Bose Portable PA Knowledge - User contributions [en]

Pad

2008-09-04T12:01:33Z

BlackForestMan: /* Do It Yourself */

Q: What is a Pad?

A "pad" is short for an "Attenuation Pad".

This is a device used to lower the signal level between two other devices.

=== Padding {{PS1}} Inputs ===
We use pads with our {{PS1}}s when running a pro level +4 dBu signal (e.g. output from a mixer) to the XLR inputs on Channels 1 or 2. We want to do this because the input sensitivity for these inputs is set for microphones. To get a better match for levels between the source and our inputs, we can use a pad.

Pads can also help when connecting the PS1 Line Outs to ''semi-pro'' or ''consumer'' recording devices. If the PS1 Line Outs are too ''hot'' for the recorder's inputs, a pad can be used to prevent overdriving those inputs into (clipping) distortion.

A -20dB pad is also a good choice when connecting the PS1 Line Outs to a house PA, or other off-stage system. This would ensure that the house mixing console's inputs can handle the signal level without being overdriven into distortion, especially if the house console has insufficient built-in pads, or none at all. (Beware of the potential for Ground Loops here.)

=== Daisy Chaining {{PS1}}s ===
Another application (although relatively rare) is if you want to connect the output of one {{PS1}} to input of another. Sometimes called ''daisy chain''ing, you can connect the Line-Out of one {{PS1}} to Channel 1 or 2 of another. In that case you probably want to have a -20 dB pad inline, between the Line-Out of the first System and the Channel 1 or 2 XLR input of the second. See [[PS1 Powerstand / Daisy Chain]] for more information.

You can find separate attenuation pads like this:

[[Image:Pad.jpg]]

Cost: $20-30 on the web

Sources:
* http://www.proaudiosolutions.com/product_p/impad20.htm
* http://www.musiciansbuy.com/WHIRLWIND_IMPAD20_IMPEDANCE_CONVERTERIMPAD20.html
* You might find something like this in a local music store if they have a Pro Audio department.

This an example, and you will want to look into the details to determine if you need a pad, and the kinds of connections that are appropriate for your input device.

== More Formal Definitions ==
"attenuator or attenuator pad Electronics. A passive network that reduces the voltage (or power; see usage note under gain) level of a signal with negligible distortion, but with insertion loss. Often a purely resistive network, although any combination of inductors, resistors and capacitors are possible, a pad may also provide impedance matching."

== Do It Yourself ==
<blockquote>
A quality inline pad can be easily soldered [makes no sense to spend extra money here]:
Insert 3 resistors into your mic cable:
* 2x 470 ohms, inserted into line 2+3 [absolute value +/- 10%, but matched to less than 1% tolerance]'' (= console side, for usage between console and L1/PS1)''
* 1x 470 ohms, inserted between pin 2+3 on the console side (orig.).'' (= PS1 side, for usage between console and L1/PS1)''
</blockquote>
Source: [http://www.neumann.com/forums/view.php?bn=neumann_micrec&key=1122644079&v=f Martin Schneider / neumann Mic. Development]

References:
* [http://www.rane.com/par-a.html Rane Professional Audio Reference]
* [http://www.uneeda-audio.com/pads/ All About Pads]

[[category:Gear]]
[[category:Mixer]]
[[category:Terminology]]

B1 Bass Module / Positioning

2007-10-08T20:09:31Z

BlackForestMan: /* Locating the Group of B1s */

<table border="0">
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<td width="40%">__TOC__</td>
<td valign="top">
Chris-at-Bose wrote this article<ref>[http://bose.infopop.cc/eve/forums/a/tpc/f/867107664/m/7811035504?r=3981085704#3981085704 In search of Bass] in the {{Forum}}</ref> and encourages your improvements. Edits for formatting and subtitles done by [[User:ST|ST]] 23:17, 23 November 2006 (GMT-7)
</td>
</tr>
</table>

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 B1 grille only and then spreads out the same amount in all directions from that surface. So box orientation doesn't matter to the B1 sound. Sonically the B1 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 B1.) Once you pick a side to rest it on, you can aim the B1 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 B1s 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 B1s 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 B1s 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 B1s ====
For two B1s, 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 B1s will act like a single one, only louder. Note that spacing two B1s on the floor with the PS1 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 B1s ===
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, 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.

<noinclude>
<references/>
[[category:B1 Bass Module]]
[[category:Bass]]
[[category:Chris Ickler]]
[[category:Reference]]
</noinclude>

B1 Bass Module / Positioning

2007-10-08T20:08:06Z

BlackForestMan: /* Locating the Group of B1s */

<table border="0">
<tr>
<td width="40%">__TOC__</td>
<td valign="top">
Chris-at-Bose wrote this article<ref>[http://bose.infopop.cc/eve/forums/a/tpc/f/867107664/m/7811035504?r=3981085704#3981085704 In search of Bass] in the {{Forum}}</ref> and encourages your improvements. Edits for formatting and subtitles done by [[User:ST|ST]] 23:17, 23 November 2006 (GMT-7)
</td>
</tr>
</table>

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 B1 grille only and then spreads out the same amount in all directions from that surface. So box orientation doesn't matter to the B1 sound. Sonically the B1 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 B1.) Once you pick a side to rest it on, you can aim the B1 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 B1s 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 B1s 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 B1s 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 B1s ====
For two B1s, 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 B1s will act like a single one, only louder. Note that spacing two B1s on the floor with the PS1 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 B1s ===
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 (.3-2.1 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, 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.

<noinclude>
<references/>
[[category:B1 Bass Module]]
[[category:Bass]]
[[category:Chris Ickler]]
[[category:Reference]]
</noinclude>

B1 Bass Module

2007-05-14T08:39:18Z

BlackForestMan: /* German */

[[Image:B1Bass.gif|right]]

== Keep the B1s Together ==

If you have more than one B1 playing the same sound source (instrument), keep the B1s together. You should get as much as 3 dB more than if you have them separated. This is due to acoustic coupling. This also avoids creating [[nulls]]. You can stack them or have them side-by-side but you want to keep them together. For more comprehensive discussion about this see [[{{PAGENAME}}#Arranging and Placing the B1s|Arranging and Placing the B1s]] (below).

== Arranging and Placing the B1s ==
Chris-at-Bose talks about how and where to locate your B1s
* [[B1 Bass Module/Positioning]]
* [[Bass Outdoors]]
=== Stacking (up to four high) ===
From page 12 of the [http://www.bose.com/pdf/musicians/120VOwnersGuide/AM263976_03_120V_OG_ENG_Viewable.pdf Owners Guide]

[[Image:B1Stack4.png]]

== Check the Cables==
[[Image:B1Cable.gif]]
You may want to double check your Blue B1 cables. See [[B1 Cable Connections]]

== Rotate the Logos ==
You can rotate the Bose logo so it is parallel to the floor even if you have turned the B1 on its side.
Chuck-at-Bose said, "... Maybe it's my kung fu grip, but I've had good luck with carefully pinching the logo and pulling at these points, then rotating 90 degrees:"

[[Image:B1LogoRotate.jpg]]

Be very careful with the fine ends of the logo because they can be easily broken off. You may even try to pull up in the middle with your fingernails on the edge instead of near the ends.

== How Low does the B1 Go? ==
The short answer: 40 Hz.
But what about instruments that go lower than that, for example a five string Bass. A much better answer comes from Hilmar-at-Bose in [[Bass Frequencies]]

== Port Orientation ==
"Theoretically, port-side-up may give a tiny bit better aligned floor reflection but in practice, the difference is so small that it isn't worth bothering with.
However, I would still advise when you stack multiple B1s keep them all in the same orientation." - Hilmar-at-Bose <ref>[http://bose.infopop.cc/eve/forums/a/tpc/f/3976055944/m/9791009151/r/9791009151#9791009151 B1 Port Orientation: Hilmar's post in the Bose® Musicians Community Message Boards]</ref>

When I read this, I had to go and look very closely to find the port. It's easier to figure out that when the B1 is on it's side, port side up is same as (on the back) connection panel down.

== Longer cables for B1s ==

Unfortunately, the Speakon connector comes in three different flavors, NL2 (2-pins), NL4 (4 pins), and NL8 (8-pins). Most salespeople are not aware of the differences.
The Bose B1 requires a NL4 connector with all 4 pins connected (that's why we call it 4-wire cable).

A good source for these cables is

http://www.audiopile.net

for example

http://www.audiopile.net/products/Speaker_Cables/NL-4_speaker_cable/NL413_cutsheet.htm

If you call Mark and tell him you want the cable for the Bose B1, you will get on that is made to our specifications. You can also any custom length cable at a very reasonable price.

=== German ===
German (translation provided by [http://bose.infopop.cc/eve/personal?x_myspace_page=profile&u=8801052851 BlackForestMan])

SPEAKON Kabel gibt es in 3 verschiedenen Varianten, NL2 (2-polig), NL4 (4-polig), and NL8 (8-polig). Häufig kennt das Verkaufspersonal diese Unterschiede nicht. Das Bose B1 Bassmodul benötigt aber ein NL4 bei dem alle 4 Anschlüsse verbunden sind (daher sprechen wir hier auch von einem 4-adrigen Kabel).

Fertige Kabel in verschiedenen Längen gibt es z.B. hier:
* [http://www.thomann.de/ Musikhaus Thomann]
* [http://www.thomann.de/de/cae_1471015_lautsprecherkabel.htm CAE 14710-1,5 (NL4): hochflexibles Lautsprecherkabel, 4x2,5mm, 1,5m, Speakon --> Speakon]
* [http://www.thomann.de/de/cae_147133_lautsprecherkabel.htm CAE 14713-3 (NL4): hochflexibles Lautsprecherkabel, 4x2,5mm, 3m, Speakon --> Speakon]
dto. gibt es auch in 5m, 10m, 15m Länge usw.

In der Regel wird auf Anfrage aber auch jedes lokale Musikgeschäft ein Speakon NL4-Kabel in passender Länge herstellen können.

- Hilmar-at-Bose<ref>[http://bose.infopop.cc/eve/forums/a/tpc/f/3976055944/m/2941001112?r=8521011112#8521011112 B1 Cables]</ref>

----
<references/>
[[category:Bass]]
[[category:B1 Bass Module]]
[[category:L1™ System]]