Daisy chain L1 classic and L1 Model 1 with T1 mixer

Portable PA
1

Hi Community, 

 

I need some help.

 

I have 

1 -L1  Classic with 2 B1 

1 -L1 Model 1 with 1 B1

1 -T1 Mixer

 

2 - 50' XLR - XLR cables

2 - 50' TRS - TRS Cables

1 - Wireless Mic with 1/4" input

2 - XLR Mics (Shure sm57 and Shure beta)

 

My requirement is 

Guest size 400 - 500.

Hall is pretty big.

3 Mic Inputs.

1 Music input.

 

Now, my question how to connect these : 

I don't have a stereo requirement it's an event and not some recording or on stage performance.

My T1 mixer has only 1 output. If There was Left and Right I would not worry at all. My Issue is connecting both the L1 (classic and model1) to T1 somehow.

 

  1. Can I daisy chain L1s with a -20DB pad using channel 1 output (XLR ) of Classic to i/p of pad and o/p of pad to i/p (XLR) of Channel 1 of Model 1 (> 20' apart from L1-Classic)with T1 Mixer output connected to channel 1 i/p (TRS-TRS) of Channel 1 of L1-Classic?
  2. Keep it simple and rent a mixer with left and right channel ?

This topic may have been covered but T1 mixer is not in the mix. Hence the confusion.

Thanks for all the help in advance. 

 

Thanks again 

Best regards

Xytiz

 

 

 

2

Hello xytiz,

 

Either of your two solutions will work fine, and are exactly what my recommendations would have been.  As long as your two L1's are at least 20 feet apart, you'll minimize any phase cancellation issues (although too far apart, and some guests will almost certainly hear delay echoes.)

 

My only concern is "1 music input".  You indicate you're not worried about stereo, but if your music source is stereo you'll need to consider how the left and right channels are processed.

  • If you're using your T1, make sure you're familiar with hooking music sources such as DJ controllers, MP3 or CD players, or laptops to Channel 4/5.  This will ensure both sides of the stereo source are mixed to mono, which will be distributed to both systems.  (If you're not familiar with this, see Stereo Sources in the Bose Professional Portable PA Encyclopedia.
  • If you rent a "standard" mixer, you need to consider whether you want the stereo sides split to the two systems, or combined in the mixer and the same signal sent to both systems.  Hooking your stereo source to a stereo input will send the left signal to one system and the right signal to the other; hooking it to two separate mono channels will mix left and right and send the combined mix to both systems.

Good luck with your event!

 

Does that help?

3

Hi Fish-54

 

Thanks a lot for your time and response. 

I will go with Daisy chain option rather than renting a mixer.

I will also use channel 4/5 inputs for playing tracks etc like you suggested.

 

I had few last questions.

  1. Can I connect channel 1 line out  on L1-classic  to Channel 4 input of L1-model 1 without a -20db pad ?
  2. If Pad is necessary then with that logic does output of T1 mixer also need to be padded before giving it to channel 1 i/p on L1-classic ?
  3. I think I don't understand "line level" terminology correctly, Hence I keep asking these questions. My apologies for my ignorance. 
  4. How to connect headphones ? I can use AUX o/p for headphones ?

Thanks in advance. Even one line answers will do , I want to be sensitive to your time..

 

Thanks a lot again 

Best regards

Xytiz

4

Hello again xytiz,

 

For your additional questions:

 

"1. Can I connect channel 1 line out  on L1-classic  to Channel 4 input of L1-model 1 without a -20db pad ?"

 

With an XLR-to-1/4" cable, yes.  I have never tried it, but it seems logical.  I think the reason they suggest XLR-to-XLR with pad is that the XLR inputs are balanced and optimized for mic-level signals -- longer cables can be used without fear of interference or dB loss.  The 1/4" inputs on the Model 1 and Classic (including the ones in the center of channels 1 and 2) are unbalanced and optimized for instruments.

 

"2.  If Pad is necessary then with that logic does output of T1 mixer also need to be padded before giving it to channel 1 i/p on L1-classic ?"

 

Your logic is correct.  If you connect the T1 output to the channel 1 XLR, you probably will need the pad.  If you connect to the 1/4" on channel 1, you probably won't.  If your T1 will be close to the Classic (shorter cable) I'd probably use the 1/4"; if over 12 feet away, use the XLR with pad.

 

"3. I think I don't understand "line level" terminology correctly, Hence I keep asking these questions. My apologies for my ignorance."

 

Don't apologize -- we learn all kinds of things by asking!  I am not an electrical engineer or audio professional, just another user who has learned as I go.  Generally speaking, mic levels are weak and need lots of amplification; instrument levels are stronger but still need amplification; line-level signals are higher.  It's just a matter of closely matching the output level to what the input jack is expecting.  There's a huge difference between mic- and line-level (requiring a pad), while there's less of a difference between instrument- and line-level  (you can usually manage by turning down the mixer's output and speaker's input.  That's why they recommend setting the Model 1 / Classic volume to 3 when using a T1.)  The T1 can put out a strong line-level signal, just be sure not to overdrive your Classic's inputs.

 

There's a great explanation on Sweetwater's site here:  Differences Between Signal Levels

 

"4. How to connect headphones ? I can use AUX o/p for headphones ?"

 

Yes, since the T1 master out is connected to and L1, you'll have to use Aux for headphones.  While it does work, the T1 wasn't designed with headphones in mind, so your success will depend on your phones.  Since the phones expect a stereo signal and Aux puts out a mono balanced signal, you might experience some cancellation.  You'll just have to test them.  If you've never set up Aux before, this page has some instructions.

 

"Thanks in advance. Even one line answers will do , I want to be sensitive to your time."

 

I appreciate it.  I'm retired, so I have plenty of time and volunteer some of it here.  As always, I hope you have as much time as you think you'll need to test your combinations, and be prepared to change connectors or inputs if you don't get exactly what you need!

 

Does that help?

5

Hello again xytiz,

 

I just remembered something regarding one of your questions, regarding connecting to channel 3 or 4 1/4" on the second system rather than the recommnded XLR-XLR cables with a -20db pad to channel 1 or 2.  This won't affect you, but I thought I'd explain the reasoning behind Bose's recommendation for others reading along.

 

When the Classic and Model 1 were introduced, the T1 (and later T4S and T8S) didn't exist.  Users connected their mics directly to channels 1 or 2, and chose their ToneMatch presets with little "click switches" on the rear panel.  These presets, along with any EQ set via the remote modules, were applied after the preamp, in the Digital Signal Processor (DSP).  The channel 1 and 2 line outs were tapped after the preamp, but before going to the DSP, so the line out signals are flat and line-level.

 

The logic was that the line outs might be sent to a house system or recording console, with EQ and effects added later.  However, if the line outs were sent to a second L1, the ToneMatch presets would also need to be applied on the second system.  Since you can only apply presets to channel 1 or 2, the -20db pad was inserted to bring the signal back down to mic level for them.

 

xytiz, since you'll be applying your ToneMatch presets in your T1, you don't need to worry about them on the Classic or Model 1.  If you use channel 1 or 2 on either system set their presets to "00" (flat).

6

THANKS A TON .. 

I really appreciate your time. I will let you and the community know how the event went. It's ok 24th oct. I will plan and hook everything at home before going to the event. ANY TIME YOU ARE IN SACRAMENTO area email me(pavanmg@gmail.com)... I owe you a lunch when you are here.. 

 

Best Regards

xytiz..

7

Okay Flat 00 it is .. 

Thanks again 

Xytiz

8

So I wont gain anything if I am using TRS cable to connect to channel 1 of classic correct ? It will still behave as an unbalanced input even when the source is T1 Master output thats Balanced. 

 

So just to summarize one last time : When keeping the L1s more than 20 feet away. 

 

I will need to do the following. 

 

TRS(T1 master output) <-> TRS to XLR converter <-> XLR 20db Pad <-> XLR input of the L1 classic channel 1. 

 

If I am using another L1( Model 1). 

Then take line out on L1 classic channel 1 :

XLR <-> XLR 20db Pad <-> XLR input of the L1 model1 channel 1. 

 

Just confirming one last time. 

 

Thanks again 

Xytiz

 

9

Hi again xytiz,

 

"So I wont gain anything if I am using TRS cable to connect to channel 1 of classic correct ? It will still behave as an unbalanced input even when the source is T1 Master output thats Balanced. "

 

Correct.  However, if your distance from the T1 to the first Classic isn't that long, you could use a 1/4" TRS to 1/4" TRS or 1/4" TS to 1/4" TS cable.  Either will work fine without the pad, because a -20db pad is already built into the 1/4" center of the channel 1 and 2 combo jacks.  If you're running a long (> 12 ft.) cable from the T1 to the Classic, then stick with what you've described to use the balanced cable.

 

"TRS(T1 master output) <-> TRS to XLR converter <-> XLR 20db Pad <-> XLR input of the L1 classic channel 1. "

 

Just make sure your "TRS to XLR converter" is a simple connection converter, like this:

TRS-XLRConverter.jpg

and not an impedance matching transformer, like this:

ImpedanceMatcher.jpg

The impedance matching transformer is designed to take a mic signal into the XLR and send an instrument-level signal out the 1/4".  (Besides, the 1/4" is just a TS, not a TRS.  I assume you knew this, but again, I'm explaining for those reading along.)

 

I think you've got a great handle on what you need!

10

Hi Fish-54, 

 

Thanks a lot again. You have been a great help. 

In every sentence you write I learn something new. 

I did not know about Impedance matching transformer.

Really, thanks again.

 

Best regards

Xytiz 

11

Hi Fish-54,

 

The event went really well last Sunday. Everyone were super impressed with sound quality and output. 

Thanks a lot again. I had to keep the volume at 5  on channel 1 for L1 classic and L1 Model 1 . Keeping it at 3 was making my master volume go all the way to max on T1 mixer and I did not want it that way because there will be no room for volume increase during the performance. 

 

Fish-54 , Tell me one thing since L1s disperse sound almost 180 degrees. Can I keep them in the center of the hall backing each other (L1 classic and Model 1) to get a 360 degrees sound ?  One of the speakers can face the stage and other face the wall in front of the stage. ? I am asking about this setup because one of the speaker will server as a monitor speaker to the artists ?

As most of the time keeping behind the artists is not an option especially if its a south Indian classical music and I have noticed there will be some feedback once in a while that I want to avoid completely.. 

 

Please kindly request to reply when you find time. I am in no hurry at all. My next gig will be sometime in Feb or March. 

 

Thanks again 

xytiz

 

 

12

Hello again xytiz,

 

Glad to hear your event went well.  Your volume adjustment made perfect sense -- I'm glad you made changes to recommendations to solve a problem!

 

Regarding a "back-to-back" setup:  I have no experience with such a configuration, but am thinking it may be an acoustic nightmare.  Depending on your space, I'm thinking there may be a lot of echo and cancellation.  The 180 degree dispersion is not cut-and-dried, and echoes from one end of the space may "muddy up" the sound pointed directly at the other end.

 

Again, if you have time to test, try a technique that others on the forum have used with great success:  Place the two L1's on either side and slightly in front of the performers, and turn them in slightly.  This way the performers can hear the the sound evenly (because of the 180 degree dispersion) without being directly in front of them.

 

Another concept for abating feedback (and very important when using systems with wide dispersion) is to minimize the number of microphones heard through any single L1.  The original L1 "ideal" concept was to have one performer per L1 (one vocalist and their instrument.)  In many situations this is not practical because of expense and space.  However, the L1's are versatile and powerful enough to overcome some of these hurdles.  However, when using two microphones through a system, the opportunity for feedback doesn't double, it increases roughly fourfold!  If using three mics, it is exponentially higher.  Also, having a mic heard through two systems is more prone to feedback.  Since you have three mics, your feedback threshold is much lower.

 

You might try plugging two of your mic's directly into channel 2 on each tower (with the appropriate mic presets.)  Yes, the vocalists will only be heard through "their" L1, but I think you may be surprised how much further you will be able to push those mic's before feedback.

 

You know your needs the most, and I think you're already getting a lot of great experience with these systems.  As I said before, don't be afraid to experiment!