Do monoprice redmere cables boost the signal for the audio return channel?

I can find plenty of references that say ARC is supported by Redmere Technology:
http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10255&cs_id=1025501&p_id=9168&seq=1&format=2

However, I can find none that say whether there is any enhancement done on the return audio signal. I suspect the answer is no because 1) the bandwidth needed for the return signal is relative small compared to the video/audio signal going to the TV therefore the enhancement isn't needed as much for ARC and 2) the business end of the Redmere chip is on the TV end. It restores the signal (rather than amplifying the signal). The equivalent chip would not be available on the source end of the cable.

Remember ARC is limited to the bandwidth of S/PDIF signals. So no TrueHD or DTS-HD. That makes it much easier to send the audio signal back.
http://www.hdmi.org/manufacturer/hdmi_1_4/hdmi_1_4_faq.aspx#14
Edited by alk3997 - 12/5/12 at 2:24pm

The Redmere site only says it does equalization and skew correction on the TMDS lines. There is really no reason to do anything to the ARC signal. The way ARC is implemented and the limited bit rate of the audio signal ensures a robust connection. The problem is almost certainly not in the cable. All HDMI cables, including those produced before ARC was introduced, support ARC. The problem is almost certainly in how you have configured you equipment or an incompatibility between pieces from different manufacturers.
Edited by Colm - 12/5/12 at 3:27pm

I didn't realize that. Good to know. I still don't know what the real advantage of ARC is unless your tv doesn't have an optical out. What am I missing?

Which cable would that be?

It is hard to say anything about that cable because of a lack of specifications. One warning sign is that it claims to be a 30' high speed cable. If you are going to replace the cable, I would recommend going with a known quantity, at least a known wire gauge. Monoprice is well thought of around here. There are others. A 22-24 AWG cable is usually used at the length you are dealing with. There is no way of telling what it is on the cable you linked to. It looks to me from the picture like it might be smaller wire, but it could just be a real thin sheath. If the wire is smaller, it might be possible that it affects the ARC signal enough at 30' to make it unusable, at least with the combination of electronics you are using.

I'd certainly be nervous about that cable and ask for their high speed certificate (they should have one). Since we all know that the maximum length of a certified high speed cable is approximately 25 feet (5 feet is not within the "slop"), it would be difficult for them to have a 30 foot High Speed cable. However, if they do that means they have certified it at a laboratory and therefore should have a certificate.

Also this phrase, "Transfer Digital Audio and Video signals at warp speed of 10.2 Gigabits per second," is a warning sign. The only way to get to 10.2 gpbs is to use the maximum bandwidth available on the cable. If you are running at 1080p/60 then you would have a bitrate of 2.78 Gbps. If you enabled deep color then you would have 12 bits per pel instead of 8 bits, so your bitrate would be 4.17 Gbps. Now that's just video, so audio and other data goes across the HDMI cable as well. But, the point of all this is that the content (and chipset) chooses the bitrate and not the cable. So to imply that because you have this cable, you can transfer at 10.2 Gbps is, at best, misleading.

You can think of the cable as a water pipe. Just because you make the pipe bigger doesn't mean more water will flow - the water source would also have to increase the overall water rate.

In the end, I suspect if you used a known good HDMI cable, you would not have had the problems you had and who knows what pins were actually connected with the cable you used.
Edited by alk3997 - 12/6/12 at 7:13am

I think you got it. It's for watching OTA or cable using your TV's tuner and wanting the sound to come out the speakers connected to the AVR. A S/PDIF connection does the exact same thing (assuming the TV has a S/PDIF output).

^^^ that's one of the reasons that I'm not a big fan of smart tv's, especially if you have to use ARC/CEC. Give me an optical cable, an external STB like a Roku or AppleTV2, a Harmony remote, and I'm a happy camper

Unfortunately, the only way to make sure CEC works is to use equipment from a single vendor. Otherwise, you are likely to wind up with something less than the full functionality you are looking for. The CE companies really dropped the ball on this one. Most people who want the capability in a mixed environment just use programmable remotes, with or without and IR or RF extender.

One more thing about ARC. At 30' you might want to consider using a HDMI cable with ethernet. The ethernet and ARC signals share the same wires, and the changes made to the cable to support ethernet are beneficial to the ARC signal as well.

BTW if the cable change fixes your problem, the origial cable still may not be the cuplrit. It could be the electronics at either end. But it is really a moot point if it fixes your problems, and the only way to tell for sure would require tens of thousands of dollars of test equipment.
Edited by Colm - 12/6/12 at 8:25pm

If that cable uses this Redmere technology, then it does support ARC. http://www.redmere.com/business/pre1692.php

Not sure if ARC is boosted or not but let me know if your cables work. I'm buying similar cables.
Edited by Donat76 - 12/11/12 at 9:27pm

From what I understand, their customer service and return policy are both top shelf so it's not like you would have to eat it if it didn't work. As long as you can potentially be without the $$ for a short period, there shouldn't be anything to worry about.

i am using a 10' redmere cable on my brand new panasonic GT50 from my brand new Pioneer SC-1222k and cannot seem to get the ARC to work. it's not that big of a deal because i have a STB and a Roku....but there IS a youtube app on the TV i would like to use. As of now i cannot get the sound to work with this cable. the Viera link youtube app is really neat. better than the damn PC in my mind.

http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10255&cs_id=1025503&p_id=9428&seq=1&format=2

i will try a different HDMI cable later today.

I got ARC to work with the Panasonic VT50 YouTube app just fine, using a Redmere 30-foot cable. There is one specific HDMI output of the Panasonics that is ARC-enabled. I had it connected to my Oppo BDP-103 since my AV receiver doesn't support ARC. I had to switch the input on the Oppo to indicate ARC, and after a moment it synced up and I could hear the audio.

It's not dishonest. With the error-correction included, all high-speed certified HDMI cables transmit about 10 Gbps. (I don't have the exact number here on my smartphone). True, such equipment doesn't exist in the CE industry yet, but if its a certified cable, it can do that.

As most of us know, there is no video or audio error correction with HDMI. Please check facts before posting.

You also missed my point, which was 2 weeks, 5 days ago. The point was that the cable doesn't control the speed of the transmission. The chips in the source establish the speed of the transmission. The cable does not. Therefore the advertisement is misleading. Again, understanding how things work is important in this forum.

There is error correction built into the digital signal. The trouble is that if the errors are bad enough that the ECC can't correct them, there is no way to request a retransmission.

Really? What is your sources for this? Mine are:

http://www.bluejeanscable.com/articles/dvihdmicomponent.htm

"Second, it is a flawed assumption to suppose that digital signal handling is always error-free. HDMI signals aren't subject to error correction; once information is lost, it's lost for good. That is not normally a consideration with well-made HDMI cable over short distances, but can easily become a factor at distance."

http://www.audioholics.com/education/cables/whats-the-matter-with-hdmi

"A packet that doesn't arrive on a computer network connection can be re-sent; an HDMI or DVI signal is a real-time, one-way stream of pixels that doesn't stop, doesn't error-check, and doesn't repair its mistakes--it just runs and runs, regardless of what's happening at the other end of the signal chain."

http://www.avforums.com/forums/tvs/804190-do-hdmi-dvi-d-signals-have-parity-bits.html

"There is TERC4 coding used at source , which is error reduction coding , intended to reduce the likelihood of errors , but this is not error correction per se. There are some ECC codes in the Data but as there is no facility for re-transmission these are merely a flag for bad data and are not used for correction as such."


So there is no correction done of the audio or video data, and therefore there are no error correction bits. I'm sure you know that when HDMI came out the data rate was pushing the state of the art without error correction. The required use of error correction would have killed the format since many HDMI chipsets overheated without error correction.

I am interested if you have sources that state otherwise.

Yes, there are error correction codes built into HDMI for the data island packets, but not for video. See the HDMI 1.3 specification for details. It hasn't change in 1.4 If a bit flips in the video data, you just get the wrong color. There is no way to fix even a single bit error.
Edited by Colm - 12/25/12 at 11:38pm