
	Where results make sense

Topic: Nominal impedance

Related Topics

Internal impedance

Characteristic impedance

Impedance

Balun

Guitar amplifier

XLR connector

Microphone

Loudspeaker

Decibel

Reverberation

Fret

Bass guitar

Diverticulitis

Maritime flags

Pickup

In the News (Tue 1 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Nominal impedance - Wikipedia, the free encyclopedia
		Most signal-processing equipment is designed to operate with the internal impedance of a signal source much smaller than the load impedance of the input to which it is connected.
		This means that the characteristic impedance of the cable is close to one of these figures.
		The effective impedance of input or output is the equivalent impedance of all of the output or input circuitry of a device lumped into one (imaginary) component.
	en.wikipedia.org /wiki/Nominal_impedance (512 words)

	Audio Allies Definition for: Impedance (Site not responding. Last check: 2007-10-13)
		Impedance is what restrains the flow an electric current making it more difficult for the current to move through a circuit.
		Impedance is similar to a dam in a river.
		Generally, receivers should be mated with speakers having a nominal impedance of 8 ohms or so while separate amplifiers may be used with speakers with nominal impedances of 4 ohms or so.
	www.audioallies.com /GetFeatureDesc.asp?Feature=Impedance (628 words)

	Peavey.com :: Impedance in Audio Technology (Site not responding. Last check: 2007-10-13)
		When discussing a technical subject such as impedance, it is necessary to employ mathematics to illustrate the relationship between voltage, current, impedance, and the resultant power produced in the circuit.
		The actual impedance varies with frequency, and it is for this reason that many manufacturers publish impedance charts that will indicate at what frequency the impedance is at its minimum.
		Third is the impedance of the air or the acoustic impedance that the combination loudspeaker/enclosure encounters.
	www.peavey.com /support/technotes/concepts/impedance_2.cfm (2696 words)

	RF Connection Coaxial Cable
		Nominal impedance 50 Ohms, velocity of propagation 84%; outer diameter.240"; 100% Al mylar and 95% tinned Cu braid.
		Nominal impedance 50 Ohm; velocity of propagation 65.9%; outer diameter.405"; 98% Cu braid.
		Nominal impedance 75 ohm; velocity of propagation 65.9%; outer diameter.242"; 98% Cu braid.
	www.therfc.com /coax.htm (1305 words)

	Microphone impedance
		The nominal load impedance for a mike indicates the optimum matching load which utilizes the mike's characteristics to the fullest extent.
		Impedance is a combination of de resistance, inductance and capacitance, which act as resistances in ac circuits.
		An inductive impedance increases with frequency; a capacitative impedance decreases with frequency.
	lp2cd.com /audio_terms/m/microphone_impedance.html (124 words)

	Nominal watt - Wikipedia, the free encyclopedia
		Nominal wattage is used to simplify the measurement of the efficiency of a loudspeaker.
		The impedance of a loudspeaker varies with frequency.
		This permits a loudspeaker to be used with an amplifier having a low internal impedance and a flat frequency response is realised for the combined amplifier/loudspeaker system.
	en.wikipedia.org /wiki/Nominal_watt (393 words)

	Understanding Impedance (Site not responding. Last check: 2007-10-13)
		The output voltage from the source is developed across the input impedance of the destination (often called the load impedance, or simply the load), and therefore the signal voltage is passed from source to destination.
		The impedance of a headphone is determined by the design of its voice coils — the length and size of wire used, the number of turns around the former, and so on.
		The use of the transformer is principally to translate the effective load impedance between that required by the valves, and that of a practical loudspeaker —; a typical valve output circuit requires a load of between 5k(omega) and 10k(omega), whereas a practical loudspeaker presents a nominal impedance of between 4(omega) and 15(omega).
	www.soundonsound.com /sos/jan03/articles/impedanceworkshop.asp (5518 words)

	Fitted Versus Input Impedance
		Impedance is the ac resistance to the flow of electrical current.
		SRL is a measurement of the difference between the input impedance at a given frequency and the nominal impedance at that same frequency.
		When the input impedance is the same as the nominal impedance, there is no return loss (or SRL becomes a large negative number).
	www.belden-wire.com /College/Techpprs/ftvimptp.htm (867 words)

	epanorama.net/Speaker impedance
		There is a convention to the use of the term "nominal impedance", and if the impedance over the majority of the bandwidth, specifically covering the range in spectrum where majority of the musical spectral power occurs, it's 8 ohms.
		At fundamental resonance, the impedance is purely resistive, its phase angle is 0, and is determined by the effective series combination of the voice coil DC resistance and the reflected mechanical losses of (primarily) the suspension (Re + Res in standard Thiele/Small notation).
		The impedance of a speaker is only a rough average of the impedance and that the the voice coil dc resistance of most normal cone type dynamic speaker is roughly 75% of its "rated" impedance as the industry rates impedance.
	www.epanorama.net /documents/audio/speaker_impedance.html (1982 words)

	4ohm vs 8 ohm speakers - implications? - Audioholics Home Theater Forums
		It's important to remember that loudspeaker impedance changes with frequency to the impedances given by manufacturers are nominal or average over the frequency range of the loudspeaker system.
		The nominal impedance of a loudspeaker or driver is the "typical" impedance throughout most of its operating range.
		Impedance is specified in ohms, and resists (impedes) current flow.
	forums.audioholics.com /forums/showthread.php?t=396 (1774 words)

	I'd Like My Cabling System Optimized Please - Siemon
		Although not a standard’s requirement, the impedance performance of the channel was plotted versus frequency as shown in figure 2.
		The time-domain equivalent of the impedance performance is plotted versus length in figure 3.
		Because of the inherent variances in the frequency response of impedance over long lengths of cable, it is impossible to design a cabling system that is precisely 100 ohms across the entire frequency range.
	www.siemon.com /uk/white_papers/00-12-08-optimized.asp (901 words)

	Symphony Sound - Tube Friendly Speakers
		Impedance, for the purposes of this discussion, may be thought of as the AC equivalent of DC resistance.
		Bear in mind that the nominal impedance is only a useful figure in the context of the minimum impedance.
		This speaker has a published nominal impedance of 8 ohms, which might be a little optimistic but nevertheless it only dips below 6 ohms briefly on a couple of occasions and when it does so, the phase angles are either slightly capacitive or inductive.
	www.symphonysound.com /articles/tubefriendly.html (3199 words)

	Loudspeaker Impedance
		Impedance is AC resistance and differs from DC resistance in that impedance changes with frequency.
		Nominal means, somewhere around, about, average, could be, that's what we want you to believe, we think it is or just about anything.
		In Figure-D you see an impedance curve of the Mid/High section of a touring loudspeaker whose low frequency crossover point is at 250 Hz, active, and the high frequency is passive.
	www.churchsoundcheck.com /imp1.html (971 words)

	Mc Squared System Design Group, Inc. - Interpreting Loudspeaker Specs
		Look for an indication of whether the rated impedance is the "nominal" rating or the minimum impedance rating.
		Also note that most of these drivers that are rated for 16 ohms nominal, reach a minimum impedance of between 10.5 and 12 ohms in the middle of their operating range.
		Where minimum impedance is lower than nominal, and the test signal bandwidth includes the minimum impedance point, it can skew the sensitivity rating.
	www.mcsquared.com /nsca98.htm (2813 words)

	Speaker impedance (Site not responding. Last check: 2007-10-13)
		The better the speaker (generally) the less the nominal impedance will change in any given situation.
		In some experiments way back in high school (and I do mean way back), I could get the impedance of a speaker to change by a factor of 2 by simply positioning it in different spots in the room.
		Changing the impedance of a speaker (or more accurately its DC resistance) opens up a whole other can of worms.
	www.newton.dep.anl.gov /newton/askasci/1993/eng/ENG19.HTM (405 words)

	Stable delay buffer - Patent 6150862
		However, when stable delay buffer 301 is operating within an intended nominal range, the impedance of the impedance source will tend to vary along its slope within some nominal VT range, as shown by Z5 and Z4 of FIG.
		In this example, the nominal delay of signal at node 307 (without active load circuit 305) would be decreased by t2-t3 (t2-t3), as shown by signal 605.
		In this configuration, the passgate that serves as the impedance source is set to be 1030 or 1040, depending on the input signal transition direction.
	www.freepatentsonline.com /6150862.html (6109 words)

	Passive Crossovers: The Impedance Of Speakers
		Actually the nominal impedance, that specified on catalogs, has the only purpose to divide speakers in families, depending on the type of use which they are intended for.
		Being the nominal datum referred to an only frequency, what's more in approximate way, and being instead the impedance variable with the frequency in real life, it stands to reason that you can't refer to this value for the calculation of the filter.
		It is possible to describe the impedance assumed by the moving coil at different frequencies in graphical form on a cartesian plan, with the scale of frequencies in abscissa (Hz) and the impedance values in ordinate (Ω).
	www.passivecrossovers.com /section13.htm (449 words)

	X-Topic4 (Site not responding. Last check: 2007-10-13)
		However, the band-pass filters in X•over Pro can easily result in an impedance that is less than half that of the net nominal impedance of the midrange driver(s).
		For example, the amplifier may see an impedance in the midrange passband that is less than 4 ohms if the midrange driver has a nominal impedance of 8 ohms.
		This is necessary because raising the passband impedance of the band-pass filter and midrange driver(s) will reduce their sensitivity.
	www.ht-audio.com /x-topic4.htm (968 words)

	Modeling Impedance with Tabular Data in AC Analysis - Spring 2006
		One method to model a complex impedance is to combine resistors, inductors, and capacitors together until the impedance versus frequency curve matches the expected results.
		At this point, it will be assumed that the impedance magnitude and phase versus frequency for the loudspeaker has already been obtained through measurement of a physical device, from a data sheet, or through another program.
		The impedance of the speaker output is calculated by using the expression V(Out)/I(H1).
	www.spectrum-soft.com /news/spring2006/acimped.shtm (826 words)

	Zero Autoformers, Impedance Multiplying Transformers [English]
		Impedance matching between amplifiers and speakers is no less important, especially since the ability of an amplifier to control driver movement, the damping factor, is directly related to the ratio of amplifier output impedance and speaker impedance.
		In addition, when considering low impedance loudspeakers, some manufacturers specifically state that their amplifiers should not be used with planar speakers like Magnepans because the speaker impedance may dip below a level considered safe for the amplifier.
		It is easy to understand the benefits of raising the speaker's impedance for an OTL amplifier, but people have a harder time accepting the possible benefits of adding an autoformer in front of solid state amplifiers and tube amplifiers that already have multiple output taps.
	www.tnt-audio.com /accessories/zero_autoformer_e.html (2555 words)

	PSW Sound Reinforcement Forums: LAB Lounge => Nominal impedance
		Loudspeakers may be nominally 4 ohms but if you look at an impedance vs. frequency sweep it may only touch 4 ohms a couple times within it's usable bandwidth.
		When considering the impedance of a loudspeaker what is just as important (or more inpportant) is the phase of the impedance.
		So as a very general rule of thumb the minimum impedance of a speaker would be around 80% of the nominal value or, conversely, the nominal impedance is around 1.25 times the minimum value which is typically then reported as the nearest "standard" value.
	srforums.prosoundweb.com /index.php/m/156280/0 (1236 words)

	Impedance, and how it affects audio equipment
		There are a multitude of impedances involved in a typical amplifier to loudspeaker connection, most of them having a vastly more profound effect than the amp's output impedance alone.
		To be meaningful, the impedance should be quoted at at specific frequency, or preferably at a range of frequencies.
		Generally, it is desirable that the output impedance is low, and the destination impedance high, and this is the case with the majority of modern equipment.
	sound.westhost.com /impedanc.htm (5822 words)

	TA Speaker Topics - Neutralizing L(e) with a Zobel
		A Zobel can be used to restore the impedance of the driver to the nominal value in the high frequency range.
		Next, calculate the value of the capacitor from the nominal impedance and the driver’s L(e) value.
		The impedance of the woofer will also be restored to the driver’s nominal impedance throughout the high frequency range.
	www.trueaudio.com /st_zobel.htm (656 words)

	Connecting Speakers
		The term is Nominal Impedance and the unit is ohms.
		Re is the resistance of the voice coil, and is close in value to the nominal impedance.
		Let's say we have two subwoofers that have a nominal impedance of 4 ohms each.
	www.teamrocs.com /technical/pages/connectingspeakers.htm (375 words)

	diyAudio Forums - Crossover question
		The stated impedance of all drivers is an averaged figure within their nominal passbands.
		Crossover component values are usually chosen according to the nominal impedance, though extreme deviation from the nominal at the crossover frequency could require addressing that circumstance.
		To add to that, impedance-compensation networks are often used to flatten out the impedance curve of drive units, making them easier to design the crossover for.
	www.diyaudio.com /forums/showthread.php?postid=452096 (326 words)

	Stereophile: Cary Audio Design CAD-805 monoblock power amplifier
		The nominal impedance should be 8 ohms or higher, and ideally there should be no dips below 4 ohms—at least below 500Hz.
		The Model 3-SE ($2995/pair) is said to possess a 6 ohm nominal impedance and is rated at 95.5dB at 1W at 3m.
		While I believe the 6 ohm nominal impedance rating is reasonable, the sensitivity figure is straight out of the Twilight Zone.
	www.stereophile.com /amplificationreviews/740/index2.html (1118 words)

	If I plug in more than one speaker to my system and turn the volume past 3, the receiver shuts off. If I have only one ...
		Impedance varies with the frequency of the input signal and, for an 8 ohm (nominal) speaker, may fall to as little as 3 or 4 ohms at some frequencies and rise to over 50 ohms at others.
		Higher impedances are not a problem, but if two speakers are wired in parallel, their joint impendance halves (assuming they are the same design).
		Hence, a pair of nominal 8 ohm speakers wired in parallel would have a nominal impedance of 4 ohms.
	www.answerbag.com /q_view.php/10111 (427 words)

	Ultimate AV: Cambridge SoundWorks Newton Series T500 surround speaker system
		Below 500Hz the impedance rises, which might indicate a capacitor in the mid-tweeter circuit to protect it from overload.
		A conservative rating for the nominal impedance would be 5ohms.
		The impedance is very capacitive at 56Hz, but the magnitude is 15ohms at this point, so the speaker should not be difficult to drive.
	www.guidetohometheater.com /speakersystems/87/index4.html (476 words)

Try your search on: Qwika (all wikis)