no sound in tweets db6501

sonnydaniels

hello all, this is my first thread, and polk products. so I recently bought 2 sets of 6.5 db6501 for my 96 blazer as well as a set of polk 4 x 6 plates for the dash. I had my system installed by a shop they laid down new wires in my truck when installing them (FYI) heres the thing I have no sound coming from my tweets, everything else works fine. I have those 6 speakers and tweets, and a 12inch kicker comp all of my truck is run by a 2 channel mtx 400watt amp with a 2farrad audiobahn capacitor, when I brought my stuff to the shop they said they would run everything through the one amp, Im going to add a 4channel 800watt audiobahn to power the 3 sets of polk. anyway when they initially setup the speakers they only used 2 crossover boxes rather than all four after taking my car out I realized that no sound was going to the tweets the mids and lows work fine, I brought it back in to have them fix it and they reconnected it the way the manual said to and they couldn't get the tweets to play, we connected the tweets to another stereo to see if they are blown they worked fine. they guy working on my system said he thought the cross over boxes were not functioning, he tested 3 of the 4 and they were not working(the tweet plugs). I want to know what you all think the issue is. please help, I dont know where to go. thanks guys