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Third Generation 16/4/2 Mixer | |
Article from Home & Studio Recording, November 1984 |
Third Generation is a new name in audio equipment and the mixer reviewed here is part of a range that extends from a simple 6 into 2 model to an impressive 24 into 4 into 2 PA desk.
Constructionally, the mixer is fairly conventional; it's built on a steel chassis and sports solid hardwood endcheeks, the paintwork being metallic brown. Measuring 970 x 570 x 90mm, the overall effect is solid and quite stylish, the overall package weighing 22kg.
In order to make connecting up easy, the input and output sockets are mounted at the top of the front panel on an angled section and a multicore connector is fitted for PA use. Internally, the mixer is beautifully built, each channel being built on a separate PCB, and these are joined by ribbon cable bus bars carrying the power supply lines and the virtual earth mixing busses. This means that the channel PCBs may be removed without any unsoldering for servicing.
Featuring low impedance electronic balancing, the circuitry is mainly based around the 4558 dual op amp chip which performs reasonably quietly, and care has been taken to buffer all outputs onto the virtual earth busses to ensure smooth operation of the pan controls and to minimise crosstalk.
Four of the channels are fitted with line inputs for remix purposes and these channels also feature remix switches and EQ bypass switches. The format of 16/4/2 means that four channel recording can be easily accommodated but, additionally, the system allows the drum mix, for example, to be routed via one or two of the four subgroups so that the overall drum level can be controlled by one or two faders instead of perhaps ten or so. To look at the operation in more detail, let's first examine one of the input channels.
The input from the microphone connects into the mixer via a balanced XLR socket (or the multicore for stage use) and this is wired pin 3 hot, pin 2 cold and pin 1 ground in the usual way.
Next comes the gain control which is used to match the incoming signal level to the circuitry; a peak reading LED indicates overload caused by setting the gain too high, and the signal quality may be checked by using the PFL (Pre-Fade Listen) button to route any channel to the headphones.
A three band EQ system with shelving bass and treble controls and a sweep mid section is used, the treble control giving +/-20dB at 12.8kHz and the bass control +/-20dB at 50Hz. The mid section may be swept over the range 400Hz to 5kHz and +/-19dB of cut or boost may be applied.
On the four remix channels, pushbuttons select 'Mic' or 'Remix' and EQ bypass buttons are also fitted which make instant comparisons with the 'flat' sound easy.
In the auxiliary send department, most budget mixers give an echo send and a foldback output, but the Third Generation unit offers more flexibility. Like the well known Allen and Heath System 8 mixers, three auxiliary sends are fitted, one pre-fade, one post-fade and one which may be switched to either. This is a very sensible system as elaborate PA set-ups may require two separate pre-fade foldback mixes whilst the engineer mixing down a four track tape will probably need two post-fade effects sends.
The Pan control is used either to position the sound in the overall mix or to dictate which of a pair of subgroups receives a particular input channel. This is because one button selects a pair of subgroups and the Pan control must then be set fully left or fully right to route the signal to the required destination.
The two routing buttons select subgroups one and two, and three and four, but incorporate a system whereby when both buttons are deselected, the channel is routed directly to the main left and right outputs, bypassing the subgroups altogether.
This is fine providing that you don't try to mute a channel by not routing it to the subgroups, because it will just turn up at the main output - the only way to mute a channel is to take down the fader. All the faders by the way are 70mm carbon types and have a smooth feel without being sloppy.
Located directly behind VU meters one and two, this section incorporates the four subgroup level faders, their associated pan pots and the master auxiliary controls.
Each of the three auxiliary or 'cue' sends has a PFL button to aid setting up as have the returns which also have pan and routing controls.
Though there are three cue sends, there are only two returns, Cue 1 and Cue 2. Now I can understand the pre-fade or foldback cue not having a return, as foldback is generally a one way affair, but for my money they've picked the wrong ones as Cue 3, the committed effects send (post-fade), is the one missed out. This is not too serious, however, as most users tend to ignore returns altogether and route their effects directly to channel inputs so that the EQ section may be used to modify the sound of the effect output.
Each of the four subgroups is allocated to a moving coil VU meter and 0dB on the meters corresponds to 0dBm or 0.775 volts, which means that the mixer output must be attenuated if the meters are going to agree with those on your semi-pro or budget tape deck. The reason that this standard has been chosen is that for PA use, many power amps require this level of input drive in order to realise their full power output potential.
On mixdown, a pushbutton routes the left and right outputs to meters two and three so that the true output level can be monitored.
Both have auxiliary send outputs which are independent of the cue system and four band EQ is provided allowing individual tonal corrections to be made to left and right channels. Again, EQ bypass switches are fitted.
This EQ operates at 12.8kHz, 800Hz, 200Hz and 50Hz allowing a useful degree of correction to be applied to the overall mix.
In addition, a talkback mic input is fitted and this, apart from the obligatory level control, has pushbutton routing to any or all of the cue outputs and to the main left and right outputs.
The headphone output is switchable between the PFL bus and the main output and this is thankfully in stereo, which is invaluable in a recording situation for positioning sounds within a mix.
The main problem usually encountered with budget mixers is noise at high settings of the microphone gain controls and this can only be overcome by incorporating transformers, expensive specialist ICs or elaborate transistor circuitry, any one of which would add considerably to the selling price.
It's probably fair to say that most budget designs wring the last ounce of performance out of standard ICs and this Third Generation design is no exception, presenting as it does an equivalent input noise of -126dB, which is a typical figure for a well-designed semi-pro mixer.
The subjective output noise will depend largely on the efficiency of the microphones used and the sound pressure level being recorded. All the budget mixers that I've tried, this one included, produce unacceptable amounts of noise when recording quiet vocalists via a conventional dynamic mic. To get around this you can use a condenser mic which has a higher output than a typical dynamic mic, or build a couple of extra low-noise preamps such as the design featured in HSR August 84 for use in awkward situations.
The EQ section gives more than enough cut or boost within its specified range but as always, it is up to the operator not to overdo things. Three band EQs with sweep midrange controls are an excellent compromise between flexibility and price, but there is always a point in the lower mid band that you can't quite get to which is particularly important when you're trying to salvage a less than scintillating drum sound.
There are no insert points on the mixer (though it would not be beyond the scope of a competent DIY reader to add them) so patching in limiters or gates can be a problem.
This is basically a PA mixer which can also be used for recording rather than vice-versa, and this is borne out by the multicore connector and the lack of line inputs.
The finish is pretty good by budget standards, the only thing that I didn't like was the use of coloured plastic knobs; I prefer the types with coloured caps, but that's only a subjective comment. One advantage is that there are no caps to fall off and get lost.
In terms of sound quality, I don't think that you could ask much more from a design in this price range and the noise is really no better or worse than that produced by other competently designed budget mixers. That being said, it's really the price and facilities that will differentiate one mixer from another and this model does have a flexible three band EQ with extra four band EQ on the output and three auxiliary cue sends to its credit.
All the main connections are made by means of XLR sockets, apart from the auxiliaries and the remix inputs, and the multicore connector is an attractive feature for prospective PA users.
One curious thing is that the input sockets are numbered right to left rather than left to right and I can't think of any logical reason for this but it shouldn't pose any problems.
All in all, this is a well made piece of equipment that performs well within its price range and offers just about every facility that you could ask for in a PA mixer.
For recording, it's certainly adequate for four track use though there are some design shortcomings that make it less than ideal for this purpose, the main ones being lack of line or insert sockets. It is, however, definitely worth phoning the manufacturers and getting a quote for having these fitted if you're really interested, as it shouldn't add much to the cost.
Finally, it's British and it's made from pretty standard components, so if you do get a fault developing, you won't have to wait months for a new part.
The mixer also comes complete with a comprehensive manual which includes a lot of helpful advice for PA operators and home recordists.
The 16/4/2 mixer retails for £985.55 inc VAT.
Details on the full range of audio mixers are available from Third Generation Audio Products Ltd, (Contact Details).
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Review by Paul White
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