Axiom Home Page Forums General Discussion Technical Questions front channel speaker size and sub crossover

I have M22's, STF-1, and NAD T742. right now I have the M22's set to small. the NAD manual doesn't seem to tell me exactly what the crossover point is. it just says set speakers to small if they are not capable of reproducing the deepest bass from 20-100hz. is it possible the crossover point is really as high as 100hz? the STF-1 crossover is 90hz and below, so if that's the case I am losing a 10hz band. should I being using the M22's set to large with the STF-1 crossover at 60hz or so?

V, even as owners manuals go, the NAD manual is remarkably uninformative on this point. Your guess may well be correct; the reference to 20-100Hz may imply that the crossover in the 742 is at 100Hz, but they prefer to remain mysterious. Nevertheless, until you contact them about this, assume that it is 100Hz, set speakers small and bypass the internal crossover in the STF-1(by setting the switch to "out") so that it doesn't limit the upper range of the sub.

John

appriciate if you can pls explain what the following mean wrt subs
a. crossover in/out switch
b. phase 0/180 switch

thnx
Raj

Raj, as I told V, the crossover switch on your STF-1 should be set to "out", which bypasses the internal sub crossover so that the crossover on your 53TX can do its job at 80Hz without interference from the crossover in the sub.

The phase switch at 0 means that the subwoofer cone goes in or out in sync with the speaker cones. At 180, it would go in when the speaker cones go out. In some cases when the sub and speakers are widely separated the 180 setting may give stronger bass(experiment), but if there's little or no difference leave it at 0.

Thnx john. Yes, the sub sounds 'boomier' when its out of phase with the speakers.

Thnx once again
Raj

if I switch the sub to out, won't that provide muddy higher end bass? even with the crossover at 90hz it sounds worse to me than when at 60hz. I'm just afraid of pushing the M22's too hard without a crossover in place. guess I need to try and contact NAD somehow..

V, if by "a crossover in place" you're referring to the presently uncertain receiver crossover, yes, definitely use it by setting the speakers "small", so that some of the bass load is taken off the M22s.