Audio Systems: Denon speaker problem, japanese speakers, speaker unit

Question
Hi,

I have a set of 60w Denon floor stand speakers, 2 way, SC-T11R.

One of them has lost bass and all depth, and sounds like crap compared to the other.

I changed the cables / channels around to check the amp, and it is definitely the speaker.

The cones look fine. I live in an apartment, so they have never been exerted to full capacity.

What could the problem be? Is it easily fixed? Should I buy Japanese speakers instead of China made ones next time???

Thanks very much,
A  

Answer
Probably the bass driver unit has gone open. This could be from a broken wire inside the box or an open voice coil inside the speaker unit itself.

Do this: At the back of the amp, just reverse the wires going to the speakers; left to right and right to left. If the bad sound switches channels then you know it is the speaker or wiring to that speaker. If the bad sound stays on the same channel then the amplifier has gone bad.

I assume you will find the speaker is bad.  Here is a way to check it.  Using a D cell or 9v battery and a  length of wires disconnect the wiring from the amplifier then connect the length of wires to the battery terminals. Then touch the other end of the wires to the speaker terminals. If the bass driver is working you will hear a thud or blump noise when the battery terminals are connected and disconnected.  If you remove the grills you should be able to see the cone move in or out when the battery is connected.

If you do not get the expected result you can assume the speaker is deficient.  You have several options.  Replace it.  Send it or take it out to a repair shop.  Open it up and attempt to repair it yourself.

To check it yourself you will have to open up the box and get inside to examine the physical condition of the wires from the terminals to the speaker unit.  Sometimes the connection to the bass unit will fall or break off.  Or, sometimes it will be the flex wire going from the terminal on the speaker unit to the voice coil on the cone.  If you have a soldering iron you can repair it yourself.

Let me know if you need further guidance.
C