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Matthew Fleet Unregistered guest | What exactly is meant when referring to 'speaker sensitivity'? My understanding is: sensitive speakers are ones that sound loud even with low wattage amps. In other words, one doesn't have to turn the volume dial up too much to get decent volume response in the speakers. Is this basically what is meant? |
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Silver Member Username: Stealth_cDublin, CA USA Post Number: 168 Registered: Jan-05 | Speaker sensitivity will generally be given as a SPL measurement taken at 1 meter on axis with a 2.83 volt input (1 watt @ 8 ohms). The higher the SPL, the more sensitive/efficient the speaker is generally speaking. There are however plenty of factors that can affect this figure which manufacturers may not wish to cite in their specs. |
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Silver Member Username: PetergalbraithRimouski, Quebec Canada Post Number: 372 Registered: Feb-04 | Matthew, By the way, SPL = Sound pressure level. Yes, the sensitivity figure will tell you how loud a speaker can get given a specified input. It varies greatly from 80 dB at 1W and 1m to 104 dB at 1W and 1m. That 24 dB difference means that the more efficient speaker requires 1/256 of the power needed by the less efficient one to produce the same loudness (a factor of 2 for every 3 dB). So the first one all out at 100W is as loud as the other driven with 0.4W. Note that these are extreme numbers on both sides. |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 3504 Registered: May-04 | Things that can affect sensitivity: https://www.ecoustics.com/electronics/forum/home-audio/130011.html |
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Silver Member Username: PetergalbraithRimouski, Quebec Canada Post Number: 375 Registered: Feb-04 | I don't know... I agree that speaker impedance matters, but not all that talk about power loss by the crossover. The rated sensitivity takes this loss into account (higher loss leads to lower sensitivity). Similarly, 92 dB is 92 dB acoustic output whether it is given by 1n 8 inch long-throw driver or a 15-inch driver. A 2 dB difference might not matter so much, but anybody can tell a 10 dB difference, never mind 24 dB! |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 3508 Registered: May-04 | Peter, it sounds like you need to go back through all the information I put on that thread to better comprehend the situation. Don't misunderstand what I said to mean every speaker that is rated at the same efficiency as another speaker will play at drastically different volumes. That was not and is not my position. But as the number of issues mount that can affect the percieved volume level, it is easy (I think) to understand why two speakers rated at the same spec on paper might not sound the same in a room connected to the same amplifier. This looks again to be a situation where you want to put qualifiers on the conditions of the measurements and then say I was incorrect. Take the statement at face value and judge whether two speakers rated at 89dB/W/m (with no other information provided) might not play at equal volumes. Play out in your mind all the things that could affect the percieved volume from those two speakers. That was my point. Until you know much more information about the speaker and the system it will be placed in, the specs are just little swiggles on a piece of paper. If you don't have the knowledge to put together what those additional specs CAN IMPLY, you might as well be reading a foreign language. It's like a doctor diagnosing lung cancer when the patient only says they have a cough. Even with every spec you can find laying in front of you, there are still qualities of a speaker's reproduction that cannot be quantified by numbers. |
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Matthew Fleet Unregistered guest | I think I agree with Jan's very last sentence in his last post. But specs. do help and understanding the SPL rating has helped me. Generally I now know what that number means and what it would seem to indicate with regards to 'how loud a speaker will sound with little or no effort'. (ie. little volume). Thanks guys. |
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Matthew Fleet Unregistered guest | Here's a question: What are some of the factors that could lead to 'volume loss' between two speakers, with the same specs. and sensitivity levels, and run through the same amp? (Cables, clips, hookup - would these factor in?) |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 3514 Registered: May-04 | Mathew - Read the thread I linked to above. It goes through the concepts of what speaker specifications might tell you and might not tell you. Beyond just the rated test bench power the amplifier the speakers are working with can affect volume level for reasons I discuss in that thread. Unless the resistance is abnormally high on a speaker cable (very thin gauge and very long lengths), the items you mention should not be factors. |
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Bronze Member Username: AudioholicPost Number: 39 Registered: Apr-05 | Matthew, yes sensitivity specs are important...to a degree. Is volume your only or main concern? |