Dolby digital plus or Dolby Digital?

Dolby Digital is the audio standard for NTSC HD TV...

Just my $0.02...

has nothing to do with Samsung TV's...

I have a more basic question than 'which is better?' My question is WHY - as in why does the Roku2-XS box require Dolby Digital Plus for services such as VuDu and Netflix 5.1 surround? Shall we all go out and replace late-model high-quality receivers that have a dozen audio codecs but not DDP?

It's not that it "requires" it rather it's the source format chosen by Netflix and VuDu which the Roku simply passes through to the AVR.

DD+ can be more efficient than DD, giving you the same quality at a lower bitrate. A decade after DD was introduced, audio compression technology had improved, not just at Dolby (compare AAC at 256kbps vs MP3 at 320kbps). Does ignorance really need to be expressed in such a condescending tone? Every single DD+ decoder is capable of converting the bitstream to legacy DD, which can be decoded by older receivers. By "older" I mean made over 5 years ago. I doubt you'd find "late-model" receivers made since 2007 that don't decode DD+. So, no need for us to "all go out and replace late-model high-quality receivers", since current and legacy models are covered.

I'm using a Sherwood RD7502 and would then like to know how to '...convert the bitstream to legacy DD...'. Sherwood has no information on such a conversion - perhaps you can assist?

Have not received any response from you or anyone else as to 'conversion'. Will I be hearing from you?

I'm not an expert but after checking the specs of your receiver online, it apparently does not decode DD+. What the previous poster was referring to was that a receiver that can decode DD+ will be able to down-convert a DD+ signal to regular DD if necessary. (Although I can't imagine why you would need to do that)

Your Roku box should be able to convert Dolby Digital Plus to plain Dolby Digital.

This is not correct. After doing a lot of trouble-shooting of my own on the Roku forums, I can say with 100% certainty that no Roku models convert dolby audio in any way. All they do is pass the signal through without touching it. I assume Roku does this is to avoid the cost of licensing the Dolby Digital decoders.

Well, I did say "should". Anything that claims to support Dolby Digital Plus, like Roku's Netflix client, should support conversion to Dolby Digital. Dolby Digital Plus was designed with this in mind, it was made easy to convert to Dolby Digital, so I'd argue Netflix and/or Roku has implemented this incorrectly.

Does your RD-7502 decode audio thru HDMI or do you also have to connect an optical or digital coax cable for sound?

And if it doesn't docode HDMI audio, how is your Roku2-XS connected for audio?

To the best of my understanding, if Roku does any kind of decoding to a Dolby signal, they have to pay licensing fees to Dolby. They can pass a Dolby signal with no decoding however without paying the licensing fees. This is how they can claim to offer DD+ surround via Netflix without paying the licensing fees... they basically pass the buck onto the end-user requiring them to have a way to decode or downgrade the signal through their own equipment.

The manual for the box simply states that the HDMI connection to the HDTV and from there to an external amp is all that's needed. There's an A/V port as well, but manual states it's to be used for standard definition only. My Sherwood RD7502 HDMI video amplifier(pass-through only) has multiple audio codecs available, but significantly none of them is Dolby Digital Plus. The VuDu tech support department, for example, states that this is a major deficiency at the moment with the Roku2-XS box and should be addressed by Roku(but nothing yet). It's very frustrating to have superb image quality on 1080p offerings from Netflix and VuDu but audio limited to old-fashioned stereo only, despite a late-model high-quality HDMI video amplifier.

You should do more fact checking.

1st, your Sherwood is no where near the "high quality amp" as you purport it to be. Look at all reviews on your low-end, low-price (read - corner cutter) "high quality amp" and it staes it is a decent (cheap) AVR "as long as audio thru HDMI isn't a concern", along with " Note: HDMI is for video ONLY, you still need to connect the DVR and blueray/etc with the optical cables."

As stated before, your AVR is cheap and NOT high quality. Not being a jerk, just stating facts. Sorry to burst your bubble, but posts like your are false and misleading and you should refrain from posting gibberish like this before you investigate (read -GOOGLE) the specs on your own equipment first. It took me all of 40 seconds to find all the details/specs on your AVR.

Wrong again. You appear to automatically equate higher price with higher performance(not so, as last week's Consumer's Reports on the Cadillacs and Lincolns will attest). Sherwood, a local Southern California manufacturer has been a poke in the eye to higher-priced competitors around here for a long, long time. I've compared $699 receivers with the Sherwoods and find the latter every bit as good for a lot less. I'm one of those pesky 'bang for the buck' buyers who can afford to spend much more, but prefers to get the best value for the dollar. As to the RD7502(pass-through only) and its sibling RD7503, the '02 has features I need which the '03 does not, such as certain connectivity options(here are some reviews, up and down the lot: http://www.testseek.com/home_electronics/hifi/receivers/sherwood_rd-7502-p-679011c8-1582-c3f6-b79b-2c04ff671da9.html). That old saying 'a fool and his money are soon parted' is targeted by manufacturers to idiots impressed by logos and names which are of little practical value. I can only assume that you get all your political info from Fox News(?)

You get what you pay for, up to a certain point. You cannot expect to get a $3.00 cup of coffee for $0.25.

The concept that a higher price means higher quality is one of the all-time bogus theories being peddled by many providers. After all, if you can get a lot of people to believe it, you're way ahead of the game, Fortunately, independent expert sources, such as Consumer Reports, often debunk this theory(the Cadillac and Lincoln references most recently). Here's another really GLARING example that I think merits close attention: online prescription eyeglass services like Zenni Optical and EyeBuyDirect are so VERY much cheaper for comparable(and sometimes better) products it's startling: try frames and prescription lenses including scratch-resistance and anti-glare coatings for as little as $30; Lenscrafters for the same thing? Try about $100(and no, that combination is NOT done 'in about an hour'). So your thesis is in general true but way off the mark in the real world. The Sherwood amps here in Southern Cal are a prime example. They match up with $699 competitors for hundreds less.

In the normal course of events, the receiver will use the HDMI handshake to tell the source device that it does not support an advanced codec such as DD+ and the AVR will instruct the source to send a format it can handle. That answers your earlier question about conversion - which is handled by the source device, not the AVR. (The TrueHD encoding package includes a DD 5.1 track that is supposed to be sent when the receiving device can't process the higher resolution codec. I believe the same is true of DD+.)

So. what happens with audio when you connect your Roku2-XS to your receiver? Do you get any sound? If so, what format does the Roku output? I would assume you'll get stereo sound, at least, since you are hardly the only person with an older receiver that lacks decoders for the newer codecs.

Your call to VuDu seems to sum up the situation. Roku should handle older equipment the way nearly every other vendor handles it, where the box will output DD 5.1 when the HDMI handshake rejects DD+. But, apparently Roku doesn't work that way, which is a problem with a particular vendor. Upgrading your AVR would solve this, of course. Upgrading would also provide lossless audio with Blu-rays, which you can't get with your current AVR.

What do I hear via the amp? So long as the Roku2-XS is set for STEREO on sources such as Netflix 5.1 or Vudu HDX 5.1, a plain old stereo mix is heard. If, however, the box is set to 5.1, there is no sound whatsoever from the amp - or even the HDTV(Panasaonic TH65PZ850U). Since both Netflix and VuDu simply state that they've referred the issue to Roku, it appears at this time that there is no solution for thousand and thousands of amplifier owners which do not decode DDP. Any suggestions?

I suspect you already know the answer. Using the stereo output is the only current option on your Roku. You could get some other streaming device that supports 5.1 and has a legacy digital output. Lots of Blu-ray players include streaming services. Or, get a new AVR, which will have other benefits besides 5.1 streaming.

I understand your frustration. I also have an older receiver without HDMI, a Denon 3805 that works beautifully. We have an older Roku with a digital output, but it doesn't support 5.1 on Netflix. Our AppleTV does, however, and we use it for the small number of 5.1 Netflix offerings. Unless you upgrade, you'll have to accept the limitations of your equipment now that HDMI has become the interface of choice.