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Professor Thump

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Posts posted by Professor Thump

  1. You are correct that there is a capacitor in the crossover network and this will limit your ability to check polarity with the battery test. Also since the center channel has two woofers the crossover network might be slightly different (again we'll check with the engineer) and might affect a pulsed signal differently enough to confuse the receiver.

    If the entire speaker is reverse polarity, swapping the speaker wires will fix it. If the just the woofer or tweeter was wired out of phase then it won't.

    Ah yes... I forgot about the cap on the woofer even. I am not use to designing such small speakers. Well... unless they are real small and go in your ear.

  2. There are two terms I want to clarify. Phase is the reference of one time signature vs another. We usually think of phase in terms of sign wave signals normally because it is easier to describe. Sign waves cycle 360 degrees of angle. At 180 degrees the two signals are opposite and cancel. This term would be considered Out Of Polarity (OOP) at 180 degrees.

    It is the Labor Day weekend so I am out of the office but there are two scenarios that I can think of.

    1. The tweeter is out of Polarity. This is some times the case in two way designs because this tends to allow the crossover to mesh more smoothly in the frequency response, especially if there is a single pole filter on one driver in the system. What most people don't realize is that the phase usually revolves several if not MANY cycles from 20-20 kHz. The tweeter might be out of polarity but it is In Phase. If your receiver is correlating phase at a higher frequency such as 3 kHz it will define the speaker to be OOP.

    2. The woofer or the center speaker system is out of phase. This could be an error in the assembly of the speaker. You can fix the system buy wiring the speaker out of phase. If you disconnect the center speaker cable from the receiver and connect a AA battery to the speaker cable the woofer should move out, away from the cabinet. We normally use a 9V battery but that may be too large for the woofer and burn the coil. If the woofer does move out the polarity is correct for this speaker.

    Do the vocals (dialog) sound good when playing via the center? If so it may be okay.

    Monday I can check to see what the design intent was. (I didn't design this system)

    ...On a side note. When the manufacturer is checking phase they are usually incorrectly stating what they are checking. Normally they are inferring Polarity instead of Phase. It all depends on the reference signal and how they test.

    If you have two speakers the same distance from you and you are checking phase, if you move one speaker back 6 inches while checking with a 1 kHz tone you have moved the correlative phase between the speakers 180 degrees. The speakers are canceling the tone on axis, so the only sound you hear is indirect reflections in the room.

    Do the vocals (dialog) sound good when playing via the center? If so it may be okay.

    If the image is center then the polarity is In Polarity. If the image is skewed and to the sides of the room (phantom image) the polarity is Out Of Polarity or Reversed Polarity.

    I hope this helps.

  3. Tubes are looking for two things. A place to plug in and a working voltage. Charactoristics beyond that are similar. I know you guys will argue over the sound but in general terms of electronic requirements...

    You must have the same plug config for the replacement tube to go into the socket. There are only several sizes. Pentode is popular.

    The bias voltage must be in the working range of the tube. If it runs too cold (low voltage) you won't utilize proper headroom and it will clip early. If it runs too hot the tube wears out prematurely or just pops a grid wire. For 2 channel audio (Hi Fi) a nice low watt tube amp with low cost tubes and a Klipsch speaker is a great value combo.

  4. We picked up two Glock C26's today for both of use to carry concealed. We had shot one in our gun class and each of us loved it (even though we were told not to get Glockas by a friend - bad advice). I bought one and my wife had said last week that she wanted an airweight snub-nosed S&W 38. She already has a Taurus 85 snub nose. She read up on the Glock online and warmed up to an automatic, and she really liked shooting our instructors gun. When she saw mine today she wanted to order one right there. Another customer next to us was picking up his C26 and realized that he meant to order a C27 40mm. So we were able to walk out with his and hers C26 9mm's.

    One interesting thing about the 26 sub-compact, I though that I was going to need an extended magazine or a Pierce finger extension for it to feel right. We bough two C19 15 round magazines to go with them and it does feel like a good sized handle, but honestly, the short handle and curling my pinky under the handle actually feels pretty good. It does not feel unatural at all. I am going to get used to shooting it both ways and then carry the standard 10 round magazine for concealed because it is a nice compact size.

    A guy on Youtube with a bunch of Glocks said that he liked the standard magazine and after handling the gun more I'd say that I agree. I'll need to shoot it to see if that holds up.

    There were lots of Glock for sale for $325 each + Colts tax. They were Marion county Sheriff sales.

    http://ingunowners.com/forums/ingo_at_the_indy_1500/50710-cool_and_or_unusual_finds_or_deals.html

  5. I think they are not so much forgotten as no one knows their individual stories. I  had an Uncle in World War II who would not talk about the war. I learned from my father that he was a paratrooper in the Battle Of the Bulge. And over his 4 or 5 year hitch in Europe he received 6 Purple Hearts. It seems that the men and women who have had to actually pull the triggar and take away a life are very quiet about it. It must be a very soul searching experience. I am very awed by their heroism. 

    Wrinkles

    I think you are right. Some of the vets of WWII are just now talking to get their story out while they can. Your uncle was probably from the 101st or 82nd if he jumped into the Bulge.

  6. Professor Thump was just seeing if anyone was paying attention out there in forum land. There are many things that need discussed but will not be a part of this forum. This place is for toys and not for serious issues that get people heated. And you Canadians can stick it in your ear!...[bs] Headphones that is... Can you feel the luv Dollar? [H]

    Note to self...make headphone smiley to replace the [bs]

  7. Indy had the 1500 Gun Show again at the fairgrounds this weekend. I went with Kerry Friday after work. There were lots of toys for sale. Ammo prices are high but there is more availibility.

    I bought 357 brass (last two bags) and 2400 powder along with a CCW holster for the XD9sc. I also lusted over many 1911 Kimbers and Springfields. There was a used XD45 that could have been bought with $450. All I needed was a push and I would have bought one of them. My wife would have been less than pleased if I did. But as the news unfolds she will come around.

    Win,

    I can see why you like the Kimbers. There is an attention to detail that just can't be ignored. There are also many models which make it confusing. So I can see why this may be a life long pursuit. I am also trying to understand the ergonomics of carrying a 1911. IWB backside is my target goal for CCW. Can it carry well with the regular length barrel or do I need a shorter variety VS the reliability of this shorter spring? That is the big question. Sorry for the code but it keeps the looky lews at bay. :)

    How bout those Yankees? or the comi czars? Of course I am referring to baseball and Russia...

    BTW... I just got a Lee 4 die press and loaded my first box of 357's Yahoo...Cheap Ammo! I still need a Crimp die for the 357 cal because I bought a 3 hole die earlier thinking that was what I was going to buy. Unique powder seems to measure low with the recommendation of using the .66 charge cylinder for 6 grains but I am told the 2400 is easier to measure. I stepped the cylinder up to a .71 which got me to 5.8 grns charge on Unique. I hope that is okay. They are going to go through my Dan Wesson which is well built so I am not concerned.

    Everyone still with me?

  8. Thanks for the Kudos!!! This year has just been good for the garden for us. We have thusfar, 35 kilos Potatoes, 4 Kilos Beans, 10 Kilos Onions, 15 - 20 Kilo Carrots, 5 Kilo Red Asparagus, Cherries, Apples, Pears, peas, broccoli, 3 types of Peperoni (2 of em really burn the britches) and tons of herbs. life is good!!

    Prof. Have you tried Tomatoe fleece?? Even on cold days they stay warm and ripen up really fast!!

    Here is what we have been eating 3 times a week..

    Nice spread of garden delights Germerikan! I have not heard of the tomatoe fleece. Is this like a blanket? Sometimes a plastic tarp is laid ove the plants to prevent frost damage. This is similar to a greenhouse. Maybe that is what I will build.

  9. Keep and eye on my blog in the next couple of weeks. I just got a peek at the goodies for sale from the Hope. Vintage vintage (30 + 30 years old) Tube amps, Radio's, Klipsch Needles, Compression Drivers and more! I have got to go through some of it to make sure it works so this will take some time.

    Pictures are coming...Stay tuned!

  10. You are all going to laugh and I am a little embarrassed to admit but i got my first Red Tomato off the garden this week. I planted about 2 wks too late...TOO BUSY THIS YEAR or just getting old. I have 7 plants that are up to my armpits with big green tomatoes. This weather has been cold this year. I fear the frost will come soon also so this won't have been a good year for maters. :(

    Back to hydroponic cardboard tomatoes by November I suspect.

  11. WIn,

    If I get down your way I will definately take you up on a dove hunt. I imagine the lead is quite a bit farther than on a goose and the yardage estimate even more confusing. I might need to borrow a 20 ga. since I haven't had one in a while but I imagine you may know someone who has an extra. [^o)]

    I bet doves fry up nice in the pan!

    P Thump

  12. Hi mancpg,

    The X5 is a superior headphone for accurate response...Hi SPL...Low THD! Does it sound like Klipsch? [:)]

    As far as imaging this will probably differ between users. Part of this is the geometry of your ear canal and the distance inserted into the canal. I suspect you will find that the S4 will have wider imaging. This is the nature of the beast.

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