Sports Exhausts & Infrasound ....

aidanodr

Hi Guys,

I recently got fitted, a wide bore stainless steel sports exhaust to my motor ( Honda Integra 98 ). I had to do this as when coming out of a carpark at nighttime onto the road - the old exhaust box snapped off the pipe due to a large pothole.

So I have had the new exhaust on the car for a few weeks - Believe it or not I have been noticing some symptoms due to the noise while driving and after - dizziness, slight nausea, discomfort. I decided to investigate and came across the term INFRASOUND:

http://en.wikipedia.org/wiki/Infrasound

"Infrasound is sound with a frequency too low to be heard by the human ear."

In another article:

http://www.washingtoncitypaper.com/display.php?id=34914

"Low-frequency noise is weird stuff. Years back I noted that infrasound—sound pitched below the hearing range of most humans, which stops at around 20 hertz—can cause dizziness."

"And in 2003, the use of 17 Hz infrasound at London concerts of experimental electronic music correlated with audience reports of “unusual experiences” including nausea, momentary anxiety, tingling, and a sense of coldness."

Do a quick search with Google on Infrasound - very interesting topic indeed.

I found another person who has had similar issues with a sports exhaust system:

http://www.pistonheads.co.uk/gassing/topic.asp?h=0&t=535579

SO - I am putting out the question - anybody else here having the same type of experiences?

Cheers
Aidan

Neilw

Who makes the exhaust you fitted?

Victor_M

aidanodr wrote: »

Hi Guys,

I recently got fitted, a wide bore stainless steel sports exhaust to my motor ( Honda Integra 98 ). I had to do this as when coming out of a carpark at nighttime onto the road - the old exhaust box snapped off the pipe due to a large pothole.

So I have had the new exhaust on the car for a few weeks - Believe it or not I have been noticing some symptoms due to the noise while driving and after - dizziness, slight nausea, discomfort. I decided to investigate and came across the term INFRASOUND:

http://en.wikipedia.org/wiki/Infrasound

"Infrasound is sound with a frequency too low to be heard by the human ear."

In another article:

http://www.washingtoncitypaper.com/display.php?id=34914

"Low-frequency noise is weird stuff. Years back I noted that infrasound—sound pitched below the hearing range of most humans, which stops at around 20 hertz—can cause dizziness."

"And in 2003, the use of 17 Hz infrasound at London concerts of experimental electronic music correlated with audience reports of “unusual experiences” including nausea, momentary anxiety, tingling, and a sense of coldness."

Do a quick search with Google on Infrasound - very interesting topic indeed.

I found another person who has had similar issues with a sports exhaust system:

http://www.pistonheads.co.uk/gassing/topic.asp?h=0&t=535579

SO - I am putting out the question - anybody else here having the same type of experiences?

Cheers
Aidan

You can be sure that everyone you've driven past with the 'sports exhaust' on has been suffering from all those symptoms you described.

I think it's called getting a taste of your own medicine. I assume taking the 'sports exhaust' off and putting on a standard one will solve the problem.

Mr.Diagnostic

Ahh…………….So this would explain the origins of drifting. The loud exhausts came first and the poor lads were so dizzy all they could manage was to go round in circles

peasant

interesting topic, no need to tease the OP

tw0nk

Mr.Diagnostic wrote: »

Ahh…………….So this would explain the origins of drifting. The loud exhausts came first and the poor lads were so dizzy all they could manage was to go round in circles

haha great post!

aidanodr

peasant wrote: »

interesting topic, no need to tease the OP

Thanks Peasant,

I popped this topic up as a serious topic, I didnt anticipate this barage of trite replies. It would seem that their are people here who are venting annoyance at the boy racer fraternity for noise created by sports exhaust systems. Thats all fine - but as I said this WAS not the reason for my placing this topic here. I would appreciate replies in the spirit of the topic asked. Maybe start another thread about sports exhaust noise annoyance if ye want to persist on this line here.

I had two choices re an exhaust for my 98 IMPORT Integra, either go the main dealer route for another last third standard exhaust - I was being quoted upwards to €1000 for the job OR get a "Sports Exhaust" fitted which cost a more manageable €199. I am selling this car also - the only people who will buy this is a "boy racer" so the sports exhaust should be seen as an "enhancement".

So can we please get back on topic here and cut the snide remarks!

NEILW - good question, I would have to call the specialist guys who fitted it. Why would this be of concern?

I also have been playing music for years and can appreciate low resonant tones down in the sub bass level, hence my interest in this.

Aidan

T-Maxx

aidanodr wrote: »

...I had to do this as when coming out of a carpark at nighttime onto the road - the old exhaust box snapped off the pipe due to a large pothole.

Wrong. You wanted to do this and in the process annoy the heck out of everybody else. You could have fitted a standard, proper, real exhaust and avoided the pothole.

Biro

T-Maxx wrote: »

Wrong. You wanted to do this and in the process annoy the heck out of everybody else. You could have fitted a standard, proper, real exhaust and avoided the pothole.

Much to complain about, haven't you? You don't like sports exhausts, so go mad at anyone who installs one. Some tree hugging hippies hate cars, so they'd slag you off about owning your car. You wouldn't take them seriously, would you?

rebel.ranter

Is there a way that we can reproduce this noise? Is there a wav file we can download? I coudl experiment with it in the office here.

I know Nissan were playing around with cabin noise elimination in the Primera. They were using some device to counteract the sound wave generated by road noise with an alternate sound wave effectively producing a null sound wave. i.e. silence.
Not sure if it ever made it to market or how effective it was. I read/saw a TV programme about it years ago.

Just another motoring-sound connection.

peasant

T-maxx & Biro ...stick to the topic please

aidanodr

T-Maxx wrote: »

Wrong. You wanted to do this and in the process annoy the heck out of everybody else. You could have fitted a standard, proper, real exhaust and avoided the pothole.

Hey TMAX,

YOUR ABSOLUTELY RIGHT - you found me out. Glad you know me all my life, actually so it was you standing on the foot path when I pulled out of the car park - now I know how you can advice about avoiding the pothole. Thank Thank Thank you, you are the best friend a guy could have. I will now be sure to spend the €1000 and put on a "standard, proper, real exhaust", anything for you buddy - Oh I feel so cleansed now, at last I am among the righteous again!

Rebel.Rant - I could try rustle up a recording WAV of the sound. The points you make are interesting. From my readings about Infrasound their seems a dirth of info around this and general car engine/exhaust sound, particularly in cities and towns.

The two areas which have got larger concentration is Music / Subbass & the Paranormal.

Re the latter - THIS GETS WEIRD & STRAYS OFF THE CAR TOPIC -As in the effects of Infrasound on us humans when exposed to it and certain feelings of dread we get as a symptom. Some saying that "Paranormal Hotspots" are actually areas of high Infrasound:

http://noghosts.com/2008/04/20/the-effects-of-infrasound/

This popped up as an aside when I was googling around on the actual topic at hand,

Cheers
Aidan

T-Maxx

T-Maxx wrote: »

Wrong. You wanted to do this and in the process annoy the heck out of everybody else. You could have fitted a standard, proper, real exhaust and avoided the pothole.

Sports exhausts are not always loud. The good ones perform quietly as stock at low revs and only get louder when you put the welly down.

Matt Simis

rebel.ranter wrote: »

Is there a way that we can reproduce this noise? Is there a wav file we can download? I coudl experiment with it in the office here.

I think you will have difficulty getting speakers or standard headphones to playback such low frequencys, most headphones start at 20hz and speakers 80hz. Subs could reproduce lower frequencies (but dont know if that low). Some premium earphones claim to reproduce 10hz and up, but cant see how you "know" its working.

aidanodr

rebel.ranter wrote: »

Is there a way that we can reproduce this noise? Is there a wav file we can download? I coudl experiment with it in the office here.

Hi Rebel,

Your wish is my command

I stuck the recorder right up under the back end of the exhaust. I had to convert the audio from WAV to MP3 - the WAV file was large enough, but I could shorten the WAV file length if necessary.

http://www.tidalsound.com/misc/

This is 459kb in size. Right click the file name link and "save target as". Out with the SPECTRUM ANALYSER ... Knock your self out

The sound you hear as I said is real close up - The car is idling.

Cheers
Aidan

alexmcred

Is it possible that you have some exhaust fumes coming back into the cabin?

aidanodr

Hi alexmcred,

Checked all that - no monoxide in the cabin. Between CO2 detectors AND the mechanic fitting a surgical glove over the end of the pipe - it ballooned straight away, indicating no leaks.

Interestingly - if I use those sponge ear plugs on long journeys all is fine. They say some are more suseptible than others to sub sounds. Other people have driven this car with no difficulty.

Now I realise - yes - I could change the exhaust. This is not the point of this topic, the object was to bring up this interesting thing called infrasound and noise from sports exhausts / car engines in general and the effects of same on people.

Cheers
Aidan

Victor_M

So you wear ear plugs in your car when you are driving around to make the journey more comfortable for you Glad I don't live anywhere near you.

And your appreciation for Subbass low frequency sounds, is that code for an annoyingly loud sound system to accompany the exhaust?

Have you had your hearing checked by a doctor? In case it's been or is being damaged?

All jokes aside, why not put on a non oem quieter exhaust, surely there are quieter cheaper options to the €1000 one.

Victor_M

Victor_M wrote: »

So you wear ear plugs in your car when you are driving around to make the journey more comfortable for you Glad I don't live anywhere near you.

And your appreciation for Subbass low frequency sounds, is that code for an annoyingly loud sound system to accompany the exhaust?

Have you had your hearing checked by a doctor? In case it's been or is being damaged?

All jokes aside, why not put on a non oem quieter exhaust, surely there are quieter cheaper options to the €1000 one.

lol you didn't even read the thread did you?

Victor_M

ronoc wrote: »

lol you didn't even read the thread did you?

If you bothered your hoop to read the thread fully you would have seen that I was the second person to reply, yes I have read the thread, just don't understand the need to get into the physics of low frequency sound when all he has to do is put on a cheaper quiet exhaust and turn down his stereo.;)

mountain

OP,

maybe this is a stupid suggestion, but,
can the person who fitted the exhaust some how "tune it", by putting a slimmer pipe inside the last part of it.

If this was done, then you could determine if it is the sound, that is causing the problem.

Oh, and i fitted a sports exhaust to my 45 year old volvo last year,
so its a bit of a generalisaton to say that they are only for boy racers.

SEPT 23 1989

put the original one back on, Honda dont spend billions of yen developing the exhaust system on the integra for nothing what will you gain anyway?? 7-10bhp

craichoe

SEPT 23 1989 wrote: »

put the original one back on, Honda dont spend billions of yen developing the exhaust system on the integra for nothing what will you gain anyway?? 7-10bhp

Ahh cmmere. .. theres often times when i used aftermarket parts on my bike, simply because they did the same job .. ever hear of K&N ? ... everyone uses their stuff .. ffs if you go to an indy garage most of the time they use K&N stuff. Where did you read they spent billions of yen on developing the exhaust ? Its more than likely a stock exhaust thats shared across a range.

And how much is that in real money .. i.e euros.

richie_rvf

Very interesting!

Do you think it could be to do with the length of the exhaust? Maybe it it was lengthened (or shortened) it would change the frequencies?

You should count yourself lucky that you didn't accidentally discover 'brown noise'

JHMEG

craichoe wrote: »

Its more than likely a stock exhaust thats shared across a range.

If it's an ITR it was developed specially for it, and is recognised to be the best for the car in terms of power. No aftermarket exhaust has bettered it afaik, and many big name ones actually reduce power.

SEPT 23 1989 wrote:

what will you gain anyway?? 7-10bhp

Try -10 to +3 maybe.

aidanodr

Victor_M wrote: »

So you wear ear plugs in your car when you are driving around to make the journey more comfortable for you Glad I don't live anywhere near you.

Nope,


What I said was "if I use those sponge ear plugs on long journeys all is fine" - IF and LONG JOURNEYS. I dont remember saying anything about "you wear ear plugs in your car when you are driving around". Loads of people seem to be making huge generalisations AND mis quoting when it suits their point. Please just be accurate when you are quoting!

Victor_M wrote: »

when all he has to do is put on a cheaper quiet exhaust and turn down his stereo.

All this is fine - but what do you consider cheap? As I said this is a jap import, parts can be different from Irish cars. AND before ye go ranting about how bad / stupid people are who buy Jap imports - the likes of the INTEGRA is not available as an Irish/European model.

Generally - thanks to all those who are eluding to the fact that I am a Boy Racer - far from it indeed age wise, but I will take the compliments all the same

Cheers
Aidan

Wertz

aidanodr wrote: »

Hi Rebel,

Your wish is my command

I stuck the recorder right up under the back end of the exhaust. I had to convert the audio from WAV to MP3 - the WAV file was large enough, but I could shorten the WAV file length if necessary.

http://www.tidalsound.com/misc/

This is 459kb in size. Right click the file name link and "save target as". Out with the SPECTRUM ANALYSER ... Knock your self out

The sound you hear as I said is real close up - The car is idling.

Cheers
Aidan

I can't help with your exhaust problem, but I know enough to tell you that your recording device/microphone most likely didn't pick up the infrasound and that even if it did, the conversion to mp3 would cut any such inaudible frequences....so the trouble of reproducing the sound, assuming you had the necessary sub, won't arise.
It's something that needs to be witnessed in the flesh.
I can't see how earplugs would stop this....infrasound is "felt" by the whole body...the ear drum can't even react/vibrate at that low a frequency.
Someone suggested shortening or lengthening the exhaust....this may work as infrasound from something like an exhaust would be down to resonance at a certain frequency culminating from engine revs. Hence change the length of the pipe and you change the frequency at which the resonance occurs...

Sorry to sound obvious, but have you completely ruled out motion sickness or any other illness?

Victor_M

aidanodr wrote: »

Nope,


What I said was "if I use those sponge ear plugs on long journeys all is fine" - IF and LONG JOURNEYS. I dont remember saying anything about "you wear ear plugs in your car when you are driving around". Loads of people seem to be making huge generalisations AND mis quoting when it suits their point. Please just be accurate when you are quoting!




All this is fine - but what do you consider cheap? As I said this is a jap import, parts can be different from Irish cars. AND before ye go ranting about how bad / stupid people are who buy Jap imports - the likes of the INTEGRA is not available as an Irish/European model.

Generally - thanks to all those who are eluding to the fact that I am a Boy Racer - far from it indeed age wise, but I will take the compliments all the same

Cheers
Aidan

Fair enough, apologies, I was generalising a bit, sorry about that:)

As someone else suggested, could you get the current exhaust tuned or muffeled a bit to change the frequency, as it seems to be fairly specific levels that cause this Infrasound?