Speaker Efficiency

I know there has been a million threads on speakers. But here's another one. I am in the market to buy new floorstanding speakers. I bought some Pioneers on clearence from Circuit City last year and can't stand them. The good news is I can upgrade for up to one year. So now I am ready to do so. The bad news is I have to buy them at Circuit City. I plan on spending around $600. So if anyone is familiar with speakers at CC suggestions would be appreciated. The ones on their website don't seem to be the greatest in my price range.

My question is about speaker efficiency. When looking at the ratings is the higher the number the better number? What is a good efficiency rating? Are these ratings accurate?
Thanks

 

Thanks Steve. That helps a lot. I live in an apartment for now and hate turning up the music too loud to get decent sound.

 

I think Circuit City has several Polk models....might wanna give them a listen.

 

Here is a neat little calculator to play with that will give you a good estimate of what to expect with speaker/amp combo's

SPL Calculator

 

The sensitivity rating lets you know how loud the speaker is with 1 watt of juice coming in, then being measured at 1 meter away (for example, 89db/1W/1M means the speaker's sound pressure level is 89 decibels with one watt power input measured one meter away). Like Steve noted, the higher the first number is (a Klipschorn's sensitivity is approximately 104db/1W/1M) translates into you needing a VERY small amplifier to have a REALLY loud output. A speaker with an 89db/1W/1M rating would need about 16 watts of power input to sound as loud as the Klipschorn would with one watt. The power calculator takes into account room boundaries reinforcing the output (something a Klipschorn takes real advantage of - it's designed to be in a corner where the floor and walls intersect, getting the boundaries to help beef up the output level)...

 

Great calculator. Note that each 3 db increase over the db level at 1 watt will require a doubling of the power amp wattage.

 

The first watt is the most important...

 

What is a currently made high-efficiency speaker other than Klipsch? Also, what would be the lower threshold before a speaker is no longer considered a high-efficiency design?

 

Good question. I would love to know this as well.

 

Just a note the speaker will play 89dB with one watt at "one meter away" not in the entire room its setup in. Well unless the room is a closet LOL !! Just hate to see some poor unsuspecting sole use a 1 watt amp with 89db speakers scratching his head when he can't hardly hear them.

 

Around 89/90db/1W/1M and you start getting into the need for a big amp to drive things properly when you wanna rock out. Around 93/94db/1W/1M would begin getting you into the higher sensitivty speakers... What sort of music do you generally listen to? If you're not a crank 'em up dude a lower sensitivity rated speaker might be fine for your needs (ala listening t chamber music/small jazz combos).

 

Well there is no international body setting definitive standards for what is and what isn't high efficiency, but a lot of people would consider that high efficiency starts around 94db/1W/1M.

 

I didn't want to answer my own question... I was asking just to more get info out there. But my 3.5 watt Bottlehead Paramour 2A3's drive my 97db/watt/1m efficient speakers very nicely. To my knowledge Circuit City doesn't sell much of anything that would be considered high efficiency.

 

I wonder what the combination of today's overly-compressed/limited CDs and effcient speakers are doing to the perpetrator's neighbors all around the world as you read this.

 

We shoulda mentioned that measurements normally take place in an anechoic chamber, not a typical listening environment. This is done so that wall reflections and other acoustic interactions don't take place during measurement...

 

Check out these babies!

http://www.classicaudiorepro.com/

 

This thread has finally cracked my thick head... thanks. Now I know have an idea where my set up is. I have 100 watts driving 91.5 rated speakers. The cool sp calculator says my speakers can deliver almost 102db spl at my position. I listen mostly at 9 o'clock or less on my pre amp. I read between 70 and 80 db on my radio shack spl meter (a recent acquisition along with the Rives CD). Now I know why I have been thinking deep down that it is time to find a set amp in the 25 or 30w range....

 

Very True! Have you ever been in one of those chambers? I did the klipsch tour last year and thise chambers are like the twilight zone of sound.

Craig

 

Efficiency is only one measurement and does not tell the whole story about a speaker. In fact, it tells very little, if anything. In particular, efficiency alone can be a poor predictor of whether a speaker will perform well with low-powered tube amplification. I would hate to see anyone buy speakers based on efficiency rating alone.

Here is a review I posted on another forum of my Harbeth Compact 7s. It includes some info I found about speakers and tubes:

 

I just bought a cheap pair of loudspeakers at CC about a month ago. They are Polk Monitor 70's, rated at 91 db/1w/1m. I really like them for cheap speakers, real neutral. I think I paid about $800 for them, although I can't be sure without checking out the receipt. If you are interested I can PM you a PDF of the owners manual. They are nice floorstanding mini-towers that are 2 1/2 ways that have 1 crossover point that works in 2 different ways. There are 4 6 1/2 " mid-range speakers that are crossovered at 2,500 hz from the tweeter. The cross-over works at -6 db for two of the 6 1/2 " mid-range and at -12 db for the other 2 6 1/2 " speakers. In other words, the 4 drivers are identical, and there is only one cross-over, but 2 of the drivers only kick in at certain volumes. It is a pretty efficient way of extracting the musical content from a low level electrical input without lowering the impedance too much. They do need a lot of room to breath. I placed mine way out into the room, and way away from the side walls, compared to other styles of speakers that I have run in the past. If you have the room, these are nice speakers.