Sennheiser MD 504
A 60-gram cardioid that Sennheiser built to survive the road and marketed as the mic that would change how you place a mic.
Overview
Sixty grams. Thirty-three millimeters across, fifty-nine millimeters long. The MD 504 is a dynamic cardioid small enough to lose in a jacket pocket, and that small size is the whole design argument. Sennheiser's own literature pitches it as a special microphone for recording instruments. The German-language sheet is blunter about the intent: it's built to be "gut positionierbar durch geringe Baugröße," easy to place precisely because there's so little of it to place. Anyone who has spent twenty minutes fighting a full-size dynamic into a tight spot over a snare or inside a kick drum will see the point.
The capsule is a pressure-gradient receiver, the standard cardioid dynamic arrangement. Transmission range is 40 to 18,000 Hz. Field open-circuit sensitivity is 1.8 mV/Pa at 1 kHz (±3 dB, which Sennheiser also expresses as -55 dBV). Nominal impedance is 350 Ω, with a minimum terminating impedance of 1000 Ω. Those are unremarkable numbers on paper, and that's fine. The MD 504 was never sold as a measurement instrument. It was sold as a tool. The manual's feature list reads like a tour manager wrote it: extremely robust, high-pressure sound with powerful bass, small size for easy positioning, and the claim that the highest sound pressure is transmitted without distortion. Sennheiser's own advertising in the trade press billed it as "this little wonder" that "will change the way you mic," which is marketing, not a verdict.
Connection is a three-pin XLR-3 (Canon) plug. The package included the microphone with a stand-fixing bracket and a pouch. A StageHand quick-change clamp was offered as an accessory but not included, which matters if you're buying used and wondering why the clamp isn't in the box. The manual is dated 03/94, which puts the documentation at the tail end of the ProForce-era push. Mix (1994, p.40) ran the MD 504 alongside the MD 511/512 and MD 515/516 in the same ProForce family advertising, positioning it as the small-format option in a lineup built around durability and gain-before-feedback.
What the mic actually sounds like is where the period press gets interesting. Studio Sound (April 1995, p.40) ran a full review by Dave Foister under the headline "MD504 — too small to miss?", and the takeaway was that the sound is "remarkably big and complete," with fullness and resonance never sacrificed despite the tiny body. That's the tension at the heart of this microphone: a 60-gram object that doesn't sound like one. The Spanish-language sheet makes the same point in its own feature list, describing an expressive sound with bass emphasis. EQ Magazine (October 1994, p.97) noted the cardioid pickup pattern and that the design was intended to withstand the toughest road-tour conditions, which lines up with the "extremely robust" claim repeated across every language version of the manual.
Collectors and working engineers tend to meet the MD 504 in two places: as a compact instrument mic for drums and amps, and as an oddity in the Sennheiser dynamic line that never reached the ubiquity of the larger broadcast and vocal models. EQ Magazine (October 1995, p.20) listed it in a microphone roundup at a price of $109, categorized as a dynamic cardioid. That's a modest figure, and it explains why so many were bought to be abused. Surviving examples are often cosmetically rough. There's very little inside a pressure-gradient dynamic to break: no phantom power, no active electronics, no capsule bias supply.
Practical notes come mostly from the documentation rather than from any failure pattern. The 1000 Ω minimum terminating impedance is worth respecting. A preamp that presents a much lower load will cost you output and shift the response. The stand-fixing bracket is the original mounting solution, and the StageHand clamp was the upgrade path. Beyond that, the MD 504 is a simple, small, sturdy dynamic mic whose appeal is ergonomic as much as acoustic. It goes where bigger mics won't, and according to the contemporary review coverage it doesn't sound small once it's there.
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