Homebrewed Music

As I’ve mentioned before, for many years I believed the recording advice I found on the internet. I visited recording forums and searched for discussions of acoustic guitar recording, and bought gear based on those discussions. I was never happy with my tracks, and I hoped that I could find the combination of gear that would make my recordings sound great.

One consistent recommendation was the Schoeps line of microphones. I was lucky enough to find a deal on a pair of used Schoeps CMC64s (CMC6 modular bodies and MK4 cardioid capsules) a few years ago, and even though they were fairly expensive I bought them because I knew that once I had a pair of Schoeps, I could no longer blame the microphones for my less than satisfactory results. (more…)

Mics are fun. They are a great gear fetish item, because they’re collectible, a bit esoteric but still familiar, come in a wide range of types and sizes, and most of them have a bit of a phallic quality (grin). Even better, when I read about microphones on the internet or in recording magazines it seems that each mic has a dramatically distinct personality, and a big part of the job of a recordist is choosing the optimal mic for any given source and style.

Sometimes when I’ve listened to mic samples I thought I heard these dramatic differences, but after a bit I realized that I was listening to different performances, not different mics. Sure the mics had been changed, but the player was hitting the strings differently and playing different riffs at a different volume – so how could I tell what part of the difference was the mic, and what part the player?

Since then I’ve tried to do some mic tests of my own, and I’ve tried to educate myself on audio testing. At this point I’m beginning to think that the differences in microphones are a lot more subtle than I had been led to believe, which makes a careful test even more important. As I’ve mentioned before, very small differences in volume are registered by our ear/brain combination as differences in quality rather than loudness. I’d like to demonstrate the steps I now take to try to make my mic comparisons, and preamp and a/d comparisons, meaningful. (more…)

This post will reveal the identity of the comparison clips in the post comparing the M-Audio Profire and the Lynx and John Hardy recording chain. But before providing the answers, I’d like to pose a question.

I (naively) expected that people would embrace an opportunity to do some controlled testing, using an easy but very effective comparison technique. I have found that careful ABX testing, using Foobar2000 and the ABX utility included in the program, has made me a better, more careful listener. I learned that the perceived differences between clips became much less when I no longer knew the source of the clip. As a result, I learned to search out subtle differences in tone color and texture. I also learned that I can’t hear any difference between systems that I have been told should show night and day differences.

I’d hoped that a number of other folks would try careful ABX testing of these clips with a statistically significant number of trials, so I could compare my results to theirs. At this point, I don’t know if my inability to hear the differences is normal or unusual.

The Question

If you visited here, listened to the clips, maybe even downloaded and installed Foobar2000, why did you not go the next step and run a test of 20 comparisons? Foobar2000 makes it easy to save your results and share them with the world, or not. Wouldn’t you like to have a personal evaluation of the difference between a high end preamp and a commodity unit, or between 44.1 and 192 sampling rates? Wouldn’t you like to contribute to the knowledge of the recording community?

After all, if the huge differences we read about in magazines and online are true, it will be easy to pick out the different samples, and we can get busy saving up for high end equipment. But if those differences are actually imaginary, driven by normal human traits like confirmation bias, we can save a bunch of money and time and trouble by ignoring gear lust and concentrating on mic placement and room acoustics.

So the question is, what do you have to lose by conducting a thorough series of ABX comparisons and reporting the results?

The Answers

(more…)

This is probably about as close to a political post as I am likely to write. I think that listening “tests” that are not conducted as double blind side-by-side comparisons are just wishful thinking. We wish that human hearing were not so totally dominated by the vagaries of our brain/mind, but it is. We wish that we could retain accurate mental images for more than a few seconds, but we can’t. We think we can discount the impact of small volume differences, but we can’t, and the smaller the difference the more likely we are to describe it as anything but a volume difference. We think we can trust our ears but all the evidence gathered from controlled experiments tells us plainly that we should not.

Since my interest in recording began only a few years ago, I’ve always had the internet as a resource for learning about the subject, I researched in every forum and magazine site I could find. And I now firmly believe that most of what I learned there was incorrect. (more…)

For sheer acoustic guitar and recording fun, it’s hard to beat a visit to Doug Young‘s garage studio. Doug is a fantastic player, very knowledgeable recordist, and has some swell guitars sitting around his great sounding studio space. As an aside, he has done all us acoustic guitar players a huge favor by compiling a great set of pickup samples on his web site. His CD is definitely worth adding to your collection, and his articles in Acoustic Guitar Magazine are always good reading as well.

But for this occasion, I went to take advantage of his extremely cool Sound Devices 744 digital recorder. This is a top of the line system, used widely for major motion pictures or any other situation where great sonics, ruggedness, and portability are needed. I came for a shootout between his “king of the hill” unit and my much more modest recorders, a Fostex FR2-LE and a Zoom H2. Once I arrived, Doug suggested that we add his Edirol R09 to the mix, so we had four field recorders to compare.

I brought along my Wingert Model E tuned to G Wahine (D G D F# B D), a great old slack key tuning. Doug kindly hooked up his Schoeps CMC 6 mic bodies with his MK41 supercardioid capsules, one into his Sound Devices, and one into the Fostex. Then we rigged the Zoom and Edirol on stands to bring them close to the same position. Here’s what the setup looked like:

and here’s a shot from over the mics and recorders:

The Schoeps are directly over one another, so the bottom one disappears in this overhead shot.

In some rooms, this setup might not be tight enough to give an accurate comparison, but Doug’s studio is very well treated with broad band absorbers, so the sound is clean and even in most locations. Doug’s room is also extremely quiet, so we got some nice long “tails” as the last note of the clip died away. This will give you a chance to compare the internal noise levels of the different recording chains. One embarrassing caveat – we left the Edirol R09 in MP3 mode instead of 44.1 wave, so that little guy may be suffering some quality degradation. We didn’t realize our error until we’d used up all our time for the evening. Apologies to Edirol and R09 fans.

After the recording session, I brought the clips into my Adobe Audition 3.0 where I trimmed them as accurately as I could to the same starting point and length. (Once again I forgot to “clap” the start of each clip to get a synchronization point – the learning never ends.) I converted the H2 and R09 clips to mono by using the louder of their two tracks. Then I used AA3’s group normalize feature to bring them to the same average loudness. Loudness differences have a tremendous impact on the listener’s sonic evaluation, so I wanted to level the playing field in that aspect. I think average perceived loudness is more useful than peak normalization in this situation, and after processing I listened to the samples on my Dynaudio BM 6 monitors and thought their levels were extremely close.

Now for the samples. Just for fun I’ll post them blind, so you can download them and compare without prejudging. These are .wav files and fairly large, but we wanted to preserve the fidelity so you can make a better comparison.

Sample 1
Sample 2
Sample 3
Sample 4

Now after giving a good listen to these clips, you can see the key here and evaluate the results. I hope you find these comparisons useful, and that you’ll leave a comment or send an email sharing your impressions.

As always thanks a ton to Doug for being so generous with his time, space, and gear.

I definitely don’t need another recording device around here, but my Recording Gear Acquisition Syndrome is not blunted by logic. The positive comments on various guitar forums piled up until I couldn’t resist the pressure. I had to have a Zoom H2 recorder.

I bought mine slightly used on Ebay. I saved a few bucks but even at the street price of $199 this is a pretty easy purchase to scrape up. Taking the thing out of the box, it’s pretty unimpressive – light and flimsy rather than solid and sturdy. The membrane switches gave me fits until I figure out that I should use my big fat finger instead of a delicate little touch with my fingernail.

Naturally I have to do a comparison test between this little recorder and the PC rig. Here’s a picture of the setup I used:

The mics are a pair of Schoeps CMC6 bodies with MK41 caps, in a pretty careful 90 degree X/Y. The Zoom is as close to the same location as possible, using the front mics in 90 degree configuration.

I recorded my Martin OM-18GE in drop C, doing a chorus of “Silver Threads Among the Gold.” I’m posting the recordings without trying to encourage a blind test. I posted .wav files instead of mp3s, so the downloads will be a bit long, but you can do a careful comparison.

Schoeps

Zoom H2

I think anyone can hear a difference between these two samples, and I certainly prefer the Schoeps track, but if you add up the cost of duplicating the Schoeps->John Hardy->LynxTwo chain and compare it to the cost of the Zoom, well, that Zoom doesn’t sound too bad after all.

I also tested the H2 as a PC interface. The supplied USB cable and power adapter, along with the silly looking little plastic tripod stand, had me ready for some kitchen table recording in no time. One down side to this use, I have to go into the menu and setup the USB link every time I turn the H2 on. Not a big deal, but I wouldn’t mind if the unit could remember where I left off.

I don’t have any samples of this use of the H2, because I got wrapped up in doing multi-track experiments in Audacity and Reaper, but I haven’t come up with anything I am willing to make public yet. But I can say that the H2 works as a stereo USB mic with no hassle beyond the menu tweaking.

I’ve held on to my old minidisk recorder for a number of years, but it looks like I don’t need it anymore. This new recorder is going to get a lot of use around here.

When I read about preamps at various internet forums and newsgroups, I get the impression that microphone preamplifiers are a significant variable in the recording chain. And yet, when I’ve compared preamps, I don’t notice that much difference. Well, I do notice a difference if I crank the gain all the way up. Less expensive preamps tend do be noisy in their upper gain ranges. If I’m using my old faithful Beyer M260 ribbon mics, I need all the clean gain I can get from my John Hardy M1 mic pre. But if I am using a condenser mic with plenty of output, the mic pre is operating in the middle of its range, and I don’t hear much difference between a decent $150 unit and a decent $1500 one.

Now I know that preamps are used as effects, either blatant or subtle. The blatant ones are inexpensive units with a starved plate tube glowing prominently through some grillwork and a “drive” control to mix distortion generated by this tube into the signal. The more subtle ones often refer to various recording consoles as their inspiration, claiming Neve-like or API-ish qualities. I’ve never experimented with units like these. There may be huge differences between preamps when they’re used on vocals, drumsets, electric guitar amps, or exotic percussion, I just wouldn’t know. My focus is always on simple solo fingerpicked acoustic guitar recordings, where accuracy and clarity are my goal.

Many preamps aim to be accurate. The classic description of an accurate preamp is “a straight wire with gain,” an impossible achievement but an easy ideal to visualize. Product literature and user comments include terms like detailed, musical, natural, transparent. Inferior versions of these accurate preamps are described in internet forums as flat, boring, or two dimensional. Since I have a few preamps around these days I decided to try to do some comparison tests. As always with comparisons like this, the source material is a key issue. I decided to try to run one microphone through all three preamps at once, so the input signals would be the same. Making this connection is fraught with problems. If I connect the mic directly to the three inputs, the input impedance seen by the mic will be quite low, and may affect the mic response. If I use a transformer splitter or active buffer/splitter, the sonic signature of the splitter will be stamped on all the samples. My decision was easy, though, because I already have a box that lets me rig up a passive connection direct to the three inputs. If the mic response is affected, I’ll assume (until I’m shown otherwise) that the response is still the same for each preamp.

The key to this setup is a Coleman Audio LS3 switch box. I normally use this box to select between my headphone amp and monitor amp, but since it’s a completely passive box it works to route inputs or outputs equally well.

The three preamps under evaluation are the John Hardy M-1 as mentioned earlier, along with an FMR RNP and an M-Audio DMP3.

For the first test, I selected an Audio Technica AT4041 small diameter condenser mic. I routed it through the Coleman LS3 to the left channel of each preamp, then connected the left output of each preamp to an input of my LynxTwo C. I matched the volumes rather roughly using pink noise generated by Adobe Audition 1.5 and the metering on the Lynx software mixer. I set up a multitrack session in AA 1.5 to record three mono tracks from the three preamps. I positioned the AT4041 about 12″ from the 12th fret of an Epiphone Masterbilt EF-500M tuned to “drop C” tuning – CGDGBD low to high, and played a brief bit of noodling. After I listened to the tracks I realized I had not matched the levels well enough, so I normalized all the tracks to -3db. Here are the three sample tracks, mono 44.1/16 wave files:

Sample 1
Sample 2
Sample 3

Finally, I thought I would include a comparison with a dynamic mic as the source. It would require more gain from the preamps, and might be useful to folks who only have handheld dynamic stage mics in their collection. This time I used an Electrovoice RE16, connected as before. Again I set levels using pink noise and the Lynx software mixer, then recorded in a multitrack AA 1.5 session. This time the level matching was more accurate, so I didn’t feel the need to adjust the levels after recording. Naturally the performance is different from the first recording, AND THE ORDER OF PREAMPS IS DIFFERENT:

Sample 4
Sample 5
Sample 6

I hope you’ll download these and give a listen. Does one track in each set stand out from the others? Is one more transparent, another lifeless? Can you tell them apart? Perhaps you’d like to know which sample was created by which preamp? Click here for the key to relate the samples to the preamps used to create them.

PS – After I posted these, and after I sold my FMR RNP, people pointed out that the DMP3 samples were high-passed – that is, the DMP3 LoCut switch was activated, causing a shelving rolloff -3db at 72hz, 18db per octave. This may affect the comparison for some listeners and some playback systems.