Simple DIY Sound System upgrade (pics)

guestlinger

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I recently read a forum post about suppressing resonance from the sound system (apols can’t find link) so thought I’d share my experience.

Firstly I downloaded the free iphone app called “Tone Gen”. I then Bluetooth connected to my A4 B9 B&O Sound System and systematically played all the different frequencies at fairly loud volume one by one through the system. I noted a few frequencies which seemed to cause undesirable resonance within the car. Easily the worst freq was about 230hz which really seemed to hit the natural harmonic freq of central speaker above the dash. And I also noted that if I firmly applied finger pressure to one point on the grill (see pic) then the resonance would significantly reduce. This speaker plays a lot of the mid range vocals and is a critical speaker in the B&O setup and I have historically noted certain songs did indeed generate some resonance of this central speaker. So I unclipped the speaker grill (go careful so as to not snap any lugs - I had no problems but went very slowly and carefully, prising gently with a plastic tool until the lugs starting releasing one by one) and added multiple Velcro strips - see pics. I used both sides of the tape to get a tight grip between car and speaker grill. I then replaced the grill and was thrilled that all the resonance had literally vanished. The system sound had really tightened up and was crisper and much harder hitting. So I’d advise folks to try out the Tone Gen app and if you find an undesired resonance try some simple damping to get a very cheap and fast sound system upgrade

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I recently read a forum post about suppressing resonance from the sound system (apols can’t find link) so thought I’d share my experience.

Firstly I downloaded the free iphone app called “Tone Gen”. I then Bluetooth connected to my A4 B9 B&O Sound System and systematically played all the different frequencies at fairly loud volume one by one through the system. I noted a few frequencies which seemed to cause undesirable resonance within the car. Easily the worst freq was about 230hz which really seemed to hit the natural harmonic freq of central speaker above the dash. And I also noted that if I firmly applied finger pressure to one point on the grill (see pic) then the resonance would significantly reduce. This speaker plays a lot of the mid range vocals and is a critical speaker in the B&O setup and I have historically noted certain songs did indeed generate some resonance of this central speaker. So I unclipped the speaker grill (go careful so as to not snap any lugs - I had no problems but went very slowly and carefully, prising gently with a plastic tool until the lugs starting releasing one by one) and added multiple Velcro strips - see pics. I used both sides of the tape to get a tight grip between car and speaker grill. I then replaced the grill and was thrilled that all the resonance had literally vanished. The system sound had really tightened up and was crisper and much harder hitting. So I’d advise folks to try out the Tone Gen app and if you find an undesired resonance try some simple damping to get a very cheap and fast sound system upgrade

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Good man. Might give this a go.


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I’d be interested to hear anyone else’s experience after using a resonance app. What resonated most from your sound system?

I tried it at the upper end of my music listening volume. I didn’t try max volume in case it did damage.
 
Can you explain how you started un-clipping the central speaker grill please and thank you.
 
Brilliant - My B9 S4 with B&O has been vibrating worse and worse on certain songs and it is booked in for a service next week with this problem on the list of things to investigate. To date I hadn't been able to pinpoint exactly where in the dash the was vibrating.

I tried out the Tone Gen app today and there it is at 230hz, applying pressure to the centre speaker solves it as you say.

Audi can have a print out of this thread in the car for next week's service :)
 
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next week's service :)

Hope it's not with Warrington Audi then, they refuse to do anything about this fault on mine despite me sitting a tech in the car and running the tone generator - "No fault found - Driver to monitor"

I did put some loom tape in there and it went away for a while, I've now resorted to leaving it ever so slightly unclipped on the front edge, doesn't look too much out of place and achieves the same result. Will try some thicker stuff next time I get a spare half hour.
 
Pleased to say the car went into Basingstoke Audi today who were very good about it and fitted some sound dampening material to prevent the resonance. All back to normal again!
 
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