First Listening After Lift Off

Well, its been a week and a mighty struggle to get to first base with this new OB experimental sporting the SEAS 8″ and the AMT-700 tweeter. At first all sounded wonderful with the euphoria of having built a new speaker. But it didn’t take long to notice something as not quite right. Overall the balance was mostly correct but there was this annoying lift in lower midrange, a sort of hack as compared to honk. Or to be more precise, around middle C. This was diagnosed using parametric equalizer sweeps of the DEQX to help isolate the offending frequency. The other issue was I had lost my beautiful imaging of the final Haffner which would just hold a singer in centre stage with no hint of two separate speakers reproducing a mono signal. This is something very hard to recreate and is entirely down to time accuracy across the midrange spectrum. How any of the speaker manufactures do this without DSP is beyond me.

So whilst I was generally happy with the overall result, I found it more and more difficult to live with this hack in the midrange. It is this type of broad lift that is the primary killer of lesser speakers. Hell, I could even hear three rooms away it was so annoying, at least once one knows what to listen for.

apart from that, this was my first real experience of an OB speaker. Quite different having the sound stage sort of splashed across the back wall. It should be noted that the baffle is only 2 feet out from the back wall and this is considered a little tight with many people preferring 3 feet. This give more delay to the reflected sound and thus enhances the depth of the sound stage. This is the great party trick of open baffle and planner speakers. In fact it was  in part due to the Magnepan speaker at Mcleans Hi Fi in East Gosford that helped kick off this whole quest.

A week later and I still I am struggling to eliminate that hack in the midrange and will have to go to the next level of a DEQX calibration to see if that fixes it. Otherwise I won’t be quite happy with the results so far.