speaker efficiencey?? Starting point...? 92db??


I recently purchased an spl meter to map out the response on my HT system. The manual for my Yamaha Rx1500(using as pre/pro) says to start at 0 db volume and test each channel from the listening position to 75db. I went through each channel(7.1 sys) and at 0 db i only had to adjust the left front and right surround speakers slightly to hit the 75. All other channels hit 75db at 0db.

Iam guessing that it would be correct to say that my requency response is relatively flat. Forgive my ignorance but i am just starting out in this crazy world of HT. My speakers have an efficiency rating to 92db. what exactly does the efficiency rating mean?>??
dzigon

Showing 1 response by chazzbo

Plato is right.We may be onverge where even HT recievers have room correction to flatenntheings out buit that is now perveiw of #,600 DEQX (great pre/pro),$10K TACT.Some speakers like Infinity have RABOS to take out upper bass "hump" and produce flatter response.But this strays from the question path.
92 db may mean in say 12x14 room you could get into esoteric SET (single ended triode)amps that put out 6 watts as long as you didn't want to blow walls down.But this is another application that you are not into.This efficincy means you will be happy with your 75 watts while another person with 87db speakers would crave more current.As far as what audiokenisis and Matrix were saying I have also heard room of thumb is that-every increase of 3db is like doubling power.But as Laryken points out this is speakers that are 92db with an easy load.I sold B&W for a time and even though 803Nautilus was rated at 90db effcinecy 100 quality watts (an amp stable to say 2 or 1.5 ohms).I thought 200 watts was what folks needed and if in a big room maybe 300 wats so they got CURRENT whose amps may be important than wats.The reason for this even though the speaker was rated at 90db (should be easy to drive right?) it had a nasty impedance dip down into that 2ohm or so range.I do not think that the current delivery from 75 yamaha Watts is at all close to beter made (read more expensive amp) from another company.Even when selling HT I noticed that Harmon Kardon might be rated 65 watts but was louder than a 100 watt reciver (stereo or HT ) from another mid fi brand.Not knocking Yamaha at all they introduced a lot of HT invotaions in HT reciver market and are a good choice at the asking price (which can go to $3K for a top of the line unit),But don't expect it to run like a Krell set up or any other with 200 rms and high curent delivery all around.In sum I don't think if you hear it breaking up where it shoudn't (don't expect the reciver to not distort say the cannon fire in "Last Of The Mohicans".Almost all gear will.Be reasonable).The thing is in Hifi one spec is realtive to another.Things in 70's got so bad the goverment imposed certain standards because companies were coming out with "1000 watt" audio and car gear that would play no louder than one that rated for 60 watts that kept it's ratings to an industry norm and folks complained to FTC.An easy to see example of this is speaker measurement.Measuring speaker you get much better idea on paper of what you will hear if spec is for say low freqency say 60 Hrz. is Plus or minus 2db not plus or minus 6db.Both might be "true" but you'd much rather the bass within the 2 db measurement.The goverment standards were just to keep things from getting into total BS/deceptive advertising but as wuith my comparrison of HK verus Yamaha I sold the goverment standards did not ame evryuthing "absolute" just from getting out of hand.Still you can find those 1000 watt monster amps at Costco for $89.99 so againn by empahsizing one spec while deviating from accepted norm still happens.Not sure why your meter readings trouble you(or if they do) is importanty to you as to paraphrase Duke Ellington "if it sounds good it is good"
Chazzbo