Tube Amp Forum: The Ultimate Tone

Hi Guys

Anyone who has read my books knows that my preference for music playback is proper stereo. There are several aspects involved regarding how to achieve the same experience in the listening room as existed on stage during a performance. That stage might also have been a recording studio, where the recording process can alter the performance quite radically depending on how each instrument sound is captured.

The simplest approach to recording with an eye (ear?) to playing back in stereo, is to use a two-microphone  setup to capture the room mix. This mimics how a listener would experience the performance directly, and hopefully this transfers correctly to the listening room experience. There are thousands of recordings made this way from the earliest days of electronics up to the digital age. Some are great, some are poor, and most are good.

In our stereo recording approach, we can use two microphones on their own stands separated however the recording engineer determines, or two mics can be "crossed" at close proximity to each other, or a binaural mic-head can be used.

The separate microphones method is the easiest to implement as it requires no special equipment and actually the minimum of skill to achieve a pretty good result. The microphones should be in positions where listeners would be, far enough away that each microphone picks up all instruments. Their left-right positioning should be modest but distinctly not coincident; rather, tending to extreme separation. This provides a natural blending of the sounds with room ambience for a normal feel. If the microphones are widely spaced, the distinction of instrument placement across the stage may be enhanced, with caveats: Each instrument must have its own single speaker cabinet or "zone" where its sound is dominant; the PA sound ideally carries only vocals or has a proper mix corresponding to the stage positions of the instruments; or the PA sound is minimised as much as possible in the stereo microphone placement.

There are a lot of details in the above descriptions to be expended upon as we go along.

The binaural head-mic is designed to mimic the placement of Human ears within our head, and thus, the mount is shaped like a Human head, with ear canals that have microphones at the place where our ear drum would be. The exterior contouring is either highly simplified or shaped to represent an average shape of a Human ear. Ears are unique and no two people hear exactly the same thing. besides, our brains make an interpretation of the information coming from our ears as to what it is we are hearing.

The stereo signals captured by the microphones only need two tracks on tape or whatever form the recording system takes. Playing it back on a distortionless home listening system is the ideal case, especially if that system is properly positioned in a"Human conversation rated" room.

Hi, thanks for starting a thread on this! I really do find it interesting. I've wondered about just recording the room, like you mentioned. Since live mixes at times sound great as a listener in the room, I find it curious that common practice (in popular music genres) seems to be individually miking each instrument and then fiddling with stuff in post. I suppose it gives the engineer more control, requires less musicianship of the players since they can cut their parts in and out, retrying endlessly, you can apply effects to the various tracks, etc. Still, there is something alluring to me about recording... raw, for lack of a better term. In part because it seems like you'd have better band dynamics.

(08-29-2023, 04:45 PM)K O'Connor Wrote: [ -> ]If the microphones are widely spaced, the distinction of instrument placement across the stage may be enhanced, with caveats: Each instrument must have its own single speaker cabinet or "zone" where its sound is dominant; the PA sound ideally carries only vocals or has a proper mix corresponding to the stage positions of the instruments; or the PA sound is minimised as much as possible in the stereo microphone placement.

Hmm, so if I'm running a(n) (ultimate) symmetric setup, then I don't care much about extra wide spacing, since part of the symmetric idea is to have uniform sound across the stage for all the amplified instruments. Is that correct?

Thanks for all the great info you've already provided. I hope the music club I'm part of will allow me to set up a few mics to try this out during our performances this semester, really curious how it will turn out. You've described it of course, but I want to experience it myself.

Hi Guys

With a pair of microphones, we can make an approximation of the binaural head-mic by placing the individual mikes in a V-shape. The bottom of the V can be open or literal. Having the microphones angled out allows a slight overlap but very strong left and right separation. Ideally this V would be placed on the center-line of the stage and reasonably distant so no single instrument dominates the mix.

If the V is made smaller so that the microphone bodies actually cross, then there is an emphasis of room ambience, but still a reasonable left-right sonic capture.

Presumably, the stage mix set by the individual performers is balanced in a way that the musicians feel represents the band properly. How common this is in practice is anyone's guess. Factors including inherent loudness of the instrument, the player's skill, the suppression of individual ego for the betterment of the band, and the positioning of speakers for individual instruments all contribute to whether the band mix is good or bad.

As discussed in the TUT-series, most inexperienced players think that being on stage gives them free reign to play as loud as they like. They go from bedroom-level practicing, to jamming with others, to jamming with drums included, to a stage. At each step, loudness increases, particularly when drums are present. Drums are generally used as the reason and excuse for playing louder and drummers are generally the scapegoat.

It is true that inexperienced drummers lack dynamic control, but a wider problem is actually the trend in available drum heads. Traditional drum heads have a "snap" when hit hard, but they can also be played quite dynamically down to very quiet levels. Hydraulic heads are fluid-filled and have more of a "thump" with very little attack. They are designed to withstand very hard hits and behave very much as if there is a threshold below which there is little or no sound at all. The drummer's statement that he has to play this loud is not entirely false.

On stage, it is hoped that every musician can hear every other instrument clearly, and that each participant allows space for the high-lighted voice. In classical formats, a conductors guides the musicians as to how to express their part, and makes space for soloists throughout the performance. Early pop and rock bands did the same although usually be mutual agreement, allowing focus on the vocal, or on a solo instrument. As the music became denser in the midrange frequencies, either with more players in the band, or with more complex or distorted instrument textures, the need for "making room" became more important yet generally became less frequently employed.

Most modern players tend to play as hard on their instrument as possible, with no change of loudness other than stops and starts. This reflects a lack of musicianship and a lack of a band mentality. Certain music types are more prone to this behaviour than others, but it is safe to say that all music styles suffer this egotistic indifference. With amplified instruments particularly, there is absolutely no excuse for such playing as the dynamic range of the instrument is greatly enhanced. An example of this is Ritchie Blackmore's performance of "Catch the Rainbow" on the Rainbow On Stage album. He begins playing so softly that the audience must be very quiet, with a build up to a full-band crescendo that taxes the recording and playback media capabilities.

Most pop music became compressed to maximise effective loudness for radio play. With loudness at maximum, the resulting radio signal was also maximised which gave better range of dispersion. Of course, that only mattered for AM, not FM. With the highly compressed mixes, as vocals come and go the texture of a song changed but its loudness did not. Individual instruments were mixed in as loudly as possible. You hear this particularly when a single instrument begins the song: it is loud and clear until the next instrument or the band joins in, at which point the first instrument is squashed in the mix. Vocals are simply mixed over the band instead of the band making space for them. Unfortunately, most live mixes are handled in exactly the same manner.

There are a lot of factors working against live sound being as good as it can be. The major factor is sheer loudness.

Human hearing evolved to deal with the sounds of nature. Human conversation is about 40dB above the threshold of hearing, and 80dB is quite deafening. Everything above 80dB is strictly abusive and harmful to our hearing health. We call the 80dB limit the top of the Human Scale of loudness. The presence of ANY and ALL sound invokes our aural compression, which is our physiologic protection system. As sounds get louder, we hear them less accurately and instead have an illusory impression of the sound. The reality is that if we want to accurately hear our instrument tone, we have to play it quietly. The same applies to hearing the band, or when we play back recorded music.

In the end, we hope that the performance we are trying to record is worth recording

Hi Guys

Obviously, if a serious recording is to be attempted, we should use proper equipment, so NOT your smart-phone

The type of microphone used should be one that has a wide and flat frequency response and low-noise. Generally, these will be condenser mikes which can be either battery-powered or phantom (remote) powered. Dynamic mikes using neodymium magnets should be avoided as the lightness of the unit is not worth the trade-off for extra treble distortion.

The recording path should be low-noise and low-THD. Many old-school sound engineers will argue that analogue cannot be beat, and certainly if one could use large-format tape the results would be very good. The very best digital equipment can rival that performance, but the engineer must be able to deal with the domain's own limitations.

Hi Guys

Just to address a question from post-2 with respect to the use of Symmetric Stage setups and recording:

The symmetric Stage cabinet layout is used to optimise the on-stage sound for the players AND to optimise the off-stage sound for the audience. As TUTs 1&2 and SPKR detail, the cabinet positions for each instrument effect what a player hears AND what the audience hears.

For example, suppose there is drum center-stage, bass to the left and guitar to the right. The bass player is standing next to his cabinet and hears his own instrument very loudly, hears the drums pretty well, and may hear the guitar a bit lower in his own acoustic mix of the band for where he is positioned. The drummer hears the bass and guitar both with treble attenuation, as he is likely to the side of both cabinets. The guitar player hears his own sound loud and clear, the drums pretty well and the bass slightly lower in his acoustic mix. The Symmetric Stage evens out the acoustic mix across the stage so everyone hears everyone else pretty well.

For the audience, a person sitting in front of the guitar cabinet will be blasted bu guitar and may not hear the rest of the band too well. Similarly, someone sitting in front of the bass cabinet will be blasted by bass and may not hear the rest of the band too well. Someone sitting center-stage may hear everything reasonably well, possibly with an emphasis on the drums. The Symmetric Stage evens out the mix for those audience members sitting off-center, which is pretty much everyone in the room.

As far as recording a performance where the Symmetric Stage is employed, there is much more freedom of where to place the two microphones as the mix is almost monophonic. Still, positioning the mikes on the center-line will capture any left-right orientation of drum elements and contribute to some stereo feeling.

I always prefer live concert recordings as historically these show off the players and the band at their best - interacting with an audience with the cycle of energy feedback between them. The first live album I encountered that had overdubs was one from Def Leopard, who wrote "There are a few overdubs, but it's only rock'n'roll". Well, if it is "only" rock'n'roll, leave it how you played it live !! I found it to be an insult to the people buying the album (which I had not, it was my neighbour's).

Any performances or jams I recorded were always done as a room mix. This always provides a very natural and listenable feel.

Generally, recording the band playing the song together will be a first step when recording an album, and represents the "bed tracks". These began as room mixes and as more recording tracks became economical AND as recording engineers began thinking of themselves as "the fifth member of the band", bed tracks may be single-instrument tracks but recorded all at one time. Laying down further tracks to "improve upon" the original tracks is either beneficial or not. In general, it tends to ruin the overall performance inasmuch as it is extremely difficult to go back to the first performance once you have added every cool enhancement you can dream up.

An example I cite in TUTs regarding this was with respect to the Rush "Slings and Arrows" album. A true fan was chosen as the engineer / producer, who claimed he wanted to get the band back to its essence of being guitar-based. With that, every track had multiple electric guitar tracks as well as acoustic, and drums and bass. Further to this, no song was consistent throughout, meaning it may start off as a blues song, say, but then morph once or twice into quite different styles, which tended to blur all the songs together, leaving none of them distinct nor memorable.

Other albums from various bands may be optimised for radio-play and then sound terrible through a home stereo. A case in point was Ozzy's first album with Zakk Wylde. The selected track for the single sounded pretty nice through a typical radio speaker, but the mid-sucking over-emphsised bass tones were very annoying through a proper stereo playback system.

Hi Guys

As an addendum to post-3:

As far as guitar playing technique goes, many players never develop good pick attack control. Yes, they can hit the right strings but they lack dynamic control. They tend to use distorted or compressed tones to even out their own playing, which makes it difficult for them to play quieter and make a space for a soloist even if they wanted to. This used to be music-style oriented, where metal players would just bash on their strings all the time, but you find this dynamic control loss in all music styles.

On stage, adrenaline can hop up the playing tempo and the loudness.

The initial loudness will invoke your aural compression which will roll off treble, making you want to play louder to compensate, invoking further tightening of your ear drum, rolling off more treble, and so on. Combined with the excitement of performing, an untenable cycle is formed where it becomes impossible to experience a good sound throughout the performance. Lack of a band ethos will make all of this worse.

If the player lacks dynamic control of his instrument, then he does not make space for the vocalist or any other spotlighted voice in the band. Something many players do not realise is that space between notes actually makes each note more powerful. So, if the intent is to "crush" the listener, it will be more completely attained giving quiet gaps between "pummelings". Those spaces allow the listener to process the note just played and appreciate how well you played it. Every guitar player has his own style, and whether you consciously do it or not, there will be inflection in the notes and chords you play that distinguish you from other players. This distinction is enhanced with dynamic control.

Playing too loud does not make you sound better, it distinctly makes you sound worse. The listener's aural compression will be strongly invoked and they will not be able to tell if you are the best guitar player in the world or the worst. They may not be able to tell if it is a guitar you are playing without seeing the instrument in your hands.

Really nice posts. Thank you for the enlightening read!

I particularly like the parts about pick dynamics and controlling loudness in a band/performance setting. As an amp builder one my main goals is to make amps that are touch sensitive, respond to pick dynamics and all of that should be possible at normal non-damaging volumes.

It's a challenge to educate players----I know many players who play far too loud and many who have not developed pick dynamics. I'm not sure that it's entirely the fault of the player though. So many modern low-priced amps lack the ability to reproduce dynamic picking. When I built my first good amp, I found I had to re-teach myself how to play. The cheap solid-state amps and tube amps I'd owned only really seemed to work well when very distorted. I bashed away at the strings without developing feel until I got a better amp.

I would comment on the recording aspect of the post that most studio recordings from the mid 60's onward were done with mics for each instrument. There of course are tons of great recordings done with a few mics before then and lots of live recordings and bootlegs (Ray Charles at Newport for example) that are done with mics in the venue.

The approach that is taken with recording seems to make a huge difference. It may be just personal preference, but it seems to me the more of the recording that is done live the better. An over produced and layered record may be interesting from a technical standpoint but doesn't connect with me as much. While I'm not a big Beatles fan there are some very interesting videos and fairly comprehensive information on how they recorded---it was so simple in comparison to most recordings today. It's hard to argue with the results.

Any how thanks taking the time to post all of that. Great stuff!

Man, I need to check this forum more often. Thanks for the great information, and the answered question! I managed to find a full album recorded using stereo techniques in the room, and I really like the production qualities it has. No panning, compression, or limiting applied in post either apparently. https://www.youtube.com/playlist?list=OL...em-igBJymA

I'm pushing to get some local musicians and a recording studio to try this out sometime. So far I haven't found a heavier album recorded this way. If anyone knows one, I'm all ears.

Somehow I forgot all the good info that is in this thread... Thanks again for writing all that Kevin. Anyhow, I'm back after a hiatus forced by a move. I've been digging into stereo recording methods again to see if I can pull it off on a shoestring budget, and in the process I discovered PZM-type microphones and ambisonic audio. Anyone have any experience with these? From what I've been reading (and hearing), PZM's seem to be pretty good at picking up natural room sounds, and I should be able to DIY a stereo pair for cheap. Ambisonic mics seem to be really good at capturing enough audio information to make the listener feel immersed in the sound, kinda feels like when I'm playing a symmetric setup with the guitar wedge cabinet added, and I can DIY a decent one for around $100 bucks.

Hi Guys

One of the microphones Physics refers to is a type that most people will be unfamiliar with. It is essentially a flat surface with a microphone in the middle of the area. There are many reasons for this design to exist, but how well it achieves any of those goals depends on where it is used.

The flat panel makes the mic almost unidirectional as any sound from behind the capsule is blocked. You can mimic this effect simply by placing a conventional mic against a wall, maybe with some damping material to fill in the distance between the front and rear of the microphone body. The pickup may in fact be hemispherical - a half sphere, so something between hard directionality and a cardiod pickup pattern.

The flat panel will block room reflections and other noise from behind the microphone, possibly contributing to a "cleaner" primary sound pickup. This has the potential to make the recording less lively, or less representative of an audience member's experience.

Regarding "band mixes" versus "individual instrument tracks":

The Beatles are a well-known example of a band that played live together very intensely prior to making any recordings. This experience made them very tight musically, and everyone knew the material very well and knew how their equipment worked best. They could go into a studio and play as a band and lay down tracks very quickly and have the mix be as they wanted it to be.

Of course, the first recordings were mono, as that was the style of the era. Radio play was the primary aim, along with selling singles and records to a youthful audience who mostly had mono playback equipment at home. Stereo was not a concern in dance halls.

As recording and playback equipment evolved, so too did the band's financial reach. More studio time could be allotted and more recording tracks on tape combined with stereo mastering lead to more experimentation in the studio. This lead to some interesting results - maybe some songs that could not be played live - and to less beneficial results that smacked of over-indulgence.

The demands made by broadcasters for more compressed mixes slowly crept into what was done in the studio, as we've described above. The modern use of ipods and similar devices has greatly deteriorated the sound quality and there is a whole generation of new music listeners who have never experienced good sound fidelity. Digital is definitely not a panacea except that it allows diverse manipulation of the sound at a core level that was not possible with analog. As described elsewhere in TUTs and here, data compression and data reduction impairs fidelity while allowing more songs to be packed into a given package. To me, that is not a trade-off that I accept.

I always prefer band mixes, but there are also many excellent recordings using multitracking that retain the feel of the band playing together.