Mono-a-Mono

This tool helps remove noise when converting mono recording in older mediums to stereo.

Mono-a-Mono is an audio restoration program for creating stereo recordings from vintage media such as 78 rpm records, cylinder recordings, and any other mono recording. It helps enhance the quality of the output stereo recording by filtering the scratch, pop, cackle, etc. noises associated with these recording. The cleaner recording then could be played through your modern stereo music players. If you have a plan to convert your old stock of records and convert them once for all to digital format and save these from further deterioration, this tool could be quite handy. It can enhance digital recordings of old records (whether 78, 45, or 33 rpm, shellac, acetate or vinyl), audio tapes (reel-to-reel or cassette), or even cylinder recordings, provided only that the playback and digitization of the signal has been performed in stereo, but the original source was mono.

The tool uses a two-step process. In the first step, it uses a simple method to remove the clicks. Other noise components are removed through implementation of a higher order adaptive filter. Most noise components are rendered inaudible with this process. No new artifacts are produced either. It detects noises that are present in both the stereo channels in equal strength (actual music will not have that) and removes such components, thereby removing all the noise. This tool can be used as a vocal remover as well. This is a good tool and is a good candidate for trial. No configuration or tweaking is really required.

Mono-a-Mono removes scratches and tape or surface noise from stereo recordings of mono sources. It can be used to enhance digital recordings of old records (whether 78, 45, or 33 rpm, shellac, acetate or vinyl), audio tapes (reel-to-reel or cassette), or even cylinder recordings, provided only that the playback and digitisation of the signal has been performed in stereo, but the original source was mono. It rarely needs any configuration or tweaking. It produces excellent results automatically.
Mono-a-Mono uses a simple muting algorithm to remove the most obvious clicks, and then filters out any components which are not present in both left and right channels. In this way, almost all the audible surface noise can be removed, and even "distortion products" can be made less audible. There are very few cases where any audible artefacts are introduced.
Although designed to process a stereo recording of a mono source, Mono-a-Mono has some features which are especially well-suited to processing old records such as 78 rpm discs and cylinders: it allows bass and treble frequencies to be boosted or cut (to compensate for the different equalisation characteristics used during the recording process) and it has a "click removal" function to reduce the effect of the worst scratches and clicks from old recordings. Two further sliders control simple filters to remove low-frequency rumble/hum and high-frequency hiss.
Mono-a-Mono's ability to separate out different components from within a stereo signal, allows it to also act as a "vocal remover" or "de-mixer", so that tracks can be processed for use in karaoke, or re-mixed with a different arrangement of sources within the sound stage. In this case the original sources must have been mixed in stereo.