Question about using floorstanding speakers with a sub

mva5580

So I have RTi 12's, and I have them setup to be "small" since I have a Polk DSW Micro Pro 660 sub. I guess my question lies in wondering whether or not my rather large RTi 12's are really being used to their fullest in this kind of configuration? I mean looking at it, the RTi 12's have 3 subwoofers built into them. If I have these speakers setup to be small, does that essentially mean that the tweeter/mid-range are really all that's being utilized and the subs are somewhat dormant? I know there is a crossover which I have thought to mean that the subs do have some stuff going through them, but am I right in thinking that a rather large part of my rather large floorstanding speakers really aren't being used?

I guess part of the reason why I ask this is that I've been entertaining the thought of going to bookshelf speakers in my living room, and if a significant part of the floorstanding speakers aren't really even being used, it may accelerate my decision. I do a little bit of everything with these speakers; music/movies/gaming/tv. TV doesn't really bother me either way because I usually tend to be underwhelmed at compressed TV audio.

Mystery

Try different combo.
1. Like you have now.
2. Set fronts as large but send LFE to sub only.
3. Set fronts as large and send bass to both sub and fronts.
4. If you really want to limit fronts, send speaker out from amp/receiver to the sub and then speaker out from sub to the speakers.

See what works best.

If you have a good pair of bookshelves and a sub, they can easily match floorstanders.

tonyb

Personally, I've never been a big fan of setting large floorstanders to small. Set them to large and see if your receiver allows for the double bass in it's settings.

Curious as I am, why buy such nice speakers if all your doing is compressed TV audio ?

mva5580

tonyb wrote: »

Personally, I've never been a big fan of setting large floorstanders to small. Set them to large and see if your receiver allows for the double bass in it's settings.

Curious as I am, why buy such nice speakers if all your doing is compressed TV audio ?

It's not all I'm doing, I just meant it as I'm not as concerned about the speaker settings either way while I'm watching TV because the streams are all over the place in terms of their "quality." Sometimes the audio from the center speaker is really faint, sometimes it's really loud, sometimes the audio that should be coming from the center comes from another speaker, etc. I'm not saying it's constant, just that TV audio isn't any kind of factor in a decision for me.

amgala

Many people caution against "double bass" because in some cases the low frequency output from the speakers can cancel out the output from the sub. So, you may end up with a hole in that spectrum. Or, where they overlap, the bass can get overpowering. Read this from the Audyssey 101 thread on AVSForum:

What is ‘LFE + Main’ or ‘Double Bass’ and should I use it?

The short answer is ‘No’ – you should not use these settings and, if you have a subwoofer, you should never set your speakers to ‘Large’. For the more detailed reasoning behind this, read on…

Denon units have a setting called ‘LFE + Main’ and Onkyo units call this ‘Double Bass’. They both set out to achieve the same thing. Before we look at the issues surrounding these settings, we need to clarify what your AVR manufacturer means when they say speakers are ‘Large’ or ‘Small’.

For starters, these designations have nothing whatsoever to do with the physical size of your speakers. In AVR-speak, ‘Large’ means “no bass management” and ‘Small’ means “bass management is used”. For our present purposes, ‘bass management’ means that you have a subwoofer and you want to send bass frequencies to it – usually all the frequencies below a certain crossover level that you have chosen (or which your AVR has chosen when you ran your Audyssey setup routine). Often this crossover will be 80Hz.

If you set your speakers to ‘Large’ then ordinarily no bass management at all is used. This means that your expensive subwoofer is doing nothing other than handling the relatively small amount of content in the LFE channel (the .1 in 5.1).

If , however, you decide to use a crossover to send the low frequencies to your subwoofer, then you will need to set the speakers to ‘Small’. In some AVRs, you don’t specify ‘Small’ – the very act of setting a crossover means that the speakers have been designated as small.

However… what happens if you set your AVR to use the ‘LFE + Main’ or the ‘Double Bass’ setting?

With Denon units, if you set the mains to "Large" and ‘LFE+MAIN’, the mains will receive the full frequency spectrum, and bass from the main channels will also be sent to the sub (LFE) simultaneously. The same thing happens with Onkyo units if you set ‘Double Bass’. In both cases you are now sending low frequencies to both the main speakers AND the subwoofer. The problem is, this is a really bad idea for the following reasons:

First, there is the possibility of phase cancellation when the main speakers and the subwoofer play the same bass frequencies.

Second, in the region where the frequencies overlap between the subwoofer and the main speakers, the bass frequencies are doubled and tend to become bloated, boomy, and exaggerated.

Also, the XT and MultEQ versions of Audyssey apply more correction filters to the subwoofer frequencies. If the same frequencies are sent to the main speakers and the subwoofer at the same time, you will apply higher resolution filters to the same frequencies in the subwoofer and lower resolution filters to the same frequencies going to the front speakers. When the two low frequency sources are combined, we will have unpredictable results to say the least.

Finally, read what Chris Kyriakakis of Audyssey has to say on the subject:

"LFE + Main should not even be an option because it just causes duplication of bass content by sending it to both the sub and any speakers set to Large (Full Range).

A "high ranking" official in a "well-known" AVR company told me that LFE + Main was invented to appease customers that were upset when their speakers were being set to Small. These customers had a complete lack of understanding of what Small means (i.e. turn on bass management and redirect the bass to the subwoofer) and felt... inadequate. LFE + Main allows them to set their speakers to a more manly Large and still have bass management. But it's a compromise that can cause boomy bass if the speaker and subwoofer overlap in the lower frequencies."

http://www.avsforum.com/t/795421/official-audyssey-thread-faq-in-post-1/51750#user_f7

mva5580

Yeah I mean even without me really knowing a whole lot about it, "double bass" didn't sound like something I would be too interested in doing.

I don't want bass to be overpowering my room, I just want it to be noticeable when it's supposed to be. Which is why I've got myself in this situation of thinking that these big RTi 12's really aren't being utilized in the way they "should " be considering I have them set to small and I'm using the DSW 660 as my sub. I've been entertaining getting rid of the 12's and switching to LSIM 703's for a while now.

Polkie2009

Try setting them to small and setting the crossovers to 80 hz. Let the sub do the heavy lifting of the hz. under 80. I'm not sure what AVR you're running there mva, it may allow you a number of crossover hz. to try , like 75,70,65, 60,55,50,40??? play around with it, see what sounds best in your listening room.

rpf65

If it were me, I would probably set the speakers to small, find which cross-over freq sounds best in all listening modes, with the exception of music. That I would run in 2-channel direct mode, whcih should use only the RTI 12's and ignore the sub entirely. Here I will agree with the 2-channel purists, most recorded music is designed to be played from 2 channels. I don't care if technology is so advanced, and bass non-directional, that I should move into the modern era.

Be it a CD, radio, or old/new records, 2-channel sounds better to my ears. Never heard SACD, but concert DVD's sound better in multi-channel modes, but those are exceptions.

The 2-channel area is what you want,and paid for those sub woofers in your 12's.

Don't misunderstand me, the choice of you keeping or replacing your speakers is irrelavent to me. What's important in that matter is your ears, available space, and/or spouse approval.

Syndil

Your RTi12s have a -3db lower limit of 26Hz, the sub has a -3db limit of 25Hz, so... It gives you an extra 1Hz, and that's only if your room is an anechoic test chamber.

So, regardless of where you set your crossover, your fronts could handle whatever you are sending to the sub. In your case the most logical setup would bet to set your speakers to large, and set the sub to LFE only.

You might even get a wild hair up your rear and try having your AVR mix the LFE in to your front channels, and take the sub out of the picture entirely. Just something else to try.

tonyb

I understand your thoughts on double bass being overpowering but maybe that's the wrong terminology. What I meant was to have the fronts to large and still use the crossover to blend so the sub only plays the lowest of notes. Not double frequency coverage which is what double bass would elude to. My bad I guess, but many receiver manuals refer to double bass which if you do it right and the receiver allows, doesn't have to be double the frequency coverage. In other words, use more of the speaker and less of the subwoofer. By setting to small, most receivers have pre determined frequency responses in that setting, limits if you will. If you set to large and use the LFE, you can have the sub kick in where those low notes on the speaker start rolling off. Essentially the speakers will handle a broader range of the bass notes while the sub will handle more of the hard hitting lower notes.

Now of course we run into the argument of what can handle bass notes better, a speaker or a sub, and there is no correct answer. Every room/ear/gear is different to make that call. The old set to small, crossover at 80 is a starting point, not written in stone. So we are left with the proper blending of the sub and the front speakers and there's more than one way to skin that cat. A little trial and error is needed at times to find what your systems capabilities are.

mva5580

Syndil wrote: »

Your RTi12s have a -3db lower limit of 26Hz, the sub has a -3db limit of 25Hz, so... It gives you an extra 1Hz, and that's only if your room is an anechoic test chamber.

So, regardless of where you set your crossover, your fronts could handle whatever you are sending to the sub. In your case the most logical setup would bet to set your speakers to large, and set the sub to LFE only.

You might even get a wild hair up your rear and try having your AVR mix the LFE in to your front channels, and take the sub out of the picture entirely. Just something else to try.

So if I were to do that I guess my next question would be is the sub even necessary? Is it handling enough information in that setup to even justify having it?

And let's compare a bookshelf (LSIM 703 for example) + DSW 660 setup to RTi 12's set to large (or small even) and sub. Is it a fair assumption to make that the 703's + DSW 660 may not quite be as good of a bass combination as the other, but the rest is going to be an upgrade? And if the answer to that is yes, is it fair for me to say as someone who does not really look for bass to completely overpower the room, that the 703 + 660 combo may end up being an upgrade in quality for me personally?

tonyb

mva5580 wrote: »

So if I were to do that I guess my next question would be is the sub even necessary? Is it handling enough information in that setup to even justify having it?

Try it both ways, only you can determine that. The advantage the sub has is it's own power amplifier where as the speaker uses a shared power supply. This will result in quicker transients of the lower notes, a quicker start and stop if you will, more dynamic.

Perhaps Syndil was eluding to the sub being on the light side for your speakers.

pearsall001

Here's just two of many great articles on the subject, http://www.ecoustics.com/articles/set-speakers-small-receiver-setup/. http://ultrafi.com/why-everybody-needs-a-good-subwoofer/ Without a doubt the subwoofer has earned it's shoddy reputation over the years as being simply a large "boombox" but now the tide is turning with the excellent subs that are now available. Now partner the sub/subs with a top notch EQ program & look out!!! There is no speaker that can compete with a dedicated quality sub let alone a matched pair, plain old physics & science at work here. Your speakers will thank you, your amp will thank you, your room acoustics will thank you & best of all your ears will thank you when you hear the revelation of the new sound now coming from your speakers.

Conradicles

You can read all the articles and take all the advice you want and that is good.

Try different settings yourself and make the decision.

Syndil

mva5580 wrote: »

So if I were to do that I guess my next question would be is the sub even necessary? Is it handling enough information in that setup to even justify having it?

As others have said, only you can determine that. It depends on many factors, such as room acoustics, the quality of your gear, etc. But it is possible that your fronts may handle LFE bass better than your sub. It certainly isn't a predetermined conclusion that a dedicated sub will always work better than having the fronts do the same work. In your case, your fronts have roughly twice the surface area dedicated to reproducing bass than your sub does. I think the deciding factor will be the quality of the amp you are using to drive the fronts.

Mystery

mva5580 wrote: »

Yeah I mean even without me really knowing a whole lot about it, "double bass" didn't sound like something I would be too interested in doing.

It's not like you have to spend a grand to try double bass.
You already have large fronts and a sub so don't dismiss it without even trying it.
I know fellow audiophiles who tried different combinations and settled on sending bass to both fronts and sub and that sounded much better with smoother bass/low transition than cutting off low bass frequency on the fronts.
So try different settings and settle on what works best in your room.

Chas

This posting I have just read has answered so many of my unanswered questions. Thank you so much. Please continue with this level of post. Thanks.
Chas

Polkie2009

Hey Chas, welcome to CP, glad this forum has helped you. How do you have your speaks set up large or small, crossovered at? hz.?