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HINTS & TIPS HE98

 

SCART SWITCHER

Name: Gideon James
Kit: Sony KP41DS1U, Toshiba SD-210E, B-Tech switch box
Problem: Gideon's Sony TV set has three sockets, but only one of which is RGB compatible. He has a digibox, a DVD player and a games console all fighting for the same RGB SCART socket. While his manual switching box works fine and automatically switches the TV into widescreen mode when necessary, he would like a more 21st Century solution to the problem. Gideon wants a switch box with at least two RGB compliant SCART sockets that will support automatic widescreen switching and will automatically detect which device (DVD or Digibox) is in use, or at least have a remote control for this last function. Does such a thing exist?
 

EXPERT REPLY

We can put a man on the moon and technological marvels like Furby are freely available, but the ability to construct televisions with enough input sockets still seems to elude the consumer electronics industry. As Gideon has discovered you can get SCART switchers, you can even get ones that can handle wide screen switching (see Getting Started) and RGB signals, but you can't get one that switches two or three RGB sources and widescreen signals automatically, or by remote control. At least, if there is one it's well hidden…

 

Well, that's not strictly true, in fact there is such a beast, it's called the Quattro+ and it's made by B-Tech, which also makes the manual switcher.  Gideon has been using. He's also tried the Amstrad DRX100, but neither of them worked for him. It turns out that the Quattro+ has a few compatibility problems with widescreen switching, notably with Philips TVs, and as Gideon has discovered, with some Sony models as well. We spoke to B-Tech, which is based in South London, and a spokesman told us they are aware of the problem and are working on it and has promised to get back to us if they manage to crack it. We'll keep you posted. In the meantime, if anyone else has any suggestions…

 

 

CENTRE SPEAKER

Name: Guy Dewdney
Kit: Pioneer NS-DV55 system Eltax Silverstone fronts, Mordaunt Short 905C centre speaker
Problem: Guy wasn't happy with the sound of the speakers supplied with the NS-DV55, to an Eltax/Mordaunt Short mix. But, when Guy runs the speaker set-up, he gets a different sound in the centre from the rest of the speakers. Is there anything he can do to improve this, without buying M.S. fronts and rears? There is no tone control for each individual speaker, just level and overall bass and treble. Also, what is the best way of isolating a pair of floor-standing speaker from a laminate floor (on top of concrete)? He has read that he should isolate them to reduce the bass from travelling through the floor. Is this correct?

EXPERT REPLY

In an ideal world the centre channel speaker would be identical to the front stereo pair. Back in the real world, the centre channel speaker has to be located above or below to the centre line of the screen, which puts major constraints on size and shape, it also has to be magnetically shielded, to prevent colour 'staining' on the screen. All of which means that centre channel speakers inevitably end up with different tonal characteristics to their right and left channel partners, even if they're part of a 'matched' set.

 

However more often than not the biggest impact on centre channel sound is not the design of the speaker, but how and where it's mounted. Placing a centre channel speaker in direct contact with the TV cabinet – i.e. on top – is bound to cause problems. TV cabinets are big plastic boxes, mostly full of air, that resonate at the drop of a hat. If that's the only place Guy's speaker can go he should try isolating it from the cabinet, something as simple as Blu-Tack will work. Better still Guy should find a way of mounting the speaker well away from the TV or any resonant surface, and run through the surround setup again (see Quick Tip).

 

As far as Guy's query about laminate flooring is concerned, he should try a set of Linn 'Skeets' which are designed specifically for that purpose. In addition to providing a high degree of isolation they also protect the floor.

 

QUICK TIP

Most surround sound amplifiers have switchable centre channel modes. Phantom creates a pseudo centre channel from the right and left stereo channels on systems with no centre speaker. Wide is for larger centre speakers and it allows through the full (wideband) frequency range but it can sound a bit confused on smaller speakers. Normal is the best setting for most compact centre speakers, with bass and lower mid-range diverted to the right and left channels.

 

 

SYSTEM OR SEPERATES?
Name: Hywel Jones
Kit: Wharfedale DVD-750s, Hywel's first house
Problem: Hywel is on the first rung of the property ladder and wants a home cinema surround sound system. So far, all he has is a Wharfedale DVD player, and wants good recommendations for widescreen TV, amp and speakers to go with it. Hywel has not decided whether to buy a Bose Lifestyle 25 system or build a system out of separates. He has also seen the Bose Acoustimass 15 speaker system and wonders if there are any other alternatives on the market that would cost less and provide just as good a sound?

EXPERT REPLY

It would have been helpful to know more about how much Hywell has to spend, the size and layout of his rooms etc., so we can't make any specific recommendations but we can still talk about general principles. When it comes to widescreen TVs the best advice is to buy the biggest screen you can afford and comfortably accommodate. Since Hywell has opted for external surround, he can save himself a few bob and shortlist models with more modest sound systems.

 

The package system approach has a lot going for it, they're usually very convenient, you can be fairly sure that all of the bits will work together, setup is usually quick and easy and the highly integrated approach usually means only having to contend with one remote handset. The Bose Lifestyle 25 is a slick, eye-catching design and in the right environment – relatively small rooms – it can perform well. The downside of a package like this, though, is limited opportunity for upgrading. The speakers and compact main unit are all designed to work with one another so if Hywell wanted to change the CD deck or use a more powerful amplifier, it would be mean scrapping large parts of the system. It appears that Hywell is prepared to spend in excess of £2000 on the audio side of things, we think he'd be better off going the separates route, allocating between 40 and 60 percent of his budget on the speakers.

 

 

ROOM SIZE
Name: John Hutton
Kit: N/A
Problem: John's room isn't that big (2.36m x 3m) and he wonders if this is too small for a home cinema system. He would like to go for a widescreen TV and separate surround sound system, but will this be overkill in such a small room?

EXPERT REPLY

John can take comfort from the fact that no room is too small for home cinema, we've seen and heard some very pleasing systems in rooms not much larger than broom cupboards… Nevertheless, the size, layout and whatever else is in the room will put constraints on the equipment. John should start with the TV; as a very general rule of thumb viewing distance should be between 3 to 5 times screen height on a 16:9 display. In theory, with the TV hard up against one wall and John sitting at the other end of the room he could go up to a 40-inch screen but that would probably be a bit overwhelming (very impressive though…). A 28-inch screen is probably the best bet in this situation but he should avoid getting one any smaller as they tend to loose their impact and look horribly small, to the point where you're better off with a 4:3 inch model.

 

Package AV systems -- preferably one that allows for a certain amount of upgrading -- are ideal for smaller rooms. John should shortlist ones with a decent sub woofer, to make up for the front and rear speakers, which on most package systems tend to be fairly compact. 

 

 

NETWORKED DVD?
Name: Dave Shrimpton
Kit: Sony HT-K215 home theatre system, Pace Sky digibox, Sony DVD-S536 player, Toshiba 3377db television, Panasonic NV-HD6620B video player.
Problem: Dave has both the digibox and video daisy-chained and Scarted to the TV, the DVD player is linked via the S-Video connection at the TV and the home theatre system. The RF Aerial is also daisy-chained through the video, digibox and TV and ends up in an amplified splitter that feeds five portable TVs throughout the house. Dave wonders if it possible to link the DVD somehow to the splitter box in order to push the signal throughout the house, without compromising sound or picture elsewhere?

EXPERT REPLY

Theoretically it is possible but the kit needed to do it – without any significant reduction in picture or sound quality -- would probably come to more than the cost of putting a DVD player in every room… It's not difficult to re-modulate the video and audio signals coming out of the DVD player onto an RF carrier that could be sent down the aerial feed but that would involve a big drop in picture quality, and lo-fi mono sound.  Similarly, devices like wireless video senders introduce noise on both the video and audio signals and even though some models work in stereo, there will be a noticeable loss of bass and treble information.

 

The point is, the AV signals that emerge from the back of a DVD player are in pristine condition and any additional processing -- that would be involved in squirting them down an aerial cable – will degrade the signal.

 

The only way to distribute AV signals without serious loss is to keep them in their native formats and use a distribution amplifier to send them separately down high quality shielded cables but even that can be difficult to do without loosing quality. Composite video signals and line-level stereo can travel several tens of metres without too many problems; for S-Video signals the safe distance is 15 to 20 metres, RGB video struggles over distances of more than 5 or so metres. Amplifiers or 'boosters' can be used to lengthen cable runs but they will introduce yet more noise.

 

 

LP TO PC
Name: Trevor Baynes
Kit: Sanyo hi-fi system (with broken CD player)
Problem: Trevor is running out of space in his house; he has hundreds of videos and nearly 600 vinyl LPs. He wants to convert his LPs to CD-R and his VHS tapes to Video CD. Trevor has been told that there are computer programs that will do these tasks, but would like to know what is required and what DVD player will play them on.

 

EXPERT REPLY

There are indeed plenty of programs that can record audio and video onto CD-R discs but the first thing to sort out is the hardware. To do this kind of job properly the PC in question needs to be a reasonably recent Pentium/Pentium class machine, preferably running at 233MHz or faster with at least 128Mb RAM, Windows 98/ME and a CD-writer and video capture card, or USB capture module for video recording. He will also need a lead (3.5mm stereo minijack to phono) to connect the 'line output' from his hi-fi to the audio input on his PC.

 

Programs are available that will record analogue audio from LPs or tape cassettes as *.wav files, and then convert them to CD-A tracks which can be 'burnt' onto a CD-R disc, however they tend to be quite advanced. Fortunately there are plenty of freeware and shareware utilities that do the job just as well. Trevor can get his feet wet with Polderbits audio recorder from http://www.polderbits.com/) and MP3 CD Burner from http://www.cdburner.com/.

 

With a little practice Trevor should also be able to make his own Video CDs (see Quick Tip) from VHS recordings and these will play on most DVD players. A good place to start would be a hardware encoder and editing package, like Pinnacle's Studio 10 (www.pinnaclesys.com), which costs around £200. The alternative is a software MPEG1 encoder, like Tsunami

(http://www.tmpgenc.com/e_main.html), it's freeware and capable of good results. It is slower than a hardware encoder moreover it is quite sophisticated and best suited to advanced users.

 

QUICK TIP

Video CDs that will play on most DVD players are recorded using MPEG 1 encoding. This is a highly data compression system that can fit around an hour's worth of video and sound on a standard 650Mb CD-R/RW disc. Picture quality is similar to standard VHS though much depends on the capabilities of the 'authoring' software and hardware, how carefully it has been set up and the condition of the original recording.

 

 

IN OR OUT?
Name: James Culver
Kit: None as yet
Problem: James wants to spend £2,000 on a TV and home cinema system. He has already settled on a speaker system, but is unsure whether to go for a 32-inch Sony model or a similar sized Thomson set that has a built in DVD player. He wonders which is the best for picture, connectivity, options etc.

EXPERT REPLY

This question did the rounds twenty years ago when TVs started appearing with built-in VCRs and the same broad arguments apply. On paper it all looks very convenient, it saves space, one remote handset controls everything, installation and setup should be a lot simpler and there should be performance gains because the TV and video deck – in this case a DVD player – are designed to work together and in the same box. (In practice there are no discernible differences).

 

On the minus side there's the issue of reliability and the consequences of either the TV or video deck breaking down, though these days the technology is a lot more reliable and there's less to go wrong or wear out in a DVD player. However, the main argument against built-in video decks is a lack of flexibility. The average working life of a TV is around eight years but James will probably want to replace or upgrade his DVD to a recordable unit perhaps, DVD-Audio or SACD long before that. Having the player in the TV usually makes it harder to connect to other devices, and what if he wants to play DVDs on another TV in another room? Portable combi TV/DVDs, like combi VCRs do make sense but we've yet to be convinced about larger screen models. 

 

 

REAL RESOLUTION?

Name: David Silverman
Kit: N/A
Problem: Because of price reductions, David is unsure whether to choose a plasma screen instead of a large CRT set for his new home. However, he is confused as to what the difference between 'true' and 'compatible' resolution really is. David also wonders if there is any difference in quality between US and UK machines, as the US samples seem so much cheaper.

EXPERT REPLY

Screen resolution is basically measure of how much fine detail a display can reproduce. On any colour video display that is determined by the number of visible picture elements or 'pixels' that go to make up the display and this is known as 'native' or true resolution. On 16 x 9 panels this is typically 852 x 480, 1024 x 1024, 1280 x 1024 or 1365 x 768 pixels (see Quick Tip).

 

'Compatible Resolution' was introduced in the US to get around the problem of an apparent mis-match when the source or delivery format has a resolution that's higher than that of the screen, as would be the case with the American high-definition TV (HDTV) system. Panels with HDTV compatible resolution can display the pictures though for obvious reasons the images contain no more detail than the highest native resolution allows.

 

Plasma screens are cheaper in the US and the actual panels are no different to the ones we can buy here – it looks a lot like the old dollar to pound conversion trick. If David tried to import one he would almost certainly loose out heavily on the deal by the time freight charges, import duty and VAT were added on to the final cost.

 

QUICK TIP

The number of pixels in a plasma screen is largely determined by the size of the panel, in other words the larger the screen the more pixels are needed to avoid the image looking coarse. Aspect ratio also has a big influence, both on the number of pixels, and their shape. The pixels on 4:3 displays tend to be almost square whilst those on 16:9 panels are more rectangular, to take account of the screen's extra width.

 

 

AMPLIFIER CHOICE?

Name: James Lewis
Kit: Sony 25" Nicam TV, unnamed Dolby Pro-Logic system
Problem: James plans to add Dolby Digital/dts 7.1 channel sound to his existing system and wonders what amplifier to buy. He is planning to add a big-screen TV to the system. Which leads to his second question; is it better to buy a TV with a separate decoder or an integrated digital TV?

EXPERT REPLY

It's impossible for us to recommend products without knowing how much James is prepared to spend, both on the device in question and whatever it is going to be connected to (in this case the speakers), and a general idea of the sort of environment it is going to be used in (room size, shape, layout furnishings etc.). James is going to have get back to us, or better still, get out there and look and listen to a few systems for himself.

 

James' second question is more straightforward and it comes back to the old issue of convenience versus flexibility and choice. Having things like satellite/terrestrial TV decoders built into the telly cabinet can be handy, it's one less box and one less remote handset for a start, but it makes upgrading difficult. The software used in some early integrated digital TVs cannot be easily updated and who knows what's still to come? What happens if the decoder inside the TV keels over and dies? Will you still be able to watch TV, or will the whole shooting match have to be carted back to the workshop? Whenever possible, in all almost things to do with a fast moving technology like home cinema, separate is usually best…  

 

 

CENTRE SOUND
Name: Adam Hornberger
Kit: Pioneer DV-636D DVD player, Yamaha DSP-A492 amplifier.
Problem: While playing the DVD, Adam can still hear through the sound of the TV through the centre speaker, but when running the VCR through the amp, it does not happen. He has tried disconnecting the VCR source from the amp but this does not solve the problem. Adam is planning to buy a Denon 3802 amp, but wonders if he will still get the same problem?

EXPERT REPLY

So-called audio 'bleed through' from alternate sound sources or channels is not at all uncommon, unfortunately there's no single cause and it can sometimes be a real swine to track down. The first thing Adam should do – and it sounds as though he's already made a start – is to try a process of elimination.

 

There are only two places where TV sound could be coming from in Adam's system, the TV itself, and the VCR, unless he also has a digital satellite or terrestrial decoder, in which case they will have to be dealt with separately. If it only happens when the VCR (or TV digibox) is connected – either to the TV or the amplifier – then it's probably a lead problem. He should try upgrading to better quality cables, making sure they're routed well away from any other signal carrying leads, and it's worth trying an earth connection to the amplifier case. If the problem persists when the VCR or digibox is disconnected (and that includes the aerial bypass leads) then there may be a problem with the TV, but without knowing the make or model we cant' say for sure if it's a design problem or a fault. 

 

 

GETTING STARTED – Widescreen Switching

When widescreen TVs first appeared in the early 1990s users had to manually select 16:9 mode when watching letterboxed movies on tape and occasionally shown on TV. These days there are many more sources of widescreen pictures – DVD and digital satellite and terrestrial TV to name but two – and most recent widescreen TVs automatically switch to the most appropriate display mode.

 

The most widely used system is Widescreen Switching (WSS). In the case of broadcast TV a digital signal or 'flag' is inserted into an unseen picture line (line 23). This is picked up by the TV, which re-configures the picture so that it fills the 16:9 display; the same picture, seen on a 4:3 TV, will appear letterboxed, with black bars at the top and bottom of the screen.

 

In the case of widescreen movies on DVDs, the player's setup menu has the option to display pictures in 16:9/widescreen, 4:3 or pan and scan. When set to 16:9 the player 'anamorphically' compresses the widescreen image, so that on a 4:3 TV everything looks tall and squashed. The player generates a switching signal on pin 8 on the SCART lead, which instructs the TV to stretch the picture horizontally so that it expands into the widescreen display.

 

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Ó R. Maybury 2001, 0110

 

 

HOME ENTERTAINMENT                                                        TEXT 2…01

 

HINTS & TIPS HE98

 

GETTING STARTED

 

VIDEO SENDERS

Video distribution is one of the home entertainment black arts and surprisingly difficult to accomplish, without compromising picture and sound quality, or spending a small fortune and causing much disruption laying cables. The simplest and cheapest method is still the video sender, where the audio and video signals from a DVD player or VCR are modulated onto an RF carrier wave and re-transmitted, either as radio waves, or down a coaxial cable. Early senders simply re-transmitted the signals on the UHF band, so they can be picked up on a spare TV channel.  This method is actually illegal and predictably causes no end of problems with interference. (Urban legend has it that one couple was caught using one after neighbours complained about picking up their smutty home made videos…). Legitimate senders use a much higher frequency band and the sign is picked up on a purpose-designed receiver unit, that plugs into the TV's aerial or AV sockets. The processing required to send video and sound signals inevitably leads to some loss of quality and an increase in noise levels, nevertheless, senders are a quick and easy way of moving AV signals around the house, the range is typically 20 to 50 metres (indoors) and there's no problems with cables.

 

---end---

 

Ó R. Maybury 2001, 2210

 

 

 



 

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