# Large vs. Small



## nova (Apr 30, 2006)

So, as I sit, surf, and listen (on my secondary system) I wonder about all the pundits who recommend you always set your speakers to small. At low and very moderate volumes does it really matter? I mean, really, 65 dB??? how much distortion and/or whatever can there possibly be?


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## MACCA350 (Apr 25, 2006)

nova said:


> So, as I sit, surf, and listen (on my secondary system) I wonder about all the pundits who recommend you always set your speakers to small. At low and very moderate volumes does it really matter? I mean, really, 65 dB??? how much distortion and/or whatever can there possibly be?


Here are some sonograms that will explain why you should use 'small' if you have a sub in your system. 

The sonograms show bass information below 60Hz for all six Dolby Digital channels separately, taken digitally off the relevant DVD. Basically this is what is actually recorded on those channels.

*ID4 scene at the start where the ship passes over the moon*









*WOTW lightning scene, all of chapter 4*








*
WOTW emerging scene, all of chapter 5*









As you can see there is heaps of bass in the other channels, and in many cases there is actually lower and more bass in them compared to the LFE channel. If you set those channels to 'large' and they cant reproduce those fq then its lost. Not only that but your expecting those speakers to handle information down to 0Hz and if they don't have a subsonic filter to protect themselves then they will try to produce those Fq's and in doing so draw large amounts of current from your amp leaving less headroom for those Fq that they can adequately produce. 

IMHO, if you have a sub then USE IT and crossover your other speakers depending on what they can actually do(not just what the specs say). If you don't have a sub then you've got no choice.

cheers


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## nova (Apr 30, 2006)

For those who do not know, my secondary system is my PC set-up; Sony STR-DE995, Lite-On DVD/CD ROM combo, Karajan audio on DFI LP NF4 SLI-DR, 4 RBH MC-4C, 1 RBH MC-414C, and an RBH TS-10AP sub.

I rarely watch a movie with this set-up, so I was really thinking more along the lines of just music. I don't know if these speakers have a subsonic filter, I'd think with the high quality components used in the RBH speakers there would not be a problem. So are you saying that at low volumes they will still draw large amounts of current?

I usually have them set to small, but occasionally I'll set them to large while listening to music,....I also always use the sub. Unfortunately this Sony does not let me adjust the crossover, I believe it is set to 80, my speakers OTOH are good to about 95-90 (85 published) so it seems to my ears, to sound better when set to large, as they try to fill in the hole. Make any sense? :scratch:


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## SteveCallas (Apr 29, 2006)

> Unfortunately this Sony does not let me adjust the crossover, I believe it is set to 80, my speakers OTOH are good to about 95-90 (85 published) so it seems to my ears, to sound better when set to large, as they try to fill in the hole. Make any sense?


Yes. If your speakers aren't flat until well below 80hz, then the natural rolloff of the speaker will combine with the 4th order rolloff of the 80hz crossover. It's now no longer 4th order like it should be, but 8th if it's a ported speaker and 6th if it's sealed, and there will still be an additional dip from 80-95hz that won't be accounted for. By not using the 80hz crossover in the chain and still using a sub, you're coming closer to what the original 80hz crossover SHOULD have looked like, so FR should be smoother from say 40-100hz as compared to using the 80hz crossover. Some quick measurements with RoomEQ should confirm this.


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## MACCA350 (Apr 25, 2006)

nova said:


> Unfortunately this Sony does not let me adjust the crossover, I believe it is set to 80, my speakers OTOH are good to about 95-90 (85 published) so it seems to my ears, to sound better when set to large, as they try to fill in the hole. Make any sense? :scratch:


Let me get this straight, your speakers are good down to 90 and your receiver's crossover is 80, then the crossover is below the point that your speakers start to roll off(which means that the crossover _may_ not be effecting your speakers output at all(I'm not sure I understood SteveCallas conclusion). If this is the case then the main difference between the 'large' and 'small' setting for you is:

'large'= your sub gets none of the information from those channels and those channels can't reproduce it anyway, so it's gone(unless you use 'double bass' or LFE+MAIN feature, which means the sub will get the information)

'small'= your sub gets the information from those channels below 80Hz(which your speakers may not be reproducing anyway)

So basically you cant fill that hole(if there is one) between 80-90(you'd need to use REW to really know what is actually happening, you may have placement or phase issues) UNLESS you use the speaker level outs from the receiver to the sub and use its crossover(if it has more adjustment than the receiver) and then run from the sub to your speakers. 

But at the end of the day, do what you feel sounds the best because ultimately you're listening to it:T 

cheers


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## SteveCallas (Apr 29, 2006)

Yeah, I think I confused myself :doh: You are correct in that if the natural speaker rolloff starts at 95hz, the 80hz crossover shouldn't get to affect it - unless the speakers are sealed. It was said that the sub gets used whether the speakers are set to large or small for music....I wonder what range of a signal the sub is being fed while the speakers are set to large. RoomEQ is our friend :T


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## nova (Apr 30, 2006)

Yes, these speakers are sealed, so how does that affect the natural roll off? And why is there a pronounced difference between large and small? 

Hmmm, also makes me wonder just what info the sub is getting. There is no LFE+Main option, or any thing like it...and off the top of my head I think the only bass management options with this receiver are Large or Small, and Sub=Yes or No. So if I select sub=yes does that mean even if the mains are set to large the sub still gets everything below the assumed 80 x-over?


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## MACCA350 (Apr 25, 2006)

nova said:


> So if I select sub=yes does that mean even if the mains are set to large the sub still gets everything below the assumed 80 x-over?


NO, the sub only gets the information in the specific .1(LFE) channel and the redirected bass from those speaker channels set to 'small'

Have a read through this article

There is another thread on the subject here


cheers


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## nova (Apr 30, 2006)

Well this is where something is different,.... with speakers set to large and no LFE channel, the sub is still getting a signal. Not sure exactly what this Sony receiver is doing, but it definitely is sending something to the sub.


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## MACCA350 (Apr 25, 2006)

nova said:


> Well this is where something is different,.... with speakers set to large and no LFE channel, the sub is still getting a signal. Not sure exactly what this Sony receiver is doing, but it definitely is sending something to the sub.


What do you mean by no LFE channel? What model receiver do you have? Do you have ALL speakers set to large?

cheers


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## nova (Apr 30, 2006)

What I mean by no LFE channel is say, stereo. Even with 2ch content and speakers set to large this receiver (Sony STR-DE995) is sending some signal to the sub. Here is a direct quote from the manual; "However, if there are no low frequency signals (Dolby Digital LFE, etc.) it will generate a low frequency signal for output to the sub woofer" ????? This is what really has me curious,... just what/how is this info generated?


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## MACCA350 (Apr 25, 2006)

nova said:


> What I mean by no LFE channel is say, stereo. Even with 2ch content and speakers set to large this receiver (Sony STR-DE995) is sending some signal to the sub. Here is a direct quote from the manual; "However, if there are no low frequency signals (Dolby Digital LFE, etc.) it will generate a low frequency signal for output to the sub woofer" ????? This is what really has me curious,... just what/how is this info generated?


What page of the manual is that on. Do you know if it refers to a DSP mode?

cheers


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## MACCA350 (Apr 25, 2006)

nova said:


> Well this is where something is different,.... with speakers set to large and no LFE channel, the sub is still getting a signal. Not sure exactly what this Sony receiver is doing, but it definitely is sending something to the sub.


Also did you have the sub set to none in the receiver? 

cheers


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## nova (Apr 30, 2006)

On page 28 of my manual, does not refer to DSP. This is when set to "A.F.D. Auto" AKA Auto Format Direct. This automatically detects the signal and presents the sound as encoded,...except 2CH when it generates it own signal for the sub. Apparently the only time this receiver does not send a signal to the sub is when it is set to "2CH". Or when the sub is set to "no".


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## MACCA350 (Apr 25, 2006)

nova said:


> On page 28 of my manual, does not refer to DSP. This is when set to "A.F.D. Auto" AKA Auto Format Direct. This automatically detects the signal and presents the sound as encoded,...except 2CH when it generates it own signal for the sub. *Apparently the only time this receiver does not send a signal to the sub is when it is set to "2CH". Or when the sub is set to "no"*.


That makes sense, except that it adds bass to the sub when your speakers are set to large(if this only happened if your speakers were set to small, I could understand it). This seems to ignore what bass management you have set up. Do you have a LFE+MAIN or Double Bass feature?

cheers


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## nova (Apr 30, 2006)

Yeah,... Odd huh? Thats what makes me wonder just what signal it's sending and why it seems to sound better when the speakers are set to large :scratch: There is no dbl bass or lfe+main feature.


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## MACCA350 (Apr 25, 2006)

nova said:


> Yeah,... Odd huh? Thats what makes me wonder just what signal it's sending and why it seems to sound better when the speakers are set to large :scratch: There is no dbl bass or lfe+main feature.


In this particular case, I would assume, the only difference between the 'large' and 'small' setting is whether your mains receive bass below the crossover or not since the sub is getting the bass either way. 

cheers


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## Hakka (Sep 10, 2006)

If you tell the AVR you don't have a sub connected, there's no need for it to disable the subwoofer output. Most AVRs I've used do this.


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