What happened to Audio Quality in the Home? S. Linkwitz

[TitaniumTroy]

Ok, I shortened the title up a bit to make it fit in the topic subject box. http://www.linkwitzlab.com/ALMA%2714/Sound_quality.htm

Some of things that Mr. Linkwitz advocate's that stuck out to me are diffusion at the front of the room, and absorption at the rear. Speaker wise sealed not ported designs or better yet open baffle. Much more attention needs to be placed on speaker radiation patterns, speaker positioning, and room acoustics.

I heard his Orion speaker at AXPONA 2013, while I liked it's open baffle sound. The bass seemed slow, and the image size small in vertical dispersion. Being a Magnepan owner I prefer it's 6' ft wave launch and the True Ribbon Tweeter has 180' degree dispersion, lobes and all. Maybe it was the room acoustics that were off, however I would take the Zen Acoustics, YG Camel, Sony SS AR1 , Martin Logan Montis, and Focal Utopia Scalla over the Orion.

FYI my current room acoustics are tri corner bass traps floor to ceiling, all corners. QRD diffusors on the front wall and corner and side wall of the corner. With more diffusion soon to try on my ceiling, and perhaps side wall and rear wall. I believe he advocates more common room furnishing type items for acoustic treatment purposes. He also promotes thinking of the listening room as a wave guide not a box.


Here are 10 examples of highly rated loudspeakers, which are representative of the "high-end" today. All are very pricey except for the small KEF LS50 two-way speaker in the center.

There are some real engineering marvels amongst these speakers, like the MBL Radial Strahler. It is the only speaker amongst these that has constant directivity at all frequencies. Horizontally it is omni-directional – as in this graph - and thus would meet my criteria for a high sound quality speaker, but unfortunately it has vented ports for unnatural bass enhancement. Besides, some directionality, like in a dipole or cardioid, is advantageous because it increases the direct to reverberant ratio at the listening position.

With the exception of the horn speakers and the Magneplanar open-baffle radiator, all speakers here have ports. Also all use passive crossovers and external power amplifiers.

The Magneplanar uses large radiating panels and a long high frequency ribbon is not an acoustically small radiator and therefore has radiation lobes. It makes its interaction with the room difficult to predict. It also suffers in bass volume capability. Never-the-less it comes close to my ideal loudspeaker concept.

The horn loudspeakers next to it are highly directional, but their directionality varies considerably with frequency of radiation. They are multi-beamers. Thus the reverberant field in the room is relatively weak for most frequencies. To me they sound like big headphones at a distance, creating a phantom scene that is uncomfortably close and colored.

The TAD 3-way and KEF Blade use a coaxial design of midrange and tweeter, which gives a smooth transition in the polar pattern between the two transducers and a smooth roll-off in the off-axis response as the speaker becomes increasingly forward directional with higher frequency. Again, they are omnis at low frequencies.

Both speakers and most others hereuse strategically placed internal bracing to minimize spurious radiation from the enclosure surfaces. All the box speakers here must deal with the acoustic cavity behind the cone and how to dissipate the airborne energy that should not be re-radiated into the room.

The B&W 801 speaker goes for wide horizontal and vertical dispersion and low diffraction with its spherical midrange and tweeter baffles. But it does not go far enough to produce a neutral sounding reverberant field in the room.

The Dynaudio loudspeaker with its symmetrical vertical driver arrangement achieves a narrow vertical radiation pattern, but possibly with lobing.

The Spendor box speaker continues in the BBC tradition of monitor design and has in my opinion a host of cabinet and diffraction issues. Again it really exemplifies what is wrong with the box loudspeaker paradigm and its generic loudspeaker sound.

The best recognized of this type of box speakers is probably the Wilson line of speakers, to the point of having become status symbols.

 

[malsackj]

Subjective versus Objective ?

http://www.prosoundweb.com/article/subj ... is_it/live

Do we want to get more into the recording process on this. The big change has been in the way we record the performances. Looking at the move from two mics to create the stereo image to using mic's on each instrument and creating the stereo image on a mixer.

 

[malsackj]

Multitrack recording is a process where the tape is divided into multiple tracks parallel with each other. Because they are carried on the same medium, the tracks stay in perfect synchronisation. The first development in multitracking was stereo sound, which divided the recording head into two tracks. First developed by German audio engineers ca. 1943, 2-track recording was rapidly adopted for modern music in the 1950s because it enabled signals from two or more separate microphones to be recorded simultaneously, enabling stereophonic recordings to be made and edited conveniently. (The first stereo recordings, on disks, had been made in the 1930s, but were never issued commercially.) Stereo (either true, two-microphone stereo or multimixed) quickly became the norm for commercial classical recordings and radio broadcasts, although many pop music and jazz recordings continued to be issued in monophonic sound until the mid-1960s.

Much of the credit for the development of multitrack recording goes to guitarist, composer and technician Les Paul, who also helped design the famous electric guitar that bears his name. His experiments with tapes and recorders in the early 1950s led him to order the first custom-built eight-track recorder from Ampex, and his pioneering recordings with his then wife, singer Mary Ford, were the first to make use of the technique of multitracking to record separate elements of a musical piece asynchronously — that is, separate elements could be recorded at different times. Paul's technique enabled him to listen to the tracks he had already taped and record new parts in time alongside them.

Multitrack recording was immediately taken up in a limited way by Ampex, who soon produced a commercial 3-track recorder. These proved extremely useful for popular music, since they enabled backing music to be recorded on two tracks (either to allow the overdubbing of separate parts, or to create a full stereo backing track) while the third track was reserved for the lead vocalist. Three-track recorders remained in widespread commercial use until the mid-1960s and many famous pop recordings — including many of Phil Spector's so-called "Wall of Sound" productions and early Motown hits — were taped on Ampex 3-track recorders.

The next important development was 4-track recording. The advent of this improved system gave recording engineers and musicians vastly greater flexibility for recording and overdubbing, and 4-track was the studio standard for most of the later 1960s. Engineer Tom Dowd was among the first to utilize 4-track recording for popular music production while working for Atlantic Records during the 1950s[citation needed]. Many of the most famous recordings by The Beatles and The Rolling Stones were recorded on 4-track, and the engineers at London's Abbey Road Studios became particularly adept at the technique called "reduction mixes" in the UK and "bouncing down" in the United States, in which multiple tracks were recorded onto one 4-track machine and then mixed together and transferred (bounced down) to one track of a second 4-track machine. In this way, it was possible to record literally dozens of separate tracks and combine them into finished recordings of great complexity.

All of the Beatles classic mid-1960s recordings, including the albums Revolver and Sgt Pepper's Lonely Hearts Club Band, were recorded in this way. There were limitations, however, because of the build-up of noise during the bouncing-down process, and the Abbey Road engineers are still justly famed for the ability to create dense multitrack recordings while keeping background noise to a minimum.

4-track tape also led to a related development, quadraphonic sound, in which each of the four tracks was used to simulate a complete 360-degree surround sound. A number of albums including Pink Floyd's The Dark Side of the Moon and Mike Oldfield's Tubular Bells were released both in stereo and quadrophonic format in the 1970s, but 'quad' failed to gain wide commercial acceptance. Although it is now considered a gimmick, it was the direct precursor of the surround sound technology that has become standard in many modern home theater systems.

In a professional audio setting today, such as a recording studio, audio engineers may use 64 tracks or more for their recordings, utilizing one or more tracks for each instrument played.

The combination of the ability to edit via tape splicing, and the ability to record multiple tracks, revolutionized studio recording. It became common studio recording practice to record on multiple tracks, and mix down afterward. The convenience of tape editing and multitrack recording led to the rapid adoption of magnetic tape as the primary technology for commercial musical recordings. Although 33⅓ rpm and 45 rpm vinyl records were the dominant consumer format, recordings were customarily made first on magnetic tape, then transferred to disc, with Bing Crosby leading the way in the adoption of this method in the United States.

From http://en.wikipedia.org/wiki/History_of ... _recording


Most of these early recordings were released as mono versions as opposed to the stereo two track. With the bouncing on the multi tracks bringing everything down to one track and adding three more than you can see that true stereo was not out on our recordings into the 70's or later. Add in that the masters being bounced that some were not able to be easily brought back to the studio and edited into stereo because some of the masters were no longer available. Erased and written over??



Does a mixer with a pan to the left or right equal the stereo mic techniques in creating a sound that will pass as stereo? This is up to debate with the golden ear crowd? Most studies say that panning of the signal will be good enough to give you the stereo signal and position. With spaced pair there will be a signal delay between left and right. In ORTF the delay will be shorter because the mic's are seperated by 17 cm. With XY and MS the mic's are in the same space and should have no time delay.