dead DT SM55 speaker. Any idea of problem?

[NoobieHolic]

I have a pair of the DT Studio Monitor 55 bookshelf speakers. About a week ago 1 speaker lost sound. The odd thing is that the tweeter is still putting out sound. If this was caused by me turning them up too loud and I blew this speaker out, then what would I see?

There is no visible damage to the cone. I had thought I figured out the problem when I opened up the speaker and noticed that a thin bare copper wire (the negative) had broken away from it's solder contact area located at the neck of the magnet. I did a good job soldering this wire back in place, but I'm still not getting sound from it.

I checked every connection and everything is connected properly inside the speaker. Of course prior to that I checked all my speaker wire, and all my component connections. The other speaker works fine if connected to the dead speakers left front location so I can rule out any signal problem from my Emotiva XPA-3 Amp.

I fear the problem may be with the small board inside the speaker with all the capacitors and such on it. I do like the sound of these speakers and would say at only $600 for the pair they are about the best I could have bought. On the other hand upon opening the speaker I was a little disappointed to see what to me appears to be some cheap press wood and even cardboard used in construction.

I suppose I was expecting a higher level of materials and construction. Could I have caused this failure by playing them too loud?
If anyone might have an idea of what may be wrong with this speaker please let me know.

 

[TLS Guy]

I have a pair of the DT Studio Monitor 55 bookshelf speakers. About a week ago 1 speaker lost sound. The odd thing is that the tweeter is still putting out sound. If this was caused by me turning them up too loud and I blew this speaker out, then what would I see?

There is no visible damage to the cone. I had thought I figured out the problem when I opened up the speaker and noticed that a thin bare copper wire (the negative) had broken away from it's solder contact area located at the neck of the magnet. I did a good job soldering this wire back in place, but I'm still not getting sound from it.

I checked every connection and everything is connected properly inside the speaker. Of course prior to that I checked all my speaker wire, and all my component connections. The other speaker works fine if connected to the dead speakers left front location so I can rule out any signal problem from my Emotiva XPA-3 Amp.

I fear the problem may be with the small board inside the speaker with all the capacitors and such on it. I do like the sound of these speakers and would say at only $600 for the pair they are about the best I could have bought. On the other hand upon opening the speaker I was a little disappointed to see what to me appears to be some cheap press wood and even cardboard used in construction.

I suppose I was expecting a higher level of materials and construction. Could I have caused this failure by playing them too loud?
If anyone might have an idea of what may be wrong with this speaker please let me know.

Test the driver with a 1.5 volt battery. Put it across the terminals of the speaker and see if the cone throws. I suspect you did not do a good job soldering and have a dry joint.

The wire has enamel insulation, which needs carefully stripping away with a very sharp knife without doing further damage. Both ends to be soldered need to be bright shiny copper before applying solder. It is worth a try to redo this. However I suspect you have over driven the driver, as a wire detachment at the voice coil is usually indicative of more widespread thermal damage to the voice coil. I suspect this driver needs reconing.

 

[NoobieHolic]

Test the driver with a 1.5 volt battery. Put it across the terminals of the speaker and see if the cone throws. I suspect you did not do a good job soldering and have a dry joint.

The wire has enamel insulation, which needs carefully stripping away with a very sharp knife without doing further damage. Both ends to be soldered need to be bright shiny copper before applying solder. It is worth a try to redo this. However I suspect you have over driven the driver, as a wire detachment at the voice coil is usually indicative of more widespread thermal damage to the voice coil. I suspect this driver needs reconing.

Thanks... Yes there was some enamel insulation at this soldered ground point. I did fail to carefully strip that off before my solder of this copper negative wire. I may have failed to make a good ground contact because of this. These speakers were bought new just 90 days ago. I called DT tech support and much to my shock the support Rep made things very simple. He just took down my address and Name then said, "I'm sending you a new replacement cone." I was pleased that he trusted I had already confirmed it was a speaker issue and didn't have me run thru tests I had already done.

It's only been a couple days since my call and hope to get the new cone this week. (All be it I am a little suspicious that this guy would simply ask for nothing and just mail me a new cone.) In my experience getting a warranty replacement from any company has always been a huge pain in the neck.) I guess I shall see if and when the new component arrives. He said if that fails to correct the issue then to just mail the entire speaker back and they would send me a new one. Good speakers, but I might sell them and foot more money to buy a higher end pair of Bookshelf speakers in the $1,200 a pair price range.

My sound source really stinks (Just an LG Wifi Bluray with internet player.) it Plays my CD's ok and Pandora sounds ok, but I want a great internet and disk player. Something that can provide me a better sound source. Looking at one from Oddo but not sure if it has fully built in Wifi capability or if I must buy a separate Wifi Dongle for it. If anyone has any tips on a great all in one internet player that can play CD, DVD, Bluray, MP3, and provide my Pandora also then please toss me a few suggestions. Looking between the $400 to $600 range.

 

[TLS Guy]

Thanks... Yes there was some enamel insulation at this soldered ground point. I did fail to carefully strip that off before my solder of this copper negative wire. I may have failed to make a good ground contact because of this. These speakers were bought new just 90 days ago. I called DT tech support and much to my shock the support Rep made things very simple. He just took down my address and Name then said, "I'm sending you a new replacement cone." I was pleased that he trusted I had already confirmed it was a speaker issue and didn't have me run thru tests I had already done.

It's only been a couple days since my call and hope to get the new cone this week. (All be it I am a little suspicious that this guy would simply ask for nothing and just mail me a new cone.) In my experience getting a warranty replacement from any company has always been a huge pain in the neck.) I guess I shall see if and when the new component arrives. He said if that fails to correct the issue then to just mail the entire speaker back and they would send me a new one. Good speakers, but I might sell them and foot more money to buy a higher end pair of Bookshelf speakers in the $1,200 a pair price range.

My sound source really stinks (Just an LG Wifi Bluray with internet player.) it Plays my CD's ok and Pandora sounds ok, but I want a great internet and disk player. Something that can provide me a better sound source. Looking at one from Oddo but not sure if it has fully built in Wifi capability or if I must buy a separate Wifi Dongle for it. If anyone has any tips on a great all in one internet player that can play CD, DVD, Bluray, MP3, and provide my Pandora also then please toss me a few suggestions. Looking between the $400 to $600 range.

Did the guy tell you how to recone a loudspeaker and send you the correct glues, shims and a dust cap?

The voice coil must be centered in the gap. Otherwise you will have gap rub and the speaker will buzz to high heaven.

Speaker reconing is a special skill set. I can talk you through it, but this speaker is in warranty and they should have sent a complete driver at the minimum.