if your car is not very airtight, do you loose a lot of SPL? i've read somehwere a good way to improve your SPL score is to have an airtight as possible car..

if anyones seen my rattly sliding windows, they will know that they arent very air tight, (and are quite embarressing cos they rattle a lot :red: )

so am i loosing some SPL? i know im loosing a lot due to a big cabin(you dont feel the pressure on your eardrums like you do in a smaller car :( )

as a guess i would say your right

would explain why the big time SPL cars have their doors screwed shut

and an airtight vehicle would hold a better (Sub) Pressure Level :)

I suppose the less vibrations and leaks the better hence the sound proofing and reinforcing but I'm just guessing

but when you open a door sometimes the spl goes up ;) ....

interesting discussion..i'll put it down to trial and error !

I would like the chance to experience a full on SPL car

but when you open a door sometimes the spl goes up ;) ....

good point G, like team gates bronco when it had the kicker gear in (not sure if its changed installs lately?) ... :)

interesting, do you need to design a system to be louder when the door opens or does it just happen by chance sometimes?

but when you open a door sometimes the spl goes up ;) ....

interesting discussion..i'll put it down to trial and error !

but isnt that because the door acts like a port or something? turning the car into a bandpass box ?:) GULA's car is like that! its quite mental..

but i mean just pressure leaks? like bad door seals, not open windows etc ? :) or would it just be the same thing?

Ill put it down to a combination of things ;)

Some cars gain with the door open, others dont. That I can only guess at reasons for.

As for small holes tiny air leaks etc, I wouldnt worry too much, I can tell you a few UK cars that lose dB when the doors are held shut ;)

The Vovlo has bolt holes in the floor for the bucket seats. Sometimes we plugged them, other times we didnt, no diference in scores either way.

Vibration is a big thing though. Some vibration gains dB, some vibration loses dB. This is diferent from car to car and is only solved by lots and lots of testing.

Not all extreme cars bolt the doors shut ;) And some only do it to stop the doors being blown off LOL

Ben

Not all extreme cars bolt the doors shut ;) And some only do it to stop the doors being blown off LOL
Ben

:eek: didnt know that, i thought that the only reason the doors were bolted was to stop the unwanted vibration

just out of interest ever seen anything like that happen?

I remember that movie of the that American van and the Brahma that cracked the door, I just can't imagine how powerful that would feel

good point G, like team gates bronco when it had the kicker gear in (not sure if its changed installs lately?) ... :)

interesting, do you need to design a system to be louder when the door opens or does it just happen by chance sometimes?

The original Bronco had the doors held shut by a vacuum seal arrangement;)

AFAIK there is a new Bronco being built, number 3 i think? Number 2 was JBL, number 3 is RF IIRC.

Ben

:eek: didnt know that, i thought that the only reason the doors were bolted was to stop the unwanted vibration

just out of interest ever seen anything like that happen?

Havnt seen it happen yet.

Just out of interest I did see the Timanji burping at the Euros with no bolts in the doors, burping at 1/4 actual volume and still doing 167s LOL

Just proves exactly how much extra power you need to get to 170+

Ben

hmmm... wouldnt mind a crack at this SPL business

would mean i'd have to get a box design with a port plug though, mind you i dont have a streetbass box design for the sub that i havent bought yet, so i guess it wouldnt take much to alter the plans :lol:

167 @ a 1/4 volume :wow:

couldn't get anywhere near that flat out :lol:

Also the same car with different installs can lose/gain at different times from door vibration. Just to confuse matters even more!

Ray Harvey's Beemer with doors closed 157odd
with one door open playiig bass cd's 162-163 odd

It seems to me that the lower tuned/StreetBass set up are louder with 1 door open and the opposite seems to be true for a high tuned/spl set up .

But to be honest it is really down to testing and trail and error.Having use of a a mic is a great help.

My SBL wagon is having tha port tuned with one door open as when i am at shows this is how it will be played.

Is it because the bass is 'free flowing' making it louder, instead of having massive amounts of pressure build up?..

try blasting your system for around 2-4 mins with the windows up, then on a heavy bass tune turn the window down & listen to difference :clown:

Id suppose it depends on the mics aswell.

New mics may read differently with the doors open, they read in a different way to the "other" mics.

You can blow on the new ones and read no score ;)

Ben

dont the new mics register the air pressure? which is why i would have thought a more airtight car would be better?

They are more air pressure related than the old ones I believe.

Cant really say too much cos I have limited experience of them.

The old ones were more of a microphone and were responsive to movement rather than pressure I believe.

Ben