New MECA system - unbelievable audio

Status
Not open for further replies.

kg9qm

Member
Joined
May 22, 2008
Messages
65
After listening for a day I'm stunned by the distorted audio. It's incredible to think these $5000 Motorola radios sound so much worse than my $99 Motorola RAZR cellphone. Evidently their audio is way, way over compressed. It sounds like some really awful YouTube video streams, doesn't it?

It was just a couple months ago I saw a news story touting the digital clarity that was going to replace the old, scratchy, noisy analog signals.

I can't fault IFD for bucking the system on this. I AM surprised every agency isn't raising similar concerns.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
65,126
Location
Virginia
kg9qm said:
After listening for a day I'm stunned by the distorted audio. It's incredible to think these $5000 Motorola radios sound so much worse than my $99 Motorola RAZR cellphone. Evidently their audio is way, way over compressed. It sounds like some really awful YouTube video streams, doesn't it?

It was just a couple months ago I saw a news story touting the digital clarity that was going to replace the old, scratchy, noisy analog signals.

I can't fault IFD for bucking the system on this. I AM surprised every agency isn't raising similar concerns.

Keep in mind what you are hearing on the scanner is diffrent than what they hear on there XTS5000 or the mobles the scanners have a hard time decoding that type of digital vs say Safe T where it is just Digital Voice. You need to have a real good signal for the scanner to decode it. If using a 996T or a 396T make sure you have the latest Firmware upgrade it has sevral settings that are new in it to help clear it up but you will get some messed up Audio from time to time thats just digital and yes the PD should worry about the noise as well when using sirens or driving with the window down and having wind noise.
 
Last edited:

GTO_04

Member
Premium Subscriber
Joined
Mar 10, 2004
Messages
1,785
Location
Noblesville, IN
w8fcc said:
Keep in mind what you are hearing on the scanner is diffrent than what they hear on there XTS5000 or the mobles the scanners have a hard time decoding that type of digital vs say Safe T where it is just Digital Voice. You need to have a real good signal for the scanner to decode it. If using a 996T or a 396T make sure you have the latest Firmware upgrade it has sevral settings that are new in it to help clear it up but you will get some messed up Audio from time to time thats just digital and yes the PD should worry about the noise as well when using sirens or driving with the window down and having wind noise.
The 396 actually does better on the new MECA P25 compared to SAFE-T. The only remaining issue on the 396 is the motorboating on SAFE-T. It is improved but is still there sometimes. I have had no motorboating on the new MECA system. I suspect the 396 has some issue deciding whether is is picking up an analog or digital signal at the beginning of the transmission.

The PSR-500 has been just about flawless on both systems.

There are some times when I cannot hear the firefighter's handhelds at a fireground with various equipment running in the background, but nobody else can either. I noticed that the digital systems have a major issue with sirens in the background too. I guess they'll have to turn off the sirens before they talk on the radio. Maybe they can design a mic that can handle that backround noise. You would think they would have worked that issue out before marketing these systems to public safety users.

GTO_04
 

kg9qm

Member
Joined
May 22, 2008
Messages
65
Seems odd to have difficulty decoding as I'd think there would be very good error detection/correction in the digital packets. But if the '5000s decode it well, then that seems to mitigate the noise 'problem.' With clean audio, how is siren or windnoise any more of a factor simply because the radio transmission was digital?

If I am to believe Karen Hensel's WISHTV report, they have audio that's about as lousy as what I hear on my scanner.

I still go back to the digital cellphone analogy, which is exceptionally clean and clear - and cheap -yet for some reason those expensive radios are not from all indications.

It appears I do have the latest firmware, minus the 'esn' update which appears to be the sole change to the latest-1 version that's in the radio.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
65,126
Location
Virginia
The version you should have is
396T 2.00.07

996T 2.00.06

It does make a big diffrence I have no issues with MECA Digital or Safe T however I did not see any change to EDACS.
When you get this firmware the settings are hidden off the main menue you need to unlock them by holding the hold botton down while turning on the scanner to make the changes.
Cell phones keep in mind there are many more cell sites than what MECA has and it is a little diffrent but it is clear I will give you that.
 

jerk

Active Member
Joined
Sep 5, 2003
Messages
2,446
Location
jerkville
kg9qm said:
Seems odd to have difficulty decoding as I'd think there would be very good error detection/correction in the digital packets. But if the '5000s decode it well, then that seems to mitigate the noise 'problem.' With clean audio, how is siren or windnoise any more of a factor simply because the radio transmission was digital?

If I am to believe Karen Hensel's WISHTV report, they have audio that's about as lousy as what I hear on my scanner.

I still go back to the digital cellphone analogy, which is exceptionally clean and clear - and cheap -yet for some reason those expensive radios are not from all indications.

It appears I do have the latest firmware, minus the 'esn' update which appears to be the sole change to the latest-1 version that's in the radio.
Cell phones are not equal to digital radio technology. It's not apple to apples comparison.

Cell phones are generally CDMA or TDMA, Nextel is IDEN, so all have a different Vocoder scheme. That's why cell phones sound better than digital radios. Short non-technical explanation.
 

kg9qm

Member
Joined
May 22, 2008
Messages
65
newsalan said:
Cell phones are not equal to digital radio technology. It's not apple to apples comparison.

Cell phones are generally CDMA or TDMA, Nextel is IDEN, so all have a different Vocoder scheme. That's why cell phones sound better than digital radios. Short non-technical explanation.
I have no idea what point it is you are trying to make. In all cases it a plastic box with electronics inside converting voice to data and sending it somewhere. Comparing one box that does it well and cheaply to another that (seems to) do it poorly at many times the cost - why not? We compare digital to analog radios and those aren't both apples, either.

For that kind of money there should be the best CODEC possible, be that iDEN (these are Motorola radios, after all), IS-136 or EFR - or something else.

But that may simply be lowest common denominator coming into play with all P25 gear relying on DVSI's IMBE VOCODER. Of course, that now has been one-upped by AMBE.

The new system is already on it's way to obsolesence and it's not even deployed yet. Ain't that swell?
 

DiGiTaLD

Member
Joined
Aug 10, 2005
Messages
692
The biggest problem we (as scanner listeners) are going to experience with distorted audio on this system results from the fact that's it's LSM P25 simulcast. Yes, it is P25 digital voice, however a slightly different flavor than that used on SAFE-T in it's several simulcast configurations. The short story is that the scanners cannot deal with receiving LSM P25 in simulcast near as well as the real subscriber radios can.

Since the system hasn't been used operationally yet, I haven't heard that much traffic on it, however what little I have heard (that wasn't killed by simulcast multipath blowing out the receive on my 96/2096) has sounded comparable to SAFE-T. SAFE-T sounds great, even on a 2096, and when you hear it on a subscriber radio, to me it sounds comparable to an iDEN device, i.e. Nextel, if not better.
 

kg9qm

Member
Joined
May 22, 2008
Messages
65
Well, I do think it's sounding a little better now that I have flashed in V2.00.07. But those bus (er, 'coach') drivers haven't got much to say.

thanks w8fcc.
 

jerk

Active Member
Joined
Sep 5, 2003
Messages
2,446
Location
jerkville
kg9qm said:
I have no idea what point it is you are trying to make.
I made it simple, perhaps too simple. They are all different types of digital encoding. And they all have different audio compression schemes.
kg9qm said:
The new system is already on it's way to obsolesence and it's not even deployed yet. Ain't that swell?
Obsolescence? How so, because you can't monitor it on a scanner. Because you don't like it? Because you believe the news hype and the firefighters scare tactics?

It's a brand new system, probably still in testing, I would say it could last as long as or longer that the old system.
 

kg9qm

Member
Joined
May 22, 2008
Messages
65
newsalan said:
I made it simple, perhaps too simple. They are all different types of digital encoding. And they all have different audio compression schemes.

Obsolescence? How so, because you can't monitor it on a scanner. Because you don't like it? Because you believe the news hype and the firefighters scare tactics?

It's a brand new system, probably still in testing, I would say it could last as long as or longer that the old system.
Because the scheme has been superceded with a newer, and evidently improved variant. Basic definition of 'obsolete' - newer and better comes along to replace older technology.
 

Viper43

Member
Joined
Jul 23, 2005
Messages
3,307
The new system is coming through loud and clear here at home....and I'm well outside the Marion County line.
 

kg9qm

Member
Joined
May 22, 2008
Messages
65
Viper43 said:
The new system is coming through loud and clear here at home....and I'm well outside the Marion County line.
Half the test chatter is crystal-clear, the other is good - better than what I'd heard earlier in the day. I surmise the guy counting 12345, 54321 is probably talking a bit wierdly, only exaggerating the slightly-off sound and he's perhaps on a handheld. The other voice acknowledging 'OK' must be a base unit, because he's louder and the audio seems to have a much wider spectrum.

And the TGIDs are below 10012, which is the lowest number shown on the current database listing.
 

Viper43

Member
Joined
Jul 23, 2005
Messages
3,307
motorboating is simply hearing the data on the data channel on Mot type II (and 1) systems, you won't hear the same on P25 as it's a different sound
 

Viper43

Member
Joined
Jul 23, 2005
Messages
3,307
Actually I have noticed when it's overcast it sounds better, nice clear days it's bad and windy days it is worse.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
65,126
Location
Virginia
kg9qm said:
Half the test chatter is crystal-clear, the other is good - better than what I'd heard earlier in the day. I surmise the guy counting 12345, 54321 is probably talking a bit wierdly, only exaggerating the slightly-off sound and he's perhaps on a handheld. The other voice acknowledging 'OK' must be a base unit, because he's louder and the audio seems to have a much wider spectrum.

And the TGIDs are below 10012, which is the lowest number shown on the current database listing.

Thats Because the DB may be wrong Motorola and MECA have been testing on 10001 through 10012 and that was listed in the DB as Tac 1-12 but now they start at 10012 in the DB MECA has been calling 10001 S1 T1 so who knows I would hold off labeling anything till they cut over some of the Fire TG listed in the DB are wrong as well. But in the same breath MECA/Motorola called 10012 S1 T6 last night so I dont think that they even know what is going on. Alot of the IMPD radios this week have the wrong Unit Radio ID showing the officers ID number and they have been asking the officers that are wrong ID to take the radios back to MECA sounds like they need more time and not to rush cutover.
If Scott Newman has his way they will wait and maybe start over with a new system hopefuly this time it would be like Safe T. All they have to is go back on Motorola with some good attorneys or a lot of bad press witch they are getting now.
 

ten78

Member
Joined
Feb 16, 2008
Messages
81
On SAFE-T, i'm frequently hearing white noise? for a sec then the audio kicks in.
 

kg9qm

Member
Joined
May 22, 2008
Messages
65
ten78 said:
On SAFE-T, i'm frequently hearing white noise? for a sec then the audio kicks in.
Not for me, but occasionally I get a short brrapp from a control channel coming through (which I thought was something fixed in one of the earlier firmware updates). It's like the squelch doesn't lock fast enough after a voice xmit ends and the next channel scanned happens have the control signal on it.
 
Status
Not open for further replies.
Top