Microphones can be a confusing topic. There are many different types, with different polar patterns, shapes and sizes. When I started learning about audio production, I was a clueless about which type of microphone I needed. As my skills and knowledge has progressed over the years, I now know which exact microphone I need for any given purpose. However, it took me a lot of time, research, and experience to get to that point. Luckily for you there are countless resources online to make audio production easier to understand.
I put this website together for that sole purpose. To help others like you, who are in that same situation; and no doubt if you’re here reading this, you’re asking the same questions I did when I began. This article will answer the question ‘what is a large diagram condenser microphone?’ in detail, to make it as clear as possible to understand. First let’s look at what a microphone diaphragm is and why it’s important.
What is a microphone’s diaphragm?
I’m certain you know what a diaphragm is. We all have one. It’s located below the lungs and helps us to breathe by contracting rhythmically and continually. Without it, we couldn’t breathe and singers wouldn’t be able to sing. Yes, our diaphragm is vital for us to function, and a microphone’s diaphragm is just as important for it function correctly.
A microphone’s diaphragm is constructed of a thin membrane that vibrates due to sound pressure variation. This energy passes through the rest of the microphone’s components, which help to convert acoustic energy into electric energy. Without a diaphragm, a microphone wouldn’t be able to function as a transducer.
What is a Large Diaphragm Condenser Microphone?
On condenser microphones, diaphragms can come in two sizes, small and large. As you can see from the diagram the size of the diaphragm directly influences the overall shape, size, and build of the microphone. Small diaphragm condenser microphones are slim and pencil-shaped, whereas large diaphragm condenser microphones are much bigger and rectangular in shape. But what’s the difference and why is it necessary to have two sizes? Apart from just looking different, the size difference of the diaphragm influences microphones’ characteristics and what purpose they’re suited to.
Transient Response
When you hit a drum, pluck a guitar string, or blow a flute, you create an initial high-energy burst of sound know as a transient. Large diaphragm condenser microphones, due to their size, react a bit slower to transients compared to small diaphragm condensers microphones. That doesn’t mean that LDC mics don’t capture audio accurately, but SDC mics tend to have more accuracy and precision. The smaller diaphragm enables them pick up high frequencies that have a smaller waveform exceptionally well. This is why SDC microphones are often used for instruments such as violins, or drum symbols.
Frequency Response
Large diaphragm condenser microphones have a wide frequency range and flat frequency response, usually with boosts in the upper range, with slight roll-offs in the top end. The resulting sound is a pleasing natural presence which makes them ideal for vocals. Large diaphragm condensers microphones are usually considered as having a bright sound; however, this can also come across as harsh depending on how well the microphone has been designed and constructed.
Small diaphragm condenser microphones have an even flatter frequency response than LDC mics, with a larger range, one that can even extend beyond the limits of human beings. I.e. above 20,000 Hz. The flatter frequency response means that SDC mics have a clean and uncoloured sound that is more neutral than an LDC microphone. This makes them perfect for recording a bright sounding instrument, as the higher frequencies won’t be emphasised reducing the chances of a harsh sound. 
Polar Patterns
A polar pattern refers to how a microphone picks up sound. For example, a microphone can pick up sound directly in front of it, from the front and back, and all around it. Polar patterns have different shapes and are suited for different purposes. If you want to read in-depth about polar patterns then please check out my article about polar patterns. The size of a microphone’s diaphragm influences how precise and consistent a polar pattern is.
Large diaphragm condenser microphones have polar patterns that are only fairly consistent, as they suffer from inconsistently across the frequency spectrum. At lower frequencies, the polar pattern becomes wider, whereas at higher frequencies the pattern becomes narrower. Is this a bad thing? Certainly not. Large diaphragm condenser microphones may be less focussed, but they are more forgiving. When a vocalist is singing into an LDC mic, they are able to move around without the sound being significantly changed, in fact the low frequencies remain beautifully lush.
Small diaphragm condensers microphones on the other hand have very concise and consistent polar patterns. The small diaphragm surface area allows for better reliability across the frequency spectrum, as it can pick up little nuisances and transients more easily. For this reason, they are often used in situations where more detail is required.
Noise
It’s important when you record music or audio to keep noise as low as possible. This is where large diaphragm microphones shine more, as they have lower-self noise than small diaphragm condenser microphones. LDC mics traduce more powerful signals, meaning that the signal-to-noise ratio is better than that of SDC mics.
Address Type
Address type refers to where the on-axis angle of the microphone is. Basically, the area of the microphone that captures sound most accurately. Large diaphragm condenser microphones have a capsule that points out of the side, this is known as ‘side address’. Whereas small diaphragm condenser microphones usually have a capsule that points out of the top of the microphone, known as ‘top-address’ or ‘end-address’.
Price
Both the price of small and large diaphragm condenser varies considerably, from a few hundred dollars, to thousands of dollars. In general, SDC mics are cheaper than LDC mics, especially ribbon microphones which are powered by tubes.
Which one is right for you?
The answer really depends on your budget, needs, and what you want to record. Hopefully after reading this article examining ‘what is a large diaphragm condenser microphone?’, you have a clear understanding of their purpose, function, and how they differ from small diaphragm microphones. Now you can make an informed choice and make superb music!
To summarise, large diaphragm condensers microphones are usually brighter, and more forgiving with lower frequencies. LDC mics create a very pleasing sound and help to enrich solo instruments by making them sound more vibrant. Small diaphragm microphones capture sound more consistency and accurately, resulting in a sound that is neutral and uncoloured.
In terms of instruments, small diaphragm condenser microphones are often used for piano, acoustic guitar, stringed instruments, as well some percussion and certain elements of the drum kit. Large diaphragm condenser microphones are frequently used for vocals, acoustic guitar, or for room ambience. Remember though, that there are absolutely no rules in recording. Whatever works, works.
Let me know in the comments what you want to record, and please feel free to ask my any questions.
Chris