Optical Cable Curiosity.
January 16, 2006 2:51 PM Subscribe
I just bought an optical audio cable to plug my PS2 into my receiver. I bought the cheapest one because they ranged as high as 180 CAD and I'll be damned if I'm going to pay that much for a 4ft cable. Is there a difference between the 31 CAD one I bought and the ultra-blah-blah-blah Monster cable that I could have bought?
To agree with quanrinary, optical cables are passing a digital signal. With digital, either you get it perfect or not at all; 0 or 1. If your cable is working, you are getting everything you would from the expensive cable.
posted by GeneticFreek at 3:09 PM on January 16, 2006
posted by GeneticFreek at 3:09 PM on January 16, 2006
Optical cables have a huge markup. I suppose people are willing to pay more because they think it's a "specialty" cable or some such.
It's not.
I bought a 30' length 7 years ago for $50, when I was getting quotes for $100+ a foot from some places. The $50 piece has never failed in any way despite laying on the ground, behind furniture, and occasionally under the feet of furniture.
posted by Four Flavors at 3:11 PM on January 16, 2006
It's not.
I bought a 30' length 7 years ago for $50, when I was getting quotes for $100+ a foot from some places. The $50 piece has never failed in any way despite laying on the ground, behind furniture, and occasionally under the feet of furniture.
posted by Four Flavors at 3:11 PM on January 16, 2006
Know why Monster cables have a lifetime warranty? Because they need it.
Avoid Monster.
posted by TeamBilly at 3:43 PM on January 16, 2006
Avoid Monster.
posted by TeamBilly at 3:43 PM on January 16, 2006
For consumer audio stuff GeneticFreek is mostly correct. In the general case digital signals are never really 0 or 1 except for at very slow frequencies (and audio, even digital audio sampled at maybe 100 kHz is a really slow frequency). Intersymbol interference, cross talk, attenuation and jitter all contribute to making real world signals look pretty crappy. For instance cables pass low frequencies better than high frequencies, this causes the edges of pulses to slew slower and leads to intersymbol interference. Basically your bit spreads out and some of it appears in adjecent bits. There are a lot of things you can do to help with intersymbol interference like spending more money on cable, boosting high frequencies or equalization.
posted by substrate at 3:45 PM on January 16, 2006
posted by substrate at 3:45 PM on January 16, 2006
Avoid Monster.
Seconded. Overpriced and not any better.
posted by BorgLove at 3:46 PM on January 16, 2006
Seconded. Overpriced and not any better.
posted by BorgLove at 3:46 PM on January 16, 2006
You did right. There is absolutely no difference in usefulness between the $180 cable and the $31 cable.
If you hear audible static (or nothing), your cable is damaged. This could occur to either the expensive or the cheap cable. If you don't hear static, your cable is perfect.
posted by jellicle at 4:29 PM on January 16, 2006
If you hear audible static (or nothing), your cable is damaged. This could occur to either the expensive or the cheap cable. If you don't hear static, your cable is perfect.
posted by jellicle at 4:29 PM on January 16, 2006
Best answer: Five or ten years ago the audiophile recommendation was to stick with coaxial spdif cables, and avoid the optical stuff. I'm not sure if this has changed. Regardless, it would apply mostly to high end gear, other considerations (ground isolation in particular) might change the recommendation for mid-fi and consumer gear.
While in practice I agree with the statements so far, I do wonder a little... As substrate says, the bits are bits argument is too simplistic. Older CD Transport / DAC combinations suffered from serious digital signaling issues, mostly jitter. Basically, the timing of the data arriving at the DAC is critical, the DAC clock must be very high quality or the output will be distorted, this is sometimes described as an analogue like problem. Modern DACs often buffer and reclock the incoming data, which is intended to clean up all aspects of the digital signal. I don't know anything much about how successful these attempts are from the audiophile perspective.
Back to the issue at hand... I think quality variation in optical cable is probably more of an issue than in coaxial cable. Coaxial cable is a very mature technology, and there isn't that much variation possible. I guess - I really mean guess - the material used for the fibre optic, and the quality of the end treatment on the optical cable, vary greatly. This does not mean you should buy monster cable! If you are going to spend serious money on an interconnect cable you must do diligent research to make sure that you are actually paying for quality rather than marketing.
Trying to understand these things is complicated by the fact that the engineering community at large didn't appreciate the complaints of audiophiles in the early and middle days of CDs. It turns out that the audiophiles were right, CDs did have major problems. However, CD audio improved enormously throughout the 1990s, today the CD format is considered to be of very high quality.
posted by Chuckles at 4:36 PM on January 16, 2006
While in practice I agree with the statements so far, I do wonder a little... As substrate says, the bits are bits argument is too simplistic. Older CD Transport / DAC combinations suffered from serious digital signaling issues, mostly jitter. Basically, the timing of the data arriving at the DAC is critical, the DAC clock must be very high quality or the output will be distorted, this is sometimes described as an analogue like problem. Modern DACs often buffer and reclock the incoming data, which is intended to clean up all aspects of the digital signal. I don't know anything much about how successful these attempts are from the audiophile perspective.
Back to the issue at hand... I think quality variation in optical cable is probably more of an issue than in coaxial cable. Coaxial cable is a very mature technology, and there isn't that much variation possible. I guess - I really mean guess - the material used for the fibre optic, and the quality of the end treatment on the optical cable, vary greatly. This does not mean you should buy monster cable! If you are going to spend serious money on an interconnect cable you must do diligent research to make sure that you are actually paying for quality rather than marketing.
Trying to understand these things is complicated by the fact that the engineering community at large didn't appreciate the complaints of audiophiles in the early and middle days of CDs. It turns out that the audiophiles were right, CDs did have major problems. However, CD audio improved enormously throughout the 1990s, today the CD format is considered to be of very high quality.
posted by Chuckles at 4:36 PM on January 16, 2006
Response by poster: And if the PS2 had a coaxial digital out I probably would have gone with that. However, it does not. Anyway, I'm glad to see my gut feeling about cable pricing was not incorrect.
posted by ddf at 6:08 PM on January 16, 2006
posted by ddf at 6:08 PM on January 16, 2006
Response by poster: Also, I suppose it's worth mentioning that I didn't even buy the cheapest Monster cable. I went with the slightly longer competing brand for 2 more bucks.
posted by ddf at 6:17 PM on January 16, 2006
posted by ddf at 6:17 PM on January 16, 2006
For a short run, it doesn't matter much. The cheaper cables are plastic and attenuate the signal more than the expensive glass ones, but for a run of six or ten feet, it doesn't matter in the least. Just DO NOT kink or pull on the cable, and you should be fine. Remember, it's very fragile.
If you were running, like, a MILE (which many forms of optical cable can do just fine), then you'd need really good quality, but for 10 feet? You could practically use two mirrors and a wine glass. :)
posted by Malor at 7:54 PM on January 16, 2006
If you were running, like, a MILE (which many forms of optical cable can do just fine), then you'd need really good quality, but for 10 feet? You could practically use two mirrors and a wine glass. :)
posted by Malor at 7:54 PM on January 16, 2006
I once heard a high-end-audio store guy tell a friend of mine that an optical cable was worse than coäx for S/PDIF, because an optical one would "bruise the bits". Snicker.
Bits are bits. The improvements I think Chuckles is referring to were in the conversions between analog to digital and back again. The DAC does have to regenerate a sample clock from the S/PDIF signal, so it's conceivable that jitter there could make it into the output, but even a cheapo DAC these days will do some buffering.
This is all 'way into Golden Ear territory. If you want to spend some money on your audio, spend it on better speakers, DAC, acoustic surfaces for your listening room, or whatever. Don't worry about digital interconnects. Odds are that baling wire and paperclips will still get you a perfect signal anyway.
posted by hattifattener at 11:48 PM on January 16, 2006
Bits are bits. The improvements I think Chuckles is referring to were in the conversions between analog to digital and back again. The DAC does have to regenerate a sample clock from the S/PDIF signal, so it's conceivable that jitter there could make it into the output, but even a cheapo DAC these days will do some buffering.
This is all 'way into Golden Ear territory. If you want to spend some money on your audio, spend it on better speakers, DAC, acoustic surfaces for your listening room, or whatever. Don't worry about digital interconnects. Odds are that baling wire and paperclips will still get you a perfect signal anyway.
posted by hattifattener at 11:48 PM on January 16, 2006
"For consumer audio stuff GeneticFreek is mostly correct. In the general case digital signals are never really 0 or 1 except for at very slow frequencies (and audio, even digital audio sampled at maybe 100 kHz is a really slow frequency). Intersymbol interference, cross talk, attenuation and jitter all contribute to making real world signals look pretty crappy. For instance cables pass low frequencies better than high frequencies, this causes the edges of pulses to slew slower and leads to intersymbol interference. Basically your bit spreads out and some of it appears in adjecent bits. There are a lot of things you can do to help with intersymbol interference like spending more money on cable, boosting high frequencies or equalization."
BRAHAHAHAHA... HAHAHAHA... wow, that's funny
posted by Cosine at 4:32 PM on January 17, 2006
BRAHAHAHAHA... HAHAHAHA... wow, that's funny
posted by Cosine at 4:32 PM on January 17, 2006
This thread is closed to new comments.
basically, you can probably get away with the cheapest cable for whatever given length you want, simply because you're likely to never be moving/connecting or disconnecting that cable.
posted by quadrinary at 2:56 PM on January 16, 2006