Read on for an inside look at some of the, shall we say, non-optimal behaviors of the stock microphones, and an analysis of the mic after we replace 100% of the signal path.

Overview of the stock microphone

The CTM-100 is a rebranded Alctron T11A, the most popular version of which is the Apex 460. The tube is a 12AX7; both triodes are used in series. The transformer ratio is around 10.5:1.

The circuit is built with inexpensive parts, as you might expect from anything made in China to meet a low price point. IMO, the circuit contains some design mistakes, which negatively impact performance, although perhaps not as much as the inconsistent component quality, haphazard build quality, and most importantly, inconsistent capsule voicing.

Speaking of which, the capsule in all T11A mics is a 32mm K67. That’s a uniquely Chinese variation on the Neumann K67 design. The K67 capsule was designed to be used with high-frequency corrective EQ in the circuit. The T11A circuit does not provide any such filtering, so these mics often sound bright, especially when the low end is thin due to capsule manufacturing defects.

Acoustic analysis of the customer mic pair

We measured both stock microphones on our acoustic sweep rig. We use a gated impulse system to reduce the influence of reflections. We measure at 10 inches (mic to speaker), so these graphs show proximity effect for directional microphones.

The image at right contains two versions of the Cardioid frequency sweep. The top one shows that the two mics differ in sensitivity (measured at 1kHz) by 3dB. The bottom graph (click the thumbnail to see it) normalizes both traces to 0dB @ 1kHz, to make it easier to compare the frequency response after accounting for the delta in level.

Mic #1 has a HF peak at +4.6dB @ 11.7kHz. Mic #2 peaks at +2.2dB @ 12.8kHz. That’s a 2.4dB delta in high-frequency response, and the peaks are 1100 Hz apart.

10-12kHz is a frequency band where a little goes a long way. Peaks in that band that are greater than about +1dB need to be accompanied by a boost in the lows, or else the mic will sound bright. These mics don’t have a full bottom end, though; at our 10-inch measurement distance, we like to see a more pronounced lift below 100 Hz. The lack of low end energy contributes to the thin and bright sound.

Not a matched pair

Could these two mics, in their current form, be used for stereo recording? Sure. Any two microphones could be used to record in stereo. In the case of these two mics, you would need to adjust preamp gain to compensate for the 3dB delta in output level. You would need to EQ both tracks individually. And if the source contains much energy above 10kHz, both these mics risk pushing the converter into harsh distortion because the mic is exaggerating that frequency band.

Performance as a stereo pair would be compromised by the sonic differences between the microphones. Digital EQ can’t completely adjust the brighter mic to make it sound like the less-bright one. Therefore stereo imaging would be affected. Making great stereo recordings is much easier if the mics sound the same.

Circuit analysis of the customer mic pair

We tested the frequency response and distortion of the stock Carvin circuits by injecting a signal into the microphone. To be clear, this is not an acoustic test, but strictly an electronic test. This test bypasses the capsule, so that we can isolate the circuit (including tube and transformer) and graph its contribution to the sound of the mic.

The two Carvin circuits differed substantially in output level, by 4dB. That’s unusually high. With good-quality parts, this circuit should be within 1dB across multiple mics. This largeg delta suggests that one of these circuits has some incorrect or defective components.

The circuit frequency responses differed slightly, too. The higher-output mic had a 1.5dB lift from 5kHz to 18kHz. The lower-output mic had a 2.2dB lift in that region.

How much of a HF rise is appropriate for this mic circuit? I would say “none.” Some mic designers might want to boost the top end to compensate for a dark capsule, but that’s fairly unusual, and unlikely to explain what these graphs show. (And it’s worth recalling that the capsule used in these mics is arguably too bright already.)

Note the subtle oscillation in the response below 1kHz, too. That’s probably not audible, but indicates a problem in the circuit.

Now let’s look at distortion. In this graph, the heavy solid lines at the top show the circuit frequency response, which we’ve already seen. We’ve normalized both to 1kHz @ 0dB for this analysis.

The thinner solid lines show second harmonic distortion, which I’ll abbreviate as “2H.” This is one of the components of “tube mic sound.”

(Technically speaking, distortion is a defect, but let’s not pretend that the art of audio recording is about strictly and clinically capturing the sound in the room. Distortion is a musically useful effect. Ask any guitarist. It helps a source cut through the mix. It adds weight and mojo to a track. It’s not good or bad in itself, any more than the color blue is good or bad. What’s more important is when you use it, and how much, and what kind, and to what end.)

The dashed line is third harmonic distortion. Unlike 2H, 3H isn’t usually a desirable sonic seasoning. 2H is one octave above the source, and as such is always in key. 3H is three times the frequency of the source, which might or might not be in key, but is definitely not guaranteed to be, which means that instead of enhancing the source with saturation, it could potentially clash with the source by being off-key.

There is no rule about how much 2H is too much, but it is generally accepted that minimizing 3H is a good thing.

In the case of these Carvin mics, both 2H and 3H are higher than makes me comfortable; at moderate to high SPL, I would expect both of these mics to sound a bit rough.

Upgrade Options

Just to summarize what we’ve found: the capsules differ in frequency response. Both are thin on the bottom and hyped on top. The circuits differ in output level. Both exhibit an unwanted HF rise above 5kHz. Both have high distortion.

Replacing the capsules would re-voice both mics, but even if we installed matched capsules, the two microphones would not be matched because these circuits have a 4dB delta in output level.

Replacing both transformers might correct the output level difference, and might improve the distortion performance, but the only way to know is to do the replacement and then test both circuits via injection — which is to say, a lot of work, and a risk that the circuit problems were elsewhere.

Ditto for the tubes. Furthermore, even if the tubes or transformers were responsible for the mismatched levels and high distortion, this circuit — in my opinion — contains some other compromises that negatively affect performance. Component quality is poor. The is no room for an upgraded output capacitor. Some of the existing wire joints are burned.

We always planned to replace the entire circuit, because that’s what the customer requested. I included these comments about partial-upgrade options only to illustrate the tradeoffs.

When both the capsule and the circuit are compromised, the only way to fix the mic is to replace both.

The V-251 Circuit Upgrade

We installed the V-251 circuit into both mics. The V-251 is our version of the Telefunken ElaM 251 circuit design. Like the original 251, this circuit uses one triode of a 6072 tube, a fairly minimalistic audio circuit, and a T/14 output transformer.

The tube in this kit is selected for low noise and low microphonics. The circuit components are all very high-quality, e.g. precision audio resistors, our favorite electrolytic capacitor on the tube cathode, and a truly amazing copper foil output capacitor.

Because this circuit is most often used with the RK-12 capsule, which has a healthy bass response, the kit includes a high-pass filter feature. If the donor mic has external switches for pad and filter, the V-251 circuit accommodates those, but if the mic has no switches — as is the case here — the included internal HPF switch can be used. This allows the mic’s low frequency response to be attenuated when close-miking, to compensate for proximity.

We replaced all the internal wiring, too; the V-251 kit includes multistrand, Teflon insulated, silver plated copper wires.

Capsule Upgrade

The customer requested matched RK-12 capsules. This capsule is based on the AKG CK-12, an edge-terminated design that was used in the C12 and ElaM 251.

Results

The image at right shows signal-injection tests of the stock circuit vs the V-251 circuit. Low frequency 2H dropped by 13dB. 3H dropped by 10-15dB across the spectrum. Both of those are solid sonic improvements.

The two circuits differ by less than 0.2dB in output level. We did not take any steps to match the circuits. The parts in these kits offer consistent performance, so any two circuits are likely to be matched for both level and distortion.

The acoustic frequency sweep is even more compelling. In this graph, the red trace is the stock Carvin mic. Compare the bass response: the modified mic has a much fuller low end, which is appropriate for this 10-inch measurement distance. The high-frequency peak moved down from +4.6dB (!) to a much more sane +1.1dB.

The mic now sounds balanced and rich, with great bass extension and plenty of “air,” with no 10-12kHz harshness. The improved bass response allows positioning farther from the source without sounding thin. The internal HPF switch allows closer placements without bass overload.

Harmonic distortion is reduced, giving the mic more headroom. There is enough 2H to give the mic character, but not so much that it becomes an “effect mic.”

The modified mics will go head to head with just about anything else. Its performance is not held back by any of its components. It has no funky circuit topology errors. It’s a really nice example of an ElaM 251 style microphone, albeit with 9 polar patterns and a switchable HPF (features not found on the original).

Is it worth it?

Building a mic locker on a budget is challenging, because you need a lot of them, and they’re all expensive.

That’s why upgrading inexpensive microphones is one of the best ways to create a collection of nice mics. Most commercial products can’t come anywhere close to the price/performance ratio of DIY upgrades.

Not every cheap mic is worth upgrading, of course. But mics like this one, where the entire signal path gets replaced, have no ceiling, no throttle on potential performance.

The most useful comparison is to figure out what a comparable-quality commerial mic would cost, if you bought it new. The recipe for this mic is a single-stage (single triode) 6072 with fantastic components, a T/14 transformer, and a CK-12 style capsule… a combination sometimes described as the “Austrian” sound. Such a mic would cost you $1900-$2400, which is more than FOUR TIMES the DIY parts cost. Add in the cost of the donor mic ($200 used), and you’re still saving over $1200 to go the DIY route. (And just between you and me, the components in the V-251 kit are actually nicer than what I’ve seen in any commercial mics.)

And recording it, too, of course. [rimshot]

Last Fall, the server that had hosted this website for the past 10 years blew a disk drive. All the site data was stored on a mirrored RAID, so we didn’t lose anything other than sleep. Really the biggest problem was that the server hadn’t, up to that point, been rebooted in over eight years. I don’t say it’s a problem that we hadn’t rebooted the server, but rather the opposite — it’s damn impressive that the server had been running well, with literally no maintenance, for years. Seeing a server with uptime of less than six months always feels a bit like someone screwed up.

Some time around February, the server blew up another drive. And then I think one more in March? The incidents started to blur together into a sort of prolonged anxiety attack. It didn’t help that the NOC staff was using 10-year-old disk drives to replace the 10-year-old disk drives that kept dying.

Anyway, the ISP where that leased server had been racked for the past decade decided to get out of the business, so we had to move the site to a new facility. That has been a mixed blessing. The new hardware is about 5 times faster, and costs less per month. But our entire application stack was 10 years out of date. Current revisions of the host environment have deprecated several core libraries, which basically means the site did not work AT ALL after we migrated it — just white screens of death at every URL. We’ve been updating code for weeks.

We’ve fixed most of the problems. If you see something that doesn’t work, leave a comment to let me know.

Well. The point of this was not supposed to be a depressing tour of old technology whose time had finally come, but rather to give the backstory on this glorious (?) rebirth of the website. I think all those smoked disk drives were maybe just a cry for help. The mic database just wanted some attention.

So, we’re running on current versions of OS and application environment and database, and we’ve fixed a bunch of bugs in the code, and we’ve added a handful of mics to the database. Many more updates are in the works.

The S350DBs are a tri-amped (150W total) satellite-and-sub mini-system with titanium tweeters, 3-inch mids, and an 8-inch subwoofer. They feature digital connectivity including Bluetooth. Their tag-line reads “Old school style, modern sound,” and that hits pretty close to the mark. With their dark wood-grain cabinets and metallic silver dustcaps, these speakers have a decidedly Modernist feel. They would look right at home next to an Eames chair in a converted loft space. Even the quality of their build seems like it is from another era. They are weighty and have a visual gravitas. And they do all this for $299.99.

Reading Edifier’s promotional material, the phrase “modern sound” worried me as I waited for the test speakers to arrive. I worried especially because Edifier does not try to hide the fact that these speakers use DSP to control frequency response and dynamics. When I think of “modern sound” tailored by EQ or DSP, I think about the rubbery compressed bass of the first-gen iPod shuffle, or the beguiling but ultimately frustrating sound of so many Bose products. But once they arrived, it was clear that the S350DBs avoid the usual pitfalls of “euphonic” audio.

Like other EQ’d or DSP-controlled audio products, the S350DBs sound engaging and satisfying right out of the box — but unlike others, their sonic character doesn’t begin to wear quickly. There is no sense (as there is with Bose in particular) of being able to hear the EQ working. There was no point at which I could hear the amplifier sweating (as it were) to push the woofer below its resonant frequency. And, with the efficiency and extended range of the S350DB’s 3/4-inch tweeters, there was no excessive high-frequency noise like I expect from a system trying to reach 20kHz through treble-boost. A/B testing versus my Bose Lifestyle powered speakers really made this clear. I also pitted them against my Alesis M1Active monitors (also powered speakers with a 3-inch driver, 3/4-inch tweeter, and onboard DAC). They sounded remarkably similar. In fact, while the Alesis speakers sound slightly colored around the port frequency, the Edifiers do not -– although masking from the sub may have something to do with that. If I could pair the M1Actives with the S350DB’s sub, I think they would be hard to tell apart.

So, what about the claim that they sound “modern?” I would argue that they sound quite a bit better than what I think of as “modern.” In fact, they sound like an old friend. If you are old enough to remember the Realistic/Optimus micro-monitors in cast metal boxes , these speakers will sound very familiar –- except that unlike the limited-bandwidth Realistics, the S350DBs produce all the frequencies you can hear, and some you probably can’t.

Another modern pitfall the S350DBs avoid is drivers selected for trendy form factor rather than their ability to reproduce sound accurately. Honestly, if you want wacky flat-panel micro-speakers, Edifier makes those too (although even those sound far better than I would have expected). The S350DBs do it right. The 3-inch mid-driver is small enough that it does not “beam” at the frequencies it is required to reproduce, so dispersion is wide and uniform. The 3/4-inch titanium tweeter is also narrow enough that it avoids off-axis cancellations –- so unlike the ubiquitous 1-inch dome, it has a chance to actually go up to 20kHz instead of rolling off at 17k. The 8-inch subwoofer is large enough to reproduce sub-bass with minimal help from the DSP, and yet small enough to sound fast and coherent. My only quibble with the woofer is that as long as Edifier is correcting frequency response with DSP, I would have preferred a sealed sub. Both the sub and the satellites are ported, and have a very slight but audible port chuffing at high volume -– certainly no more so than any other ported system in the world (and less than many, due to their single-flared port tubes). I had hoped to see a reassuring puff of polyfill in the ports… I didn’t, but that doesn’t necessarily mean it isn’t there. I had also hoped as I waited for the speakers to arrive that the conical domes on the drivers would be real aluminum phase plugs. They aren’t, but at this price point that is par for the course. That is the only tick in the “fake retro” box, and sonically the system doesn’t suffer for it. In fact, there is a very pleasant clarity and coherence in the S350DB system. I would not be surprised if there were some amount of DSP time-alignment going on, because neither the aforementioned coherence nor the apparent frequency response seems to change if the listener moves up and down on the vertical axis. I also tried laying the satellites on their sides, but this obscures the volume, bass and treble knobs on the side of the right satellite . Incidentally, the knobs feel smooth and high quality, and the bass and treble controls sound like they add maybe +/-6dB of EQ — a classy touch that shows that these speakers are not made for frat-boys and philistines.

That brings me to my next point of contention with Edifier’s copy writers. The S350DBs are described as having an “8 Inch Booming Subwoofer.” To my great relief, there was no “booming” to be heard. The sub may not be as hermetically pure as a sealed unit, but this is where the DSP really shines. Unlike most ported subs, the S350DB’s never loses its composure. The excessive cone excursion and loss of control which I expect to hear from a single, ported 8-inch woofer trying to reproduce two channels worth of sub-bass was almost non-existent. The fact that this was achieved with DSP compression made me feel a little uneasy, but not as uneasy as I feel while listening to a woofer trying to shoot its voice coil across the room.

As an amateur recording engineer, I do not like the idea of any kind of signal modification between me and the original recording, but listening to the Edifiers made me realize that material-engineering issues like speakers with uncontrolled excursion, poor dispersion, poor time alignment, and phase shift from speaker-level crossovers all add up to a pretty heinous level of signal modification in their own right. DSP compression, time correction and EQ may technically be distortions, but they are less audible than the old mechanical distortions. These days, dynamic processing with DSP is incorporated into many very expensive powered studio monitors.

Edifier notes that the DSP provides both compression and expansion. Dynamic range expansion could be a really unpleasant feature, but in practice I could not hear a bit of it. If used judiciously (the way Neumann’s monitors do it, for instance), it can reduce intermodulation distortion. I don’t know if the Edifiers are that advanced, but given how much I like them, I’m going to tell myself that they are.

Modern electronics also mean modern compatibility. The S350DBs have optical and coaxial digital inputs, standard RCA inputs, and Bluetooth. Input switching and volume can be controlled with the included remote. The lack of USB input is disappointing, but their Bluetooth connectivity and fidelity make up for it. Being able to play music from my phone with very good sound quality and no setup or extra gear was a treat.

As someone who regularly modifies speakers, swaps components and tries all the snake oil, I was pretty surprised that these speakers made me happy. They just don’t do anything wrong. You pull them out of the box, pair them with Bluetooth on your device of choice, and you have great audio. Are they perfect? Maybe not, but they are made so well that spending extra money for upgrades or modifying them would bring you immediately to the point of diminishing returns, and in my book that means that the S350DBs are very, very good at what they do.

I have good relative pitch. I can tell when one of my strings, or one of my bandmates, is out of tune by a few cents. Having my guitars precisely in tune is important to me. More than important; it’s mandatory. And you can’t just tune my guitars any old way — there is a certain method. Strings must be tuned up to pitch, then stretched (bent) a whole step, then rechecked for pitch. That way, the guitar will stay in tune for a whole set, regardless of how hard I attack the strings. So I was dubious that Roadie 2 could live up to my standards.

Roadie 2 is a computerized, motorized, stringed instrument tuner, roughly the size of a deck of cards. It sports an attractive OLED display that serves as menu and directs you during the tuning process. A multifunction knob serves as controller. A LiPo battery is rechargeable via the supplied USB cable, and is reported to last “for a month of regular tune ups, retunes and restrings,” though I have not had it long enough to exhaust the battery.

The basic procedure is simple. Press the knob’s center button to turn on, twist the knob to choose an instrument (Acoustic, Electric, etc.) and the name of the first string appears (E2). Press the button again, and you can choose an alternate tuning from a preset list. (You can add custom tunings using the app; see more on that below.) With the name of the first string showing, hold the device over the tuning peg of the appropriate string and puck the string. Roadie 2 listens, then turns the tuner for you, quicker or slower, depending on its whim, with a winning, droid-like whine. Some patience is required as Roadie 2 trains you to pluck the string more than once, while it listens to the pitch. When Roadie 2 senses the string is tuned, it beeps, vibrates and flashes (providing valuable feedback for noisy environments), and highlights the name of the next string (e.g., A2).

[The Roadie 2 demo video below is from Engadget. –Ed.]

When Roadie has tuned all six strings to its satisfaction, you will find… a poorly-tuned guitar.

For purposes of tuning, a semi-tone (a step of one fret on a guitar) is divided into 100 cents. Any digital tuner will allow you to tune to within one or two cents. While Roadie 2 does OK with the thinner strings, it consistently tunes my low E flat by five to ten cents, and takes a long time doing it, as if it was having a hard time hearing the string.

I tried Roadie 2 on six different fixed-bridge electrics and one acoustic, and it struggled with the low E and A strings on all of my guitars. I tried varying my technique, plucking the string louder or softer, with rounder tone (thumb) or sharper tone (fingernail), all while keeping the other stings muted. Nothing helped. On the other hand, Roadie 2 was more reliable on the four higher-pitched strings, generally leaving them within a couple cents of true.

I learned that the Roadie 2 has a “Tune Up” feature, available in Settings, that causes Roadie 2 to loosen strings first, then tune up to pitch, addressing my earlier concern. This is a nice feature, and is not mentioned in the user guide. However, it did not solve the issue with poorly tuned low E and A strings.

Regarding my experience with poor tuning, Band Industries writes, “Roadie is designed to tune for attack and not for sustain. Meaning while plucking a certain string the frequency of the string varies from high to low (high at attack and low at sustain). If the pluck is strong the frequency can vary up to 0.5 Hz or even 1 Hz. …[because] we tune for attack, there is high chance when observing the signal on a rack or other tuning indicators the player will observe the string as tuned flat.”

Low E = 82.41 Hz. If I pluck hard and the attack is 1Hz sharp, that’s still only 1.2 cents, and it doesn’t explain the poor performance I’m seeing. Band Industries promises new firmware to address this issue, and I will amend this review at that time.

What about alternate tunings? I rarely play alternate tunings because, unless you practice this a lot, like Ani DiFranco, it’s challenging to change tunings between songs, and I don’t have a guitar tech, nor enough guitars to leave one in an alternate tuning. Maybe Roadie 2 can help.

The free Roadie app (I installed the iOS version; I assume Android is also available, but it doesn’t say on the web site) is required to create and manage alternate tunings. After some minor bother setting up the app (they require you to register and log in) I was able to create a custom tuning, Eb modal (Eb Bb Eb Eb Bb Eb), a tuning I use for Suite: Judy Blue Eyes (Crosby Stills & Nash) on acoustic guitar.

After syncing with Roadie 2, the custom tuning is available in the menus. In use, the poor accuracy for low strings is the same, but I was encouraged that Roadie 2 can get my guitar in the ballpark faster than I could by ear. And putting my guitar back into standard tuning was just as quick — about twice as fast as I can manage on my own.

Band Industries promises increased accuracy as they refine their software and issue firmware updates. So, I’ll hold out hope that they can improve performance on the low E and A strings. Until then, I’m still not letting a roadie tune my guitars.

Click for more info on the Band Industries Roadie 2 guitar tuner, USD $129.00.

[Editor’s note: Thanks to Band Industries for providing a Roadie 2 in exchange for an honest review.]

The folks at H.O.M.E. — that’s “Helping Our Music Evolve” — miss that, and they think you do too.

“Helping Our Music Evolve” is a non-profit 501(c)(6) membership organization that acts as a launchpad and home base for music creators looking to get their foot in the door of the music business. That includes songwriters, musicians, and producers, as well as those that form the teams around them, such as managers and agents.

The organization’s headquarters is a studio, performance space, and musician hangout, all located inside the Center 615 building in East Nashville. And because this is the 21st century, it has an online component, which has a directory of all its members and a robust search feature to help you find somebody to make music with (the brochure says it’s been called “the LinkedIn for the music industry”). My favorite part, however, might be the coupon section for discounts at local restaurants. H.O.M.E. gets it: musicians are broke.

In the fall of 2017, I went out to visit H.O.M.E. and interview the founder, Logan Crowell.

AF: So tell me the story of H.O.M.E.. What was the genesis of the idea?

LC: I came out to Nashville to start a band. I wanted to get some really badass players on my team and pay my dues. And I would ask around, ‘where do I go to plug in? Where do I go to build a band?” And all I got were answers like, “well, there are these jam nights” and, “you can go to these music industry mixers and meet people’ and stuff like that. And I thought, “there’s not a physical location in this town that everybody uses as a central hub? That seems like it should be a thing”.

AF: A lot of people don’t do what you did: come to town and ask, “Is there a physical place?”. That’s a unique way of thinking in this digital age, when a lot of folks would say, “Well, we have Facebook…”

LC: Yeah, that’s what people kept telling me, “there are these Facebook groups…” And that’s cool but if I’m going to build a band with somebody, I want it to be a long term thing where we hang out and enjoy making music together. It’s not just me hiring you for a set or whatever. In Nashville, where everybody’s coming here for music, it seemed like there would be a place like this. I just thought there would be some sort of central musician hang spot, whatever that looked like.

It hit me that this was a big idea. I had to take a few days to think about what it might mean, and pretty soon after, I hired a consultant to talk me through the process of forming a non-profit company and what things would be allowed. I read about 40 pages of tax law and I ended up going with a 501c(6). I started having an idea of how much this business — the nonprofit and the membership model — could knock down the cost of content creation and space.

It’s like a gym: if you’re trying to work out, and you try to buy all the gym equipment yourself, it’s crazy expensive. It’s nice having your own space, but for those who are at the entry point or for those who have some momentum but need a space to consistently create content, a shared space is a great thing.

AF: So the physical space exists to lower the barrier of entry for new bands, musicians…

LC: Yeah. The sharing economy. Exactly. And it’s not about making more money because my target market is people who are already broke!

AF: When did you get the address?

LC: It’s a funny story. So we’re at 615 Main Street, and I met Christian [Paro], the owner of this building the first time I set foot in here. I was just looking to rent a cubicle. But I told him that my home address was also 615 on another street, and we just hit it off. I got a cubicle in here and a couple months later, we decided we were going to open this space. We made the official announcement at 615 day, a festival over on Fatherland Street in East Nashville.

AF: So it’s mystical and numerological! 615 is Nashville’s area code, and 615 Main Street and…

LC: Absolutely. There’s some voodoo going on! Christian had always wanted to build out the space in the back of Center 615, and he enjoys being in the mix of what’s going on in town, so it was a mutually beneficial thing.

The space in question is 7,000 square feet inside Center 615, and it’s nearing completion as of this writing. The space will open on February 15.

Inside, there is a control room with seating for students, a live room that doubles as a rehearsal space, a separate production suite, a spacious lounge and reception area, and a big performance space. Outside, find a large courtyard for hangouts, games, and more live performances.

Every room at H.O.M.E. is connected with Waves’ SoundGrid system, which allows audio to be routed anywhere via cat5 ethernet cables. So an engineer can be working with Pro Tools in one of the two control rooms, while that audio is streamed to the other control room, where a different engineer is using Logic. Or the audio from the performance space can be streamed to Facebook Live while also being recorded to Nuendo on a laptop in the lounge. All this is because Crowell and Falcone understand that artists don’t need to own this equipment so much as they need access to it in order to create their music.

And once that music is created, H.O.M.E. want artists to show it off by playing live at the performance space, just next door to the big Studio A control room.

“We think this space is going to be like no other in town,” says Falcone. “we’re going to have projection mapping, a bunch of moving head lights… we’re bringing festival-style production to a venue in Nashville.”

“It’s not about draw — you know: filling up the room if you want to play here,” says Crowell. “I always use the term ‘proving ground.’ It’s about having a place where you can go in and see where the bar is set and you can see if you’re ready to beat that. It’s not a competitive thing, it’s just that it’s hard to know where you are until you get next to some one who is head and shoulders better than you.”

Every square inch of H.O.M.E. will be accessible to members for a monthly fee. There are three tiers to their membership, starting with the Music Community level, which gives access to the member directory and “LinkedIn” features of the website. Production Accelerator and Artist Accelerator packages give access to the studio, performance space, and more.

H.O.M.E. exists to help artists make their art and build their careers. It has the expensive equipment artists need but can’t afford to own, it has the performance space for artists to show their stuff, and above all, it has a physical space to encourage real connection and community, which is the only way to build a real team that’s stable and stands the test of time. “It takes the internet out of the equation,” says Falcone.

Taking the internet out of the equation: that’s a bold statement in our technological times. But real face-to-face relationships still matter, and musical magic is still made when human beings are in the same room with one another. Logan Crowell and Anthony Falcone understand this and that’s why H.O.M.E. has an analog heart in a digital world.

The HD cart is a reverb plugin from Reverb Foundry modeled after a very popular reverb unit from the mid 80’s: the Lexicon 480L “Digital Effects System,” with the HD Reverb/Surround expansion cartridge.

User Interface

The first thing I noticed was the plugin’s large GUI. I find I prefer a bigger GUI on plugins; they are easier on the eyes. Looking at the metering, you can see the input and output of the signal, and separate metering for the reverb and early reflections — the latter something I have never seen on a reverb plugin.

Where some reverb plugins can get intimidating really quickly, I find HD Cart very easy to use. Instead of throwing all its features at you, it handily tucks away its additional features under 5 categories: Master, Character, Low Control, Advanced, and Reflections. Though this plugin offers plenty of control for advanced users, you can get great results by only using the options under the Master section. This makes HD Cart great for novices as well as seasoned engineers.

The Master section offers individual controls for the reverb and early reflections, as well as the rolloff for each. Both rolloffs range from 20 Hz up to 22 kHz.

Under the Character section, you have options to control the pre-delay, diffusion, spread, size, and spin rate. Spread adjust the perceived size of the room. Size adjusts the volume (in terms of dimensions) of the room. The spin rate controls the speed of a form of modulation that is similar to traditional chorusing, but doesn’t introduce the phase effect associated with chorusing.

The Low Control section offers fine-tuning of low end response of the reverb: bass decay rate and rolloff frequency, bass boost level and frequency, and pre-delay time.

Things really get interesting with the Advanced section. Here we have control over the Treble Decay, with individual controls for decay rate and rolloff frequency. The unique “Recirculation” control, set to Enhanced mode by default, determines how the plugin’s two reverbs are combined; this mode produces a “more spacious” reverb than the original Lexicon algorithm. Disabling Enhanced mode creates a more authentic Lexicon/HD sound.

The Front and Rear control determines the balance of the output levels between the master (front reverb) outputs and the rear/surround outputs. To be clear, this control does not move the sound from front to back, but it does affect the relative volume of the rear reflections (which are further controlled by the tools in the Reflections panel).

The Wander control provides a type of modulation that can be used to make the space sound more lively. The Reflections panel allows you to alter the early reflections for the front and rear outputs. Putting all these features together and you have all the options you would expect of a reverb plugin and much more.

Audio Testing

Let’s get into how this sounds. It didn’t take long for me to realize that the HD cart was something special. I first tried it on a vocal I tracked from an artist named A. Rose. Using just the controls in the Master section, I quickly had a vocal that felt more emotional in a way that I’ve only experienced with a select few reverbs. Using the other controls I was able to dial in a flattering reverb space around the vocal. The low boost under the Low Control section helped add a little mass to the reverb tone.

Next I tried HD Cart on a piano from Juliana Parker. Again, HD Cart produced a gratifying sense of space around the piano. The ability to roll off the low and high end came in handy; I was able to shape the reverb to my desired specifications. EQ controls, even if just low and high pass filters, ought to be available in every reverb.

Generally my mixes almost always feature reverb on vocals, piano, and strings, depending on genre. I tend to use different reverbs on each. I use simple reverbs that I can dial in quickly, and reverbs that allow deeper experimentation. I found that HD Cart was able to handle all of my reverb needs. From dialing something in quickly, to really moving knobs around, HD Cart delivered rich sentimental reverb tones.

Overall, this plugin excels at producing lush reverb tones that I had previously only heard with analog reverb units. Many plugins claim to accurately reproduce the same sound of their hardware counterparts. While I can’t compare this to the hardware, I will say I feel it does sound like a hardware reverb unit. For such a complex reverb plugin, I was shocked and how little CPU it used. I tested the VST3 version of HD Cart, on an iMac running MacOS 10 (Sierra).

HD Cart has quickly became my favorite reverb plugin. Using it will have your colleagues asking “what reverb did you use on this?”

When compared to other reverb plugins I use regularly, HD Cart outperformed each of them, each time demonstrating its wider, deeper, more lavish reverb tone. Aside from its impeccable sound, I have to give a virtual “high five” to Reverb Foundry for the impressive GUI. I absolutely love it. Everything is easy to read, and I like how the additional features are categorized.

I highly recommend reading the manual to learn more about the hardware unit and to fully understand all the features available to you with this plugin.

Demonstration and Audio Samples

The HD Cart plugin will cost you $199. A 14-day demo is available. An Ilok 2 or 3 is required. For more information, see ReverbFoundry.com.

Save $150 on HD Cart

Through February 15, you can purchase the HD Cart reverb plug-in at a significant discount in a bundle deal with Roswell Pro Audio microphones. For example, purchase a Roswell Mini K47 for $299, and get HD Cart for $50 — that’s a 75% discount, a savings of $150! See details here.

Recording Studio Rockstars – interview with matt mcglynn

The idea, in a nutshell, is that engineers can intelligently build up a mic collection by paying attention to a couple key characteristics of the various choices they’re considering. Nobody wants to buy three mics that all sound substantially the same, right? With a couple minutes’ education (which unfortunately I spent an hour trying to deliver — please bear with this first draft attempt!), any audio engineer or studio owner can quickly classify microphones into a handful of sonic categories. If all the mics you own sit in one or two categories, you’ll need to pick something different next time out. This presentation helps you do that.

Please give it a listen. And don’t miss the downloadable PDF guide to building a mic collection; they turned out much nicer than I expected when I promised Lij I’d put something together. 🙂

Photo credit: I believe my pal Ken Levy took this one, at Summer NAMM 2017. That’s Lij on the left, Chris Selim of Mixdown Online in the middle, and me on the right.

(What I didn’t envision is that it would take 10 years to build! In fact, I naively thought I’d knock out the entire history of microphones first, and then move on to preamps, compressors, and so on. I haven’t given up on the preamp idea… do me a favor and check back in about 10 more years, ok?)

While the microphone piece of this project is still in progress, I already consider it a success. I’ve heard from hundreds of musicians and engineers over the years who have used the numerous mic shootouts or the Mic Database to make gear choices. I was blown away when Warren Huart mentioned in our recent “Mic Madness” Youtube Live event that he personally found the RecordingHacks site inspirational in building his own business. It is incredibly touching to learn that this project that I built for my own use has become a critical reference tool for so many people. To those of you who have reached out over the years to express that this site has helped you: thank you!

Many long-time readers already know that my mic obsession took an unexpected (to me) turn a couple years ago, when I founded a … wait for it … microphone company of my own. It’s called Roswell Pro Audio. The company doesn’t make any “me too” models or “clones,” but rather borrows proven capsule and circuit designs and combines them in new ways, filling sonic niches that are otherwise under-served by existing commercial options.

The idea was not without significant risk. Did the world need another microphone company? I am grateful that the answer was yes; my efforts have been blessed by uniformly great feedback from a ton of people I respect. The Roswell microphones have been widely praised by producer/engineers including Greg Wells, Ross Hogarth, Mike Poole, Andres Saavedra, by magazines including Tape Op, Recording, Sound On Sound, Pro Sound News, and by musicians including Phil Collen of Def Leppard, Casey McPherson of Flying Colors (the Portnoy/Morse/Morse supergroup, one of my favorite bands), and by Luis Fonsi. More importantly, the Roswell mics have generated incredibly positive feedback from many hundreds of home studio owners, who are finally able to get the sounds they hear in their heads into their mixes.

But not everyone who needs a Roswell mic has heard one! That’s why we’re giving one away. Better still, we’ve reached out to some friends in the industry to put together a prize package worth over $600:

• Transgressor transient editor/EQ for drum processing, from Boz Digital Labs ($149)
• Cloud Microphones’ Cloudlifter CL-1 mic activator / inline preamp for ribbons and dynamics, $149
• Roswell Mini K47 Microphone, $299

You can hear the Mini K47 in the demo video below. The mic was used on drum overheads, guitar cab, and bass. (The Roswell Delphos was used on kick drum and vocals.)

To enter the giveaway, sign up below the video! Update: the original drawing was held in November, 2017, but Roswell Pro Audio currently (as of May 2020) gives away one mic a month. See details here.

If you’ve done DIY audio for any amount of time, you’ll have collected a bin of leftover parts. Mine includes a bunch of unlabeled microphone output transformers that were pulled from a variety of cheap microphones. Chances are I’d never want to actually use one of them, but sometimes in the thick of R&D there’s a need for some oddball ratio that maybe I have on hand, if only I knew what the #$%&@! was hiding in that parts bin.

So, tonight’s project is to measure all those unknown transformers. Here’s what you’ll need:

• Signal generator
• Audio interface
• Multimeter
• Jumper cables
• 1/4-inch TS cable to sacrifice

The basic plan is to output a 1kHz audio signal from your computer, into the transformer primaries. Then measure the AC voltage coming out the secondaries. Divide the input voltage by the output voltage. That’s it. Read on for the details.

Signal generator options

There’s no need to buy a hardware signal generator. You can send a 1kHz tone from your DAW, if you have a tone generator plug-in. Or play this Youtube file. Or play this WAV file. Or use this tone generator app (MacOS/Windows).

I use the pictured ToneGenerator app; the screenshot at right shows the actual configuration for a 1kHz tone.

You’ll need to configure the software to send its audio output to your audio interface. In ToneGenerator’s preferences pane, you can set the “sound play device” using a pulldown menu. Select your audio interface from that menu. If you have no external audio interface available, you could use the computer’s built-in headphone jack.

Get the signal out of the computer

My USB audio interface is a Mackie Onyx Blackjack — solid, reliable, and cheap (e.g. $69 at Amazon). It has two quarter-inch TS “monitor out” connectors on the back. These provide an easy way to get audio out of the host computer.

In lieu of that, you can certainly use the headphone jack on the computer.

For my interface, I needed a 1/4-inch TS cable. I found an old TS-to-RCA adapter cable in the spaghetti mess of my abandoned cable collection. I cut off the RCA end, twisted the braided shield wires together, and tinned that and the center conductor so they wouldn’t fray.

If you don’t have a TS cable available to cut up, you could probably use an intact one, and clip jumper wires to the tip and sleeve of the free end.

Once the male TS end was plugged into the Blackjack’s monitor out, and the ToneGenerator app was configured to send audio to the interface, I had my test tone available on the two bare wire ends of my adaptor cable.

Set output level

Set your multimeter to AC. (Audio is an AC signal.) Clip the meter’s leads to the two conductors of the audio output cable coming from the audio interface (or headphone jack). Then turn up the monitor or headphone output of the audio interface until the meter reads 1VAC.

It is not necessary to set your output level to 1V, but the examples below assume that you have. Whatever value you set here, write it down, and use it in the calculations to follow.

Get the audio into the transformer

I used two short jumper cables to connect these to the transformer primaries. But you could solder your audio cable directly to the transformer wires if you don’t have jumpers handy.

How do you know which two wires on the transformer are the primaries (aka inputs)? I’d start with the pair that is red/white or red/black. But there are no standard wire colors. Worst case, you get this backwards and later measure HIGHER voltage on the output — that’s a sure sign that the transformer is a step-up design, or you’ve wired it backwards.

Read the output voltage from the transformer

This step is easy: just clip the multimeter’s leads to the output wires on the transformer. Assuming this is a typical audio transformer and you’ve successfully identified the primaries, you’ll read a value between 1/5 and 1/2 of your input voltage. Write down the value.

Then divide the input voltage by the output voltage. That simple calculation reveals the transformer’s turns ratio.

Examples

For the first example, I did a sanity check: I measured a transformer I know to have a 6.5:1 turns ratio. It’s a transformer we have custom-made for several of the DIY microphone circuit kits we developed for MicParts.com.

In this case, the input voltage was 1.0V (or, for the purposes of the math to follow, 1000 millivolts). The multimeter showed me 155.1mVAC at the output wires of the transformer.

To find the ratio, divide the input voltage (1000 mVAC) by the output voltage (155.1 mVAC). The result is 6.45. So, this 6.5:1 transformer has an actual ratio of 6.45:1. That’s typical; read on.


I repeated the test with a Cinemag CM-2422, a very nice 6.5:1 transformer, and got essentially an identical result (154.8mVAC output). 1000/154.8mVAC = 6.46:1.

Finally, I measured an unfamiliar transformer. It was taken from an M-Audio Luna, or Sterling ST55, or Groove Tubes GT55 — I’d lost track of which was which, but they all look identical. The input was still 1000mVAC. The output came up as 217.2mVAC, giving a ratio of 1000/217 = 4.6:1.

Next steps

Now that you’ve measured all those leftover mystery transformers, label them! Or else I promise you’ll end up measuring them again some late night three years from now. 😉

It was good fun, and we got into some detail about a number of things (but of course mostly about microphones!).

Here’s the recording:

Because several people have already asked: I used my go-to podcasting mic, the beyerdynamic M 99. That was my personal favorite from the Ultimate Podcasting Mic Shootout.

My studio isn’t really set up for video, so rather than drag my usual preamp, interface, and and outboard gear across the room I went super-simple on the audio chain: mic, Mackie USB interface, laptop.

By the way, this video contains the first public announcement of the new and upgraded Roswell Mini K47 condenser microphone, which is now available through discriminating dealers around the country (and soon, world). More info here.

Warren talked about doing another Mic Madness session. If you’d like us to, leave a request (or even a specific question) here or on the Youtube video.