I recently bought the Epic 80 system minus the sub, and I am wondering if anyone here could post the frequency response curves for the M80tis, the VP-150 center, and the QS-8 surrounds. I am looking for the best starting place to cross over to the sub. Any help would be greatly appreciated!
I dont know if they have it or not but try looking in the reviews for the M80's and epic 80 system.
Im sure Ian or alan will be able to tell you where is a good place to start.
Stunning how quickly you both replied! Thanks for the info...now can anybody help on the center and surrounds? (especially the center!)
I havn't been able to find anything on those other two, but I'd imagine that the VP150 is fairly close but without the extended bass response.
I'd personally set the reciever's crossover at 50 Hz (since that is most likey a second order Low Pass crossover to the sub and first order High Pass for the mains), and then have the sub's Low Pass crossing over at about 60-70 Hz (as that can be either first or second order - and experimentation and room placement have a big factor here).
Bill, although the M80s have substantial bass of their own, as shown by the anechoic response curve Will(DJ)linked, I'd suggest that you still use the THX recommended 80Hz crossover for all speakers. If your sub is good(and the 16-46 certainly is) it will be still better than the M80 in that 40-80Hz octave and should be allowed to do what it does best, relieving the M80s of part of the load there. Also, that crossover is suitable for the VP-150 and QS-8s, so don't be concerned about any tweaking of that area(even if your equipment can set different crossovers).
Unless you can set different crossover points for the center and surrounds....I would set the crossover no lower than 80mhz. The +/- 3db point on the VP150 is 85hz, and on the QS8 it is 95hz, setting the xover at 80mhz would seem to leave a gap.....that would concern me more for the center than the surrounds. The center carries a lot of special effects info.
-curtis
I have an Outlaw 950 pre/pro. It has the ability to set different crossovers for the mains, center and surround. My options are 40hz, 60hz, 80hz, 100hz, and 120hz. I was thinking 60hz, 100hz, and 120hz respectively for the M80s, the VP-150, and the QS-8s. This was based of the -3db points of the speakers and the fact that the center and surrounds are sealed while the ported M80s will have a greater rolloff and need to be crossed over about an octave higher than their -3db point. Am I incorrect?
So, I'd try the subwoofer crossover point at 70 Hz.
Bill,
I would not set the crossover for the center and the surrounds much higher than 80Hz. The main reason is that the higher the frequency components your sub has to play, the more the sub sound become "localizable" -- the illusion of the deep bass sounds coming from 5 main channels instead of the sub will be more likely to be destroyed. Regardless of the published frequency specs for the VP150 and QS8, these speakers are designed so that they comfortably perform in a 5.1 setting with 80Hz crossover to the sub.
The optimal crossover frequency for the M80s depends heavily on the room acoustics and your own sonic preferences. Only the actual experiments with different crossover frequencies will tell what's best for you in the particular room. I would experiment with 40, 60 and 80Hz, without making any preconceived "theoretical" assumptions that one of these should be best. Rest assured that even if you end up with 80Hz crossover, you will not be "wasting" anything out of the M80s. Relieving them of the power- and driver-excursion-hungry bass duties may well result in an improved sound quality in the mid-bass region and above.
