Red Wire Impulse Responses | Speakerbox Series

In addition to the primary mic positions, for our Weber Blue, we used each microphone as a Mono Room mic at a distance of about 6 feet, midway between floor and ceiling and pointing it away from the speaker to catch primarily reflected sound in the case of cardioid mics.

A "Stereo Room" impulse is captured with a matched pair of Neumann KM84s or Earthworks TC30s in an XY configuration. We split the stereo signal into to two mono, left-right signals for convenience. We also use a KM84 or TC30 to sample the back of the cabinet at distance of about 12". We reverse the phase of this sample. It picks up mostly low end and room reflections and may be useful when blended with a another mic signal. For our Weber Blue we placed a BLUE Bottle with a B4 Omni capsule, placed about 5' and 10' (labeled Alt) off the back wall, as a neutral Mono Room mic.

Not every mic was sampled in every position and at every distance so check the IR Matrix for a comprehensive listing. We like to try different things, so each sample set has a few surprises.

Preview the Cabinet IRs!

Legal stuff: All product names used in this webpage are trademarks of their respective owners, which are in no way associated or affiliated with Red Wire Impulses. These trademarks of other manufacturers are used solely to identify the products of those manufacturers whose tones and sounds were sampled during impulse response capture.

The Microphones

Click on the mic name to see a brief description. Not every mic was used on every cabinet so check the IR Matrix of each cabinet for details.

AKG C414B-ULS

The C414B-ULS is a 4-pattern condenser mic with an input transformer. We used it in mainly in cardioid, but threw in an omni room IR or two for kicks. It has fairly flat response with a very slight dip in the upper-mids and a very noticeable proximity effect at close range (boosting the lows).
Audix i5

The i5 is a dynamic mic with a scooped mid range and a big presence bump. In our work, we found it to be a bright mic without much low end that works best at close range or out towards the cone on bright speakers like the Celestion Blue. It really seems to like the Jensen P12.
Beyerdynamic M160

The M160 is a oddity among ribbons due to its tight cardioid pattern. Work it close for a nice proximity boost. Pull it back and enjoy the mellow highs. It's hypercardioid pattern keep the room sound at bay even at a distance.
Neumann U47

A classic microphone used in countless legendary recordings. Extended lows, sweet mid-range and smooth high-end.
Neumann KM84

The KM84 has a flat frequency response which lends itself to use as a room mic. It's also nice when you want to capture the speaker as is, without adding a lot of coloration.
Neumann M8/CMV563

We put this one up, not expecting too much and were pleasantly surprised, so we kept it in the lineup. The M8 has a "vintage" rolloff of the highs frequencies which makes it nice for taming fizzy guitars and for use on bright speakers. It's also figure 8, so we had some fun with it and pointed its null point at the speaker to pick up mostly room reflections. We labeled these IRs, "NullAndWall". The reflections we captured with the Weber Blue might make an especially nice slapback reverb if blended with another signal. It's also interesting to note that this very mic was used by the East Germans to broadcast anti-capitalist propaganda into West Germany, or so we were told.
Neumann M7/CMV563

If it was good enough for the Beatles, then... well, ok... it's not a U47, but it's a similar capsule and on a CMV563 tube mic, it has some old school mojo of it's own.
Neumann U87

This one's a studio standard. We were especially careful not to overload this guy which can make it sound a little "honky", in our opinion. It seems to have less proximity effect than the C414 and picks up more high end. We did an omni room IR as well as a cardioid one.
Royer R121

Another ribbon mic. You can get real beefy tones taking advantage of the proximity effect and placing it up close, on the cap or cap edge. Smooth highs, and a nice balance at a distance. The figure 8 pattern lets in a little room which makes for a nice natural sound. We did the "NullAndWall" trick with this one, too.
Sennheiser MD421N

The 421 is a dynamic mic with solid lows and a flat response until a significant boost starting around 1.5K. It will make just about anything cut through the mix. It works very well off axis, too, if you want to roll off some of the presence and high end. We've got one of the vintage white ones with the tuchel connector and the funky, trailer park logo, which to our ears is more mellow sounding than the newer ones. It's wired differently than modern mics, so we reversed the phase on the pre when we recorded it.
Sennheiser MD441

The 441's low-end response is similar to the 421 but it has fuller mids and less edgy upper-mids.
Sennheiser MD409

The 409 rolls off the low-end before the 421 and has less edgy upper-mids and high-end. To us it sounds more like an SM57 with less peaky upper-mids.
Shure SM7

Kind of like an SM57 that's all growed up and has stopped borrowing mom's car to take the girlfriend to rock shows to impress her with wicked moshpit wrestling moves... Yeah... we don't know what that means either. Suffice to say, it's a lot like an SM57 with a less pronounced proximity effect up close (probably due to the recessed capsule) and extended, smoother highs. It has a similar vibe to the TAB57, so if the schedule was tight, we dropped the off axis positions on this one.
Shure SM57

A studio staple on electric guitar. Aggressive upper mids. Some proximity effect. Rolled off highs. Try pairing it with an R121 for a little of the chocolate and peanut butter thing.
TAB-Funkenwerk SM57

An SM57 with a replacement transformer made by TAB-Funkenwerk that extends the highs a bit and the lows a little bit more. Sounds like a crankier SM7 to us. You can judge for yourself.
Electrovoice RE20

Take it out of the kick drum and use it on guitar. It's a detailed, well-balanced mic with ample low-end. It's muted proximity effect can be useful.
Earthworks TC30/M50

The TC30 and M50 are high-end reference mics. They are flat as a pancake and have a phenomenal frequency response (3Hz-50KHz for the M50).
Lawson L47

Based on the Neumann U47, this one popped up in a few of the sessions. See what you think.
Blue Bottle/B4 (Room only)

High end tube mic with a nice neutral omni capsule that we thought would complement the other mics as room mics.
Blue Bottle/M7

We occasionally threw the M7 on this behemoth (in case you didn't know, the BLUE Bottle is a BIG mic) and put it up, mostly for kicks. You may find the results useful.

Mic Distances

We sampled each speaker and microphone combination at up to 8 distances: 0", 0.5", 1", 2", 4", 6", 12", and Room. For the Weber Blue, we were going for a roomier sound so we used 9: 0", 1", 2", 4", 6", 12", 24", 36", and Room.. As the mic gets further from the speaker, the captured sound tends to get progressively brighter as the low-end drops off. You get more ambient room sound the further away you place the mic. The 0" starting position is right on the grill, but not touching it, or parallel to the baffle in the case of cabs without grills or grill-cloth.