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L1 MII resets (loses signal/sound/audio)

I have been battling this issue for several years, and have done everything I could do, but the issue pops up once in a while. At first, I thought I had a bad L1, so I sent it in, but that made no difference.

It only happens when:
- I am running on a 15 amp (not 20) circuit and if the voltage is not a perfect 120, so let's say 105ish.
-I combine a pair of F1 subs on the same circuit.
-Running near max capability on everything, including L1s (L1s flickering red on hard hits)

Anyhow, on to the issue--

A little background:
-I own a pair of the L1s (running T1 master analog output split)
-F1s are run directly off DJ mixer, not T1.

Problem:
-If I am playing near max (circuit shows 11-13 amps), the sound completely goes out on the loudest part of the song, but I still have power, and the F1 subs still pump out sound.

When looking at the L1 power stand, the power light stays on, but obviously, the signal goes out so no signal light. Within 5 seconds, sound comes back, but it SUPER EMBARRASSING, and I can't blame the power b/c everything else keeps going. It does some type of recycle.  It might only happen once a song, once every 30 minutes, or if the song has a lot of low end, it can happen several times a song.

If I turn down the F1 subs, the problem goes away completely. 

It's almost as if the L1 doesn't behave in low voltage and heavy load/near max capacity the circuit.

What are your thoughts?

 

 

Original Post

Hello, jaswrx.

You've done some great work documenting your situation. 

Your diagnosis is correct. When the line voltage the power available to the L1 Model II drops below the recommended operation range,

"if the voltage is not a perfect 120, so let's say 105ish."

the Power Stand will reset. 

"the sound completely goes out on the loudest part of the song, but I still have power, and the F1 subs still pump out sound.

When looking at the L1 power stand, the power light stays on, but obviously, the signal goes out so no signal light. Within 5 seconds, sound comes back, "

Your solutions are:

"turn down the F1 subs"

OR

Put the F1 Subwoofers on a different circuit.

Thanks for writing.

Bose Pro Community Admin



Edit: When the line voltage the power

but 105-110 is not below normal operating range according to the manual.

Does it have to be a perfect 120?

The F1 subs can operate at low voltage situations like this, and regardless, the F1 subs never reset, and always play sound.

Is this just a flaw in the L1? If anything, you would think the F1 subs would "cycle", not the L1s.

And when I say reset, I am just using that term generically, because all the lights stay on, but no audio comes through.

 

Hello, jaswrx,

I have amended my post above. 

"When the line voltage the power available to the L1 Model II drops below the recommended operation range, ..."

From your description, you are running near the limit the AC mains can supply, 

"I am running on a 15 amp (not 20) circuit and if the voltage is not a perfect 120, so let's say 105ish."

"If I am playing near max (circuit shows 11-13 amps)"

and you hit the L1 Model II with a transient peak,

""the sound completely goes out on the loudest part of the song,"

and there's not enough power to meet the momentary requirement. The L1 Model II resets.  The behavior you described (the sound stops and then resumes within seconds) indicates the system has reset itself. 

The L1 Model II and F1 Subwoofer are different devices so the behaviors are different. The difference does not evidence a flaw in one or the other. 

Bose Pro Community Admin

I am not so sure the L1 is necessarily hitting transient peaks bc it doesn’t cycle when I turn the subs down. 

Are you saying the L1 requires more power for a breif moment and shuts off bc it doesn’t have the power needs bc the F1 subs are using most if the power?

If so, I need to make sure I never ever see the red light flicker on the L1 so I have more headroom in case the L1 needs more power for a brief moment. 

I gotta say, generally the circuit will trip when pushing more power than available, not the speaker reset with no sound. It’s extremely embarrassing when it happens.  

Also, what is the lowest voltage I should operate the L1s and does one know the maximum amps a L1 with b1 uses?  

 

 I am going to guess 6 based on what’s happening  

 

Hello, jaswrx.

"the L1 requires more power for a breif moment and shuts off bc it doesn’t have the power needs"

Yes.

"generally the circuit will trip when pushing more power than available"

The circuit breaker may not trip immediately. Do a search for "how long does it take to trip a 15 amp breaker."

"Also, what is the lowest voltage I should operate the L1s and does one know the maximum amps a L1 with b1 uses?  "

The issue is not the voltage or the maximum amps. It's whether or not there is sufficient power available when you have a moment of higher than normal demand.

You have told us

"It only happens when:
- I am running on a 15 amp (not 20) circuit and if the voltage is not a perfect 120, so let's say 105ish.
-I combine a pair of F1 subs on the same circuit.
-Running near max capability on everything, including L1s (L1s flickering red on hard hits)"

To avoid the problem, run the F1 Subwoofers on a separate circuit or run the F1 Subwoofers at a lower volume, and ensure the L1 Model II Signal/Clip light is not flickering red. 

Bose Pro Community Admin

I understand what you are saying but I am shocked to hear that the L1 demands more power than a pair of F1 subs.  Even if I try, I can't get a pair of F1 subs to stop playing sound, even when clipping.

I wish the L1 didn't do this as F1s don't behave like this nor do any other speakers I have owned. 

Hello, jaswrx.

I'm sorry you are disappointed. Sooner or later, you will reach the limitations of any system. In this case, the system is the AC power circuit and all the equipment connected to it.  The L1 Model II will reset itself under conditions where the continued operation could lead to damage. We've already gone through the list of ways to avoid those conditions.

Bose Pro Community Admin

Yes, but the F1 doesn’t do this. It would make a lot more sense if the F1 subs did this since it draws a lot more power and is much more demanding. It’s very strange the L1 resets itself and the F1 doesn’t under a heavy load since a majority of the load is from the F1s.  I measured this from a kill o watt.

Yes, I have reached close to the maximum load from the circuit, but if I run F1 812s as tops this does not exist as a pair of 812s and F1subs are made to run on a 15amp circuit.   

Point being the L1 is not as efficient as the F1 even though it’s much less power.  Makes sense though since it is a much older product.

It’s a shame and I hope a new model iii comes out soon with more efficient power  😃

I will turn down my F1s to avoid the L1s resetting itself. 

Lastly, what is the optimal voltage I should look for from a circuit.  Is 105 too low?

So the ever occurring problem showed again last night.  The L1s will just reset (power light just stays on), but the L1 loses signal.  F1 subs keep playing regardless of volume or how hard I drive them, even while limiting.

The only solution was to turn down the F1 subs super low, or to turn the L1 lower, neither of which ideal. It was super embarrassing having people come over to tell me one of the speakers keeps cutting in and out.  Funny thing is I didn't even have the F1s running that hard. They were only pulling 3.5 amps.

I don't know what or why the L1 is so sensitive and inefficient to non-perfect power situations weather voltage or other things tied into the circuit.

I have come to realize they really need their own circuit with nothing plugged in and a perfect 115 volts. Anything below 110, and it's super risky. This has happened way too many times.

The majority of the power I was pulling was from the L1 (test via KillaWatt), but when you get closer to the 15amp maximum of the power circuit (other speakers plugged in) the L1 does not play well.

The F1 subs don't lose signal at all, even when you are drawing the maximum from the circuit, and I have tested this several times. The L1 will always cut out.

It's as the L1 requires a reserve and on the more demanding notes, it briefly realizes there is not sufficient power, so it just resets (loses signal for 3-4 seconds), even though it's completely unnecessary.  I am chucking it up to the amplifiers in the L1 not being as modern and efficient as what it is the newer F1.  I would like to feel like a firmware update could fix this, but I don't think that is something BOSE would consider at this point b/c the system is "protecting itself."  The L1 II is now 10 years old and the amp technology has come a long way, as seen in the F1 series of amplifiers. 

I hate to say this, but this might be the last year with my L1.  No other speakers do this, including other BOSE products.   It's too much stress in my business to continue like this.

 

 

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