Michael F
Active Member
I wasn't sure if I should have posted this as an addendum to my original post,
http://www.audiokarma.org/forums/showthread.php?t=637865
start a new thread here or in the Speakers forum as it would apply to all speakers so I`ll let the moderators decide where this post will be of most value.
If you read my original post regarding the Infinity 7 Kappa acquisition, I was quite pleased with the speakers in general, so much so that I embarked on a spare driver quest when it was decided that they were keepers
The only thing keeping these speakers from attaining "perfect" status was the somewhat recessed placement of the soundstage relative to the plane of the speakers. While far from being a deal breaker, it was something that was easily adapted to as it had some positive attributes as well. A quick polarity test determined the midrange drivers to be inverted relative to the woofers and tweeters, probably owing to the crossover networks implementation so I just left it at that.
Fast-forward a few months and my driver searching mission brings me to not only spare drivers but a near mint condition, one owner complete pair,
what luck! Only the woofers were in need of new surrounds. Because this pair was in such nice shape, it only made sense that the original pair would become the donor unit and the woofers were transferred over and the speakers were placed in position, and put into service.
It didn't take long to realize that the new pair sounded noticeably different, but in a good way. It was difficult to pinpoint exactly what had changed but hey, it was a change for the better so I didn't question it further.
The soundstage did indeed get closer to me, there didn't seem to be as much activity beyond the sides of the speakers and the bass lined up with the rest of the spectrum better than before where it seemed to hit first, hmmm...
So then, after refoaming the woofers I decided to put them into active duty to give them a proper work out and let them break in properly.
This time the same quick polarity check (SCV thumper) revealed that all drivers are in correct absolute polarity, very interesting...
I double checked the wiring on the Polydomes as they were removed when the domes were cleaned inside and out and sure enough, everything checked out but which arrangement was correct?
The only schematic diagram I was able to hunt down came from a German Infinity website which had a 7 Kappa scan but it appears to have contradicting and or erroneous information.
It has the midrange unit listed as a part #902-3068 and not a 902-3075.
The revision date is listed as 6-98 which further reinforces my doubts as to the accuracy of the information. Despite all of that, it does however show that all drivers are wired in absolute phase so I think it would be a safe assumption that this is the correct configuration regardless of model version .
Knowing that, the changes that were noted made perfect sense in retrospect. Thankfully, the other positive attributes that made this system so appealing did not change, only complemented.
The whole point of this post is bring into question the integrity of your speaker systems polarity especially if it`s of the vintage or used variety. It`s clear to me now that some modifications or "upgrades" were done on my pair at some point by previous owners, something I`ve experienced before but those were largely relative polarity issues which are much more easily identifiable by ear. I would really have liked to have investigated the origin of my problem but unfortunately my original pair of enclosures and crossovers have been sold. I`m a little embarrassed that I didn't catch this earlier but I would have eventually following a pink noise measurement session.
Don't take things for granted, don't assume all is well, you may be pleasantly surprised!
http://www.audiokarma.org/forums/showthread.php?t=637865
start a new thread here or in the Speakers forum as it would apply to all speakers so I`ll let the moderators decide where this post will be of most value.
If you read my original post regarding the Infinity 7 Kappa acquisition, I was quite pleased with the speakers in general, so much so that I embarked on a spare driver quest when it was decided that they were keepers
The only thing keeping these speakers from attaining "perfect" status was the somewhat recessed placement of the soundstage relative to the plane of the speakers. While far from being a deal breaker, it was something that was easily adapted to as it had some positive attributes as well. A quick polarity test determined the midrange drivers to be inverted relative to the woofers and tweeters, probably owing to the crossover networks implementation so I just left it at that.
Fast-forward a few months and my driver searching mission brings me to not only spare drivers but a near mint condition, one owner complete pair,
what luck! Only the woofers were in need of new surrounds. Because this pair was in such nice shape, it only made sense that the original pair would become the donor unit and the woofers were transferred over and the speakers were placed in position, and put into service.
It didn't take long to realize that the new pair sounded noticeably different, but in a good way. It was difficult to pinpoint exactly what had changed but hey, it was a change for the better so I didn't question it further.
The soundstage did indeed get closer to me, there didn't seem to be as much activity beyond the sides of the speakers and the bass lined up with the rest of the spectrum better than before where it seemed to hit first, hmmm...
So then, after refoaming the woofers I decided to put them into active duty to give them a proper work out and let them break in properly.
This time the same quick polarity check (SCV thumper) revealed that all drivers are in correct absolute polarity, very interesting...
I double checked the wiring on the Polydomes as they were removed when the domes were cleaned inside and out and sure enough, everything checked out but which arrangement was correct?
The only schematic diagram I was able to hunt down came from a German Infinity website which had a 7 Kappa scan but it appears to have contradicting and or erroneous information.
It has the midrange unit listed as a part #902-3068 and not a 902-3075.
The revision date is listed as 6-98 which further reinforces my doubts as to the accuracy of the information. Despite all of that, it does however show that all drivers are wired in absolute phase so I think it would be a safe assumption that this is the correct configuration regardless of model version .
Knowing that, the changes that were noted made perfect sense in retrospect. Thankfully, the other positive attributes that made this system so appealing did not change, only complemented.
The whole point of this post is bring into question the integrity of your speaker systems polarity especially if it`s of the vintage or used variety. It`s clear to me now that some modifications or "upgrades" were done on my pair at some point by previous owners, something I`ve experienced before but those were largely relative polarity issues which are much more easily identifiable by ear. I would really have liked to have investigated the origin of my problem but unfortunately my original pair of enclosures and crossovers have been sold. I`m a little embarrassed that I didn't catch this earlier but I would have eventually following a pink noise measurement session.
Don't take things for granted, don't assume all is well, you may be pleasantly surprised!
