Phasecheck ( bonehead question, I confess )

swetarkus

with 2 tops & 2 subs, same brand througout, same 15" woofers in both subs and tops,
I'm getting the nagging feeling the phase might be wrong for the bass part..

With all wires being bought/branded, everything xlr & speakon, one would think that
couldn't be the case, but... I'm getting the sensation that the bass is stronger closer to the speaker
while in a more normal setup ( like home cinema, hifi, etc) which honestly is my normal turf, the "kick"
tends to come very central between the speakers...

So, for the sake of knowing; would the PA2 report any errors in the phase during the auto-measurements ?

Dra

All the "auto" can do is detect SPL. While phase, cancellations, etc affect SPL, it can't tell you that. You need Smaart or similar software.

By phase, do you mean polarity (as in wires reversed)?

DRA

swetarkus

Yeah,, as if the wires were reversed,, somewhere... with everything being "bought" and not homemade, one would that this isn't the case.
But, it's reminding me a bit like when one mixed up + & -1 on normal speakers on the homestereo and the bass was weakest center between speakers.

Seems that there's a smaart eval to download. Worth trying if it tells me something


Thanks,

swetarkus

well, must confess, to old and impatient for that smaart software...probably brilliant, But I don't feel brilliant after the 1st 5 mins..

Dra

It takes a weekend seminar to be comfortable with the basic. Years to be fluent.

Put the subs together. Leave one unplugged. Play a tone (60hz or so), or a looping low note. Plug in the 2nd sub. Did the volume increase or decrease? That will tell you if a speaker wire is reversed.

swetarkus

Thanks... actually did solve it !!
the 2 tops and the 2 subs have the same 15" woofers,
tried sub's only with "courtesy of the internet" in phase / out of phase signals,
the out phase sounded best !....which it of course shouldn't.

So, could make out the issue was with the subs.
took out the handles on both sides, and true,, +/- vs wiring was opposite between the subs.

So, then issue comes up, which sub is aligned with the tops ?
Took out their handles to check the woofers which of course used other wiring in another color !

In the end, running the in/out of phase check again, but instead per channel
together with Rage Against The Machine on high volume helped me with my fingers
feel the ones moving in unison.

Long story - but, switched the +/- on one sub and now everything sounds OK !

( still have the issue with the PA2 showing one channel less db's during gain check. Waiting for support on that one )
Thanks,

Dra

For a typical front loaded sub (speaker), the cone should move forward when pulsed with a + single.
Using a 9v battery, attaching the leads to the + to + and - to - will cause the cone to push out.
Attaching + to - and - to +, the cone will pull back. Some designs purposely reverse the polarity, but never change from box to box within a model (on purpose). Someone just made a mistake, or was feeling mischievous on the assembly line.
Not comforting that the wire color codes are not uniform. What are these speakers?

DRA

swetarkus

cheapish UK brand, Deltec.... so,, human factor obviously as I follow the leads and, no no uniform cabling between +/- between the 2 subs
and now with that sorted,, the 1/4 speaker acting out situation solved = everything tightened up considerably !!!