After fitting some new suspension to the car and refitting refitting the parts i’d removed I had a good look at the sound tube thingy. I’ve always thought there was a weird noise which I didn’t like and presume this is partly responsible, So…I’ve removed the part that joins the resonator to the bulkhead,. It was a little tricky as there are two hard plastic tabs holding it together.
I’ve ordered the blanking plug for the hole in the bulkhead.
As you’ll see from the pictures the tube from the inlet manifold doesn’t vent into the cabin as many thnk, the resonator part is a sealed diaphragm that vibrates and therefor passes sound through the bulkhead. A bit like a speaker but instead of being driven by an electrical voice coil it’s movement is made by the intake pressure. If this wasn’t a sealed tube you’d have unmetered air getting into the engine.
Mine now simply makes its noise into the engine bay. I can’t see this being a problem.
I looked at the one in my ND, but other than being a bit of weight that seems unjustified, I have not noticed specifically the noise it causes, so will leave it.
I have ordered some sound deadening matting for the boot floor - so will try that over Easter whilst off and see if it makes a difference.
Normally I have the hood down, so it probably does not make a difference, but as I took my son to work this morning early, he did not want to “mess his hair up”, so I had the hood up on the way there and down on the way back. I noticed that it was quite loud, so thought I would try some sound deadening. There was a thread on here elsewhere, so I have ordered some of that. Will report back (with pictures!!) when I find out what the result is…
Oh I’ve already done quire a bit in terms of sound deadening,… The purists will no doubt hate my added weight in the boot and the doors but it’s much better with than without.
Where did you get the blanking plug from, please? Is there a Mazda part number?
Looks like you have a gap now - did you plug the end of the resonator tube too?
hey all.
so iv just come across some videos for “sound tube delete”
it looks like something i might do.
however before i make my decision.
i have 2 questions.
why do mazda fit a sound tube in the first place?
and
what purpose does it serve?
(because there must be more to it than just sound, mazda wouldnt waste money and resources fiting a pointless item that everyone removes anyway through all 4 marks, would they?)
The purpose is to bring more “exciting” engine noises in the cabin, because the standard exhaust nose is pathetic (due to some Californian noise regulations I would have thought.)
I just unfastened the part that bolts to the bulkhead cut some stiff foam sheet to suit the shape (like a gasket) and bolted the tube back on. Quieter in the cabin (roof up) and can definitely hear the noise better coming out of the rear.
I have just bought a 2.0 SportTech and this has this sound enhancement tube fitted. On the drive back home there was a constant drone between 2500-3000 revs, just at a leisurely motorway 60mph, it was very tiring to say the least.
Well I ended up finding 2 things about the installation, namely that drone can be removed and also that the first section of hose, and thus resonator, as it came from the factory is loose in the mounting bracket thus inducing vibration.
First of all that drone, well I just dismantled the whole lot & blocked off the intake only on the bulkhead by using a rubber cap over the orifice, then refitted the adaptor that goes over it. The drone that was initially there was now gone once the re-install was done, it was the sound enhancement kit it seems, now a lot less boomy, the result of blocking the intake at the bulkhead I would say has cured it.
The reason I removed it all was to check on the installation as it was moving, as stated, and thus vibrating over the entire length. What I found was that the clamp before the resonator fits in a recess in the hose end that goes over the resonator inlet, the clamp is too big in diameter. I built the recess back up with a piece of door draught excluder strip & once I re-installed the clamp it was a lot firmer in the location, end result was that an under engine buzzing was gone.
I wanted to leave things at stock hence putting it all back in, for me it doesn’t impede anything at the moment.
I have just checked and our 2024 RF has the sound tube fitted but I can’t say I have noticed any particular intake noise though, even with the roof up (probably wouldn’t notice it with the roof down due to the wind noise in the RF above 60mph! One question however, would removal of the tube affect the Mazda warranty?
Probably not, but the delete kit costs time and money.
So for my 25AE I simply plugged the outlet where it exits into the plenum chamber under the scuttle cover, quick and easy while that cover was off for sealing the scuttle grommets.
I removed the Sound Enhancement gubbins from my NC and IMHO it’s a lot better without it. It doesn’t have to cost much: I bought a cap-end of the right size off ebay for a couple of quid and made a blanking plate for the hole in the scuttle from a bit of spare ally that was in the garage. Never regretted removing it.
