Axiom Home Page Forums General Discussion Technical Questions M80ti Crossover Problem (I think)

Intricate,

To make the comparison fair, you should place your two speakers side by side. It could be that one of the speakers is in a location where boundary reinforcement emphasizes the bass output more.

Moreover, a tube preamp's frequency response is rarely linear or smooth, especially compared to solid-state, so unless you measured the frequency response of the tube preamp, it could well be the contribution of the tube preamp that's emphasizing bass. Typically, the generous amounts of harmonic distortion from tube gear sometimes adds a "warmth" to bass reproduction.

By the way, you can ignore that Ninja site. The info there is simply wrong. And as kcarlile pointed out, cable length will have no influence at all.

Regards,
Alan

Hi Alan,

I was awaiting your response. At this point I have eliminated the tube-pre entirely and am using a single channel on my mixer and panning between the left and right channel. I have isolated the problem to be with the speakers as I've swapped the cables to and from the amp one between the other.

Furthermore, playing with the EQ on the mixer I'm 99% sure that the tweeter and mid drivers are responding identically. It is just the low frequency drivers that are contributing to this problem - although they are working.

To start with the troubleshooting, how hard would it be to swap the crossovers from one speaker to the other? Are the drivers plugged in or soldered onto the board?

So I removed the screws on the back of the input and visually examined the crossover. (The cables to the drivers are soldered btw)

There doesn't seem to be any damage, I'd like to swap the units between speakers to see what happens but I'll wait for Alan's response first.

Some additional information.

Doing a 100hz cut in the material makes the problem indistinguishable.

Hi Intricate,

I don't see a problem in switching one crossover to the other speaker if you're confident of your soldering skills. It's rare, but sometimes there can be a defect in a crossover board or a cold solder joint.

Are you using a mono test signal to each speaker? Is each speaker receiving the same signal (i.e. not a stereo signal) because there is no assurance using a stereo signal that bass is mixed equally into both channels.

I would say you need to confirm all the drivers are working before you get too involved with the possibility of the crossover as a bad woofer will certainly make a huge difference both in spl and it may have a muddying effect by reverberating with the good drivers(just a possibility).

I think it would be easier to swap all the drivers over than to desolder the crossovers and swap them around. The drivers have push on terminals.

Rob, as Adrian and Jason pointed out, it would appear to be simpler for a "start with the trouble shooting" to switch the bass drivers rather than the crossovers. The simple fact that they're working to some extent doesn't answer the question.

That will definately make life a lot easier (considering the drivers have push on terminals). I wasn't really up to resoldering the crossover at this point.

I'll try swapping the drivers over next weekend or if I get some free time during the week and report back. I appreciate all of the comments, ideas and feedback.