This article intended to be more of a philosophical discussion than a technical review. When you are dealing with Ham Radio transmitters and receivers, your choice of microphone can be based on science or opinion or both. There's no real right or wrong answer. It's kind of like asking someone how to adjust bass and treble controls on a music system. Let's start with some technical background.
The Electro-Voice RE27 N/D is a professional-grade studio and broadcast microphone designed to deliver exceptional clarity, sensitivity, and sound fidelity. Its key features include a powerful neodymium magnet and a reinforced diaphragm dome, providing increased sensitivity—up to 6 dB more output—along with clean, undistorted performance at high sound-pressure levels and an extended high-frequency response.
The RE27 N/D also features a presence rise around 5 kHz, adding clarity and definition to the voice. Some argue that the same effect can be achieved with an equalizer. That's certainly true, but there's something to be said for having that tonal character built directly into the microphone's response, right from the start.
As a large-diaphragm, cardioid dynamic microphone, the RE27 N/D delivers sound quality that rivals many of the best condenser microphones. Unlike condenser microphones, its dynamic design makes it well suited to close-miking and high sound-pressure levels. Its Variable-D design also minimizes the proximity effect—the increase in bass response that typically occurs as a speaker moves closer to a microphone.
For some radio personalities, however, the proximity effect is a desirable feature rather than a drawback. It's often heard on evening programs when hosts adopt an intimate, close-miked style sometimes described as pillow talk, giving their voices a deeper, warmer sound. The RE27 N/D's Variable-D design helps maintain a more consistent tonal balance as the speaker moves closer to or farther away from the microphone.
Another advantage is its hum-bucking coil, which helps reduce electromagnetic interference—a particularly useful feature in radio studios and other environments filled with transmitting equipment. Combined with its excellent off-axis response, this makes the RE27 N/D a compelling choice for broadcasters seeking clear, consistent, and dependable voice reproduction.
The RE27 has three with switches near the base of the mic to control frequency response. With all switches off (switched up towards the head) the response is set to flat from 80-2,000 Hz with a 6-dB rise in response from 2,000-16,000 Hz. With one filter switch in the “roll-off” position (down), low-frequency response tilts down 6 dB from 250 to 100 Hz. A second filter switch, when in the “roll-off” position (down), creates a gentle roll-off of 12 dB from 1,000 to 100 Hz. The third filter switch, when in the “roll-off” position (down) reduces the high-frequency rise by 3 dB.
The mic has a built-in blast and wind filter and a built-in shock mount. It is unclear how effective these are. I suspect they are better than nothing but not perfect. I have seen applications that have external pop filters but have never seen foam wind screens on this mic. My own application uses the Electro-Voice 309A shock mount suspension. The mic has a balanced 150 ohm output through a standard XLR connector.
This mic is expensive. It lists for $499 almost everywhere. Used ones are typically found between $400 and $450. It comes with a carrying case and a stand clamp. The mic is large and heavy, It weighs around 1.5 pounds. The 309A shock mount suspension adds another $99 and adds almost another pound to the weight. I have seen professional studios with and without the shock mount so it is unclear if it is really necessary. The shock mount adds another 7.5 inches to the distance between the mic clamp and the stand threads. That means the shock mount would either raise the mic 7.5 inches above the top of your desk stand or lower the mic 7.5 inches below the bottom of your dropdown boom mount.
If you use the provided mic clamp, you should know that it clamps to the rear of the mic. This means that the mic will be front-heavy on the stand. Most of the body of the mic has acoustic screens so you can't use a shock mount that clamps to the body of the mic without blocking the ports. The rear body area has a small portion of solid space but the mic will still be front-heavy. The 309A shock mount allows the mass of the mic to be centered and balanced on the stand mounting point.
If you decide to use a boom arm for the RE27 you need to consider the weight of the mic along with the shock mount.
RE27 Microphone Weight: 709 g / 1 lb 9 oz
309A Shock Mount: 312 g / 11 oz
Total weight: 1.02 kg / 2 lb 8 oz
I originally used a very inexpensive boom arm. I had to increase the spring tension on both sections of the arms. I did this by moving one end of each spring to a more distant mounting point. This required using an existing hole and drilling a new hole.
When using the 309A shock mount, the mic can hang somewhat low on a boom arm. In order to raise the mic I used an existing hole in the bracket and drilled a new hole on the other side.
This allowed me to raise the mic within the hanging frame. If you were using the 309A on a desk stand, the mic might be too high off the desk. You can use this alteration to lower the mic.
Click Here for the RE27 N/D Mic Data Sheet
Click Here for the 309A Shock Mount Data Sheet
Now, on to the philosophical discussion. Many of my opinions are formed by two great veteran ham radio operators. One is Clark, N1BCG, who is a long-time broadcast engineer and Ham Radio AM expert. The other is Rob, W1AEX, who is a long-time Ham Radio AM expert, SDR expert, and online resource. Both have been invaluable consultants and trusted advisors.
I believe you should strive to deliver the finest possible audio quality to your transmitter. The challenge is that transmitters and receivers vary considerably in their capabilities, and that can limit what listeners actually hear.
Modern transceivers from manufacturers such as Kenwood, Icom, and Yaesu deliberately restrict transmit audio bandwidth. In some cases, the limit may be as narrow as 2.4 kHz or even less for SSB. These restrictions help create courteous, “good-neighbor” signals that use spectrum efficiently and minimize interference when the audio is properly adjusted.
On the other hand, some hams still use vintage equipment, including radios that originally entered service during World War II. Much of this equipment has never been modified to improve its audio performance. Its receivers may lack high-fidelity audio reproduction, and its transmitters may be incapable of delivering full-fidelity audio. Consequently, many of these operators probably wouldn't hear a significant difference between your RE27 microphone and almost any decent entry-level microphone. Even the factory hand microphone supplied with the Icom IC-7300 sounds remarkably good to many listeners.
So why spend the money on a microphone like the Electro-Voice RE27 N/D if most people won't notice the difference?
My answer remains the same: I believe you should strive to deliver the finest possible audio quality to your transmitter.
My primary transceiver is the Apache Labs ANAN-G2, a software-defined radio (SDR) in which operating parameters are controlled through software. This gives me considerable flexibility in configuring the transmit audio bandwidth to take advantage of the rich, detailed sound the RE27 can deliver. I can enjoy that fidelity while still operating as a good neighbor by keeping my transmitted signal within the bandwidth I have selected.
Of course, the limitations at the receiving end remain. Other operators have different radios, receivers, speakers, and audio settings, so they won't all hear the same level of fidelity. At least I know that, at my end, I'm doing everything possible to deliver the best audio my equipment can provide.
The real pleasure comes when both operators have the equipment and bandwidth to enjoy high-fidelity audio. This approach isn't intended for weak-signal work or for chasing distant contacts under difficult conditions. It's about having an enjoyable conversation with another operator and appreciating the quality of the audio along the way.
Yes, a high-fidelity SSB signal can occupy more bandwidth than the narrower signals used by many modern transceivers. But with a properly configured SDR, the transmitted signal can remain clean and controlled, without unnecessary splatter into adjacent channels. Even with SSB bandwidth set to 3.8 kHz, the resulting audio can sound amazing when both stations are equipped to take advantage of it.
Microphone comparisons have included the Shure SM7B, Heil PR 40, Audio-Technica AT2020, Behringer B-1, and Behringer XM8500 Ultravoice. Test results have not produced a clear winner across the board, which is hardly surprising. Microphone preference is subjective, and the results depend on the speaker's voice, microphone placement, processing, and listening conditions. A microphone that sounds excellent with one voice may be less impressive with another.
One characteristic worth considering is the **proximity effect**. With directional microphones, bass response generally increases as the speaker moves closer to the microphone. This can produce a fuller, deeper voice, but it can also make the sound inconsistent if the speaker continually changes position.
Proximity effect has long been used deliberately in broadcasting. Some male radio announcers, particularly those associated with late-night easy-listening programs sometimes described as “Pillow Talk,” cultivated a deep, intimate vocal sound. By speaking very close to the microphone, they could create the impression that they were talking directly into the listener's ear. The Shure SM7B, with its broadcast heritage and ability to produce that intimate sound, became a popular choice for this style of presentation.
Ultimately, choosing a microphone is about more than selecting the model that wins a comparison test. It's about finding the microphone that best suits your voice and your goals. For me, the RE27 is part of a broader philosophy: Start with the best audio you can produce, configure your transmitter responsibly, and let the receiving station's capabilities determine how much of that fidelity can be enjoyed.
Some people prefer the RE27's brothers. Those are the RE20 and RE320. These three mics share the same body and look almost identical.
The RE-20 is considered a classic mic. It has the flattest frequency response of all three which provides a natural sound. However, the RE-20 has the lowest output and needs more gain. All three Electro-Voice mics use their Variable-D technology which reduces the proximity effect. This minimizes bassiness when close-talking.
The RE320 has a slight bass boost of 1dB between 150 & 250 Hz. Then has a mostly flat midrange followed by a 5dB treble boost from 3.5kHz to 10kHz. Then it's flat to 3-15kHz. The RE-320 Sits between the RE-20 and RE-27. It has a bass boost and a significant presence boost and sounds similar to RE-27. It has a hotter output than RE-20 because of its Neodymium element and incorporates the Variable-D technology.
The RE27 has a flat bass and mid section but has a significant boost beginning at 1kHz peaking at 5dB around 4kHz. Then it starts to gradually roll off from 8kHz to 20kHz. This mic is more sensitive than the other two producing more output signal (6db more) for the same acoustic input. It has three builtin filters selectable wirh switches accessible at the base of the mic. Low cut, mid cut and high cut. It has a Neodymium magnet and Variable-D technology. In the name RE27 N/D the N/D stands for Neodymium which is a very powerful magnet.
The RE27 has what is called a presence rise. That is the boost in the treble. That makes this mic sound bright compared to the other two.
Many people are fond of the Behringer XM8500. The Behringer XM8500 Ultravoice often sells for under $30. Music vocalists say the XM8500 sounds as good as the industry standard Sure SM58 which goes for about $100. If you want a great dynamic mic that won't break the bank, the Behringer XM8500 is an excellent choice. Another popular mic is the MXL BCD-1 manufactured by MXL, a division of Marshall Electronics, located in California. This is a dynamic broadcast mic. It comes with a windscreen and internal shock mount. It retails for about $150 but I saw it on Amazon for $75 so look around.
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| Shure SM7B $400 |
Heil PR-40 $350 |
Audio Technica AT-2020 $80 |
Behringer XM8500 under $30 |
MXL BCD-1 $75 |
Behringer B-1 $99 |
Here is a comprehensive ratings list of many microphones on E-Ham.
Just a word of caution if you are interested in the Shure SM7B. I was recently looking at them on Amazon out of curiosity. The price was about $359. Then a couple of them for about $99 caught my eye! They were obviously fakes. The mics and the listings did not have any Shure branding but they looked identical to the SM7B. The seller had some rediculously long name who was based in China. I recently saw many SM7B mics on Ebay. Those prices were rediculously low in the $130 range. Many sellers of fake mics use stock photos so the ads look like real Shure products. Once famous podcasters started using SM7B mics the counterfeiters saw the opportunity to sell fake SM7B mics to the unsuspecting novice who wanted to be famous. If you don't want to go wrong purchasing an expensive mic be sure to use a reputable dealer such as Sweetwater or the other well-known musician outlets.
Using the RE-27 with my Anan-G2 I found that I needed to apply equalization. The RE-27 was very heavy in the low end. I had to reduce the gain from 50 Hz through about 800 Hz especially when setting up the SSB profiles. I did this with the CFC and not with the equalizer. When adjusted correctly, my voice appeared to create RF energy on the spectrum display that looked mostly flat across the transmitter bandwidth. For AM, I adjusted for slightly more bass and a little presence rise in the treble.
Don't get the Electro-Voice RE27 unless you have a transmitter that is capable of showcasing its fidelity. If you get the Electro-Voice RE27 don't be disappointed if goes unnoticed on the air. You can't go wrong with the RE27 as a very high quality, best-in-class mic. That doesn't mean it will be right for you or your equipment.
Does the RE27 need a foam windscreen? The RE27 has good built-in pop filtering. The official Electro-Voice WSPL-2 Foam Windscreen is recommended to reduce plosives (popping sounds from P and B), breath noise, and other wind noise, especially for close-miked vocals and live applications such as in Ham Radio. The RE27's internal design already includes some level of pop filtering, but the WSPL-2 provides significant additional protection and is considered a worthwhile accessory for optimal sound quality. I found the WSPL-2 to be rather fat and unsightly. I settled on a windscreen designed for the AT-2020. Not all foam material is the same. I found an aftermarket screen that had a smaller outside diameter, provided effective pop filtering and did not reduce or muffle the high frequencies.
Update 02-28-2024 - Thetis software now supports ASIO
I decided to change the audio configuration to take advantage of cmASIO for using Thetis with the ANAN Transceiver. Audio Stream Input/Output (ASIO) is a computer sound card driver specified by Steinberg. Steinberg has been a leader in music writing, recording, arranging and editing software and hardware. Most recently the company was acquired by Yamaha. The ASIO driver proviodes a low-latency and high fidelity interface between a software application and a computer's sound card. The "cm" part of the term cmASIO refers to ASIO support for Thetis built into the supporting the Thetis ChannelMaster module (ChannelMaster.dll).
I purchased a Behringer UMC204HD USB Audio interface for the computer. This is sometimes called a "sound card" because the original computer sound devices were actually circuit board cards that plugged into the computer motherboard.
The later versions of Thetis have cmASIO capability. This allows Thetis receiver and transmitter audio to directly interface with the computer bypassing other Windows drivers that could impact quality and latency. Using the UMC204HD I was able to eliminate all audio cables between the ANAN and the PC while maintaining high quality, low latency audio paths that transport digitally over the ethernet cable.
This model has two mic inputs. I only needed one input but this model had Inserts Jacks on the rear panel.
I have the RE27 mic as my desk mic. I like to use this mic as the computer mic as well as as the mic for transceivers. Using the Inserts Jack I can extract line level mic audio and feed it to other radios. The Insert Jack is intended to "insert" external equipment into the audio path. Recording engineers like to insert processing equipment such as compressors, expanders and other broadcast processors. When you insert the plug, the audio chain is broken and the separate Input and Output sigals are available through the jack. Since I did not want to break the chain but just tap into it, I simply connected the Output right back to the Input and tapped into it. This allowed me to send unprocessed line level mic audio to the other radios.
One concern was that the RE27 mic output voltage was so low that it required the mic gain to be set high. This introduced a bit of extra noise and made the mic input more susceptable to RFI under certain conditions. I decided to add the Cloutlifter CL-1 preamp between the mic and the sound card. Cloudlifters provide more signal from the microphone itself, allowing the sound card preamp to operate in its optimal gain range. This also reduces noise and improves the natural frequency response of the mic by allowing the preamp or interface to operate within its comfort zone. The Cloudlifter uses +48v Phantom Power, but does not pass power to the mic.
Notes on using ASIO with Thetis
When using Thetis. the ASIO-enabled ChannelMaster (cmASIO) is a high-performance feature targeted for ‘power users’ wishing to permanently sink/source their speaker/microphone audio streams via an ASIO sound device attached to the host SDR computer, when operating phone or CW. When implemented by the user, all audio streams normally processed by the audio codec chip in the radio are thereafter processed by the external ASIO device instead. Under these conditions, VAC1 & VAC2 may then be dedicated to digital-mode operations without the worry of having to frequently switch back and forth to phone or CW.
Once cmASIO is enabled, the ChannelMaster expects to enjoy exclusive use of the selected ASIO sound device. This conforms to Steinberg Audio SDK specifications and helps guarantee the highest performance available. Therefore VAC1 & VAC2 will not be able to select the particular ASIO driver in use by the ChannelMaster.
In Summary
Is the RE-27 possibly the finest microphone ever made? Possibly. Do you need it? Probably not. If you get it, will your world be changed? Probably not. Will you like it? Most probably. Is it worth the cost for Ham Radio use? Perhaps the answer is subjective. Is it worth it to you?