I recently purchased a single BOSE L1 Model II PA system with the BOSE T4S mixer. I play the flute through a dynamic mic (Audix i5). I properly gain staged the T4S with my Audix i5 dynamic mic so that no clipping would occur. I then started exploring the Reverb options available on the T4S.
When using the T4S reverb, I'm observing a audible popping sound at the end of a note, particularly with the reverb mix is set above 50%. The popping sound appears to be more frequent with higher-pitched notes, and at higher SPL levels (although no clipping is occurring, even when playing these same notes as loud as possible). If the reverb is bypassed, this popping sound completely disappears -- even though the volume/gain levels remain the same.
I have downloaded and installed the latest firmware level for the T4S. I have tried to activate the compressor feature and equalizer to attenuate the higher frequencies, but the popping still occurs.
Any thoughts or suggestions to address this issue would be most welcome. Thank you in advance.
I recently purchased a single BOSE L1 Model II PA system with the BOSE T4S mixer.
Congratulations.
I play the flute through a dynamic mic (Audix i5). I properly gain staged the T4S with my Audix i5 dynamic mic so that no clipping would occur. I then started exploring the Reverb options available on the T4S.
When using the T4S reverb, I'm observing a audible popping sound at the end of a note, particularly with the reverb mix is set above 50%. The popping sound appears to be more frequent with higher-pitched notes, and at higher SPL levels (although no clipping is occurring, even when playing these same notes as loud as possible). If the reverb is bypassed, this popping sound completely disappears -- even though the volume/gain levels remain the same.
I have downloaded and installed the latest firmware level for the T4S. I have tried to activate the compressor feature and equalizer to attenuate the higher frequencies, but the popping still occurs.
Any thoughts or suggestions to address this issue would be most welcome. Thank you in advance.
I'm not sure what's happening with the reverb but try digital delay instead.
Thank you for your quick response. I muted the reverb and tried the Digital Delay as you suggested. With the parameter ranges you suggested, the audible pop at the end of the note was not present. However, to approximate the "Large" or "Cavern" reverb effects provided with the T4S, it is necessary to increase the Time, Mix, and Feedback parameters associated with the Delay effect. And, when I do that, the pop returns. I have not yet tried the Analog or Tape Delay options using the same settings. Here are the Digital Delay parameters I used to recreate the same problem I'm having with the Reverb:
The feedback parameter value, in this case, appears to introduce the popping problem for any value above 40%. Below that value, the popping sound is barely audible.
So both the reverb and delay introduce the problem. Oddly, as I indicated earlier, the problem only occurs on higher register notes on the flute. And this is true even if the SPL is the same for the higher notes and the lower notes (I measure the SPL using a Galaxy Audio SPL meter). And, as before, if I bypass both reverb and delay on the T4S, the same notes at the same volume level end cleanly -- no popping sounds.
I have not tried another mic just yet, although I do have other dynamic and condenser mics I can use. I've used this Audix i5 mic successfully with the flute now for many years with different PA systems, so I would be very surprised if this problem has anything to do with the mic itself. But it certainly can't hurt to try other mics in my collection.
Also, just a follow-up to my last post. I just tested both the Analog and Tape delay options on the T4S. The Tape Delay results were more-or-less identical to the Digital Delay (popping sound occurs once the Feedback parameter exceeds 30% or so). The Analog Delay was better, but I could still produce the popping problem when the Feedback was set at 70% or higher.
An update regarding this issue using different vocal mics. First, I ran the same test with the T4S reverb using the Audix i5 as before. But this time I disconnected the T4S from the BOSE L1 Model II and used my studio headphones connected to the headphone port on the T4S. The same popping sound was heard as reported earlier. So this test eliminates the L1 Model II PA as the potential problem source.
I then ran the exact same test using 2 different Shure dynamic mics: SM Beta 58A and SM57. Before running each test, I made sure that I selected these mics from the ToneMatch menu, since these profiles were already available in the preset list. In both tests, the popping sound was also audible. Interestingly, the issue was not as pronounced with the SM57 compared with the SM Beta 58A or the Audix i5 -- but was still audible.
So 3 different dynamic mics have now been tested, and all 3 experience the same problem with the reverb popping with upper register notes (G5 and above) on the flute at moderate to high SPL levels. The L1 Model II PA has been removed from the signal chain. So this must be an issue with the T4S mixer.
Any other suggestions from this community would be most welcome. If no solution is found, I'll have to consider other options for introducing clean reverb and delay into the signal chain (e.g., using the BOSS VE-20 or similar vocal effects box). This would be a shame given the price and expectations I had when purchasing this mixer with the L1 Model II PA. Reverb and Delay are pretty standard effects when playing the flute in a live performance. These effect should work as advertised (IMHO).
Thank you for your response. There are at least 3 pieces of evidence that do not support your line of reasoning for the root cause of this problem.
The popping sound is only heard at the end of a note, when I'm no longer supplying any breath to the flute (e.g., at the end of a musical phrase).
The popping sound is only heard with notes are played at G5 or above on the octave scale. This suggest that the frequency of the note(s) has something to do with the problem when reverb/delay is being used.
I recently added a BOSS VE-20 Vocal Effects box to the audio chain (mic --> VE-20 --> T4S -> L2 Model II). I then used the Reverb settings on the VE-20 and ran the same tests with all 3 dynamic mics in my collection (Audix i5, Shure SM-57, Shure SM-58 Beta). No popping noise was detected with this configuration.
My guess here is that there is some problem with the firmware and/or circuitry in the T4S associated with the Reverb/Delay effects. I was hoping there might be some parameter configuration associated with the channel that could be used to work around the problem, without sacrificing the use of reverb or delay provided by the mixer, but I have not found any.
Thank you for your response. I contacted BOSE PRO Technical Support last Friday, and then followed-up this morning with all my test results that I have already documented on this forum. They believe the problem is a faulty unit, and sent me a return authorization label to return the T4S back to BOSE. A brand new T4S will be shipped to me once the return of the current unit is confirmed. If this problem still occurs with the new unit, I will make a recording of the sound being heard and post it to this forum as you requested.
Are you sure that you are not simply hearing a sound that is really there? When you are playing a flute there could be either a breath or key clatter sound at the start of the note that doesn't register until it is delayed. It could be worth making a recording of some playing through the T4S (clean) and listening to and analysing it on a computer. Then add some delay there to see if a low-level 'transient' becomes noticeable once delayed.