L1® Model I
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Announced March 29, 2007, the L1 Model I replaced the L1 Classic. The L1 Model I is RoHS compliant for release in Europe but functions nearly the same as the L1 Classic. Distinguishing features of the L1 Model I include orange labels on the back of the power stand and on the line arrays. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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How to Tell the Difference Between Bose Portable PA ModelsThis is how to tell which L1®, S1 Pro, or F1 unit you have.
Compatibility with Other Members of the L1® Family of ProductsCylindrical Radiator®s Cylindrical Radiator®s are not interchangeable across modelsSpecifically (and without exception)
T1 ToneMatch® Audio Engine, T4S/T8S ToneMatch® Mixers
PackLite® power amplifier Model A1
B1 Bass Module
B2 Bass Module
DocumentationDownloads
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Input Section
Entire Input / Output Panel
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Channels 1 & 2
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Channels 3 & 4
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Output Section
Orange Label
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Cylindrical Radiator Sections
L1® Model I L1 Cylindrical Radiator® loudspeaker top and bottom sections showing orange L1® labels.
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Boot
Note the 'flange' at the back edge of the boot (appears at the bottom of the silver colored recess). This prevents you from inserting the L1 Classic Cylindrical Radiator into the L1 Model I Power Stand.
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What do the LEDs mean?
Signal/OL LEDs: Channels 1 and 2
There are two LEDs on the PS1 Power Stand (Classic) / Model I near the Trim knob labelled Signal/OL -- one for Channel 1 and another for Channel 2.
These LEDs indicate when the signal level channel's preamplifier reaches certain important thresholds. The trim controls located near the LEDs adjust the amount of gain in the preamplifier.
- The LEDs turn from off → green when the signal level exceeds a small amount.
- The LEDs turn from green → red when the signal reaches a level that's about 10 dB below a level that would clip the preamp and cause objectionable distortion.
When the LED is off (but you are playing an instrument you think is connected to the PS1 or singing/talking into a microphone you think is connected): Increase the level of the trim control. If the LED still does not turn green or red, check instrument/microphone and cables to the PS1.
When you see green only: This indicates that there's some signal in the channel but not enough. While singing or playing the loudest you ever plan to in the performance, increase the trim level until the LED is only flickering red. This is the optimal gain.
When you see red most of the time: Decrease the trim level until you see only flickering red. This is the optimal gain.
Phantom Power LEDs: Channels 1 and 2
The LEDs near the Phantom Power button are either off or red when phantom power is turned on. — more information about Phantom Power
Power / System Status LED
This LED normally is a steady green when the power is on.
If it is not lit or if it is yellow/amber, contact Support.
Note: This LED may briefly flicker yellow /amber when the power is first turned on; this is normal. Within a couple of seconds, it should settle to a steady green.
Rear Panel Walkthrough
Connecting Other Equipment (inputs)
Connector Types
This section is an overview of connections you can make from a other equipment (mixer, music storage device, etc.) to the PS1 Power Stand (Classic) / Model I.
Audio equipment inputs and outputs are either balanced (three conductors) or unbalanced (two conductors). Balanced signals have the potential to be more resistant to hum and noise.
In addition different kinds of connectors are used for the input and outputs.
Here are the main types:
- XLR, male (prongs) and female (receptacles for prongs), usually balanced
- ¼ inch, male (shaft) and female (receptacle for shaft), balanced (tip-ring-sleeve on shaft) or unbalanced (tip-sleeve)
- RCA, male and female, always unbalanced
- 1/8 inch mini (male and female), balanced (tip-ring-sleeve on shaft) or unbalanced (tip-sleeve)
Cable Types and Connection to the PS1
Note: The PS1 Power Stand (Classic) / Model I Channels 1 and 2 ¼ inch inputs are unbalanced. There are many kinds of cables that will work but no connection that uses the ¼ input will be balanced because the internal connection is unbalanced.
XLR (balanced) to XLR (balanced)
This is the same as a microphone cable but is also used to connect a balanced line output to a balanced line input.
¼ Inch Tip-Sleeve (unbalanced) to ¼ Inch Tip-Sleeve (unbalanced)
These cables are prone to noise if you are running long lines (greater than 20 feet). Consider using shorter cable runs, or running a balanced line. You can use a short unbalanced cable to a DI or Direct Box (to convert from unbalanced to balanced) and run an XLR to XLR cable from the Direct Box to the Bose System.
¼ Inch Tip-Ring-Sleeve (balanced) to ¼ Inch Tip-Sleeve (unbalanced)
No issues.
¼ Inch Tip-Ring-Sleeve (balanced) to ¼ Inch Tip-Ring-Sleeve (balanced)
No issues but no better than a simple ¼ Inch Tip-Sleeve to Tip-Sleeve cable because the ¼ Inch input on the Bose System is Tip-Sleeve (unbalanced).
XLR (balanced) to ¼ Inch Tip-Ring-Sleeve (balanced)
No issues but because all four ¼ Inch inputs on the PS1 inputs are unbalanced, this cable provides no advantage over an unbalanced cable.
XLR Female to ¼ Inch Tip-Sleeve
No particular benefit to using this kind of cable as compared to the one above.
¼ Inch Tip-Ring-Sleeve (balanced) to XLR Male (balanced)
Specialized instrument cable (probably Guitar)
This is probably a specialty cable that was supplied with the instrument. It is intended for a microphone input on a mixer and will work fine with the Bose System.
XLR Female (balanced) to ¼ Inch Tip-Sleeve (unbalanced)
This is often used as a Microphone adaptor cable. Can be problematic. Sometimes you see these being used for home karaoke machines and are not suitable for professional use. The ¼ Inch input was designed for high impedance line-level inputs and may not provide enough gain for a microphone which is probably low impedance.
¼ Inch Tip-Sleeve (unbalanced) to XLR Male (balanced)
This is probably an Instrument adaptor. May be problematic. You are probably running an impedance mismatch (high impedance from the instrument to low impedance balanced XLR).
Things you can do if the signal is too high for PS1
- check to see if there is a 'pad' built-in on the mixer (most Mackie mixers have this on the panel beside the XLR outs)
- turn down the main outs on the mixer
- use a 20 dB Pad (attenuator) between the mixer and the Bose System.
Bass Line Out and B1 behavior
The behavior of the bass line out and B1 Bass Module outputs on the L1 Classic / L1 Model I / L1 Model II are based on the philosophy that adding B1 Bass Modules should give the user more dynamic range (can play louder) but should not alter the tone of the instrument, including tone adjustments made using the R1 Remote, the T1 ToneMatch Audio Engine or other tone-shaping equipment.
This philosophy is notably different from other manufacturers, who take the approach that it's okay (or desirable) that adding more bass speakers causes the instrument tone to become "bassier".
With this philosophy in mind, here is how the bass line out and B1 outputs work.
No cable plugged into the Bass Line out
| B1s connected | Output | EQ | Bass Signal Gain | Notes |
|---|---|---|---|---|
| 1 | 40Hz-180Hz | B1 specific EQ | Reference Level | |
| 2 | 40Hz-180Hz | B1 specific EQ | Reference Level -6 dB | Why? Because when you add a second B1, if you did not change the signal strength you would get 6 dB more bass relative to the mids and highs. This would alter the tone of the instrument. To keep the tone the same, while still allowing the more dynamic range (system can play louder by 6 dB) the signal level must be reduced by 6 dB. |
Cable connected to the Bass Line Out
| B1s connected | Output | EQ | Bass Signal Gain | Notes |
|---|---|---|---|---|
| 0 | 40Hz-180Hz | Flat EQ | Reference Level -6 dB | |
| 1 | 40Hz-180Hz | B1 specific EQ on Bass Line Out and B1 Out | Reference Level - 6 dB | If you are using a PackLite® power amplifier model A1 Extended Bass Package this is a total of 3 B1s (2 on the A1 and 1 on the Power Stand) |
| 2 | 40Hz-180Hz | B1 specific EQ on Bass Line Out and B1 Out | Reference Level -12 dB | If you are using a PackLite® power amplifier model A1 Extended Bass Package this is a total of 4 B1s (2 on the A1 and 2 on the Power Stand) |
With More Than 4 B1s
The Power Stand does not measure the exact number of PackLite® power amplifier model A1s, so there is a slight error if you use anything but 1,2, or 4 B1s.
For 6 B1s you will be 3.5 dB bass heavy, for 8 B1s it'll be 6 dB heavy.
B2 EQ
Bass Line Out: Model II post firmware 1.4 with System EQ 1.04
September 2012
- Bose released Model II Power Stand Model II firmware 1.4 with System EQ 1.04 to support the B2 Bass Module with the three position Bass Level Switch ( + Normal - ). Note: Support and behaviors for B1(s) is unchanged.
- The behavior of the bass line out with the B2 Bass Module Bass Module outputs on the Model 1S and Model II are based on the philosophy that adding B2 Bass Modules should give the user more bass output immediately. This changes the tonal balance as soon as you add a second B2 using an PackLite® power amplifier model A1 connected to the Bass Line Out. This is unlike the behaviour with B1 bass modules where the signal is attenuated as you add more B1s to maintain the tonal balance at lower volume levels.
- Note: If no bass modules are detected at the Bass Module Output the Bass Line Out EQ will be set to the B2 curve with the B2 switch set to Normal.
- — Source Craig-at-Bose
No cable plugged into the Bass Line out
| B2 Bass Modules connected | Output | EQ | Bass Signal Gain | Notes |
|---|---|---|---|---|
| 1 | 40Hz-200Hz | B2 specific EQ as set by the B2 Bass Level Switch ( + Normal - ) is present at the Bass Module Out and the Bass Line Out | Reference Level | There are three B2 EQ settings possible using the B2 Bass Level Switch ( + Normal - ) |
Cable connected to the Bass Line Out
| B2 Bass Modules connected | Output | EQ | Bass Signal Gain | Notes |
|---|---|---|---|---|
| 0 | 40Hz-200Hz | B2 EQ as though B2 attached and B2 Bass Level Switch set to Normal position | Reference Level | This presents the B2 EQ with the B2 Bass Level Switch set to the Normal position. (No resistance detected between the 2+ and 2- pins of an NL4 plug) |
| 1 | 40Hz-200Hz | B2 specific EQ as set by the B2 Bass Level Switch ( + Normal - ) is present at the Bass Module Out and the Bass Line Out |
Reference Level | If you are using a PackLite® power amplifier model A1 Extended Bass Package this is a total of two B2s (one on the A1 and one on the Power Stand) |
Powered Subwoofers
The Model II is an integrated system that supports Bose B1 and B2 bass modules. Connecting powered subwoofers to the Model II Power Stand Bass Line Out is not supported because EQ curves for the B1 or B2 are present at the Bass Line Out. This may or may not result in good results with a powered subwoofer.
If you want to use a powered subwoofer, connect your signal source to the subwoofer and connect the subwoofer high pass filter output to the L1® (any model).
Output if no B1 Bass Modules detected at the Bass Module Output (powered output) the signal at the Bass Line Out is:
- 40-180 Hz with B2 EQ applied if you have the current L1® Model II Power Stand Firmware Updates
- If you do not have the current firmware the signal at the Bass Line Out is: 40-180 Hz Bandpass (that is: NO B1 EQ) [2]
- The system Crossover for the Cylindrical Radiator®s is 180 Hz
If one or two B1 Bass Modules is detected or emulated using resistors across NL4 2+ / 2- pins
- 40-180 Hz with different EQ curves
- The system Crossover for the Cylindrical Radiator®s is 180 Hz
For details on how to do this see: Activating B1 EQ Curves and Using a Different Sub
- Note — Operation of the B2 with the Model I/Classic is only supported with the B2 Bass Level Switch set to Normal.
- See: Is the B2 Bass Module Compatible with the L1® Classic or Model I
Bass Module Output (powered output)
For the sake of those attaching third party passive speakers (an unsupported application), the output characteristics are the same as for the the B2 Bass Module (section immediately above).
- ↑ MikeZ-at-Bose talks about Model I in the Bose Community Message Boards
- ↑ Hilmar-at-Bose intelligent crossover
A) When there are no bass sources attached, lower the crossover and try to get as much bass out of the L1 as is reasonably feasible (110 Hz) in this case
B) If there are bass sources bring the crossover up to 180 Hz (where the L1 starts to get really efficient) AND adjust the bass gain so that the overall spectral balance is maintained no matter how many bass sources are attached.
Original Source - Hilmar-at-Bose
Use the proper cables
Warning - Use Blue B1 Cables NL4 cables with your L1 Classic / L1 Model I / L1 Model 1S L1 Model II
If you are using a B1 Bass Module with your Power Stand it is ESSENTIAL for proper operation that you use the BLUE cable supplied with the B1 Bass Module or B2 Bass Module. This is required so that the L1 Classic/L1 Model I/L1 Model 1S/L1 Model II Power Stand can correctly identify when there are bass modules connected to it and if so, how many.
Please click the picture above for ordering information.
- Note
- The B2 Bass Level Switch will not change the sound of the B2 Bass Module if you are not using the correct cable.
See: PS1 Power Stand / Bass Line Out for details about how the Power Stand adapts to the number of bass modules are connected to it.
You may also use high quality NL4 cables (four conductor cables).
Alternate and longer cables for B1s
Height
The fully assembled height of the L1 Model I is 83 inches. (211 cm)
Clearance required to assemble is approximately 86.5 inches. (220 cm)
Phantom Power
Hilmar-at-Bose posted a great message about phantom power (and why the Bose system is 24 volts)[1].
Let me add some technical ramblings to the 48/24 discussion. Condenser microphones require phantom for a couple of reasons
a) power an internal pre-amp
b) supply polarization voltage to the capsule
c) run an internal DC-DC converter that in turn fuels either preamp, capsule or both
Most condenser mics fall in category a). In this case, reducing the phantom from 48V to 24V has virtually no effect. In theory you can get higher voltages out of a 48V supply, but at this point you would clip the input of you mic preamp anyway.
In category b), the effect of dropping the phantom is that the overall sensitivity of the mic goes down by 6 dB. On the other hand, the max SPL goes up by 6dB. In general, you will simply have to turn up the trim a little more, but there shouldn't be any other effects.
Case c) is basically hit or miss. Either it works just fine or it doesn't work at all. I don't think there is any in-between.
Again, most mics these days fall in category a) and that's one of the reason why the the International Engineering Consortium (IEC) in it's standard 61938 (1996) in section 7.4.5. explicitly recommends
- quote: Although 12V and 48V systems are still in use, 24V systems are preferred for new developments
and that's why we've chosen 24V.
Compared to the L1 Classic and L1 Model II
Ken-at-Bose
- The Model II system plays as loud as the Classic or the Model I.
- Hi Folks,
- Here and in a few other areas, there's been a good discussion about volume levels in the L1 classic vs the Model II.
- I think there are two separate issues:
- How LOUD can the Model II play vs. the Classic or the Model I?
- If you set trim and channel volumes on the T1 similarly to the Classic, will you hear the same sound level?
- As to Question 1, The Model II system plays as loud as the Classic or the Model I. Moreover, the Model II is no more or less susceptible to microphone feedback than the Classic of the Model I.
- Question 2 is being answered thoroughly in other threads. My take is that the Model II and the Classic are two different products in the same family. There are some differences in how the gain staging is done. The best course in my opinion is on both units to set the trim levels and leave those alone, then use channel and master gain to bring the level to the desired amount. Again, there's no difference in the maximum sound levels.
- Ken
The maximum output volume of the L1 Classic and the L1 Model I are virtually identical.
In the L1 Classic, the L1 Cylindrical Radiator® loudspeaker is powered by two (2) 250 Watt amplifiers. In the Model I, the L1 Cylindrical Radiator® loudspeaker is powered by one (1) 250 Watt amplifier. Both the Classic and the Model I use a second 250 Watt amplifier to power one or two B1 bass modules.
Although these numbers serve as a point of reference they do not tell the whole story. During the design of the L1 Model I the impedance of the L1 Cylindrical Radiator® loudspeaker was lowered. As a result of the lower impedance, a single 250W amplifier now powers the system to within 1.75 dB of the max SPL of the L1 Classic. Several other changes were made to the signal processing and acoustical sections to further reduce this small difference. Particular attention was paid to this change and many A/B comparisons were conducted by Bose to confirm that there was no significant audible difference between the two systems.
- ↑ Hilmar talks about phantom power voltage 24 vs 48 volts