Hi Folks,

Yesterday, as planned, we did another round of testing of our Traditional Music System.

We had 4/5 members of the wonderful bluegrass group Bow Junction (http://www.bowjunction.com) here at our Live Music Listening Room at the Bose Reservoir Building. This is a nightclub/small-auditorium sized performance space we use as our live music laboratory.

Bow Junction purchased three Cylindrical Radiator(r) speakers more than a year ago now and use them in a variety of situations. Bow Junction (minus upright bass player who was ill):

Russ Aufertin - Guitar
Kathy Barnes - Fiddle
Lina Magoon - Mandolin
Pete Ocom - Banjo

We were also joined by banjo player extrordinaire Rich Stillman, and guitar great Geoff Bartley. Rich has been helping us learn about the needs of traditional music players. Geoff, who runs a famous traditional music weekly jam here in the Boston area, is also Tom Paxton's playing mate, and designed the new Tom Paxton Signature Model Guitar. (Tom Paxton will receive the highest honor from The Folk Alliance in January -- The Lifetime Achievement Award -- HOORAY TOM.)

Our goal was to explore microphone spacing, player comfort, and microphone type in our work over the course of about three hours. Steve, Brendan, and I, all of the Bose Live Music Technology Group were there to help and listen.

In the course of the next several posts, I'll describe in pictures and words what we found from my perspective. I'm sure that some of the other participants will add their voices to this thread, and as always, we welcome yours.

Here's the Traditional Music System setup with the notes added.

Here's a link to the Sketch in case you want to review it, edit it, printi it, or share it with others.


-- click image to make changes to the live version --

Codes:
Orange numbers are Systems and Inputs using those Systems.
Small numbers are Channels on the Systems.
Green numbers are for general notes about the Sketch and connections to non-Bose gear.

Quoting Ken-at-Bose from The Sketcher

quote:

Spacing of mics should be about 30 inches (75 cm).

Microphones successfully tested are: Shure KSM44’s on cardioid pattern (there is good reason to believe they will also work well on figure eight pattern but this has notbeen tested); Audio Technica AT4033, and AKG 3000-B. All can be purchased at good prices at Musician's Friend.

Microphones should be "toed in" by about 10-15 degrees: in other words,should be turned so that their diaphram is pointed a little in towards the center rather than straight back.

Cylindrical Radiator(r) speakers can be "toed in" too. Point them in toward the center of the audience 10-15 degrees. This will provide a little more foldback to the players so they can hear their mix a little.

There is reason to feel that the upright bass might be better off plugged directly (via pickup) into system 1 or 2 rather than go through the mics. The reason is that it is often difficult for the bass to be "choreographed" well enough relative to the mics given its size. This has not been tested and so remains a question mark.

This message has been edited. Last edited by: Ken-at-Bose,

Here's a picture of Bow Junction at the beginning of the test, just getting warmed up.

Recall that in traditional music, amplification is often viewed as an evil necessity. Many players would prefer it if they could magically just play unamplified and somehow have their audience hear them clearly.

The rapid falloff of sound of their instruments (the same as for conventional speakers) prevents this, however. If they just play "au natural" it may be glorious for the players, but it's not for the audience -- it's not loud enough (except perhaps the front row.)

[Here's Geoff Bartley explaining a point to the musicians. Geoff filled in on Bass: more on how we amplified that in a moment.]

One solution of course is to put a pickup on every instrument and give a microphone for each vocalist. This certainly works spectacularly with the Personalized Amplification System(tm) approach, but it tears at the fabric of traditional playing by pulling the players apart in space and putting them into more of a Rock 'n Roll format instead of the tight knot they love. Also, for many traditional players, putting electronics into their instrumentst is sacrilege.

A popular approach emerged for amplifying traditional and bluegrass bands where they all play into a single large-format condensor microphone which is then fed to the PA. The players move into the microphone when it's their turn to solo or sing, creating a new kind of choreography demanded by the amplification system. This approach goes a long way toward making the players happy and getting enough sound level into the audience. But there are some weaknesses. One is that the players don't hear the PA speakers and therefore don't hear the effect of their choreography: they're guessing at how their mix sounds. Another is that what's sent to the PA is a mono signal and in the audience, you hear all the instruments come from the PA speaker to which you're nearest.

Here's Steve of the Live Music Technology Group (second from left) with Brendan (left) and Rich Stillman, talking to Kathy Barnes about our new setup (described below)>

This message has been edited. Last edited by: Steve-at-Bose,

If you try to set up one of these large "group condensers" with the Cylindrical Radiator(r) speaker placed behind the performers, you can't get much gain because the players just can't get close enough to the mic and if even if they could the difference in volume from their normal position when not soloing would be musically far to great and would sound severe and unnatural.

The brain wave for a different application of the Cylindrical Radiator speaker came on April 2nd of this year in an earlier test. You can read all about this discovery in a very interesting thread on this Message Board by clicking here,

The idea was to push the Cylindrical Radiator speaker downstage to the lip, where the extraordinarily wide pattern of the speaker would both cover the whole audience and wrap some sound back to the performers on stage.

Moreover, if TWO large diaphram mics were used instead of one, spaced a few feet apart, a left one feeding a speaker on the left (only) and the right one feeding only a speaker on the right, then the audience would enjoy a glorious spatiality not present in typical bluegrass amplification setups. This basic approach was tried in April and produced unbelievably satisfying results. The audience heard the band at very good levels. But with the extraordinary pattern of the Cylindrical Radiator speaker, even on the extreme right of the audience they clearly heard the speaker on the left, and vice versa, something no conventional speaker could do.

Here's a picture of the setup in the test yestereday, showing the two speakers left and right and the two Shure KSM44 mics on stage. Note that the mics were switched to their cardioid pattern, with the main lobe pointed towards the players and the null of the pattern pointed toward the audience.

The band of course totally loves this. They get to play "in the nude", tightly knit into a street corner ensemble, using their standard 'microphone choreography' to accentuate solos. They hear enough wrap around from the speakers to get a good sense of the effect of their choreography on the mix without getting so much amplified sound that it takes away from their own natural acoustic ensemble sound.

Yesterday, one of the things Brendan, Steve, and Rich set out to determine was the effect of mic spacing on the audience sound.

Here's a picture showing Brendan and Steve poised to change mic spacing during a performance, with Rich and Ken (mostly Rich) out in the audience judging changes.

What we found is that if the mics are too close, you get a very intense feeling of focus in the music, but you lose quite a bit of spatiality.

If you go too wide (we tried up to five or so feet) you got glorious spatiality but the soloist in the center got a little lost.

We ended up with a compromise of three feet (Steve may make a slight correction to this later: I did not see the final tape measurement). This gave the technicolor spatiality and the intensity for the soloist that we liked. It was a very satisfying compromise of the two extremes.

Note that the mic stand in the center without a mic on it became the players' target for their choreography. When it was their turn to be accentuated, they moved in to the tip of the middle mic stand, not into one or the other of the mics. In a real performance, this middle stand would be romoved, or a far more visually inobtrusive target would be used.

For this test, we had Geoff's bass plugged into a third system located just behind him. If we had an upright bass as is the case with Bow Junction, we would have plugged him into one of the two systems downstage. There's still a little work to do once we get down to Nashville to make sure the upright bass sounds good.

Here's the band kickin' out a song towards the end of the testing. Virtuouso Rich Stillman filled in on banjo so that Pete could come out and listen from the audience.

Toward the end of the test we tried switching to AKG C-3000 mics (also large-diaphram condensers, owned by the band) and were jolted with another surprise. Suddenly the setup was able to play much louder, about 6-8 dB, without coloration or feedback. This was a pleasant surprise. Later, I'll investigate the polar patterns of the Shure vs. AKG designs to see if I can make sense of this large difference. If the AKGs have a tighter pattern, that could explain it.

It was a beautiful day of music and testing. The band was wonderful and very helpful. They played great. Rich and Geoff were great as experts in this field. Here's a group picture of the test group at the end of the session.

We all look forward to answering your questions and thinking about your comments. I believe the band is already reading this Message Board and we're likely to hear from them.

We would recommend this setup without hesitation for traditional groups wanting to play in a natural way to audiences up to several hundred. We believe it is a setup with an unprecedented suite of benefits for both players and audiences.

quote:

Originally posted by Ken-at-Bose:
Toward the end of the test we tried switching to AKG C-3000 mics (also large-diaphram condensers, owned by the band) and were jolted with another surprise. Suddenly the setup was able to play much louder, about 6-8 dB, without coloration or feedback. This was a pleasant surprise. Later, I'll investigate the polar patterns of the Shure vs. AKG designs to see if I can make sense of this large difference. If the AKGs have a tighter pattern, that could explain it.

I have been looking at the graphs for these two mics. My prediction? You are in for a shock.

By inspection, the AKG C 3000 B would best be described as a "wide cardioid", or maybe even a "real world omni". Narrow it ain't.

The Shure KSM44 seems to be cardioid at lower frequencies, trending toward hypercardioid at higher frequencies. Definitely the narrower device.

I noticed the peculiar "double dip" in the HF of the Shure. The AKG is a bit of a roller coaster too, but much smoother, and over a much wider frequency range. Also, the AKG is specified for phantom power of 9-52 volts, while the Shure calls for 48 volts. I assume you were powering both from the PAS at 24 volts?

However, my real question is not which mic, but which pattern? If I were in a situation where there is no sound behind the mics, but a lot of sound right beside the mics, I would reach for a figure-8 (bi-directional) mic. Almost any one you select has a perfect broadband null at 90°. Doesn't that make sense in this application? Am I missing something?

I am assuming the arrangement is:


............X....X.X....X............
L1 ---------- M1 --- M2 ---------- L1


Where Xs are performers, L1s are speakers, Ms are bi-directional mics, and periods make the ASCII art work (I hope).

then I would think that: The performers are still getting pretty good monitoring off the speakers so they can have some confidence about what is happening in the house. They have little enough monitoring off the speakers so that they are still working acoustically, They have any reasonable gain available to them, including the gain required to be heard over the CD launch party.

I am told that the Live Music Listening Room is a pretty good sounding space (apparently, somebody named "Jacob" had something to do with the acoustics). Do you think this approach will still be valid in some of the barns (literally) that we must use in real life?

Mike

Hi Mike,

(Happy to stop calling you MTM).

Well DANG IT, you're right about the figure eight. I should have thought of that! We will definitely try this next time out (which will be live ammo, in Nashville). Very nice insight.

As far as our room vs. reality, we deliberately did NOT make our room deluxe. We made it average, on purpose. I feel confident that the results will translate. If we bomb in Nashville, I'll be the first to admit it.

Is there any chance I could get you to post the polars for the two mics we used if you've already dug them up?

(The Live Music Listening Room was designed with the Auditioner(r) system, where you can hear a room before it's built. Still, I designed it to be average, not special. On purpose.)

quote:

Originally posted by Ken-at-Bose:
Is there any chance I could get you to post the polars for the two mics we used if you've already dug them up?

Coming up!

quote:

(The Live Music Listening Room was designed with the Auditioner(r) system, where you can hear a room before it's built. Still, I designed it to be average, not special. On purpose.)

Kewl! However, you did design a high performance auditorium on the Bose campus, did you not?

My first exposure to high end audio was at Franks' Custom Stereo and Sound, right beside Smalley's Electronics, and right around the corner from the junior college. They handled Quad. It had concrete floors, plaster walls, sparse furnishings, and the two Franks. Asked why it was so bleak, Frank said "If they like how it works in here, they will LOVE it when they get it home." Exceeding expectations is never a bad philosophy!

Mike

Shure KSM44 Cardioid Diagrams

AKG C 3000 B Diagrams

Here's some more info:

The final measure we liked best was 30" spread with a "dummy mic" in the middle. You can see in the picture the mic stand with nothing on it, that's what we asked the singers and soloists to play to.

Another interesting thing we tried was to "toe in" and "toe out" the mics. The best restults were to "toe in" the mics about 20 degrees each. This took the center vocalist and put him/her way out in front and allowed the harmony vocals to be panned left and right while being strong in the mix.

We turned the speakers in -- toed in -- so that some of the sound field was heading toward the band. This slight bit of monitoring did not limit our gain level too much, but it also did not help the band too much. On stage the dominant sound was from the players and you could hear a sligth bit of sound from the speakers. The players liked it, but to me it was a very slight difference.

Gain and levels. This band was terrifically consisten. Anyone running an experiment knows variation is your enemy and the band was rock solid. They played the same song for about 2 hours and every time I measured them they were about 85 dB SPL at the "placebo mic" location.

The best we could do with gain was to get up to about 93~95 dB SPL 10 feet or so in front of the band (we were on the edge of feedback the at that level). In the back of the room it was about 85 dB SPL so the band was thrilled. They said, "It's the same as up on stage? That's great!" I'm learning Bluegrass so I was pleasently surprised that they were pleasently surprised.

This particular band was not against close micing their instruments when the needed big volume increases so they are well on their way to having a number of different ways to use their systems for a variety of differnent situations.

Steve

quote:

Originally posted by Steve-at-Bose:
The final measure we liked best was 30" spread with a "dummy mic" in the middle. You can see in the picture the mic stand with nothing on it, that's what we asked the singers and soloists to play to.

How far apart were the speakers, and how wide/deep is the stage? How big is the house?

Actually, 85 dB at the "phantom mic" position and 95 dB in the first row sounds like damn fine performance!

quote:

This particular band was not against close micing their instruments when the needed big volume increases so they are well on their way to having a number of different ways to use their systems for a variety of differnent situations.

I know this is *really* hypothetical, but do you, with your experience, have any sense of the levels you might have achieved doing it the standard way? That is, each player equipped with a PAS, a good vocal mic, and a good instrument mic (all acoustic, no pick-ups).

I'm not sure how loud the acoustic could handle in SPL. We have a preset which is a 220 Hz notch so it can get good and loud.

Steve

Thank you, thank you, thank you! I just bought a large and a small diaphragm mike set yesterday, and was wondering what the best set up would be with my PAS. YThis is my first exposure to condensers, and it's taking some getting used to. My plan is to run them throught the PAS and then take the line out from ch 1&2 to my recorder.
Please keep us posted on how the mics/PAS experiments are going.

Hi Folks,

This illustration done using The Sketcher!

Here's the Traditional Music System setup with the notes Steve has provided added.

Here's a link to the Sketch in case you want to review it, edit it, printi it, or share it with others.


-- click image to make changes to the live version --

Codes:
Orange numbers are Systems and Inputs using those Systems.
Small numbers are Channels on the Systems.
Green numbers are for general notes about the Sketch and connections to non-Bose gear.

Quoting Ken-at-Bose from The Sketcher

quote:

Spacing of mics should be about 30 inches (75 cm).

Microphones successfully tested are: Shure KSM44’s on cardioid pattern (there is good reason to believe they will also work well on figure eight pattern but this has notbeen tested); Audio Technica AT4033, and AKG 3000-B. All can be purchased at good prices at Musician's Friend.

Microphones should be "toed in" by about 10-15 degrees: in other words,should be turned so that their diaphram is pointed a little in towards the center rather than straight back.

Cylindrical Radiator(r) speakers can be "toed in" too. Point them in toward the center of the audience 10-15 degrees. This will provide a little more foldback to the players so they can hear their mix a little.

There is reason to feel that the upright bass might be better off plugged directly (via pickup) into system 1 or 2 rather than go through the mics. The reason is that it is often difficult for the bass to be "choreographed" well enough relative to the mics given its size. This has not been tested and so remains a question mark.

I had in interesting discussion with a (conventional) (very good) sound man yesterday about bluegrass. I picked up at least two interesting tidbits:

First, he has used a wide range of microphones for "single mic" applications. The best results have been with the AKG C 414 XLS, with one important caveat: It is too good. Although it is the most musical mic and provides the best gain before feedback, it also can place the "quiet" Honda generator (located 100' away, the length of their mains power cable) firmly and squarely in the mix. Been there, done that. He has had the best all-round luck with Apex microphones, which are one of the many knock-offs of the big names, at 1/10 the price. He cautions that there are lots of untried microphones on his list, but this is his experience so far.

< http://www.apexelectronics.com/ >

Standard disclaimer: No affiliation with Apex in any way. I've never even touched the product, much less tried it. Just the reporter, here.

Second, the only time he has had "single mic" techniques work is when the performers are using IEM. Removing the sound entirely from the stage is the only way to get sufficient gain before feedback for adequate levels to the back of the house. (Remember this is the conventional sound guy talking.) Even then, it is just barely acceptable, and always on the verge of feedback, etc. etc. We're not talking big houses here, either.

Ken Jacob. This might be some food for thought for your big show at the end of the month. Can you discuss any details about what you are planning? Will you have a demo space? Will you have the "two mic" system set up? How about, to pick a number, a 5-PAS system available to try?

I really think that what the bluegrass folks want to do is sound natural and acoustic. The only way they have ever heard that happen is by the "single mic" technique, in spite of its severe limitations. If they were given the opportunity to try the standard PAS technology with mentors available to ease them into it, they would be digging for their wallets.

Referring to the Sketcher layout:

The mics are a little further upstage than I had imagined. I think it would be fun to experiment with mic/speaker placements that would favour a figure of 8 mic. The set-up shown here would probably be best served by a super-cardioid design. Whatever the final set-up, it's important to get the speakers in the null.

With a design for figure of 8 mics, the speakers could be moved upstage somewhat, which would improve the cylindricality of the low frequencies (if I am interpreting another thread properly).

About that bass. I am a little worried about inserting a pick-up into things. I'm a little more worried about having the bass coming from far stage left when the bassist is stage centre.

First stupid idea:

Remove the B1 from the stage right side, and move to the left. Attach one of the clip-on style mics to the bass, and feed to a small mixer. Take mixer feeds to SL and SR L1s. Theory: All the bass notes now come from one location, but both sides of audience have the benefits of the bass harmonics. Localization improved.* The higher frequencies are separated by lots of space, so most, if not all, interactions should be inaudible.

Second stupid idea:

Attach above clip-on style mic to bass. Run to third PAS upstage in conventional position.**

Admission:

I don't like either of these much.

To wit:

*Hmm, upon re-reading, not really. The bassist will sound to be house left for folks house left, but will be seen to be centre right.

**Now the bass leaks back into the stage centre mics.