a question about low freq.

[dtel]

If I set my main's to large on reciever and send the lfe to both the sub and mains , what happens when a movie has much lower bass than what the main speakers can handle.

I had always had the main speakers set to small, and when i put the forte ll in place of the sb3 i wanted to try them on large setting. i must be missing something very simple

[DrWho]

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On 6/8/2005 10:43:15 PM dtel wrote:

If I set my main's to large on reciever and send the lfe to both the sub and mains , what happens when a movie has much lower bass than what the main speakers can handle.

I had always had the main speakers set to small, and when i put the forte ll in place of the sb3 i wanted to try them on large setting. i must be missing something very simple

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Setting to large just means the crossover is bypassed. In other words, setting it to small means the speaker only recieves signals about the crossover point (ie signals above 80Hz). Signals too low for the speakers will introduce distortion due to extra cone excursion. However, most manufactures design loudspeakers such that low notes are just relatively quieter and therefore the cone excursion is controlled (so not as much extra distortion, but there's still more).

However, the subwoofer itself is going to introduce distortion as well and sometimes it is beneficial to have the mains and sub playing at the same time (overall it takes less cone excursion for each speaker in order to achieve the same SPL).

Distortion aside, the room itself and the positioning of the speakers usually plays a bigger role in deciding whether or not to use sub + mains setting. Having 3 different sources playing the same signals can cause comb filtering or other annoying things. If you're lucky sometimes the phase issues will counteract the room's issues and leave you with a better sound. Btw, I know that I'm way oversimplifying this.

In the end, it's really easier to dial in the system just using the normal subwoofer setting and not trying to deal with the extra headache that the sub+mains can introduce. If nothing else, just switch between the different modes and pick for yourself which you like better. You should have no fear of hurting your mains as their cone excursion is very well controlled below the F3 point (not to mention the F3 is like 35Hz or something like that for the forte).

[dtel]

Thanks DR it sounds better set to large on just the mains.

I just diden't want to cause a problem for the forte, just was not sure about movies, music don't go that low. thanks for the answer

[sivadselim]

you can't send the LFE to the mains with a sub set to ON in any configuration. if the sub is set to ON, all LFE goes to the sub, regardless of the "LFE+Main" setting.

an "LFE+Main" setting duplicates the bass info below your crossover setting from the left and right main channels at the sub, NOT vice-versa. LFE doesn't go to the mains. LFE will never be rerouted by the receiver to both the mains AND the sub. what IS rerouted by the receiver and duplicated at both the sub and mains with a LARGE and "LFE+Main" setting is standard front L+R bass that's below your receiver's xover setting.

now, what you CAN do is connect a sub via speaker-level connections and instruct a receiver that there is NO sub, and get LFE spread across both the sub and the mains.

regarding your question, if the mains are set to LARGE, whether you're using the "LFE+Main" setting or not, and the movie's left and right channel(s) contain(s) "much lower bass than what the main speakers can handle", then they simply shouldn't be set to LARGE, but SMALL instead.

[dtel]

It's a yamaha reciever rxv 740, for the speaker setting it ask sub ,main,or both i had always used sub before but the forte ll went much lower so i tried it with music and it sounded better < had rechecked the phase and crosover first>. Movies go much lower though, diden't want to break something

I think the crosover is at 100 and can't be changed on this yamaha,not that that would help for my question.