Large vs. Small Speaker Setting in HT Setup

[Adz]

In this month's edition of Widescreen Review there is an article in which the writer/reviewer sets out some pretty good arguments as to why speakers should in fact be run full range (large setting) if at all possible in a home theatre setup to maximize sonic performance. The article starts on page 40 but the relevant text starts on the bottom of page 48.

Here is one quote from this article: ["If the loudspeakers around you are not substantially full range, you’ll run into several problems, and you won’t hear accurate bass, and you won’t get the full benefits of surround bass. For example, if you cut off the bass to all the surrounding loudspeakers, or if you use small loudspeakers that can’t reproduce bass in the first place, then you’ll have to electrically mix the bass from all channels to send it to the subwoofer (and also mix it with the LFE channel if present). But electrically mixing bass from plural channels tends to cancel out bass energy, due to phase cancellations, so you won’t be hearing full bass energy, nor will you hear accurate bass reproduction (since this phase cancellation continually varies over time, thereby artificially modulating and pumping the original bass sounds in and out at random)."]

In the very least, the reviewer advocates setting the speakers to small with a crossover set to 40 Hz. Check it out.

[Paul H]

[QUOTE=Adz]Here is one quote from this article: ["... But electrically mixing bass from plural channels tends to cancel out bass energy, due to phase cancellations, so you won’t be hearing full bass energy, nor will you hear accurate bass reproduction (since this phase cancellation continually varies over time, thereby artificially modulating and pumping the original bass sounds in and out at random)."]


Substitute the word "acoustically" for "electrically" above to get an explanation of what happens assuming that all speakers are capable and set for fulll range.

Paul

[Aussie Geoff]

Hi,

I have read this argument before. I have no doubt that it is correct in systems with 5 or 7 full range speakers. However there are other, equally compelling articles about the strain that deep bass puts surround speakers (usually 2 way) dring to drive their 4-6 inch cones to do deep bass, expecting that the surround processor will have redirected it to a subwoofer... For example the THX standard that many mixing studios use (certified or "defacto") has bass mixed away from all the speakers (especially the sourrounds) bellow 80 Hz...

So - bottom line - some years ago I experimented with my system and my ears - and I found that (just like the books said):
1) At 80 Hz or below you can't localise where the bass is comming from
2) All my speakers (even the large 30 Hz cutover front left and right) sounded better treated as small with 80Hz crossover.
3) Sub placement is critical to avoid room modes etc.
4) Setting all speakers to full range reduced the clarity of the midrange and the overall system defintion in my case.

I seriously expect that unless people have very poweful amps and high quality speakers - setting at least the surrounds to SMALL wiht a crossover at least 20 Hz above their minimum will be better for most people...

Bottom line though - people should listen for themselves and decide - it is an hour ot two very well spent...

Geoff

[number17]

This is a pretty worthwhile discussion IMO, as I've been struggling with the similar issue recently.

I have a 5.1 setup with JM Lab Chrous series. The manufacturer recommends to set all speakers to LARGE, saying "their speakers have a wide enough range and nicely constructed filters to enable the best audio experience under the LARGE setting". This would mean setting the CC (spec'ed to go down to 50Hz) and satellite L+R (down to 60Hz) to LARGE.

I have played with different settings and I notice when I set all the speakers to SMALL, I am losing some details, especially in the low end. It is, however, true that I hear less noise in the low end, especially in those 'noisy scenes' where there are multiple layers of sound at different frequencies. There does seem to be clearer seperation between high-end, mid-range and low-end with the SMALL setting.

Conversely when I set everything to LARGE as per the manufacturer's recommendation, I hear more details, but it is indeed noisier in the low end.

My ears tell me I prefer the everything in LARGE setting than everything in small, but it could also be a case where I'm used to the former. I am going to spend more time listening to both configurations.

I also tried setting everything to SMALL except for the F L+R speakers (which are towers spec'ed to go down to 45Hz) to LARGE. It seems to be the best of both worlds thus far.

I don't know if setting the crossover freq to 40Hz actually does anything ... the HPF of the speakers will have cut off the frequency long before that, and the only thing you may gain is you're saving a bit of power of your receiver. But, 40Hz is still pretty low so I don't know if it actually saves much, especially if you have some easy to drive speakers to begin with.

I think it depends on the speakers and personal preference, but it's an interesting discussion to see what ppl's experiences are with both settings.


#17

[ajpoe]

I agree fully with that article. I had a .1 sub until I heard my buddy's Athena SCT series system. I was so amazed by the amount of low effects that came from the rear channels and the ability to localize each channels low effects, so much so that I replaced my .1 sub with the same 4 powered subs that he has. I already had a Paradigm Studio set up so the subs were all I needed. I basically blended a P3 into each of my 60s and a P2 into each of my ADPs to create 4 full range speakers and run them as large. It sounds so much more realistic IMHO. I have also read that bass can be localized above 50 hz, not 80 hz, but I have never tested it side by side on my own. I do know that with explosions and things of that nature, I can tell where it is coming from. I run my Studio CC-470 full range as well because I feel that voices sound more realistic.

ajpoe

[Clive]

.................So are we saying here that size matters? If your speakers are say small <cubes> can they be also set to large? Will we be asking for trouble over time? I know someone will say "upgrade" but for the sake of those members who may not have high end speakers/equipment.

Recomendations

[number17]

I don't think LARGE or SMALL refers to the size of the speakers (or speaker enclosures) I think it refers to the frequency range of the speakers.

Large tower speakers may have a narrow frequency range while small satellite speakers may have a wide range ... though that's normally not the case.

[Bam!]

...thing is you need a pretty heft built speaker to be able to set your pre pro to large...I set my Pro ac 2.5's to large and they almost went caploweee in LOTR...so back to small they go!

[brucek]

The question of large vs small has little to do with the speakers you are using - it is really a question of whether you want to let your processor take care of bass management or not.

Personally, I think it's a good idea to let the processor take care of this as long as you have a decent subwoofer.

I have a set of mains that are in the $11K range, and I would certainly consider them as full range. But I set them to small when it comes to HT because I feel the processor can handle the bass management properly.

When I switch to 2 channel, of course I run my mains full range - that's what two channel is all about...

Paul H and Aussie Geoffs post say it all.... :T

brucek

[Adz]

Personally, I think it's a good idea to let the processor take care of this as long as you have a decent subwoofer

.


While the staff writer at Widescreen would disagree with you, I suppose it comes down to preference / what sounds better in one's particular system (assuming that the system has full range speakers to begin with).

[Azeke]

I have been experimenting with this very issue for a while. Here are my speaker freq ranges:

Speaker freq range (front): 30Hz-20KHz
Speaker freq range (center): 38Hz-22KHZ
Speaker freq range (rear): 38Hz-30KHz
Speaker freq range (cb): 45Hz-30KHz
Freq Range (sub): 18Hz-100KHz


After experimentation with large and small, I have the following settings:

Front: Small Xover:60Hz
Rears: Small Xover:80Hz
CBacks: Small Xover:80Hz
Center: Small Xover: 80Hz
Sub: Xover: 80Hz

Thusfar, this sounds very good to me, however I am still tweaking (go figure).

I am always open to suggestions, but this is what works best for me.

Any comments or suggestions are welcome.

Regards,

Azeke

[Aussie Geoff]

Azeke,

My settings too - 80Hz for everything but the mains at 60Hz. I suspect 50 Hz would be good too for the mains but only have 40 Hz as the next option and that is too low...

Geoff

[Azeke]

Azeke,

My settings too - 80Hz for everything but the mains at 60Hz. I suspect 50 Hz would be good too for the mains but only have 40 Hz as the next option and that is too low...

[B]Geoff[/B]

Indeed Geoff, I tried 40Hz for the fronts, and I agree it was too low.

Regards,

Azeke

[ekkoville]

What is the reason for the settings small and large if you can easily tweak the crossover. It seems crossover points every 5-10 Hz would be more customizable. If I set the speakers to large and select a crossover to 60 Hz, I have just changed the so-called large setting, what is the point?

[Aussie Geoff]

Ekkoville,

Great question and this confuses a lot of people. The term SMALL and LARGE dates back the the original Dolby Pro-Logic and THX days where people were happy with a fixed 80 Hz crossover and SMALL just meant that a small spaker (for example rear speakers were always SMALL). However with the advent of 5.1 sound with separate subwoofer channels and serious bass rediection process the term SMALL really means "BASS REDIRECT TO THE SUBWOOFER" with the Crossover frequency as set (e.g 80 Hz, 60 Hz etc) making it usual practice to (in HT mode at least) run even full range spakers as SMALL just with a lower crossover than the surround speakers...

Unless you have amazing speakers or speakers with built in or slaved subwoofers - you can usually get extra bass by redirecting at some point - 20Hz, 30Hz etc... Even big speakers like B&W 802's benefit hugely in being crossed over to a sub at arround 40 Hz or so in a HT environment where there is lots of bass energy happenning.... Hence some posts about people slaving subs off all their speakers (nice if you can afford it and fit in in your room and pass the WAF test!)

Geoff

[ekkoville]

I agree Geoff, which brings me to another question, and that is before the dedicated LFE and redirecting of bass, people would use bookshelf style speakers and run them with a full range signal and have no ability to redirect bass. It seems that some are worried more now than ever about sending a full range signal to a pair of speakers that can handle signals down to 40Hz. why so much attention given these days and not much concern in years past? The signal is always been the same, no real difference in music. HT is a different story though, much more dynamic material better left to a piece of equipment, i.e. sub, to do the work.

Erik

[Aussie Geoff]

Ekoville,

Good analysis -which is why many modern processors (like the RSP-1098 ) allow you to vary the speaker bass processing for stereo vs HT - so you can select SMALL or LARGE or vary the corssover freqency to send full range (or closer to full rnage) to the speakers for stereo while haveing bass processing at (say) 80 Hz in place for HT.

I have to say though - with a nice tight subwoofer operating with a speaker - the extra depth and atmosphere you can get is amazing - even classics like "A Bridge Over Troubled Water" can be just transformed!

Geoff

[Kevin P]

I agree Geoff, which brings me to another question, and that is before the dedicated LFE and redirecting of bass, people would use bookshelf style speakers and run them with a full range signal and have no ability to redirect bass. It seems that some are worried more now than ever about sending a full range signal to a pair of speakers that can handle signals down to 40Hz. why so much attention given these days and not much concern in years past?

In years past (in the days of ProLogic), most people didn't have subwoofers in their systems. So the only place to send the bass was to the main speakers.

With the advent of Dolby Digital, DTS, and home theater in a box solutions, subwoofers have become the norm rather than the exception in even entry-level home theaters. Since any well-matched sub will go deeper than even the main speakers, there's less loss of bass information if you set the speakers to "small".

I for one have towers that can easily go down into the mid 30s. Even my center and surrounds reach 40 easily. I run them all small, with an 80 Hz crossover, and let my SVS handle bass duties, since it can go an entire octave lower than my speakers.

The exception is when I listen to CDs or SACDs, where I use analog bypass. This also bypasses the bass management so I get a full range signal to my mains. I like the way this sounds in my system, and it eliminates the need to turn on the sub when listening to music. Most music doesn't go much lower than 40 Hz anyway, whereas action movie soundtracks often go far deeper in their LFE tracks.

[ekkoville]

I guess with the options of subs and bookshelf speakers or towers we have just about as much flexibility as ever, you ought to use them. Thanks guys.

Erik

[number17]

Lots of good points here ...

I got a quick and stupid question.

Movies that are 5.1 encoded, whether DD or DTS, already have a subwoofer 'track' (thus the ".1").

So when you set your speakers to SMALL, and direct the bass from the L+R speakers (I don't believe CC usually carries much bass) to the subwoofer, what does the processor do with the bass from the 3 different channels (L, R, and sub) ?

Does the processor simply 'add' them together and feed everything to the sub?

What if the bass aren't completely in phase and you end up with destructive interference, which cancels the bass?

And, in that case, aren't you better off with the subwoofer just outputing the sub track from the DVD, which is what is intended?

I can understand if you have a stereo track or a 5 channel track it makes sense to direct the bass to the sub. But when you already have a sub track to begin with (the ".1" part of the DVD audio) I'm confused what really happens when you have the bass managment directing bass.

[ajpoe]

That's a good question, I believe the freqs cut from all channels go to the .1 sub on top of the LFE channel that is already present. I am not neglecting the LFE channel because I am running my TST only off that channel. I figure the really low effects are the only ones I want to feel in the TST and that works best for me. The .1 channel was designed for systems that can't handle full range all the way around so a system that can is ideal IMO. When I used to have a .1 sub, I ran my speakers as small and had the TST on the LFE with the sub. The low freqs from music soundtracks etc were all sent to the TST which I did not like. Since I have set everything as large, ONLY the effects (no music) gets to the TST which is a much better movie experience. Bass from music and directional effects now come from sub for whatever channel it should or all in large explosions or effects all around you while still shaken by the TST effects at the same time.

[Adz]

I have my three front speakers set to Large
Frequency Response L&R 11Hz — 30 kHz
Frequency Response Center 19 Hz — 30 kHz

These speakers can go very low with built in 1800 watt amplifiers. I don't run the LFE into them since it seemed to cloud the highs and mids. So, I run the LFE into an external passive subwoofer which is behind my couch. I run the rest of my three surrounds set to small with a crossover set to 80.

Now these surround speakers all have 6.5 woofers and can go down to 22 hz.
So after reading the article, I tried it and frankly didn't like it. I also tried small but with a crossover of 40. I found in both cases that it weakened the overall bass in the system, so I am just leaving them on small with 80 crossover for now.