EAW Tops
Dr. J
Posts: 209
Hey guys -- I have a question that re-visits the polarity issue. My buddy just got some EAW KF-461 TAVS Tops and we checked the polarity. They are biamped and loaded with a 15-in woofer (vented), a horn-loaded 8-in MF cone and a 1.4-in exit/44mm voice coil HF compression driver on a 60 x 40 constant directivity horn. The 15's checked out Ok, The high frequency drivers checked out Ok BUT the 8 inch's speakers did not. The both show \"INVERTED\". This was checked with a Galaxy Cricket. Is it common for an 8 inch speaker to be inverted on these intentionally? Or could it be that it is wired backwards? Here we go again.......
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Now I don't have the time right now to determine which drivers are which... but the processor page for EAW clearly states the MF/HF are NEGATIVE:
http://www.eaw.com/info/EAW/Processor_S ... S_rev2.pdf
While the LF is positive...
Looks like the LF sits alone though... and the MF/HF are together in revers-phase ville....This could be because the horn length takes enough phase shift to warrant phase
Thats my $.02
G
When time aligning a speaker cabinet, drivers can start out many degrees out of phase from each other. It is possible that inverting the polarity on one driver will bring the phase response at the xo point between it and the other driver much closer to being the same. In that situation, after the polarity is inverted, it will require less delay to complete the alignment.
Gadget, your post indicates that a previous owner possibly \"modified\" the 461s. I think I can get my hands on some LA460s to test and see if both the horn and mid are inverted.
Dennis
Those were my \"EAW\" 'acoustic partner' parameters...provided by them...so who knows. Perhaps the MF/HF crossover has inherent phase shift.. as you have speculated...
:?:
Dennis
G
The PEQ's and Shelf filters are included...note an adjacent BW24 filter with a significant 125 hz spread from the 392 hz LPF for the woofer to the 517hz HPF of the mf/hf section...However a PEQ @ 517 hz is in place to account for that spread...
Yes they are using a passive crossover for the mf/hf crossover I assume the HF inverse to the mf driver is taken care of in the filter.
As for the processor settings... yes they can be entered into any processor.. that has the capability of matching the specs...the Driverack would need some small differences since the processor settings aren't exactly duplicatable... but you can get close... The MFG's have much more resources to provide tuning info for their speakers... unless you are very adapt at tuning speakers you would do well to utilize the OEM setup.. I know I rail against that but that is for ME, and Mikey, and Dennis who have years of experience and tools at our disposal to make this a personal thing... that we get the speakers tuned the way WE want them...
I know for a fact that old KF300e or KF300i ganged the mids and highs together and the woofer was by itself. The current model KF300z gangs the woofer and mid together leaving the horn by itself. When you read the specs, you have to be aware of vintage. I can't keep up with all of this crap.
So Dr. J, lets say two drivers time align at 128* of phase due to the individual characteristics of each driver. Your options with polarity are 0* (non-inverted) and +180* or -180*(inverted). 180* is closer to 128* than 0* is. So you invert, then add delay to the correct component to bring 180* down to 128* (which is less delay than bringing 0* up to 128*). Some situations give you no choice and you have to invert...other situations are a judgement call.
Dennis
Hey..it's just a theory.
Dennis
Dennis
As for the EAW's some passive crossovers shift the phase a whole bunch I suspect that the mid and HF are matched @ reverse polarity.. so do that and treat the speaker like a 2 way...use the parameters that EAW provides unless we find a better solution that is proven... I suspect they are out there...
G