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Speaker Understanding <- Clever People Post In Here (pg. 2)
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| Project T |
| what i would really like to know is that i have 400rms output speakers that supposedly go up to -96 Db or whatever :confused: and that the bass climbs no louder after 3/4 of the volume is reached. and why people with much smaller bass cones than me get much more sound even though my bass cone is about 8" and has rubber edging. |
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| Gluegun |
Okay. You have been quite confused.
Why not pull out the specs sheet for these things:
The speakers themselves
What you have DRIVING the speakers
and tell us exactly what all the numbers say? You are misinterpreting the numbers quite badly, so why not simply quote the numbers for us experts? |
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| b i n k u n |
possible reasons for that:
1) your amplifier is weak or not enough to power you speakers. the amplifier wattage should be almost double your speaker wattage.
2) differet designs of speakers give different sounds. maybe your speaker doesn't even reach down under 40 Hz do give you that rumble and thump that others do.
3) speaker placement makes a difference. a speaker in the corner gives more bass then a speaker in the center of the room. (altho i strongly discourage putting the speaker in the corners unless you have to.)
4) your speakers are old? i really don't know...
there are lotsa possible reasons... |
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| DjJade |
| yeah speaker placement and enclosure have alot to do with that... what speaker is it...where is it... does the bass response change as you walk around the room? |
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| MERiDiAN5i2 |
| quote: | Originally posted by Kid Lax
i thought it was every 3db incriment it sounded twice as loud |
3db in relation to power is a doubling - ie 100 watts is 3db over 50 watts. |
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| MERiDiAN5i2 |
| quote: | Originally posted by Project T
what i would really like to know is that i have 400rms output speakers that supposedly go up to -96 Db or whatever :confused: and that the bass climbs no louder after 3/4 of the volume is reached. and why people with much smaller bass cones than me get much more sound even though my bass cone is about 8" and has rubber edging. |
be aware that bass in much better driven by current rather than voltage (IE likes lower impedances) - most amps can only push so much current, but can generally push higher voltages easier than higher currents. so it's easier for them to generate higher frequencies. of course this is all dependant on the imppedance curve of the speakers.
also, you may have simply reached the travel limit of the woofer.
try using a subwoofer to achieve your bass, and use a high pass filter to save your mains the hastle of thumping so much.. and use a high current amp to drive your low impedance subs. |
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| Dj Flesch |
okay, well since no one bothered to follow the link I provided, here is an exert from the pages: click
here to read the whole thing)
"The calculations for the dB relationships I just gave go like this; for a 10 to one relationship, the log of 10 is 1, and ten times 1 is 10. For the 2 to one relationship, the log of 2 is 0.3, and 10 times that is 3. Incidentally, if the ratio goes the other way, with the measured value less than the reference, we get a negative dB value, because the log of 1/10 is -1."
So, yes, a sound twice as loud as another source is 3 dB louder. |
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| DjJade |
no from that calculation that you just put in... its decibels calculated in terms of power. its not twice as loud, it takes twice the power to make it 3 db louder... 3db is the threshold that the human ear can tell a defference in loudness.
notice the equation above your exerpt...
"Power difference in db= 10 log [(powerA)/(PowerB)]" |
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| DjJade |
also from your website
" First of all, the ear is very sensitive. The softest audible sound has a power of about 0.000000000001 watt/sq. meter and the threshold of pain is around 1 watt/sq. meter, giving a total range of 120dB. In the second place, our judgment of relative levels of loudness is somewhat logarithmic. If a sound has 10 times the power of a reference (10dB) we hear it as twice as loud. If we merely double the power (3dB), the difference will be just noticeable."
which is what we all have been saying |
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| b i n k u n |
agree with DJ Jade's post.
i think it may be easier for everyone if you try NOT to think of power and volume on the same page. power is measured in watts; volume or how our ears hear sound, is measured in SPL (sound pressure level or dB). there is no real direct correlation between watts and dBs.
for the point of buying speakers...you rarely need to worry about dB levels up past 60 or so dB unless you are going professional and are mixing a live show, run a club sound system, and the likes. inside your house you rarely need sound THAT loud. for adequate sound, make sure your amplifiers are strong, that is usually more important. |
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| Dj Ricky H |
| quote: | Originally posted by tristan_vdv
umm, RMS stands for Root Mean Square, not Real Music Sound |
RMS in audio world means Rated Manufactures Specification ......:D |
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| DjJade |
no rms is root mean squared... when you have an amp hooked to a speaker, the amp puts out power in a function with respect to time. it peaks at its max wattage but you take the rms of it and that is the average power that the amp puts out continuously.
so the square of the root mean square is the square of the average (deviation from the average) squared
(rms)^2=<(x-)^2> |
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