AKG H50 Stereo Bar for Two Microphones with Adjustable Spacing

AKG H50 Stereo Bar: Two Microphones From One Stand Base

The AKG H50 is a metal stereo bar that mounts two microphones on a single microphone stand, and AKG describes it as ideal for capturing stereo recordings. It fixes to a stand through a 5/8 in female centre thread and presents two 3/8 in male mounting points, one at each end, with the spacing between them adjustable from 2.36 to 6.69 in (60 to 170 mm). Item number 6000H05710 identifies it, and it appears inside several matched-pair microphone boxes elsewhere in the catalogue, which is how many engineers first encounter it. Its job is not to improve a microphone but to make a technique possible, since every coincident and near-coincident stereo array depends on holding two capsules in a fixed, repeatable geometry. Get that geometry right and a stereo image behaves; get it wrong and no amount of mixing repairs it.

Why Two Microphones Have to Share One Base

Coincident stereo recording works by capturing a source with two directional microphones whose capsules are as close together as physically possible, and a stand cannot do that with two separate booms. Placing the capsules close means the sound from any direction arrives at both of them at almost the same instant, so the difference between the two channels is purely one of level rather than of time, and level differences translate into a clean, mono-compatible stereo image; two microphones on separate stands inevitably sit inches or feet apart, which introduces arrival-time differences and the comb filtering that makes a stereo pair sound hollow when the channels are summed. A single bar also means one adjustment moves both microphones together, so an engineer who finds a good position over a drum kit can raise, lower or angle the whole array without disturbing the relationship between the two capsules. Repeatability follows from that, which is why studios that recall setups between sessions insist on a bar.

Spacing From 60 to 170 Millimetres

Adjustable spacing across a 2.36 to 6.69 in (60 to 170 mm) range is what lets one bar serve several different techniques. Bringing the two mounting points to their minimum separation is what a coincident XY or Blumlein array wants, since the goal there is to place the two capsules almost on top of one another with their axes crossed at an angle; opening the spacing out toward the maximum moves the array into near-coincident territory, where a deliberate small distance between the capsules adds a controlled amount of arrival-time difference and widens the perceived image. Mid-side recording sits at the closed end as well, with a cardioid facing the source and a figure-of-eight directly beneath or above it. An engineer working drum overheads, an acoustic guitar or a small ensemble can therefore audition a narrower and a wider image by loosening one adjustment rather than by rebuilding the rig.

Threads, Holders and Which Microphones It Carries

Mounting hardware is where a stereo bar either fits a studio's inventory or does not, and this one uses a 5/8 in female thread at the centre for the stand and two 3/8 in male threads for the microphones. Those two sizes are the conventional pairing in professional audio, with the larger centre thread taking a standard stand top and the smaller end threads accepting the swivel holders and elastic spider mounts that large-diaphragm and small-diaphragm microphones are normally supplied with, so a matched pair straight out of its box will usually mount without extra parts. Microphones commonly carried on it include the C214, C314, C391 B, C414 XLII and C414 XLS families, which is unsurprising since a matched pair of those is exactly the purchase that creates the need for a bar. AKG does not publish an overall bar length or a maximum supported microphone weight, so no figure is quoted here; the metal construction is what keeps a pair of heavy bodies stable at height.