Do I really need a sub?

ScottishAndy

Active Member
Hiya!

Am currently building my first Home Cinema set-up. I've already decided on either the MA RS5s or the MA BR5s for the fronts, MS 906s for rears (I already own these), and am yet to decide on a centre.

It's quite a small room (3m wide X 5m long), so I was wondering whether I really needed a sub, at least to begin with.

Sorry if this is an unbelievably dumb thing to ask, but i'm new to all this fun :)

Grateful for your suggestions.
 

Crustyloafer

Distinguished Member
The short answer to your question is yes. There are very few, if any, domestic speakers on the market at all that can deliver bass low enough and without distortion that a decent subwoofer can do.

The only loudspeaker that have have direct experience of, in my demo room and at Metropolis Studios in London, that can be comfortably used without ever feeling the need for a subwoofer are the PMC BB5-XBD professional active studio monitors which retail for £38,000 a pair.

A pair of good quality but low cost floorstanders such as the RS5s or BR5s will serve their purpose well as front speakers but would not be capable of taking on the role of replacing a subwoofer.

That said, there would be no harm in starting without a subwoofer and then adding one when funds allow. Once you get a decent sub you will wonder how you managed for so long without one though.
 

ScottishAndy

Active Member
Thanks very much for clearing that up!

I think I will go for the MS 3091 once I get some more coppers together.

Thanks again.
 

iainsilvester

Active Member
You should also bear in mind that you should only have one bass radiator in your array, so if you have a sub you should set your LCR to "small". A good sub is better at handling low colouration bass than the bottom end of a typical floorstander, and integrating multiple bass radiators in the average room is problematic. This is why THX specifies an 80Hz crossover for all surround speakers with the sub handling everything <80Hz from all channels.

This of course begs the question of why you want large front speakers, and there are plenty of reasons why you don't, but that is another discussion topic:)
 

summerWhine

Standard Member
I see the point of needing to set your LCR to small as integration may be a problem. But, many people use their fronts for 2-channel stereo too, so they still need a decent pair of large(ish) speakers.
 

Sonic67

Banned
I put my system together using 5 largish speakers as I thought I wouldn't need a sub as I'd get enough bass from the rest of the set up. Then one day I was feeling flush and bought one. Wow! Trust me if you want real floor shaking, trouser flapping bass then yes you do.
 

Helicon

Banned
There you go - Sonic67 is living proof!

Regardless of how big your speakers are, they will still need a sub. Floorstanding or large speakers will give you more bass, but that bass isn't necessarily that much lower than standmount or smaller speakers. Initially they're fine, but once a sub is added, you'll hear what you've been missing straight away.

Like Crusty, i've heard a speaker that needed no sub - the Dynaudio Temptation from their Master series. But then at £22k, it's to be expected.
 

Mr_Sukebe

Active Member
The short answer to your question is yes. There are very few, if any, domestic speakers on the market at all that can deliver bass low enough and without distortion that a decent subwoofer can do.

Hey, nothing like a spot of debate.
I'm going to answer that you can do without a sub, though the real answer should be "depends". Here's a few reasons:
- I've yet to hear a sub that can integrate really well with a pair of loudspeakers and provide the coherence across the frequency range that a well designed pair of speakers can. Most result in bass that doesn't mate well with the existing loudspeakers, resulting in a sound that can give the impression of two stereo systems happening to play the same track in the same room, sometimes resulting in timing issues. This is one of the reasons why very few high-end stereo systems use subs.
- You're splitting funds. What I mean by that is that most normal individuals have a budget, lets say £1000 for their speakers. If you assume you need a sub as well, and it has to come from the same budget, you're probably going to spend £500 on the sub, thus reducing the available budget for the speakers by 50%. I assume that it's pretty obvious that speakers costing half the amount, really aren't going to be able to compete with the £1000 pair. Now you can of course say "ah, but I've added all this extra bass", which is maybe another couple of octaves. However, you've also compromised the rest of the frequency range above the bass area, as the more expensive stereo speakers should be better across ALL of their frequency range. So yes you'll have more bass, but things like voices and other instruments will sound worse.
- It's partly dependant upon the source. Whilst some films have some very low bass, very little music (excluding some dance stuff and church organs) will really make use of frequencies down to 20hz. So for the majority of music, your sub won't be doing very much.

Having said all of that, a normal pair of speakers won't go as deep into the bass region. Which compromise would you prefer?

My personal view is that you keep spending money on the best loudspeakers you can, until you find a pair that you prefer to anything else on the market (which will almost certainly cost into the £thousands). Then when you're comfortable you've got the best for yourself, add the best sub you can afford when you have the budget.
 

Helicon

Banned
I agree that in a 2 channel system, subs are best left out of the equation, unless someone's after mega bass on a budget. But in a 5.1 situation, things are a little different. I used to own Kef Reference 4.2's, which when listening in 2 channel, there was no need for a sub. But even with 2x10" internal bass drivers pumping away in a 95 litre enclosure each, a sub was still needed for full effect.
 

iainsilvester

Active Member
The problem is stereo speakers are designed for music, much of which (ie rock) is not particularly dynamic and has no deep bass. The London Philharmonic Orchestra will blitz any U2 concert for dynamics and bass extension, and this is why HiFi has always really been about classical music.

Special effects and dynamics of an action movie are also way more demanding than your average rock track and you need speakers able to handle this. It really is horses for courses. If you want the full movie experience you need a sub, and if you have a sub you don't need large speakers and so a sub/sat (not lifestyle) will win every time, IMHO.

I have 27 yr old stereo speakers too - for music.
 
P

Peter Galbavy

Guest
I didn't see it mentioned, but the other benefit of a sub is to take load off your power amp. An active sub will have a dedicated amp that will be about the same power rating as your normal one - and AFAIAA low frequencies require more driving power for the same sound pressure, this will let you send more "useful" wattage to your normal speakers.
 

Sonic67

Banned
Yes in terms of music a sub doesn't add a lot. It's a gimmick in the same way that dancing LEDs on a stereo is a trick. If you are listening to a classical piece avoid. On the other hand if your music is booming reggae then maybe.

For home cinema it's a much bigger issue. I love it when you are watching a trashy movie full of explosions and rumbles and the sub has something to do.

I was watching 'Constantine' last week and at one point Mrs Sonic67 says "I felt that through the floor!" Still not as funny as when she ducked from a swinging anchor in the rear left speaker during "The Perfect Storm" though.
 

J80FAB

Active Member
Since a thread has appeared about subs & speakers was wondering if some kind soul could answer a question I have.

I did ask this in a separate thread a week or so ago but never got an answer :(

I just have a basic Yamaha amp & speaker package. These are the speakers :

http://www.yamaha-uk.com/pdf/product_bulletins/NS-P110.pdf

I was thinking of upgrading to these for a few reasons & they fit into my budget aswell as going with the Yamaha amp :

http://www.yamaha-uk.com/pdf/product_bulletins/SP Package 125.pdf

I was wondering if the NS-P125 speakers would provide better sound reproduction over the NS-P110 package & if it would be possible to add the sub from the latter package to go with the NS-P125 speakers.

Would prefer to swap the sub over rather than having to buy another.

Also the thing is my amp has a number of settings for speakers. As the NS-P125 are 'bass reflex' would I be wanting the bass to be set to go to all speakers including the subwoofer or just to the subwoofer :confused:

There's also a setting for speaker size. I would imagine that this should be left at 'SMALL' as I guess 'LARGE' is meant for much bigger speakers :confused:

Thanks
 

Sonic67

Banned
"Small" and "Large" are I think down to whether you think the speakers are capable of handling bass. If set to "Small" I imagine the amp sends most of the lower frequency stuff to the sub. If set to "Large" then it sends only the very very lowest frequency stuff.

This is a mixed bag. If only the very low stuff is coming out of the sub it doesn't matter. If you are including the lower end of the mid-frequencies then sounds you expect to come out from around the room are now coming out of the sub.

On the other hand to get good bass you need large speakers. If your five speakers are really small and are getting frequencies they can't handle well, then the sound will sound awful.

Make a decision as to what you think they can handle or try both settings and watch the same bit of a film. Something with a lot of frequencies perhaps. How about Amadeus?
 

AngelEyes

Distinguished Member
Hey, shocking idea but how about we answer the ops question about his HOME CINEMA SETUP rather than try and rehash the endless debate about 2.0 versus 2.1 for music.... :suicide:

Adam
 

J80FAB

Active Member
"Small" and "Large" are I think down to whether you think the speakers are capable of handling bass. If set to "Small" I imagine the amp sends most of the lower frequency stuff to the sub. If set to "Large" then it sends only the very very lowest frequency stuff.

This is a mixed bag. If only the very low stuff is coming out of the sub it doesn't matter. If you are including the lower end of the mid-frequencies then sounds you expect to come out from around the room are now coming out of the sub.

On the other hand to get good bass you need large speakers. If your five speakers are really small and are getting frequencies they can't handle well, then the sound will sound awful.

Make a decision as to what you think they can handle or try both settings and watch the same bit of a film. Something with a lot of frequencies perhaps. How about Amadeus?


I'm not a speaker nor audio expert, so I would just be 'upgrading' to the speakers I mentioned in my previous post as these would fit the budget, are fine in the looks department & go with the amp from the same manufacturer. Just want to keep it straight forward.

In the current set-up with the NS-P110 speaker package sonically performance is very acceptable & the sub does an admirable job taking into consideration how much amp + speakers cost.

I just wanted to know if there would be a general improvement in audio quality with the 5 speakers from the NS-P125 series as they are a bit different from the NS-P110 series. And by keeping the sub from the latter to go with the 125s to complete the job.

I guess the 'SMALL' & 'LARGE' speaker settings might be a case of trial & error to see what the results are.
 

Mr Incredible

Distinguished Member
Just to add my $0.02.......

The combination of my speakers and room size means that with room modes my floorstanders have been measured (Radioshack meter and REW) at 22Hz @ 80db when doing a 75db sweep through the frequencies.

On the face of it this suggests that a sub is superfluous, but as these "lower" frequencies are produced with much more room interaction than at higher frequencies, these lower frequencies appear to be uncontrolled, for want of a better expression. Boomy, is another expression which comes to mind.

Most discerning sub owners will tell you that EQ'ing of the sub is essential to get the best result. As EQ'ing of low frequency producing mains speakers is not as easy to achieve as with a sub, EQ'ing of a sub appears to be the best way to get control of those (troublesome) frequencies below the 80Hz suggested crossover.

I've recently bi-amped my fronts speakers which give them even greater capability to more easily produce the low frequencies. However, it is clear on auditioning music (Blue Man Group!!) with low bass content, that the best overall sound is when I have the (EQ'd) sub in play with the speakers set to small with 80Hz crossover.

A bit a ramble I know, but just because speakers can go low, IMO the impact on the lower frequencies by the smaller-sized home cinema room is significant enough as to require EQ'ing of the those frequencies. This is easily achieved with a sub in place with EQ .
 
F

fullthrottleric

Guest
^^^Well said^^^ :thumbsup:

Lets say you have a 5.0 setup with all speakers capable of unlimited extension/power handling, you now have 5 sets of room EQ to sort out.

Keeping all the really low stuff out of the main speakers will sound much cleaner too as you're reducing dopplar distortion on the higher frequencies handled by the main speakers woofers. Also with reduced excursion each driver will stay closer to the flat part of it's BL curve, reducing distortion.

I'm guessing that most of the people who are saying a sub doesn't add anything to music havn't heard a system with clean output into infrasonics. Likewise to the poster who said you might only be gaining a couple of octaves, thats a lot. Going from 10Hz f3 to 40Hz f3 (two octaves) is like cutting your high frequency extension from 20Khz to 5Khz.

A sub adds loads to the (noisy lol) rock/metal music I like, it gives it a realistic impact and dynamics thats mostly missing on systems with limited low end extension :smashin:

There's no replacement for Vd in producing accurate; linear bass, which usually means large cone area. Something you'll find few domerstically acceptable main speakers have.
 

iainsilvester

Active Member
Quote : This is a mixed bag. If only the very low stuff is coming out of the sub it doesn't matter. If you are including the lower end of the mid-frequencies then sounds you expect to come out from around the room are now coming out of the sub.

I think this misunderstands the psychacoustic properties of surround sound. The issue is not whether a surround speaker can produce bass, it's whether it needs to. Assuming the boys at THX aren't stupid, their basic requirement for 1 bass radiator and crossover at 80Hz should mean something.

The whole point of surround sound is to position sound in a 3D stage around the listener. You cannot position sounds that have no directional perception for us humans. This is <80Hz at the most, and probably more like 150 Hz. With bass limited surrounds you can then have perfect matching of tonal responses because you can have identical speakers, particualrly the LCR. And you only have integrate 1 bass speaker in your room, the sub. For movies it is the best way to do surround sound, and movies are what surround was designed for.
 

Member 96948

Distinguished Member
Hiya!

Am currently building my first Home Cinema set-up. I've already decided on either the MA RS5s or the MA BR5s for the fronts, MS 906s for rears (I already own these), and am yet to decide on a centre.

It's quite a small room (3m wide X 5m long), so I was wondering whether I really needed a sub, at least to begin with.

Sorry if this is an unbelievably dumb thing to ask, but i'm new to all this fun :)

Grateful for your suggestions.
Nobody actually needs as sub, but there are some very good reasons for wanting one.

1. I'll get this out the way: Buy the matching MA center speaker. Anything that doesn't match will stick out a bit and ruin the coherance of action across the front.

2. All other specious arguements aside, in a home cinema steup, if you don't have a sub, then you are throwing away the entire .1/LFE channel in Dolby Digital. DD, in it's wisdom, decides that the LFE channel is too bassy and dynamic to redistribute back to the main speakers. There is also some dynamic range compression applied which will quite literally compress noisy peaks by 3-6dB.

3. Regardless of the size of your main speakers, diverting the bass from the mains to the sub will give the AV amp and speakers an easier ride. The benefits, will be a more relaxed sound due to greater headroom and assuming you end up with a good sub, lower distortion bass which as it now only comes from one box, will be easier to tune optimally to suit the room.

Now the above is less clear cut in a mega-bucks system/2 channel system/hybrid, but it is correct for a solid budget setup like yours.

Russell
 

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