[warnerwh]

The reason I need to understand is because I am adding a subwoofer to my system that I am building. My present setup includes VMPS RM 40's and a New Original Sub.

The present sub is low passed with a 24b network and I have no option to change filter slopes on the plate amp.

The sub I'm building is a sealed design. What I need to know is if I can use the built in crossovers in my Cinenova amplifier. This amp has an adjustable high/low pass crossover built into each channel. These are second order filters.

Now if I run the sub I'm building with a low pass at 50hz and set the high pass for my RM 40's at 50hz with a second order slope will this cause problems like phase issues or something.

The reason I ask is because the RM 40's have 1st order high pass filters.

If need be I'll go buy an active crossover and run the RM 40s full range like I have been.

The reason I decided to build a sub is strictly for fun and education in the hobby. Whatever needs to be done including putting this sub upstairs with the HT system is fine. I really didn't need another sub as my present sub has way more than enough power as it's hardly turned on.

Any help would be greatly appreciated. Please explain why it won't work in simpleton terms   Thanks

[ctviggen]

Wikipedia has a pretty good intro:

http://en.wikipedia.org/wiki/Audio_crossover

You have to remember, too, that the physical distance between your sub and the RM40s will cause an additional phase delay.  Does your amp provide any type of phase modification?  If so, you would get rid of both the physical distance and crossover phase differences, at least to some degree.  Note, though, that the amplitude (see figure in the article above with gain) will be a bit different.  This might cause a slight dip (in amplitude/gain) around the crossover point (assuming perfectly aligned crossover points).

[warnerwh]

Thanks Bob. The reason I plan on making the crossover at 50hz is because I have a peak there. Then again with this second sub I may not. I'll have to measure my room and see what it looks like.

I've read phase issues can be inaudible and it seems like at low frequencies they would be the least audible. Presently my New Original is in a corner behind my right speaker. The woofer in the sub is behind the one in the RM 40 is 28" back. The plate amp I'm using has fully adjustable phase and the setting at zero is best.

With the setup for the second sub I won't have a phase adjustment but can move the sub forward and backward  from behind it to in front of  the left speaker.  Amplitude variations I should be able to take care of with the Behringer DEQ 2496.

If need be I'll buy a Behringer crossover. The better one has 6 parametric bands but is 250 as opposed to 90 dollars for the cheaper one. Both have adjustable phase and of course all the crossover slopes you could want. I was just hoping I wouldn't have to add another piece of gear. My four high double side rack is full already.