Working on some of my own speaker designs has made me appreciate the Abbey's more. I finally took them outside on my back patio
to do some correction with my DEQX so I thought I'd post the anechoic responses I took outside for the group. I find at least with the deqx
they (and most) speakers sound better when I dont touch the eq (even if its wavy gravy) and just correct the group delay and step response and phase.
This gives me the most realistic soundstage. I think its something about the various filters that doesnt do as well correcting magnitude for some reason.
I upgraded these from the DE250 to the DE500 Neo compression drivers. The woofers are the non neo BC B&C 12TBX100 I would like
to hear from anyone who has also upgraded the woofers to the neo version if it made a significant difference. Whoever built these (I had them
imported all the way from Poland!) Used premium caps and resistors. I wont post pictures of the crossover to protect Earl's IP.
They also do really well tilted up against the wall on the floor under a projection screen like I have. the 132hz f3 gets filled in nicely down to around
80hz by room gain to mate with a sub.
to do some correction with my DEQX so I thought I'd post the anechoic responses I took outside for the group. I find at least with the deqx
they (and most) speakers sound better when I dont touch the eq (even if its wavy gravy) and just correct the group delay and step response and phase.
This gives me the most realistic soundstage. I think its something about the various filters that doesnt do as well correcting magnitude for some reason.
I upgraded these from the DE250 to the DE500 Neo compression drivers. The woofers are the non neo BC B&C 12TBX100 I would like
to hear from anyone who has also upgraded the woofers to the neo version if it made a significant difference. Whoever built these (I had them
imported all the way from Poland!) Used premium caps and resistors. I wont post pictures of the crossover to protect Earl's IP.
They also do really well tilted up against the wall on the floor under a projection screen like I have. the 132hz f3 gets filled in nicely down to around
80hz by room gain to mate with a sub.
Attachments
Don't forget that final performance also depends on the characteristics of the amplifier driving it; mainly its output impedance and damping factor.
An anechoic response would be free of echo and reflection, the response posted in the OP looks like it may have floor (patio..) reflections causing "wavy gravy" response that should not be in the speaker's raw response.
Correcting for floor bounce would be problematic, as response changes with distance and angle.
What were the mic and speaker placement and distance relative to the ground plane in your measurement?
Yeah, there was nothing I could do about that boundary, Speaker is 4' off the ground. So not perfectly anechoic for sure, but much freer from reflections than inside of course
Now you've got my mousewheel turning. Think I'd get a better correction measurement from a ground plane measurement instead of 4' off the ground? My mic was about 18" away IIRC
18" is too close for a ground plane or free field measurement for a speaker of this size.
Within the near field, the frequency response changes too much with mic position to be useful for correction.
A working “rule-of-thumb” for determining the boundary between near-field and far-field is to make the minimum measurement distance the longest dimension of the loudspeaker multiplied by 3.
Pat Brown's explanation here:
https://www.prosoundtraining.com/2010/06/28/far-field-criteria-for-loudspeaker-balloon-data/
Within the near field, the frequency response changes too much with mic position to be useful for correction.
A working “rule-of-thumb” for determining the boundary between near-field and far-field is to make the minimum measurement distance the longest dimension of the loudspeaker multiplied by 3.
Pat Brown's explanation here:
https://www.prosoundtraining.com/2010/06/28/far-field-criteria-for-loudspeaker-balloon-data/
I have an Abbey 12 speaker that I purchased from Earl Geddes in ~2010 that has a failing B&C DE250 compression driver. I believe that the model was changed and Earl went with a different driver possibly the DE500 you're discussing here. Does anyone know what driver he went with and how to change the crossover?
Thanks,
Tom
Thanks,
Tom