does this help?
I don't understand what everyones going on about.I've heard T Lines slow soundwaves through their stuffing and I think 60 Hz is close to a Kickdrum at 65Hz, so the www says on music type sites, maybe at a high spl this frequency can be quite physical. Listen to Hardcore from say DJ Sharkey on Bonkers XI CD, its pretty kickdrum lead and although the beats per minute are turned up, you will get it in the chest anytime and most likely straight from the driver, not a reflection from the windscreen. Afterall, if the driver is in close proximity, ie behind the drivers seat, I'm pretty sure you'd feel the driver.
By the way, whats the Fs of your chest?
http://www.caraudiohelp.com/newsletter/cabin_gain.htm
Cheers mikee55
ps hello richie000boy, hope you're well, sir?
I don't understand what everyones going on about.I've heard T Lines slow soundwaves through their stuffing and I think 60 Hz is close to a Kickdrum at 65Hz, so the www says on music type sites, maybe at a high spl this frequency can be quite physical. Listen to Hardcore from say DJ Sharkey on Bonkers XI CD, its pretty kickdrum lead and although the beats per minute are turned up, you will get it in the chest anytime and most likely straight from the driver, not a reflection from the windscreen. Afterall, if the driver is in close proximity, ie behind the drivers seat, I'm pretty sure you'd feel the driver.
By the way, whats the Fs of your chest?
http://www.caraudiohelp.com/newsletter/cabin_gain.htm
Cheers mikee55
ps hello richie000boy, hope you're well, sir?
T lines don't slow the wave down, just gracefully attenauate them. Anything that slows waves down will introduce distortion. Also I'd imagine it would invole some rather strange physics.
Hi Mike, I'm ok just my PC is not liking the new hard disc at the moment, and I'm a bit stuck with it. So I have been offline at home for almost a week now with no access to my email.
Hi Mike, I'm ok just my PC is not liking the new hard disc at the moment, and I'm a bit stuck with it. So I have been offline at home for almost a week now with no access to my email.
care to explain why im wrong?
with details please...
the front part of a bandpass box doesnt just act as a low pass filter....it does more than that.
it combines and concentrates the pressure in an enclosed space and releases it through one point.
contrary to popular belief, bass can be aimed.
if you have a home stereo with subs, take a piece of wooden sheet and angle it to the direction your aiming at, then walk to that spot and see for yourself....you must cover the top also...or else it will go in two directions.
im not just making this stuff up, if you actually tried it you would see for yourself.
with details please...
the front part of a bandpass box doesnt just act as a low pass filter....it does more than that.
it combines and concentrates the pressure in an enclosed space and releases it through one point.
contrary to popular belief, bass can be aimed.
if you have a home stereo with subs, take a piece of wooden sheet and angle it to the direction your aiming at, then walk to that spot and see for yourself....you must cover the top also...or else it will go in two directions.
im not just making this stuff up, if you actually tried it you would see for yourself.
I sit corrected
Yes T-lines attenuate, it was a decade ago that I was reading on them. As for steering bass, me thinks its over my head and I'm overloading my grey cells at the mo with the earth on my car.
Rich, I cleaned my CPU heatsink and fan last night and forgot to plug the fan back in after I stripped the dust.I'm so glad my bios set its siren off. I had fully booted and played an mp3 before the alarm. Oops
Yes T-lines attenuate, it was a decade ago that I was reading on them. As for steering bass, me thinks its over my head and I'm overloading my grey cells at the mo with the earth on my car.
Rich, I cleaned my CPU heatsink and fan last night and forgot to plug the fan back in after I stripped the dust.I'm so glad my bios set its siren off. I had fully booted and played an mp3 before the alarm. Oops
i agree you can direct bass waves, so it would be louder in a general area.
the only way it is possible to slow down a soound wave would be ex.
on a digital audio software like cubase or nuendo, you can stretch the audio wave. so if you had a 65hz wave and took part of it and stretched it out to say 30hz. that in a sense would be slowing it down.
But Moch1 is the speed of sound. the only time that changes in the amount would be do to the atmosphere. of course you could put barriers up and the wave might take longer to get to a point but it is bouncing from point to point at the speed of sound.
the only way it is possible to slow down a soound wave would be ex.
on a digital audio software like cubase or nuendo, you can stretch the audio wave. so if you had a 65hz wave and took part of it and stretched it out to say 30hz. that in a sense would be slowing it down.
But Moch1 is the speed of sound. the only time that changes in the amount would be do to the atmosphere. of course you could put barriers up and the wave might take longer to get to a point but it is bouncing from point to point at the speed of sound.
My original theory and drawings are too messy so I had to erase a lot of stuff and some comments. I used Ti89 to substitute values into different equations and then link those equations to find out values for variables of interest. Most of it was calculated by playing with numbers and brute substitutions into linked equations that gave delta time of waves. The goal was to get delta time between wave 1 and wave 2 & 3 to as close as possible to 0.003412s to cancel properly in this car. Very long calculation was done over 3 day period to come up with something reasonable.
Its simple
Hi, get an oscillator and frequency counter.Do a sweep till you find the frequency that vibrates your chest the most. This gives Fs of chest. Insert a 5 band graphic into your system which has Fs at the centre band. Push the centre slider up to +120db full boost, bring the remaining sliders down to get inverted smiley. This should make your sub pump your chest....
This is most unconventional, the theorey looks mad. Does it count for the shape of the glass?, and what would happen if the Transposistion thingy was the same shape as the windscreen?, amd where would I put my feet if I wanted a ride in the back? Where did you get your theorey? I'm terrible with math, but still can't understand why you minimize 60hz at the seat posistion?I found with, say, Wavelab, if you eq out 60hz and 120hz(1st and 2nd harmonic?),you can boost 30 hz fundamental by a massive amount. Used to do this to get more bottom end. Bit boomy though.
Cheers mike
Hi, get an oscillator and frequency counter.Do a sweep till you find the frequency that vibrates your chest the most. This gives Fs of chest. Insert a 5 band graphic into your system which has Fs at the centre band. Push the centre slider up to +120db full boost, bring the remaining sliders down to get inverted smiley. This should make your sub pump your chest....
This is most unconventional, the theorey looks mad. Does it count for the shape of the glass?, and what would happen if the Transposistion thingy was the same shape as the windscreen?, amd where would I put my feet if I wanted a ride in the back? Where did you get your theorey? I'm terrible with math, but still can't understand why you minimize 60hz at the seat posistion?I found with, say, Wavelab, if you eq out 60hz and 120hz(1st and 2nd harmonic?),you can boost 30 hz fundamental by a massive amount. Used to do this to get more bottom end.
Bit boomy though.Cheers mike
Re: Its simple
I came up with this design by myself. When I built this box and started playing with sub’s elevation to change distance X and finely tune cancellation effect; I realized how much I don’t know about this box. The final result, though, is that bass pounds a lot harder in the chest than at your seats vs any conventional setup that I had before.
60hz is f –frequency of penetration and the center wave cancellation distribution at the surface of polypropylene pillow. I used this number because 60hz is the most annoying frequency of seat oscillation. At 35Hz or 100Hz the seat vibrations are unnoticeable with any box.
The rear seat was sacrificed for the sake of having minimum oscillation of front seats. I was trying to figure out the role of 3d shape of glass curvature by hand without success. You might be able to do it with cylindrical coordinate system. I just want to forget about it.
Here is a peace of old draft with an attempt using Cartesian coordinate system with a lot of partial derivatives
mikee55 said:Hi, get an oscillator and frequency counter.Do a sweep till you find the frequency that vibrates your chest the most. This gives Fs of chest. Insert a 5 band graphic into your system which has Fs at the centre band. Push the centre slider up to +120db full boost, bring the remaining sliders down to get inverted smiley. This should make your sub pump your chest....
This is most unconventional, the theorey looks mad. Does it count for the shape of the glass?, and what would happen if the Transposistion thingy was the same shape as the windscreen?, amd where would I put my feet if I wanted a ride in the back? Where did you get your theorey? I'm terrible with math, but still can't understand why you minimize 60hz at the seat posistion?I found with, say, Wavelab, if you eq out 60hz and 120hz(1st and 2nd harmonic?),you can boost 30 hz fundamental by a massive amount. Used to do this to get more bottom end.
Cheers mike
I came up with this design by myself. When I built this box and started playing with sub’s elevation to change distance X and finely tune cancellation effect; I realized how much I don’t know about this box.
The final result, though, is that bass pounds a lot harder in the chest than at your seats vs any conventional setup that I had before.60hz is f –frequency of penetration and the center wave cancellation distribution at the surface of polypropylene pillow. I used this number because 60hz is the most annoying frequency of seat oscillation. At 35Hz or 100Hz the seat vibrations are unnoticeable with any box.
The rear seat was sacrificed for the sake of having minimum oscillation of front seats. I was trying to figure out the role of 3d shape of glass curvature by hand without success. You might be able to do it with cylindrical coordinate system. I just want to forget about it.
Here is a peace of old draft with an attempt using Cartesian coordinate system with a lot of partial derivatives
Richie YES! boundry reinforcement. but if you think about it, accoustic space or not, you've heard of an ampitheater right? designed to amplify sound waves. way back in the day, Romans, this is ancient technology.richie00boy said:
and its not so much space its being driven in cause the room hasnt changed size. its the walls acting as reinforcement as you quoted
Amphitheatres work in the same way as satellite dishes - they focus the sound which can provide some gain. This is not the same as what happens with the truck rear space.
My second para in your quote is the reason it gets quieter when you open the rear door. Also when you open any door or window, the driving mode of the interior space will change from pressure mode to wave move, which basically takes out most if not all of the cabin gain (or room gain in a house).
My second para in your quote is the reason it gets quieter when you open the rear door. Also when you open any door or window, the driving mode of the interior space will change from pressure mode to wave move, which basically takes out most if not all of the cabin gain (or room gain in a house).
ok, i'll stop here. cause we aint gonna agree, completely at least.
A natural amphitheatre is a performance space located in a spot where a steep mountain or a particular rock formation naturally amplifies or echoes sound, making it ideal for musical and theatrical performances
thats from wikapedia. not that wiki is correct 100% of the time but i agree with its statement, and if you cut the car in half and looked at a picture of the hollywood amphitheatre one could say they are closely alike. and i was thinking before i noticed the trunk was sealed that the sub was free air and just on a baffle that didnt cover the backseats.
anyways i'll end my debate right here. you feel free to put in your closing statement before the jury deliberates.
peace
A natural amphitheatre is a performance space located in a spot where a steep mountain or a particular rock formation naturally amplifies or echoes sound, making it ideal for musical and theatrical performances
thats from wikapedia. not that wiki is correct 100% of the time but i agree with its statement, and if you cut the car in half and looked at a picture of the hollywood amphitheatre one could say they are closely alike. and i was thinking before i noticed the trunk was sealed that the sub was free air and just on a baffle that didnt cover the backseats.
anyways i'll end my debate right here. you feel free to put in your closing statement before the jury deliberates.
peace
I like the "slam" from ported enclosures. I'm still 17 in that regard.
Video of my PC sub. I couldn't find a small sub that did what I wanted it to do, so I built my own. It ended up a bit bigger than I initially wanted.
My current car sub, though not exactly ported:
It's quite forceful in the 40-45hz range.
Video of my PC sub. I couldn't find a small sub that did what I wanted it to do, so I built my own. It ended up a bit bigger than I initially wanted.
My current car sub, though not exactly ported:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
It's quite forceful in the 40-45hz range.
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