ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Wireless and Communications => Topic started by: TJ (Tom) Cornish on July 08, 2018, 07:20:59 AM

Title: Lectrosonics M2 Duet sound quality!?
Post by: TJ (Tom) Cornish on July 08, 2018, 07:20:59 AM
I finally received the Lectrosonics M2 Duet IEM system I ordered like 9 weeks ago.  I’ve used Sennheiser IEM G3s and Shure PSM900s for many years; this is my first Lectrosonics product of any kind.

The features are cool, but the sound quality is....significantly worse than I expected.  There are two issues:

- The headphone jack on the transmitter has an unbelievable amount of hiss no matter where the volume control is set

- sound through the receiver has a gated hiss/buzz sound that is really noticeable with a low input level to the transmitter and a high pack volume.  This noise improves with sending the transmitter a very hot signal and turning the receiver down.

Are these characteristic of the M2 system?  I’ll likely never use the on-transmitter headphone jack and if I slam the transmitter with a hot signal and keep the receiver pack volume low it does sound better than the lesser IEM systems I’m familiar with, but it’s not the “24 bit digital audio/digital RF” experience I was expecting for the $$$$.

I’m going to try to contact Lectrosonics support this week, but thought I’d solicit other user experiences.

Thanks
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: TJ (Tom) Cornish on July 09, 2018, 04:01:44 PM
I contacted Lectrosonics support and they confirmed the following:

- yes, the headphone jack in the transmitter is noisy.  I think this is lame on a very expensive piece of premium gear, but it's not in the main signal flow, so whatever, I guess.

- They did confirm the existence of quantization noise which is quite audible with poor gain structure and high pack volume.  My experience using the unit this weekend is that if you hit the transmitter pretty hard and turn the pack volume down (which really is how IEMs should be run so the hearing protection limiters function) it's not hugely objectionable.  I was told that this may improve in a forthcoming firmware update.

- My last gripe is the lack of a NiMh battery profile for the battery meter.  The choices are lithium and alkaline, but a fully-charged set of Eneloops show at about 60% capacity on the pack meter.  Hopefully they will add this in the future, as it's frustrating to have to tell the talent "Yes, I know the battery meter shows just over half capacity; I just put new batteries in them and it's the meter that's wrong".
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: Andrew Broughton on July 09, 2018, 04:08:05 PM
They absolutely need to bring out a lithium-ion/poly battery pack and charging system for the Duet.
If they want to compete with the PSM1000 they will need to include all the best features of the competition.
I can say, though, that when hit with enough signal, and with a strong RF signal at the receiver, these do sound better than the rest. I'm keeping watch to see if they keep making improvements as I think it may still be a little early yet to jump into these.
I've asked for the following improvements:
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: TJ (Tom) Cornish on July 09, 2018, 04:42:31 PM
They absolutely need to bring out a lithium-ion/poly battery pack and charging system for the Duet.
If they want to compete with the PSM1000 they will need to include all the best features of the competition.
I can say, though, that when hit with enough signal, and with a strong RF signal at the receiver, these do sound better than the rest. I'm keeping watch to see if they keep making improvements as I think it may still be a little early yet to jump into these.
I've asked for the following improvements:
  • "Smart" Rechargable battery pack and charging system like the PSM1000
  • Indication when in IR range when syncing like the PSM1000
  • Negative Gain values in addition to the positive values available currently in the limiter section
  • Improvement in sound quality when on RF fringes
I agree that the limiter is counter-intuitive. 

I probably should have gotten a demo before jumping in sight-unseen, but based on the Lectrosonics reputation, I took a risk. 

My first reaction is that the M2 is a mashup of really cool plus a bit of pretty lame.  I've no doubt that the RF technology is first class, but the noisy $0.03 headphone amplifier in the transmitter leaves a bad taste, and I believe the battery door of the receiver is poorly designed compared to Shure and Sennheiser.  On those, it takes a very precise oblique hit to open the battery door compartment, and even then, that just opens the door - the batteries are still (probably) intact.  On the Lectrosonics, the battery door pushes down and is part of the electrical contact of the cells.  If you wear it on the left side of your body, a downward arm movement can catch the battery door, causing it to open and the batteries to fall out.  This can also happen when gripping the pack body trying to hook the clip on your pocket or belt.

I'm satisfied enough to keep the thing I think, but this is definitely 3 stars out of 5.  You can do better, Lectrosonics!
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: Tim Hite on July 09, 2018, 07:21:41 PM
If you need a demo of anything from Lectrosonics in the future, give me a shout.

I probably should have gotten a demo before jumping in sight-unseen, but based on the Lectrosonics reputation, I took a risk. 

Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: Andrew Broughton on July 09, 2018, 07:52:45 PM
I agree that the limiter is counter-intuitive. 

I probably should have gotten a demo before jumping in sight-unseen, but based on the Lectrosonics reputation, I took a risk. 

My first reaction is that the M2 is a mashup of really cool plus a bit of pretty lame.  I've no doubt that the RF technology is first class, but the noisy $0.03 headphone amplifier in the transmitter leaves a bad taste, and I believe the battery door of the receiver is poorly designed compared to Shure and Sennheiser.  On those, it takes a very precise oblique hit to open the battery door compartment, and even then, that just opens the door - the batteries are still (probably) intact.  On the Lectrosonics, the battery door pushes down and is part of the electrical contact of the cells.  If you wear it on the left side of your body, a downward arm movement can catch the battery door, causing it to open and the batteries to fall out.  This can also happen when gripping the pack body trying to hook the clip on your pocket or belt.

I'm satisfied enough to keep the thing I think, but this is definitely 3 stars out of 5.  You can do better, Lectrosonics!

I didn't find the limiter necessarily counter-intuitive, but because it has a continuous gain control in there, I saw the benefit of being able to set a negative gain so that a user could simply crank the volume on the top up full, and use the limiter gain to set their desired level. Similar idea to the PSM1000 "max volume" setting, but much more useful, since you'd have the full range of control with the volume knob.
I doubt I would ever use the actual limiter function in the pack. I don't think the Shure even has one anymore!?

That's a real problem with the battery compartment, I didn't notice that. Our players have holsters for their packs so it wouldn't be an issue, but certainly for players clipping them to their belt or pocket, that should be rectified.
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: Henry Cohen on July 09, 2018, 09:11:40 PM
. . . I've asked for the following improvements:
    . . .
       
    • Improvement in sound quality when on RF fringes
Anytime a receiver is at the edge of the RF coverage area, any or all of the performance parameters will suffer, whether analog or digital. That's why it's a fringe area. If you need proper receiver performance at a given location, then you need to address your transmitter and antenna deployment.
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: TJ (Tom) Cornish on July 10, 2018, 08:51:20 AM
Anytime a receiver is at the edge of the RF coverage area, any or all of the performance parameters will suffer, whether analog or digital. That's why it's a fringe area. If you need proper receiver performance at a given location, then you need to address your transmitter and antenna deployment.
While agreeing completely with your statement above and not knowing what Andrew is referring to specifically, in the firmware notes for the Duet they have called out better squelch settings as an improvement that happened somewhere along the way, which is a useful feature when the talent walks to the restroom and is saved from ear-splitting static.

Perhaps this was an issue when Andrew used the Duet last.
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: Andrew Broughton on July 10, 2018, 10:03:27 AM
Anytime a receiver is at the edge of the RF coverage area, any or all of the performance parameters will suffer, whether analog or digital. That's why it's a fringe area. If you need proper receiver performance at a given location, then you need to address your transmitter and antenna deployment.
Of course, but when musicians walk off the stage and out of the coverage area, the system needs to mute comfortably, not hit you with loud digital noises. As TJ says, this may have been addressed since when I tested the system. The way the sound goes garbled and digital as you reach the fringes is very unnerving.

Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: TJ (Tom) Cornish on July 10, 2018, 10:36:27 AM
There have actually been two fixes related to squelch - December 2017 and then January 2018:

WD Firmware Update v25Jan2018
M2R v1.10 (SUPER)/v1.11 (FPGA)
Added, frequency, numerical volume setting and mix mode indicators to the main display page.
Added SmartTune feature.
Further improvements to squelch operation to prevent loud drop-outs.
Doubled the scanning speed.

WD Firmware Update v13Dec2017
M2R v1.03 (SUPER)/v1.06 (FPGA)
Apply log taper to volume control for finer resolution at low levels.
Improved squelch operation to prevent loud drop-outs.


https://www.lectrosonics.com/Support/M2-Duet-System/m2r-firmware-revision-history.html
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: Karl Winkler on July 10, 2018, 01:41:19 PM
There have actually been two fixes related to squelch - December 2017 and then January 2018:

WD Firmware Update v25Jan2018
M2R v1.10 (SUPER)/v1.11 (FPGA)
Added, frequency, numerical volume setting and mix mode indicators to the main display page.
Added SmartTune feature.
Further improvements to squelch operation to prevent loud drop-outs.
Doubled the scanning speed.

WD Firmware Update v13Dec2017
M2R v1.03 (SUPER)/v1.06 (FPGA)
Apply log taper to volume control for finer resolution at low levels.
Improved squelch operation to prevent loud drop-outs.


https://www.lectrosonics.com/Support/M2-Duet-System/m2r-firmware-revision-history.html

Hi Tom,

We also have some additional updates that are still in beta form if you would like to try it out on your units. If so, please PM me with your email address.

We do have some scheduled updates in the works beyond those, as well. Included are the transmitter headphone jack. Believe it or not, it is not a cheap part, but we are having to make some tradeoffs in the firmware domain to get the headphone jack quiet. We will get there.

We also have on the list several of Andrew's suggestions, specifically the "IR in range" feature and the negative limiter gain values. The addition of smart recharging packs will need to wait for the next generation.

I do think the audio performance on the fringes is much better as of v1.11 - when the unit squelches it is quite gentle. Agreed that versions earlier than that could sound harsh on dropouts.
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: TJ (Tom) Cornish on July 10, 2018, 02:29:30 PM
Hi Tom,

We also have some additional updates that are still in beta form if you would like to try it out on your units. If so, please PM me with your email address.

We do have some scheduled updates in the works beyond those, as well. Included are the transmitter headphone jack. Believe it or not, it is not a cheap part, but we are having to make some tradeoffs in the firmware domain to get the headphone jack quiet. We will get there.

We also have on the list several of Andrew's suggestions, specifically the "IR in range" feature and the negative limiter gain values. The addition of smart recharging packs will need to wait for the next generation.

I do think the audio performance on the fringes is much better as of v1.11 - when the unit squelches it is quite gentle. Agreed that versions earlier than that could sound harsh on dropouts.
Thanks for reaching out, Karl.  PM sent.
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: Andrew Broughton on July 10, 2018, 05:39:05 PM
Hi Tom,

We also have some additional updates that are still in beta form if you would like to try it out on your units. If so, please PM me with your email address.

We do have some scheduled updates in the works beyond those, as well. Included are the transmitter headphone jack. Believe it or not, it is not a cheap part, but we are having to make some tradeoffs in the firmware domain to get the headphone jack quiet. We will get there.

We also have on the list several of Andrew's suggestions, specifically the "IR in range" feature and the negative limiter gain values. The addition of smart recharging packs will need to wait for the next generation.

I do think the audio performance on the fringes is much better as of v1.11 - when the unit squelches it is quite gentle. Agreed that versions earlier than that could sound harsh on dropouts.
Thank you, Karl. I'm very excited about this product. The tuning range is wider than any other IEM I've seen and the sound quality is superb. The numeric readout of the volume setting is very handy, and I know these other planned features will make it the "PSM1000 killer" I know it can be!
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: TJ (Tom) Cornish on August 06, 2018, 01:55:34 PM
An update - I'm sending it back.  The RF performance is 6 stars out of 5.  It is really amazing, even on low power.  For shows with tight RF requirements this thing would be fantastic.  Unfortunately the audio quality annoys me.  I've probably got the yips about this and I suspect others may be fine with it - in a live setting with stage volume the artifacts that bother me aren't audible, but I've done enough work doing head-to-head tests and analysis that I'm going to always hear what I hear.

Thanks to Karl and team for letting me try the beta firmware.  Sign me up for Duet version 2 at some point in the future.
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: Andrew Broughton on August 06, 2018, 07:38:25 PM
Hopefully the v2 comes soon, as I really want to get a set of these, once they work out the above issues and missing features.
Title: Lectrosonics M2 Duet sound quality!?
Post by: Andrew Broughton on November 22, 2018, 04:53:46 PM
V2 software is out with what they’re calling High Resolution Audio.

Anyone tried it?


Sent from my iPhone using Tapatalk Pro
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: Tim Hite on November 23, 2018, 12:34:40 PM
I'll probably get to it this weekend. . .

Currently playing with things to improve Duet range for some location sound clients who are used to 250mW IFB systems.

V2 software is out with what they’re calling High Resolution Audio.

Anyone tried it?


Sent from my iPhone using Tapatalk Pro
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: TJ (Tom) Cornish on November 23, 2018, 07:19:29 PM
V2 software is out with what they’re calling High Resolution Audio.

Anyone tried it?


Sent from my iPhone using Tapatalk Pro
Looking at the feature list, it appears to combine some of the stuff I tested in July plus a few new things including at least one suggestion I made (changing the meter scale to a 0DBFS-type model).  I'm curious to hear what you think.  To me, the new codec didn't fix the major complaint I had - a gated hiss (quantizing noise) underneath the audio.  I would love to hear that this is fixed, but I have a feeling I've already heard the "high resolution audio".
Title: Re: Lectrosonics M2 Duet sound quality!?
Post by: Andrew Broughton on November 24, 2018, 12:50:16 PM
After decades of using rechargeables in my Sennheisers and now the Li-Ion rechargeables for the past several years with the PSM1000, the lack of a Li-Ion pack for the Duet makes this a non-starter for me. "Once you've tried it, you just can't go back"