Proposed studio design

Here is a schematic diagram of how I propose we could make a radio station running entirely on free software and commonly owned hardware, if we wanted to. Comments please.
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Updated by markr 2010-07-07

Hey Mark. This is great but it isn’t practical to set things up in this way for a couple of reasons.

First, we don’t own 4 sets of headphones and it wouldn’t really make sense to do it like this when we have directional mic’s which sound great. We’d need to acquire/make a headphone bus or a whole load of headphone preamps which doesn’t make a whole lot of sense in terms of priorities, but if you want to do this go right ahead.

I’m really opposed to using the same box to record and handle the stream as is being used to cue up sound. This really doesn’t make sense in terms of complexity when we have a dedicated external sound card which is both custom built for and specifically bought for the collective to use in just this scenario. Why put an increased load on a poor quality internal sound card with only an unbalanced mini-jack input when we can have 2 big xlr’s directly from the desk and have physical buttons for the master controls and real time, hardware based indications of peak volumes. If you want to hook up the external sound card to the studio computer through jack linked to darkice then great, but as we found last night the club internet connection proved too flaky to handle the stream (we had to fall back to using 3g on my laptop) so we need a backup plan.

We could then use the internal sound card for playing audio through the desk, as long as jack doesn’t let that signal anywhere near the stream through darkice (and we’re prepared for the fact that an ageing P4 with a slow IDE hard disk isn’t going to keep up with the pace of simultaneously recording, encoding, compressing (handled automatically by darkice) reading and playing things without going into meltdown). I think it might be worth you having a look at the computer we have before making many plans for how far you can stretch the processor (I’ve already had several major crashes encoding audio with audacity in the 2 days I’ve been using it). For this reason, I really favour a 2 computer approach so there is failover if one goes tits up, and playing of audio seperated from the recording/streaming.

We have a Behringer hardware compressor (not used last night admittedly as we ran out of time), hardware Alesis ADAT 24 track hard disk recorder, Tascam hardware-based custom built sound module and a decent Spirit sound desk. All of these things are made for exactly this kind of situation and tested over many years. They all have been provided for the good of the collective by numerous individuals. Why are you so set on doing all of this through software and possibly melting the studio?

Anyhow, there’s my tuppence worth, please bear that in mind when you’re making plans for the next show. I’m happy to duck out and do nothing for the next one if you think the whole ting is “heirarchical”, but from talking to the others people really want it to just work, and be streamed in mp3 format so people can listen to it.



Thanks Jim.

On the headphone front, what I was envisioning was that everyone brings their own earphones (from iPod or whatever) and we have them plugged into the headphone outputs on the desk, with suitable splitters & extenders (cheap). In fact it’s probably only the engineer and producer who need to monitor the output in this kind of set-up. I don’t see monitoring through a loudspeaker in the same room as mics to be a sensible option – nobody wants to hear feedback. I wouldn’t produce in such an environment.

As far as the quality of the internal sound card goes, SBlive has a 192dB dynamic range and the EMU10k1 chip is well supported in linux (I’ve been using it myself for years) so I have no concerns whatever about it’s quality & reliability. Audio on debian lenny with ALSA and JACK is solid. The inputs don’t need to be balanced if they’re taking line-level signals from a short cable. As long as the desk has faders and meters, there’s no need to have them on the soundcard too.

Sorry to hear the network flaked out – that’s something we need to get fixed anyhow.

If you’re just using the studio computer to play back audio in windows, you might as well be using an iPod.

You said you’ve had major crashes with the machine running audacity, but this was under windows, yeah? I don’t think you can blame that on the hardware. I’ve been doing multitrack recording on an old 1GHz K7 machine with IDE drives and it worked just fine. With a real OS, of course ;)

I’m set on doing some things in software because of the political and educational benefits of running a free-software radio station. When we’ve talked about this before, you said you wanted to make a linux DAW, which is what I’m proposing now. The various bits of hardware will be useful, but we don’t have to use them just because we have them. That would create more complexity, not less.

I don’t think you should duck out at all, and I don’t think tings are heirarchical- I just think that tings could be more decentralised and more cooperative, that’s all.


An interesting discussion. Much of the software end you seem to be using is quite different from ours but I may be able to give a bit of info on your studio monitoring set up.

The way that we set up our studio is using a ‘mix minus’ which allows everyone in the studio to monitor all content apart from the mic inputs. This means that you can have a monitor speaker and live mics in the same room without the risk of feedback.

The way this works is quite simple (at this stage I should mention that I’m not sure what your mixing desk is like, but this should work on most consoles). Basically run everything through your mixing desk as normal. For the studio monitor take the output from either the AUX 1 or AUX 2 send – not the monitor output. On the controls for each channel there should be a control knob for your AUX channels. For the mix minus to work you need to turn the AUX channel down on all the mic channels and leave it at 0 (or whatever’s comfortable for monitoring) for all non-mic inputs.

Everything will still go through the mixing desk to your stream but this prevents the mics from coming through on to the studio monitor. The producer should always be monitoring the post-compression output, either directly from the streaming computer or from the sound card. In general, you should have one pair of good headphones for the producer to work off.

This set up also calls for two computers to be in use. Generally it is better not to be doing too much with your streaming computer, if even just to avoid the wrong button getting pressed etc. You could just play pre-recorded content off an ipod or something but having a computer gives you more options in terms of formats, last minute changes, playlists and so on.

Hope that is in some way helpful


My thoughts (edited highlights):

The thing the really worked well on Friday was a lot of people having ideas and doing things (on the occasion and before-hand). Everyone sorted themselves out and everything got done, and no one fell off the edge of the mezzanine (if I can call it that).

The technical solution (hard & soft) is interesting to a degree but I don’t want to alienate people who are interested in doing DIY radio with complexities they aren’t interested in.

Obviously there’s things that can be done to pique people’s interest in open source and copy-left (not least a feature, or series of features, on the programme).

But I’m nervous about adhering firmly to favoured solutions, minimum standards or preferred-ways-of-doing-things that either of you (or anyone else) might have in mind, which might impede that actual doing of the thing, or the involvement of people who want to do the thing.

I know, I know, the how-you-do-it is a big part of it, but the listeners and most of the contributors don’t know much about that, and don’t want to learn about it in a big uninvited crash course.

Technically my interest is in learning what works and not being limited to what I already know. I installed the speakers so we could all listen to the music and pre-recorded sgements, and expected to use the auxilliaries, PFL, or groups feature* on the mixer to mute the speakers when the mics were open. Which would require (a) some headphones to be plugged in to the laptop or somewhere close to the broadcast end of things (b) someone sitting near the mixer and aware of that plan to press the right buttons.

(*which exists only in my imagination)

In the (unexpected) absence of both (a) and (b) things worked suprisingly well**. I would have bet real money that it would be a disaster and wouldn’t have installed the speakers if requested to do so for that purpose. Shows what I know.

**Suprisingly well as in: contributors actually compared the facilities and useability favourably with their local tax-payer funded all-mod-cons radio experience.

I don’t see quite as many problems with headphones as JD – there are lo-tech solutions to driving many headphones. But the cable tangle prospects fill me with dread. I do think the Producer(s) should have headphones though, unless they’re in a separate room. And there are no “free” spaces in the club in which to put them. The attic only exists because some people built it.

As regards the former studio computer, I don’t really mind what use it is put to so long as none of the current functionality is lost. We could really do with a better monitor, largely due to the space problems. There was talk of mixing down gigs on computer (rather than using a big desk with enough channels). I don’t know how to do this but I do know that computer has been used for that purpose. Propose we try some mixing soon. Evenings of week commencing 12th? I’m a bit busy until then…

And if we want to put all the software in one box and try streaming that way, can’t we do a dry run the week before the next show? At least then we’ll be testing something proven (but doubtless capable of improvement) with something that only exists as a diagram at present.

Whatever the outcome, it’ll be a useful learning experience.

There’s an issue with our domestic ISP service which someone (not me) will have to deal with. We should (out of politeness) explain to the Phone Coop what our problem is before ditching them, so they can put it in the customer-feedback-analysis-machine before disregarding. Any alternative provider will need to be approved through a members’ meeting.

If we can’t get this fixed before the next show we’ll need to use the G3 thing again anyhow…

Finally: warm words of encouragement:

JD thanks for all the hours you put into this on Friday and Saturday (while I snored beneath my cap).

Mark – I was playing the podcast and went downstairs to make a cup of tea. While the kettle boiled I had radio 4 on. It was one of those magazine programmes with live guests and recorded segments. When I got back to my computer they seemed to be interviewing someone with the same voice as Rachel from Hebden Bridge. It took me a while to recognise that what sounded (in production terms) like the same programme I had on downstairs (Radio 4 – annual budget £51 million) was actually your segment from The Big Green Weekend.

- Obv. some of the other sections sounded like 6music or some lesser sibling. But I think that’s what the contributors were aiming for anyhow…

p.s. wrote all this before seeing Instantwerewolf’s comments – thanks for those.


Thanks, instantwerewolf & protag.

I’m definitely up for doing a set-up and dry-run before the next show, so evenings of 12, 13, 14, 15 and 16th are all good for me. Jim, Jess and Protag (and anyone else who’s interested): if you could let me know which of those dates are good for you, what I’ll do is go in beforehand (participants also welcome) to install another hard drive in the studio computer and get it dual-booting debian. Then we can try to get it working as in the above schematic (maybe with monitoring changes as suggested) and if it fails, no biggy, we just stick with the previous setup for the next broadcast (so there won’t be any last-minute changes) and we can potter about at creating this alternative.

Sorry about the length of that sentence.

Anyhow – Jim, Jess, Protag, anyone else who’s into free audio hacking – which evening/s would suit yous?


mark. In the nicest possible way i get the impression that xat you may be ignoring the advice people are giving you on this. Where you say above that the studio computers basically being used as a big ipod, that’s pretty much right for this scenario, there’s some really good reasons for this to be the case. Where that
computer will really come into it’s own, and what’s really needed right now is for mixing down the many hours of live gig recordings and getting them ready for broadcast, and as a digital workstation for rendering video. For this we really need to get debian, lack, ardour, audacity and kdenlive working realiabjy and well, and for the digital inputs of the card working so we can pull interviews off the minidisk player. Is there any way you could use the energy you have to make that happen as it is really urgently needed. Also, installing that scheduling software you pointed me to would be a massive plus too, as it would make the producers life a lot easier.

in the dedicated hardware we have that i’ve listed above, i forgot to mention by far the most important bit of kit we have upon which the success or otherwise depends, and one we really need to keep working above all else, that’s the 12 or so people who are involved in all this and want their hard work to be listened to by the maximum number of people on a platform that’s reliable. We need to keep that in mind.

during the last show, my dual core laptop with 512mb l2 cache, 3gb of ram running no other services except for handling the stream was still coming up with buffer overruns and was running at full tilt. It takes a lot of resources to transcode audio, package it up and stream it out in real time. If it’s also trying to access the disks amendintibue a jack path then the end result will be instability and an unhappy collective not having their efforts heard. Happy to come to the club to get all the bits i mentioned above up and running as long as i’m not working, but i really do have to keep objecting to the idea of streaming from that machine too.


My impressions is that Mark has proposals that he thinks will work. I think you have the idea it’ll be unreliable.

Things don’t always turn out like you expect. Is there enough time to do some experimenting? We might learn something unexpected.

(I spent years in a band with the {singing} drummer sitting at the front. Local sound engineers were always telling us we couldn’t do that because it wouldn’t work. They had a knowledge-based opinion about likely problems with that scenario. We thought it might just work {like it did the night before} and would get them to try it. Sometimes they would object that there insufficient time for our hare-brained experiments)

I will be at club doing grunty food this Saturday. Weekend after I think I’ll be in London. After that (24th) I’ll be available. Were we going to have a workday? Where’s those minutes!

Sorry I was so undynamic at the mtg. Totally exhausted.


edit – whoops we’re looking at evenings 12th – 16th? – I’ll check my non-existent diary and get back on that


well the point isn’t that it will or won’t work. It may well work, it may not. The point is that it’s putting unnecessary strain on the hard disk, processor and increasing the risk of a blowout for no actual benefit since we have dedicated hardware for all of the software applications that are proposed to run on it. It just doesn’t make sense. From three years doing music technology at uni, the major thing i learned time and time again was never trust a computer for mission critical stuff unless you absolutely cannot do it otherwise. If you have hardware to do the job, use it as 99 times out of a hundred it will do the job perfectly and without having to worry about it. What point are we trying to prove here and at what level of risk for the non techs doing the hard bit who just want things to work. The plan was and still is to set up a linux daw. I never expected that to extend to running the whole radio setup from one single machine, it doesn’t make sense even if it is possible to do.


On your next phone, a carriage return key, perhaps?


Jim: there are risks in any approach, and possible benefits too. For example, one benefit of the scheme I’m proposing is that it reduces the possibilities for failure in old interconnected analogue gear.

I’m certainly not hell-bent on doing everything in software at any cost, but I do want to find out how much we can do, and test it thoroughly before any possibility of using it live. I want to see what all the possibilities are and then look for consensus, for the maximum happiness of all participants.

Anyhow, this evening I’ve installed a 160GB hard-drive and put PureDyne on it. It dual-boots with the old WindowsXP system via GRUB. I’ve not done any formal testing on it yet, but it looks happy, and the OS can see the analogue and digital (including optical) I/O.

Let’s meet next week and see what it can do.


why have you put puredyne on it and not debian or studio64 like we discussed the other night? Is puredyne even capable of video out of the box? It’s a media streaming distro so it’s not going to be suitable for this as we are not going to be streaming from that machine. The main thing we need above all else is something that is running ardour, audacity and kdenlive so we can use it to get material ready for the next show. If we put to the group a choice between something people know works as it did last time, or a risky software solution with no actual benefit, what do you reckon people will go for? In the meantime, we’ve wasted a month when we really need to be mixing down the recordings we have. Great! We need either debian or studio64 on there. Dynabolic is designed for teenagers knocking out their smiths playlists from their bedrooms, not a proper radio show like this.


by the way, the number of times i’ve had old analogue equipment fail on me currently stands at zero. Want to take a guess at how often computers have crashed on me? Particularly when doing intensive audio transcoding. Also, the microphones, headphones, motherboard, sound card, processor, ram and according to her, katies voice are all of proprietary design and so we need to take those things out and bin them if we’re going to have the ‘pure’ studio you’re advocating. I believe the copyright on tin camp and string has elapsed, can we use those instead?


All – the thing I thought was a hadware compressor is just a preamp (it resembles a compressor by the same manufacturer, which I almost bought but didn’t in the end…then forgot what I’d done and generated a false memory of buying that compressor…).

There are other hardware compressors kicking around though.

The only interconnects that worry me (iro hardware failures) are the minijacks which crop up here and there.


you’re sounding a bit crabby :)


Jim: puredyne is debian with a realtime kernel. Like studio64, but happy on 32-bit processors like ours (3GHz hyperthreading P4 with 2GB RAM, yum yum)

It comes with kdenlive, ardour, audacity and jack, all pre-configured and playing nicely with each other. It was made in Huddersfield (partly) and it even has a logo of someone doing a wild-food-walk next to a satellite dish :)

As I said, nothing has been lost – nothing has been done that jeopardises our ability to do everything just like last time, if we want to.

Protag: one thing that I’m totally into doing in analogue is per-channel compression, before the digital stage. Not bothered whether it’s thermionic or solid-state though.

All: next week? tech-soiree? flip-chart paper and schematics that everyone can understand?