Review: Sennheiser MD 421 Kompakt
An old head on a new body. The Sennheiser MD 421-II has a sibling, the MD 421 Kompakt.
By Mark Woods
18 October 2024
First released in 1960, the MD 421 is one of the great dynamic mics, and Sennheiser’s best known product with more than 500,000 sold to date. A good example of getting it right the first time, the 30Hz–17kHz frequency response and clear sound made it suitable for broadcast and recording, while the cardioid polar pattern, high level handling and rugged construction made it popular for speech and then live music.
Still made in Germany, it has remained largely unaltered since the original MD 421 but there have been changes in the materials and engineering over the decades as technology has advanced. In 1998 the MD421-II was released with a handful of subtle physical changes and slightly updated sound due to improvements in manufacturing.
SOMETHING FRESH
Now, the MD 421 Kompakt has the same capsule and basket we know and love, but the truncated body is new. Developed well before modern CAD, the original MD 421 was a complex design that addressed several issues successfully – directional control was achieved without entry ports behind the diaphragm so it could be handheld without affecting the sound. The tight cardioid polar pattern and controlled low frequency response was the result of intricate internal components, including chambers, tubes and damping; a bass pre-emphasis tube from the capsule to the mic body; and four rear ports.
At first glance it appears there’s not enough space for those parts to fit inside the Kompakt, which would imply a significant change to the original design, but no, all of the above MD 421 design features are retained. The space saving comes from losing the variable LF roll-off switch. This five-position rotary switch has been a handy feature of the MD 421 since the beginning but it’s not a dealbreaker – channel EQ is a lot more comprehensive now than when the 421 was first designed and it makes the mic a better size for most applications. I mean, you can hide a short drummer behind a regular 215mm-long MD 421-II above a rack tom, while I can now see some of their face over the 122mm-long Kompakt!
SLIM LINE
The weight saving is also significant, especially for mounting on toms – 385g for the MD 421-II is too heavy to rim-mount, 159gm for the Kompakt is okay. Although the mic is surprisingly light to hold, the glass composite shell feels tough. The hardened stainless-steel basket is also strong but does provide a fairly large target for drummers (enough for me to be anxious). Old 421s with banged up baskets are a common sight; they still seem to work okay but look a little sad.
The only thing Sennheiser didn’t get quite right back in the day was the neat but flawed clip-in standmount. The design was improved for the MD 421-II, but they could still break or get lost too easily. I’ve seen them gaffed to mic stands in studios but that’s not a great look on a live stage. The new MD 421 Kompakt has the standmount built into the mic body. Problem solved.
NEED TO KNOW
Sennheiser MD 421 Kompakt
Dynamic Microphone
DRUM VERSION
The Kompakt can be purchased as a drum version that includes the MZH drum mount. Also available separately, the MZH is a simple but effective universal mount that can be used with any mic. It has a 3/8-inch thread so an adaptor may be needed, the captive standmount on the Kompakt accepts both 5/8- and 3/8-inch threads. The MZH snaps over the drum rim and holds the Kompakt in just the right place however close or far you want it from the drum.
You can hide a short drummer behind a regular 215mm-long MD421-II above a rack tom, I can see some of their face over the 122mm-long Kompakt!
COMPARISONS
My first impression talking into the Kompakt is that it’s got that MD 421 sound. In a direct comparison, speaking into a variety of common mics, it stands out for its appealing, full sound that’s warm and clear up-close. It sounds like the radio. The MD 421-II is variously liked and criticised for a modest but broad presence peak compared to the original and the Kompakt has it too. The cardioid polar pattern has a wide sweetspot in front of the mic, the off-axis response is somewhat woolly in the low frequencies but there’s good rejection from the rear.
I took the Kompakt to Sound Recordings near Castlemaine, where studio owner Alex Bennett records and mixes to tape (so he can be trusted), and he has a couple of original MD 421s. Side by side, the mic body size difference is significant. (His black one is an example of what the old clips can do, beside it is a replacement someone made on a 3D printer.) We compared the sound of the Kompakt to his oldies and it had a little less low frequency level and a whole lot more handling noise, but they were much the same sound overall – the Kompakt a little brighter and more modern than the originals. I’ve read that 421s lose lows as they age, it might be true, but it wasn’t enough to matter, they’re still good mics.
IN THE WILD
The MD421 Kompakt could be a vocal mic on a stand but it’s not a handheld vocal mic. The built-in clip makes it awkward to hold and, as mentioned, it has high handling noise compared to the 421s. Instruments are what it’s best at – drums, of course, if you’re game but I prefer less risky applications. It excels on guitar cabs. I had a good opportunity to compare it at Chopped Rod & Custom this year – it has the loudest bands; they want the guitars cranked in the wedges; and they need to be loud in the PA too. The Kompakt was consistently the best sound out of our pool of the usual SM57s and e906s – unfazed by volume with the clearest low-mids, and most natural hi-mids, was the crew consensus.
The multi-purpose Kompakt is also a natural for horns – the full sound is great for saxes or trombones particularly. Percussion too, modern condensers will have more HF detail for the sizzly bits but for congas etc the Kompakt is ideal.
WELCOME ADDITION
The MD421 Kompakt is a welcome addition to the Sennheiser family. It will sell alongside the MD421-II, its new body bringing some fresh energy to a famous model. The Sennheiser MD421 has always been premium product but its sound quality and longevity go beyond mere price. The good news here is the Kompakt is a fair bit cheaper than the MD421-II and considering you get the same sound, a new standmount, a size advantage for most applications, and the option of the MZH drum mount, it’s great value.
This is so amazing! I was literally thinking to myself 2 days ago, ‘I wonder if there is an equivalent MD421 that I can clip on my Tom’s for recording’, and here it is! Thanks for the review
An interesting development, and potentially beneficial for tight spaces. However, the channel EQ is not a substitute for a roll-off at the mic itself, that presents the desired signal to the mic pre passively.
I love my EV 408a’s.
Do you think I would dig these? I am very open minded and just looking forward.
Tom Vasilarakos @ Northern Sound