The Unsung Heroes of Radio

Aerials, the unsung heroes of radio!

They may not be glamorous or sexy but your aerial is arguably the most important part of any radio system. It is the link between the station transmitter and your car radio and without it the best radio receiver in the world is going to be silent.

This is particularly true for modern DAB receivers. Digital radio is still broadcast on the FM waveband but the signal is now just a string of 1s and 0s instead of a modulated analogue signal. This transmission method means more stations, more data, better sound and clarity. There has been an explosion of content providers keen to use this digital media rather like we saw when digital TV started.

Despite the many advantages of digital transmission, there is one major drawback, the fact that it is either fully available or not at all. That is to say that if reception quality falls then the signal completely disappears. With an analogue FM signal if the signal strength dipped then all that happened was a slight interference or a drop to mono, DAB on the other hand will ‘bubble’ and disappear, usually just when things are interesting!

So let’s concentrate on DAB aerials as they are crucial to good reception. Most DAB radios are sold with an in windscreen aerial.

screen-aerial

Let me say now that these are the least desirable type. They work but at a very low gain which means that in weaker signal conditions they will fail. Of course, a lot of modern cars have no external aerial and you may not wish to install one so these stick on aerials are your only option. Some are better than others and at Car and Home Stereo I have tested as many as I can find. The one I use is the most successful one to date offering reasonable reception under most conditions. This is not to say it is faultless and it still suffers from directional issues which are to say a station can be clear when travelling to work but poor in the opposite direction.

For best reception there is nothing better than an external aerial. Since DAB radio is broadcast on the FM waveband it is perfectly possible to use a standard aerial as fitted to the roof of some Fords and wing mount on Land Rover Defenders. All that is needed is a modulator to separate the two signals.

plastic-bag

These can offer up to 10 dB of gain for both FM and DAB which means a great reception for both.

Unfortunately the modulator cannot be used with existing amplified aerials as fitted to many cars.

silver-aerial-car

These vehicle aerials strip off the higher frequency signals before sending to the radio so no DAB. In these cases I always prefer to fit a replacement combined FM/DAB aerial.

white-car-aerial

These can again offer up to 10dB of gain and of course suffer no directional issues. If your car has navigation then there is a version of this aerial that also contains a GPS receiver. The mast is removable and the look of the car is unchanged. I have often fitted this aerial to cars with no external mast like the Volkswagen T5 and the reception is dramatically improved.

As I said at the start, aerials are not glamorous but getting it right will mean trouble free reception and less annoying drop outs.

 

Call Tim on 01625 432707 if you wish to discuss options to improve your radio enjoyment.

 

Simon Says? Speakers Please!

For this instalment let’s look at speaker installation. The speaker is the last piece of hardware between your music and your ears and as such has an awful lot to do with the sound you hear.

The science behind the speaker is extremely simple; pass an electric current through a wire that sits inside a magnetic field and the wire experiences a force, vary that current and you vary the force. Of course this demonstration produces no sound but if we attach the wire (or coil) to a diaphragm (or cone) we have the nucleus of a working speaker. The electronics in the amplifier produce the varying electrical current and the speaker responds, creating the highly complex vibrations in the air that we hear as music.

The above description is of course highly simplified and in reality there are many more aspects to speaker design. We have to consider the weight of the moving parts, the resistance to movement within the materials themselves, the linearity of the magnetic field, the quality of the coil wire, the damping to prevent uncontrolled excursion, stability of the frame and so on and so on! Fortunately all of these considerations are engineering problems and this means that better engineering will lead to a better product.

pic-of-rainbow-tweeter

When Mr. Ford or Mr. Audi or even Mr. Porsche are told that they have to put speakers in their cars their first consideration is not about quality even when they enlist the help of respected Hi-Fi companies. Their overriding concern is one of reliability. A blown speaker is a warrantee issue and that costs money. The trouble is that a speaker that can survive heavy metal hard core country rap at full volume has to be made super resilient. This speaker is not going to be able to respond to the subtle nuances of any quality musical performance.

pic-of-sam-bad-sound-face

At Car and Home Stereo we are always going to install a high quality speaker, carefully selected to match the vehicle and musical tastes of the customer. This is where our installation skills are needed. The average car door is a challenging place for a speaker. It is a steel box that is often wet inside, can be freezing one day and very hot the next. There are moving parts within it and it is subject to a large amount of vibration and noise. Let’s look at a typical installation addressing each point.

First of all we carefully remove the inner trim making sure that all clips and seals are retained. After this the next job is to treat the metal skin with sound deadening material which will absorb road noise and any vibrations within the door.

dsc_0002

Particular attention is paid to directly behind the speaker as this will absorb the sound generated by the back of the cone and prevent reflection back into the door panel.

Once the outer skin has been treated we apply a foam barrier to the inner skin. This forms a watertight seal and acts as a thermal and acoustic barrier. This keeps the car warmer in winter, cooler in summer and again reduces road noise. The difference these treatments make to a car is astonishing.

dsc_0003

Now we come to installing the speaker. The factory units are often built to fit so we must make panels and collars to allow a perfect fit to the door.

dsc_0004

It is very important that no moisture gaps are left as it may come as a surprise to know that doors are designed to let rain flow through them. Any gaps could lead to a wet floor so we make sure everything is sealed with high quality silicone, both the collar and the speaker, this also ensures no air gaps to compromise the speaker performance.

dsc_0006

Quite a lot of work but absolutely worth it. These Audison APK speakers sound great anyway but by treating the door they are at least 30% better.

If you would like to know more about how we can improve the sound in your car please call Tim on 01625 432707.

Cutting Edge! with JL Audio

Today let’s look at the range of fantastic high performance products from JL Audio.

Formed in 1975, JL Audio are based in Florida USA and from the very start, their passion has always been to produce the best possible products. Originally they concentrated on sub-woofers and they quickly earned an enviable reputation for amazing power and performance. More recently JL Audio have expanded their range to include speakers and amplifiers with the emphasis once again firmly on quality and performance.

_dsc0055

It’s true to say that the JL Audio range of subs has something for everyone. From small, discreet custom enclosures to high output monsters to true Hi-Fi quality audiophile drivers. The engineering expertise at JL Audio means that even their least expensive sub still sounds amazing and will work in a relatively small enclosure.

Every in car system will benefit from the installation of the dedicated bass speaker and at Car and Home Stereo we will make sure that it is fitted and set up correctly.

 

 

_dsc0047

Of course a sub-woofer always needs an amplifier and so the logical step for JL Audio was to produce their own range. Car and Home Stereo is proud to be a JL Audio Signature dealer which means we carry a wide range of products. The XD range of amplifiers is a particular favourite of mine. They only take up a small amount of space but deliver an amazing performance! From the compact XD 200.2 to the immensely powerful XD 1000.1 they offer a level of flexibility and performance unparalleled to anything else.

Never a company to stand still, JL Audio have just upped their game and released a new range of amplifiers designated the RD series.

 

_dsc0052

These units are extremely good value for money and sound amazing as they are based on JL Audio’s NexD D class technology. Multiple input configurations are available making for pretty much universal compatibility while the small footprint means installation is straight forward.

_dsc0048

JL Audio speakers are some of the best around. Even the entry level TR series have a detail and clarity many other more expensive speakers cannot compete with. Taking a step up to the C2 series and we are well on the way to a true Hi-Fi performance. Where space is tight the C2 400 (a 10cm speaker) punches far above its weight for low frequency. This has become my first choice for the Land Rover Defender and is more than capable of overcoming the road noise while still producing a full range performance.

One speaker range stands out though, the C5. This speaker range has a natural and transparent sound that is simply breathtaking. OK they are not cheap but that is not the point, where high fidelity is the goal you have to go a long way to beat this speaker. The tweeter alone is one of the smoothest speakers I have heard with vocal and piano pieces a joy to experience.

And of course there are many more products in the JL Audio line up. There are processors that allow seamless integration with factory standard audio systems. These units can repair the poor performance of the standard head units found in BMW, Audi,  VW and others that can not be changed meaning you do not have to put up with the stock audio.

There is also a range of very high performance marine speakers used on the like of Sunseeker power boats. However at Car and Home Stereo we are land locked and there has never been a big demand for these here!

The most important point is that, with JL Audio, we have a range of products that can suit any application and any performance requirement. We have the experience and resources to make sure we offer and install the best possible sound at any budget.

 

Give Tim a call to discuss your requirements or, better still, call in to the shop in Macclesfield for a coffee and a chat.

Don’t Sacrifice Quality Today featuring Bose

Here at Car & Home Stereo, we don’t just stock speakers we also have a great variety of Bose accessories.

_dsc0094

_dsc0107

We don’t think you should have to sacrifice quality if you don’t have a high tech set up so we have some incredible Bose headphones in store. It is an ideal birthday or Christmas present for just about anyone.

 

Pop into Car & Home Stereo on Sunderland Street for more information.