We have aTechnics SEHD560 about 2 year old hardly used but on the odd occasion when required and not at full blast the sound cuts out also the decibel meter works in reverse we have had it back to the suppliers on numerous occasions to find no fault I was told there is a safety device to protect the speakers but this can be removed prior to throwing this as new 4hundred quid out fit in the bin can you help
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Speaker requirements are likely to be 8 ohm, most modern hi-fi speakers are. A few low-fi systems have used special high impedance speakers and the old hi-fi standard for valve amplifiers was 15 ohm and 3 ohm or lower has been used in televisions a lot.
4 ohm speakers are commonly used where a higher power output is desired at the cost of some quality of sound reproduction but depending on how the sound is listened to can soon overload some amplifiers primarily designed for 8 ohm as it will try and deliver more power into the lower impedance speakers and perhaps exceed the rating.
8 ohms is a safer choice. The lower the wattage rating of the speakers the more efficiently they tend to be able to reproduce sound at low volume levels so for background music in a small domestic environment the average power requirement will be in the order of half a watt so even with a high powered amplifier the volume would rarely be turned up above 1 - 2 on the typical scale of 10 and ten watt speakers would be more than adequate. It is unfortunate that it is almost impossible to obtain quality speakers rated at such an unfashionably low power rating.
With the stiffer cones of a higher power rated speakers the volume has to be turned higher before the speakers become efficient and listening at low levels can be difficult. In a domestic environment a 50 watt rating is perhaps the best compromise as if there are neighbours to consider a ten watt average power output will be sufficient even if the amplifier is capable of higher powers. Just don't turn the volume up more than necessary.
The greater the power rating the more power will be required for efficient reproduction. For electrical and mechanical safety of the speakers the rating should exceed the maximum output of the amplifier but listening at low levels with quality of sound can become virtually impossible.
Real low bass is mostly vibration. Anything that has a "mega bass" 'enancement' is cutting corners to make up for bass-reproduction shortcomings. Speakers measuring 2-5/8' have no business reproducing real bass. Blown speakers would be silent. Torn cones from excessive volume might sound like unwanted vibration. Your vibration might be a resonance of the unit's own housing, mounting hardware or something nearby. Try moving it to another location.
These units are not economically repairable. If you like it and you think it's broken you might snag a whole new on on eBay with wise bidding.
All the electronic parts you can see inside the speaker (usually capacitors, coils and resistors) are responsible for breaking the full audio band (bass - middle - treble) in parts (2 for your case) and feed each part to the appropriate speaker. By that I mean that you must not use your speaker without the cross-over (this is the name of the circuit) since this can harm your speakers. The sound from a speaker without crossover will be terrible for your ears too. Eventhually you can try to connect your tweeterat the amplifier's output leads, assuming that the volume level will be very low. Using this connection you can just check if the tweeter is working ok or not, so you can find where is the problem. By the way I don't think that a coil is burned out, try to see some resistor possible burned out.
In case of a problem or clarification, don't hesitate to post.
Thanks and regards Please kindly rate this solution Stelios direct FixYa link: http://www.fixya.com/users/technical114
Make sure that Loudness switch is turned off & bass is not boasted up. Most cars have small cheap speakers that can't handle the bass. also its better to cut the low frequency from the woofer using a passive or active crossover. Most nowadays head units have got some sort of built in crossover. Refer to your head unit manual.