speaker sensitivity

[padego]

Hello everyone,
I'm new here and this is my firsy post, is there someone out there who can explain, in as simple of terms possible, what makes, say, one speaker 86dbs and another 95dbs. Is it the speaker design, the crossover?
Judjing by the amount of impressive expertise here I'm fairly certain this is a stupid question, but as someone who just got into a low power tube amp, (10 watts) thats in a large loft style listening room I'm searching for the right type of speaker to fit and a little understanding goes a long way to a final decision...
Many thanks!

[joensd]

Hi,
I think Nelson Pass article about sensitive fullrange drivers and current source amps would make a nice reading for a start and also already give you a nice choice of possible drivers/enclosure for your application :
http://www.passdiy.com/pdf/cs-amps-speakers.pdf
(link to 2.5MB pdf-file)

greets

[Hrappur]

10 w could be considered a high-powerd amp here! The fullrange speakers are usualy very eficient and only need about 5 w, thats for a 95 db/w/m;

the rule is that 1 watt of power produces 95 db, mesured at 1 meter from a speaker thats rated as 95 db.
So the higher the dB value the more sensetive the speaker, sensetivety is a combination of enclosure and the speaker it self but the crossover can only affect sensitivety in a negative manner (as a resistor)
I wouldnt recomend a speaker bellow 90 db sensitivity for your amp and the higher the db value the better in most cases

[Gregm]

Just to add to the above, your nominal 10W will afford you an extra nominal 10db spl -- before clipping.

So, a 95db /1m spkr can rise as far as 105 db (at 1m of course). That's pretty loud considering many of us listen at an average of 75-80db spl (at listening position of course).

[padego]

Thanks guys!
Your info has been greatly appreciated and has cleared up a lot of the mystery for me...

[adason]

i find this article highly informative about the speaker sensitivity vs amp power issue
http://www.colomar.com/Shavano/spl.html