are you sure it's the speakers?
I have posted about this on my 05 hybrid. It happens when I hit a bump - most of the time - but can also happen without hitting one while cruising at a certain rev range.
Car has been in 3 times for this and I can not replicate the noise with the tech in the car. I am hoping it is nothing serious or that continuing to drive it will cause no further harm.
first, the dealer said it was a malfunction egr valve; changing it did not fix it or make it go away.
mine occurs around 16-1800 rpms. increasing rev or taking foot of accelerator makes it go away.
it is VERY frustrating to pay this much for a bloody honda and have this occur. it really ruins an otherwise FINE automobile.
please email me - I would like to keep in touch with you in case you or I find resolve with this. . . .
m_teahan@yahoo.com
I hope we can get this fix.
Please try to experiment without the audio on; when my stereo is blasting, it sounds similar when a bass riff kicks in. I have to turn it down to see if it is from the car or the music.