Nickie
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Dec 19, 2019

L1 Classic Model I - no bass from B1 bass modules

Hi 

Ive just purchased an l1 classic model 1 system and connected the 2 b1 subs only to find that theres no bass coming thru. I removed the speaker towers from the base unit and just connected the subs to find  that if i increased the volume to a very high setting there was some but little signal coming thru. Could this be a problem with a dry joint in side the unit? or a failure from the amp? Help please 

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ST - Pro
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May 11, 2020

Re: L1 Classic Model I - no bass from B1 bass modules

Hi Nick123,

Welcome to the Bose Portable PA Community.

I'm sorry you are not getting any bass from the B1 bass modules.

Are you connecting things like this?

Do you have the original blue bass module cables?

In case you're not familiar with Speakon connectors, you have to insert them and then turn clockwise until the CLICK and lock into place.

Please check the bass module cables to make sure all four wires are connected inside the NL4 connections.  For details see: Check the cables

Here's some more information you may need.

L1® Classic Owners Guide

L1® Model I System Quick Set-up Guide

ST

xytiz
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Oct 19, 2019

Re: L1 Classic Model I - no bass from B1 bass modules

If you have tried the above and still dont get it working , First suspect the cable and  Remember to ALWAYS use amp 3 out when tower speaker are connected to the power stand .. If not bad things can happen ... Good Luck ..

 

Nickie
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Re: L1 Classic Model I - no bass from B1 bass modules

Hi 

Thanks for the response 

Ive just tried the system again after leaving overnight and there is some sound coming thru but its  like coming in and out with slightly distorted signal. Hoping its not the amp that drives the sub with the problem.

Do you think it may be a dry joint on the connector inside the unit? 

Ive got a number of correct speakon leads and ive tried them all with the same results 

Hoping this can be sorted and its not a catastrophic failure of the unit 

Nickie
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Dec 19, 2019

Re: L1 Classic Model I - no bass from B1 bass modules

Oh forgot to add that on start up the speakers emit a slight hissing crackling sound that disappears after a few seconds.

Thanks in advance for any help with these problems 

xytiz
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Re: L1 Classic Model I - no bass from B1 bass modules

Dry joints are rare and I feel the only solid way to figure that out is if you have another l1 system where you can selectively check and eliminate each component ... else with some courage one has to open the power stand and check the circuitry for soldering issues etc , you can also check connectivity using a multimeter...

Have you connected remote ? If so keep all the controls to ‘0’ and power on .. ensure you connect to a proper 110v power source and not from a ups or generator anything like that .. use above avg power strip with surge protection that tells if there is faulty wiring in the building .. 

with that said increase the volume on the power stand to ‘2’ and not more , then increase the gain slowly followed by low (to check the bass)and master vol on the remote slowly .. Power on l1 after input signal is powered on if it’s line level .. ensure every volume controls , gain controls of all the remaining channels is at ‘0’ on both power stand and remote ..

As I had suggested earlier it’s a 10 -15 yr old system , cables should be your first level of suspicion ... ( my experience feel free to ignore it : my remote cable -7 dim connector had gone bad for no particular reason ... maybe some moisture gets into them and corrode them ... I opened up the remote to see if any chip was burned or anything smells burnt inside could not sense anything like that .. ordered a new remote cable from amazon , patiently waited ?? till it arrived and tested the remote with new cable and to my relief it worked like a charm .. I really thanked god ??.. )

these systems are robust the amp is very powerful and have multiple fault tolerances built into them ..So hopefully it’s not anything too bad .. keep at it .. good luck .. 

 

xytiz
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Re: L1 Classic Model I - no bass from B1 bass modules

Slight hissing sound at startup is normal .. that’s okay .. don’t worry too much about it .. 

Nickie
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Re: L1 Classic Model I - no bass from B1 bass modules

Thanks so much I'll try what you said and hopefully it will get resolved.

I'll let you know how i get on 

Thanks once again

ST - Pro
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Re: L1 Classic Model I - no bass from B1 bass modules

Hi Nick,

Nick123 posted:

Hi 

Ive just purchased an l1 classic model 1 system and connected the 2 b1 subs

Do you have the option to return the unit?

only to find that theres no bass coming thru. I removed the speaker towers from the base unit and just connected the subs to find  that if i increased the volume to a very high setting there was some but little signal coming thru. Could this be a problem with a dry joint in side the unit? or a failure from the amp? Help please 

You've mentioned the "dry joint" possibility several times.   This seems unlikely.  Please note: There are no user serviceable components inside the unit. 

Nick123 posted:

Hi 

Thanks for the response 

Ive just tried the system again after leaving overnight and there is some sound coming thru but its  like coming in and out with slightly distorted signal. Hoping its not the amp that drives the sub with the problem.

Do you think it may be a dry joint on the connector inside the unit? 

Ive got a number of correct speakon leads and ive tried them all with the same results 

Okay - that probably eliminates an issue with the cable from the Power Stand to the B1. 

Hoping this can be sorted and its not a catastrophic failure of the unit 

Have you tried connecting just one B1?

Nick123 posted:

Oh forgot to add that on start up the speakers emit a slight hissing crackling sound that disappears after a few seconds.

That's not unusual.



Thanks in advance for any help with these problems 

Other notes:

If the Cylindrical Radiator® (tower) is working correctly, the problem is NOT the R1 Remote, or R1 Remote cable.

Troubleshooting:

Testing Amp 1

  1. Remove the Cylindrical Radiator® and R1 Remote
  2. A: Connect a music source to All Amps IN (recorded music is good) 
  3. B: Connect one B1 to the Power Stand Amp 1 OUT
  4. Do you hear sound through the B1?
  5. B Connect the other B1 to the Power Stand Amp 1 OUT
  6. Do you hear sound through the B1?

If you hear sound in all these scenarios, the Amp 1 and the B1s and the cables are fine.

Testing Amp 2

  1. Remove the Cylindrical Radiator® and R1 Remote
  2. A Connect a music source to All Amps IN (recorded music is good) 
  3. C Connect one B1 to the Power Stand Amp 2 OUT
  4. Do you hear sound through the B1?
  5. C Connect the other B1 to the Power Stand Amp 2 OUT
  6. Do you hear sound through the B1?


If you hear sound in all these scenarios, the Amp 2 and the B1s and the cables are fine.

Testing Amp 3 

  1. Remove the Cylindrical Radiator® and R1 Remote
  2. A Connect a music source to All Amps IN (recorded music is good) 
  3. D Connect one B1 to the Power Stand B1 Bass Module Amp 3 OUT
  4. Do you hear sound through the B1?
  5. D Connect the other B1 to the Power Stand B1 Bass Module Amp 3 OUT
  6. Do you hear sound through the B1?

If there is no sound when you are connected to D there is a problem with Amp 3.  

Nick123 posted:

Hi 

Ive just purchased an l1 classic model 1 system and connected the 2 b1 subs

Do you have the option to return the unit?

ST

Nickie
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Dec 19, 2019

Re: L1 Classic Model I - no bass from B1 bass modules

Hi all

Sorry for the delay in replying.

Update

I checked each output from the three separate amps to find that there was no signal coming from the bass amp. 

 

I took the base to my local amp repair man and he said that having the very awkward time consuming task of getting to and accessing the bass amp found that there were dry joints. He saw to these and reconnected the b1 sub it worked perfectly. He charged me £75 which i was very pleased with considering the time he had to spend getting into the base unit.

So to summarise the problem was dry joints.

Once again thanks to all