|   what if ? | skh
Jan 7, 2003 11:38 PM | | Would a person gain anything if he ran the speaker wire from receiver to bare wire terminal on a small sub and out of sub to surround speaker do it on both sides so you would have three sub one up front and one on each surround speaker i know on a 5.1 set up bass comes through the LFE channel but i just was wandering if you could get a litte something out of the surround channels say in a war dvd or action dvd One more ? when you go though the bare wire terminal of a powered sub do you bypass the amp in the sub and it is powered by the receiver then Thank you |
| re: what if ? | kfalls
Jan 8, 2003 5:58 AM | | It's my understanding in Dolby Digital and DTS the surrounds are full-range, so as long as they are set to "large" not all the bass will be on the LFE channel. It would be overkill to have two subs in the rear since one powered sub is capable of providing both channels and would reduce the possibility/probability of standing waves within the room. Output for the rears will be supplied from the receiver, bypassing the subs amp. I have full-range surrounds in my main system and can testify there is plenty of bass in the rear channels. On the "Band of Brothers" DVDs I hear the bombs dropping all around me with more than adequate realism.
My System:
Legacy Focus mains
Legacy Silver Screen center
T&A P-30 3-way 12" surrounds
Denon AVR-3300 HT receiver
Lexicon CP1+ processor (for music DSP)
Pioneer 414 DVD
Yamaha M-65 (drives the 6-12" Focus woofers)
Pioneer Pro-100 RPTV |
| re: what if ? | Bryan
Jan 8, 2003 7:45 AM | | You would probably get between 6 - 12dbs but you would also experience some frequency cancellation in the process. Easiest thing to do is set all speakers on small and let the receiver handle the crossover to the sub. |
| It is my understanding... | jeskibuff
Jan 8, 2003 8:30 AM | | ...that a powered sub can take input from EITHER line level (RCA) inputs or speaker-level inputs, if equipped with them. You're calling the speaker-level inputs "bare wire", if I'm reading you correctly. Regardless of the input, I'm certain that the amplifier in the sub will be driving it. Speaker-level inputs are just cut down or "attenuated" and fed to the sub amplifier. This is why it's better to use line inputs rather than speaker-level inputs. Your receiver has already amplified those signals, adding coloration and distortion, however small. By attenuating them and reamplifying them, you're just adding more processing artifacts to the signal. Now whether the sub is smart enough to select one input over another if you feed it signals on both sets of inputs or whether it combines ALL signals fed to it is probably determined by the design of the sub itself. I would (as has been stated in earlier responses), let your receiver do the balancing act rather than inundating the subwoofer with a mishmash of incoming signals. Feed it with just the line-level output from your receiver and I think you'll get the best out of it. Make sure your receiver settings are optimized for your speaker setup and you won't have to artificially create more impact for your war movies. |
| It is my understanding... | Quagmire
Jan 9, 2003 12:06 AM | | "You're calling the speaker-level inputs "bare wire", if I'm reading you correctly. Regardless of the input, I'm certain that the amplifier in the sub will be driving it."
Yes, this is correct. If the sub is a "powered" sub and not "passive" then the sub's amp will power the speaker in the sub regardless of whether it is fed a line level or speaker level signal. It may be that the best results can be achieved by using a standard 5.1 setup and allowing the receiver to provide bass management: Placing multiple subs in a room without creating various undesirable anomolies can be a daunting task unto itself, but I'm on record in the past for always encouraging folks to experiment and decide for themselves what sounds best. If he can borrow a sub or buy one with little risk from a store with a liberal return policy, I say... give it a whirl. Hopefully, he'll do us a favor and come back to let us know how things turned out. In this way, the one who asked the question will end up educating the rest of us. Nice post, jeskibuff!
Q |
| re: what if ? | Wyatt_
Jan 8, 2003 10:59 AM | | Don't do it.
The output from the receiver to sub is low, low, low wattage and can't drive alot(assuming the receiver is designed to output to a powered sub). So if you hook it from the sub then the receiver might effectively be driving another speaker. That speaker won't have enough power and components in the receiver might start heating up. Additionally the output to the sub may be pre-filtered, containing only low frequency stuff that only another sub could appreciate. |
| re: what if ? | Quagmire
Jan 9, 2003 1:11 AM | | Wyatt,
If you want to speculate about things of this nature for your own purposes, fine. But when these kinds of unfounded speculations are presented in the form of firm advice then it begins to border on irresponsibility. Receivers don't drive "powered" subs, "powered" subs drive themselves and do not create an increased load on the receiver. The only increased load would be caused as a result of the receiver passing full bandwidth information to the surround speakers instead of redirecting the low frequency information of the surround channels to the sub preout jack; but this would occur whether one placed a sub in line with the surrounds or just used large full range speakers in the surround locations instead.
It is a normal wiring configuration (among many) for most subs to be connected at speaker level between the amp source and the "satalite" speakers. This creates no risk of damage to the sub, the receiver, or the speakers. Also, the only way that the output of the sub would be "pre-filtered" would be if it were connected to the receiver's normal sub preout - the speaker level outputs of the sub itself would never be pre-filtered as you suggest. And besides, getting away from sending the surrounds low frequency information to the receiver's sub out is precisely at the heart of his question.
It's fine for him to try this setup; he may find that he is not able to achieve the results he's looking for or expects, but the sub in line with the surround speakers presents no risk to his equipment.
Q |
| re: what if ? | kfalls
Jan 9, 2003 6:14 AM | | Excellent post, very well presented! Accurately and thoroughly covers the issue. |
| re: what if ? | Harinder
Jan 9, 2003 10:12 AM | | Yes you can do it, but make sure you are using another Sub for this. You can't use same sub though. If you want you can even add one sub to each of five speakers, but it would not help or improve much, because sound engineers who put 5.1 channel sound, program movie sound for one sub out, and your LFE (low frequency effect) signal is actually separated by your receiver. If you are using LFE sub out from your receiver you need to set your speakers to SMALL under settings on your receiver, or if you got some nice big speakers, you can leave it to LARGE. Small speaker setting filter low frequencies from all five speakers to LFE to your SUB, and Large speaker settings send the whole signal to speakers. In simple wordings if using Small speaker settings use LFE or sub out of your receiver, for Large speaker setting run speaker wires usually front left and right to Sub, and then connect speakers from SUB. Your main speakers still be power by receivers output, and what sub's circuitry do samples the incoming signal filter it to low pass and high pass, keep the low pass for SUBWOOFER and pass on other frequencies typically above 150HZ to speakers. In some subwoofer you can adjust this frequency though. Sometime you can adjust LFE on receivers as well depends on if your receiver has this functional setting. Hope I answered your question, and made it clear as mudd!!! |
| re: what if ? | Harinder
Jan 9, 2003 10:23 AM | | Or put two cannons next to surround speakers for more realistic boom!!!! JUST KIDDING |
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