WMcD
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Posts posted by WMcD
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Welcome to the Klipsch family.
However, the Pro Media cousins have another section of the bbs. I'm sure you will find some assistance if you post there. It is just a few steps farther below.
Regards,
Gil
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This is my experience with HT reveivers too.
Even if the amplifier circuits are not noisy, the DSP circuitry is. Therefore, if you're in a setting without DSP, the receiver is not too "hissy". But with any sort of DSP doing even 3 channel stereo, the added circuitry is not so good as far as noise floor.
Specs on receivers may not report this sort of thing accurately.
Gil
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One question which comes up from time to time is how to shield speaker magnets in our beloved speakers so they don't mess up CRTs in HT systems.
I just had to retire a Sony monitor of 1987 vintage. It died from causes unknown and it did not seem worth the investment of repair.
However, I extracted the speakers.
They have a diaphragm measuring about 1 inch by 3 inches. No wonder TV audio is so improved by feed to even the most elementry stereo system.
However, I note these speakers have a shielded, round, magnet. I have not made any measured comparison, but the shields might be able to be adapted to a K-77 with the round magnet.
The overall thought is that we should be alert to salvaging mu metal shields from old TVs and adapting them to the Heritage series.
Maybe in times future there will be shielded "woofers" in consumer TVs which can be adapted to the K-55 series.
Gil
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Robert G., I must defend my tarnished honor, Surrh.
I might give advice devoid of all technical merit. Or advice which is unwelcome because it is intuitively obvious to the casual observer and an insult to the intelligence of the reader. But "bad advice"! Bad Advice? Thems fighten words.
Dual trace 'scopes at 20 paces may be the appropriate weapons for dueling. We'll see how far we can throw them at each other.
Please know the above is in the best of good humor. I'm happy read your comments. In truth, there may have been a misunderstanding.
In my defense, please consider that I actually wrote:
"I would make sure that ALL electronic components are grounded though a copper connection independent of the chassis. But then I'd connect that bus to the battery negative.
Bob G., after characterizing my response as "bad advice" , wrote: "Grounding the head unit DIFFERENTLY than the amp in the rear is part of the problem."
By writing "all", I was trying to express that the head unit, the amp, and any other components, should be grounded the same.
A close reading shows that Bob G. and I are in accord on the overall issue.
I also agree ground loops can be a difficult, vexing problem.
Best regards,
Gil
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Not an audio question, but I submit it to the brain trust here.
What is the nature of the output of a DVD player?
Some of e-mail buddies say they can't see the difference between HDTV and a good NTSC montior.
Now I'll admit that HDTV and DVD don't advertise to be the same.
None the less, I've seen some rear projection wide screen displays at the Sony showroom, and a Toshiba at a Tweeter. In both cases, the feed was from a DVD player.
Can it be this is NTSC letterbox format enhanced with line doubling and progressive scan? It sure looked very good to me.
A link to a website would be fine.
Regards,
Gil
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Some systems are set up so the second woofer turns on at low frequencies. Consider it simply a matter of a subwoofer turning on. Everyone likes subs.
It is correct to suspect that two drivers which are both active at higher frequencies could cause problems.
At certain listening positions, and certain frequencies, your ear can wind up being half a wavelength farther from one than the other. (I.e. the path length difference to your ear is half a wavelength.) Half a wavelength means they are out of phase. The waves cancel.
Lets consider 1000 Hz. The wavelength is about a 1 foot. It IS possible for the path length difference to be 1/2 foot.
However, this is not a problem at low frequencies. At 100 Hz, for example, the wavelength is about 10 feet. With the two woofers mounted in the same cabinet, it is impossible to have a path length difference of 5 feet. The geometry makes it impossible. So it is not a problem.
Gil
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I'm quite confident a call to the factory will get you some excellent help. Trey Canon is renound for tech support.
In the mean time you might want to look at a post, and responses, in the Trouble Shooting section of this bbs. It is dated April 8 and is entitled, "Puke on My Speakers."
We were pleased to see that turned out to be an inquiry and not a invitation.
Yes, the poor fellow had a problem with gastic juice on his fabric grills. Our fearless moderator, Bob G., had comments based on experience. =8^o
If there is smoke in the cloth, there may also be smoke on the finish. One guess is that one of the standard mineral oil and lemon oil 'polishes' will help get the grunge off the wood.
Regards and congrats on your purchase.
Gil
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I can best offer some theory you can appreciate and brute force solutions. You're already working in this direction. So please excuse the obvious.
It sure sounds like a "ground loop."
This occurs when there is current flowing in the ground lead of the signal line. I believe there are two outcomes.
First, the field induces a voltage in the center, signal, conductor. So we have to ensure that can't happen.
A second issue may be that the ground connector of the signal like doesn't have enough resistance to keep the respective chassis at zero volts. The input is considered how much the center of the RCA is above the ground/shield input. If the ground is noisy, the the input of the amp reads noise even if the center channel is at zero volts.
I would make sure that all electronic components are grounded though a copper connection independent of the chassis. But then I'd connect that bus to the battery negative.
Again, it sure sounds like a ground loop . . . but where is the hash coming from in the first place.
There is something to be considered in the relation between the alternator and the battery. My understanding is that the alternator is actually a three phase a.c. generator (alterator). The raw output is the superposition of the three rectified sine waves. The battery serves somewhat as a capacitor to integrate out the ripple. In truth, the lead acid battery should act as a nearly a perfect voltage source, rather than a integrator.
It may be that a power supply lead to the electronics is not connected directly across the battery. That is allowing some hash into the power input to the head unit. Perhaps something like a 20 uF capacitor from the positive power lead to ground at the head unit will reduce the hash on the power lead. (Watch for polarity of an electrolydic cap, naturally.)
Overall, again, I'd make certain all grounds are through a bus dedicated to the electonics.
One technique need some discussion. Make sure the RCA connection's shield is not connected on both ends. That ensures that no current can flow in the shield. This might work best if the "ground" of the electronics really are at a common battery ground.
Best I can think of right now.
Gil
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I started work on the transformer story the other night. But the computer ate my homework. Back to the word processor.
A work project is going to prevent me from doing anything "educational" for a couple of weeks. Also, I should buy a scanner so we can have some diagrams to look at.
Thanks for kudos re writing. It is part of my profession.
May I point out that many of the posts on the bbs are a bit unclear. That is not because of lack of content. Rather, people have not been breaking up the text into paragraphs.
If you want a "works every time" tip: Do try to put three sentences into each paragraph, plus or minus one. Do try to put one thought in each paragraph. If you have more than one, hit the return key to break it up.
You don't have to put all the connected thoughts into one sentence so that we start with the beginning and go the middle and then to the end and go back to explain how the middle step relates to the beginning step and to the end step which they are both connected to but I'm not sure where to put a period because then they're not connected but I wanted to let you know they're all connected in my humble opinion but then most things are opinion. =8^o
It is a rote matter, but it (use of paragraphs) works every single gosh darn time. Spelling and punctuation count. Errors there, however, do not grossly effect readability or clarity of thought.
It is always a pleasure to write about what you love, to a receptive audience. I love this stuff. Most of you do too.
Thanks again.
Gil
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In negotiations, it is always a good sign when the other side opens saying "later and maybe sooner" instead of "definitely never".
During the tour, I saw what I think is an old model midrange driver from Atlas, but marked as manufactured in Atlas's new location. This could be the replacement for the more recent EV manufactured midrange. I concluded at the time the guys in Hope are indeed working in the direction Bob G states.
I also note that the spec on the old Chorus is up to 101 dB. Therefore, Klipsh has worked with other horn tweeters pretty close in sensitivity to the K-77.
We should be happy. I predict that at worst, we're going to see the Heritage line with improved drivers.
I'm keeping the faith.
Gil
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I note a lot of the discussion about amps refers to their performance when they are being driven to near the upper limit. Usually 40 to 100 watts.
Most of our listening is being done at well below one watt. With sensitivity ratings of some Klipsch speakers, I hazard a guess most of our listening is at the milliwatt level. That is 30 dB below one watt.
If we have 104 dB sensitivity at one meter, one milliwatt gives 74 dB of sound.
Granted, listening distances are bit greater than one meter. But we do have two speakers.
In any event 10 mW is certainly a credible figure for average. If your talking about subtile sound, we're back to 1 mW, probably.
The point is, we really don't see too many specs down at 1 to 10 mW. The few I've seen sometimes show an increase in distortion.
I don't sign on the theory that all amps sound alike. I do believe the objective instrument tests are material. But I'd like to see those run at 1 to 10 mW. Then we might get some correlation.
If the 1 - 10 mW test show something bad, it would be a figure of merit.
This is the old, still valid, "What the world needs is a good 5 watt amp" lament. It is being extented to, "What we need is an amp known to be free from distortion at 5 mW."
Gil
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Those components certainly sound like a Heresy. Others on the bbs will be able to confirm. Also, others can confirm there should be a label with more information glued to the rear.
You should check the Home Audio section of the website and look at the Heresy under the Heritage collection. Compare physical dimensions.
Gil
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I certainly wouldn't dismiss the combo out of hand.
As pointed out above, it just does not appeal to people who like to tinker.
So perhaps some generous computer controlled settings should be included.
Gil
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If bass is the question, the only answer is the K-Horn.
I hear you say there is no room, etc. Still, with false corners, you could probably make it work.
Gil
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I'm not learned in the set up.
However, check that all wiring is correct as far as polarity. An out of polarity center should have less bass, but it worth checking.
My understanding is that in most HT receivers, you set the relative level and distance in a set up menu. The setting probably apply regardless of the input. But perhaps someone can comment whether this always "sticks".
The HT receivers I've tested have a set up with circulating noise. The noise goes to just right, just center, just left, just surround. What do you hear there? Is the center muddy?
It may be a situation that you have a blown treble horn in the center speaker or other defect which keeps it from working. If you can get some noise to it, try covering the horn in the center with your hand. If that doesn't muffle things, it could indicate the problem.
Gil
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A milli is 1/1,000 and the m is used. It is 10E-3 by some notation. So you have milli-henries.
A micro is 1/1,000,000 and the u is often used as a substitute for the Greek mu. That letter has a little decender hanging down from the leftmost edge. It is 10E-6. You have micro-henries.
This system is also used with capacitors. The most common unit is the microfarad. That is 10E-6 farads or 1/1,000,000. 1,000 uF would be a millifarad, but I've not see that used.
Oh. A pico-farad is 1/1,000,000,000. You see notations to pF.
Resistors have large values and another system is used (Latin?). 1,000 ohms is a kilo-ohm. 1,000,000 ohms is a mega-ohm.
Please note the system is used in other areas of science. A milliliter is 1/1000 of a liter. It also happens to be a cubic centimeter. That is a cube 1/100 meters on a side.
See, it all makes sense once you know the language.
You'll note that values are multiples of 1,000. That is called "engineering notation". You will see that as a choice of formats on some calculators.
Gil
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John and Al are right on point as always. However, let me expand a bit. (Ask an engineer what time it is, and he'll tell you how a watch works.)
"Voltage" is also called, and is a unit of, Electro Motive Force because it forces the electrons to flow. It is also called Electo Motive Potential.
Please recall problems from high school physics. If a bowling ball is 6000 feet above mean sea level above Denver, its potential energy is measured by the fact that it can fall 1000 feet to Denver at 5000 feet above mean sea level. If the same bowling ball is at 6000 feet MSL above Death Valley, it has more potential energy because Death Valley is at -200 MSL. (Excuse me if altitude numbers are a bit off.)
So, by analogy, EMP or voltage reading on a meter depends on what the probes are connected to. Following John's point, the meter probes could be connected to 1000 volts and 1001 volts. You'd see a reading of 1 volt or -1 volt depending on how it is connected.
In all this talk of relative voltage, it important to understand that there IS a universal reference voltage for us. That is the electrical voltage of the planet Earth. We take that as zero. It is not theoretical. The "ground" connection of your electrical outlet is actually connected to a metal stake or equivalent where the service comes into your house. The "neutral" connection is too.
In design of electrical components, the metal chassis is considered "ground". Even in these days of plastic housings, the circuit board and ground buses are connected to the ground prong on the power plug. Often, the speaker minus or black is connect to it too.
We have to be careful about what is called "conventional current flow". This convention is that current flows from the plus voltage to the (relative) minus voltage. In truth, the electon has a minus charge. So, electrons always flow from the lower voltage to the higher. Our "sign" convention is a bit off.
Al is describing the function of the triode (three connections) vacuum tube. This was the great invention of Lee DeForest. He created what the British call a "valve". For all the virtues of the transistor and ICs, this was monumental and made electonics what it is today. Or at least what it was in first part of last century.
As you can anticipate, the vacuum tube "valve" (or transistor in later days) does not truly "amplify" in the sense of making something small into something big. It just allows a small voltage change to control large flows of electrons which orignate from a power supply.
You start with two leads in a vacuum. One is connected to the plus (anode or plate) the other to the minus (cathode). Not much current flows because the electons are attached to the metal. However, if you heat the source of electrons, the minus side, the molecules start to jitter and the electons are not securely attached. Now, they are free to move across the vacuum to the plate.
This is analagous to doping in semiconductors which make electons "free" or able to move about.
This heating and vacuum is the effect which Tom Edison discovered. We can have flow of electons across the vacuum. Nothing gets in their way. They "see" the positive charge on the plate. Called "The Edison Effect." An early rectifier. It is a type of switch because it allows the electons to flow in only one direction. It is a magnificent invention in its own right.
DeForest put a grid in the path and arranged the power supply to give the grid a negative voltage. Now the electrons boiling off the heater don't quite "see" the positive charge of the plate and they don't flow as much.
But, suppose we can make the grid a little less and more negative. Then, the flow of electrons going to the plate is controlled. With a bit less negative voltage on the the grid, more electons flow to the plate. This is the "valve" action.
So, you can see the overall situation. The input to the tube at the grid is a change in voltage, always biased to the negative, but modulated by the input signal. As a result, there is a change of current between the heater (cathode) and the plate (anode).
By some other circutry, the much greater flow of current in the plate circuit goes to our loud speakers.
What DeForest created was now a days called a voltage controled current source.
What time is it.
Gil
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Thanks for visiting our corner of the bbs. There is a Pro-media section which is devoted to that product. You might try posting there.
Gil
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This is an interesting question.
I've never seen any report that video being routed through an HT receiver interfers with the audio.
Of course I can imagine a situation where the video source contributes to making a ground loop. Also there have been some issues with the cable feed being above ground and creating a problem in the system overall. You really have to fix the problems at the source by proper grounding techniques.
There is an overall thought that simpler is better. A nice theory, but insisting on simplicity without a known problem to remedy is a bit unnecessary, I'd think.
Others on the bbs may be able to comment on problems switched video solves or creates. E.g. the receiver may expect to use only Dolby Pro-logic when a VCR is switched through, but may expect discrete 5 channel when a DVD player is attached.
Perhaps the question is: If I find an HT receiver without video switching, has the manufacturer taken the money saved from that feature and put it into audio technology which will give me better audio.
I doubt it. In the "old days" manufacturers of equipment made equipment with few bells and whistles and focused manufacturing costs on the basics. An example was the AR turntable. It eschued all automatic features of the record changers in favor of good performance in a manual turntable.
Times and technology have changed. Probably, all technical specs of an HT receiver ramp up hand and hand with each other and with price point. If there is a problem with audio / video signal isolation, it most likely to be cured at a higher price point. Not by simplification of design.
By analogy with autos. We might like a situation where we forego the power windows and trim in favor of a better engine and suspension. However, that type of package does not seem to exist anymore in any area.
Such are my thoughts.
Gil
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Thanks for visiting. However, there is a Pro-media section of the BBS. You'll probably get a better response there.
Gil
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I guess I was trying to say, "What this country needs is a good 5 watt amp." But PWK said it first.
Gil
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I think that what you've got now is more than enough. More better bigger is not gonna hurt, though.
As I've said before, anyone who braids CAT-5 gets my respect. On the other hand, I cring when a boat load of money is spent on cable and the cash goes to suppliers which I consider hucksters.
Do spend the money on better speakers, more CD's. That's what I think.
Gil
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I agree with Phil.
You might check the ratings of your present speakers. It may be that they're less efficent. Therefore, if you have the same placement, the Klipsch speakers might be more loud.
One thing about computer speakers is that you're typically sitting very close to them. So while they might not fill a room when you're 10 feet away, the close placement works to your advantage.
We might also point out that you're driving multiple speakers. Something else which bumps up the SPLs.
Gil
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A lot of people here have favorite manufacturers. I don't take issue with that.
My thought is that an HT receiver would be a good investment for you. Then you're ready for the addition of a few more speakers.
I'm a big fan of center channel. It really is a big improvement for not a lot of money toward one additional speaker. But do consider that you'll want to make sure you can match speakers, so keep on eye on availablity.
I'd like to point out that Klipsch speakers are efficient. I have not seen people voicing complaints regarding lack of power from amps, even the HT's. So the virtures of monoblocks, big power supplies, etc., might be overstated in this application.
On the other hand, there have been ongoing complaints with low level noise from the HT receivers. I.e. hiss from the amp. It seems this comes from the digital processing circuits. It is not a power supply issue.
Therefore, in making a choice, do try to audition HT electronics for noise levels. That is more likely to be the bigger problem.
All things considered, my personal belief is that midrange HT receivers are a good value for the $100 or $200 over a two channel little brother. Naturally, you can throw all sorts of money at high end amps. But the money is better spent on speakers as long as you find an amp with low noise.
Regards,
Gil
What is the nature of the DVD output?
in Home Theater
Posted
Mike,
Thanks for your response. I'm gonna read it carefully and do some more investigation.
Regards,
Gil