speaker ratings? 83db vs 96db

[STARSCREAM]

Could someone please explain to me how huge of a difference there would be with a speaker that is rated at 83db and the other is 96db ? How big a difference is this in real world listening for movies.

[Steve]

That's a pretty significant difference in efficiency. The 96dB speaker will take far less power to drive up to high volumes. What speakers do those specs come from?

[STARSCREAM]

The 83db comes from the Onkyo ht-s9100THX HTIB system for it's fronts, the surrounds are 81db.

The 96db comes from the Klipsch Icon XF-48 towers. They have built in amp.

[mastertang]

The above post is correct. Most high end type speakers are near 100. In the end, your ears are the only judge that matters.

[tootall82103]

Originally Posted by mastertang

The above post is correct. Most high end type speakers are near 100. In the end, your ears are the only judge that matters.

When you say near 100, do you mean give or take about 10?

[SammyG]

Originally Posted by mastertang

The above post is correct. Most high end type speakers are near 100. In the end, your ears are the only judge that matters.

I respectfully disagree, planar speakers, which are very high end do not have a high sensitivity. You will need a lot of power to get full potential from them.

[kingofgrills]

A speaker's efficiency has no real correlation with the sound quality it produces. Ribbons, electrostatics, and planar speakers generally have lower efficiency levels than many speakers, yet they can offer fantastic sound quality.

[Steve]

Originally Posted by STARSCREAM

The 83db comes from the Onkyo ht-s9100THX HTIB system for it's fronts, the surrounds are 81db.

The 96db comes from the Klipsch Icon XF-48 towers. They have built in amp.

That's funny. In the back of my head I was thinking the exact same brands.

Ultimately no speaker will sound better than another just because it's more sensitive/efficient. It'll take less power to drive, but that's all.

[richteer]

Originally Posted by STARSCREAM

Could someone please explain to me how huge of a difference there would be with a speaker that is rated at 83db and the other is 96db ? How big a difference is this in real world listening for movies.

For every 3db increase in sensitivity, double the volume. So, for a given power input, a speaker with a sensitivity of 96db will be significantly louder than one with a sensitivity of 83db. But kingofgrills said, a speaker's sensitivity has got absolutely nothing to do with how good it is.

[Big Daddy]

Sensitivity is calculated by measuring the sound pressure level at one meter, with 1 watt of input power, at 1KHz (1,000Hz). This may be important because it requires twice the power to increase the volume of a speaker by 3dB. Horn loaded enclosures such as Klipsch are used to manufacture very sensitive loudspeakers. A funnel is placed in front of the speaker, acting as an acoustic amplifier, thus improving the efficiency and the directivity of the speaker. Full-range drivers are also very efficient. However, sensitive speakers do not necessarily produce better sound.

Many companies use voltage to measure sensitivity. Here again, 2.83 volts are inputted and measured at 1 meter.

Note that from Ohm's Law, P = V^2 / R. Therefore, 2.83 volts into an 8 ohm load is equal to 1 watt,
P = (2.83)^2 / 8 = 1 Watt.

A speaker's efficiency in transforming power into sound is to a certain extend determined by the impedance of a speaker, 2.83 volts becomes 1.5 watts at 6 ohms and 2 watts at 4 ohms, a 3dB increase.

It requires twice the power to increase the volume of a speaker by 3dB. Let's assume we want to achieve 110dB level of sound. Speaker 1 has a sensitivity of 83dB and requires 512 watts. Speaker 2 has a sensitivity of 96dB and requires less than 32 watts.

Speaker1.jpg Speaker2.jpg

[STARSCREAM]

Thanks guys, and once again BIG DADDY you are the man!
So putting the numbers aside, what effect does it really have on real world listening? I sit about 12-15 ft. away from screen and front speakers. When watching a blu-ray is the 83db rating going to really affect anything? I guess over some research I've been doing it would greatly hamper some of the blu-ray's that have dynamic peaks at or near reference level and would/could cause clipping or distortion.

[Big Daddy]

Originally Posted by STARSCREAM

Thanks guys, and once again BIG DADDY you are the man!
So putting the numbers aside, what effect does it really have on real world listening? I sit about 12-15 ft. away from screen and front speakers. When watching a blu-ray is the 83db rating going to really affect anything? I guess over some research I've been doing it would greatly hamper some of the blu-ray's that have dynamic peaks at or near reference level and would/could cause clipping or distortion.

Don't associate sensitivity with quality. I am assuming two sets of speakers have exactly the same quality except for sensitivity. The more efficient speakers are going to play louder and have more dynamics with a lot less power. This is very important if you have a low powered receiver or a tube amplifier. In home theater, people tend to associate louder with being better, particularly for movies with lots of special effects.

The other factor is power rating of the speakers. For example, I built a couple of DIY speakers with full-range drivers. See post #116 in the DIY Speaker Building thread. Their sensitivity rating is over 95dB and the power rating of the drivers is less than 50 watts. Don't let that mislead you and conclude that they are not as powerful as speakers that are rated 200 watts. With such a high sensitivity, you do not need a lot of power tolerance as with 10 to 20 watts, you can achieve pretty loud volumes in your room. With more than 50 watts, the ceiling will fall on your head.

[Beerserker]

Hey Starscream. I'll just add that, at your seating distance you can expect to hear a max of 98db from those onkyo fronts. In scenes using the surrounds for sonic reinforcement it will be higher, but that is the max you can expect in this situation. If this is enough dynamic range for you, I don't know. I appears as if the reviewers are impressed with how it sounds for a HTIB though. I didn't really look into that Klipsch, however I'm sure it's loud enough for Helen Keller, Klipsch always is.

[Gremal]

Originally Posted by Big Daddy

The more efficient speakers are going to play louder and have more dynamics with a lot less power. This is very important if you have a low powered receiver or a tube amplifier.

Yep, which is why single ended triode amps are best paired with horns. That's probably the approach I'd use if I had room for separate audio and HT systems.

[JBL4645]

This little easy to use Crown power required for speakers say at given 85db is plenty loud enough.

http://www.crownaudio.com/apps_htm/d...ct-pwr-req.htm

I use this handy online measurement calculator after measuring with tape measure
http://www.onlineconversion.com/length_common.htm

For the distance at 7 feet I need only 4 watts with plenty on tap for the LCR LF and HF.

Surrounds 3 watts

Sub I need very little according to it LOL 0 watts LOL that’s plenty of headroom!

[STARSCREAM]

Originally Posted by JBL4645

This little easy to use Crown power required for speakers say at given 85db is plenty loud enough.

http://www.crownaudio.com/apps_htm/d...ct-pwr-req.htm

I use this handy online measurement calculator after measuring with tape measure
http://www.onlineconversion.com/length_common.htm

For the distance at 7 feet I need only 4 watts with plenty on tap for the LCR LF and HF.

Surrounds 3 watts

Sub I need very little according to it LOL 0 watts LOL that’s plenty of headroom!

Thanks for that. It said I'd hit 98db. Seems like plenty to me? Aren't you supposed to calibrate to 85db per channel anyways, so that leaves me 13db headroom? Does it matter if an audio track has dynamic peaks over 100 or so, what would it do just not let me hear that frequency or would I hear distortion?

[Big Daddy]

Originally Posted by STARSCREAM

Thanks for that. It said I'd hit 98db. Seems like plenty to me? Aren't you supposed to calibrate to 85db per channel anyways, so that leaves me 13db headroom? Does it matter if an audio track has dynamic peaks over 100 or so, what would it do just not let me hear that frequency or would I hear distortion?

The 75dB or 85dB that you use to calibrate your audio indicates the average dialog level. The peak level is set 20dB higher at 105db and the LFE peak level is set +10dB higher to a maximum of 115dB. There is an explanation of Reference Level in the first section of Understanding Dialog Normalization thread.

[STARSCREAM]

Originally Posted by Big Daddy

The 75dB or 85dB that you use to calibrate your audio indicates the average dialog level. The peak level is set 20dB higher at 105db and the LFE peak level is set +10dB higher to a maximum of 115dB. There is an explanation of Reference Level in the first section of Understanding Dialog Normalization thread.

Great stuff there Big Daddy, thanks. I'm still confused though on if the 83db fronts and 81db surrounds would get loud enough. I'm assuming they would. I don't want ear damaging levels, just want to be able to play the tracks loud. The receiver is 130 watts per channel, don't know the real world watts though on 7 channels driven, I'd assume probably significantly lower but would probably be enough to let the speakers play loud since they would need all the watts they can get with that low sensitivity rating. Thanks for taking the time to answer my questions, this theater stuff gets confusing the more and more you read and study it. I've never really paid attention to sensitivity ratings before.

[Big Daddy]

Originally Posted by STARSCREAM

Great stuff there Big Daddy, thanks. I'm still confused though on if the 83db fronts and 81db surrounds would get loud enough. I'm assuming they would. I don't want ear damaging levels, just want to be able to play the tracks loud. The receiver is 130 watts per channel, don't know the real world watts though on 7 channels driven, I'd assume probably significantly lower but would probably be enough to let the speakers play loud since they would need all the watts they can get with that low sensitivity rating. Thanks for taking the time to answer my questions, this theater stuff gets confusing the more and more you read and study it. I've never really paid attention to sensitivity ratings before.

Normally, you calibrate all your speakers to around 75dB or 80dB. If you have an SPL meter, it will help to actually see the results. Your receiver is more than adequate. For most movies, you should be ok with great results. In some movies, the center channel may be a bit low. You can boost the center channel gain in the receiver by a few db's. It is also ok to increase the bass level by a couple of dB's, but don't overdo it.

[jomari]

in an average home, id have to mention that a good AVR set with at least 80w per channel (clean) is more than sufficient to drive the general amount of speakers in the market right now. of course, the higher the sensitivity, the easier the AVR would be able to drive them.