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Discussion Starter #1
Specifically the resonator after the cats, if the OEM one was replaced by a smaller/faster flowing one how would the exhaust note be changed?
 

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Not a big difference, and not a good one either. I think the factory exhaust system on these cars is already a ltitle under-resonated as it is. third gen's are one of those cars with a well designed exhaust system to begin with and best left untouched.
 

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Discussion Starter #4
Smaller, as in length or diameter? Shorter wont do as much as no resonator with the factory muffler still in the mix, but then you still wouldnt hear much change inside and only at high revs outside and it still might be drowned out by the motor itself.

Smaller in diameter.
 

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Discussion Starter #6
Uh, why would you do that, itll choke flow.

I wanted to change the exhaust note of the car and figured the first thing to change was the resonator.
 

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In both open- and closed- pipe acoustics; diameter has no significant change on frequency, it only effects the amount of air flowing through it
Um, not sure how you come to that conclusion, bigger pipes result in a deeper tone and can completely change the tone.

OP, changing the muffler will have more effect overall.
 

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Um, not sure how you come to that conclusion, bigger pipes result in a deeper tone and can completely change the tone.
OP, changing the muffler will have more effect overall.
Resonators work using the same physics as musical instruments such as clarinet, flute, and pipe organs; but with a twist: Instead of aiming to intensify a particular band of sound, the intent is to use destructive interference to reduce the amplitude of the non-desired frequencies.

 

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Resonators work using the same physics as musical instruments such as clarinet, flute, and pipe organs; but with a twist: Instead of aiming to intensify a particular band of sound, the intent is to use destructive interference to reduce the amplitude of the non-desired frequencies.

You said diameter has nothing to do with tone, its completely incorrect. Smaller pipe will increase the pitch, larger pipes will decrease pitch. Since you brought up wind instruments, why do you think a flute and tuba have different tonal pitches and diameters?

In the original instance, using a smaller (overall) diameter resonator can change the tone, but they arent usually made that way (they are a certain ratio compared to the input/output pipe). Smaller means, smaller in/out pipe, not overall size. I suppose you could make a custom resonator, but i still stand by the statement, as someone who has designed and made exhaust systems, changing the MUFFLER will change the tone MORE than a resonator. You need to start with the largest tone modifier before you change the smaller ones. The only thing you could eliminate in the chain that would change the tone other than the muffler, would be the cat as its the most restrictive piece.
 

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You said diameter has nothing to do with tone, its completely incorrect. Smaller pipe will increase the pitch, larger pipes will decrease pitch. Since you brought up wind instruments, why do you think a flute and tuba have different tonal pitches and diameters?

In the original instance, using a smaller (overall) diameter resonator can change the tone, but they arent usually made that way (they are a certain ratio compared to the input/output pipe). Smaller means, smaller in/out pipe, not overall size. I suppose you could make a custom resonator, but i still stand by the statement, as someone who has designed and made exhaust systems, changing the MUFFLER will change the tone MORE than a resonator. You need to start with the largest tone modifier before you change the smaller ones. The only thing you could eliminate in the chain that would change the tone other than the muffler, would be the cat as its the most restrictive piece.
Both the frequency and length ratios are nearly identical and are approximately 7:1). The diameter difference is necessary because of the quantity of air needed to achieve the same SPL (volume). Application of the inverse square law is needed here, and you need to move almost 50 times the amount of air for your tuba to be at the same volume as the flute.
I actually stated "diameter has no significant change on frequency " and I'll stand by that if all things are equal- because I know when we go to a smaller pipe for the same amount of air we are going to increase the backpressure which will change the density and indirectly will change the resonant frequency.

I'm on the same page as you- leave the resonator alone and do the muffler
 

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Discussion Starter #12
You said diameter has nothing to do with tone, its completely incorrect. Smaller pipe will increase the pitch, larger pipes will decrease pitch. Since you brought up wind instruments, why do you think a flute and tuba have different tonal pitches and diameters?

In the original instance, using a smaller (overall) diameter resonator can change the tone, but they arent usually made that way (they are a certain ratio compared to the input/output pipe). Smaller means, smaller in/out pipe, not overall size. I suppose you could make a custom resonator, but i still stand by the statement, as someone who has designed and made exhaust systems, changing the MUFFLER will change the tone MORE than a resonator. You need to start with the largest tone modifier before you change the smaller ones. The only thing you could eliminate in the chain that would change the tone other than the muffler, would be the cat as its the most restrictive piece.

My muffler has already been changed and I don't really want to mess with the cats (which the catback from CorkSport does). With that in mind, that is why I have decided to swap out the resonator to see how it would change the exhaust sound especially since it's so cheap.
 

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Now see, you should have started with that info, then we could have directed you in the right direction. Now, the best thing to do is try to record your car, from the outside and inside and then describe the sounds like DONT like and where they occur (during accel, during decel, cruising etc) and how you would like it to sound. What muffler did you change it to?
 

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Discussion Starter #14
Now see, you should have started with that info, then we could have directed you in the right direction. Now, the best thing to do is try to record your car, from the outside and inside and then describe the sounds like DONT like and where they occur (during accel, during decel, cruising etc) and how you would like it to sound. What muffler did you change it to?

My OEM muffler was replaced with the CorkSport Axleback Exhaust. Overall I am satisfied with how it sounds, I just wanted a little bit more sound and maybe a bit deeper. I figured switching out the OEM resonator to a smaller bottle style one would achieve that.
 

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My muffler has already been changed and I don't really want to mess with the cats (which the catback from CorkSport does). With that in mind, that is why I have decided to swap out the resonator to see how it would change the exhaust sound especially since it's so cheap.
Waste of gas and time to get something like this done
 

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Discussion Starter #16
Waste of gas and time to get something like this done

Could say the same thing about your desire to delete the cold start, but people will do what they will to their cars/builds. Anyways, I've seen/heard it done on a 3 and it sounds interesting so I wanted to get it done as well.
 

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My OEM muffler was replaced with the CorkSport Axleback Exhaust. Overall I am satisfied with how it sounds, I just wanted a little bit more sound and maybe a bit deeper. I figured switching out the OEM resonator to a smaller bottle style one would achieve that.
I would just eliminate it all together.
 

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Discussion Starter #18
Although there was a big disagreement with this swap, I have an appointment with an exhaust shop to do this mod. Parts and labor is under $100 so if I can get a deeper tone and maybe like 10% louder it's worth it to me. Also, I will of course be making a video to document the process for my Youtube channel.
 

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Discussion Starter #20
Not so much disagreement as we didn't know you had the axle back in the first place and weren't trying to get more sound out of your stock muffler.
Oh I see, well the swap was really good and worth it! It sounds about 15-20% louder and deeper, I'm very satisfied!
 
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