TAPE MACHINES: HOW THE IPS AFFECTS THE SOUND
Today I would like to talk about one of the main parameters that affect the sound when using a tape machine (reel-to-reel). The IPS (Inch Per Second). But what is it? How does it change the sound? And most important what are the best applications?
First of all, we have to say that many elements can affect the sound of a recording when using a tape machine. Some of these elements are the reel-to-reel quality, heads, formula and the size of the tape, BIAS, alignment, etc. In this tutorial, we want to give some general indications of how the IPS affects the sound (both on real machines and plugin emulations).
Tape Machines Glossary
To better understand the topic of this article, I've put down the definition of some common words used when talking about tape machines. IPS: (Inches Per Second): is the speed at which the tape is moving across the tape head on the recorder. And it's the subject of this article.
WOW AND FLUTTER FX: Are caused by irregularities in tape drive speed during the recording or reproduction. The wow effect is recognized aurally as pitch fluctuations and affects more the low frequencies. Flutters are called those irregularities that affect the higher frequencies and cause a roughening of the tone.
Before starting I would like to do some consideration regarding the use of reel-to-reels. In the past, the tape was the only support available to record an album (look at it as an old version of your favorite DAW). The effort of the manufacturers was to eliminate as many side effects as possible (hiss, saturation, "color", wow and flutter, etc.) to achieve the most pristine sound possible. Nowadays, with the development of digital technology, we have achieved that pristine sound, only to realize that we are in love with those tape nuances. So, while there are still people who like to use the tape for recording (most of the time alongside ProTools) or to bounce the mix on it, some others look at the tape as a mere saturation machine. Nothing wrong with this.
Often it might seem like we want to use tape only for its typical saturation, but there are much more exciting aspects that a reel-to-reel brings to the table. One is the smooth roll-off on the top end. Another one is the magic glue and dimension of the sound that some tape machines can create. I have also to say that usually, you can push a hardware machine much further than a plug-in. On the other hand, plug-ins have the advantages of being much cheaper, they don't need any maintenance and they don't introduce any hiss. I would like also to flag that this is not a war between the two technologies, there are pros and cons in using both of them. Alongside my reel-to-reel, I have a decent collection of tape emulation plug-ins (at the end of this article I suggest you some). That said, in this article, I talk about real tape machines in good working condition and well-aligned.
Let's have a look at the IPS:
3.75 IPS: This kind of speed is usually found in home recorders and is considered Lo-Fi. As a characteristic, this speed tends to darken the sound and boost the low end. Commonly, it's not used in recording studios unless experimenting with Lo-Fi saturation. This kind of machine can introduce some notable hiss and wow and flutter fx.
7.5 IPS: You could find this kind of speed in old home studio recorders. For most of the pro studio applications, this speed is considered low quality, but it can be used successfully on instruments such as kick or bass as it tends to boost the low end giving a nice bump. At this speed (depending on the tape recorder) you might have some wow and flutter fx and some notable hiss.
15 IPS You can find this speed in studios and home studios' tape recorders. This speed introduces the typical tape saturation (tape compression), especially if you drive the input hitting the tape harder. The 15 IPS speed also tends to eliminate some digital harshness. I use this speed to bounce to tape my mixes when it suits the vibe of the song. At this IPS the machine may introduce some hiss.
30 IPS Usually, only a studio tape recorder works at this speed. It has a good high-frequency response and can be used both for mixing and mastering applications. It tends to have a clean sound (less hiss) with less distortion/saturation and more dynamic range.
(I'll try to keep this list updated)
If you are looking for some tape machine emulation we suggest to try:
Slate Digital VTM
IK-Multimedia Tape Machine 440, 80, 99, 24
Waves J37, Kramer Master Tape
If you are looking for a real tape machine you might be interested in the following brands: