Silence needed

Hello all

I've a 2010 Prius T Spirit - with "moonroof" and 195/65 tyres. 65k miles and a full Toyota dealer service history. I've been 'blessed' with exceptional hearing. (Or perhaps it should be 'cursed'!) I'm a piano tuner by trade.

My Prius is everything I want from a car and fairly quiet, but I wanted it even quieter. I followed all the advice that was given by: Toyota Prius 4 door Hatchback 2010- | Sound Deadener Showdown

It was brilliant information and reduced the tyre noise / road roar to sublime levels. (65dB on a highway.) I've also reduce the rear tyre pressures to 28psi - which has also helped. However...

Although the tyre noise is reduced to almost zero, I've uncovered some sort of resonate 'boom'. Probably because the tyre noise has been reduced so much, I'm now (very much) aware of a 'thump' or 'boom' every time I drive over a road bump. Any road bump produces a 'boom' from the back suspension. It's as if someone is thumping the underside of the car with a rubber hammer. It ruins an - otherwise - supremely quiet ride.

I took the car to a Toyota dealer who "tested" the suspension. (I suspect they looked the rear suspension and gave everything a good shake - and nothing more.)

I wondered if I could 'disconnect' the suspension from the car with some air suspension components, but all seemed to be concerned with lowering the suspension - not producing a quieter ride.

Am I resigned to this inherent noise from the suspension? Is there a cure?
Doe anyone have any advice?

Regards to all - Andrew

 

Thanks for your thoughts, but it seems that all the air suspension mods are for lowering the car and to change the style. I can't find any threads about making the ride quieter. Unless you can direct me to one.....