Hi,
A newbie here, both to this forum, and to PA systems! I'm just looking for some advice on which way to go in providing a PA system for voice (no music) that will be suitable for a room around 30mx12mx3m, with the capability of going slightly bigger, if necessary.
I was going to go down the passive route of a mic 4-channel pre-mixer into a power amp (behringer) then out into 4 speakers. But I wondered whether I should use 4 powered speakers and split the pre-amp output to each speaker?
Is that enough information to give me some advice, or do you need more info?
Thanks,
Geoff
A newbie here, both to this forum, and to PA systems! I'm just looking for some advice on which way to go in providing a PA system for voice (no music) that will be suitable for a room around 30mx12mx3m, with the capability of going slightly bigger, if necessary.
I was going to go down the passive route of a mic 4-channel pre-mixer into a power amp (behringer) then out into 4 speakers. But I wondered whether I should use 4 powered speakers and split the pre-amp output to each speaker?
Is that enough information to give me some advice, or do you need more info?
Thanks,
Geoff
Geoff,
What's the application? How loud do you need to go? Are you firing along the short or long dimension of the room?
If it's a one-off, you'll have better results renting something in. If you'll be using it regularly, then used PA equipment is often excellent value for money, so long as it hasn't been pushed hard for extended periods of time.
Chris
What's the application? How loud do you need to go? Are you firing along the short or long dimension of the room?
If it's a one-off, you'll have better results renting something in. If you'll be using it regularly, then used PA equipment is often excellent value for money, so long as it hasn't been pushed hard for extended periods of time.
Chris
For portable applications powered speakers are the way to go these days and for speech only they don't have to be very big... by PA standards anyway. And most of these boxes will have link out connectors so it is easy to daisy chain connect them with XLR signal cables. I have done some outdoor events with 8 boxes spread out around an industrial building covering about 1000ft. So no need for splitters.
Hi Chris and Conanski, thank you for your responses.
The main thrust of my question was whether to go for a passive or active setup. It will be a portable setup in a room of the size mentioned - It is for a conference so mono sound. I was thinking of 4 active speakers with a daisy-chained input from a 4-channel mic mixer. I was looking at 350W active speakers - would this be sufficient?
Do I need to worry about latency when daisy chaining the input signal across the speakers? Are bluetooth transceivers any good for transmitting the input signal or should I stick to hard wiring?
The main thrust of my question was whether to go for a passive or active setup. It will be a portable setup in a room of the size mentioned - It is for a conference so mono sound. I was thinking of 4 active speakers with a daisy-chained input from a 4-channel mic mixer. I was looking at 350W active speakers - would this be sufficient?
Do I need to worry about latency when daisy chaining the input signal across the speakers? Are bluetooth transceivers any good for transmitting the input signal or should I stick to hard wiring?
What speakers are you looking at?
Latency won't be an issue if you use cables, and the speaker deployment to use is the distributed model( all speakers down one side of the room) which will minimize overlap between boxes, BT is too unreliable in crowded RF environments(room full of people with phones). Just last night we had issues with a Shure wireless microphone that had serious dropouts 10ft away from the reciever, this normally wouldn't happen but there were about 500 phones surrounding it and the fix was.. use a wired mic.
Latency won't be an issue if you use cables, and the speaker deployment to use is the distributed model( all speakers down one side of the room) which will minimize overlap between boxes, BT is too unreliable in crowded RF environments(room full of people with phones). Just last night we had issues with a Shure wireless microphone that had serious dropouts 10ft away from the reciever, this normally wouldn't happen but there were about 500 phones surrounding it and the fix was.. use a wired mic.
So 360 Sqm...
4x 350W RMS (not peak) should be sufficient for voice or background music, but for a party add some subs.
Bear in mind cheap speakers (Ibiza sound or the like) give You less sound than known brand ones, despite the wattage or Sensitivity (dB) they claim.
You get what You pay.
I own cheap Behringer stuff. It works well but the construction is not very sturdy.
Behringer makes also powered mixers. No need to carry another flight-case for the amp.
If You select say a 4 Ohm one, There is only one speaker cable because You can connect two 8 Ohm speakers in parallel, or even 4 with an amp capable of 2 Ohm.
If You go the powered speaker route, You have one XLR for signal and have to find outlets for the power cables.
Thank you all for your comments. I apologise ifor the delay in my response.
The powered speakers I was looking at were 4 x Alto TX308 (admittedly these are 350W peak) on stands. These have a convenient XLR link socket to link them together. I need wireless mics so I was looking at the Chord NU4 4-channel mixer for the source? Do I need 350W RMS?
Maaco, I was going to go down the passive route originally but the general consensus here seem to be the active route? The power outlets should not be a problem as the speakers will be along the walls.
Conanski, please forgive my ignorance, what is the 'distributed model'? I was planning to have 2 speakers on each side of the room on the long dimension spaced at thirds. All the speech will be at the 'front' of the long dimension with each speaker spaced at 10m and 20m both facing down the room at approx 45deg angle room?
The powered speakers I was looking at were 4 x Alto TX308 (admittedly these are 350W peak) on stands. These have a convenient XLR link socket to link them together. I need wireless mics so I was looking at the Chord NU4 4-channel mixer for the source? Do I need 350W RMS?
Maaco, I was going to go down the passive route originally but the general consensus here seem to be the active route? The power outlets should not be a problem as the speakers will be along the walls.
Conanski, please forgive my ignorance, what is the 'distributed model'? I was planning to have 2 speakers on each side of the room on the long dimension spaced at thirds. All the speech will be at the 'front' of the long dimension with each speaker spaced at 10m and 20m both facing down the room at approx 45deg angle room?
The altos are surprisingly decent. Cheap unlicensed wireless mics are basically useless every time I have encountered them but this has been at music festivals where there is a lot of wireless activity. Sometimes they work for a bit but inevitably something causes interference and they drop out and a cabled solution has to be used. I would recommend paying for licensed bands for your venue and using the pro gear, or you can do it on a per event basis for about £30.
I'd recommend active speakers too, with just one amp if it goes down you've had it. Not so with 3 other active speakers. As per above the Alto speakers are surprisingly decent. I've only heard the 312 and it created quite a lot of noise and of a reasonable balance, especially considering the price. The 308, the compact size, price, and your intended use they should do the job well i think. If you have a bigger budget I'd go for Yamaha actives as they sound much better but are a lot more money.
so what are you equalizing with?
quick search on that Chord NU4, other that level mix there's no provision for EQ of the individual mic's so you have no means of countering feedback...and with four open mics potentially hand held feedback can happen fast!
in keeping system cost down i would at least find a decent quality 31 band EQ for both feedback control and a crude means of tone control.
powered speakers are the way to go.
as to whether a distributed or point source or other approach is used for speaker deployment i would let venue layout and acoustics dictate that.
quick search on that Chord NU4, other that level mix there's no provision for EQ of the individual mic's so you have no means of countering feedback...and with four open mics potentially hand held feedback can happen fast!
in keeping system cost down i would at least find a decent quality 31 band EQ for both feedback control and a crude means of tone control.
powered speakers are the way to go.
as to whether a distributed or point source or other approach is used for speaker deployment i would let venue layout and acoustics dictate that.
I am indebted to you all for your great advice -thank you!
I must stress that I am an amateur at this and am simply looking for a decent portable PA system for use at a (annual) conference (no music) with 3 speaking personnel, who will all be speaking from one end of a 30m x 12m room (3m high). I have a budget of around 1,000 UKP (~1,100 Euro, ~1,200 USD), give or take.
Turk 182, we only need 3 of the 4 channels and it is unlikely that all 3 headset or lavalier mics will be operating at the same time - at most two - and we were planning to turning down the mic levels at the mixer when not speaking. We always ask any attendees to switch off mobile devices to reduce interference. Do I still need an EQ? If so, can you recommend one within my budget?
I will be making my purchase by the end of the month, so please keep the recommendations coming until then.
Many thanks, Geoff
I must stress that I am an amateur at this and am simply looking for a decent portable PA system for use at a (annual) conference (no music) with 3 speaking personnel, who will all be speaking from one end of a 30m x 12m room (3m high). I have a budget of around 1,000 UKP (~1,100 Euro, ~1,200 USD), give or take.
Turk 182, we only need 3 of the 4 channels and it is unlikely that all 3 headset or lavalier mics will be operating at the same time - at most two - and we were planning to turning down the mic levels at the mixer when not speaking. We always ask any attendees to switch off mobile devices to reduce interference. Do I still need an EQ? If so, can you recommend one within my budget?
I will be making my purchase by the end of the month, so please keep the recommendations coming until then.
Many thanks, Geoff
imho headsets will give the most consistent predictable results, lapel and pin on lav's can be affected by clothing noise or suffer from high frequency loss because of clothing type.
as to EQ's stereo 31 band of the pro variety like Klark Dbx Yamaha (and i prefer older eq's with 10 cm faders) can be had fairly reasonably on the used market.
as to share my thinking here, a 31 band by virtue of the number of bands are narrower Q filters allowing notching feedback while leaving more of the program material intact.
in shopping for powered speaker researching features and the DSP they have may potentially alleviate the need for an EQ, most have presets along with things like additional PEQ settings that could used as notch filters for feed back control.
as to EQ's stereo 31 band of the pro variety like Klark Dbx Yamaha (and i prefer older eq's with 10 cm faders) can be had fairly reasonably on the used market.
as to share my thinking here, a 31 band by virtue of the number of bands are narrower Q filters allowing notching feedback while leaving more of the program material intact.
in shopping for powered speaker researching features and the DSP they have may potentially alleviate the need for an EQ, most have presets along with things like additional PEQ settings that could used as notch filters for feed back control.
Hi,
Any complete system you can afford for that budget will not be of a very high quality.
Like Chris said in the very first reply, if you're only needing it once a year it would be far better to rent decent quality kit.
Yes, it will cost more over several years, but every time you use it you'll have better results.
Plus, someone else takes care of storing it & maintaining it for you the other 51 weeks of the year.
Re feedback control, if you rent you'll get a regular sound desk with the package, that could be anything from a small analogue desk like a Soundcraft EPM series with 3 band tone control per channel, giving a very basic level of adjustment, on up to a digital desk with 4 band fully parametric EQ on each channel plus the same again on the outputs and graphic EQ's available to insert on subgroups or outputs as needed.
HTH,
David.
A distributed model has the speakers "distributed" around the room and operated at relatively low output levels so that there is a minimum of overlap in coverage between them. If I understand your description above you are planning to use that type of setup more or less.
As for the other equipment required, if you were to do this to the highest standard about $10k in equipment would be used. That would include specialized hard wired conference mics, high quality powered speakers, and a digital mixing console that includes a feature specifically designed for conference audio called auto mixing. This feature does what you would have to do manually with an analog desk... lower the levels of all inactive mics and give priority to one, this all happens automatically and the mixer can react faster than a human so the end result is better. This mixer will also have all the processing to maximize sound quality and prevent feedback which includes gates and parametric EQ on every input and in many cases an automatic feedback supression system.
The microphones used are important, a typical hand held needs to have the capsule right on the chin to maximize gain before feedback, if the mic sits in a stand 1 foot away from the speaker you will REALLY struggle to get any signal level out of them and squeeling feedback will be a big problem.
The bare minimum needed in an analog mixer is somethhing with a 3-band EQ and highpass filter on each input, and if you add a graphic EQ for feedback it should go on an insert to that channel which means you need 1 EQ channel per mic, and they have to be a good quality 31band with a visual feedback indication system like the PV Q231F or Art HQ231. Without something like this an inexperienced operator will never be able to accurately identify what frequency the feedback is happening at quick enough for it to be of any help, so a regular 31band EQ is of little use here.
The takeaway form this is this type of event can be harder than it would seem, and there is a BIG difference in capabilities between a shoe string budget bare minimum system and a state of the art modern system. The modern system will also be much easier to move and deploy... it could literally be 4 speakers n stands, the mixer which could be as small as a rack mount stage box type, a handfull of mics, and a bunch of cables to patch it all together. You can probably rent this for about $300.... depends on pricing in your area, and once setup it will be easy to operate with the computer(digital mixer) doing most of the work. The budget setup will be more equipment to move and you will have your hands full for the duration of the event, there may not be a lot of mic issues if you get the right type but you still have to pay attention and ride the faders the whole time.