Do I want/need a Subwoofer/Sub if the frequency range is covered by my floorstanders?

Wavod

Active Member
Hi,

My Surround Speakers are as follows :

Make/Model Frequency Range

KEF iQ9 (Fronts) 38-40,000 Hz

KEF iQ6c (Centre) 65-40,000 Hz

KEF iQ8DS (Rears) 65-40,000 Hz

KEF 30B (Sub) 40-150 Hz

My question is that as the iQ9 Fronts go down to 38 Hz will having the Sub (which starts at 40Hz) be of any benefit apart from adding more bass somewhere else in the room?

Also any other advice/upgrade suggestions to match my set-up would be appreciated (setting Crossover levels etc.) Thanks.
 

Badger0-0

Member
It's difficult to say what it would be doing in your room.
If it's in a different place from the speakers, it could be reinforcing or killing certain frequencies.
You wouldn't know without seriously looking into it.

One thing seems for sure though.
Given that Kef's own specs say the 30B is rated down to 45hz @ -3dB, it would seem that using it is possibly a waste of time.
It depends though.

The question would be do you think things sound better when it's on?

If you want to add more weight to the bottom end, for movies in particular, it wouldn't be difficult to improve things.
Most of the BK subs would be superior and even the cheapest, the Gemini, would probably be on a par.

But you should bear in mind that the lower a sub can go, the more issues you can introduce, which means they're no longer "plonk and play".

Well worth the effort though :smashin:
 

Butuz

Standard Member
45hz at -3db is pretty pathetic from a so called sub. Infact in my book 45hz is barely even sub bass.

Still. It's an old sub I suppose. I have an early 90s Tannoy sub lying around that only goes down to 30hz and thats a 12" woofer!!

Most decent subs nowadays can hit 20hz.

So the question is: do you want more high bass? In which case keep your sub. Or do you want lower bass? In which case you need to buy a new sub!

Butuz
 

Badger0-0

Member
I have an early 90s Tannoy sub lying around that only goes down to 30hz and thats a 12" woofer!!
The 30B has a 12" woofer too!
But the amp is pretty puny at 70W.
Must admit I was very surprised at that Spec, but I'd suggest it's designed purely for music and as you suggest, higher bass.
 

cribeiro

Novice Member
You can have a benefit, because you can cut the low frequencies and redirect them to the sub. This way, your speakers will have less hard work to do and can concentrate on mids and highs. They should sound better, specially when pushed.
 

Member 639844

Former Advertiser
Analogy time I think. Its like asking, do I need a BMW M3 when my 20 year old austin metro can do 70 mph anyway. Both have you covered for crusin the highway, but the experiences are very different. 30hz from a good subwoofer is likewise a different experience than the same from a subwoofer.

As already noted, your speakers will sound clearer as well when you add in the sub, so its well worth the addition of a good sub in any system.
 

filterfreak

Novice Member
in my newby opinion your mains only go down to 38hz ,now do you want to hear bass ? do you want to feel bass ? a subwoofer is only a reinforcement for low frequencies ,i personally would not use an av setup without a subwoofer and that sub would have to reach below hearing range 20hz .yep i would get a sub for your speakers otherwise your missing out on what the directors and producers of the films really wanted you to hear and more important "feel"!
 

Inx8

Standard Member
Can I ask you good people a stupid question : Why do most of us have a sub AND floorstanders. Even when you go buy a 5.1 setup it includes floorstanders most of the time.
 

cribeiro

Novice Member
Can I ask you good people a stupid question : Why do most of us have a sub AND floorstanders. Even when you go buy a 5.1 setup it includes floorstanders most of the time.
See #5 here ;)
Besides, Floorstanders have nothing to do with frequency response. Yes, a bigger cabinet allows for deeper bass, but you can find beefy standmounts with more grunt than flimsy floorstanders.
 

Wavod

Active Member
You do need a sub, you could just do with a better one than that one.
To be honest, you have confirmed my suspicions about the 30B. Although a very capable sub in it's day (I believe at that time the world was 2.1 if I remember rightly!) I think we have now moved on and I am now 99% going to upgrade to a BK Monolith when/if I can.
Do you suggest this will be the way to go, or should I go down to a smaller sub considering I enjoy both music and movies on a regular basis in a regular sized living room (20ft x 15ft) in a Semi-Detached house ??
All views welcome on this topic to secure a satisfactory outcome :clap:
 

Badger0-0

Member
or should I go down to a smaller sub considering I enjoy both music and movies on a regular basis in a regular sized living room (20ft x 15ft) in a Semi-Detached house ??
A Monolith would be fine and I wouldn't consider anything less in a room that size.

I run an SVS Ultra in an 18ft x 9ft room and it isn't too much ;)
 

gstriftos

Novice Member
.1 is a discreet channel.Meaning it has content that needs to be directed to a dedicated speaker(sub).
Sure some AVR's have the option of sending LFE channel to your main speakers but that would kill em.
 

gstriftos

Novice Member
You know what I mean by ''kill em''...
Most loudspeakers aren't capable of handling the LFE content correctly.
Well it's logical since they don't have monstrous speakers nor are fed by really hefty amps.
DRC compresses if I remember well,so what's the point?
 

Member 639844

Former Advertiser
You know what I mean by ''kill em''...
Most loudspeakers aren't capable of handling the LFE content correctly.
Well it's logical since they don't have monstrous speakers nor are fed by really hefty amps.
DRC compresses if I remember well,so what's the point?
The LFE channel can be upto 10db hot. If a person had no sub then a response down to 80 only would be no good, so they have to be catered for. With no sub present, the LFE content is sent back to the speakers, just not at the increased levels they are for the subwoofer. This helps protect the speakers somewhat and allows people without subs to hear all the material. Obviously, people with tiny speakers will pretty much always have a sub, but people with larger speakers might not. Some people dont like the change in sound their speakers suffer when they remove the sub 8-hz material, so they might make use of the double bass option etc.
 

gstriftos

Novice Member
Another thing taking into consideration is the difficulty of calibrating sub 80Hz frequencies when not using a sub.
 

cribeiro

Novice Member
Another thing taking into consideration is the difficulty of calibrating sub 80Hz frequencies when not using a sub.
:confused:
Actually, bass going to two floorstanders placed symmetrically will sound better than from one subwoofer in a corner (assuming no EQ).

If you have Audyssey MultEQ XT, it will calibrate with or without sub anyway.
 

Member 639844

Former Advertiser
Another thing taking into consideration is the difficulty of calibrating sub 80Hz frequencies when not using a sub.
:confused:
Actually, bass going to two floorstanders placed symmetrically will sound better than from one subwoofer in a corner (assuming no EQ).

If you have Audyssey MultEQ XT, it will calibrate with or without sub anyway.
If you had multi input speakers too, and Bi-amped them, you could also driver the bass drivers as though they were subs if you had an AVR or some kind of dedicated HT processor (pre/pro) at the helm, and use something like Audyssey to eq them that way. Audyssey uses more filters for the sub channels so it would essentially improve the eq applied to help out with the bass in a system set up that way, i.e someone with out a sub but running large speakers.
 
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cribeiro

Novice Member
If you had multi input speakers too, and Bi-amped them, you could also driver the bass drivers as though they were subs if you had an AVR or some kind of dedicated HT processor (pre/pro) at the helm, and use something like Audyssey to eq them that way. Audyssey uses more filters for the sub channels so it would essentially improve the eq applied to help out with the bass in a system set up that way, i.e someone with out a sub but running large speakers.
You won't believe it, but I actually thought about doing that with the AS-EQ1 :suicide: Unfortunately, the woofers covered up to 1500Hz or something like that, which was too high for the AS-EQ1.

It is indeed a good idea if you have large speakers and do not want to use the "large" setting of the processor/AVR to avoid DRC.
 

Member 639844

Former Advertiser
You won't believe it, but I actually thought about doing that with the AS-EQ1 :suicide: Unfortunately, the woofers covered up to 1500Hz or something like that, which was too high for the AS-EQ1.

It is indeed a good idea if you have large speakers and do not want to use the "large" setting of the processor/AVR to avoid DRC.
Its such a shame these devices arent a little more manually configurable. It would be nice to set a desired working range to eq, and then have the option to augment the end response curve if you wished. Surely those 2 options wouldnt be that hard to include for enthusiasts.
 

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