Order of the Bath

One thing that complicates the running of church sound is the requirement for multiple mixes for different purposes. In addition to the output to the main speakers you often need a feed to the induction loop, a tape recorder and perhaps the crêche and other parts of the building. The requirements of each are slightly different, and to do this effectively you need more than just a splitter on the main outputs—some stereo, some mono, some with an “ambient” mic mixed in etc.
When looking at some church systems I was struck by the complexity and the involvement required by the operators. The most common arrangement I have seen for recording or a hearing-aid loop is complete separate mixes on auxiliary-sends. This requires the operator to be aware of two or more levels on every channel and, if they are doing it properly, monitoring each one separately each time something changes (even if you do have them ganged by using a post-fade auxiliary). There are too many opportunities for error doing it this way.

The “ambient” additions are what we use the last mixer group for (see my earlier post on Group Mixing for Church Audio). These are microphones for signals that you do not want to go out to the main loud-speakers and can include high level microphones suspended above the congregation to pick up the singing, perhaps a microphone or direct feed from the organ (because even an electronic one normally has its own speakers rather than go through the PA) and once I even had a radio microphone in the bell tower. This group is switched so that the “Send to Mix” button is not pressed and there are connections to the group output sockets.
There are other ways to achieve this result, for instance using a auxiliary-send (containing only the “ambient” channels), a direct-out socket if there is only one microphone or even a separate small mixer, especially if you have limited channels available on the main one.

So now you have four wires and you need to generate the right signals for your various destinations. When we first installed our system I built a custom distribution box using mixer modules and line drivers from a range of modular units sold by Maplin. This got to be less than reliable due to my poor construction skills and we had to find a better solution. When it became critical I discovered the perfect solution by browsing around the shops and internet—the Citronic Z-5DM. It is small, in a 1U rack mount, very good quality not disturbing the signals at a critical stage, versatile and modestly priced. It is intended for background music in bars and hotels where two different stereo sound sources are required in up to five different areas but there is no harm in employing it for a different purpose. There may be other brands but I haven’t come across any and you may need to go to a specialist supplier to get one. There are similar devices called matrix-mixers which offer multiple inputs and outputs but these are often too complex and quite expensive.

The way it is connected is to take your main desk output, left and right, into the Line 1 inputs and the secondary “ambient” mix, left and right (or split from a single output), into the Line 2 inputs. You can then adjust the level of these for each of the five zone outputs independently, select stereo or mono for each and connect to your outboard equipment and amplifiers as required. The outputs will work balanced or unbalanced as required and, as each one is driven separately at low impedance, the loading from one amplifier will not affect the others and the distances can be quite long allowing the use of powered speakers for instance.
A typical arrangement would be

• Zone 1 — Line 1 only, stereo, balanced outputs, to main amplifiers.
• Zone 2 — Line 1 only, two mono, balanced outputs, to powered speakers in the side aisles and transepts.
• Zone 3 — Line 1 and 2, one mono balanced output, to hearing aid loop amplifier. Adjust the relative levels to suit the user’s requirements.
• Zone 4 — Line 1 and 2, one mono balanced output, to 100V line amplifier for distribution to crêche, chapel and other small rooms.
• Zone 5 — Line 1 and 2, stereo unbalanced outputs, to compressor then on to tape and CD recorders. Preset the levels by monitoring the recording.

All the levels can be adjusted from the convenience of the mixing console area without having to touch anything in the amplifier rack, though once they are set they can generally be left alone. I am told that this sort of multiple output facility is now available on some mixing desks but what we have done here is a simple solution which can easily be retrofitted to an existing system.

This, as best as I can determine, is the current position in the UK.

VHF Radio Mics

The licence free (deregulated) frequencies are (MHz)
173·800*, 174·000, 174·200, 174·400, 174·600, 174·800*, 175·000*.
Older equipment may be using the 5 frequency set of
173·800*, 174·100, 174·500, 174·800*, 175·000* which, apart from those that are the same (marked *), can’t be mixed with the current set. I am told that, for reliable operation, you can only use four at once. The extra frequencies are there to avoid local interference problems. The relevant regulation is MPT 1311 which limits the power to 2mw and 180KHz bandwidth.

UHF Radio Mics

The licence free (deregulated) frequencies are (MHz)
Ch13 = 863.100, Ch14 = 863.900, Ch15 = 864.500, Ch16 = 864.900
They are usually switchable to find a free channel and are limited to 10mw and 300KHz bandwidth. Many available microphones for sale and hire also have channels 1 to 12 but these should not really be used without a licence. Despite being higher power and bandwidth than the VHF units, the performance is very similar in practice, but with a stricter “line of sight” requirement. Due to variations in the actual frequencies used, transmitters and receivers from different manufacturers are often not interchangeable.

US Radio Mic Frequencies

Grey imported equipment commonly has frequencies named by U numbers (MHz)
U1 = 801.375, U2 = 801.875, U3 = 803.125, U4 = 803.750, U5 = 804.500, U6 = 805.750.
These should not be used in the UK [unless licensed].

For all I know this may be a well known practice but, as I haven’t seen it elsewhere, I thought it worth publicising for others. It is used for big live concerts but not commonly on smaller systems.

I am talking here about medium sized churches (say 100-300 congregation) with sound systems that have an active operator. In most cases the microphone users can be separated into two distinct groups; the leaders speaking and the worship team singing and playing instruments. Some churches may have a separate system for each group; this often happens when the musicians organise their own PA, but here I am considering an integrated sound system with one mixer.

It struck me that there was a frequent requirement to switch from one section to the other so, for instance, during prayers you would want all the band off to reduce hum and other distracting noises and during singing the minister should be off so that he is not performing a solo. It is inconvenient and error prone to switch/fade all the mics separately so I wanted a way to control them as a group.

Mixers in the middle of the market come in two distinct types; live and studio. In simple terms, live mixers allow the setting of each channel and feeding it to a stereo output pair. Studio mixers have additional features designed for multi-track recording which normally you would think were not needed for a church service but they can be exploited to solve the problem above. How they work is that each input channel has a set of routing buttons to direct the signal either to the main mix or one or more recording tracks (called groups). There are usually four or eight in stereo pairs so there are three or five routing buttons including the main “mix” routing. Further across the desk are a set of group faders, usually in pairs, which control the master output level to each track. You can see from this how a multi-track tape recording is made. The feature that makes it useful for our application is that each group output or pair also has a “send to mix” button which does exactly what it says—sends the group output to the main mix controlled by the master fader(s).

So what we can set up is, for example, all leaders mics routed to groups 1/2 and all musician inputs routed to groups 3/4. Then we can fade up or down each section as a whole using the relevant group faders. The channel levels can all be preset to their optimum and all the operator is doing during the service is fading in the right group at the right time. To make it even easier, all the levels can be set so that the group faders are full up to the stop when live so there is no doubt where it should be positioned. I suggest colour coding the caption on each input to show which group it is routed to with corresponding colour captions on the group faders. You don’t use the group output sockets at all and, although it is possible, it is not helpful to have any channel routed to more than one group at a time or main mix.

In practice we use an 8 track desk and use the four group pairs for

• 1/2 (Blue) Leaders—lectern, pulpit, communion table, clip radio mics etc.
• 3/4 (Red) Band—instruments and solo singers
• 5/6 (Green) Choir
• 7/8 (Yellow) Other—see later
• Direct to Mix (White)—CD, tape player and video inputs

The reason for separating the choir from the band is mostly to do with timing, but also the band section is not required for hymns using the organ. Consider a normal service sequence … reading — song — sermon —: The operator sequence would be …

• During the reading have 1/2 up.
• As the song is announced fade up 3/4 so that it is ready for when the band starts playing
• They play the intro and the choir find their pages and stand up
• Just before the first word, fade up 5/6
• Then fade down 1/2. You could cross fade here with two hands but it is not necessary, there is plenty of time
• During the song you have 3/4 and 5/6 live. The choir/band balance can be fine tuned if necessary on the group faders
• As the song ends, fade up 1/2 to be ready for the minister
• Fade down 5/6 (not too quick, allow for natural resonance)
• Fade down 3/4 when done unless another song is due in which case leave them.

You see the sequence — always “up before down,” so there are always live mics. With practice this becomes second nature and allows for most unexpected things e.g. the minister’s mic is already live if he decides to ask for that last verse again, though if you have a worship leader who talks over the singing then they will need to be on the band group not the leaders one. Even on a recording the fades will seem natural and “up before down” means you never get dead air. While a group is off it can be reconfigured for the next item e.g. cutting the lectern and enabling the pulpit before the sermon.

What doesn’t work with our current desk (SoundCraft Spirit Studio LC 16, quite old now)—relatively minor problems:

• The Aux Returns (reverb and FX) are not routable so stay live direct to mix even when the band group is off sometime giving odd effects. We use a foot pedal “FX cut” to control this but sometimes forget to switch it back on again.
• The group faders are in pairs but for this application you really want them ganged. A single stereo fader would be even easier.
• It is difficult to see quickly which routing buttons are pressed and which are not.
• The channel fold-back Aux Sends are still live even when the group is off which means the band gets the minister’s solo singing even if the congregation don’t. On a previous desk (StudioMaster) we had Post-fade Aux Sends on the groups. This allowed us to fold-back the whole of the leader’s group to the musicians so they could hear what was being said when needed but on the current desk we have to do individual channels. This is mainly a problem with clip radio mics.

I haven’t investigated if other desks have better facilities.

The last group, 7/8, we use for inputs that are not wanted on the main mix at all. The “send to mix” button is not active on those groups and we use the group output sockets. They are channels that are only required for the recording and other destinations. How this is organised will be the subject of another post.

Visual Liturgy, the package published by the Church of England to make the current version of the prayer book available electronically has been branded as spyware by Norton Anti-Virus. One feels sympathetic towards vicars who had their lifeline software disabled automatically, but perhaps it will teach them not to use Norton. I can’t count the number of times I have had to remove it from systems because it caused problems of one sort or another.

In the computing, telecoms and professional audio/video business the 19″ rack is ubiquitous for mounting equipment. This standard, named after the equipment size, came originally from the cabinets used to house telephone switchgear and has resisted metrication largely due to the dominance of the USA in computing. There is however enough slack in the dimensions to allow a fairly crude conversion to metric units though you do come across modules that are a bit “tight” when mixed with others.

The fundamental dimensions are the overall width to the outside edge of the flanges which is 19″ and a height, edge-to-edge, of a multiple of 1¾”. This height is known as 1 unit or 1U so pieces of equipment are specified as, for example, 3U which is 5¼”. The standard actually says that every item (however large) should be 1/32″ shorter to allow for clearance but this can be ignored unless you are manufacturing them.

The flanges (or ears) have holes for bolting to the rack rails and the horizontal distance between centres is 18 5/16″ though the holes are usually drilled oval which allows quite a bit of sideways movement. For a neat effect you should loosen the screws a little after installation align the units before final tightening. The minimum clearance between the rails and other obstructions should be 17 ¾” though some are a very close fit.

The fixings are most commonly M6 cheese-head bolts (in Europe) and corresponding “cage-nuts” inserted into the 3/8″ square cut-outs in the rails. You do sometimes see drilled and tapped rails but this is usually on proprietary racks used by the bigger computer manufacturers. The rails can either be steel or aluminium and it should be noted that they require different cage-nuts to allow for the metal thickness. The bolts are usually steel and plastic washers can be used to protect the finish. If earth isolation is required then nylon bolts (for light equipment) or plastic flange washers are available, but otherwise it is general practice to earth the rails with a strap.

The hole spacing on the rail is complex. Each U has provision for three holes, though the middle one is rarely used. The spacing to the centres from the top or bottom of the unit is ¼”, 7/8″ and 1½”. This means that they are uneven, some being ½” apart and others 5/8″, making it VERY important that units are correctly located in their proper U positions, not offset by one or two holes. To help with this, many rails have a small notch cut out of the edge of the central square hole in each group to identify it. The cage nuts allow a small amount of vertical movement which may be needed when installing fractionally oversize modules.

The smaller equipment (up to 3U) is usually secured by two bolts on each side. 1U and 2U cases usually use the outer hole positions, 3U cases use the inside ones, being 2¼” apart. Larger modules use four or more bolts in various positions (but again, rarely using the central hole of each U.) It is worth noting that when installing equipment, it is the lower screws that should be inserted first and removed last because it is those that “take the weight” and stop the case from twisting, bending the flanges.

Many racks also have back rails to support heavier equipment; there is no standard depth though 31½” is quite common. Equipment that requires front and back mounting often has movable brackets or is dedicated to one brand of rack. Using runners is quite common for large equipment as it allows maintenance without complete removal, though care should be taken to avoid the rack tipping forward.

When installing equipment it is important to read the ventilation requirements. Although it is possible to butt the units up tight together they may cook, so you may need to leave gaps (with blanking plates for neatness). Fan modules are available for situations where a lot of heat needs to be removed.

This standard leaked for a short while onto the domestic audio market in the late 1970’s when it was fashionable to have the flanges even if you had no rack to install them into. This lingers in domestic circles with “full size” components being 430mm wide which potentially could have flanges attached for rack mounting though many of the cases would not be strong enough. They do, however, fit quite neatly onto rack shelves. Semi-pro gear often has rack mount kit options, though beware that they are often overpriced.

Very topical at the moment as I am trying to get a projector installed at St. Matt’s. Thanks to Dave’s Cartoon Blog for the joke.

I have seen no independent reviews of this software anywhere on the web so I thought it was time that one was done. Note that I come to the product well experienced with using programs of all sorts but never with presentation software, my experience being limited to a brief acquaintance with PowerPoint.

I started with the pre-sales videos available on the maker’s web site. In these a salesman runs through the principle features and it looks very slick. It may be oriented towards the novice computer user but with sufficient power to more advanced things when experience is gained. I then obtained a demonstration copy from a reseller and my view was significantly changed. In fact I used words that Mary says have never been used in our household before. Having composed myself and had a closer look, I still think that it is still more suitable for fertilising roses but at least I can now report what caused that initial feeling.

The impression is that it is written by a games programmer—this may seem rather pejorative but games software is a different discipline to utility software and the requirements and standards are totally different. This impression may be coloured by the “Workspace Launcher,” a glossy red and chrome affair, which may not exist in the full product. The product, when installed, goes into C:\CreativeLifestyles\… not Program Files. This would suggest a very early Windows origin or perhaps even DOS, when all software created its own home directory. In some ways it is fortunate because the default save location for all files (and perhaps for logs and status information) is in the same structure. Program Files is not writeable by unprivileged accounts so it would have failed. A side consequence of this is that all users of the package see the same view, as modified by the previous user—no privacy or independent working—probably not a problem on the projector driver but not so good if anyone can see next Sunday’s sermon slides on the secretary’s computer before it is preached.

Once fired up there is a large but not immediately maximised window much as expected. Maximising the window, which is desirable for the best utilisation of space, disables the Windows task bar—so what if you need to run other software? Best to just stretch the window to nearly full screen. In the standard single palette, single projector view there is a palette area on the left where items for display are chosen, a preview window on the right and a program manager strip showing a pre-prepared slide sequence along the bottom. These are resizeable but, unexpectedly, shrinking one grows the neighbour even to the extent of distorting it to the point of un-usability. For instance the preview window will lose its aspect ratio and the image palette items will change in size rather than there be more (or less) of them. Because of this you can’t be sure that the arrangement in the preview window will be the same as what you will actually see on the projector screen.

The window furniture is all non standard. The title bar and minimise, full screen & close boxes are unrecognisable and there is no menu bar, but in its place there are other buttons along the top which are impossibly cryptic. When it comes to operation then the idiosyncratic features really manifest themselves. In Windows, we are used to the left mouse button being used to select items and the right mouse button to reveal a menu. Not always in this product! In most cases the left button is much more active, causing what it is clicked on to be immediately sent to the preview AND live to the projection screen—no pauses, no “are you sure?” or anything. This is the gamesy aspect of the program, where speed of operation is all important. I can see many red face mistakes being made by newbies where reaction to problems is often to click anywhere to see if something happens. There are a few places where this doesn’t happen, for example clicking a song title opens the item up to reveal the verses, it is clicking the verses which displays them.

The right button is even more quirky. In the palette area a right click sends the item to preview but not to the projector, but in the program manager a menu is displayed. Lastly in the song list, a right click to the title opens a popup for edit—no warning. Looking at areas of the screen in detail the program manager is divided into sequences quite neatly by means of standard looking tabs which work as expected even though they are below the area rather than above. The palette area is tabbed above in a similar way to choose images, movies, songs, and other categories. Each one has sub-categories which are rather harder to navigate using a sort of sideways scroller so, for example, songs can be divided by the user into hymns, liturgical, choruses etc. There is also a (left!) mouse menu to do this by clicking on the category title. Though the song search checks the full text, it doesn’t check all categories, only the one on display so this is less useful that you would imagine.

Using the keyboard arrow keys, up and down selects from some items in the palette area (like verses in an impromptu hymn or Bible passage) and the left and right keys move between prepared slides in the program manager. These are displayed to the projector immediately and the keys are active even if there is another application with focus, even if PM is minimised—so no making sermon notes in a word processor while you are going along, the slides will change as you move the cursor, definitely a manure job!

The popup boxes are another example of variable and non-standard design. Some are entirely navigated like the palette area using the same sort of horizontal scroller mentioned above and some by more familiar windows like tabs. The most obvious thing missing is an OK button. There is a “Close” but it is not clear from that if the changes will take effect. Even then the edits are not saved for the future but are lost when the program is closed with no warning. You need to find the file window for the save option. The popups are modal (you can’t do anything else unless they are closed) and sit on top of all windows, even other applications. Another fertilizer point—try to edit a slide in the program manager (say you spot a spelling mistake) and you will suddenly find it displayed for the world without warning.

Underlying the software the picture is much better. The majority of the data files are XML and those that are not, such as the supplied songs, seem to be in a compatibility mode from an earlier version and save in XML if you alter them. The software seems to be stable and crash proof and runs fast enough to drive video to the projector even on my sluggish AMD1800, though the preview window lurched a bit. I found a few things that didn’t work which I have not managed to track down—PowerPoint display couldn’t find the program, perhaps because I have MS Office and OpenOffice.org installed and the latter is set as the default for .ppt files. I was expecting it not to need either. Printing a service outline produced a page with a row of boxes down the left just containing a red X, I don’t know what is wrong there, I have a fairly standard Canon albeit connected over the network. It is possible it is trying to use the browser to print XML and I have Firefox installed. Audio files displayed a quaver in the program manager but didn’t seem to do anything—do I need a media player of some sort? I have a suspicion that it may be confused by my scroll wheel mouse which is rather non-standard (Trust Ami Pro).

In summary, this is a product where version 6 does truly indicate a package that has been through a long period of growth from the earliest days of ubiquitous personal computers. The internal functions are up to date and the performance can’t be faulted—it is such a shame that the user interface has not grown up with it. I agree that it is not easy with an established user base to change things like this but with suitable compatibility modes for earlier users to migrate, the old fashioned ways do not need to be inflicted on a new generation.

Now having completed an overview of the software that I thought we would be getting, I will have to take a look at some of the competition to see if they are any better—perhaps that is why there are so many of them—over 40 at the last count in what must be a rather limited market.