Hi Stehno,
If we know that vibration alters the signal flowing through a component we must endeavor to eliminate as much of the vibration as possible with full elimination being our ultimate goal. It is true that there are not ANY vibration control products from ANY company that are presently able to eliminate all destructive vibration - although we have prototype units in our lab that come relatively very close. In the future we (the collective “we” in the audio community) will be able to attain that goal through further research and development. But even though we do not yet have that ultimate capability we should resist the urge to go down compromised paths such as the misguided notion of “tuning” vibration. We must also reassess our present methodologies and determine if they are adequate to the task or if they only achieve partial success - such as the attempt to “drain” vibration.
In the here and now, eliminating as much vibration as possible – and minimizing the amount of vibration being allowed to affect the components in the first place – should be the goal.
As far as the car stereo question is concerned: What you are experiencing in your car which is a number of cars ahead of the “boom box” vehicle is: 1) vibration that is being directly coupled through the ground, 2) air-borne vibration that is sent directly from the offending vehicle and 3) resonances in your car that are being activated.
The woofers in the “boom box” car stereo have been shoehorned onto a cabinet and vehicle interior that are far too small for the Thiele/Small parameters of the driver. This results in a system “Q” than is far higher than appropriate and a severely disproportionate amount of low frequency energy (but let’s also not forget about the bank of EQs that have all of the low frequency sliders pushed up to maximum!). The low frequencies have a lot of energy behind them and easily travel the distance through the air from that vehicle to your vehicle (the air in between the vehicles cannot absorb all of that energy plus the ground is being excited by the air-borne low frequency energy which is added to the directly-coupled waves traveling towards your vehicle). They also excite the windows, metal panels and plastic parts of your vehicle and cause them to resonate. Because you are in physical contact with your car, you will experience a visceral response which can be physically uncomfortable. Even though both vehicles are on air filled tires, the tires have been designed and optimized to support a heavy vehicle traveling down a road and not necessarily to make audiophiles in the car happy. The tire walls are thick and rigid plus the air pressure in the tire is too high to provide effective isolation from the audio frequencies. If you didn’t have to actually drive the car you could deflate the tires as much as possible without having them “bottom out” and achieve a much more effective level of vibration isolation.
Best Regards,
Barry Kohan
Disclaimer: I am a manufacturer of vibration control products.
If we know that vibration alters the signal flowing through a component we must endeavor to eliminate as much of the vibration as possible with full elimination being our ultimate goal. It is true that there are not ANY vibration control products from ANY company that are presently able to eliminate all destructive vibration - although we have prototype units in our lab that come relatively very close. In the future we (the collective “we” in the audio community) will be able to attain that goal through further research and development. But even though we do not yet have that ultimate capability we should resist the urge to go down compromised paths such as the misguided notion of “tuning” vibration. We must also reassess our present methodologies and determine if they are adequate to the task or if they only achieve partial success - such as the attempt to “drain” vibration.
In the here and now, eliminating as much vibration as possible – and minimizing the amount of vibration being allowed to affect the components in the first place – should be the goal.
As far as the car stereo question is concerned: What you are experiencing in your car which is a number of cars ahead of the “boom box” vehicle is: 1) vibration that is being directly coupled through the ground, 2) air-borne vibration that is sent directly from the offending vehicle and 3) resonances in your car that are being activated.
The woofers in the “boom box” car stereo have been shoehorned onto a cabinet and vehicle interior that are far too small for the Thiele/Small parameters of the driver. This results in a system “Q” than is far higher than appropriate and a severely disproportionate amount of low frequency energy (but let’s also not forget about the bank of EQs that have all of the low frequency sliders pushed up to maximum!). The low frequencies have a lot of energy behind them and easily travel the distance through the air from that vehicle to your vehicle (the air in between the vehicles cannot absorb all of that energy plus the ground is being excited by the air-borne low frequency energy which is added to the directly-coupled waves traveling towards your vehicle). They also excite the windows, metal panels and plastic parts of your vehicle and cause them to resonate. Because you are in physical contact with your car, you will experience a visceral response which can be physically uncomfortable. Even though both vehicles are on air filled tires, the tires have been designed and optimized to support a heavy vehicle traveling down a road and not necessarily to make audiophiles in the car happy. The tire walls are thick and rigid plus the air pressure in the tire is too high to provide effective isolation from the audio frequencies. If you didn’t have to actually drive the car you could deflate the tires as much as possible without having them “bottom out” and achieve a much more effective level of vibration isolation.
Best Regards,
Barry Kohan
Disclaimer: I am a manufacturer of vibration control products.