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<blockquote data-quote="Per SÃ¸vik" data-source="post: 117000" data-attributes="member: 1285">Re: Phase align subs to mainsI guess I might ask if you need an analyzer to set the crossover frequency? :razz:Basically, when setting the low-pass frequency and slope for the subs, one takes into account the response and intended gain/level of the subs to hit the intended crossover point where both systems are equally loud. 3dB extra on the subs with a 24dB/oct slope shifts the crossover point by 1/8 octave and so on.However, for pure time alignment, to get back to the OPs problem, it is fairly easy to get a time reference if one isn&#039;t using bandpass subs. Frontloaded BR subs have response high enough in frequency to get accurate timing if one runs the trace on the subs without the low pass filter engaged (or actually set really high so the timing is representative). Of course, resetting the filter will alter the phase, so that has to be accounted for, but you can get a baseline time by this method. Using the baseline time as a starting point for the delay setting, and then tweaking the alignment delays and filters while looking at the full system response and phase. ( one should not be too concerned with finding the actual propagation delay for the different parts of the system since it all has to work to the same time reference eventually )Knowing the system, i.e. what is the base alignment times when the system is on a single axis in open air is of course a big help in setting up any system.</blockquote>

[QUOTE="Per SÃ¸vik, post: 117000, member: 1285"] Re: Phase align subs to mains I guess I might ask if you need an analyzer to set the crossover frequency? :razz: Basically, when setting the low-pass frequency and slope for the subs, one takes into account the response and intended gain/level of the subs to hit the intended crossover point where both systems are equally loud. 3dB extra on the subs with a 24dB/oct slope shifts the crossover point by 1/8 octave and so on. However, for pure time alignment, to get back to the OPs problem, it is fairly easy to get a time reference if one isn't using bandpass subs. Frontloaded BR subs have response high enough in frequency to get accurate timing if one runs the trace on the subs without the low pass filter engaged (or actually set really high so the timing is representative). Of course, resetting the filter will alter the phase, so that has to be accounted for, but you can get a baseline time by this method. Using the baseline time as a starting point for the delay setting, and then tweaking the alignment delays and filters while looking at the full system response and phase. ( one should not be too concerned with finding the actual propagation delay for the different parts of the system since it all has to work to the same time reference eventually ) Knowing the system, i.e. what is the base alignment times when the system is on a single axis in open air is of course a big help in setting up any system. [/QUOTE]

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