Phase testing tool?

[MCK]

Hi. I like to use a multi-amp layered together approach and take a lot of time to test & ensure I don't have any phase issues. I'm wondering if there is a tool that is designed to help with the process. If not I'd like to design something to this end. Appreciate any thoughts or insight you might care to share. Thanks much!

[Bob-I]

Use a dual trace scope and a sine wave to observe phase.

[MCK]

Thanks for the suggestion. I'm hoping to find or build something I can throw in a gig-bag and use on the spot. Something highly portable and idiot-proof.

[Cliff Schecht]

A permanently installed pocket scope?

[MCK]

Well, getting close to it are some really cool and low-cost iPhone scope apps. I checked one out and it looks pretty good. Perhaps I can look to use something like that but I was hoping to find a tool that allows me to pin point where the phase reversal issue is occurring as well.

[selloutrr]

they make test equipment for checking phase in audio systems. handheld testers. I'll be home in a couple days I'll post the model number. The kit costs about $3k.

you can also use a software program like smarrt live, for RTA, time align and phase. With a laptop, earthworks calibration microphone, and USB pre it's about as portable as it gets.

for speakers you can google speaker polarity tester or phase checker they make little handheld testers for under $200.

fluke also makes a portable oscilloscope that is about meter sized I'm +1 for the dual trace scope and tone generator it's the cheapest way to do it.

[MCK]

Thank you! 3k is definitely out of my league but will check all other suggestion. Appreciated.

[xtian]

Are you actually talking about phase? Because if we're talking about wiring one speaker cabinet backward, that's polarity (or 180 degrees out of phase but not time shifted), which would be easy to detect with your built-in sensitive equipment--your ears.

Are you really talking about two cabinets being slightly out of phase, where you might move one several inches back or front to solve an issue? I've never heard of that--everyone just lines up the speaker cabs in a wall of sound.

Let me know. I'm curious.

[Dr-Joned]

http://www.galaxyaudio.com/CRICKET.jsp

[paulster]

One thing I found really useful to help with identifying phase shifts as well as absolute phase was to create a test signal with the top half of the sine waves noticeably wider than the bottom, so I can use just a single channel to identify relative phase or use both channels to compare phase shifts between amps, for example.

[selloutrr]

I used delay lines with my bass rig to time align the 15" to the 10" speaker cabs. placed the SVT cabinets side by side in a line so they look cool and make the wall. then pink noise them and time align the signals so they are in line and not canceling out frequencies on the fret board. It's important to set your cross over correctly, over lapping frequencies will stand out.

I do the same thing for guitar cabinets, microphones, drum overheads. etc. The less phase shift I have to deal with the less Compression and aggressive EQ on the back side.

With that said. I also use phase shift to cancel out frequencies i don't like.

[MCK]

Thanks for all your responses. There is such a wealth of knowledge & experience here. In reply to one of the questions, yes, first off I'd like to be able to tackle any polarity issues quickly and some of the existing tools out there (Phase-IT, Cricket etc) should definitely help. The deeper phase issue I need to learn much more about and getting my head into it as we speak. Thanks once again for the guidance. Most appreciated.