Is it really possible to reproduce low frequency in car?

[Sarong1]

Bro Jeff, I seem to be bad hor??? But this is what I would describe as sharing of knowledge lor... What else can we write besides system, CD and installers??? There must be ways to get this ICE forum go through interim upgrading program mah...guests and newbies to the forum would then be attracted and a even larger pool of knowledge would then be poured in to this reservior...

[Sarong1]

Hi Hyun, this discussion is interesting. Let's see what others think about it ya???

 

Anyhow, the article was abstracted from a audio magazine that covers car audio as well, thought it was pretty interesting.

[Jeffteng]

u bad? perish the tot~~~ u one of the best reveiwer there is here, really , jus that i read too much specs i go headache heeheee, paiseh it's my bad~~ kekeke

[Sarong1]

Bro Jeff, me is barely one year in the ICE National Service, cannot live up to your title... You really know how to tickle the bola man...

[Darkness]

[reply]

the idea about wave propagation is that the air particle itself is not flying the entire distance. it's vibrating due to the vibrations of the neighbour particle. the vibrations have an amplitude (the extent of movement from its original position) and to generate a wavefrom, all it needs to do is go through the sine wave form of its frequency,reply]

 

Yes bro u are correct...the air particles merely transfer the energy from one particle to the other.

 

Looking at it from a point of pressure waves...

 

For instance, when an excess pressure is produced on some region of the air (by say a speaker cone moving), that region tends to expand towards the neighbouring zones. And this becomes a chain effect. The pressure disturbance will thus propagate through the air, and eventually it will reach the receiver.

 

Pressure can be related to energy. (that part we can leave it out for now i guess )

Edited February 18, 2006 by Darkness

[Jeffteng]

pls bro , we all here to learn from each other, me no title, probably only title i have is FULL OF BULLS.H.I.T., we are all learners~~~ heehee

[Twnll]

This is correct!

[Sarong1]

TWNLL, you have any views on the topic itself to share?

[Twnll]

Inside of a car is like a pressured vessel hence sound energy does not need the distance to cover the complete cycle. What we hear in terms of lower frequencies is changes in air pressure detected by our ear drums. I believe the very low frequencies we get from a car is different from that of a home audio system. A home audio system is to be perfectly honest, more accurate sounding than what we can get in a car, bar the room's resonance.

 

I always wonder about all the peaks and dips in a car given the acoustics which works against getting a good flat response...

[Sarong1]

Hello, how is the going, Twnll?

 

Yes, you understood the point which is exactly what was originally posted but of course, it requires double-reading. And we will definitely agree that home acoustic and car is two different story after all. Each presents many aspects of problem unique in its own class but the criterion and concept of a decent sound reproduction is generally about the same.

 

"...But in fact, it is possible. That is because car acoustic actually presents a near vacuum environment. The reason why sub freq range can exist in the car is because of the changes of internal car air pressure that creates what is termed as Transfer Function of Pressure Changes. Now, if the woofer and subwoofer have been installed properly and there are no serious leakages of signal or acoustic cancellation, it is really possible. Adding the fact that if the positioning of the speakers are in harmony with the subwoofer, the pressure in the car will react according to the audio, thus creating what we hear as sub freq, better still seismic (which is the ranges we feel)."

 

Yes, I must also say that car acoustics is "uniquely ICE", some folks have experienced different SQ in cars that have leather and synthetic seats, then we have another group that said conti cars seem more favourable than japanese/korean made in SQ, whatever.

 

Even Kwongwing's car, which is considered the biggest in our grouping, presents another experience of ICE simply because of its car acoustic; superb width to present wide soundstage and the length for air pressure changes. We can try placing different sub in his car to listen out for the effects, taking into consideration that all the requirements are constant and unbiased.

 

Therefore, a lesson that can be learnt from here is that ICE by itself is in fact not a simple feat of merely assembling them in the correct position and expect it to perform. There are a lot considerations that perhaps ICE craze should take, one example is how low freq reacts in different car acoustic etc.

 

I opine that as long as one is serious enough of the ICE in his car, there are in fact loads of knowledge that are worth looked and studied into.

 

Each car presents an experience that will never repeat itself in another car and each ICE experience is always unique by its own and with a unique story to tell...

Edited February 19, 2006 by Sarong1

[Hyun]

i might have missed the point, but do appreciate what was mentioned about the nature of contents within the room (seats, material etc).

 

but when discussing physics, a car and an enclosed room would be considered the same entity. the differences lie in the shape and content.

 

therefore when it comes to figuring out whether a subsonic wave longer than the length of the room can be reproduced, the theory should be identical whether it is for car or big room. i.e. the car environment is not "exceptional". it's just different, but should utilise the same theory.

[Kermit]

A few things i want to question:

 

How small must the room size be in order to compare it to a car? Toilet? Besides, room walls are normally made of concrete, unless you're talking about a recording studio lah...It is common sensical that due to this space-volume difference, the magnitude of vaccumn or air pressure created by sound waves inside the car compared to a typical room would be different. Whatever the case is, the fact that a vaccuumed space is ideal for reproduction of low freq sound waves can hardly be doubted. You try opening your car doors and boot and hear if your sub is still playing what it's supposed to...?

 

I am no expert, just using whatever common sense I have...

[Wankie]

1 small size transistor radio can fill up the whole toilet with sound liao leh.

 

you would need an industrial size ghetto blaster stereo to do the same in a car

Edited February 21, 2006 by Wankie

[Sarong1]

Hyun, I guess you have only read the first portion of my posted article and could have highly missed the point.

 

It said that it was possible to create the subsonic ranges within a car because of the phenomon called Transfer Function of Pressure Changes. I believe this is the same kinda phenomenon in HDB room, less the boomy effects.

 

I register your point that subsonic wave is indeed longer than the length of a car and sometimes a HDB living room however, I choose to think that a car acoustic and that of the room is different, not at all the same entity. Why is it different, the volume of a room and that of a car speaks for itself and this is also illustrated in Kermit's response.

 

So, the subsonic ranges heard and felt in a room is entirely different from a car, why??? Because the vacuum space we were talking about is determined by the volume of the space, the structural and material of the "wall" and the contents within are important factors that determine if subsonic range could be reproduced the way we perceive it to be.

 

Also, there are thinking that a car is perhaps the most ideal acoustic to experience subsonic ranges because of its sheer volume of space and therefore, the ease of creating the pressure, using nominal number and size of amp and power supply.

 

To summarise, I opine that a car acoustic will always be a car acoustic, we have to study it by itself. We should continue to seek more knowledge and intellectual discourse so that we can fully understand why sound reproduction in cars are such. Through which, acquire equipments and systems that best suit our car acoustic.

 

I hope I am not confusing you, Hyun....