Markbass CMD 121 Tweeter Issue

[Gib82]

Hey, I've done a few searches on this subject and didn't find anything.
I picked up a new CMD121p combo a few weeks ago. It's been great on the first few jazz gigs I've done on it "without a drummer". however, last night was my fist rock gig with the amp..... My EQ was flat ,gain was set at about 1 O'clock and the volume was a little over a quarter of the way up. the tweeter was distorting on pretty much ever note from my E and A strings. the only way I could get ride of the issue was to turn the VLE all the way up and pretty much have the tweeter off,
Is this due to the small cab size? Would adding the extra 12 cab resolve the issue? Does it sound like the tweeter is blown?


I would really appreciate some input!

Thanks

 

[tevitag]

Peter Murray is TB's resident Markbass specialist. Try PM-ing him. He is very helpful!

 

[KJung]

Hey, I've done a few searches on this subject and didn't find anything.
I picked up a new CMD121p combo a few weeks ago. It's been great on the first few jazz gigs I've done on it "without a drummer". however, last night was my fist rock gig with the amp..... My EQ was flat ,gain was set at about 1 O'clock and the volume was a little over a quarter of the way up. the tweeter was distorting on pretty much ever note from my E and A strings. the only way I could get ride of the issue was to turn the VLE all the way up and pretty much have the tweeter off,
Is this due to the small cab size? Would adding the extra 12 cab resolve the issue? Does it sound like the tweeter is blown?


I would really appreciate some input!

Thanks

Something not right here. First, I believe that cab has a piezo tweeter... so it either works or doesn't.

Tweeters are very sensitive to distorted signals, since most of the energy of a distorted/overdriven signal is in the upper frequency range. My guess is you were overdriving the input gain a bit, and hearing the preamp distort, primarily at high frequencies.

Make sure the preamp clip light does not come on EVER on the Markbass heads. To make sure, turn the master down (so you don't do any damage to cab or ears!) and pluck your open E as hard or harder than you ever would. Turn the gain up until you see that light flashing, and then turn it down about 'one hour level on the clock' if that makes sense.

My guess is, your issue will go away. Also, if you have an active bass with the treble boost cranked, that can result in some ugly stuff coming out of the tweeter.

 

[Bassman12350]

Something not right here. First, I believe that cab has a piezo tweeter... so it either works or doesn't.

Absolutely correct here, the CMD121P does have a piezo tweeter. As was mentioned, you may be overdriving the front end of the amp just enough to cause distortion of some of the highs - - which you'll hear through the tweeter. Also, piezos tend to quit working altogether when they blow, but rarely one can keep working and just be terribly distorted. Try readjusting things as KJung said, and if the problem still persists, the tweeter has probably gone south on you....