OHM Model 5 update and advice needed

MarvinS

Looking for advice from all with driver construction/property knowledge...most of you know more than I do.

Many of you heard my OHM Model 5's at last year's DIY Iowa event. I have since sent them for repair to OHM service department in NYC. Please bear with me on this lengthy story--I don't mean to trash OHM service in any way, especially since they continue to work with me to resolve the issues.

OHM required both driver cans to be sent so they could match a replacement tweeter to the other good tweeter. They replaced the dead tweeter, and found that the woofer surrounds had been replaced in the past by someone other than OHM. I agreed to their recommendation to replace the surrounds again since they judged them to be near end of life.

While unboxing the cans when they were returned to me, I could hear and feel something moving inside one can. I found the repaired tweeter was loose inside the can, but it did make music even though it was not pointing in the right direction. OHM shipped it back and found that "the stack of magnets" on the woofer on which the tweeter is mounted had separated. They repaired that and returned the can to me.

Until this point, I had no real expectation of how they were meant to sound since I either had a dead or loose tweeter. Now they should perform up to marketing hype, no? Uuuh...no. The tweeter repaired can sounded different from the other can. Pink noise in the repaired can sounds like ssheeee--quite thin sounding, and the other channel sounds like sshaaaa--a warmer tone.

Bass in the repaired can is also 6-8 db weaker compared to the other with 40 and 60 hz tones.

In general use, music blends the two timbres, but narration or TV news spoken voice draws attention to extra sibilance in the repaired can. I think the lack of bass there may account for the higher sibilance, but the tweeters may not have been matched properly.

Where I need your advice:
Could the lack of bass in one driver be caused by the suspension replacement?

If the woofers are mismatched, can that be compensated in the xover? Personally, I doubt it, plus, these xovers are nearly impossible to access in the bottom of the enclosure.

Do you ever customize xovers for each driver? Is that bad practice or impractical?

I hope to be better educated so I can be prepared to resolve this with OHM.

Thanks for your advice,
Marv

PS I posted at
https://techtalk.parts-express.com/forum/tech-talk-forum/1507229-how-to-design-for-mismatched-drivers

at first w/o revealing that I was asking about OHM speakers. Bill Fitzmaurice said the weak woofer must be defective.

ugly_woofer

It's difficult to say what the problem is without an impedance measurement at the very minimum. Perhaps someone lives close enough to take a measurement or can loan you a DATS. The way I see it Ohm is responsible for making it right reguardless if it is shipping damage or a faulty repair.

MarvinS

Thanks for your response, Nick. They sent shipping labels yesterday and I intend to review expectations on the phone before I ship them. I hope they can get them to match properly.