Help with crossovers

[nhjrmonarchs7]

Hello,

I was wondering if you guy's could assist me with some good crossover frequencies to start with for my system. I am using 2 Martin Logan Prefaces for my 2 front speakers. I would also like to know a good starting point to try with my 3 Martin logan Encore speakers (center and 2 rears). Also, what size should I have them set as?

Currently I have the prefaces at 40HZ, and the encores at 70HZ. Sub LFE at 80HZ (THX).

Is this ideal? Any thoughts/comments on this are appreciated.


Thanks,

Ryan

 

[Boerd]

Let's take 50 Hz in your system. According to your setting you have 2 mains + the sub active (that is sub + 6db). At 75 Hz you have all the 5 speakers active + sub (that is sub + 15 db !!!!).
I'd rather use the sub up to 80 Hz and ALL the speakers above 80 Hz (crossed over at 80 Hz) - this way you won't have "fat" ranges.
Plus, setting the satellites or mains in the sub range will actually distort the sound; the mains/satellites have more distortion in the lower range - that's why you buy a sub.
My 2 cents.

 

[nhjrmonarchs7]

So even though my center and rear speakers can both go down to 70HZ and my 2 fronts can go as low as 35HZ, it is smart to set them all to 80HZ? I will test this tonight.

 

[JerryLove]

Can you set the crossovers separately for fronts and rears?

 

[nhjrmonarchs7]

I can set crossover separately for fronts, rears and center.

 

[highfigh]

Hello,

I was wondering if you guy's could assist me with some good crossover frequencies to start with for my system. I am using 2 Martin Logan Prefaces for my 2 front speakers. I would also like to know a good starting point to try with my 3 Martin logan Encore speakers (center and 2 rears). Also, what size should I have them set as?

Currently I have the prefaces at 40HZ, and the encores at 70HZ. Sub LFE at 80HZ (THX).

Is this ideal? Any thoughts/comments on this are appreciated.


Thanks,

Ryan

You need to remember/realize that a crossover doesn't chop the frequencies off at the low pass and butt the high pass up to it. If you set the low pass at 80Hz, you're sending about two octaves to the sub, with a 1 octave overlap in the front. This can do one of three things- the overlapping frequencies can add to each other (constructive interference), detract from each other (destructive interference) or selectively add and/or detract from each other (comb filtering), depending on where the sub is in relation to the front speakers and whether the speaker planes coincide and the sound emanates at the same time.

It's not usually good to have overlap in the crossover range but the room or situation may necessitate having a gap. What crossover frequency is "right" depends on what the room and speakers cause to happen when the sound is produced. The size of the room may make 80Hz a good choice for the mains, too, regardless of whether the spec sheet says they can do 35Hz.

 

[nhjrmonarchs7]

I will try to test this out tonight. I wish I had more experience with this!

 

[highfigh]

I will try to test this out tonight. I wish I had more experience with this!

Well, trial and error doesn't damage much if the volume isn't set too high, and if you lark the settings before you start, you can always go bacl to where they were.

You'd be surprised by how many cool things came about through inexperience, coincidence and unexpected results.