DJ

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Placeholder until we get a nice picture
This is guide for people who use their Bose Portable PA in Mobile DJ, KJ, VJ applications.

In addition to the notes below that apply to Mobile DJ, KJ, VJ shows, check out:


How do I add more than two B1 Bass Modules to an L1®

You can have up to two B1 Bass Modules connected to an L1® Power Stand.


B1s: How do I place them, single double, quad

Classic This information is applicable to the L1® Classic
L1 Model I This information is applicable to the L1 Model I
L1 Model II This information is applicable to the L1®  Model II
B1 Bass ModuleThis information is applicable to the B1 Bass Module
B2 Bass ModuleThis information is applicable to the B2 Bass Module

In response to: "where and how is the best way to place the B1; single, double, and quad"

It Depends

I'm planning to expand the wiki article Bass Outdoors to try to be as comprehensive about indoor and outdoor bass placement issues as I can be. Until I publish that, the short but annoying answer is of course, "it depends" and the slightly longer, but still unsatisfying answer is, "results will vary from case to case in ways that even the best acousticians can't anticipate." But you'll often find recommendations on the web or even in technical journals by folks who have only considered a subset of the factors that contribute. The authors may not know about the other factors or, more likely, they may be hoping that those other factors can be ignored. The temptation to extrapolate beyond the part that one grasps is almost irresistible. Hope springs eternal. One wants to give a satisfying answer, even when it is out of reach.

This is not as hopeless as it sounds, because there is an important distinction between "what is best?", which we cannot answer, and "what do you recommend that I do?" which we should and can answer. We can also say some things about "what should I NOT do?" Here I will give you a random smattering of such recommendations and hope that they will suffice until I can give a fully organized wiki entry. It's a pretty long post, but I hope it will address most of the questions that have arisen. (It takes more time to make a shorter post. Smile ) If not, ask more questions and that will help me make the wiki entry more complete. Chris

Orientation, aiming and obstruction

Sound comes through the Bass Module grille only and then spreads out the same amount in all directions from that surface. So box orientation doesn't matter to the Bass Module sound. Sonically the Bass Module can rest on any one of its four sides and nothing will change. (Of course, for stacking, you want the "wide side down" in order to engage the nubs on the next Bass Module.) Once you pick a side to rest it on, you can aim the Bass Module in any direction you want, forward, sideways, even firing backward toward a rear wall. If you hear a change, it is because you've moved the grille relative to other Bass Modules or relative to boundaries. Don't shove the grille into a wall or into a big obstacle, because then the sound can't get out; leave at least 6 inches (15 cm) of space in front of the grille. The side of the box itself can be right against a wall, so long as the grille is not obstructed. We often start out placing our Bass Modules on the floor, sideways against the rear wall, so that the first reflections from the floor and rear wall will not change the tonal balance in the bass. (Room modes will change the tonal balance anyway, but at least we eliminate one source of variability this way.)

Arranging groups of Bass Modules that play the same signal

When multiple sources playing the same signal are spaced apart, they make an "array" which means that the tonal balance they radiate can be different in different directions. If you understand array theory, you can make this work for you, but in our case, it is safest to keep the spacings as small as we can, so that the array radiates the same in all directions. When we keep the spacing tight, multiple B1s will behave just like single B1s, only louder. What matters here are the spacings of the grilles, not the cabinets, because the grilles are where the sound comes from. The more specific suggestions that follow below rely partly on my own understanding of the theory and partly on consultation with Hilmar, who has both theory and a lot of experience to guide him.

Two Bass Modules

For two B1s (or B2s), we prefer to stack them on their wide sides, mostly because this takes the minimum floor space. But you can place them side by side or even face to face, leaving 12 inches (30 cm) between grilles (because this is 6 inches (15 cm) in front of each B1). Sonically, it doesn't matter which wide side is up and the two don't have to have the same side up. Sonically you can even have one B1 on its wide side and one on its handle side, although that looks funny. In fact, for two B1s, "looking good" places more restrictions on what you do than "sounding good." I've seen two B1s placed either side of an L1 on the PS1, and that should work fine acoustically. In any arrangement where the grilles fit completely within a 30 inch (75 cm) diameter sphere, your two bass modules will act like a single one, only louder. Note that spacing two B1s on the floor with the L1 Classic or L1 Model I Power Stand between them does not meet this criterion. That arrangement would reduce the mid-bass that radiates to the left and right sides.

Four B1s

For 4 B1s, we are most likely to stack all 4 on their wide sides, but sometimes we make two stacks of two, side by side. The stack of four takes up the least floor space, but it radiates a little less mid-bass upwards, which has not been a problem and might be beneficial. We don't lay all four in a line on the floor on their wide sides, since we expect this to weaken the midbass that travels left and right toward other band members or audience at the sides. You could probably lay all four in a line if you rest them on their handle sides, so that they make a short line. If you use the 2x2, keep the two stacks adjacent to avoid possibly weakening the mid-bass to the sides.

Locating the Group of Bass Modules

Where to locate the group: If the group of B1s is far from its L1, the lows will come from one place and the highs from another and this is harder for everyone to hear clearly. More than about 5 feet (1.3 m) of separation is probably beginning to compromise your spatial quality. It's best if you can keep the B1s adjacent to or within a foot (30 cm) of the PS1. Since our preferred arrangements are stacks of 2 or 4 B1s, we also like to aim those stacks sideways and place them against the rear wall if we can, because this minimizes unwanted array effects with the first reflections. But we don't hesitate to aim the stacks forward when the best appearance is more important. In this case, we keep the B1s as close to the back wall as the connectors allow, but being careful not to stress the cables by bending them too sharply against the wall. Although we prefer to keep the B1s as close to the rear wall as we can, there are times when this is just not an option. In such cases, we try to get 7 feet (2.1 m) or more from a rear wall as a second choice because, in the 2-7 foot (0.6-2.1 m) range, the reflection from the rear wall tends to reduce some of the bass frequency range in the audience (an interference effect). Sometimes we have no choice but to place B1s in that 2-7 foot (0.6-2.1 m) range and we just live with the minor reduction in bass, perhaps compensating with a bass tone control boost.

Other variations: It's okay to raise the B1s on short risers if you like, but I don't know of any reason why this would always sound better or worse, just different. Floors and walls are not perfect reflectors of bass[1], but I have no different recommendations to make due to this source of variation.

It Depends

Although the above suggestions describe our default arrangements, they don't always yield good-sounding results. The factor that we can't really control or understand easily is the room. Rooms often cause very uneven distribution of bass and there is no universal method of cure. Sometimes a different speaker placement seems to help, but what helps for one listener usually makes it worse elsewhere. It's easy to fool yourself and it's easy to fuss endlessly without finding a good solution. We try not to fall into that trap. If one or two alternatives don't cure the problem, we give up and move on.

There are only a few techniques that we think are likely to help. First, if there is too much bass, we might try to fix that with a tone control reduction before moving anything, since, if it works, we will have higher maximum bass output available to us (because the bass amp is working less hard to give the right amount of bass). If a bass control adjustment doesn't straighten out the problem we hear, we might move the stack closer to or farther from the nearest corner. Closer sometimes increases bass while farther sometimes reduces it. (That's the simplified theory, anyway.) But proceed with care: the change the musicians hear will probably be different from the change in the audience. Make sure you know who you are trying to improve the sound for. The last thing we might try is a different arrangement, say switching from a stack of 4 to 2x2. If these few alternatives don't give a clear improvement (and they usually don't), we think it's time to shrug our shoulders and get on with the show.

Who Wins?

Ultimately, we have to be willing to accept that often the room will "win" and we won't get the ideal bass response. This will be true for any bass system, not just specifically for the B1. There is no point in worrying about this--we do what little we can to avoid the worst and then concentrate on giving a good performance. If we do that, the L1 will make sure people enjoy the sound, even when the bass isn't all that we'd like it to be.

 


How do I protect the L1® components - Cases

Hardshell Cases — this page is about protecting the L1® components while in transit.

How do I connect an Analog Stereo Source to an L1®

Backing Tracks — This article covers connecting devices like CD, DVD, mp3, iPods to your L1®

How do I connect a DJ or VJ Console to a Model I

Connections / DJ VJ Computer to Model I— This article covers connecting devices like a DJ or VJ console to your L1®

How do I connect a single T1 ToneMatch® Audio Engine to two L1®s

We have a comprehensive article on how to do this that covers analog and USB connections.

T1 ToneMatch® Audio Engine / Stereo Output to Two L1®s

{{#Click:T1 ToneMatch® Audio Engine / Stereo Output to Two L1®s|Image:USBtoStereoL1Model I.png|250px|run a single T1® to two L1®s}}

L1® Model II: Can I run a Stereo Source to the Power Stand

A ¼ inch Tip-Ring-Sleeve connector carrying a stereo signal should not be used with the analog input on the Model II.

Even though a ¼ inch Tip-Ring-Sleeve connector can carry a stereo signal this is not how this physical connection is used on the DJ Power Stand.

The analog input on the Model II is balanced, and will therefore subtract the Left and Right signals on a stereo cable and you will hear an L-R (Left minus Right) signal in the Model II.

You cannot 'get through the gig' this way if you are a DJ or if you need to run prerecorded music or have stereo inputs.

TRSfromStereoRCAModelII.png

TRSfromStereo14ModelII.png

18stereoTo14stereoModelII.png


Using a Mixer

L1 Model II

Alesis MultiMix8USBBehringer UB1202Mackie 1202 VLZ ProNumark CD Mix-2Spirit NotepadYamaha MG82/FX

If you are using a mixer instead of a T1 ToneMatch Audio Engine use the mixer to create a mono output and send that to the Model II Power Stand Analog input.

  • If there is a stereo/mono switch then use it and send the mono output to the Model II Power Stand Analog input.
  • If there is a Left/mono output then use that and send it to the Model II Power Stand Analog input.
  • If there is no way to create a mono output then pan all your mixer inputs all the way to one side (e.g. Left) and then take the mixer for that side (e.g. Left) output and send it to the Model II Power Stand Analog input.




What is the best way to setup for Stereo

Live or PreRecorded / Stereo and *-Mono — The engineers at Bose conducted listening tests with four L1®s and eight B1s. Read about the results in this article.

Can I run two L1®s in Mono

Minimum Distance Running Two L1®s in Dual Mono

Phase cancellation can be an issue if you are running Dual Mono (two L1®s from the same mono source). This can be an issue when two or more L1®s are fed the same signal.

The minimum recommended distance for two L1®s running the same signal is 20-50 feet.

Only when fed the same signal, "Interference between line arrays would be more severe [than for non-line-array speakers]. In fact, the current Bose design rules for installing MA12 line arrays recommend ... a spacing between line arrays of between 6 and 15 meters! (20-50 feet)" The same applies to the L1. - Chris-at-Bose [2] (Clarifications added by the author of the quote.)


Note: During a conversation with Chris-at-Bose, he confirmed that the recommendations above are the same for the L1 Model II. ST 15:13, 30 August 2007 (GMT-7)

  1. Floors and walls are not perfect reflectors of bass - see: B1 Bass Module / Walls
  2. See: Used 4 towers & 8 subs today in the Bose® Pro Portable PA Community


How can I connect two L1® Model Is to play the same source

Please see: PS1 Powerstand / Daisy Chain.


What is a Pad and when would I use one

"pad" is short for attenuation pad. This is a device used to lower the signal level between two other devices.  You are most likely to need a pad when using a L1 Classic or L1 Model I  and your source uses an XLR connection at line-level. For more details please see: Pad.