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Aung Myo Thu, Norght Dagon Ygn, Myanmar

i want to know audio and speaker good system!

Peter, Melbourne, Australia

Dear Mr.Leader,
Thank you so much for taking the time to share your incredible knowledge in this area. I have learned more than I knew existed!
Yours sincerely,
Peter
(and thanks to RP for providing such forums)

Nurredin, Las Vegas, USA

Noone listening to an Ipod is getting any bass. While most of us in the music business have very good stereo systems in our studios and surround systems for our big screens,the average person doesn't.I can hear gut shaking bass in my studio and in my media room,but the kid listening to Lady Gaga on the bus home has no idea what they're missing.I think this is an irrelevant argument for the 21st Century. Unless you're going to a club,the average person will NEVER experience what we do on a daily basis.

Michael Leader, Beverly Hills, USA

Hi Erik... YES YES you are absolutely correct concerning room height. And the lower the ceiling will lower the null that will appear quite close to head level when seated. Another good reason to be in the direct field of the first arrival wave front from the low frequency section. There is a superb article in the old ReP magazine, March 1987...title: Designing a Conical Bass-Horn Control Room by Clifford A. Henrickson then with Electro-Voice as was I. This is a very important work..as the ceiling height was quite low. I would also suggest looking at Google images for Ocean Way studios in LA owned by Allen Sides. The performance of this room is among the worlds absolute...look at the images...and then find the Recording Engineer/Producer ReP article form somewhere. Although it is a 1987 artice, it is even more relivant today than back then. I loved the sound of this astonishing room that Cliff built...abslutely everything sounded sweet..articulate..in place...and talk about KICK...opera, classics and jazz along with pop...everything became an expression of art. I took the pictures for the article.

Cheers...an watch out for your head on the low ceiling. The BIG studios before treatment and the lowered ceilings have an unfinished height in the range of 15 to 18 feet...or more, with some possible 600 to 900 sq ft of floor area, these are large spaces of some 9000 to possibly over 16,200 cu ft.

Michael Leader

Erik, Denver, USA

I think it is fairly clear that this article was geared towards novices who are likely to be working out of a very basic home-based "studio".

While all of the information Mr. Leader has provided is excellent in relation to real world ***large*** studio applications, it isn't directly relevant to the intended audience's goals.

Also, my understanding is that sq.ft. is irrelevant unless you also include volume in cubic ft. Ex: a 12' ceiling vs 7.5' (basement) ceiling yields significantly different requirements, no?

Michael Leader, Beverly Hills, USA

Dear Bill,

Yes you are absolutely right that there are a large number of subs with built in crossovers and summing networks etc. Certainly simplifies the hook up. Again, use of only a single “sub� destroys the ability to experience the movement of bass energy between the channels below 50 Hz or so. Various makers are: Genelec, JBL, M-Audio, Behringer…among others, and I do not endorse any.

I am pleased that you mention the 85dB reference level. Unfortunately the music side of the industry does not use the 85 dB reference at all. Only a few might, who score for picture. But even there, mixers listen to music at higher average level than 85 dB SPL reference, with peaks reaching 105 to 110 dB SPL in “cinema applications�. Ahhhhh, if only life were so easy, as the cinema industry is stuck with a potential peak of only 115 dB SPL PEAK, and most can’t quite make that.

Alternate Content for Digital Cinema is causing challenges for Digital Cinema. While certainly based on a 85 dB SPL reference for film, the low frequency sections in each screen channel, even In JBL’s 4 x 15 inch woofer configuration, model 5674, per screen channel…the system is down -3 dB at 45 Hz..same for the 2 x15 inch (5672) . This will vary depending upon the system being soffit mounted behind the screen or merely sitting on the speaker platform behind the screen with all of its LF energy being bounced around behind the screen. So, the system being tuned to 40 Hz, as in all speakers, the response starts to fall below enclosure tuning…hence no power in the deep deep bass..which at 35 Hz or so is down more than 10 dB.

So cinema has two challenges, 1) how to drive the cinema sound system to sustained levels at least 10 to 12 dB above cinema level..plus headroom, to run music at “concert levels� and 2) the LF extension is required in each screen channel to a corner frequency of at least 28 Hz flat. Oh yes..the system will become very large and costly…but, that’s the fact of life. There is a great paper written by Mr Kinoshita at www.reyaudio.com He talks about his massive outdoor concert systems with extending the bass power response down to 30 Hz Flat, and possibly below. Again the results are astounding. Superb!

So…. For those of you who have seen U2 3D, how did you enjoy it? IMAX levels in theater that I measured never peaked over 100 dB SPL “C� weighing (this includes bass) A scale weighting, the level varied between 90 to 95 dB SPL- A. The bass was horrible.

The Cannes Film Festival was the location in 2007 where U2 3D was presented to the world for the first time. The Lumiere theater seats 1000. Bono played for the audience outside prior to entering for the midnight screening in 3D. The next day, the Washington Post quoted Bono… “not loud enough not good enough, I am serious about volume , good clean loud volume�. Imagine, the most sophisticated audience in the world….Cannes France…. It just so happens, that, this particular sound system had previously been damaged. It was repaired and re calibrated. Limiters were added to protect it…a good idea. But…think about it…..the system had been damaged…was that from an explosive sequence on a loud movie?? We do not know. But, as this system at the Lumiere theater does not have the capabilities to play a movie at loud levels….how in hell will it have sufficient headroom to do rock and roll where at a minimum we require more than 6 to 10 dB of SPL..and the amplifier power to achieve it.

The same thing occurred earlier with Regal Cinemas in the US. Prince Live at Staples Center. Shot live in High Def, it was sent to all D-cinema equipped Regal Cinemas in the US. During the tests, theater managers across the country were asking for more level.. The up link was already getting 0 dB FS…so that was at max. The problem again is the fact that the entire cinema industry was not designed to do rock and roll, or any music really that was not mixed and packaged into a movie. Enterprising cinema managers, (Seattle Washington) turned up the gains on all of their amplifiers. Well, the increase in level was obvious. However, the systems sounded harsh, shrill, thin and lacked the driving punch we all enjoy at a live concert.

So, the 85 dB SPL level works for cinema as an existing standard. The cinemas are still under woofered and seriously underpowered. But a method needs to be developed to satisfy the Alternate Content market. Regal Cinemas certainly did not like to fork out refunds to hundreds of people across the country.

When I hear a music mix in Hollywood scored atTODD-AO, Warner Bros, Sony Pictures or Fox Scoring stage (see the large Genelec’s 1035 on the Genelec Web site) there is a very good spectral balance in the studio. Even sounds good in the mid band. ((Cinemas everywhere are horrible!!!! in the mid band)) Conversely when I hear music tracks from a music studio, on many occasions they are in two channel stereo, without a center..and there is either toooo much bass, or not enough. So, the music guys need to massively improve their systems in order to hear deeper down. This would also assist in the public release of content. Bass is all over the map…and on many occasions off the map. With all of our sophistication today, all the tools at the ready…. Recordings are getting far worse…

Regards,

Michael Leader

www.leadercinema.com

Michael Leader, Beverly Hills, USA

Dear Bruce in Australia…

There are a few options in large scale low frequency sections. While they are a competitor of ours, Meyer Sound Labs in California manufacture the X800 low frequency section for use in studio applications. It is in the $ 6000 USD price range including the amplifiers. It is intended to be used with their X10 two way studio monitor which is a well power balanced 2 way 15 inch system.

In terms of pictures to illustrate my lengthy remarks below, look at the Genelec 1036 which is a complete 3 way large scale system with dual 18 inch devices. But only “look� at this from the perspective of the LF section.

Westlake could manufacture a custom system for you with dual 18’s….

Our D1800 system is made on a custom basis as each and every room is different. The D1800 is slightly larger than the Meyer..our system, such as the versions Leader Acoustic Labs built for Bruce Dunbar, who was David BOWIE’s manager. That system is in Maui Hawaii, as a four way, quad amplified configuration. Obviously there are 2 x D1800’s. They searched the world for two years to find a company who had the engineering expertise to build a very large scale system for large scale studio international class playback. Oh yes..the room is open plan at 2800 sq ft…with an open island of 600 sq ft, which is a full on professional 6.1 area using Dolby DP 564 decoders. The sound system can reach easily 125 dB SPL per channel, and at that level, the bass deep/deep energy remains well balanced. If you would like additional info..please e-mail me: mleader@leadercinema.com A single D1800 in our studio configuration tips the scale at 540 Lbs depending on the custom elements. We have L-C-R systems operating in rooms as small as 680 Sq feet, with the prime seating position at 12 feet back. The power spectrum is flat = 0dB (not down -3dB) at 26 Hz to optionally 60, 70 , 80, 90 Hz. Safe operating below Xmax achieves a challenging 122 dB SPL, filtered pink noise, with a spectrum 25 to 60 Hz. The system will play “bass notes� and patterns. Dunbar has his masters in music, has spent thousands of hours in the world’s major studios, so his reference is on the money for both classical, jazz, pop and everything in between. Oh yes, the system has amazing “cello� balance as well.

We also have a D1500 version, a dual 15 inch high-power system tuned to 26 Hz. Its power spectrum is similar to the D1800, but acoustically about ½ the acoustical power…but with all of the music. Rooms of 300 sq ft to 500/600 s ft are quite fine, and again best when soffit mounted on positioned in a corner.

Kinoshita in Tokyo could make a system for you with the Kinoshita name. TAD large format monitors were desirable, however from what I see, they too are concentrated on medium format and smaller systems.

Other possibilities in smaller subs: Genelec and Andy Munro in the UK is another very smart guy. Most manufacturers have ignored this unique aspect of high end studio applications. They have also ignored ultra-class cinema as well…more on that I am sure later. So the big guys such as JBL do not have in my view a large scale studio solution.

Regards,

Michael Leader

mleader@leadercinema.com

www.leadercinema.com

Bill Bromfield, Stephens City, Va, USA

I'm sure Mr. Leader is correct regarding the optimum system. However, for those with a home studio and a limited budget, who just want to get a good mix without excessive bass, who are recording simple popular music like rock or folk, a single sub can work. In most cases the low end frequencies (bass and kick) will be mixed in the middle anyhow, unlike, for example, an orchestra where you have the basses on the right. There are a number of powered subs available with built in crossovers. You run your mixer's stereo left and right outs to the left and right inputs to the sub. The sub sends the low frequency content to it's own speaker and forwards the rest to it's left and right outs which go to the inputs of your stereo monitor speakers. You then have to balance the sub against the stereo monitors using the controls on the sub. You can start with the sub's volume full up. Listen to music you know is mixed correctly at about 85db measured from the listening position (C weighted)and turn down the sub's volume until it sounds right.

Bruce, Murray Bridge, Australia

Can anyone suggest a model of sub suited to this suggestion?

Michael Leader, Beverly Hills, USA

COPYRIGHT by Leader D-Cinema Systems, Inc 2010 ALL WORLD RIGHTS RESERVED

Author: Emmy Award Winner Michael K. Leader, President
Leader D-Cinema Systems, Inc
Ex VP Studio Systems Group Electro-Voice, Inc

It is most unfortunate that many of today’s mixers and engineers, music producers and performers have never experienced a truly superlative monitoring system in an exceptionally well designed control room. This is part of the problem with much of today’s music recording. I speak from a few decades of experience in the engineering of very large scale monitoring and presentation systems for both multi-channel music to picture, Digital Cinema and Alternate Content, Tracking and music playback. I am none too sure either that today’s monitoring systems are anywhere near the level they need to be either. And the truth of the matter is, with the proliferation of compact monitors Yamaha et al, in the budget price range, attempting to purchase a so-called accurate monitor has the same number of subjective headaches as purchasing an audiophile speaker system at any price range for their homes. I personally find it laughable across both markets the nonsense talked about in terms of accuracy and uncolored sound. If this really is the case, why do all the speakers in a similar size and price range sound sooooo different? Think……

The ridiculous concept of running a single “sub-woofer� to extend the limited acoustical power performance from baby sized monitors is preposterous. Sure it’s done. But do you really understand what you are doing?

The greatest fallacy foisted upon us from the movie industry, is that low frequencies are directionless, as the wavelengths are so long that we do not lock on to a direction. This is only somewhat true for sustained energy….traffic rumble, low frequency filtered pink noise, single frequency sine wave..pick a frequency say 30 Hz…even I doubt I would quite know from where the source was located. Should you be fortunate enough to be in a real studio, have someone wind up and do some hard kicks on a drum set. Deliberately place the kick on the left or right channel and low pass the kick say at 70 Hz. Then route the kick to a single “sub-woofer�…you will immediately realize that the impact of the beater on the skin creates a pulse which has direction. Same for electric bass, string bass and symphony orchestras and your deep synth runs.

What does one require in a full range monitor system:

SOFFIT MOUNTED Systems are a must. If the system is not soffit mounted, the random energy rolling around behind the box, off to the sides, and top to bottom becomes delayed energy arriving behind the first wave front has passed your ears. Boomy bass lacking definition and source location are all major issues with non mounted monitor systems. In addition, SOFFIT mounting smoothes out the response, provides you with free 5 to 6 db of low frequency gain, and a degree of bass smoothness that can not be matched through equalization..no matter who made it or how many digital bits and sampling it might have. If you have monitor speakers with the vent in the rear of the enclosure…you are out of luck.

At a minimum, the low frequency section needs to reach down to 25 Hz..flat in power bandwidth. This is not quite the same as frequency response. Well it is frequency response…but with attitude…it means that this box as specified “should� get down to 25 Hz as listed on the data sheet. The attitude is, can you do this at its long term average or continuous power handling….I’ll bet you can’t, and this is why you cant hear the real depth and power of the bass. Be prepared to spend real money. A 10 inch 200 watt 2 cu ft box is a toy, as you will see later.

Power Compression ideally should be zero. All woofers, even the 18 inch, well designed woofers by EV and JBL in the 1000 watt 4 inch voice coil range will suffer from power compression if you pound them with more than its long term average power rating. Power Compression is due to heating of the voice coil. As the heat builds up, so does the resistance of the voice coil. The higher the resistance, the less power the woofer draws. You turn it up…and it begins to sound lousy..and after a few minutes yu are aware of a very strange expensive smell, as a unique shade of blue smoke emerges from the box. So, if your have a baby “sub-woofer� its overall power handling with be quite limited. A cone woofer’s reference efficiency will not be much greater than the 3% range. So, with lets say 100 watts power handling for a 10 or 12 inch woofer, @ 3% efficiency (on the high side) the output in Acoustical Watts will be 3 acoustic watts. A popular 8 inch 2 way, American made good monitor typically found in broadcast studios has a ½ space reference efficiency of 00.6% with long term power handling of 30 Watts the system will play at 107 dB SPL above 80 Hz. Its output in Acoustic Watts is 00.18 watts. More on this follows, but power compression is a significant issue.

Stereo 2 channel low frequency energy. This is forgotten, that there is significant “movement� in music below 50 Hz region. In live music, in this case lets take classical, the row of double basses sawing away creates energy that both reaches the ears of the listeners directly along with highly desirable reflected and delayed sound emerging from the side and rear walls of the stage area. This energy moves across the stage, and given the recording technique, this very low frequency content is there. It simulates sustained low frequency energy. But, if you have any doubt, mono the two channels during a session and experience the room collapse. Have you heard the term about control rooms “breathing�? There you have it. It IS a part of the performance. It is a part of the art form of music. And it is a critical element missing in over hyped consumer speakers at all price range…and even more so in studio systems as we will see.

It is fascinating to listen to sound effects libraries, recorded either in two channel stereo or Ambisonic. Out door atmosphere is dramatic in two channel…if! Your systems can get down..way down to below 30 Hz. Even a gentle wind will create movement. Listen to the deep growl prior to a thunder clap using two high performance systems that can get down. The switch to mono…either sum both channels…or mute one. The difference is like listening to a 1970’s car radio.

Matching your 5 inch, 8inch 10 inch whatever number of inches you have (!) compact monitor to a sub woofer is a hugely challenging experience, as there is a massive difference in the output capabilities…er..thats right measured in Acoustic Watts. So, your 5 inch..ok 8 inch box, for the most part has no energy in the region where you need to augment its output. So, even with our simple example above with the 3% efficient cone woofer, the disproportionate acoustical power is the reason that there is such controversy in matching a woofer to a compact monitor. No Amount of time delay or parametric eq will fix the miss-match. In addition is is highly unlikely your acoustical space is good, and the monitor system is not Soffit Mounted. The best you can do, is to make sure the system is at least in phase. If you like and have the experience, you can sweep very slowly with a sine wave generator, or use pink noise with a good RTA. Watch for holes in the transition as you are crossing over between the two. If augmenting and the compact monitor is running full range, you run the risk of bottoming the woofer in the compact monitor. Then find a good solo recording of a cello..hopefully you will know what a live cello sounds like. Cellos are difficult to maintain the power balance in studio systems…the great systems can do it seamlessly….try it…. You might be surprised. You can also use a keyboard….run some scales…and also run scales in different keys…you will be most surprised with the shift in density.

You will experience a benefit with the small compact systems even with a baby sized woofer extension in each channel. If you do apply an active crossover between the compact full range monitor, set the crossover about ½ octave above the specified 3 dB down point. This will insure that the full range system will not be stressed with low frequencies below the tuning frequency of the full range system. Once you have everything balanced, the improvement in clarity should be evident in the mid band. This is due to removing low frequency energy and at high levels, the passive crossover network in many passive systems can have the coils saturated if the coils are not air core type. In any event, the removal of low frequency content from the woofer in the full range monitor, will improve the sound quality.

I am amazed how, that so many project studio owners have the need to run out and purchase Neumann, AKG, Sanken, Schoeps and other exotic microphones costing thousands of dollars. You have a big or small session. Now lets see..a few expensive microphones….what $ 10,000, maybe a few instruments.. a Strad or two, maybe and Amati and Guarneri…so maybe $ 30 million of instruments in the trio. Or your session has a signed original Les Paul or other million dollar treasure…along with the group…say a modest $ 2 million of instruments. The mics are in place….the record button is pressed… ok you hard drive has been recording everything as your terabyte of space only costs pennies in comparison to 10 inch reels of tape. The down beat…..the music…the passion..the artistry of music..the professionalism…..and you are monitoring it on speakers that cost less than your array of microphones.

Low frequency distortion. You would not like to see the distortion specs for any ones low frequency system. 15 inch, 18 inch 24 inch, the really really good stuff, no you still do not want to see the distortion specs. But do not worry. The human hearing system being much less sensitive at low frequencies (Fletcher Munson) masks the annoyance of distortion curves that do not look pretty. Keeping the low frequency section large, will provide you with greater sensitivity. If you are fortunate to have a dual 15 inch or dual 18 inch system tuned to 26 Hz or so, for each channel and soffit mounted, you will truly experience another dimension, and one that all of the exotic makes of snake-oil price range speakers have never experienced. Two woofers in an enclosure couple and sound superior to a single driver. The next challenge is in finding top flight amplifiers to provide the control with high damping factor. I use American made Crown amplifiers in our systems, with DF > 3000:1 I also provide amplifiers with more than 6dB of headroom over the woofers Long term power handling. So, a 800 watt LTA woofer will have 3200 watts peak capability per cone, as I apply a single amplifier channel per cone.

X Max and X Max Limit. This is a very long story. X Max is the specification that produces 3% distortion. It is safe to operate a woofer to X max. depending on the voice coil and heat sinking, I would not recommend operating continuously at X max. We design our systems for the max level we require at 10 dB below X max. Remember, that for every increase of 3 dB you are doubling the amplifier power. This becomes a very costly and demanding design feature if you want to have your system to operate at military levels of mission critical performance. Ok..so you want to lean on it and play BlackHawk Down at realistic in chopper levels…no problemo. The music will sound effortless and musical too. X Max Lim..is the danger zone. Lim is the limit at which expensive mechanical damage will occur…followed by that annoying expensive smell.

How will you know how great your low frequency performance is? A few ways. Find a classical recording made in a church or auditorium. A budget recording will possibly do. If you can feel or hear the air conditioning system, at a very low level, your system certainly is reaching down there. Possibly the same recording, if done in a church, will exhibit low level rumble from traffic outside and or a combination of traffic and HVAC…this is hi-fidelity! Obviously play music…the extension should reach deep easily to 35 Hz..flat…without any silly humps between 60Hz to 120 Hz, if anything slightly notch 70Hz to 110Hz due to room combining.

Last test, and I am serious. The motion picture Master and Commander. The first battle sequence between the British and French ships. If you are unable to hear a difference in pitch and impact between the French and British cannons, you do not have an accurate woofer system at all. The Walt Disney Post Production sound department first experienced this phenomenon on one of our Leader Hollywood Format™ 4 way very large format systems in the Aidikoff Screening Room in Beverly Hills California. There is a difference…what a test…and try playing it at 120 dB SPL…well we can…bring two check books. But it is possible.

Finally, you might be wondering who can hear down this low and deep…. Prince’s studio Paisley Park Minneapolis, the control room is equipped with an astonishing system (not ours) by Westlake Audio SM-1 5 way..each enclosure is equipped with dual 18 inch woofers….Output in acoustic watts we calculate at 58 Acoustic Watts per enclosure at low frequencies.. Kinoshita Monitors were specified by Tom Hidley for Bop Studios South Africa. System reaches down to 9 Hz…for this you will require three check books www.reyaudio.com Our clients have it as well….we have a passion, so visit us at www.leadercinema.com We manufacture world class large scale systems for both music industry and motion picture industry professionals.

Good luck in your search for “sub-woofers� for your compact monitors….but first visit the drug store for a bottle of aspirins.

Regards,

Musically Yours,

Michael Leader,


Copyright 2010 by Leader Cinema Systems, Inc
ALL WORLD RIGHTS RESEVED

Shelter Studios, Schaffhausen, Switzerland

This article addresses some of the basic
issues but has neglegted to raise an important and fundamental question namely, what kind of studio you intend to build e.g. Music Production, Mastering, Post Production, Broadcast, Post Production for motion picture or, a Critical listening environment. The type of studio will determine what the bass reproduction requirements will be and what the costs of providing all that can run to. Since that discussion would be too extensive for this forum here are a few tips: For the home or project studio a sub-bass driver of not less than 10" is a sensible starting point and there are a few useful and affordable active products available. A down-firing unit is helpful where space is limited and reduces the side effects of the direct wavefront. Most low frequency active monitors have a built-in low pass filter so, don't apply external LP filtering or the rolloff will be too steep. Setting the right SPL levels is the most critical and will require the use of a SPL meter and a Pink noise source. In a domestic setting the maximum SPL at the listening position from a complete set of calibrated speakers should not exceed 79dBA.

Phelps, Booo Lol, Us And A

supposedly krk has created a subwoofer that automatically crosses over the monitors with the sub that is controlled by a footswitch. any take on that?

Neiko, Melbourne, Australia

Good article, so what is the minimum
size speaker which "will" provide good sub bass?