Another 10B question:

Crimson · « **on:** 19 May 2005, 10:29 am »

When selecting the slope on the 10B, is there the associated phase shift (90 for 6db, 180 for 12db, etc) that is inherent in first, second, and third order crossovers? Or are the outputs electronically phase-compensated relative to each other?

Thanks.

James Tanner · « **Reply #1 on:** 19 May 2005, 11:45 am »

Hi Crimson,

Yes the phase shifts as you stated - they are Butterworth filters.

james

Crimson · « **Reply #2 on:** 20 May 2005, 12:19 am »

Thanks, James.

Crimson · « **Reply #3 on:** 25 May 2005, 09:40 pm »

Ooooh, I forgot. One more question:

With my current setup, I have asymetrical crossovers set at 6db and 18db per octave, per side. This would mean the high pass and low pass feeds to each speaker are 180 degrees out of phase. Theoretically speaking, would swapping the polarity of, say, both speakers' low-pass connections correct this relative phase difference?

Thanks.

James Tanner · « **Reply #4 on:** 26 May 2005, 04:25 pm »

The problem is that where you are - where the sub is - and where the mains are - will be different in every room. The phase relationships between these 3 placements means that the resultant phase at the listening location will be slightly different for each installation.

What you want to do is play around with the lowpass and highpass slope switches on the 10B until - at the listening location - the bass ( at the crossover point) is tight and well defined with good transient response.

james

Crimson · « **Reply #5 on:** 27 May 2005, 12:25 am »

Thanks again, James. No sub in this setup. I'm powering the bass panel of a planar speaker via the low pass, and the mids and highs via the high pass. I was curious if swapping the polarity of the bass panels would negate the relative phase difference between them and the mids/highs, all else being equal.

James Tanner · « **Reply #6 on:** 27 May 2005, 01:31 am »

OK - different question.
It depends on the slopes and the phase used by the manufacturer of the speakers.
Are the speakers Maggies?

james

Crimson · « **Reply #7 on:** 27 May 2005, 10:24 am »

Yes, 3.6's to be exact. The manual states an external active crossover with low pass for the bass panels set to 18db/octave @ 250 Hz, high pass set to 6db/octave @ 200 Hz for mids/ribbons. Per your earlier responses, this would indicate a relative phase shift of 180 degrees between bass and mid/high panels. Thus my question of swapping polarity at one set of speaker terminals per speaker.

James Tanner · « **Reply #8 on:** 27 May 2005, 01:49 pm »

I know the speakers well - the Maggies use Butterworth filters ( same as the 10B) - so leave it connected with positive to positive and negative to negative.

james

Crimson · « **Reply #9 on:** 28 May 2005, 01:36 am »

Thanks, James.