any) that it makes

hope you didn't leave already, the single pointer starts at like 6pm tonight

Thanks man I was just about to leave.....guess I would have been sitting there for awhile huh???

Is ur box facing forward?

And is that allowed in stock classes to open the trunk?

Yes opening the trunk is allowed. Just like opening the door.

Skip01 wrote:

Is ur box facing forward?

And is that allowed in stock classes to open the trunk?

the open side of the tub is facing forward but the box inside the sub and port are both facing to the back. and yes Mopar is right yet again it is allowed to have trunk open just never seen anyone do it.

its a 10 dollar test if you dont know ur tone... if you do its free

Moparbass28 wrote:

Yes opening the trunk is allowed. Just like opening the door.

In stock class?

Never knew that

yep.. in stock ..

yup i ran the trunk open in the stock class

I may have to try it, think if memory serves me right I lost opening the trunk. Then again my memory sucks anyways, so I will test today and see. LMAO

Hey guys breaking news from the l&c show.......Kenny did hit 2.3db higher with trunk open although his score dropped from his best with this setup it was still louder open...did not try it with it closed in SB.

gj glad you tried it then no?