Take the time to skim over this. I hope it will help some people to avoid some traps!


Some advice on choosing speakers for your studio

1/ What are good monitors ?

A good set of speakers should give you an ACCURATE picture of your sound while you record and mix.. What is meant by accurate is a reproduction of the signals that truthfully reflects the signals you have chosen to record and playback. To do this the speakers should have an excellent phase relationship and a flat frequency response, both of which are very difficult to do.

And then there is always as your listening level increases, this is the problem of the room that you are monitoring in.

It is always important to keep in mind the eventual " audience " who will be listening to music You should mix your music on a system that corresponds to the one that the majority of people will be listening to it on. For example if your " product " will be heard at a night-club or disco you will need at some point to listen to large monitors with large woofers to get a complete picture of how the bass is reproduced. If your product will be broadcast on television you need to monitor in mono and on small speakers, ideally from a television itself. If you believe that your work will be heard on both then you should do trial listening over several different sized systems.

As the majority of persons will be listening to your music on a hi-fi system in their home, your first choice in monitors should be of a size that relates to this. And the speakers should still give you a " flat response " or unflattering response curve to judge your recordings.
But …..there are some other things to be aware of……

2/ " Closed cabinet " vs. " Bass –reflex "

The recent trend in studio monitors is towards " Active monitoring ". Speaker manufacturers are now matching speaker designs to the amplifers that power them. This is great, as the same speakers sound different when powered by different amplifiers of different power ratings. Now you can be sure that your active monitors will sound approximately the same where ever you listen. Or at least you have removed one element from them sounding different, the room is still going to change the sound.

That is the positive aspect of " active monitors " the negative is you carry around heavy speakers, and to help you out the manufacturers have very kindly given you a " bass-flex " design. Great, you think. But…..

Put your hand up to those ports/holes in the cabinet and you get nice little puffs of air (and sound) everytime there is a bass signal. Are they in phase with the signals coming from the woofer? The constructor will swear they are…..but are they? They are not.

Do a comparison between a " closed-cabinet (non-ported)" design and a " bass reflex " and you will hear the bass smear and spread of the sounds coming from the bass-flex cabinet. And while most speaker systems are of a similar design, especially hi-fi that love to give an exaggerated bass, it won’t tell you what your bass frequencies really are.

Listen to a bass-reflex monitor system, can you pinpoint the bass? Or is it all wide and floppy?
Now do the same on closed monitor; the bass is tighter and more focused as there are only 2 sources, the woofers, no holes front or back. The transients will be better defined as they are correctly aligned giving you the accurate “in focus”picture.

Some manufacturers use “tranmission-line” design to partially overcome this. They build in a labyrinth for the sound to run through and thesound comes out 180 degrees out of phase. Your fundamental freqencies are 1 cycle behind,,,, but the attacks are better, because theyare ligned up again.

You can mix and record on Bass-Reflex lots of people do. But you run a much higher risk of NOT having the bass content you thought you did. And when you playback on a friend’s hi-fi the sound can be without all the lovely bass you were sure was there! !

3/ Proximity vs. " a good room "

If you want to spend a lot of money fast, buy huge speakers, run them loud, and do an acoustic treatment of your listening room, You might impress your girl-friend.

Or…..
Save money by buying small near-field monitors, run them at a low or comfortable level and don’t treat your room. You will impress your wife and the master engineer!

If you are a Pro studio this won’t be possible, some deaf musician will always ask you to turn it up, and most client still confuse LOUD with better, usually it is the opposite.

As you turn up your monitors, the room acoustics come into play. And your room is a swimming pool of full of little waves reinforcing or cancelling each other out. Each space has a resonance and it will be apparent in your mixes, as it will be the frequency that will be missing in your mix. If you mix with the vast majority of the sound coming directly to your ears from near-fields, you stand a better chance of not screwing it up.

Once again if you could only SEE the sound, the problems would very apparent.

4/ Woofer mass and dynamics

I recently heard some very impressive Altec-Lansing " Voice of the Theater " speakers with 30cm woofers made of paper with very low mass and we got 109db with 2 watts of power! The resulting dynamics were incredible. The drums and bass were so present.

Only drawback, they are very fragile.

A boomer pushs air forward, brakes, stops, then moves backward, brakes, stops. ETC… The more mass or weight the Boomer has, the more inertia it has, the more difficulty it has to stop and reverse direction. The lighter the truck, the faster it will brake, try it with a load of bricks in a van.

Obviously the less weight or mass a boomer has, the easier it is to respond to the task of reproducing the sound wave asked of it.

The test for judging this is to listen at LOW level for the dynamics of the music. If the speaker has a low mass the impression of having dynamics will be there, if you have to turn up the volume to get a " punchy " sound the boomer is a fat, lazy guy who will never move like he should and will eat up all your amp’s power to get dancing.

Here again “closed speakers” have an advantage over “bass-reflex”. The expanding and compressing of the trapped air behind the woofer helps to overcome the inertia of getting the woofer moving and then getting it to brake, instead of overshooting. The “bass-reflex” models cannot brake as fast because they are sucking or pushing air out the port. They are free to overshoot it is only the amp calling it back magnetically that is operating.

The “closed speakers” design has the amp and the air working for it

5/ Sub woofers

Personally I mistrust them and would only mix with them if I were required to do a 5.1 surround mix where the playback system would include a sub-woofer.

First there is the problem of the phase relationship of the third source of the bass frequencies, and then there is the fact that all the bass frequencies will be accentuated. The risk again is that you get an artificial boost in the bass, and you do a bass-light mix. Where did all my lovely bass go? This is what you will be asking yourself when you listen to a friend’s system WITHOUT a sub-woofer.

And then there is that "swimming pool" of a room to think about.

Best avoided.

6/Monitoring Levels

Imagine you are 40 years old sitting at a bar, and 6 feet away is a beautiful woman discussing not too discreetly with a friend how attractive you are, but you can’t hear her.

Monitor loud, for long periods and often enough and it will happen to you.

Keep going on abusing those subtle receptors on either side of your head and your mixes will terrify dogs, young children and most women because of the over-endowed high frequencies that you can barely hear.

Keep your monitoring levels at a reasonable and you will get compliments on how well you have aged.

Mr.B

nice info... this may serve better as an article for the site

you should post here

In reply to the original poster:

It is a correct statement that monitors should have accurate frequency responce, but is phase linearity really important?

Older studies (from the 30-s to the 60-s) showed that the human ear cannot detect phase irregularities.
New studies has been made on this subject though, and it seems that a trained ear, if it knows what to look for, can detect irregulrtities in phase, in allpass systems, in the area 200-2000 Hz. The signs are very subtile and is detected primarily in the musical flow. It does not seem to affect the resolutions of detail or perspective as is commonly believed.

Also the suggestion that bass reflex speakers are less phase linear does not have to be true. it is possible to design a passive crossover what corrects the phase in this type of construction.
I know of some bass reflex speakers that are very phase homogenous. Also, I know of closed cabinet constructions that are not.
The frequency responce in the low register can be made to be VERY accurate in a bass reflex design!

Regarding subwoofers:
Again, Mr. BBBB is speculating. it is possible to make subwoofers in phase with a full range system. This is what you do in an allpass system. This is a question of crossover design.
Allpass systems has not been proved to produce any audible artefacts.

The speculations of Mr. BBBB are well intended for sure, but they are not all true.

It is a correct statement that monitors should have accurate frequency responce, but is phase linearity really important?

YES, IT IS IMPORTANT.

One year ago I conducted a shoot-out of various D to A converters as objectively as possible. One of the criteria for evaluation was the stereo width which was much easier to judge with a "closed" speaker design.

The fact is that many of us have encountered situations where persons are listening quite comfortably to a stereo system which is set-up out of phase. Or in my opinion, even worse, come across a professional studio where the monitors are out of phase.

The recognition of proper phase relationships is simply a matter of it being pointed out. It exists, and it is part of everyones evaluation of where the sounds are located in the space around us.

You only need to start recording with a matched pair of microphones in stereo to realize what phase is and how important it is. But we all intuitively recognize phase and its clues to the environment we are in.

In fact the best examples for judging the quality of converters are simple stereo recordings. They are also the best material for judging the quality of your monitoring as speakers that can deliver an accurate phase response do give you a larger stereo field, and more depth ( a lost art since the multitrack, multi-mono recording era began).

We all are more comfortable and less fatigued by speakers that are more accurate phase-wise. Even the local grocer can "feel" a better phase response without being "trained". It is more that it has to be "explained".

The very first time you heard something out of phase, you knew something was "WRONG" but did you know what was?

PHASE is VERY important!

And a passive crossover does NOT correct the fact that a hole in a cabinet has sound coming out of it. The length of the air passage or the size of the enclosure matters more. Then there is the problem of resonance, it is a messy design, the bass-reflex.

Subwoofers add a ADDITIONAL source of sound and therefore another source of disturbed phase. If sound was something you could see, you could not miss the fact that it was "out of focus" with this additional source.

Put another way, if you were miking a bass drum, you would would be very careful if you took the decision to place a second mike somewhere, right?

WHY?

I don't speculate, I listen very carefully to what I record, to what I hear, and to what people that I respect say to me.

And the "truth" is out there, it is not very well represented by what is supposed to be good "studio monitor" speaker design today.

What we are talking about here is phase linearity in loudspeakerdesign. Generally these small deviations in phase are very diffiult, or impossible, to detect.
Of course if a loudspeaker is phase correct, this is good, because the anomalies, as I said, can be detected, if they are in 200Hz-2000Hz. But this is not by far the most important factor of a correct sounding studio monitor. I suggest you measure up a Genelec 1031A and see how they perform.
You also suggested that a bass reflex speaker cannot be phase linear, this is wrong.

Regarding subwoofers, they can be made to play in phase, or more correctly, you can make a system that has a complete phase rotation around the crossover frequency. So that all parts play in phase.
This does not apply on a 5.1 system where the subwoofer plays it's own information (as I understand it). Also one subwoofer does no good. At least two and preferably four subs is easier to place for optimal performance.

Could you please suggest how a bass-flex design CAN be phase linear, is more to the point!

Again, if I record stereo with TWO mikes, I have a reasonable chance of a recording with a good phase response.

If I record with FOUR mikes, if I line up my attacks with my favorite hard disk recorder, I might be OK.

You can't do that with a woofer and a port, there is the physical distance between them and no electronic delay to compensate for it.

PMC and ATC try to do it with "transmission line" designs, that mean the signal is 180 degrees behind, so the attacks are lined up.

The Genelecs 1031s were one of the worst in the "respect of phase" department for the converter test we did. In A/B tests we could hear the stereo width being reduced. I suggest you try testing it yourself, we already did.

Correct phase with a sub-woofer with a cross-over frequency??
No, by using delays correctly, Then it is believable, it is a distance thing. I have been in studios where we set-up the response in frequencies AND phase. And the phase was corrected by delaying the mids and tweeters with time delays. And the monitors sounded better to everyone once the phase had been tightened, even the janitor.

Why don't speaker manufacturer publish their phase reponse on their very informative web-sites?

They don't want to scare us.

Here is the deal.

Forget the 200-2000 hz and anomalies stuff.
Take 2 different pairs of speakers from different manufacturers and play the same stereo recording.
One will sound wider, and have a tighter more compact bass in the center than the other.
What are we hearing, according to you?
It's phase response, right?
And my mom can hear it. So can yours, I hope.

And it is NOT impossible to detect, IT IS RELATIVE to the differences between the two monitors.
I am talking about the CORRECT REPRODUCTION of the phase relationships that were recorded. And this you can hear some speakers doing a much better job at this little task. And the speakers you mentioned are NOT at the top of this list.

Mr. BBBB you totally hit the nail on the head i totally agree with what your saying.....right on bro

Thanks for your support.
The "shoot-out" of the converters is one of the most interesting things I ever done, it made me re-think about monitoring and got me back into recording in stereo.

Two (great) mikes =depth

Try it on a percussion track, only 2 mikes, way back to take a "stereo-photo" of the room, inject it into a dry mix and the brain puts everything into that space.....fun