Windows 7 - Vinyl restoration help for Sony Sound Forge 10.0

Hi, i recently started restoring all the vinyl records i have. im currently using sony sound forge 10.0.... using this im able to eliminate all the clicks and crackles... but there's a deep bass hum which i wish to filter but i cant do so without filtering the bass in the song as well.... any suggestions???

Is the low hum on the recordings or is it a "ground loop" hum? If you connect whatever external device you have connected to the PC, such as a stereo system output, RIAA preamp (you can't connect the turntable direct unless it has a built in RIAA preamplifier and most do not) with no record playing do you her the low hum? If you do its a ground loop hum and you need to correct that. Ground loop hums are common with guitar amps and AC powered effects and the "quick and dirty" way to fix it is to lift the AC power ground on one device.

One other condsideration, the interconnecting cable between the external device and the PC audio input. It must be a shielded audio cable. If you use a "speaker" cable it is unshielded and AC hum can be picked up.

On the other hand if you are connecting a turntable, that does not have a built in RIAA preamp, direct to the PC that is probably some (if not all) the problem. First the output from the turntable needle is too low for a PC input, second you need the RIAA preamp to recover the full fidelity of the recording.

Iv connected a turntable (Garrard 6. 200 C) to the auxilary input of my sound card. as far as im aware it does not have a built in RIAA preamp. all connections from the turntable to the PC are done using shielded wires. i feel that the hum is from the recording but im not too sure.. how do i figure out what is the exact source of the hum?? and how do i correct it

Some things to investigate: I'd think you must use a proper preamp (to get both the needed eq correction and impedance), missing wiring shield, shield(ground)\signal wires swapped, missing ground, ground loop.

If it turns out that the hum is in your original recordings and cannot otherwise be corrected, you can investigate a "notch filter" that is tuned to eliminate the frequency of your particular hum, with minimal effect on bass generally.

I think there are some notch filters available for Audacity, the highly regarded free audio recorder/editor. They are "plug-ins" that you probably will have to locate and download separately. I think the Audacity filter files are written in "Nyquist" and typically have an ny extension.

Re RIAA preamp: you can buy an external Behringer UFO-202 USB soundcard for $35 that includes an RIAA pre-amp and a turntable connection. This allows you to connect a turntable directly to a PC without using a standard home stereo amp or receiver, while still providing proper RIAA equalization.

I just opened Audacity and looked at the menu choices under the "effect" menu.

One of the choices is notch filter, so apparently it is built in to Audacity and you don't need a plug-in. At least, I can't recall downloading a separate notch filter.

The filter is adjustable by slider to allow you to set the frequency it will attack.

The second slider adjusts the width of the "notch". Higher values make the notch narrower and would presumably reduce the effect on nearby frequencies.

I can't say how well it works.

There may well be other "Nyquist" plug-ins that can be downloaded and added to Audacity. I know I have downloaded one that acts as a general "tone" filter that can be used to brighten up the treble a bit if desired.

Here is a pic of the notch filter.

As I mentioned, just connect and turn on the turntable, without any record on it and see if you hear hum in the PC's speakers. However, as I previously mentioned the output of the turntable is very low and you have to run the PC's Line In volume control at max to even get any signal and that can amplifiy all sorts of line noises.

Turntables (most) also have a separate ground wire to attach to a ground on the device it's attached to and that will also help with hum.

Here are the various Nyquist plug-ins currently available for Audacity.

Audacity: Download Nyquist Plug-Ins

They need to be downloaded and placed in the installed Audacity's "plug-in" folder.

@firebed.. i turned up the volume to maximum without any record playing and i do hear a hum in the speakers.. what do i do??

Is this hum the same as what you hear in recordings?

How loud do you have to set the PC sound before you start hearing the hum. With nothing physically connected to the PC do you get the same hum? Just trying to isolate where it is or or where it's coming from.

If it's coming from the turntable, most have a separate ground wire that you connect to a ground on the device you have it connected to. If you have that, connect the ground and see if it makes any difference.