Question
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Followup To
Question -
Ok, I have a problem and I haven't been able to figure it out after hours of work.
Our church has an older audio system, with a 20W amp, and uses two mikes, while broadcasting to a few older speakers as well. Just recently, our amp (it is about 20 years old) started cutting out on on of the mike inputs. We decided to upgrade to a newer amp, and decided to get a larger one for future expansion options as well.
We purchased a new 40W amp, but when we hooked it all up, we could not get near enough volume to fill our 48' X 28' room. We asked the "specialist" at our local car audio store and he recommended going up to a 100W amp, and that should solve all of our problems. We now got decent volume when we put the mike right up close to our mouths, but our need is to have decent volume when the mike is 1 to 3 feet away from our mouths. This works just fine with our older 20W amp.
If there is a simple fix for this, could you help us out?
If not, could you recommend a setup that would work for our needs, which would be using a mike 1 to 3 feet away while still broadcasting decent to fairly loud volume to a 48' X 28' room? We are on a fairly tight budget, with our maximum being $300 CAN. If possible, we would like room for future expansion.
Thanks,
Jacob Marttinen
Answer -
Without knowing more of the exact equipment (make and model) I cannot give an intelligent reply. I can guess that the microphones you are using are low output and the old amp had high gain preamps for them. The microphones you use and the type of preamps will have a tremenduous effect on what the results will be.
You will never get a good sound reproduction with the microphone 3 feet away from the speakers mouth (without high tech assist).
48 by 28 is not a big room, but the acoustics of the walls, floor, ceiling will have big effect on the final result.
FOR: Budget sound systems the best is Radio Shack. They have a 40 w unit for about $100 that will do your job nicely. They have an upgrade model that is 250W for around $250. Both have sufficient inputs for almost any standard microphones.
NEXT: You should look at the microphones you are using; they may not be current stuff. Let me know the make and model and I can advise you what to do with them.
Next time, stay away from a car audio store for advice on PA sound! That is like going to a brain surgeon when your foot hurts! I am sure they are competent in auto sound, but hall public address requirements are totally different!
Please let me know further as you go along and I will give you sound (no pun intended) advice.
Cleggsan
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Ok, the amp we have bought is a 100 W one from The Source (which is Radio Shack in Canada, they just changed the name recently), which was right between the two you recommended.
I was not able to find any brand name or model number or anything on the mikes. I talked with some other members and they said just to replace the mikes. They also said to get all new speakers, as the one we have now is older (an 8"), and we do not know the power of it. We have had to glue the (paper) cone a number of times, as it has ripped.
The 48' X 28' room is about 15' to 20' high, and it has terrible acoustics. All we need is a speaker to have anyone, anywhere in the room able to hear. The speaker we have now is sufficient with the older amp, but we would like a bit more power/volume. Any recommendations, for volume, speaker size, etc.?
And mikewise, we need at least two (three would be nice) mikes, that aren't too expensive. Which should we get? Would we also need preamps? If so, which of these should we get?
If you need anymore info, like model numbers, etc., I will try to get it if you ask.
Thanks Again,
Jacob Marttinen
AnswerPower and gain are two different matters; you can have all the power in the world but it won't be very loud if the system gain is low. The gain in most PA situations is a function of having the right microphones for the inputs on the amp.
Either of the Amps I recommended from Radio Shack (or the Canadian stores that carry them) would be adequate for your system. They have all the inputs you will need.
The microphones should be cardiods for best gain characteristics. They should be balanced line outputs so they can connect to the xlr inputs on the back of the amp/mixer. (The lower cost one has only phone inputs, not xlr. I therefore recommend the bigger unit, which has more flexibility).
Speakers can be either stand alone - which you can move around if your space is multi-purpose, or you can permanently install them on the walls or ceiling. A PA engineer should be consulted on such matters. The decision will be based on the space, acoustics, your location for using the microphones (to avoid feedback problems) and such.
For stand alone, which I like because they can be located for optimum performance, you would do well with the Radio Shack or equivelants. Please go to radioshack.com and just search their web pages for PA speakers.
Microphones: Again, Radio Shack is about the only place to obtain low cost, but reasonably good quality microphones. Go to their webs and check; they have a unidirectional, a cardiod and super cardiod all under $50 each. Normally, a good PA mike costs in the $300 range, but these are a good compromise where budget is important.
Hoping this will help guide you along the way.
Cleggsan
