Insert (effects processing)

Insert (effects processing)

In audio processing and sound reinforcement, an insert is an access point built into the mixing console, allowing the user to add external line level devices into the signal flow between the microphone preamp and the mix bus.

Common usages include gating, compressing, equalizing and for reverb effects that are specific to that channel or group. Inserts can be used as an alternate way to route signals such as for multitrack recording output or line level direct input.

Inserts can be balanced or unbalanced. Typically, higher-end mixers will have balanced inserts and entry level mixers will have unbalanced inserts. Balanced inserts appear as a pair of jacks, one serving as the Send (out from the mixer) and the other serving as the Return (back to the mixer.) Balanced insert jacks can be XLR, TRS or Bantam TT.

Unbalanced inserts can also be a pair of jacks such as RCA or 1/4" TS (Tip Sleeve.) Again, one jack serves as Send and the other serves as Return.

Most modern entry level and medium format mixers use a single TRS jack for both Send and Return. This dual-purpose insert jack only has three conductors, and balanced lines need at least two conductors. Because two lines share the same three-conductor insert jack, its architecture is necessarily unbalanced, with the two circuits sharing a common ground. Of the mixers using this kind of dual-purpose insert jack, most are designed with Tip Send, Ring Return, though many can still be found with Ring Send, Tip Return. A very few mixers have both architectures present on the same mixer; Tip Send for input channels and Tip Return for mix groups.

Insert jacks are often normalized so that signal is passed through the jack if nothing is inserted but is interrupted when the jack is holding a plug. Inserts with two separate jacks will have normalizing such that the Return jack interrupts signal but the Send jack doesn't. The Send jack can always be counted on to send signal out to external devices. A refinement of the normalization of jacks is the presence on the mixer of an insert ON/OFF button which allows the user to patch into or around the inserted devices at will without having to physically disconnect the insert cables.

Unbalanced TRS inserts are normalized as well. The presence of a plug in the jack breaks normal internal signal flow, sending signal out to external devices and returning this signal to the channel. TRS jacks can be specially wired with Tip and Ring connected together at the insert end, and both conductors going to Tip at the distant end. This allows for tapping the insert point for its signal without interrupting signal flow inside the mixer. A less reliable method to achieve the same end is to insert a TS or TRS plug halfway into the insert until there is a springy 'click' feeling at which point the plug is contacting the signal within the insert jack but isn't breaking the normalized contact. The "half-click" method works fine until the insert cable is jarred or wiggled, causing staticky noise or a loss of signal within the channel.

Because of the combination of balanced external devices and unbalanced insert jacks, the process of inserting involves finding out which devices have which kinds of output configurations. Full electronic balancing needs a different cabling style than transformer balancing, which in turn needs a different cabling style than impedance balancing. Mistakes in the interconnection may make the inserted signal drop in level by 6dB or add hum and buzz or even overheat a balanced output circuit on the external device, decreasing its usable life.

Insert jacks themselves can be the source of intermittent signal problems. Internal jack contacts may get too loose over time and they may oxidize, impeding electrical conduction. Regular use of the jack helps keep oxidization down. The manufacturer using high quality jacks and good assembly practices helps reduce failures over time.

Another problem with TRS, TS and TT jacks that come in Send/Return pairs is that the Send jack and plug look just like the Return jack and plug. Cross-patching mistakes are possible, resulting in no signal passing through the insert.

Inserts on analog mixers appear in various locations in the signal flow, depending on the vision of the designer. Most inserts tap the signal after the mic preamp and after the HPF (if present.) Others tap the signal after the channel EQ and before the fader. A few tap the signal after the fader and before the mix buses. Many consoles offer a choice between two, three or four of the possible insert points by a combination of internal jumpers or links that a skilled technician can modify.

Digital consoles are often designed to allow the user to move the virtual insert point before or after the channel EQ and some allow the insert point to be placed after the fader and before the mix buses. These are 'soft' changes; the options depend largely upon the design of the mixer's user interface and the breadth of processing power devoted to the insert function.

Inserted devices can be connected in series to create a string of inserted devices. For instance, one could connect a gate, a compressor and an equalizer in series through the same channel's insert.

Some digital mixers allow multiple effects to be inserted virtually, still others allow multiple third party plugins to be used as virtual inserts.

Inserts might be found on mono mixer inputs, mono and stereo subgroups, auxes, main outputs and matrix outputs. They're rarely found on stereo line level inputs. EQs are commonly inserted on monitor mixer output mixes so that the monitor engineer can use his own wedge and the PFL/Solo bus to hear what the artist's wedge sounds like without having to climb on stage to check.

Electrically, inserts are found at a variety of signal levels. Some are -10dB consumer line level, others are nominally -6dB or -2dB or 0dB or +4dB. Most balanced inserts are at +4dB nominal level. Digital mixers might specify their inserts as -20dBFS which is similar in level to +4dBu nominal on an analog mixer, depending on the maximum headroom of the analog design. For optimum gain staging and the least amount of system hiss, inserted devices should be chosen with regard to the signal level they can handle and the signal level the mixer can handle. Best gain staging is achieved when both insert and inserted device match in level.

ee also

*Patch bay

External links

* [ Bink's mixer insert list.] Large text file of many mixers and their insert characteristics.

Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Insert — may refer to: *Insert (advertising) *Insert (effects processing) *Insert (film) *Insert key on a computer keyboard, used to switch between insert mode and overstrike mode *Insert (molecular biology) *Insert (SQL) *Another name for a tipped tool,… …   Wikipedia

  • Guitar effects — are electronic devices that modify the tone, pitch, or sound of an electric guitar, or condition or reroute the signal in some fashion. Effects can be housed in small effects pedals ( stomp boxes ), guitar amplifiers, guitar amplifier simulation… …   Wikipedia

  • TRS connector — 1⁄4 in TRS connector Trip …   Wikipedia

  • Balanced line — In telecommunications and professional audio, a balanced line or balanced signal pair is a transmission line consisting of two conductors of the same type, and equal impedance to ground and other circuits. [Young EC, The Penguin Dictionary of… …   Wikipedia

  • Pro Tools — Infobox Software name = Pro Tools logo = caption = Pro Tools LE 7.3 screenshot on Mac OS X developer = Digidesign latest release version = Pro Tools HD/LE 7.4 latest release date = November 7, 2007 operating system = Mac OS X Windows XP genre =… …   Wikipedia

  • Alesis Fusion — Infobox synthesizer image caption = Alesis Fusion 6HD synth name = Alesis Fusion 6HD/8HD synth manufacturer = Alesis Corp synthesis type = Sample Playback, Virtual Analog, FM and Physical Modeling polyphony = Dynamic processor allocation varies… …   Wikipedia

  • Oscar/Wissenschaft und Entwicklung — Der Oscar für Wissenschaft und Entwicklung (Academy Scientific Engineering Award) ist eine seit 1931 vergebenene Auszeichnung der Academy of Motion Picture Arts and Sciences und würdigt herausragende Leistungen auf dem Gebiet der… …   Deutsch Wikipedia

  • Operational transformation — Operation Transformation redirects here. For the cross media event, see Operation Transformation (TV series). Operational transformation (OT) is a technology for supporting a range of collaboration functionalities in advanced groupware systems.… …   Wikipedia

  • Database — A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality (for example, the availability of rooms in hotels), in a way that supports… …   Wikipedia

  • Mixing console — In professional audio, a mixing console, or audio mixer, also called a sound board, mixing desk, or mixer is an electronic device for combining (also called mixing ), routing, and changing the level, timbre and/or dynamics of audio signals. A… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”