aejonesia39
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DefTech 8040ST as upgrade to SM55?
commsysman
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You don't make it clear HOW you are managing the transition from the SM55s to the subwooofer.

If you have not yet done so, try the following-

Set the receiver to "large" for the SM55s.

Connect the terminals of the speakers to the speaker-level inputs on the subwoofer using some speaker wire.

Experiment with raising and lowering the LP setting (subwoofer upper limit frequency setting) until you get the best interaction between the subwoofer and speakers.

I think this will solve your problem, once you find the setting that gives the best subwoofer blend.

aejonesia39
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Thank you for the reply. I am currently following the set up recommended by DefTech. I've got the 55s set as "small" with crossover at 60. I've got the sub set at 80 (unclear to me if this is correct; DefTech says my center (8040HD) should be at 80 and surrounds at 100).

I will try your suggestion. Just so this ultra novice is clear, I'm running a set of speaker wire from receiver F L/R outs to the monitors, then a second set of wires from the monitors to the high level inputs on the sub?

commsysman
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You of course need your main speaker wires from the receiver outputs to the speakers, to drive the speakers.

The wires from the speakers to the subwoofer speaker-level input terminals will carry only a very small current, so they can be 18 or 20 gauge wire; any size is OK really.

Once you connect the sub this way, the receiver setting for the sub no longer has any effect; the LF controls on the sub itself will control it, and should probably be set for between 40 and 50 Hz. Just adjust until it sounds best.

The factory spec sheet says the SM55 goes down to 32 Hz, but in reality I am sure they start to roll off at about 50 Hz.

Setting the rolloff to 60 Hz for them will rob you of their desirable midbass performance, so setting them for full-range is best. Their inherent LF rolloff is all that is required; artificially limiting their performance with a receiver-set limit does not make much sense.

Please try setting them to full-range and see if this does not make your system sound better. I think you will like the result.

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