Axiom Home Page Forums General Discussion Stereo Crossover setting for a Sub

Thanks John for the advice. I still have to experiment with the strange REL suggestion. Who knwos, it will probably work...

As for the receiver, I don't have one, my system is a two channel system with a preamp that does not have bass management whatsoever.

I got another email from REL distributor in USA, now he starts to make more sense:

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The REL is connected at High-level, which means you use the crossover in the REL, not the bass management features in the preamp. The REL is connected to your power amp. The REL connector attaches to the same binding posts to which your speaker cables connect (they share the binding post). The REL crossover plays above the crossover point. If you cross over at 25 Hz, it will play above 25 Hz, just as your speakers will play below 37 Hz (though possibly not at an audible level). The idea is to match the rolloff of the REL with the rolloff of your main speakers. This is done by ear; there is no need to concern yourself too much with the crossover point; I am simply stating that, in my experience, the REL is crossed-over around 25 Hz the overwhelming majority of the time when used with floorstanding speakers. If you follow the setup procedure outlined in our REL Setup guide, you will arrive at the proper crossover point.

Best,

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Comments???

I have heard about some good bass management units such as This one, or, a unit mentioned in this forum as well, Outlaw ICBM. I wonder if they are worth it. Besides, shouldn't I be able to get a satisfying level of bass by the subwoofer alone?

Have you been able to get the sub dialed in to what you think is acceptable? From what I have read on this subject it seems to me Rel flies in the face of conventional thought. If it were me I would try the low level input and crossover the M60s in the 60Hz range. If the 60s are +/-3dB (Hz): 37 - 22 kHz and +3dB- 9dB (Hz): 27 - 22 kHz why would you want to have the crossover at 25Hz. To me it would seem there would be a hole in the lower part of frequencies where the M60s leave off and the Rel (set to 25Hz) picks up. If you can try to do some frequency sweeps and see what you come up with

I hate to play devil's advocate here, but I think Rel is advising the right thing for a pure music system. No matter how much I tweak the crossover freqs and sub levels, I still prefer the sound when I have few crossovers as possible between me and the music. Parking the subwoofer down at where the main speakers roll off does the least "messing around with the sound" and would probably be my preference for music.

Trouble is that for some reason I also much prefer movie playback with a traditional HT setup -- 80 or 100 Hz crossover, speakers set to small, bass management via the receiver, yadda yadda.

Don't write off what Rel is saying, but as everyone else on the board is saying remember it isn't the only way to operate; try 'em both and see which you prefer.

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Parking the subwoofer down at where the main speakers roll off does the least "messing around with the sound" and would probably be my preference for music.

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My question would be, what good does it do to set the crossover so low (25Hz) when the M60s are only rated down to 37. Would it not be better to set the crossover to a setting that would be before the 60s starts to roll off.

It looks like the Rel instructions advise to set the LPF to a very low value (22 or 25 Hz) and work your way up from there. Just guessing.. .agree that 25 Hz is probably way too low for most mains including M60s.

If you want to read something else and still be confused, I offer this detailed, encouraging but still confusing review :

http://stereophile.com/subwoofers/1004rel/index1.html

I read the Stereophile article and there was nothing there to expain the "why" such a low setting. It was not a very informative piece.

Agreed. I was surprised how such a seemingly well written article could be no help at all.

Starting from a very low crossover setting, around 25 Hz and moving up until finding a desirable level makes a lot of sense. In fact that is exactely what REL manual suggests. However, REL distributor clearly states that:

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in my experience, the REL is crossed-over around 25 Hz the overwhelming majority of the time when used with floorstanding speakers.

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That is the part that I don't understand. I tried it yesterday at around 25: you could hear the sub when increasing the high-level volume knob all the way up. However it sounded a little weird, and kind of out of phase. I'll give a few more hours (days) at that setting.

I was reading the owners manual and it states the in room response for the 150 as -6db @ 19 Hz. On the Rel site it says the frequency response for the 150 is 30 to 100 Hz. It looks to me that the 150 will not have very much info when set to 25 Hz. So if these are the correct specs why in the world would they tell you to set the crossover @ 25?


BTW what type of music are you listening to?