I'm considering the addition of a subwoofer to my nearfield monitor set, but I'm wondering about the running of such system.
These are the main questions:
Where does the sub get the signal?
and above all
How correctly balance the subwoofer and the nearfield levels, since on that balance will be based the mix eq ?
sub frequencies monitoring
An interesting twist & aspect of this conversation is the fact that one man's ears will monitor bass down to a certain frequency, while another man's may be significantly different & there is no way of measuring this aspect / differentiation.
Another interesting aspect of this conversation would be the fact that the organs, bones, flesh & tissue of your body have different frequency responses to your ears. This is something which I think is shamefully often overlooked in 'dance music'.
Another interesting aspect of this conversation would be the fact that the organs, bones, flesh & tissue of your body have different frequency responses to your ears. This is something which I think is shamefully often overlooked in 'dance music'.
If you decide to add a subwoofer you're going to need to TREAT YOUR ROOM. Simply treating your room might even out your current subbass response enough to make it more workable, but if you add a sub and DON'T treat your low end with proper planning and bass trapping then you're only going to make things even worse.
If you're already sitting in a perfectly flat room that's had proper treatment, ignore my words.
If you're already sitting in a perfectly flat room that's had proper treatment, ignore my words.
My workroom is not acoustically treated and my nearfield set is 'entry level', but I've just had a look thru the manufacturer' site, and a subwoofer unit for those monitors is avalaible. It has L & R inputs and outputs, +/- 6dB trimming (as well as the monitors have themselves), room position compensation, and phase compensation. Regarding the phase compensation setup the manufacturer recommend the use of special devices or, in the lack, the following trick: run a 80 Hz tone thru both the sub and the monitors and find the adjustment by wich the tone can be heard louder.
There's also a footswitch input for A/B comparisons (but it's not specified if a push button like or a switch like device is needed). Usefull to avoid bass lacking mixes while trying to give the right shape to the bottom end.
<font size=-1>[ This Message was edited by: Cochise on 2006-04-21 16:44 ]</font>
There's also a footswitch input for A/B comparisons (but it's not specified if a push button like or a switch like device is needed). Usefull to avoid bass lacking mixes while trying to give the right shape to the bottom end.
<font size=-1>[ This Message was edited by: Cochise on 2006-04-21 16:44 ]</font>
Using a single tone to set your speaker phase & position is also a bad idea. The resonances you will have are caused by room nodes and simply changing a single semitone or moving 6" to the side will completely change the way the room reacts.
There are quite a few pieces of software on the net to calculate room nodes for at least the first 5 or 6 harmonics based on simple rectangle room dimensions.
Realtraps has a decent overview on the situation, although they try to sell you their products at the same time of course.
There's also a decent discussion in the pdf on this page, on page 7 under the "Standing Waves" section.
This guy gives you the extreme end of room isolation & treatment, definately overkill for just adding a sub but some might find it interesting to read.
I think harmony central might have a decent section on this too, I know sospubs.co.uk does, and there are a few places on the net that give decent home-made methods to basstrapping.
<font size=-1>[ This Message was edited by: valis on 2006-04-22 04:00 ]</font>
There are quite a few pieces of software on the net to calculate room nodes for at least the first 5 or 6 harmonics based on simple rectangle room dimensions.
Realtraps has a decent overview on the situation, although they try to sell you their products at the same time of course.
There's also a decent discussion in the pdf on this page, on page 7 under the "Standing Waves" section.
This guy gives you the extreme end of room isolation & treatment, definately overkill for just adding a sub but some might find it interesting to read.
I think harmony central might have a decent section on this too, I know sospubs.co.uk does, and there are a few places on the net that give decent home-made methods to basstrapping.
<font size=-1>[ This Message was edited by: valis on 2006-04-22 04:00 ]</font>
You can also find out just about everything imaginable related to room accoustics & acoustic treatment at <a href="http://www.johnlsayers.com/phpBB2/index ... ers.com</a>
studio design forums. It's the same link as the one in the 'build your own basstraps' thread I posted here in off topic a week or so ago.
Those forums are worth visiting if you're even remotely interested in studio accoustics.
studio design forums. It's the same link as the one in the 'build your own basstraps' thread I posted here in off topic a week or so ago.
Those forums are worth visiting if you're even remotely interested in studio accoustics.
That about sums it up Braincell. The only way a studio making electronic music to be played in clubs & on big sound systems can get anywhere near close to simulating the desired bass experience they need for their end listeners is to include a sub woofer & crank up the volume. 
As Valis quite rightly points out though, it would be a bad idea in a small home studio or control/tracking room to include a sub without accoustic treatment. Properly adding a sub to your room for bass monitoring would need at least bass trapping & full spectrum floor to ceiling panel absorbers should probably be added if you're going that far. But bass traps and other room treatments are probably well worth the effort if you're serious & have the right enviroment to set it all up & listen at high levels.
We can't turn the volume levels up high enough where we stay to justify it at the moment though & most of our serious monitoring is done on big assed headphones.
As Valis quite rightly points out though, it would be a bad idea in a small home studio or control/tracking room to include a sub without accoustic treatment. Properly adding a sub to your room for bass monitoring would need at least bass trapping & full spectrum floor to ceiling panel absorbers should probably be added if you're going that far. But bass traps and other room treatments are probably well worth the effort if you're serious & have the right enviroment to set it all up & listen at high levels.
We can't turn the volume levels up high enough where we stay to justify it at the moment though & most of our serious monitoring is done on big assed headphones.
Very usefull links and comments for any possible future development of my activity.
At present I operate in my bedroom
and there are forniture like wood closets making the acoustic worse with their resonance.
For sure, listening at low levels, we have less sensitivity for bass frequencies (hi-fi amplis have loudness button for that), so istinctively compensating, the mix tend to become boomy.
Halveing the listening distance is possible to get just those +6db spl...
The need of a subwoofer for me, born also from the lack of bass deepness I have listening contemporary music through my nearfields, in comparison with the same music listened thru 2.1 PC speaker system, with similar volume.
At the low end of the audio frequency band, human hearing has not that very subtle discernment for different freqs, so talking about shapeing might be excessive. The real matter is leveling.
How can I correctly level frequencies below 60Hz (supposing that I succeed in achieve them tracking) if I can't hear them?
I've just to cut them off.
<font size=-1>[ This Message was edited by: Cochise on 2006-04-22 09:46 ]</font>
At present I operate in my bedroom
and there are forniture like wood closets making the acoustic worse with their resonance.For sure, listening at low levels, we have less sensitivity for bass frequencies (hi-fi amplis have loudness button for that), so istinctively compensating, the mix tend to become boomy.
Halveing the listening distance is possible to get just those +6db spl...
The need of a subwoofer for me, born also from the lack of bass deepness I have listening contemporary music through my nearfields, in comparison with the same music listened thru 2.1 PC speaker system, with similar volume.
At the low end of the audio frequency band, human hearing has not that very subtle discernment for different freqs, so talking about shapeing might be excessive. The real matter is leveling.
How can I correctly level frequencies below 60Hz (supposing that I succeed in achieve them tracking) if I can't hear them?
I've just to cut them off.
<font size=-1>[ This Message was edited by: Cochise on 2006-04-22 09:46 ]</font>
That was part of my train of thought when talking about our bodies' frequency response. Sub frequencies that can't be heard by the ear can still be felt by the body, hence the need to include at least 1 pumpin' sub in your monitoring setup if you really want to track & work with sub frequencies. That's where it starts getting more complex & costly though, as you will definately need accoustic room treatment to do it properly.On 2006-04-22 08:57, Cochise wrote:
How can I correctly level frequencies below 60Hz (supposing that I succeed in achieve them tracking) if I can't hear them?
It follows that a bigger bodied person could has more perception of subfreqs than a little one if they would have the same threeshold
That was part of my train of thought when talking about our bodies' frequency response. Sub frequencies that can't be heard by the ear can still be felt by the body
<font size=-1>[ This Message was edited by: Cochise on 2006-04-22 10:00 ]</font>
Not if they've got lots of fat a la chicken wing & burger eating american rap producers, as the fat would undoubtedly absorb a lot of frequencies before they reached organs, viens & bones 
But how does that figure? Alongside dub producers, they've got some of the best feel for mixing sub frequencies in the industry. Real drum and base producers are probably on par too.
There's a combination thing going on, but it's not been identified or quantified as far as I know.
But how does that figure? Alongside dub producers, they've got some of the best feel for mixing sub frequencies in the industry. Real drum and base producers are probably on par too.
There's a combination thing going on, but it's not been identified or quantified as far as I know.
I used to have a subwoofer in my mixing chain. I quickly ended up keeping it disabled. I found it usable only when checking how my mixdowns sounded in bass heavy environment. However, my room is not acoustically treated in any way. I used a measuring system to adjust the sub start where my main speakers couldn't go. So it was easy to turn on/off the sub.
I'm using Ultracurve for visual feedback of low frequencies that I can't hear. But in my music style, there is no special need for things below 40Hz
I'm using Ultracurve for visual feedback of low frequencies that I can't hear. But in my music style, there is no special need for things below 40Hz
At this point there's a thing I'm wondering about.
Considering the following isophonic curves
showing the behaviour of human hearing at different sound frequencies and pressure levels (the lowest represent the average perception threeshold, the other are for sounds perceived as having equal intensity), I have to deduce that spectrum analyzers used for trace out frequency response curves for studio monitors have to take the isophonic in account, and not use the simple db sound pressure level values.
Considering the following isophonic curves
showing the behaviour of human hearing at different sound frequencies and pressure levels (the lowest represent the average perception threeshold, the other are for sounds perceived as having equal intensity), I have to deduce that spectrum analyzers used for trace out frequency response curves for studio monitors have to take the isophonic in account, and not use the simple db sound pressure level values.
This explain why bi-amplified reference monitor speakers have amplis with huge differences in power for basses and highs
***ADDED***
Not just for that.
Bass freqs need more power than high, even to reach the same sound pressure level (like even in telecomunications a cell phone operating in the GHz band need more less power than a citizen band transceiver operating in the MHz band, to cover the same distance).
<font size=-1>[ This Message was edited by: Cochise on 2006-04-22 20:19 ]</font>
***ADDED***
Not just for that.
Bass freqs need more power than high, even to reach the same sound pressure level (like even in telecomunications a cell phone operating in the GHz band need more less power than a citizen band transceiver operating in the MHz band, to cover the same distance).
<font size=-1>[ This Message was edited by: Cochise on 2006-04-22 20:19 ]</font>
on those curves you can see the ear's response to frequencies below 70Hz is really bad.
These frequencies are perceived by the body (solor plexus region in the first place, if my memory serves correctly), so as already mentioned one needs big monitors for simulating the club PA sensation.
For the playback on 'crappy' 2.1 systems and the like (imho) you'll quickly get the experience to corelate your monitor sound to what it sounds like on that gear.
First of all (most of) that gear isn't exactly quality stuff, and second it's owners don't care anyway (otherwise they'd bought something else)
cheers, Tom
These frequencies are perceived by the body (solor plexus region in the first place, if my memory serves correctly), so as already mentioned one needs big monitors for simulating the club PA sensation.
For the playback on 'crappy' 2.1 systems and the like (imho) you'll quickly get the experience to corelate your monitor sound to what it sounds like on that gear.
First of all (most of) that gear isn't exactly quality stuff, and second it's owners don't care anyway (otherwise they'd bought something else)
cheers, Tom