How To Make your system BUMP
Or are you doing SPL competitions?
It helps a lot. More than I expected.
Also, If you get rear ended hard enough to reach the gas tank(directly behind the back seat) you're pretty screwed anyway. there are plenty of places for fire to enter the cabin...removing the plate wont make a difference.
I was running 4 tens and over 2k watts, so I ported thru the rear deck as well.
this is an old pic from 2000-2001. It hasnt changed much, but u get the idea
Also, If you get rear ended hard enough to reach the gas tank(directly behind the back seat) you're pretty screwed anyway. there are plenty of places for fire to enter the cabin...removing the plate wont make a difference.
I was running 4 tens and over 2k watts, so I ported thru the rear deck as well.
this is an old pic from 2000-2001. It hasnt changed much, but u get the idea
Air exchange is all that matters in bass reproduction. All I can assume is that it is allowing more air to leak around the seat somehow. Simply removing the factory sub an an SC model provides 9 inches of port which will provide ample air exchange. I dunno about other models, but most all Lexus are leather interiors and no subs will broadcast through leather because it is air tight. That's all a sub does, move air
Resonance is a negative in the car, not a positive. That's why we spend $400 on dynamat.
Air exchange is all that matters in bass reproduction. All I can assume is that it is allowing more air to leak around the seat somehow. Simply removing the factory sub an an SC model provides 9 inches of port which will provide ample air exchange. I dunno about other models, but most all Lexus are leather interiors and no subs will broadcast through leather because it is air tight. That's all a sub does, move air
Air exchange is all that matters in bass reproduction. All I can assume is that it is allowing more air to leak around the seat somehow. Simply removing the factory sub an an SC model provides 9 inches of port which will provide ample air exchange. I dunno about other models, but most all Lexus are leather interiors and no subs will broadcast through leather because it is air tight. That's all a sub does, move air
Bass, or any audio, for that matter, does not just move air... The woofer moves air as part of its suspension, however, soundwaves are independent of air travel, and will in fact travel through anything that is capable of resonating or vibrating...
Want an advanced, yet easy test to prove my theory? put a small boombox / clock radio / whatever into a sealed container, such as an ice chest... make sure it seals well, and turn it on, loud... close the lid... - can you hear it? of course you can... the sound waves simply bounce around inside, and when they hit the wall of the container, that material resonates or vibrates, passing the energy through it to the air outside...
In all honesty, air is a horrible conductor of sound waves... sound waves travel MUCH faster through solids, and travel faster through most liquids as well...
oh, and one more thing..... the reason we use dynomat is to dampen those unwanted resonances... different materials have different resonant frequencies - it has to do with their mass and construction, as well as material... The reason we use dynomat, is to add mass to these materials that are resonating (Causing unwanted peaks in the audible spectrum) in an effort to bring their resonance frequency below what the human can hear...
while I'm on this same theory, just the other day, I was retuning the amp and EQ in my car... my chick comes outside and says, "thats a lot louder than it was" as something inside the house was shaking almost violently... inside the car, it was no louder, but the music I was playing obviously had a note in it that carried from the driveway into the house on the second floor, and was at the exact resonant frequency of the thing that was shaking (a table lamp)... it wasn't the air that was making it shake, it was the soundwaves traveling...
a side impact to the back quarter panel could easily cause gasoline to leak everywhere inside the cabin if this plate is not in place...
at the same time, it's like having a fire retardant suit on while racing... if the car catches fire, you will most likely catch fire, however, that fire suit will give you X amount of minutes worth of survival time... that plate is there for the same reason... its not that it will entirely prevent fire or explosion from entering the cabin, but it will definitely slow it down...
this could be a liability issue should you ever decide to sell the car, or someone else in your car is injured or killed due to it... it's a safety feature.... you don't go removing the seatbelt because the airbags help do ya?
to each their own... I'm not sacrificing a little safety for an extra couple dB...
Its not like the lil aluminum panel is a seat belt or airbag, That plate is not a safety feature. Its an access panel...nothing more.
- No track will sweat you for that panel.....ever. You can see the fuel cell in one of my track cars, by looking thru the front windshield
I think it just makes some people nervous when they think of a fuel tank next to their back seat....understandable, but these issues were addressed by Lexus long ago. It's probably the safest tank on the road....
- No track will sweat you for that panel.....ever. You can see the fuel cell in one of my track cars, by looking thru the front windshield
I think it just makes some people nervous when they think of a fuel tank next to their back seat....understandable, but these issues were addressed by Lexus long ago. It's probably the safest tank on the road....
Its not like the lil aluminum panel is a seat belt or airbag, That plate is not a safety feature. Its an access panel...nothing more.
- No track will sweat you for that panel.....ever. You can see the fuel cell in one of my track cars, by looking thru the front windshield
I think it just makes some people nervous when they think of a fuel tank next to their back seat....understandable, but these issues were addressed by Lexus long ago. It's probably the safest tank on the road....
- No track will sweat you for that panel.....ever. You can see the fuel cell in one of my track cars, by looking thru the front windshield
I think it just makes some people nervous when they think of a fuel tank next to their back seat....understandable, but these issues were addressed by Lexus long ago. It's probably the safest tank on the road....
and if you were truly competing at a track that followed the rules, you would be disqualified, as well as not allowed to race...
COMPLETE IHRA Fuel System rules {reprint}
Location: All fuel tanks, lines, pumps, valves, etc. must be
outside of the driver's compartment and within the confines of the frame
and/or steel body. Cool cans, fuel-distribution blocks, etc. must be located
at least 6 inches forward of the flywheel/bellhousing area on rear-wheel-
drive (RWD) cars, and on opposite side of flywheel/bellhousing area on
front-wheel-drive (FWD) cars. Fuel-pressure-gauge isolators, with steel-
braided line, may be mounted on firewall.
Tanks: When permitted by class regulations, fuel tanks located outside
body and/or frame must be enclosed in a steel tube frame constructed
of minimum 1 1/4-inch O.D. x .065 chrome moly or .118 mild-steel tubing.
All fuel tanks must be isolated from the driver's compartment by a firewall,
completely sealed to prevent any fuel from entering the driver's
compartment. All fuel tanks must have a pressure cap and be vented
outside of car body. A positive-locking screw on fuel-tank cap is
mandatory on all cars. Insulated fuel tanks prohibited. When used, fuel
cells must have a metal box protecting the part of the fuel cell that is
outside of body lines or trunk floor, excluding hose-connection area in
rear. Non-metallic fuel cells or tanks must be grounded to frame.
You may remove weight from the interior so long as it does not compromise the safety of the vehicle or expose the drivers compartment to fumes from the engine or trunk if a battery or fuel cell is located there. If the stock drivers seat and belts and mounts are not modified in any way you are OK as well.
So, is it ok to remove the panel, sure... is it a safety feature, definitely... you be the one to decide how safe you and your occupants are...
Last edited by mitsuguy; Sep 4, 2006 at 10:34 PM.
while I'm on this same theory, just the other day, I was retuning the amp and EQ in my car... my chick comes outside and says, "thats a lot louder than it was" as something inside the house was shaking almost violently... inside the car, it was no louder, but the music I was playing obviously had a note in it that carried from the driveway into the house on the second floor, and was at the exact resonant frequency of the thing that was shaking (a table lamp)... it wasn't the air that was making it shake, it was the soundwaves traveling...
You need nothing but air exchange to produce bass in a vehicle, I don't care if you shake your grandma's teeth in their glass two houses down. We'll get into wave propagation another day when the situation calls for it.
I'm leaving this thread because it is as stupid now as it was 4 yrs ago.... to remove the safety plate of a fuel cell in hopes of gaining more resonance, which is what you don't want in a car to begin with. No need to come back in and argue further on this so I am gone.
PS - No matter how many times you see the mythbusters special on nikola tesla, you cannot tune resonant frequency from an eq on a musical cd. That is a product determined by the source. You simply detuned the eq and cut boost in some areas enough to where your system became more efficient and you were able to achieve a higher spl. This is very laughable to even hear such a thing.
Last edited by O. L. T.; Sep 5, 2006 at 01:54 AM.
Please study a bit more on wave propagation. I didn't go through Engineering to have a tire guy explain to me how he rolls down tha block knockin' pictures off the wall. Your theories are completely off base.
You need nothing but air exchange to produce bass in a vehicle, I don't care if you shake your grandma's teeth in their glass two houses down. We'll get into wave propagation another day when the situation calls for it.
I'm leaving this thread because it is as stupid now as it was 4 yrs ago. No need to come back in and argue.
You need nothing but air exchange to produce bass in a vehicle, I don't care if you shake your grandma's teeth in their glass two houses down. We'll get into wave propagation another day when the situation calls for it.
I'm leaving this thread because it is as stupid now as it was 4 yrs ago. No need to come back in and argue.
Now, I hate to correct you, but you are 100% and entirely WRONG, and most likely the only reason you choose not to come back to this thread.... Sure, if there is air flow from the trunk to the cabin, like a hatchback car, then sure, there is going to be lots of energy transfer from the hatch to the forward areas of the car... I just wish I had a good, simple point in my mind... Oh wait, I do... lets tear your theory apart real quickly here... You claim sound won't travel through leather because it doesn't breathe... well, my friend, leather is a much more porous material than, oh, say, steel. Now, although music does travel through a single, contiguous compound easier than it travels through changes in compounds, it does not mean, by any means, that just because air can't travel through it, that sound waves won't travel through it...
Now, the more layers of materials, metals, etc, that are between the source of the sound and your ear will definitely decrease the intensity of said sound. Why, you ask, well, simple, although each section may be completely sealed from one another, the sound wave travels through each medium it interacts with, but when it changes mediums, from air to steel, to leather to whatever, it loses some energy, believe it or not, in the form of heat, by traveling through these different materials, it's not as efficient as it would be traveling through one contiguous material, in this case air...
If bass only has to do with moving air around, then explain to me how underwater speakers work, because they simply don't work by moving air, or water around, for that fact... and, on top of that, the speed of sound in water is MUCH higher than it is in plain air...
nice edit there last minute, but, and I entirely agree it's unsafe to remove the plate, but people are removing that plate to remove a resonating piece, not add resonance... by not having the plate there, there is one less change (and not having that piece could potentially be a big change) with materials interfering with sound waves from back to front...
(did I mention I used to sell and install car stereos as well, and have 5 dB Drag Racing trophies, that I won with 8" subwoofers, and 200 watts of power, even before there were class D amps)
Last edited by mitsuguy; Sep 5, 2006 at 01:25 AM.