Hi

I have been playing around with the free version the last two days, and Im more than impressed!!!

Infos:
Free version

This utility program was designed to allow both amateur and professional users to perform high quality sample rate conversion of WAV files. For example, if your WAV file was recorded or saved as 48000 (or 96000) file and you need it to burn onto a CD you will likely need to convert it to 44100 before that. This utility will help you to perform such conversion. r8brain also supports batch processing which is essential if you need to transfer all your project's audio data from one sample rate to another.

Two links:
voxengo
r8brain-free-src

I also know that the Pro version is around!

Infos:
Pro version

r8brain PRO is a professional sample rate converter designed to deliver an unprecedented sample rate conversion (SRC) quality. Unlike many existing SRC algorithms available on the market, r8brain PRO implements sample rate conversion processing in its full: interpolation and decimation steps without exploiting any kind of simplifications; the signal is first resampled to a least common multiple sample rate which makes conversion perfect. In the core of the SRC algorithm, we use the convolution methods of our Pristine Space convolution processor which is known for its highly precise convolution processing. This gives us high sample rate conversion quality in combination with comparably small processing times: sample rate conversion without compromises!

Like many existing SRC programs, r8brain PRO offers you a linear-phase conversion mode. But more importantly, you also have an option of using the minimum-phase conversion mode, which finally brings SRC with true analog qualities to affordable digital audio workstations: in this mode, r8brain PRO works like an ideal digital-to-analog converter followed by an analog-to-digital converter to resample the audio. This eliminates pre-ringing associated with linear-phase designs, while introducing only a minimal amount of phase coloration.

r8brain PRO can read mono, stereo and multi-channel files in both WAV and AIFF file formats, creating 16-, 24- and 32-bit mono, stereo and multi-channel WAV files in fixed and floating point formats. EBU BWF (broadcasting) extensions, extensible wave format, sample loops and textual data residing inside the file are also supported. For the sake of convenience, r8brain PRO allows you to perform batch conversions in a convenient manner.

r8brain PRO's bit-depth conversion is limited to flat dithering. We have decided not to implement noise-shaping dithering because pro audio production software available on the market usually offers the user noise-shaping dithering of some kind already. We also based our decision on the fact that the sample rate conversion process often adjusts peak structure of the original program material, thus, in many cases, making a subsequent peak-limiting a necessity. To prevent output audio from clipping we have implemented a level normalization feature.

link:
Voxengo

Cheers

 

Better SRC is in iZotope RX4, you can control steepness and cutoff frequency as you want - for fine control press "ctrl". More frequency to preserve, less aliasing, better filter implementation. As well as fine quality is dBpoweramp converter latest version; FinalCD 0.17 (Sharp) - many people like it more than RX, but is for downconversion to 44.1kHz. SoX 14.4.2 is good too - it is in latest versions of Ableton Live 9.
See here tests:
src.infinitewave.ca

So, r8brain is good, but it is good results for 2000s, I don't know whether Voxengo work on new updates, because they promised new versions with improved filters, better quality, accuracy etc. My listed above SRCs give you results much better and more accurate. You can ask me in PM, i will help you with advice.

 

Thanks mild pump milk feedback appriciated

I was only impressed by a freebie, and Im sure a proff application like iZotope RX4 can do the job much better!!

What I´ve been working on:

How much you can shrink wavs before it has an effect on the quality of the sound ..... most people will say: hi ... all shrinking will have effect on the quality, and I agree ..... but one thing is what theory tells you, another what you ear tells you!!

Cheers

 

My ears and eyes tell me: don't use strange filters that makes more digital shit. If you have better SRC, so why do you need shittier stuff?
FinalCD is free, SoX is free.
FinalCD works only with "from 48, 88.2, 96 kHz to 44.1" - works in command-line (I can teach you how to use it), there is exist GUI-version as well. SoX is command-line too, but is very complicated, there is a wide range of instruments, but FinalCD will preserve up to 22.195 Hz, then steep high-cut to 22.050 hZ. Aliasing lower than -180dB if you're converting 32 bit audio file. Linear Phase. Only pre-ringing and post-ringing will be created in the cutting area (Do you hear this small quiet ringing at 22kHz?). So there is no digital shit will be created and aliased. Or your ears want strange filter with higher aliasing and distortions? So strange thinking...
dBpoweramp has same quality as FinalCD, but it works with all sample-rates. Not Free. But I think there is free version with converter option, I dunno.
Brick 1.2 (MacOSX only) - cut begins at about 22.030. Aliasing lower than -250dB. Highest quality. Free.

 

Does Saracon compare? In particular to RX 4 - I heard it recommended recently.

Cheers