In the masjid sound system or for that matter any PA system, speakers play the most important role. They can make or break the system. Depending on how big the masjid is, number of people and masjid design you can choose from a variety of speakers. This is once again an area which every time we try to limit our list, it keeps growing.
A general rules of thumb is ... bigger the masjid, bigger the speakers in terms of wattage. You can install fewer larger speakers (12" cone is the maximum) or get more smaller speakers with like 6" / 8" / 10" cone. Tweeter size and quality is more important. Any good tweeter between 3/4" to 1.5" should be good. Apart from the size it is how the speakers sound is of upmost importance. We have compared pretty much all commonly used speaker models from Electro Voice, Makie, Bose, QSC, JBL, Samson, Proel, Yamaha, Behringer, Community, Tannoy etc. It is all about sound and we have our favorites that we use in installations. They range from $100 a pair to $10,000 per piece. So depending on how big your place is and how much you wish to spend on the sound system the choice differs.
How many speakers do we need in our Masjid ... ?
Spoken word indoor needs less than 1 watt per person. Acoustic instruments and solo performers need about 3 watts per person. Tilawat lies somewhere in between the above two. It is always good to get a little more and turn the levels down rather than have something less running at full throttle. We usually go for 3 watts per person because we stand very close to each other in tight ranks for salaat. We need less wattage of power per person when we are sitting comfortably spaced on chairs. Remember human body absorbs sound and more bodies that are squashed together the more sound will be absorbed. Most of the time wall or surface mount speakers are of better quality than ceiling speakers. It would be a good idea to install wall or surface mount speakers at least 8 to 10 feet high to shoot sound over peoples head and minimize high frequency absorption by human body.
Reference point ...
The room noise level of a typical masjid with the a/c and other equipment running is usually around 40 to 45 decibels. We need to raise the speech at least 25 decibels above the room noise level for very good intelligibility. We would recommend 70 to 75 decibels as a good starter sound pressure level (SPL) in a masjid. Every masjid runs their PA system at a specific SPL which varies quite a bit from masjid to masjid. You need to have enough speaker and amplifier power / wattage to raise the human voice to this level. ..... Just for reference, a movie theater is calibrated to be at 85 decibels.
Follow the steps below to come up with your speaker wattage for your masjid.
Step 1 ...
Maximum number of people who will ever be in the masjid at a given time. For example eid prayers ... let us say 500.
Step 2 ...
Speaker wattage power we need is 500 x 3 watts = 1500 watts of speaker wattage at speaker RMS or continuous power.
Step 3 ...
Now how many speakers should I get. Well you can get two speakers whose RMS rating is 750 watts or ten speakers that have an RMS rating of 150 watts or any other combination. The idea is to get as many speakers or as few speakers that will result in even sound in the masjid. Too many and very small speakers will effect sound quality. Usually bigger the speaker the better its sound quality and frequency response.
Step 4 ...
Get the amplifier(s) that will cleanly drive 1500 watts of speaker power. A good rule of thumb will be twice that of aggregate speaker wattage i.e. 3000 watts in our example.
All the numbers used here are guidelines and estimates. A lot depends on the building shape, size, material used and of course how loud the Imam is and his microphone technique. For outdoor applications, double up the numbers. Speakers on minarets is a completely different ball game.
IMPORTANT: Please refer to 8 Ohms or 70/100 Volt Sys for more details on speaker wattage and impedance information.
We recommend that you stay away from Bose, Samson and Behringer speakers.
In certain situations where the Masjid is huge with high sealing and a large dome in the center with too much echo or reverberation then the speaker choice is limited. You have to go with speaker arrays. The idea is to prevent the sound from reaching that part of the masjid that is causing the reverberations and echos the most. And that is usually the upper area, roof and especially the dome. This long rectangular shaped speaker is made up many smaller speakers (anywhere from 3 to 25) stacked together in a vertical line.
The array speakers if installed correctly will not throw sound more than few feet above the ground hence preventing it from reaching higher areas near the ceiling. The horizontal sound spread on these speakers is usually 100-180 degrees and the vertical spread is around 0-25 degrees. In a nutshell these column speakers have high direction control. Some commonly used brands / models are ...
Bose Panaray MA12
Duran Audio AXYS Intellivox speakers (now part of JBL)
Tannoy i7 / i9 and QFlex series
JBL CBT Series
Renkus-Heinz IC Live / Iconyx
K-Array Kobra KK50
Meyer Sound CAL 64
EAW DSA 250i
RCF VSA 2050
Intellivox speakers in the Grand Mosque in Abu Dhabi ....
favorite regular installation speakers (not array speakers) are as follows ...
Small Masjid ...
Yamaha ns-aw350 indoor / outdoor speakers (We call them poor man's speakers)
Tannoy Di5DC / Electro Voice Evid 3.2
Medium Size Masjid ...
Tannoy Di6DC, Electro Voice Evid 4.2 Series, Proel Xenia series etc
Large Masjid ...
Tannoy Di6DC / Di8DC , Electro Voice Evid Series etc
Huge Masjid ...
Electro Voice sx300e, Evid 6.2, Tannoy i9 etc.
There are unlimited speakers to choose from but after experimenting several dozen models from various manufacturers we use specific brands and are also manufacturing our own speakers in US. Surprisingly Bose did not make it into our list even though they are the ones used in Haram.
Horizontal and vertical spread of sound also needs to be accounted for when selecting the speakers. Speakers with sensitivity (loudness) rated in the upper 90's are the best. If we are doing a 70 volt system we do not use ceiling speakers instead use wall mounted speakers.
There are concepts like bi-amping speakers, using powered speakers, crossovers and minaret speakers which we are skipping because of their limited use in Masajid at least in north America. All you need is a very clear sounding speakers which are loud enough, have good crossover and are reliable enough for years of service. If someone wants to use the biggest available minaret speakers then go for Community RSH462 speaker. This big boy can throw sound to a mile.
The idea of a PA system is to raise the voice 10 to 20 db over room noise to be able to hear everything without any effort. Even sound between 70 to 85 db is sufficient in most Masajid. All measurements should be done when the Masjid is full to its capacity. Human body and heavy clothing absorb lot of sound. Please remember we do not need sub woofers for speech or tilawat. Human voice has almost nothing between 0 and 150 hertz which is typically called bass range for which sub woofers are used. However if you were to cut this frequency range, you will clearly hear its effect on other frequency bands. Use your ears when making this call.
QSC K12 Powered Speaker