We do not recommend any specific Brands or Models. However, we can give a few hints on what to look for when selecting your Amplifier/Receiver. Amplifier requirement figures (Watts) are intended only as a guide. As a general rule buy the most powerful amplifier that you can afford within the specified range and use it with great care. It is easier to damage the loudspeaker with a small amplifier driven into distortion using too much volume with bass and treble boost, than with a large amplifier which has plenty of power in reserve. If in doubt, ask your dealer.

Our loudspeakers use carefully graded OFC internal wiring and high quality components. The cable between the amplifier and the inputs on your speakers can be a potential limitation in the system. As a general rule, any high quality multi strand or solid conductor will give good results. Speaker cable can be a very personal choice, for best results avoid very thin cables or "bell wire" as they can strangle the signals that your amplifier is sending to your speakers.

There are many good brands of speaker cable on the market. Refer to Hi-fi magazine tests and dealer recommendations before you decide on the best cable for your system and budget. A suggested budget for cable is 5% of the total cost of your speakers per metre of cable used.

Bi-Wiring is the use of two pairs of cables between each amplifier channel and the associated loudspeaker. The crossover in a "Bi-Wireable" speaker has two separate earth and or signal paths. By keeping these paths separate all the way back to the amplifier retrieval of fine detail can be improved.

Simply remove the links connecting both positive and negative binding posts together, and run two identical lengths of cable to each speaker from the amplifier output terminals. Special "Bi-Wire" cable is available for a tidier installation.

Bi-Amping is similar in principle to Bi-Wiring but uses a separate amplifier for each set of terminals. This can give even greater benefits than Bi-Wiring as the smearing of the delicate higher frequency information due to masking from the bass information can be significantly reduced. It is important that the amplifiers used are of the same type, or have matched gains.

Speakers that can be "Bi-Wired" can generally be "Bi-Amped" as the crossover is essentially two or more separate circuits isolated from one another (when the links are removed).

Modern home theatre receivers have an LFE (low frequency effects) channel that provides only low frequency signals for an active subwoofer.

If your receiver/amplifier has a subwoofer output, use a commercially available subwoofer or RCA cable to connect this output to the low level input on your subwoofer. You only need to connect one input on the subwoofer as it is a Mono device.

Some early home theatre Receivers/Hi-Fi Amplifiers do not have a low level subwoofer output. The only means of output is from the main left and right speaker channels. The following models of subwoofers feature "High Level" inputs for this purpose, PSW4000 and PSW5000. Simply connect the subwoofer between your amplifier and speaker system using the "High Level" inputs from the amplifier and the "High level" outputs to your speakers, to enjoy extended low frequency sound for music and home theatre.

(Do not connect both "high level" & "low level" inputs to your amplifier, as damage may result).

Note : Other Subwoofer models (PSW1000.2, PSW2500, PSW3500) are supplied with a converter to connect speaker cable.

If the upgrade means replacing the speakers completely then yes! However, if it's the internal components that you want to change then no! Why? Well, when we design a loudspeaker all factors are taken into account, the vocals, bass delivery and overall sonics. This takes qualified engineers a long time to do. If you were to change any element of the speaker by replacing the factory fitted components, then the response could change dramatically, this could actually make the speakers sound worse.

Please note that all service related issues should initially be taken up with the place of purchase. Contact details for authorised KEF retailers can be found on our dealer section of this site. Should you experience problems with a particular retailer then please contact the authorised distributor for your country.

It is our policy to maintain a healthy back-up of Reference Series parts for a period up to ten years. All other models are supported up to eight years from last date of production. In some cases, stocks of parts can become exhausted before our policy date, due to supplier problems, in these rare cases we will do our best to offer an alternative. For those speakers outside of the serviceable date, it is unlikely that we will be able to support with any spare parts, however it is worthwhile contacting your nearest local distributor who may have parts in stock that are no longer available from the factory.