Let's first consider the passband ripple spec, dB. Converting that to linear ripple amplitude gives, in Matlab,
format long; dp=10^(0.1/20)-1 dp = 0.01157945425990Let's check it:
>> 20*log10(1+dp) ans = 0.10000000000000 >> 20*log10(1-dp) ans = -0.10116471483635
Ok, close enough. Now let's set the stopband ripple to 1/10 times the passband ripple and see where we are:
>> ds=dp/10; >> 20*log10(ds) ans = -58.72623816882052
So, that's about 60 dB stop-band rejection, which is not too bad.
Setting the stopband ripple to 1/100 times the passband ripple adds another 20 dB of rejection:
>> ds=dp/100; >> 20*log10(ds) ans = -78.72623816882052which is close to the ``high fidelity'' zone of 80dB SBA