Because if the had a normal sound the bass would get lost in the hum drum and you wouldn't be able to understand what was being said... treble cuts through the ambient noise.
Because they don't hook them up right. Wired the right way, ceiling speakers have the ability to enhance each other. I have heard this after hours in a Pizza Hut roof (non delivery) restaurant. After hours because the company puts rather strict limits on the volume of the Juke box. They relax it a bit after hours.
They also don't use good speakers. Why should they? It's not like they are a prime listening environment. They are doing background music.
Well first Tannoy is a very reputable line and respected in the high end community. I have high regards for their home speakers. I do have to say I have never heard their in ceiling speakers so cant give you a honest opinion on them but my guess is there is there either not installed correctly or to live a room or the equipment driving them is not of high quality.
40 years high end audio video specialist
The cause is most likely the environment itself.
Used where intended, the same speakers should sound quite good.
Could be a number of things depending on how large a space it is. Usually in larger commercial spaces, bass can be improved by increasing the number of speakers available even if the speakers are small a large number of them will increase bass output....Also proper spacing of the speakers also helps to fill the space with sound....Adequate amplifier power is also needed week amplifiers tend to show inadequacy in bass out put first...Long speaker wire runs of 50 feet or more with thin wire or aluminum in stead of copper can effect bass output quite a bit..Also if the polarity is reversed on some of the speakers they will tend to cancel each others bass out instead of enhancing it...So could be a number of factors or a combination of factors leading to inadequate bass
First, how do you know "all the shops" use Tannoy speakers? Lets assume they do, and assume there is (very unlikely) only one model for ceiling installation. Further lets assume (not necessarily the case) that they are infinite baffle (open backed) and have exactly the same amount of free space (also apocryphal) behind them. Further,that each speaker in every instance drew from an adequate 30 watts of source energy. (Probably not.). Lets say the ceilings behind those speakers were un-damped Plaster, and professionally (correctly) installed. Suppose they were all 12 feet overhead. Suppose there were the proper amount of them for the space.covered in the shops. I would then expect that the manager turned down the bass and volume so as not to distract the store patrons ( A choice.) There are other considerations, if the above is not the case, such things as improper installation, too small an amplifier, too big a space for the speakers, will do it too.
cheap speakers, amps that are meant to handle voices,no more is necessary in noisy shops,no need for sound quality of the berlin philhamonic
Ceiling speakers are usually the cheapest thing available in a tin box and using an undersized 70Volt transformer because the shop needs dozens of them to cover the space for the least amount of money. The use of another 70Volt transformer at the amplifiers doesn't help. Odds are that the transformer taps are messed up by incompetent installers. Tannoy has nothing to do with it.