Greetings from a bemused Ppuker

[CatherineB]

Snapfish do lovely photobooks - the only I've seen, I have to admit. My bro and SIL did a great photobook of their wedding.

 

[Gareth Hughes]

For something a bit more than just a photobook, I've been very pleased with the quality of what you can produce using Blurb (though I wouldn't bother with the extra expense of their hardbacks)

 

[AMc]

I can't see any reason to put yourself through the pain of home photoprinting unless you desperately want to control the image output and have the skills, time and cash to support that hobby - or you want the images in a few minutes rather than a couple of days. If you want to print 20 odd 6x4 then I remember setting aside an afternoon!

I've bought online prints and photobooks from Truprint (a.k.a. Snapfish), Boots and Photobox.
Photobox have won on quality and speed of delivery for me on prints though they are sometimes a bit more expensive the difference between 8p a print and 10p a print is quickly forgotten.

If I upload a set of images to Photobox in the morning and place an order I generally get them dispatched that day and delivered the next on their standard delivery which makes them more convenient and quicker than a trip into Norwich to use a photoprinter at Jessops or Boots.
Snapfish / Truprint who I still use occasionally seem to take longer to send them which doesn't always matter but I'm usually impatient to get the prints after I've mucked around sorting the images and uploading them.

The Gadget Show ran this comparison test recently which rated Photobox, Tesco and awarded their overall winner to Snapfish.
http://fwd.five.tv/gadget-show/videos/other/online-photo-printing

Photobox's photobook was better than Snapfish but I ordered them years apart so probably not a fair comparison.
I was very impressed with Truprint/Snapfish's acrylic block photogift which we gave as a 40th present & a mug which we gave my mum. I agree you're well advised to sign up with a few services and wait for the offers if you want to do this kind of thing - I just keep the most recent email from each in case I decide I want to order something.

I bought a small Brother HL2030 black and white laser printer 5/6 years ago. I've replaced the toner once in that time (£40). As the machine is still in production the consumables are cheap and readily available.
One of the big advantages of laser over inkjet is that the last can put out about 10 sheets a minute and takes a couple of seconds to warm up. It used to drive me insane watching the inkjet slowly draw each sheet when you just wanted to get a map from google or an email to take to the shops to refer to.

The only person who misses a home colour printer is my little girl but she has plenty of crayons and pens

As for speaker cable being expensive - I'm always horrified by what HiFi shops charge for simple cable £1 a metre upwards!
I've always ordered it online often from www.cpc.co.uk at around 20p a metre in bulk. I also have one speaker connected with a spare length of 5amp twin and earth
The only time I've bought 'proper' cable was when I was wiring up the 5 speaker surround sound in the front room - as the speakers were wall mounted up high and I didn't want to see the cables or channel the original plaster (!) I bought this flat, self adhesive stuff which went around above the picture rail and now it's painted is almost invisible. I'd definitely recommend it where there are visible runs as it takes minutes to stick compared to clipping and trunking cable.
http://www.audiovisualonline.co.uk/dynamic/eshop_products.set/ref/312/ixos-xhs233-adhesive-backed-flat-speaker-cable/display.html

 

[Penners]

As for speaker cable being expensive - I'm always horrified by what HiFi shops charge for simple cable £1 a metre upwards!

A recent consumer (Which?) report blew the gaffe on special data cables. They tested HDMI cables priced from somewhere around £3 (made from turnips) to £39 (made from genuine gold-plated Martian Kryptonite) and judged there to be no difference whatsoever in the quality of the signal.

I wonder whether the same is true of your 5A TWE compared with over-priced hi-fi cable.

 

[Flyfisher]

The 'gold-plated Martian Kryptonite" cable debates (you forgot about them being uni-directional :lol: ) were amusing enough in pre-digital days when there was at least some tenuous theoretical link between distortion of an analogue electrical signal and the quality of the received signal (assuming one was blessed with "Golden Ears" and could actually hear things that sophisticated test equipment could barely measure).

But one of the defining characteristics, and breakthrough advantages, of digital technology is its ability to transmit data from one device to another with absolutely, definitely, 100% guaranteed, accuracy for 'fidelity'. Thus, the concept of a "quality" digital cable really just boils down to its physical characteristics, e.g. is it robust enough not to break when repeated connected/disconnected?

Still, all's fair in the marketing wars. :lol:

 

[Penners]

But despite the music being recorded digitally, isn't the signal from amp to speakers still an analogue one? Or am I behind the times (again!)?

 

[Flyfisher]

Yes, amp to speakers is still analogue, so don't throw out all your gold-plated Martian Kryptonite cables just yet. :wink:

I was really following on from your HDMI cable example, which is a digital interface, with 1s and 0s in and 1s and 0s out, so very little scope for any subtle distortions of the signals, meaning that a cheap cable will be just as good as an expensive one (for the data transfer anyway - physical robustness is a different matter).

 

[Moo]

Gosh, that's all so interesting!

If only I could have read this thread a month or so earlier.

 

[downshifter]

Has anyone any views on wireless speakers? As I understand the system you wire up a small transmitter to the amp and off you go. The big drawbacks are expensive to buy and run (uses batteries or mains). Big advantages no unsightly cables to trip over or chase into walls and can move speakers to any room in the house or outside.

 

[AMc]

Has anyone any views on wireless speakers? As I understand the system you wire up a small transmitter to the amp and off you go. The big drawbacks are expensive to buy and run (uses batteries or mains). Big advantages no unsightly cables to trip over or chase into walls and can move speakers to any room in the house or outside.

There will be some loss in quality compared with a CD or other high bandwidth source and potential for interference as the ones I've seen are using the same 2.4GHz band as WiFi, DECT phones, baby monitors etc. On the other hand the convenience is obvious- rechargeable batteries - particularly Enloop style ones that don't self discharge are a good solution and more cost effective than disposable batteries.

If you can move the music digitally (over WiFi as lossless audio or a high quality MP3) and decode it at the speaker end it should work better - something like The Logitech Squeezebox Radio cheaper at John Lewis (Other similar systems are available).

If you have music on an iPod/MP3 player then I can heartily recommend The Logitech Pure-Fi Anywhere™ 2 which you can get for about about £70 at Richer Sounds. We've had one for a couple of years. It sounds great, is capable of playing quite loud and has a rechargeable battery that genuinely lasts for about 8 hours. The only thing that is poor is the little credit card remote which seemed to only work from a couple of feet away and the battery died in a couple of months (the two may be connected but we haven't bothered replacing the battery as it's one of those fiddly coin cells).

Of course if you want the radio then an FM radio is cheap and hard to beat

I fitted weatherproof speakers as part of our work hard wired to a point in the Vinery connected to an amplifier so I can play back music, radio etc. The speakers were about £25 a pair from CPC made by Prosignal but they don't stock them any more. The front grills have gone rusty but they work fine. In the summer I'll take the grilles off and spray them if I have the inclination and time.

In a previous house I fitted some excellent Bose outdoor speakers that I got on eBay - previously used in a pub. Again I hard wired them back to a HiFi and speaker switch in the kitchen. The only thing to watch for was inadvertently leaving them on and blasting music at the neighbours for days until you went outside again

If you're fitting speakers in the house and don't want to channel the walls (who would unless they were totally redecorating and the plaster was modern?) then the flat self adhesive cable I linked to is excellent and made a painful, ugly job clipping cable into a short, easy one.

 

[Flyfisher]

I've never used wireless loudspeakers but my understanding is that they are usually based on FM transmission techniques, so the quality should be on a par with FM radio. Truly wireless operation means battery operation and this, I think, tends to mean fairly low amplifier power in order to maximise the operating time. This may or may not suit your listening habits. Relaying R4 may be fine with a few watts of music power but probably not for blasting out some Metallica - though if you only want to relay R4 then it's probably cheaper to just buy another radio. I'd expect battery operation to be fairly expensive, especially if (when?) the loudspeakers are absent-mindedly left on overnight.

If you already keep your music on a PC and also have wifi at home then there are various options to play music around the house without wires. I use a couple of these widgets http://soundbridge.roku.com/soundbridge/index.php, through which I can access all the music on my PC over wifi and listen via powered speakers or a hi-fi system. These particular products are discontinued but there are other similar devices available. The Apple TV product looks quite nice, especially if you use iTunes to store your music, and it also handles video and photos (via a standard TV) as well.http://store.apple.com/uk/browse/home/shop_ipod/family/apple_tv.
They all need mains power though, so not totally wireless in that sense.

Edit: Oops - posted before I saw AMc's previous post, though we seem to be saying more or less the same sort of thing. :wink:

 

[AMc]

A recent consumer (Which?) report blew the gaffe on special data cables. They tested HDMI cables priced from somewhere around £3 (made from turnips) to £39 (made from genuine gold-plated Martian Kryptonite) and judged there to be no difference whatsoever in the quality of the signal.

I wonder whether the same is true of your 5A TWE compared with over-priced hi-fi cable.

Back when DVD was just arriving in the UK I was really into home cinema (as opposed to now when I can't afford the toys so I've stopped looking )
There was an excellent experiment where a researcher took a super dooper moulded by the godsTM digital audio cable and compared it with a metal coat hanger with RCA jacks soldered to each end. Audibly they were identical, when run through test equipment they produced exactly the same number of errors - i.e. essentially none.
Seems to have been lost in the ether since I saw it in 1999 but this test proves roughly the same point on analogue speaker signals
Audiophiles can't tell the difference between Monster Cable and coat hangers[/urk]

As I understand it the signal over HDMI cables (like cat5 and 6 data cabling) run at high frequencies and over 10m + runs they are more susceptible to interference and signal loss. As there is error correction as part of the signal then this isn't apparent until it reaches a fairly serious point but it does degrade the signal. Over 2 or 3m lengths I have no problems with using £3-4 cables from CPC or even the pound shop at a push

You can also buy HDMI repeaters that connect two leads together and use power from the source to amplify the signal output. I'm not sure how that works but I assume that longer cable runs were considered when the HDMI interface was put together to cover commercial installations.

If I ever have the cash to replace my amp and projector for HD then I'll need a 15m HDMI lead - I might stretch to £20 for that
The main reason I don't buy the cheapest interconnection cables is I don't want the quality of the soldering to be so weak that you get loose connections from plugging them in and out a couple of times. I've spent too much time in my life trying to work out why a speaker drops out once in a while to finally discover its a dry solder joint on an old lead.
I once switched out a surround sound speaker to discover the speaker was fine, just when really loud bits in the film used that speaker it caused the picture on the wall underneath it to rattle against the wall

I used a bit of 5amp lighting flex as I didn't have a cable to hand to wire up a 'centre' speaker on my home cinema. As the cable was thick copper and the appropriate length I put it in and figured I'd replace it at some point. Unsurprisingly it works fine and I haven't bothered. As speaker outputs carry reasonable currents then a decent, thick conductor is all you really need.

 

[Penners]

The Logitech Squeezebox Radio

That's a highly informative treatise, thanks AMc.

The above radio is advertised as a "limited edition", which seems very odd. I thought the whole point of such consumer appliances was that mass production in vast quantities made them affordable.

 

[AMc]

You're very welcome - it's only the white casing that is "limited" the product is generally available I believe.

 

[Flyfisher]

Back when DVD was just arriving in the UK I was really into home cinema (as opposed to now when I can't afford the toys so I've stopped looking

I recognise that scenario only too well. :lol: :lol: :lol:

As I understand it the signal over HDMI cables (like cat5 and 6 data cabling) run at high frequencies and over 10m + runs they are more susceptible to interference and signal loss.

That's an interesting point, though it moves us into more complexity about what's going on inside these cables.

The electrical signals that are sent along these cables are, indeed, susceptible to interference and all manner of losses and distortions, and these distortions happen all the time, even over quite short lengths of cable. But in a digital system the fidelity of the electrical signal doesn't matter as long as the receiver can correctly determine if the horribly distored signal being received represents a digital '1' or '0'. The data and the signal are two very different things. If the receiver can correctly extract the digital data then perfect transmission is achieved, regardless of whether the electrical signal was conveyed over the highest possible quality cable or a wire coat hanger.

A good analogy is morse code, which is a sort of digital signal. All that is necessary to correctly receive a morse code message is to be able to distinguish the lengths of dots and dashes (and the gaps between them) in the transmission. Morse transmission also works at two levels - the data and the signal. At the transmitter end, the data might be a hand-written message and the morse code signal might be a nice 'clean' tone of a specific frequency and volume. At the receiver end, the morse code signal is probably a badly distorted tone, possibly of a different frequency, certainly of a different volume and with lots of noise and crackles. But the listener can easily recognise the dots and dashes within all that noise and distortion and write down the message on a piece of paper, exactly as the original message was written down. Thus, we have 100% accurate transmission of the data even though the signal was thoroughly distorted. That's the beauty of digital technology.

 

[AMc]

My understanding was that error correction information is sent as part of the digital data stream so that the decoder at the other end can work out if there was data missing and if so make an educated guess at what it should have been. Avoiding the sharp screeching noise and blocks in picture that you get when there is serious loss of signal. Only non real time packet based systems can ask for the data again if it didn't arrive intact.

Then I googled "digital error correction" and discovered another bodged cable/connection standard

This thread suggests there is limited error correction for small interuptions
http://arstechnica.com/civis/viewtopic.php?f=6&t=275120&p=6271817
This article by a high end cable manufacturer points out all the problems with HDMI per se and the bit on "Skin Effect" refreshed my memory of why Cat6 data cables need to be routed really carefully. It also points out the problems with digital data transmission get worse as the distances increase.
http://www.bluejeanscable.com/articles/whats-the-matter-with-hdmi.htm

I also didn't realise that a 1080p video and sound signal contained more information that a fully loaded Cat5 data cable.

God, how geeky have I become?

 

[Penners]

Interesting - particularly FF's point about a digital signal being (my own word) "undegradeable".

We have a Humax Freesat receiver and a Sky receiver (we're about to ditch the latter). The Freesat box is connected to the TV via an HDMI cable and the Sky one via SCART. When I asked a TV engineer why the Freesat picture on the TV is so much sharper and cleaner than the Sky one, he said it was because of the difference between HDMI and SCART connections.

Was he talking rubbish? If a digital signal can't be degraded, then I'd be interested to know what is causing this significant variation in picture quality. I should add that I'm talking about a standard definition image in both cases.

 

[MdB]

Was he talking rubbish? If a digital signal can't be degraded, then I'd be interested to know what is causing this significant variation in picture quality.

SCART is analogue....

 

[Flyfisher]

My understanding was that error correction information is sent as part of the digital data stream so that the decoder at the other end can work out if there was data missing and if so make an educated guess at what it should have been. Avoiding the sharp screeching noise and blocks in picture that you get when there is serious loss of signal. Only non real time packet based systems can ask for the data again if it didn't arrive intact.

Error correction is another whole 'layer' of digital communication systems. Are you familiar with http://en.wikipedia.org/wiki/OSI_model?

To continue (very roughly) the morse analogy:

Level 1 - the basic transmission medium; could be telegraph wires, could be radio transmission, could be optical fibre - anything that enables some sort of signal to be sent from one place to another.

Level 2 - the basic signalling scheme - with morse this is defined by dots, dashes, and intervals. For old-style RS232 serial data it was +/-12 volts on a single wire. For optical signalling it could be the light source being on or off.

Level 3 - Addressing. Not really necessary with a point-to-point wired link, but is essential for networks such as the postal service or, of course, the internet, to ensure that the data sent by Layer 2 can be routed to the intended receiver(s). In a broadcast environment, this layer could include encryption so that although anyone can receive the data, only certain receivers can decode it.

Level 4 - Correction. Optionally provides a mechanism for the receiver to verify that the received data is correct. There are many schemes for this, from simple parity bits and various Forward Error Correction mechanisms that involve sending additional data that allows the receiver to detect and correct any transmission errors. A simple example would be the use of the phonetic alphabet on a noisy telephone link - additional information is sent to ensure the basic data gets through.

Level 5 - Verification. Optionally provides a reverse communication channel for the receiver to verify correct reception (based on the error detection/correction mechanism of level 4) or to request the re-transmission of the data if error correction was not possible.

Etc, etc.

It all sounds complicated, and in absolute terms it is, but because the interfaces between each level can be so tightly defined their internal complexity is hidden away, which makes it practical for the huge variety of different devices to be connected together easily and reliably without having to worry about what's actually happening to get, say, a picture on your TV from a DVD or to allow you to post messages on PPUK from anywhere in the world with no transmission errors, despite the huge numbers of data transmission links and data errors encountered in the process.

Sadly, the reliability of even domestic transmission technology is such that we can't even blame it for our occasional typing errors. :wink:

God, how geeky have I become?

Funny you shoudl say that.

 

[AMc]

Light & sound is analogue, the cameras and microphones capture that and then TV network ENCODE that audio and view into a digital signal that they bounce off the satellite.

The Sky box DECODES the digital signal into an analogue video and audio signal and sends it to the TV which then ENCODES it back to a digital image, resizes and processes it to suit the pixel resolution of the screen then finally DECODES it back to the pixels in the screen.
It's the decoding/re-encoding/scaling that is damaging the picture quality not the method of moving the signal from one place to the other.

In contrast the Freesat box receives a digital signal and does a minimal amount of data manipulation to send the original digital stream of video and audio to the TV. The TV then DECODES the signal once at the right size for the TV panel.

The point made in one of those links is that digital signals are not all or nothing...here is the relevant bit.

We tend to assume, when thinking about wire, that when we apply a signal to one end of a wire, it arrives instantaneously at the other end of that wire, unaltered. If you've ever spent any time studying basic DC circuit theory, that's exactly the assumption you're accustomed to making. That assumption works pretty well if we're talking about low-frequency signals and modest distances, but wire and electricity behave in strange and counterintuitive ways over distance, and at high frequencies. Nothing in this universe--not even light--travels instantaneously from point to point, and when we apply a voltage to a wire, we start a wave of energy propagating down that wire which takes time to get where it's going, and which arrives in a different condition from that in which it left. This isn't important if you're turning on a reading lamp, but it's very important in high-speed digital signaling. There are a few considerations that start to cause real trouble:

1. Time: electricity doesn't travel instantaneously. It travels at something approaching the speed of light, and exactly how fast it travels depends upon the insulating material surrounding the wire. As the composition and density of that insulation changes from point to point along the wire, the speed of travel changes.
2. Resistance: electricity burns up in wire and turns into heat.
3. Skin effect: higher frequencies travel primarily on the outside of a wire, while lower frequencies use more of the wire's depth; this means that higher frequencies face more resistance, and are burned up more rapidly, than lower frequencies.
4. Capacitance: some of the energy of the signal gets stored in the wire by a principle known as "capacitance," rather than being delivered immediately to the destination. This smears out the signal relative to time, making changes in voltage appear less sudden at the far end of the wire than they were at the source. This phenomenon is frequency-dependent, with higher frequencies being more strongly affected.
5. Impedance: if the characteristic impedance of the cable doesn't match the impedance of the source and load circuits, the impedance mismatch will cause portions of the signal to be reflected back and forth in the cable. The same is true for variations in impedance from point to point within the cable.
6. Crosstalk: when signals are run in parallel over a distance, the signal in one wire will induce a similar signal in another, causing interference.
7. Inductance: just as capacitance smears out changes in voltage, inductance--the relationship between a current flow and an induced electromagnetic field around that flow--smears out changes in the rate of current flow over time.