Higher pitched resonators

[Zenith]

It seems that most resonators available advertise that they deepen exhaust sound. Are there any resonators or exhaust devices that can increase pitch and make the exhaust really scream?

As I understand it, resonators can be built to dampen specific frequencies... Why can't they be made to dampen out the low freqs?

[MonzaRacer]

Because most people forget that low freqs are more felt over higher freqs being heard. The big reason for attenuating noise lower is higher noise really will get you in to more trouble also several municipalities have ordinances for higher freqs as they annoy dogs and at times damage glass. turbo whistle from Garrett turbos have been known to receive unwanted tickets.