915Hz Cut
In this procedure we fed a hot 915Hz sine tone (measuring 3.36v on my tiny Rat Shack auto-ranging digital voltmeter) from the CD player into the Device Under Test (DUT), noted the SPL of 915Hz showing on screen with faders flat then cut as much 915Hz as possible and jotted down the difference. The idea was that we would see how well an EQ performed on difficult feedback tones that fall between ISO centers. I picked 915Hz because it is pretty darn close to halfway between the 800 slider and the 1000 slider, making it tough to control. After applying this test two or three times it dawned on me that it didn't really tell us much about real world usage and that there were too many variables at play such as 1/3-octave filter depths being 10, 12, 15 or even 24dB down and whether or not there were notch filters included in the DUT. Still, we went ahead and kept this procedure in the sequence.
In other words, don't read too much into these results!
In the left column you see the amount of cut that the EQ was able to achieve at 915Hz by using either the two 800 and 1000Hz sliders or whatever notch filters were available. I didn't bother testing both graphic filters and notch filters added together.
| 37.6dB | Rane GE 30 'Cut Only' mode |
| 35.7dB | Klark Teknik DN9340 Helix using a parametric filter with Q=80 |
| 33.1dB | Presonus DEQ624 in +12/-24dB wide mode |
| 31.9dB | TDM 30GE-2 using a single notch filter |
| 30.3dB | Sabine GRQ 3101 with one FBX filter |
| 30.0dB | Sabine GRQ 3102 with one FBX filter |
| 27.9dB | Ashly GQX3102 |
| 25.6dB | Rane GE 30 boost/cut mode |
| 21.5dB | Lake Contour with parametric filter |
| 20.4dB | Presonus DEQ624 in +12/-24dB narrow mode |
| 20.2dB | Audient ASP231 wide mode |
| 18.9dB | Rane ME 60 |
| 18.1dB | Presonus DEQ624 ±12dB wide mode |
| 18.0dB | Ashly Protea II 4.24G |
| 17.6dB | Behringer DSP8024 |
| 16.5dB | dbx 480 using graphic filters. Notch filter choices were 900 and 950Hz, notch results not documented. |
| 15.2dB | BSS FCS-960 wide mode |
| 15.0dB | Peavey EQ31FX |
| 14.7dB | Audio Logic SC31 |
| 14.7dB | dbx 3231L |
| 14.7dB | Rane DEQ 60L proportional Q mode |
| 14.1dB | Klark Teknik DN27 |
| 13.9dB | IRP TEQ DG-4023 -20dB cut only mode |
| 13.5dB | Klark Teknik DN360 |
| 13.4dB | AB 231 |
| 12.9dB | Nady GEQ231 |
| 12.6dB | Audient ASP231 narrow mode |
| 12.6dB | BSS FCS-960 narrow mode |
| 12.4dB | Rane MQ320S 'Mojo' |
| 12.3dB | Behringer GEQ3102 |
| 12.0dB | Rane ME 30 [early unbalanced version] |
| 11.8dB | Rane DEQ 60L perfect Q mode |
| 11.4dB | ART HQ31 |
| 11.2dB | XTA GQ600 |
| 10.2dB | UREI 527-A serial #518 |
| 9.7dB | Yamaha Q2031B |
| 8.8dB | UREI 527-A serial #167 |
| 8.3dB | Presonus DEQ624 ±12dB narrow mode |
| 8.3dB | IRP TEQ DG-4023 ±10dB boost/cut mode |
| 8.0dB | dbx iEQ31 |
| 7.0dB | NEI 2711 |