- Gale 04May16: @Wolfgang, thanks for struggling with the table. I would like to see "Region", "Timeperiod", "Curve Name, alias names" and "Code" as table headings, not sub-headings. Also the empty rows as dividers don't look good to me. I styled the top border of one row "solid thick red" as an example of what you could do to make the divisions look nicer. You can color the text differently too.
- Gale 10May16: Is this content ready now for integration into the article?
This page is a User "Work in Progress"
|Please let the claimant work with it at least two weeks after this sticker was put up (or until this sticker has been removed, if earlier).|
Suggestions may be made to the claimant by clicking on the page's "discussion" tab.
|This page serves as a library of additional EQ curves for old disc recordings that can be used in the Equalization effect in current Audacity.
The audio on almost every phonograph record is not the same as the one once performed. For technical reasons the signal had to be modified before the discs were cut. Playback equalization (EQ or de-emphasis) will modify the signal back to original. Only by this music lovers can enjoy the original sound of the music performed long ago from their rare discs.
The most relevant EQ curves are presented as Table1
- You can download some of them from LIBRARY and import them into Audacity
- You can generate them yourself with “78 rpm EQ Curve Generator”
- You can set the sliders of any digital or analogue graphic equalizer manually
- You can determine appropriate settings for any adjustable analogue pre amplifier.
Which EQ curve will be needed for a specific record label is answered
- for 78 rpm shellacs in table 2
- for early LPs in table 3
Equalization (EQ) Curves Explained
When phonograph records are made, the sound being recorded is deliberately distorted by reducing the volume of the low frequencies and increasing the volume of the high frequencies. This process, known as 'pre-emphasis', allows the low frequencies to be accommodated in the limitations of the record groove and reduces the effect of high frequency surface noise. If pre-emphasis was not carried out, the bass notes in the music would create a groove in the record that oscillated so wildly that the stylus could jump out of it on playback, and the treble notes would be drowned out by the surface noise of the stylus in the groove.
On playback, the pre-emphasis must be reversed in order to restore the original sound. This is known as 'de-emphasis' or equalization (EQ).
Modern vinyl records use a method of pre-emphasis and de-emphasis adopted by the Record Industry Association of America (RIAA) in the 1950's, and the EQ curve used is known as the RIAA curve. However, before the RIAA curve was adopted, each record label used its own EQ curve for recording and, for these records (78rpm and early vinyl), the correct EQ curve must be used for playback.
Each 78rpm EQ curve is a combination of two filter characteristics; a bass boost curve, defined by a 'Bass Turnover' (or 3dB) frequency, and a treble cut curve, defined by a '10 kHz Gain Rolloff' parameter, i.e. a defined level of treble cut at 10 kHz.
As an example, Figure 1 below shows the characteristic of the bass boost curve defined by a 500Hz Bass Turnover, and Figure 2 shows the characteristic of the treble cut curve defined by a 10 kHz Gain Rolloff of -13.7dB. These two curves, when combined, give the characteristic shown in Figure 3.
Figure 1. Bass Boost curve: 3dB at 500 Hz
Figure 2. Treble Cut curve: -13.7 dB at 10 kHz
Figure 3. Combined Bass Boost and Treble Cut curve
The EQ curve may also include a Low Frequency Shelving filter, (although it is absent from the definition of most 78 rpm EQ curves). This addition reduces the effect of the bass boost at very low frequencies (typically 50 or 100 Hz) in order to attenuate low-frequency noise such as turntable rumble. Figure 4 shows the effect of a 50 Hz LF shelving filter being added to the curve in Figure 3. This is in fact the RIAA standard EQ curve.
Figure 4. Combined Bass Boost, Treble Cut and 50 Hz LF Shelving curve
Acoustically recorded (pre-electric) 78rpm records have a 'flat' EQ curve, i.e. with no bass boost or treble cut and, in some early electric EQ curves, while there is a bass boost curve, the 10 kHz Gain Rolloff is zero, i.e. there is no treble cut.
Note that in the combined EQ curve, the gains at the Bass Turnover frequency and at 10 kHz may be different from those specified by the parameters. This is not an error, but is due to fact that the gains of the bass boost and treble cut curves are simply added together.
Because 78 rpm EQ curves were non-standard and, in many cases, accurate records were not kept to show what EQ curves were used when recording 78s, there is a degree of uncertainty about what is the correct playback EQ for many record labels. The tables below have been obtained from websites which, in their turn, have compiled data from a number of sources and should prove reasonably accurate. However, the ear of the listener is the final arbiter - if it doesn't sound right, it isn't right!
According to NAB standards, the nominal speed of a 78 RPM record is precisely 78.26 RPM +/- 0.5%.
The most relevant EQ curves are presented in Table1. All curves are described from the point of view of a playback or de-emphasis curve, where bass / low frequencies must be amplified / boosted and where treble / high frequencies must be attenuated / cut in order to achieve the original sound that had been recorded. The corresponding pre-emphasis curve used for cutting the master disk is inverse. (When comparing with the lists provided by the manufacturers of equalizer preamps it should be considered that those may be misleading, as they might not quote the correct parameters of the curve but rather the next-best possible settings of these devices.)
Table1 gives the three parameters to characterize any EQ curve: the turnover frequency f1 for bass shelf, f2 for bass boost and f3 for treble cut (or alternatively the three corresponding time constants τ1, τ2 and τ3). These are the necessary conditions to compute and plot any EQ curve, determine the correct settings of a digital equalizer or to solder an electronic filter circuit.
The gain at two typical frequencies will give you a rough impression of what the curve does to the audio from the record. The frequencies are:
- 50 Hz, where usually the bass shelf becomes effective
- 10 kHz, because the treble curve is often indicated by rolloff at 10.000 Hz
The very descriptive “code” is a good tool to avoid misunderstanding when EQ curves come under various alias names (what they do too often).
- The first 3-digit number indicates the turnover frequency of bass boost (f2)
- The letter in the middle is
- N … (“No”) if no bass shelving is applied, or
- X … 12 dB (this is never used)
- C … 14 dB (possibly named C after Columbia LP curve)
- A … 16 dB
- B … 18 dB
- R … 20 dB (possibly named R after RCA or RIAA)
- The last number shows the reduction or rolloff of treble at 10 kHz and is always preceded by a minus sign. Please mind that this is only a code and that the exact value – after normalization to 0 dB at 1000 Hz – might be different.
This code can be used to find the correct settings of most equalizer preamps.
(Example: “RIAA 500R-13.7” means for the RIAA curve that bass must be boosted below 500 Hz, but no more than + 20 dB and that treble must be cut at 10.000 Hz to – 13.7 dB)
The geographic region and the time period are added to allow a qualified guess for the required EQ should a record label not be listed. In general, American recording curves were more deliberate in cutting bass and boosting treble. The British and Europeans tended to apply only the necessary minimum of bass attenuation and often no treble boost at all, that means they had a “flat” treble curve. Early pre-emphasis curves were simply built and rather soft. In the late years (after 1945) curves became highly sophisticated, with the third turnover frequency f1 added to manage the bass shelving and also with gain ranging from -20 dB to + 20dB.
Table 1: Playback Equalization Curves
|Region||Timeperiod||Curve Name, alias names||Time constants||Turnover frequencies||Bass shelf||Bass boost||Treble cut||Code|
|τ1 [μs]||τ2 [μs]||τ3 [μs]||f1 [Hz]||f2 [Hz]||f3 [Hz]||[dB]|| @ 50Hz
|Normal Groove, 78 rpm|
|Eur., Brit.||1926 - 1946||"European 78", Old Europ., 250, EMI 78||636||250||+ 14||0 (flat)||250N-0|
|Europe||1926 - 1950||"European 500"||318||500||+ 19||0 (flat)||500N-0|
|America||1926 - 1951||"American 78"||636||250||5792*||+ 14||- 6||250N-6|
|America||1926 - 1951||"American 78"||636||250||4340*||+ 14||- 8||250N-8|
|Amer.(CBS)||1938 - 1948||"Columbia 78"||530||100||300||1592||+ 16,7||- 15,0||300N-16|
|Eur., Brit.||1944 - 1956||"DECCA 78"||531||25||300||6366||+ 11||- 5.7||300N-5.7|
|Germany||1952 - 1955||"CCIR 78", Recomm. No.134 (1953) ||450||50||354||3183||+ 17,0||- 10,5||350N-10.5|
|Eur., Brit.||1955 - end||"IEC N78" = "B.S.1928" for N78||3180||450||50||50||354||3183||+ 16||+ 14,0||- 10,5||350A-10.5|
|Microgroove, 33⅓ & 45|
|America||1942 - 1949||NAB (broadcast transcriptions, 1942)||318||100||500||1592||+ 20,5||- 15,6||500N-16|
|America||6/1948 - 1956||"Columbia LP", Columbia 33, "LP" ||1590||318||100||100||500||1592||+ 14,5||+ 13,6||- 15,5||500C-16|
|America||4/1949 - 1958||"NAB", NARTB (standard 1949)||3180||318||100||50||500||1592||+ 20||+ 17,5||- 15,6||500"B"-16|
|America||1/1951 - 1958||"AES" (standard 1951)||397,9||63,7||400||2500||+ 18,1||- 12,3||400N-12|
|Amer.(RCA)||8/1952 - pres.||"RCA New Orthophonic"||3180||318||75||50,05||500,5||2122||+ 19,5||+ 16,9||- 13,7||500R-13.7|
|Amer. (all)||ca.1956-pres.||= "RIAA" (US-standard since 1955)|
|Europe||ca.1962-pres.|| = IEC No.98 (1955)
= B.S.1928 (May 1955)
|Amer., Brit.||1949 - 1956||"LONDON LP", London ffrr, Decca ffrr ||1590||318||50||100||500||3183||+ 13,8||+ 12,5||- 10,9||500C-10.5|
|Germany||1955 - 1962(?)||TELDEC (as proposed 1957 for DIN)||3180||318||50||50||500||3183||+ 19,3||+ 16,5||- 10,9||500R-11|
|Brit., Eur.||1954 - 1958(?)||"EMI-HMV LP" , His Master's Voice LP||2274||318||63,7||70||500||2500||16,5 or 19||+ 16,7||- 12,6|
- Table1 is mostly based on Tab. 2a of: Heinz O. Graumann, Schallplatten-Schneidkennlinien und ihre Entzerrung, in: FUNKSCHAU 1958 / Heft 15, pp 359 ff
- * computed frequencies to get 6 or 8 dB @ 10 kHz
-  CCIR used by Deutsche Grammophon modified with 50 Hz bass shelving => IEC N78 [Brice]
-  Used by British Decca and for London/Decca releases in US, mostly M33
-  Gary A. Galo, The Columbia LP Equalization Curve, ARSC conference March 2008; Gary A. Galo, Disc Recording Equalization Demystified, in ARSC Journal Fall 1996
78 rpm EQ Curve Generator
EQ Curves for Audacity can be generated from these Frequency and Rolloff values using the experimental Nyquist plug-in "78 RPM EQ Curve Generator". This plug-in is obtainable from the top of this Forum topic and requires Audacity 1.3.13 or later. Please give feedback on this plug-in, or ask for help if you need it, by replying to that Forum topic.
- Extract 78EQCurveGen.ny from the zip file downloaded from the above Forum topic.
- Place 78EQCurveGen.ny in the "Plug-Ins" folder inside the Audacity installation folder, then launch or restart Audacity. For more help installing the .ny file to the correct location, click here.
- Click . You can find help inside the plug-in by choosing one of the Help options in "Select Function or Help".
- Choose the curve you want from one of the lists.
- Enter the values for your chosen curve for
- "Bass Turnover Frequency (Hz)"
- "10 kHz Gain Rolloff (dB)"
- "LF Shelving Frequency (Hz)" (if a value is given)
in the equivalent boxes in the plug-in dialog.
- Click "OK" in the plug-in to save the .xml file to your chosen location.
- Select some audio and choose .
- Choose "Save/Manage Curves...".
- Choose "Import...", navigate to the location where you saved the .xml file from 78EQCurveGen.ny, then "Open".
- Click "OK".
Acoustic Recordings (before 1926) are beyond the scope of this page. In these pioneer years speeds varied from 70 to 90 rpm, groove modulation could be lateral, vertical or diagonal and some records were even cut outward with the audio starting at the center. A special turntable and a range of styli / needles are needed to replay. All acoustics were recorded without any pre-equalization (“flat”), simply because a modulation of the signal was impossible before electric microphones and amplifiers came into use. So the signal on the disc has a clean constant-amplitude characteristic. This is fine as long as you play back with a gramophone needle or a piezoelectric crystal pickup. But you will probably use a magnetic cartridge which – by its constant velocity characteristic – will double the amplitude whenever the frequency doubles. To compensate this Robinson (MidiMagic) recommends a “800N-16” EQ curve, which comes close to the theoretical characteristic of a constant velocity device – a straight line from +20 dB at 100 Hz to -20 dB at 10,000 Hz with constant slope of 6 dB/octave. On Audacity’s Equalizer a very simple “curve” to set!
- MidiMagic  gives useful information on vintage labels as Edison, Berliner, Pathé or Zonophone and playback EQ recommendations.
- Scientific help regarding valuable historic recordings can be found at
- iasa (International Association of Sound and Audiovisual Archives)
- and at ARSC (Association for Recorded Sound Collections).
Broadcast Transcription Discs are not in the focus of this page either. Those were recordable lacquer discs, mostly 16 inch in diameter, played at 33⅓ or 78 rpm. They were professionally used by radio broadcasters. In America many of these discs were recorded under the standard of the National Association of Broadcasters (NAB) of 1942. The very same recording curve had been used by NBC under the name “Orthacoustic” since mid 1930s. This “NAB Transcription (1942)” playback EQ setting can be downloaded here LINK
British BBC used a rather exotic curve as a house standard. The version in use after 1949 has been reconstructed from Longford-Smith’s publication of 1952 as an Audacity EQ setting “BBC Transcription (1949)” and can be downloaded her LINK
78 rpm Shellac Labels and Their EQ
This page is about electrical recordings since 1925 on 78 rpm discs made of shellac! The invention of the Electrical Recording System by Bell Laboratories / Western Electric which was licensed to industry leaders Columbia Records and Victor set some de-facto standards: speed is always 78.26 rpm, cut is always lateral (same as modern LPs) and the groove type is always Normal Groove (also named coarse groove). Therefore shellacs are sometimes referred to as N78 (which stands for normal groove discs, played at 78 rpm). A turntable capable of 78 rpm will be useful. You will need a MONO stylus with 2.5 mil (64 μm), for early electricals possibly one with 3 mil (76 μm) and this Audacity Wiki! It is assumed that you replay your discs “flat” (without any analogue de-equalization) and apply the necessary EQ after digitalization with Audacity.
In case sources did not agree on one EQ curve, their different opinions are listed and you will have to trust your ears.
Table 2: 78 rpm Shellac Labels and Their EQ (beta 2016 May 19)
|Label||Remarks||Curve Name||Code|| turnover
| treble rolloff
[dB @ 10kHz]
|_Electrical 78's (general)||1925-1938||300||0||ES|
|_Electrical 78's (general)||1932-1938, mid 30s||500-FLAT||500N-0||500||N||0||ia,ES,JP,RF|
|_Electrical 78's (general)||1938-1946||300 or 500||0 or -5||ES|
|_Electrical 78's (general)||1947-1954||300 or 500||-16||ES|
|Aco||1926 - 1933, with M in a circle||BBC 2dB/oct.||PC|
|Aeolian-Vocalion||1926 - 1933, with M in a circle||BBC 2dB/oct.||PC|
|American Rec. Co.||500||?||PC|
|Ariel||1925 - 1931 UK, with Δ after matrix no. or with W in a circle||[W.E.]||250||W.E.mike||PC|
|Beltona||1926 - 1933, from cat. 1194 to 1282, with M in a circle||BBC 2dB/oct.||PC|
|Beltona||1944 - 1955, ffrr, prod. by Decca UK,||Decca 78||300N-5.5||300||N||-5,7||PC|
|Bluebird||sub-label of RCA, see: RCA-Victor||ES|
|Bluebird||1925 - 1931, with VE in an oval or "Orthophonic Recording" or with Δ after matrix no. (recorded in Europe)||[W.E.]||250||W.E.mike||PC|
|Bluebird||1932 - 1949, with High Cut at 8500Hz||500-FLAT||500||0, later -12||PC|
|Broadcast||1926 - 1933, with M in a circle||BBC 2dB/oct.||PC|
|Brunswick||1944 - 1955, ffrr, a Brit. Decca label||Decca 78||300N-5.5||300||N||-5,7||PC|
|Brunswick||1946 - 1954||630N-12||629||-12||ES|
|Capitol||1942 (founded) to 1951||American 78||250N-8||250||N||-8||mm|
|Capitol||1942 - ?; probably "Capitol 400N-12.7"||[CAP]||400||-12||ia,ES,mil,JP,RF|
|Capitol / Capitol Cetra||1951-1955||Capitol [CAP]||400N-12.7||400||N||-12,7||mm|
|Capitol - Telefunken||500-FLAT||500N-0||500||N||0||ES,mil|
|Capitol (Europ.)||1944 - 1955, ffrr, prod. by Decca UK, matrix prefix DCAP||Decca 78||300N-5.5||300||N||-5,7||PC|
|Cetra||founded 1930s by RAI, Italy||European 78||250N-0||250||N||0||GH|
|Cetra-Soria||founded 1949, Cetra prod. in US||European 78||250N-0||250||N||0||mm|
|Chappell||1931 - 1944, with © before matrix no., [Bc]||Blumlein300||300N-0||300||N||0||PC|
|Coliseum||1926 - 1933, with M in a circle||BBC 2dB/oct.||PC|
|Columbia (American)||1926 [W.E.]||American 78||250N-5||250||N||-5||ES,mil|
|Columbia (American)||1926 [W.E.]||200||-7||ia,mil,JP,RF|
|Columbia (American)||1926 - 1940 (?) [W.E.]||American 78||250N-8||250||N||-8||mm|
|Columbia (American)||1938 - end, most ("Columbia Rec." a CBS label since 1938)||Columbia 78||300N-16||300||N||-16||ia,GH,ES,mil,mm,JP,RF|
|Columbia (British)||1925 - 1931, with W in a circle||[W.E.]||250||W.E.mike||PC|
|Columbia (British)||from 1926, from 1931 EMI(UK) - 1953||European 78||250N-0||250||N||0||ia,GH,ES,JP,RF|
|Columbia (British)||1931 - 1944, with © before matrix no., [Bc]||Blumlein300||300N-0||300||N||0||PC|
|Columbia (British)||1932 - 1949, with W in a circle or matrix prefix W (US COL/OKeh reissues)||500-FLAT||500||0, later -12||PC|
|Columbia (British)||1949 - 7/1953, EMI UK, matrix nos. from CA22600 to CA22610, and at CAX11932||500-FLAT||500N-0||500||N||0||PC|
|Coral||1946 - 1954||629||-12||ES|
|Decca (American)||1934 -, (Decca US established in 1934)||AES||400N-12||400||N||-12||ia,JP,RF|
|Decca (American)||pre 1946||Blumlein300||300N-0||300||N||0||ES|
|Decca (American)||very few, to try a combination of 500Hz / 6300 Hz||500N-5.5||500||N||-5,5||mm|
|Decca (American)||1946 - 1951||Decca 78||300N-5.5||300||N||-5,7||mm|
|Decca (American)||1946 - 1954 (??? 629 Hz ???)||629||-12||ES|
|Decca (American)||1951 - 1953||AES||400N-12||400||N||-12||mm|
|Decca (American)||1953-Nov 1955||NAB||500B-16||500||B||-16||mm|
|Decca (British)||1935 - 1944, matrix up to DR8485-2; test disc: Decca K.1803, London T.4997||Blumlein300||300N-0||300||N||0||PC|
|Decca (British)||to 1944||European 78||250N-0||250||N||0||ES,mm|
|Decca (British)||1944 - 1955, ffrr, cat. nos. from F.8440, K.1032, M.569 and X.281 (some exceptions); matrix nos. 8486 to 18000; test disc: Decca K.1802, London T.4996||Decca 78||300N-5.5||300||N||-5,7||PC|
|Decca (British)||1944 - 1956 (to DR8485-2)||Decca 78||300N-5.5||300||N||-5,7||ES,mm|
|Decca (British)||some 1949-1956||London||500C-10.5||500||C||-10,5||mm|
|Decca (European)||to 1944||European 78||250N-0||250||N||0||mm|
|Decca (European)||1944-1950||Decca 78||300N-5.5||300||N||-5,7||ES,mm|
|Decca (European)||1950-1954, (Telefunken + Decca UK = TELDEC since 1950)||Telefunken||400N-0||400||N||0||mm|
|Decca (European)||some 1954-1962||CCIR 78||350N-10.5||354||N||-10,5||mm|
|Decca ffrr||1946, same as London ffrr||Decca 78||300N-5.5||300||N||-5,7||ia,mil,JP,RF|
|Deutsche Grammophon||alias "DGG", taken over by Telefunken 1937||300||-5||ES,mil|
|Deutsche Grammophon||1944 ca. - 1953 ca. (???)||European 78||250N-0||250||N||0||PC|
|Dial||78s used same EQ as 33⅓ and 45s||Columbia LP||500C-16||500||C||-16||ES,mil|
|EMI-HMV (British)||some, re-releases of acoustics mastered 1909-1926||800N-12||800||N||-12||mm|
|EMI-HMV (British)||1927 - 1953, prod. by EMI(UK)||European 78||250N-0||250||N||0||GH,ES,mil,mm|
|EMI-HMV (British)||1931 - 1944, with □ after matrix no., [Bc]||Blumlein300||300N-0||300||N||0||PC|
|EMI-HMV (British)||1931 - 1949, with ◊ after matrix no.||500-FLAT||500||0, later -12||PC|
|EMI-HMV (British)||1931 - 1953, (test disc HMV DB4037)||European 78||250N-0||250||N||0||ia,ES,mil,JP,RF,PC|
|EMI-HMV (British)||11/1943 - 7/1953, matrix nos. from 2EA17501 to 0EA17576||European 78||250N-0||250||N||0||PC|
|EMI-HMV (British)||1955 - end, test disc: EMI JGS812, BBC DOM86||CCIR 78||350N-10.5||354||N||-10,5||PC|
|Exclusive||all, 1944 - 1949||Decca 78||300N-5.5||300||N||-5,7||mm|
|Gramophone Company||1925 - 1931 UK, with Δ after matrix no.||[W.E.]||250||W.E.mike||PC|
|Harmony Acoustics||to Aug 1929||300||-16||mil|
|His Master's Voice (Brit.)||some, re-releases of acoustics mastered 1909-1926||800N-12||800||N||-12||mm|
|His Master's Voice (Brit.)||1925 - 1931 British, with Δ after matrix no.||[W.E.]||250||W.E.mike||PC|
|His Master's Voice (Brit.)||1927 - 1953, prod. by EMI(UK)||European 78||250N-0||250||N||0||ia,GH,mm,JP,RF|
|His Master's Voice (Brit.)||1932 - 1949, with ◊ after matrix no.||500-FLAT||500||0, later -12||PC|
|His Master's Voice (Brit.)||11/1943 - 7/1953, EMI UK, matrix nos. from 2EA17501 to 0EA17576||500-FLAT||500N-0||500||N||0||PC|
|Hispanophone||1926 - 1931 , with Δ after matrix no.||[W.E.]||250||W.E.mike||PC|
|Hit of the Week||1930 - 1932||500||-5||ES,mil|
|Homochord||1926 - 1928, matrix no. HH, JJ, HR, JR, Ee (made by Gramophone Co.)||[W.E.]||250||W.E.mike||PC|
|Hugophone||1925 - 1931, with W in a circle||[W.E.]||250||W.E.mike||PC|
|Hugophone||1931 - 1944, with © before matrix no., [Bc]||Blumlein300||300N-0||300||N||0||PC|
|Linguaphone||1926 - 1933, with M in a circle||BBC 2dB/oct.||PC|
|L'Oiseau-Lyre||1944 - 1955, ffrr, prod. by Decca UK,||Decca 78||300N-5.5||300||N||-5,7||PC|
|London||early , 1947-1948 ?||European 78||250N-0||250||N||0||mil|
|London||1947 - 1955, ffrr, prod. by Decca UK,||Decca 78||300N-5.5||300||N||-5,7||PC|
|London ffrr||1949, same as Decca ffrr (to DR8485-2)||Decca 78||300N-5.5||300||N||-5,7||ia,mil,JP,RF|
|MacGregor||to 1965?||American 78||250N-8||250||N||-8||mm|
|Mercury||to 1951||American 78||250N-8||250||N||-8||mm|
|Mercury||1951 - Oct 1954; to matrix MG50026, 7000||AES||400N-12||400||N||-12||ia,ES,mm,JP,RF|
|MGM (American)||founded 1946; up to E3071||MGM [MGM]||500N-12||500||N||-12||ia,ES,mil,JP,RF|
|MGM (British)||1949 - 7/1953, matrix no. 0SM420||500-FLAT||500N-0||500||N||0||PC|
|Musicraft||700 or 750||-14||ES,mil|
|Nat. Gramophonic Soc.||1926 - 1933, with M in a circle, cat. HHH to TTT and NGS.65 to NGS.102||BBC 2dB/oct.||PC|
|Octacros||1931 - ?, Britain, a Synchrophone label||Blumlein300||300N-0||300||N||0||PC|
|Odeon||some early electricals||800||0||ES,mil|
|Odeon||1925 - 1928, with W in a circle (a Lindström label)||[W.E.]||250||W.E.mike||PC|
|Odeon||1928 - 1936, matrix with ₤ in a circle ( a Lindström label)||400||100Hz||0||PC|
|Odeon||1931 - 1944, with © before matrix no., [Bc]||Blumlein300||300N-0||300||N||0||PC|
|Odeon||to 1953, (1926 sub. of Brit. Columbia , 1931 sub. of EMI)||Blumlein300||300N-0||300||N||0||ES,mil|
|OKeh||1926 - 1941 (a Columbia label since 1926)||American 78||250N-8||250||N||-8||mm|
|OKeh||electricals, probably American78 250N-8||300||0 or -8.5||ES,mil|
|Parlophone||1925 - 1931, with W in a circle||[W.E.]||250||W.E.mike||PC|
|Parlophone||1925 - 1953||European 78||250N-0||250||N||0||GH,ES|
|Parlophone||1931 - 1944, with © before matrix no., [Bc]||Blumlein300||300N-0||300||N||0||PC|
|Parlophone||1932 - 1949, with W in a circle or matrix prefix W (US COL/OKeh re-issues for UK)||500-FLAT||500||0, later -12||PC|
|Parlophone||1949 - 7/1953, EMI UK, matrix nos. from CE14643 to CE14689||500-FLAT||500N-0||500||N||0||ia,PC,JP,RF|
|Parlophone-Odeon||1925 - 1928, with W in a circle, Odeon in Brit.||[W.E.]||250||W.E.mike||PC|
|Parlophone-Odeon||1928/29, matrix with ₤ in a circle, Odeon in Brit.||400||100Hz||0||PC|
|Pathé||1931 - 1944, with © before matrix no., [Bc]||Blumlein300||300N-0||300||N||0||PC|
|Polydor||sub-label of Deutsche Grammophon||300||-8,5 or -10||ES,mil|
|RCA Victor||12/1931 - 2/1932 "long-playing" shellacs at 33⅓ rpm||500 - 700||0||PC|
|RCA Victor||1931/2 "long-playing" shellac, N-groove played at 33⅓||American 78||250N-6||250||N||-6||mm|
|RCA Victor||1931 - , test disc Victor84522||500-FLAT||500N-0||500||N||0||PC,ES|
|RCA Victor||1931 - ?, with swastika after matrix no., (EMI reissues)||European 78||250N-0||250||N||0||PC|
|RCA Victor||1931 - 1941||American 78||250N-6||250||N||-6||mm|
|RCA Victor||1931 - 1944, with □ after matrix no., EMI UK reissues, [Bc]||Blumlein300||300N-0||300||N||0||PC|
|RCA Victor||1935||300 or 500||-5||ES|
|RCA Victor /Victrola||1932 - 1949, with High Cut at 8500Hz||500-FLAT||500||0, later -12||PC|
|RCA Victor||1938 (or earlier), used High Cut at 8500Hz||Old Ortho.||500N-12.3||500||N||-12,6||PC|
|RCA Victor||1938 - 1947||500||-7||ia,JP,RF|
|RCA Victor||1938 - 1948||500||0 to -12||mil|
|RCA Victor||1938 - 1954||500||-8||ES,mil|
|RCA Victor||1941 - 1947 (some to Sept 1952)||Old RCA||800N-8||800||N||-8||mm|
|RCA Victor||1947 - 1951||RCA 45||800N-12.3||800||N||-13,8||mm|
|RCA Victor||1947 (or 1950) - Aug 1952||Old Ortho.||500N-12.3||500||N||-12,6||ia,mm,JP,RF|
|RCA Victor||RIAA after 8/52, after matrix E2RP4094||RIAA||500R-13.7||500||R||-13,7||ES|
|RCA Victor (European)||1930 - 1950||European 78||250N-0||250||N||0||ES|
|Regal||1925 - 1931 UK, with W in a circle||[W.E.]||250||W.E.mike||PC|
|Regal Zonophone (Brit.)||budget label of EMI/Columbia||European 78||250N-0||250||N||0||ES,mil|
|Regal Zonophone (Brit.)||1925 - 1931 UK, with Δ after matrix no. or with W in a circle||[W.E.]||250||W.E.mike||PC|
|Regal Zonophone (Brit.)||1931 - 1944, with © before matrix no., [Bc]||Blumlein300||300N-0||300||N||0||PC|
|Regal Zonophone (Brit.)||1932 - 1949, with W in a circle or matrix prefix W (US COL/OKeh reissues for UK)||500-FLAT||500||0, later -12||PC|
|Regal Zonophone (Brit.)||1949 - 7/1953, matrix no. CAR6800||500-FLAT||500N-0||500||N||0||PC|
|Scala||1926 - 1933, with M in a circle||BBC 2dB/oct.||PC|
|Supraphone||Czech, since 1932, a subsid.of Ultraphon||Telefunken||400N-0||400||N||0||ES,mil|
|Synchrophone||1931 - ?, Britain||Blumlein300||300N-0||300||N||0||PC|
|Technichord||American, all N78 from 1938 [TCH]||Technichord||800N-12||800||N||-12||ES,mil,mm|
|Telefunken||1944 - 1955, ffrr, prod. by Decca UK,||Decca 78||300N-5.5||300||N||-5,7||mm,PC|
|Telefunken||1951-1953, (Telefunken + Decca UK = TELDEC since 1950)||Telefunken||400N-0||400||N||0||mm|
|Theme||all N78||American 78||250N-6||250||N||-6||mm|
|Turicaphon||Switzerland, 1930 - , a subsid.of Ultraphon||Telefunken||400N-0||400||N||0|
|Ultraphon||Europe 1929-1932, taken over by Telefunken||Telefunken||400N-0||400||N||0||ES,mil|
|Unison||1926 - 1933, with M in a circle||BBC 2dB/oct.||PC|
|Victor||1925 [W.E.]||200 - 500||-7||ia,JP,RF|
|Victor||1925 [W.E.]||250 or 300||0 or -5||ES,mil|
|Victor||1926 -1931 [W.E.]||American 78||250N-6||250||N||-6||mm|
|Victor / Victrola||1925 - 1931, with VE in an oval or "Orthophonic Recording" or with Δ after matrix no. (recorded in Europe)||[W.E.]||250||W.E.mike||PC|
|Victor||see: RCA-Victor (bougt by RCA in 1930)||ES|
|Vocalion||a Brunswick label, 1926 - 1940||European 78||250N-0||250||N||0||ES,mil|
|Vocalion||1926 - 1933, to cat. X10029 A.0269 and K05312, with M in a circle||BBC 2dB/oct.||PC|
|Vocalion||1944 - 1955, ffrr, prod. by Decca UK, series V1000||Decca 78||300N-5.5||300||N||-5,7||PC|
|Voice of the Stars||1931 - 1944, with © before matrix no., [Bc]||Blumlein300||300N-0||300||N||0||PC|
|Zonophone||1925 - 1931 UK, with Δ after matrix no.||[W.E.]||250||W.E.mike||PC|
|Zonophone||1931 - ?, with swastika after matrix no.||European 78||250N-0||250||N||0||PC|
|Zonophone||1931 - 1944, with □ after matrix no., [Bc]||Blumlein300||300N-0||300||N||0||PC|
- [CAP]... used its own “Capitol curve” 400N-12.7. Play back with “AES” 400N-12!
- [Bc] ... Due to changes in the setup of the Blumlein cutter the characteristic of the recordings could vary between 180 Hz-FLAT and 500 Hz-FLAT, resulting in +/- 4 dB at 50 Hz. Copeland suggests 300 Hz as an average value.
- [W.E.] ... Very early Columbia and Victor recordings (1926) used a bass turnover frequency of 250 or 300 Hz but their treble is described as “flat”. The perceived treble amplification was possibly only the result of resonant peaks of the early Western Electric condenser microphones used in recording. Background information is given in this PDF: PDF An experimental replay EQ curve for this microphone / pre-emphasis combination can be downloaded here: LINK
- [MGM] ... and Audiophile used a special “MGM curve” 500N-12. Play back with “RCA Old Orthophonic” 500N-12.3!
- [TCH] ... Technichord used its own “Technichord curve” 800N-12. Play back with “RCA 45” 800N-12.3!
- Hi ... High Fidelity Magazine, October 1955 with revised “Dialing Your Disks” table.
- ES ... Esoteric Sound  and the updated EQ list from the manual of their re-equalizer preamp  in which they also have very useful tips how to identify LPs by their matrix number (British London / Decca, American Decca, American Columbia, RCA Victor). Please mind that they quote settings of their device which have to be translated back into parameters of EQ curves.
- GH ... Graumann, Heinz; Schallplatten-Schneidkennlinien und ihre Entzerrung, in: FUNKSCHAU 1958, Heft 15, pp 359 ff
- ia ... iasa – International Association of Sound and Audiovisual Archives iasa-replay-eq 
- JP ... James R. Powell Jr., “Audiophile’s Guide to Phonorecord Playback Equalizer Settings”, in: ARSC Journal 20-1, Spring 1989, pp 14-23
- mil ... Millennia Music and Media Systems  and their list: MM Legacy Recordings 78 EQ Chart.pdf
- mm ... MidiMagic  is probably the most comprehensive and reliable websource. Data were researched in the 1970s and are based on publications of the 1950s.
- RB ... Richard Brice in PspatialAudio 
- RF ... Russell Fisher / W.A.M.S. (Wolverine Antique Music Society) 
- PC ...Peter Copeland, Manual of Analogue Sound Restoration Techniques, The British Library, 2014,  (Some of Copeland’s EQ curves and some of his sources are disputable!)
- Recommended analogue reference:
- James R. Powell, Jr. and Randall G. Stehle, "Playback Equalizer Settings for 78 RPM Recordings", Third Edition, Gramophone Adventures, Portage, MI, 1993, 2002, 2007.
- Fritz Langford-Smith, Radiotron Designer's Handbook, Wireless Press, Sydney, Fourth edition, 1952.
- James Moir, High Quality Sound Reproduction, Chapman & Hall Ltd., London, 1958
- Recommended analogue reference:
Early 33⅓ LP Labels And Their EQ
After the launch of the “long-playing record 33⅓ rpm” by Columbia in 1948 (which used vinyl discs and a narrower groove width – microgroove records or M33) record producers experimented a lot to fully exploit the potential of the new medium. Bass shelving came into use to limit the necessary bass boost in playback and – as a consequence of the extended frequency range – necessary gain reached values as high as +/- 20 dB. So recording characteristics varied considerably!
The “poor sound quality” of some early LPs is nowadays considered to be mostly a result of the wrong EQ in playback.
Standardization was reached with the “New Orthophonic” curve of RCA which was to become the world standard by the name of RIAA. In America most labels switched to RIAA around 1955 – Europe followed by 1962.
In case that sources did not agree on one EQ curve, their different opinions are listed and you will have to trust your ears. Later recordings on the labels listed should be all RIAA. The following label should have used only RIAA all the time: Bethlehem, Classic Editions, Chess, Clef, Composer Recordings, McIntosh, Montilla, New Jazz, Norgram, Prestige, Romany, Roulette, Savoy and Walden [High Fidelity Magazine, MidiMagic].
Table 3: Early 33⅓ LP Labels And Their EQ (beta 2016 May 3)
|Label||Remarks||Curve Name||Code|| turnover
| treble rolloff
[dB @ 10kHz]
|Allied||to 1958 (!)||Columbia LP||500C-16||500||C||-16||Hi,ES,mil,mm|
|American Recording Society||to 1958 (!)||AES||400N-12||400||N||-12||Hi,mm,JP|
|American Recording Society||(4095 / E2KP>9607||RIAA||500R-13.7||500||R||-13,7||ES|
|Concert Hall||Marked AES, E1KP/E2KP matrix||AES||400N-12||400||N||-12||ES,mil,mm,RF|
|Concert Hall (British)||to 1956 (or 1954)||London||500C-10.5||500||C||-10,5||Hi,mm,JP|
|Concert Hall (American)||to 1954, XTV matrix to 20386||Columbia LP||500C-16||500||C||-16||Hi,ES,mm,JP,RF|
|Contemporary||2001-02, 2501-02, 2505, 2507, 3501||AES||400N-12||400||N||-12||Hi,ES,mm,JP|
|Contemporary||after AP121 no such # in discography||RIAA||500R-13.7||500||R||-13,7||ES|
|Cook||to 1958?, regular mono records||500N-15||500||N||var. -12 to -15||ES,mm|
|Cook (binaural)||binaural: inside band -0 rolloff, outs.-11 dB||500||0 ins./-11 outs.||Hi,ES,mil|
|Coral||up to MG4400, (w/raised matrix)||700||-5||ES|
|Coral||est. 1949, to 1958? (a DECCA subsidiary)||NAB||500B-16||500||B||-16||Hi,mm,JP|
|Coral||400 or 750||-12 or -16||mil|
|Decca||(up to MG4400)(w/raised matrix)||700||-5 or -10||ES|
|Decca (American)||1953, 33⅓ and 45s||AES||400N-12||400||N||-12||mm,JP,RF|
|Decca (American)||1953 - Nov 1955, 33⅓ and 45s||NAB||500B-16||500||B||-16||Hi,mm,JP,RF|
|Decca (European)||most from 1954||RIAA||500R-13.7||500||R||-13,7||mm|
|Decca (European)||some 1954-1962||CCIR||350N-10.5||350||N||-10,5||mm|
|Decca ffrr||1951 -||300||-14||JP,RF|
|Decca ffrr||1953 -||???London||450||-10 or -11||JP,RF|
|Deutsche Grammophon||1952 - 1955, possibly modified with 16dB/50Hz bass shelf to IEC 78 / B.S.78||CCIR 78||350N-10.5||350||N||-10,5||GH,RB|
|Deutsche Grammophon||alias "DGG"||LP||-10||ES|
|Dial||1948-1954, 33⅓ and 45s||Columbia LP||500C-16||500||C||-16||ES,mil,mm,JP|
|Dial*||bass of EP 45s improved by 700Hz t/o||500||-16||ES|
|Dot||to 1958, 33⅓ and 45s||AES||400N-12||400||N||-12||mm|
|Elektra||EKL 2-15, 18-20, 24-26 (rel. 1952-55)||Bartok||630N-16||629||N||-16||Hi,ES,mil,mm,JP|
|Elektra||EKL 17, 22 (released 1954)||AES||400N-12||400||N||-12||Hi,ES,mm,JP|
|Elektra||EKL 16, 21, 23 (rel. 1955) and from 27 up||RIAA||500R-13.7||500||R||-13,7||Hi,ES,mm|
|EMI||from July 17, 1953||RIAA||500R-13.7||500||R||-13,7||ES|
|EMI-Angel||to 1952, Deutsche Grammophon sold in US||500N-16||500||N||-16||mm|
|Esoteric||(E2KP to 9607)||RIAA||-12||ES|
|Esoteric||ES 500,517 and EST 5,6||AES||400N-12||400||N||-12||Hi,ES,mil,mm,RF,JP|
|Esoteric||New (Oct 1955)||RIAA||500R-13.7||500||R||-13,7||Hi|
|Festival||to 1955||Columbia LP||500C-16||500||C||-16||ES,mil,mm|
|Folkways||all (1948 - 1955)||Columbia LP||500C-16||500||C||-16||Hi,ES,mm,JP,RF|
|Fraternity Records||up to F-1013||RIAA||0||ES|
|Good-Time Jazz||1, 5-8||NAB||500B-16||500||B||-16||Hi,ES,mm,JP|
|Good-Time Jazz||2, 4, 20 -; from Oct 1955, re-recording||RIAA||500R-13.7||500||R||-13,7||Hi,mm|
|Good-Time Jazz||3, 9-19||AES||400N-12||400||N||-12||Hi,ES,mil,mm,JP|
|Handel Society||to 1957||Columbia LP||500C-16||500||C||-16||ES,mil,mm|
|Haydn Society||to 1957; (ARL1173)#||500||-10||ES|
|Lyrichord||before 1953, (E0-E3 matrix)||400||-12||ES|
|Lyrichord||if "629" listed on jacket, "newer"||629||-16||ES,mil,JP,RF|
|Mercury||(MG10000 series-approx fit)||500||-10||ES|
|Mercury||1951 - Oct 1954, 33⅓ and 45s, ( E0LRC3981)#||Old Ortho.||500N-12.7||500||N||-12,7||ES,mil,mm,JP,RF|
|RCA Victor||from Aug 1952 -; (>E2RP4094) 33⅓ and 45s||RIAA||500R-13.7||500||R||-13,7||Hi,GH,ES|
|RCA Victor||to 1954||AES||400N-12||400||N||-12||Hi|
|Remington||to 1958? (up to 199-135)#||NAB||500B-16||500||B||-16||Hi,ES,mil,mm,JP,RF|
|Riverside||to Sept (?) 1955||AES||400N-12||400||N||-12||Hi,ES,mil,mm,JP|
|Stradivari||to 1958||Columbia LP||500C-16||500||C||-16||ES,mil,mm|
|Transradio||to 1958?||Columbia LP||500C-16||500||C||-16||Hi,ES,mm,JP|
|Urania||to 1954; most||Columbia LP||500C-16||500||C||-16||mil,mm,RF|
|Urania||224, 603, 7059, 7063, 7065-66, 7069||AES||400N-12||400||N||-12||Hi,ES,mm,JP,RF|
|Vanguard||411-42, 6000-18, 7001-11, 8001-04||AES||400N-12||400||N||-12||mm|
|Vanguard||411-22, 6000-18||Columbia LP||500C-16||500||C||-16||RF|
|Vanguard||411-42, 6000-18, 7001-11, 8001-04.||Columbia LP||500||-16||JP|
|Vanguard||411-22, 6000-18, 7001-11, 8001-04||COL* or 750||-16||mil|
|Vanguard||411-42, 6000-18, 7001-11, 8001-04, (up to XTV20386)||500||-16||Hi,ES|
|Vanguard||since ca 1954||RIAA||500R-13.7||500||R||-13,7||Hi|
|Vox||(up to XTV20386), PL8400)#||RIAA||NAB||ES|
|Vox||1948-1951 or labeled "LP"||Columbia LP||500C-16||500||C||-16||GH,mil,mm,JP|
|Vox||1951 - Oct 1954||NAB||500B-16||500||B||-16||Hi,mil,mm,JP,RF|
|Westminster||labeled AES; up to E2KP 9607||AES||400N-12||400||N||-12||Hi,ES,mil,mm,JP,RF|
|Westminster||to Oct 1955, up to XTV20386||Columbia LP||500C-16||500||C||-16||Hi,ES,mil,mm,JP,RF|
- For Remarks and Sources please see below Table 1.