- Both spectrum analyzers and oscilloscopes are graph-like tools that display information about a track’s sound
- A spectrum analyzer measures the amount of noise distortion and frequency response
- An oscilloscope measures an analog signal’s voltage.
A spectrum analyzer measures the frequency response and amount of noise distortion, while oscilloscopes deal with dynamics processing, displaying voltage in a waveform, and how it changes across time.
Terms like “spectrum analyzer” and “oscilloscope” can often make us home producers feel like we are discussing something in a chemistry lab rather than making music. I know that when I first started trying to learn about audio tools like this, it made me feel like someone spun me around blindfolded. But don’t worry, it’s not nearly complicated as it sounds!
Both oscilloscopes and spectrum analyzers are essential everyday tools for producers. And while both are visual graphs that assess sound, their applications can differ significantly.
Spectrum Analyzers Explained
Spectrum analyzers are invaluable tools because they allow us to determine whether the signal is within the ideal range or not, as well as where the unwanted frequencies are. It also shows us peak amplitudes, harmonics, and multiple signals at once. This instrument can help you eliminate unwanted sounds that you might not be able to hear, but still muddy up your mix. Spectrum analyzers are extremely helpful when it comes to making decisions about a song’s EQ.
Oscilloscopes Explained
On the other hand, oscilloscopes are more useful when it comes to dynamics processing. This instrument shows voltage in a waveform, and how it changes across time. It allows you to see the attack of each note up close, allowing you to make changes to the compression and fine-tune each individual sonic moment. Oscilloscopes also come in handy when programming synthesizers, as they can be attached to the synth’s output.
Commonalities
Both instruments are used outside of the context of music production since they can be used to analyze a plethora of signals. Here are a couple of examples: Oscilloscopes are used in the medical field for heart monitoring, and spectrum analyzers can be used to test WI-FI.
In both instruments, frequencies will appear in a graph/linear scale, shown along the X-axis, and the amplitude appears on the Y-axis. So, each tool measures amplitude, but what they measure the height against is a different variable.
Both tools also come in a wide range of options and setups. For example, there are four main types of oscilloscopes: DPO, MSO, DSO, and digital sampling. Oscilloscopes were originally analog devices, but the digital oscilloscopes that we have today are complex products with many advantages.
When it comes to spectrum analyzers, some of the most common types you’ll hear about are superheterodyne (or ‘sweep’) analyzers and real-time analyzers like Fourier/FFT analyzers. Sweep analyzers utilize much older technology than real-time analyzers, which are often seen as VST plugins nowadays.
Interestingly enough, nowadays, some tools function as both spectrum analyzers and oscilloscopes, such as MDOs (Mixed Domain Oscilloscopes) made by Tektronix Inc.
Differences
Oscilloscopes were developed nearly 60 years before spectrum analyzers. Oscilloscopes have multiple channels whereas spectrum analyzers only have one. In addition to this, the axis of each graph is based on different variables.
- Oscilloscope=signal/time,
- Spectrum analyzer=signal/frequency.
Oscilloscopes measure the height/amplitude against time, while spectrum analyzers measure amplitude against frequency.
Oscilloscopes are generally easier to get your feet wet with and are more economical, and vice versa. Spectrum analyzers usually take longer to learn the intricacies of, and are usually more expensive.
Price
As you’ve probably already noticed, the price of VST plugins varies widely. In this section, we are going to focus on the price of physical instruments.
Firstly, the price of these tools is largely dependent on bandwidth. From low to medium bandwidths, oscilloscopes tend to be more economical, with many at just $300-$400. But once you get into high-bandwidth, professional instrument territory, oscilloscopes skyrocket in price, going as high as $30,000.
Spectrum analyzers cost roughly $50 for basic beginner tools on the low end and about $6,000 on the high end of things. We’d recommend going with a middle-of-the-road, $2,000-$3,000 model, such as those by Tektronix or Silgent, so you can get the most bang for your buck without breaking the bank.
Pros & Cons
Spectrum analyzers:
| Pros | Cons |
| Can show you harmonics, multiple signals, peak amplitudes, noise floor, harmonics, fundamentals, and more | They are more complex than oscilloscopes and thus more difficult to use |
| They are more accurate |
Oscilloscopes:
| Pros | Cons |
| Their simple layout is easier to learn | They don’t analyze well when other noises are present |
| As a general rule, they are better at real-time bandwidth | They are less accurate |
| They calculate the delay between signals | At high bandwidths, they can be extremely expensive |
FAQ
How Does a Spectrum Analyzer Work?
A Spectrum analyzer measures the total amount of background noise (also known as the noise floor) and the frequency that was played.
When Were These Tools First Developed?
The first oscilloscope was created in the late 1800s by a French physicist named Blondel in order to display voltage. The first spectrum analyzers were swept-tuned and developed in the 1960s in order to measure both known and unknown signals. It wasn’t until 1967 that the first FFT analyzers were created.
Does an FFT = A Spectrum Analyzer?
Spectrum analyzers are not the same thing as an FFT, rather, a spectrum analyzer uses FFT in order to work. FFT is short for ‘fast Fourier transform’ and is a type of algorithm that allows the (time-dependant) signal to be transformed into a frequency.
What Oscilloscopes Do You Recommend for Beginners?
Some of the most popular brands of oscilloscopes include Rigol and Silgent. Of the two, Rigol is the most beginner friendly and economical. Other brands you may want to consider are Hantek, Sainsmart, and Yeapook. Two great entry Level Oscilloscopes include the Rigol DS1054Z and Silgent SDS1202X
What Spectrum Analyzers Plugins Do You Recommend?
Some of the most popular brands of spectrum analyzers plugins include Wavs PAZ and NuGen. Rigol and Silgent also make excellent spectrum analyzers to get you started, including the Rigol DSA832E-TG and Siglent SSA3021X.
Do I Need Both?
While both spectrum analyzers and oscilloscopes assess electrical signals, they can’t both be used for all of the same things. In short, oscilloscopes are cheaper and easier to get a grasp of, whereas spectrum analyzers have a more broad application. Spectrum analyzers aren’t the best choice if you need to analyze wide signals, though. As spectrum analyzer and oscilloscope technology progresses, both instruments have begun overlapping. But,
If you are a self-described audiophile, I would still recommend you get both tools!