Old Denon AVR-3801 - Surround sound decoding

RufusW5

Novice Member
I'm pretty much on the page that I need a new AVR, but just wondered if there are any other solutions to this..

I've learnt a lot just recently, about how toslink is severely limited! My old Denon AVR-3801 won't read bitstream either, so I have two options:
1 - some kind of external decoder with 6 channel analogue outputs, that can decode DolbyHD and Dolby TrueHD (I think!)
2 - A new AVR

I just wondered if such a thing exists? I've been googling like crazy and found nowt..
 

gibbsy

Moderator
It's time for a new receiver. No doubt it's given years of service but the technology is showing it's age. Newer receivers have better EQ and the new Denons and Marantz are really easy to set up. This years models all have the latest updates to carry you into the 4K domain.

The HD audio is much better than it's SD counterpart and even the entry level can give you seven channels of amplification as well as Atmos/DTS X.

Basically what you are talking about with a decoder is a processor and they can be as expensive, if not more so than a receiver. To give a better answer you will have to come up with a budget as well as what speakers you are driving.
 

RufusW5

Novice Member
That's for the reply, at the moment I'm driving a set of Mission M72's, M7C2 centre and M5DS surrounds. With a JAMO 410 sub.

I built it on a budget in view of progressively upgrading it!

I'm thinking around about £400 for my new AVR, just been reading g reviews for the Denon AVRX2500H and the Sony STR-DN1080.

Both seem well received, although at present I'm swaying towards the Denon.

My intention was originally to upgrade the speakers first but it's sounding like a new AVR would improve the HT experience significantly at the moment!

I'd appreciate your thought :)
 

Leelo

Active Member
That's for the reply, at the moment I'm driving a set of Mission M72's, M7C2 centre and M5DS surrounds. With a JAMO 410 sub.

I built it on a budget in view of progressively upgrading it!

I'm thinking around about £400 for my new AVR, just been reading g reviews for the Denon AVRX2500H and the Sony STR-DN1080.

Both seem well received, although at present I'm swaying towards the Denon.

My intention was originally to upgrade the speakers first but it's sounding like a new AVR would improve the HT experience significantly at the moment!

I'd appreciate your thought :)
I think you have the right approach there AV receiver first as it’s the core of any upgrade paths you will follow

Without knowing what sources you use it’s difficult to recommend the next move. If seriously considering 4K viewing then the next step should be a new screen. Personally I wouldn’t worry about the speakers till last
 
D

Deleted member 39241

Guest
You could try using the Denon 3801 as a power amp via the ext. in inputs. But to do that, you would need a new AVR with multi channel pre-outs, so the Denon 3x00 or better or the Marantz 601x or 701x models.

That way you could power some speakers from the new AVR and some from your current one.

Not sure if it would add any audible benefits or worth the hassle, but the option is there for experimentation if you want to.
 

RufusW5

Novice Member
I think you have the right approach there AV receiver first as it’s the core of any upgrade paths you will follow

Without knowing what sources you use it’s difficult to recommend the next move. If seriously considering 4K viewing then the next step should be a new screen. Personally I wouldn’t worry about the speakers till last
Thanks, I only really use one source - my Xbox one, it serves as a Netflix / Prime video box, blueray player and of course a games console.

I don't really watch live TV, there's just too many adverts (I wouldn't miss my BT box if I binned it, makes me wonder why I still have a TV license).

The AVR is currently Toslink'd to the XBOX, which seems to work ok in fairness. I don't have a 4k TV get, my TV is a 47" 1080p LG, I'd rather have HD sound than 4k TV where I have to chose, although I'm sure eventually I'll upgrade my TV too.

I have to say though, my headphones seem to make much more effective use of the xbox toslink audio output than my AVR does, which seems to be due to that they can decode bitstream (AC3?). It's a shame the 3801 can't decode bitstream!
 

Leelo

Active Member
To be fair if the Xbox can decode bitstream ( I’m not familiar with games machines at all ) it should send the 5.1 channel data as PCM to the Denon which should be able to decode that into audio obviously you still will only get The older non hd formats via Tos link does the Xbox have analog output as the Denon does have analog inputs.

I don’t know about the headphones you have but if they connect via a normal 3.5mm or 1/4 in analog socket then they are getting audio decoded by the Xbox and not receiving any form of digital signals at all. However your comments above indicate that they are connected using a optical cable which is interesting and. I suppose if that’s the case then yes they are decoding AC 3 Dolby. I have heard of headphones for gaming that do this and I suspect the reason why they sound so effective is because they are directly on ear so any effect they generate are fed straight to the head and hence no other interference from room interaction is diffusing the sound field.

My Yamaha receiver uses a standard analog headphones socket but they claim that it can be used with normal headphones and still recreate the 5.1 effects of surround sound via so clever jiggery pokery inside the receiver. I’ve never tried this as I don’t use headphones at all
 

RufusW5

Novice Member
It's a wireless headset, the small transmitter has an optical input and optical pass through.

The annoying thing is, if I set it to bitstream then my headset works great but my AVR can't read the pass through.. and my TV will only send PCM!

So even if the information is in the PCM signal I think it gets lost before it goes to my AVR.. which is a shame.

The Xbox doesn't have any analogue outs, but the AVR does have analogue inputs (for 6 channels). It's a shame really, all that's missing for AC3 is a decent AC3 DA converter! I know AC3 is old hat now anyway, but based on my headset, bitstream Vs PCM, PCM does seem to lose a lot of the effect of surround (though somehow not all of it).

According to the spec sheet the Xbox One S can send DolbyHD, Dolby TrueHD and Atmos over HDMI and will send DD and DTS 5.1 via Bitstream Toslink, however PCM.. seems mostly intended to be used for stereo, I guess any form of PCM 5.1 is probably severely compromised, although I could be wrong.

Such a shame my old AVR won't decode Bitstream audio!
 

dante01

Distinguished Member
PCM can consist of as many channels as the audio it originated from had. The issue with your setup is that S/PDIF optical is limited to just 2 channels of PCM data. The issue isn't with PCM as such and is with how many channels of PCM data optical can convey. If not bitstreaming a format from a source and having the source device itself decode it, the resulting PCM would be the same PCM as the decoding onboard the AV receiver would result in prior to that receiver feeding that PCM data into its own DAC. Bistreaming audio doesn't result in superior audio quality and HDMI can convey multichannel PCM. PCM isn't an audio format and is the lossless base level digital data most audio formats are used to compress, package and convey to other devices.

Blu-ray Disc Audio - Bitstream vs PCM Output - Which Is Best?

What's PCM Audio, and What Does It Do for Your Home Theater?

The only real advantage to bistreaming is the fact that the file format will be displayed on the AV receiver when detected. It would also be required in order to convey Atmos or DTS:X metadata. Such metadata is packaged within formats such as Dolby TrueHD or DTS-HD MA so you'd need to bitstream those formats to convey the metadata. If you were using a source's multichannel analogue outputs then the source would have first decoded the format resulting in PCM data prior to then passing that data through its own DAC and then outputting the resulting analogue signals via its analogue outputs. Note that S/PDIF cannot convey TRueHD or DTs-HD MA, but neither does your AV receiver include decoding for such formats or the HDMI inputs needed to access them.

PCM can technically exceed what is allowed via HD formats such as DTS-HD Master Audio and Dolby TrueHD. PCM is digital data that is lossless and uncompressed.

The XBox can be configured to bitstream audio as opposed to being limited to decoding it itself and outputting multichannel PCM. As said though, you cannot convey more than 2 channels of PCM via S/PDIF optical.

Also note that the Denon AVR3801 is able to decode both Dolby Digital and DTS 5.1 as well as 6.1 DD EX and DTS ES. You should be able to bitstream these from the Xbox to the receiver via optical?
 
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RufusW5

Novice Member
Thanks for that, some good info there! Ive been playing with my AVR, and you're right - it can decode DTS over bitstream - when I connected up the TOSlink it auto-detected initially but didn't auto detect the change to digital DTS / DD, I hadnt realised that after setting up the Xbox to send DTS bitstream I needed to push the DTS button on the AVR.

I know that sounds ridiculously obvious, I had it set to Dolby Pro Logic before, I haven't been all that familiar with the different formats - and now I realise Dolby Digital and Dolby Pro Logic are different things (I think...).

From what I can tell, Dolby Pro Logic is a 5.1 format taken from an essentially stereo signal, if I set it to bitstream DD it doesn't pick it up - so I guess Dolby Digital and Pro Logic must be two different things!!

I'm learning...

So 5.1 surround is working great now but just DTS, I'm sat wondering how much difference HD sound actually makes? (I'm guessing the change is significant based on what I've read!).

From what I read about Bitstream, because it's essentially compressed, bitstream can send standard 5.1 over toslink for DTS and DD (But TrueHD, DolbyX, Atmos and DolbyHD need HDMI for bandwidth reasons) - but because PCM is uncompressed toslink only has enough bandwidth for two channels.. is that right?

I'm happy that I now have DTS but I'm still very much contemplating a new AVR for HD 5.1 - I'll have to go see if I can have a listen to one somewhere!

I do appreciate the discussion, it's really helping me wrap my head around the many different formats and capabilities.
 

dante01

Distinguished Member
Pro Logic would have been something you used in conjunction with 2 channel audio in order to either extract Dolby Surround channels matrixed into the 2 discrete channels or to crete pseudo surround channels from audio that was only initialy ever intended to be played as a stereo source. Dolby Digital is a format that can consist of up to 5.1 discrete channels in its most basic form or even 6.1 channels in its EX variant.

You can bitstream both Dolby Digital or DTS to your receiver via optical, but you are correct when assuming you'd need HDMI if wanting to bitstream HD formats such as TrueHD or DTS-HD MA or indeed multichannel PCM to a receiver.
 
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RufusW5

Novice Member
Pro Logic would have been something you used in conjunction with 2 channel audio in order to either extract Dolby Surround channels matrixed into the 2 discrete channels or to crete pseudo surround channels from audio that was only initialy ever intended to be played as a stereo source. Dolby Digital is a format that can consist of up to 5.1 discrete channels in its most basic form or even 6.1 channels in its EX variant.

You can bitstream both Dolby Digital or DTS to your receiver via optical, but you are correct when assuming you'd need HDMI if wanting to bitstream HD formats such as TrueHD or DTS-HD MA or indeed multichannel PCM to a receiver.

That's what had me confused when trying to figure out why it wasn't working, partly that in auto mode I thought it would auto detect the source type..

But mostly that I didn't realise Dolby Pro-Logic and Dolby Digital are actually two different things!

Everyday's a school day...

Now I'm sat wondering whether or not to buy a new AVR for HD audio, I'd sold the idea to myself before standard definition 5.1 was working properly..!
 

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