Glossary-ice-terminology

[kb100]

Can the gurus pls explain Damping Factor.... ?? and its relevance..

[low_bass_makker]

The damping factor indicates the ability of an amplifier to resist a change in it's output signal.

here u can read the whole topic clearly explaining in detail....

http://www.bcae1.com/dampfact.htm

[ghostrider4385]

Ok now, there are 2 terms I see everybody keep arguing about, like the suzuki honda-wars... SQ & SPL.... what are they?!

Godspeed.

Alok.

[jkdas]

SQ: Sound Quality

SPL:Sound Pressure Level

Clipping: Audible distortion that occurs when a signal's level exceeds the limits of a particular device or circuit

decibel (dB): A relative and dimensionless unit to measure the ratio of two quantities

Equalizer : A signalprocessing device that can boost, attenuate, or shelve frequencies in a sound source or sound system

Sensitivity:The soundpressure level directly in front of the loudspeaker, onaxis, at a given distance and produced by a given amount of power

Sound frequeny spectrum: The range of frequencies audible to human hearing: about 20 to 20,000 Hz.

Treble: Frequency range between roughly 5,000 and 20,000 Hz, the highest two octaves in the audible hequency spectrum.

Tweeter: A loudspeaker that reproduces high hequencies (5,000 and 20,000 Hz).

Bass: The low range of the audible frequency spectrum; usually from 20 to 320 Hz

Woofer: A loudspeaker that produces the bass hequencies.

[ghostrider4385]

And by Sound Pressure Level, I assume you mean bass. Am I right?

Godspeed.

Alok.

[rsjaurr]

no,not just bass.
Can be called loudness in simpler terms.

Which one u r going for!!!!

[jkdas]

Originally Posted by ghostrider4385

And by Sound Pressure Level, I assume you mean bass. Am I right?

In a way, yes. But usually real heavy, heart pounding bass, 90-100dB plus? What say guys?

' SPL is to describe the efficiency of their speakers. The most common means is measuring the sound pressure level from the speaker with the measuring device placed directly in front of and one meter away from the source. Then a particular sound (usually white noise or pink noise) is played through the source at a particular intensity so that the source is consuming one watt of power. The SPL is then measured and the product labeled something like "SPL: 93 dB 1 W / 1 m" ' frm wilki

[low_bass_makker]

From my side for db scale in layman terms...

[navin]

Sound Pressure Level means eaxactly what it says. However it must be defined at a particular distance, over a particular frequency range, etc.

SPL is usually referenced as average energy over the entire audio spetrum. However music with "equal energy" over the entire audio spectrum is not always nice to listen to. Human hears are extrmely non-linear and psychoacousitcs plays a huge role in how we listen to sound in a reverbrant field. So when one says a speaker can produce 100db @ 20W @ 1m one assumes the speaker can do this over the entire audio spetrum in a reverbrant field (in a anechoic field this is many times more diffcult and not practical).

The problem is that SPL s a term that is much abused. To produce high levels of SPL in the bass requires much larger ammounts of energy than in the midrnage. In fact below 200Hz this requirement of energy balloons rather fast. For example a loudpspeaker can eaily produce 100db at 400Hz at 20W but the same 20W at 50Hz might only produce 90db in a anechoic field. That means 1/10th the SPL at 50Hz than at 400Hz!

In addition to this the human ear is notoriously insensitive to low frequencies meaning that the poor loudspeaker must in reality produce higher SPL at low frequencies than in the midrange to SOUND flat. Thankfully (in part) we live in apartments and houses. Loudpseakers get quit a bit of help from the room boundaries in the low frequencies. Which is why when your speakers that sound so lovely at home are taken outside they sound aneamic.

Most GOOD speaker designers understand that we live in apartments and houses and design loudspeakers to SOUND flat (within reason and budgets) in such an enviroment. The same goes for Automobiles.

In india we are a bit luckier in that most of our construction is cement and brick which offers a sturdier boundary than wood and sheet-rock.

[kb100]

some amps specs show "channel seperation >70" .. what exactly is this and whats its significance?

[low_bass_makker]

channel seperation ->Refers to the inverse of the crosstalk between the channels of a stereo amplifier. The higher the value (in decibels) the better the isolation of the two channels. Crosstalk refers to a leaking of a signal from one channel to another channel of a stereo amplifier. Crosstalk is almost always measured in decibels.

[kb100]

what therefore should be the acceptable range of separation of poor/avg/good/excellent amp etc? .. Will halp if we can post some refernce values..

[navin]

60db channel seperation in a car is adequate.

[Autophile]

Originally Posted by navin

60db channel seperation in a car is adequate.

Any particular reason why 60dB is adequate?

I have done a AB comparison between Alpine amp with 60dB S/N ration and the other two amps with similar power but with S/N ratio more than 100dB. They kicked Alpine out of the world.
To be honest Alpine amps are going down every year in sound quality.

Last good Alpine amps I considered worthwhile was in the era of 340 / 540 / 501 / 1001

[kb100]

Originally Posted by Autophile

Any particular reason why 60dB is adequate?

I have done a AB comparison between Alpine amp with 60dB S/N ration and the other two amps with similar power but with S/N ratio more than 100dB. They kicked Alpine out of the world.
To be honest Alpine amps are going down every year in sound quality.

Last good Alpine amps I considered worthwhile was in the era of 340 / 540 / 501 / 1001

JB... is "CHANNEL SEPERATION" the same as "SIGNAL to NOISE RATIO" ??

S/N ratio = > 100 dB
Channel Seperation = > 70 dB

What would this mean??? ... both technically.. and in terms of sound..??