I never thought Ligonier was a fancy town with "rich little turds" running amuck...
Maybe it was the area I ventured into when buying the Beretta... It was back along the tracks right across from the Kraft Foods factory...
Haha anyhow, cant wait until it gets open. I will come over!
LoL yup you have been here. I'm actually hoping to attract more business from the surrounding area and you would be surprised some of the people around here have money mainly because of all the trailer factories and stuff like that around here. Hell my wife and I have a combined weekly income of over $1600 bring home. Not too mention some of the amish kids that are at that age where they get to live like the english to decide which life they want... they spend shit loads of money on cars, boats, all kinds of things and they all want a system in there grand am I swear this place is thick with them lol
intermodulation distortion isnt an amplifier problem though...i see your point though and am in total agreement
Yeah I don't consider it ripping them off if I explain the advantages of the higher end equipment and they still insist on the lower end and it comes down to either I get the money or someone else does so why not me.
GlassWolf wrote:depends on the type of distortion. intermodulation distortion sounds like unadulterated ass. so do even ordered harmonics, but look at a tube amp.. running 10%THD od ordered and people call them desireable and "warm."
Fully agree. Most of the "high end" $12,000 8W tube amps are made to cater to corrupted taste. Add the PITA of rebiasing, tube replacement, and degradation of performance over time (until said tube replacement and rebiasing), I see no need for tubes to exist anymore. Unless you're really all that worried about the occasional EMP striking your beloved amplifier.
any solid state amplifier used within the limits of it's power supply, and with the input sensitivity set properly will work fine for pretty much any application without any audible distortion. It's been pretty much proven beyond any reasonable doubt that no two amps can be told apart by their "sound quality," and that a watt is a watt.
Also keep in mind that speakers by their very nature produce at least 10% distortion anyway so a speaker is going to distort far more than any amplifier will, making the THD of an amplifier a moot point.
more on distortion from the FAQ section:
Distortion
ALL amplifiers alter input signals, generally in two ways: they make them stronger (amplify them), and they add characteristics which did not exist in the original signal. These undesirable characteristics are lumped together and called distortion. Noise can be considered a type of distortion and was discussed in the above section.
Everyone is familiar with gross distortion, the sound quality that results when turning up a radio or boom box to "full blast”. An excessive amount of amplifier clipping (see section below) results in hideous distortion that would be totally unsatisfactory for a sound system. However, not all distortion is blatant. In addition, there are several types, two of which will be discussed. Knowing what causes distortion will help you to prevent it from occurring. Knowing how to control distortion is important because excessive distortion can be detrimental to speaker systems (and your reputation).
Harmonic distortion: One common type of distortion is harmonic distortion. Harmonics of a signal are signals which are related to the original (or fundamental) by an integer (non decimal) number. A pure tone signal has no harmonics; it consists of only one single frequency. If 100 Hz pure tone signal was applied to the input of an amplifier, we would (upon measurement with special test equipment) find that the output signal of the amplifier was no longer pure. Careful measurements would likely show that several "new" frequencies have appeared. These new frequencies are almost certain to be integer multiples of the original tone; they are the harmonics of the original signal. In the case of a 100 Hz input tone, we might expect to find tones at 200, 300, 400, 500 (etc.) Hz. We would also probably notice that the odd harmonics are much stronger than the even harmonics (we will not go into the reasons why in this article). In a good amplifier, the harmonics will be much weaker than the original tone. By much weaker, we mean on the order of a thousand times for decent amplifiers.
All amplifiers are generally rated for Total Harmonic Distortion (or THD), usually at full power output over a given frequency band with a particular load. Good values are anything less than 0.5% THD. When an amplifier is measured for THD, a pure tone is applied to the input and the output is measured with special test equipment. The energy of the pure tone is measured, and the energy of the harmonics is measured. Those two values are compared, and a THD rating is calculated. A THD rating of 1% means that the total energy of all the harmonics combined is one one-hundredth of the energy in the fundamental.
Harmonic distortion (although certainly undesirable) is one of the more tolerable types of distortion as long as it is kept reasonably low. Distortion levels of 10% may be very tolerable with music so long as the 10% level is only "occasional." (10% THD on a pure tone can easily be heard by the human ear... but who listens to pure tones?) The reason that a seemingly high value of THD is acceptable for music is partially because many sounds in nature are rich in harmonics. Also, most decent cassette decks (which most people agree sound pretty good) have THD (off the tape that is) of several percent. Worse, even good speakers can have THD up to 10%, especially at low frequencies! All in all, the human ear can tolerate a fair amount of THD before it becomes objectionable.
Do two amplifiers with identical THD ratings sound the same, everything else being equal? Not necessarily (but differences will be subtle). The reason is that the THD specification states nothing about where the harmonics are in the frequency band. For example one amplifier could have a dominant harmonic at one frequency and a second amplifier could have a dominant harmonic at a very different frequency. Or, one amplifier could have a few "big" harmonics while a second has many weak ones. These situations could easily result in identical THD ratings. The variations could be easily measured with laboratory equipment. However do not be overly concerned. Minor variations in THD ratings will not cause major differences in sound when listening to music. With pure tones as input signals it might be fairly easy to discern which of two amplifiers was used (but again, who listens to tones?)
Intermodulation distortion: Intermodulation distortion is the second "major" type of distortion that is often specified for amplifiers. Intermodulation distortion is much more objectionable to the human ear because it generates non-harmonically related "extra" signals which were not present in the original. It is analogous to someone singing way off key in a choral group
Intermodulation distortion (sometimes abbreviated IM) is more complicated to test for and specify. Basically, two pure tones are simultaneously applied to the input of the amplifier. If the amplifier were perfect, the two tones (and only the two tones)would be present at the amplifier output. In the real world, the amplifier would have some harmonic distortion (as described above), but careful observation of the output signal (using laboratory equipment) would reveal that there are a number of new tones present which cannot be accounted for as a result of harmonic distortion. These "new" tones are called "beat products" or "sum and difference" frequencies, and are a result of the interaction of the two pure tones within the amplifier. No amplifier is perfect, all have some non linear characteristics. Whenever two signals are applied to a nonlinear system, new signals (in addition to the original two) are generated. For a good amplifier, the new signals are very small in relation to the two original tones. This is fortunate, since the ear can detect much lower levels of intermodulation distortion as compared to harmonic distortion.
It should be noted that distortion measurements on amplifiers are made with test tones. These tones are usually sine waves (pure tones), which represent the simplest possible test signal to measure and quantify. A music signal is an extremely complicated waveform consisting of many constantly changing sine waves. Since music has so many harmonics and frequencies present, quantifying how two different amplifiers will sound by using simple THD and IM specifications is extremely difficult. In other words, just because two amplifiers have the same published specs for THD and IM does not mean that they are equivalent. Fully and completely quantifying the technical performance of an amplifier would be extremely complicated and costly (and would probably have little benefit in the end). Most amplifiers available today (from reputable manufacturers) have THD and IM levels low enough to yield excellent performance (so long as they are not overdriven).
ok it not ONLY an amplifier problem....it is usually a problem caused when for example the tweeter stem and tweeter itself are caused to vibrate due to the frequencies played by the woofer......
Thanks glass I thought I had read that somewhere before (probably a post by you) I was considering using one of the big ass amps (don't remeber the model # atm) to power 4 elevation pro 12s for my truck. I would use to dx1500.1s but I want to display/use as much of the stuff I sell for demonstration purposes.
well I'm hoping to start doing business out of it within the next couple of weeks, my wife is mixed on car audio, she doesn't share my passion for it but after hearing her favorite song in my car she demanded some "Boom Boom" in her car so when I get my truck done I'm going to start working on and SQ system for hers, I think the car would be an awsome sq car and with the variety of music she listens too and the volume range she usually has it in I think she would appreciate it a lot more, of course anything that involves tricking out Tibby she is down for :P
This is Tibby btw.
GlassWolf wrote:depends on the type of distortion. intermodulation distortion sounds like unadulterated ass. so do even ordered harmonics, but look at a tube amp.. running 10%THD of odd ordered and people call them desireable and "warm."
Jonathan wrote:Fully agree. Most of the "high end" $12,000 8W tube amps are made to cater to corrupted taste. Add the PITA of rebiasing, tube replacement, and degradation of performance over time (until said tube replacement and rebiasing), I see no need for tubes to exist anymore. Unless you're really all that worried about the occasional EMP striking your beloved amplifier.
Yop. I love how The Audio Critic breaks down his disdain for the rave about tube amps. I mean, to each his own. Everyone has their own sets of ears, but I just enjoyed his method of elaborating on the that tube amps have received over the years. Pretty similar actually:
smoker, wasn't disputing you, just expounding on my previous statement so others would have a better idea of what we were talking about.
end result is THD ratings on amps are pointless by themselves, and not something to pick or pan an amplifier based upon solely when making a decision.
amplifier distortion, when the amp is used within it's limits, is inaudible.
So in basics I won't be doing my customers wrong if I offer them Interfire amplifiers as an money saving option and recommend they spend the extra they save on higher quality speakers when on a limited budget
that tube amps have received over the years. Pretty similar actually: