Mixing R&L designated and non designated dipoles in a 7.1 setup?

[demoncamber]

7.1 bedroom setup, dipoles as rear & side surrounds.
That's right, I just recently setup a quick and dirty 7.1 setup in my small bedroom.

I'm using the Phase Tech DS-T dipoles as my side surrounds and my TSC TSS dipoles as the rear surrounds.

Now, the newer TSS's have a designated R/L placement but the DS-T's do not.

I got in contact with one of the Phase Tech engineers asking about this situation and his reply was: "At the time we were making the DST surround speakers there was only Dolby Pro Logic and the design standards for surround sound were still being developed. These standards did not really happen until Dolby developed THX standards and Dolby Digital and the industry agreed as a whole on speaker configurations.

The DST while it is a di-pole speaker was not made as specific left and right models so there is no designation or specific placement for the speakers to conform to applications today. The successor models of the DST all have been made as left/right pairs and do have indicators on the speakers for proper placement.

Since the DST is only a 2 way speaker, what makes it a di-pole speaker is that one of the tweeters is connected out of phase with relationship to the other tweeter in the speaker cabinet. There are 2 tweeters per system. Since this only effects the frequencies above about 3-3.5 kHz and the tweeters are aimed off axis, you would be hard pressed to tell a difference in the surround imaging based on which tweeter was facing the main speakers unless the DSTs were place very close to your head in the listening environment. You do not want to reverse the phase of the speakers at the input connection, this will make the issue much worse.
I would suggest that you just hook them up and enjoy them."

Now, with knowing that, how should I go about setting up my system in terms of using two sets of dipoles for the rear/side surrounds?

I was told that you would basically take the rear dipoles and swap the left to right and keep the side dipoles at their correct R/L designations, however that would only be correct with two pair R&L designated dipoles.

See:

So the engineer did state that one of the tweeters are connected out of phase on the DST's but, isn't that the whole point of the R/L designation???

So that bit confused me; However how would you guys suggest connecting the phase for my dipoles to work correctly with each other?

As far as I can tell, I opened my DS-t's and both tweeters seem to be connected the same way, wires are color coded, so it appears that all drivers are in phase, which coincidentally is how I would want that setup correct? So that the front and rear tweeter array's were both in phase with the front speakers and to the rear dipoles.

However, though the tweeters are color coded and hooked up correctly, the phase swap could have happened at the crossover, which is going to a board and I have no idea how to read that.

 

[demoncamber]

Shouldn't I be able to figure out phase with a multimeter?

Positive probe on the input + terminal then negative probe onto the positive wire going from the crossover to the tweeter, then try all the other wires, that should give me an answer correct?

 

[highfigh]

Shouldn't I be able to figure out phase with a multimeter?

Positive probe on the input + terminal then negative probe onto the positive wire going from the crossover to the tweeter, then try all the other wires, that should give me an answer correct?

That won't show anything. Use a AA battery and watch which way the cone moves. The tweeter won't see the DC but the mid will. When it moves out, your battery + is on the speaker +.

 

[demoncamber]

I have verified the mid's phase as being correct with the battery test, however it's the tweeters now that need to be verified, and apparently I cannot do so without knowing the way this specific crossover is wired...

I've tried listening to each tweeter next to my front speakers, putting my head between my front's tweeter and the DST tweeter flipping it around to listen to each side, and one side appears to be brighter and more defined than the other... but it's so subtle, and still not sure if I'm just hearing things or which is which.

 

[Tubamark]

Shouldn't I be able to figure out phase with a multimeter?

Positive probe on the input + terminal then negative probe onto the positive wire going from the crossover to the tweeter, then try all the other wires, that should give me an answer correct?

None of that is necessary. It's easy under nearfield listening conditions to learn how to distinguish phase by ear.

Hold the speaker in front of you (get away from walls) so that you are hearing both sides at the same time. Feed the speaker pink noise or white noise. The signal should be strange - Hard to localize. This is the hallmark of a dipole (out of phase drivers). If the sides are IN phase, the sound is very "centered" and the speaker is a BIpole, not a dipole.

If unsure what to listen for, here's how:
Sit in the nearfield of a small pair speakers, and play a monaural signal. Invert the polarity the input cables to one speaker. Invert again. Repeat. When in phase there will be a very strong "phantom" center image. When out of phase there won't be a coherent 'image'. With this exercise, it should become easy to learn how to distinguish between In-phase and Inverted-phase signals.

The effect is much harder to distinguish if one has average to lousy room acoustics - that is why it is important to do this with listener and speakers much closer to each other than to any room surfaces.

-- Mark

 

[demoncamber]

Thanks for that last post, I actually lucked out and got a response from one of the engineers who made the DST's and corrected himself by stating they are in phase and actually dipoles. Problem solved!