Waves has his own format for impulse responses - wir, but you can import wav files and get the responses from them. The free format for responses is wav, of course
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There are many resourses in internet when you can get impulse responses.
But Craig said something else - that in Samplitude all these goodies are INSIDE the software, for no additional cost!! Room simulator, FFT noise reduction, multiband compressor - all is there. Waves now have IR, but this year, and for a lot of money. Samplitude have convolution processor 5 years ago, and inside the software. They were the first who built a multiband compressor-expander in a native software.
I,m not selling Samplitude
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, but it's great.