For more than 10 years the 40 series from Audio Technica has been a benchmark for large-diaphragm professional condenser microphones. The AT4033 is a classic and is well known for being reliable, hard-working, and able to return excellent sound from a large variety of sources.
Other well known and respected mics from the 40’s are the AT4050 with its switchable-patter, the valve-based AT 4060, and the AT4047 who’s capsule that has a true externally-biased capacitor and a transformer coupled output. This differs from the 4033 which has an electric capsule and not transformer in the circuity.
The reason for this little history lesson is to highlight the fact that the AT4040’s price and technology is actually a mix between the 4047 and 4033. This creates a fairly unique little microphone with some interesting features.
Like the AT4047, the AT4040 is a fixed cardioid-patter. It uses a large diaphragm capacitor capsule that is externally-biased. However, like the AT4033a, it actually has transformerless circuitry. The capsule is 1 inch and uses a gold-sputtered and precisely tensioned diaphragm. This produces a very natural and smooth-as-butter “sonic characteristic”. Thanks to the surface mounted preamp you get a wide dynamic range with very low noise and great SPL abilities. In fact the specs say that you get a max SPL of 145dB, with a dynamic range of 133dB. The AT4033a’s noise floor is a little higher and is a couple dB’s higher than the available quietest mics, but it is more than enough for any of this mics intended uses.
Like most mics in this class, you will need to get a standard 48V power supply that at 1pa gives you a nominal output of 25mV.
When you recieve your AT4040 you will find that they shipped it in a large cardboard box containing a foam case, and is viny-wrapped. Also included in the box is the AT8449 elastic shockmount.
Design & Construction
The AT4040 comes in at just over .75 lbs and is the lights of the 40-series from Audio Technica. The actual design and look of the mic is very similar to the other mics in the series. The body is nickle painted and painted black. The mesh grill found on the front and back of the capsule is dual layered. It’s fairly large, making up for over half of the mics height. Audio Technica claims that the extra large volume that is enclosed in the housing minimizes all of the internal reflections that can have a negative impact on your sound.
On the mic’s front you will find the AT emblem. On the back of the base are a couple of slide switches. They are made of white plastic and are just about flush to the base. The right slider gives you a 10dB pre-attenuator. The left slider allows you to turn on a high-pass, first-order filter that turns over at 80 Hz.
There is a kind of “stalk” sticking you from the bottom of the mic where the XLR connection is. Inside of that connection you will also find the serial number printed on a little lable. It was a pleasant surprise to find that a serial number was included. I feel they are an important security feature on expensive equipment, and a lot of companies don’t issue individual serial numbers anymore.
I found that this mic was fairly sensitive when handling it and produced a fair amount of noise. Fortunately a pretty good shockmount is included that worked very well for isolating any mechanical vibrations and noise. It was a little difficult actually attaching the mic to the mount though. The bottom of the shockmount inhibits your ability to fit an elastic band around the bottom of the mic. Once I finally got it on though it felt very secure and fit tightly.
To attach it to a standard stand it is threaded for 58 inch, though a 38 inch insert is included to attach to European stands.
Audio Technica’s website gives you a fairly comprehensive breakdown of all the technical aspects of the AT 4040. Included with this information is a frequency-response play and a polar response chart, though I can’t think of a reason for the polar response one. AT says that the frequency response is extremely flat. Falling between 20Hz and 4kHz. Between 6.5kHz and 11kHz you will see some substantial response peaks, getting up to a maximum of about 5dB. The same peaks are found on the AT4033a and SE mics, though not as extreme. In my opinion, these findings are due to the housing and capsule design characteristics.
At around 16kHz the high-end rolls off pretty quick. AT says that the overall response goes all the way between 20Hz and 20kHz, but there’s no way my hears can hear anything that high. According to the published material the polar response at 1kHz is the classic cardioid response. The polar response is not given for other frequencies.
The sound from the AT4040 is similar to the other 40 series. The bottom end is pretty warm with a good amount of crisp detail. Very quiet and clean. There is a clear rear lobe that develops as the frequency increases, as is found in a regular hyper-cardioid pattern polar response. The polar pattern opens out quite a bit as the frequency lowers. It becomes more omni-directional and moves to the mic’s sides, causing the sound to be less bright, but fuller. The mid and high end loose sensitivity, with the low end retaining its sensitivity. This is a normal and expected quality that can be used advantageously with using the mic close to the source, and making slight changes to the mics position to get the perfect sound quality you’re looking for.
I placed the AT 4040 close to a grand piano and found that it worked very well. It gave great transient details and provided excellent weight. I also had great results when using it on percussion instruments and on acoustic guitars. Vocal recordings sounded great, even better than on the more expensive Neumann TLM 103 I was using. Vocal results may be variable based on the voice character though, so I can’t say one was objectively better than the other. The only problem was that the 4040 did tend to allow more mechanical noise that the Neumann.
Here is a great video from Audio Technica explaining how to get a great sound out of this mic:
At this price level the AT4040 SM microphone is a great choice. It is equipped very well compared to other mics in its price point like the Rode NT1 or the AKG C3000, and is certainly a strong contender if you are thinking about investing in a quality microphone.