Poor HD sound quality with VU+ Duo2 fitted with Terrestrial T2 tuner

[B&W]

I have noticed there is an existing issue with poor sound quality with my VU+ Duo2 (Genuine) receiver.
Installed tuners are (A) DVB S2 fixed dish 0.8m, (B) DVB S2 1.2m Diseqc and (C) Terrestrial DVB-T2/T/C.
Latest releases of Apollo and Hades exhibited the same audio issue.
I have always performed clean installations no restores and no extra plugins that could potentially interfere.

The problem experienced is the sound quality significantly drops when receiving HD Terrestrial; however satellite HD feeds are not affected.
I will try to describe the difference experienced when using Terrestrial DVB-T2 tuner:-
1) Audio level is attenuated by about 40% when compared like for like on satellite channels
2) Sound is highly compressed equivalent to mp3 audio sounding muffled with limited dynamic range.
3) Every 30-50 seconds there is a low level audible glitch similar to an interruption to the audio D/A convertor data stream.
Other configurable audio formats In VU+ AV audio menus do not change the problem this exist with other selected audio formats, I mainly use PCM audio stream because the Linn Klimax DSM demands it.
Terrestrial DVB signal reception is excellent and is buffered to all other devices .My other receivers for example Panasonic DMR BWT800 connected to Arcam 600 processor has excellent HD Terrestrial audio when compared.
The VU+ receiver HDMI output is connected to the following high end 7.2 surround audio devices but mainly used in 2 channel digital audio mode; Arcam, Linn Klimax DSM, Krell amps in an all B&W series 2x 802D 1x HTM2D 4x 700s and 2x AWE855 15” subs, studio grade components . This installation is therefore revealing the sound quality limitations produced from the VU+ terrestrial T2 tuner.
My reasons and I’m guessing is the VU driver downgrades the audio stream delivered from the VU HD terrestrial tuner for reason unknown but guess it’s something to do with multiple tuners impacting system resources, even though the problem is present when the T2 tuner is the only tuner in use.

As a last resort the newer VU dual T2/C tuner was fitted and tested recently and that was exactly the same.

Has anyone noticed this limitation?
If this is news to you please compare your terrestrial T2 tuner in HD audio with the same HD channel broadcasting on satellite and report your findings.

I would be interested in your feedback with VU+ Duo2 owners fitted with VU T2 tuners.

If this turns out to be forced product limitation by design then this unit will be for sale, I hope that this is a VU driver issue that needs resolution in due course.

B&W

[maxben]

I'm afraid it's not just the Duo2, it's the same with all E2receivers that I've owned including my current Mutant HD2400 and previous Duo2 and DM8000

You will of noticed the the audio used on the terrestrial HD channels is AAC-HE format, it seems to be a poor implementation of this format on the current OE-Alliance Enigma2.

Although AAC-HE is capable of 5.1 I've only ever seen stereo PCM with an E2 box.

The SD channels use MPEG audio and do not suffer the low volume issue.

Don't know if it's a driver issue, I believe Broadcom officially supports AAC audio so note sure what the actual problem is.

No point in returning the Duo2 for another Enigma2 box as you will just have the same problem, I have no idea how non e2 boxes perform.

[abu baniaz]

Do other images work fine in this regard?

[maxben]

I've only ever tried other OE-A images ie, ATV and it was the same on that.

[Walt]

I've only ever tried other OE-A images ie, ATV and it was the same on that.

Try PLI as I believe it runs from a different core. Don't keep your hopes too high though. I have a pretty good surround system and I've noticed issues with my Duo²'s sound but as soon as it plays an FTP'd movie then sound is back to its impressive best. It's a strange one.

[Trial]

Hi,
OpenPLi is not so different. Very different is Black Hole as it is based on the original image. Perhaps you can also test an original image and create a bug report if sound is bad there too.

ciao

[adm]

Poor HD audio on my Miraclebox with terrestrial tuners was the reason I changed to satellite tuners.

UK HD terrestrial broadcasts are often AAC 5.1 encoded. As my surround sound amplifier doesn't support this format I could only use a stereo downmix with the result that when a program with AAC5.1. audio was broadcast the audio volume fell by 30% to 50% and the sound quality was somewhat of a lesser quality (muffled, lacking directional detail). I think the problem is the stereo donwmix is incorrectly implemented. Not all UK terrestrial HD audio is AAC5.1. encoded so many HD programs do not have the problem.A HD program originally transmitted in stereo allowed my AV amp to decode Prologic II to give an acceptable surround sound. This was not the case with a down-mixed AAC5.1. broadcast.

From what I read none of the Enigma 2 boxes handle AAC5.1 well and none convert AAC5.1. to a Dolby digital format (AC3 ?) in the way that all HD boxes branded with the Freeview/Youview logo do.

Audio coding on (UK) HD satellite broadcasts is different.

[B&W]

Thanks to everyone that replied.
This confirms my concerns exposing the terrestrial limitations with these units and something that is not publicised by the manufacturer or developers and in my opinion is unacceptable especially when audio quality is compromised.

As I previously stated my terrestrial Panasonic DMR BWT800 twin T2 tuner supports separated audiophile sub HDMI audio which outperforms the VU+, although this was £800 at the time. But that’s no excuse for VU+ marketing terrestrial receiver’s with sound quality this bad.

Maybe someone out there on the design team can comment on these products because this is what HD is all about, these products are expected to deliver on sound quality and if not should say so.

This is truly shocking situation.

B&W