JAKEETON Posted January 10, 2012 Share Posted January 10, 2012 Hello Everyone I just ordered the RW-12D sub.Presently I have a 12" JBL sub Im using.I always hear that having two subs is a plus.I was curious if anybody had any thoughts on using these two subs together.Im guessing it's not ideal,but still a worthwhile task?I thought I could put the JBL in the rear of the room.I assume I would just connect with a Y adapter and run the calibration on my Marantz?Is it hard to get the proper sound with two subs?Any advice or tips would be great. Quote Link to comment Share on other sites More sharing options...
wuzzzer Posted January 10, 2012 Share Posted January 10, 2012 Its difficult enough to balance two identical subs in a room, let alone two completely different ones. Best bet would be to sell the JBL and pick up another 12d. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 10, 2012 Share Posted January 10, 2012 For those running two subs, do you run one left and one right? or do you run left and right to both subs and adjust the placement in the room? Just curious? May seem like a dumb question, but i think there might be more than one way to achieve dual subs? With my KPT684 i had the option of bridging the subs, or running them independantly. i bridged them... Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 11, 2012 Share Posted January 11, 2012 For those running two subs, do you run one left and one right? or do you run left and right to both subs and adjust the placement in the room? On most pre-pro's and receivers, there's just one sub (LFE) out. You split the signal from there. I've never seen a LFE track that has 2 distinct (L andR) tracks. As far as where to place them after the signal is split goes, that's very room dependant. If you co-locate them you can get a good 3-6 dB gain over seperate placement. If you spread them out, you can sometimes achieve a little better response in a broader area of the room than with one. It does however require a lot more set up time to get non co-located subs to work correctly. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 11, 2012 Share Posted January 11, 2012 Instead of using the LFE out, could you use the pre left out to one sub, and pre right out to the other. and use the xover from the Crown XTI1000(only an example) as the band pass? Then you would have independant subs? Just wondering? Then you may not need to mess around with placement as much, as they would be left and right? Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 11, 2012 Share Posted January 11, 2012 Instead of using the LFE out, could you use the pre left out to one sub, and pre right out to the other. and use the xover from the Crown XTI1000(only an example) as the band pass? Then you would have independant subs? Just wondering? Then you may not need to mess around with placement as much, as they would be left and right? The Crown would need to have a high pass filter. In addition, if you were using the subs for HT, you'd loose the entire LFE (.1) track by wiring that way. You also would have no phase adjustment (critical for setting up non-colocated subs). The problem with dual subs isn't the signal they receive. It's the fact that, depending on placement, they can cancel each other out to the point where you actually have less SPL at the listening position than when you had one sub. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 11, 2012 Share Posted January 11, 2012 If you have your sub connected to the LFE port, How does that LFE port work with Music? I have an have always had my Sub connected to the Left and Right either at wire level or pre level... I've never used the LFE port. you know, im Just sitting here thinking...i should have known this, but no one has ever told me different??????[:$] Quote Link to comment Share on other sites More sharing options...
sivadselim Posted January 11, 2012 Share Posted January 11, 2012 In addition, if you were using the subs for HT, you'd loose the entire LFE (.1) track by wiring that way. If you have an AV receiver or processor you CAN wire a sub (or subs) to the left and right channels if you desire. You just need to setup the AVR or processor as having NO SUB so that the LFE channel info (when there is LFE channel info) will be rerouted into the L and R channels in the appropriate measure.But doing so wouldn't really be useful in helping to navigate the issues involved with running dissimilar subs. If you have your sub connected to the LFE port, How does that LFE port work with Music? With 2-channel sources? If the front speakers are set to SMALL, the bass below the crossover setting will be rerouted to the subwoofer. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 11, 2012 Share Posted January 11, 2012 IF you have a receiver or pre-pro that can redirect the LFE chanel to the mains, I wouldn't do it. Sending info below 20 Hz to your mains is a recipe for disaster. If it goes to the pre-outs, it'll go out the speaker wires also. Quote Link to comment Share on other sites More sharing options...
sivadselim Posted January 12, 2012 Share Posted January 12, 2012 IF you have a receiver or pre-pro that can redirect the LFE chanel to the mains, I wouldn't do it. Sending info below 20 Hz to your mains is a recipe for disaster. If it goes to the pre-outs, it'll go out the speaker wires also. All AVRs and pre/pros can redirect the LFE channel to the main channels. And they WILL do that if configured as having NO SUB connected. Good idea? Depends upon your exact situation, goals, speakers, and listening habits. I currently have no sub and have my AVR configured as such and have no qualms at all about sending the LFE channel to my mains. None at all. A properly and well-designed speaker, even a small speaker, will not just "up and die" when sent the LFE channel. Of course, a healthy dose of common sense is needed. But you don't commonly see the recomendation to falsely configure an AVR as having a subwoofer connected even when it doesn't have a suvbwoofer connected. That setting (NO SUB) is there for a reason.But we're off-track, here. It's not really relevant to the OP's post. Quote Link to comment Share on other sites More sharing options...
sivadselim Posted January 12, 2012 Share Posted January 12, 2012 Is it hard to get the proper sound with two subs?"Proper"? Yes, with two dissimilar subs it usually IS hard. How hard? Depends upon how much effort you want to put into it and how "proper" you want it to be. Assuming that Audyssey is what you will be using to EQ, yes, that can help, depending upon which version of Audyssey you have. But you will still need to adjust each sub's individual level and phasing, properly, prior to running Audyssey. And simply level-matching them may not be the best tactic. It might take a bit of trial and error, but the goal would be to have to apply as little EQ with Audyssey as possible. It is doable and you might even be able to use the two subs to your advantage, but it's not really something you can just "plug and play". Not if you want it done "proper". Quote Link to comment Share on other sites More sharing options...
JAKEETON Posted January 12, 2012 Author Share Posted January 12, 2012 I will utilize a SPL meter and hopefully get decent results.I suppose measuring the subs in test mode would be the best way to go. Quote Link to comment Share on other sites More sharing options...
willland Posted January 12, 2012 Share Posted January 12, 2012 Is it hard to get the proper sound with two subs? ]"Proper"? Yes, with two dissimilar subs it usually IS hard. How hard? Depends upon how much effort you want to put into it and how "proper" you want it to be. Assuming that Audyssey is what you will be using to EQ, yes, that can help, depending upon which version of Audyssey you have. But you will still need to adjust each sub's individual level and phasing, properly, prior to running Audyssey. And simply level-matching them may not be the best tactic. It might take a bit of trial and error, but the goal would be to have to apply as little EQ with Audyssey as possible. It is doable and you might even be able to use the two subs to your advantage, but it's not really something you can just "plug and play". Not if you want it done "proper". What he said. After many weeks of placement changes and tweeking phase, crossover, and gain(on sub, X-30, and receiver), I was pretty darn successful with incorporating a Paradigm Servo 15a with my existing Klipsch RSW-10d. The RSW-10d handles the midbass down to around 24Hz and the Paradigm gets the sub 35Hz duty down to about 17Hz. Loud, fast, and deep with no boominess at all, IMO and others that have heard it. If you do have some sort of EQ software(which I did not), I suggest you use it to shorten the time and effort to get it right. Bill Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 12, 2012 Share Posted January 12, 2012 I currently have no sub and have my AVR configured as such and have no qualms at all about sending the LFE channel to my mains. None at all. A properly and well-designed speaker, even a small speaker, will not just "up and die" when sent the LFE channel. I wouldn't think it would "up and die", but I can't see how sending a signal an octave or two below the tuning frequency of a speaker would be good for a speaker (just the opposite), but you are correct, I'm off track (BIG surprise there). Quote Link to comment Share on other sites More sharing options...
sivadselim Posted January 12, 2012 Share Posted January 12, 2012 ................but I can't see how sending a signal an octave or two below the tuning frequency of a speaker would be good for a speaker (just the opposite)...................You realize that there can be quite a bit of very low-frequncy info encoded even in the main channels of many movies' soundtracks, right? Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 12, 2012 Share Posted January 12, 2012 ................but I can't see how sending a signal an octave or two below the tuning frequency of a speaker would be good for a speaker (just the opposite)...................You realize that there can be quite a bit of very low-frequncy info encoded even in the main channels of many movies' soundtracks, right? Yes, that's one of the reasons I set my speakers to small and use a sub. Quote Link to comment Share on other sites More sharing options...
psg Posted January 13, 2012 Share Posted January 13, 2012 I would be VERY surprised if rerouting LFE to main speakers doesn't engage some sort of Dynamic Range Control (i.e. midnight mode) to severely limit the LFE sent to the mains. Heck, even if you have a sub, setting the center to off (phantom mode) usually engages DRC and robs you of 5 to 10 dB of dynamic range. Otherwise the L+R channel preputs could clip easily with the 10 dB headroom that LFE has over other channels. Try it! I did with a DVD Dolby Digital track a decade ago and setting the center to off reduced overall peaks by 7 dB on the few movies I tried (with the dialog set to the same SPL). Quote Link to comment Share on other sites More sharing options...
sivadselim Posted January 13, 2012 Share Posted January 13, 2012 Yes, that's one of the reasons I set my speakers to small and use a sub. Well, yeah, of course. But for someone who has no subwoofer and who follows their AVR's instruction manual and/or uses Audyssey, MCACC, or YPAO to calibrate/EQ their setup, the NO SUB setting IS what is going to be used.I would be VERY surprised if rerouting LFE to main speakers doesn't engage some sort of Dynamic Range Control..........I am pretty certain that it does not. I think that it may be reduced by 3dB and then split across the front channels. This has been visited before in some other AV forums. Yes, 'no center' engages DRC.But that the LFE channel is not attenuated in this circumstance would only serve to support an argument that it shouldn't be rerouted to the mains. Still, you will never see an instruction manual mention 'tricking" an AVR into having a sub connected in order to keep the LFE channel from being rerouted. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 13, 2012 Share Posted January 13, 2012 A quote from THIS article. Once the high- and lowpass filters are in place, and all the bass has been directed to the appropriate speakers, the bass peak-level limiter takes over to prevent bass from being distorted, even at high volume levels. Because of the proliferation of limiters in powered subwoofers, not all AV controllers include limiters, but they are often found in THX-certified controllers. The function of the limiter is to prevent the controller from outputting a voltage level that would overload the main speakers or subwoofers that are connected to it (see Fig. 5). Limiters are typically provided for the subwoofer output, but some controllers also include limiters for the main speakers in the event that there is no subwoofer and the LFE channel and bass from small main speakers is routed to other main speakers. Quote Link to comment Share on other sites More sharing options...
sivadselim Posted January 14, 2012 Share Posted January 14, 2012 An AVR (or processor) can be configured as having NO SUB and the soundtrack can still be reproduced exactly as intended. Yes, this includes the LFE channel. Configuring an AVR (or processor) as such doesn't impose any sort of DRC, no info is dropped, and the level of the LFE channel that is mixed into the front channels is not reduced. The AVR doesn't know the capability of the speakers connected to it. Of course, whether the speakers can reproduce what they are sent is another issue altogether. Quote Link to comment Share on other sites More sharing options...
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