KELSCI's ELECTRONICS AND HOME THEATER NOTATIONS

Name:
Location: Florida

see interests, AGE 63-2010 CONTACT: kelscientific@hotmail.com

Tuesday, August 31, 2010

THREE WAY MID LEFT-TWEETER RIGHT OVER WOOFER(MLTROW



















A Radio Shack MLTROW pair of speakers.
A Pair of Yamha MLTROW pair of speakers(silver bass cone)

















A pair of klh 900 b MLTROW speakers.( I own a pair of these units)
I have only one fault with these units pictured. The tweeter is too far right. For these speakers to work properly, the center of the midrange should be in line with the middle of the radius of the left side of the bass speaker. This is so. However, the middle of the tweeter is to far to the right of the middle of the radius of the bass speaker. However, the 900bs' do play adequately.

THE D'APPOLITO SPEAKER




























-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
This is a group of D'Appolito speakers. They can be used as bookshelves for the left and right main channels horizontally and for a center channel, vertically.
----------------------------------------------------------------
The top speaker to the left features a 5 way design which includes two midranges,two woofers and a tweeter. The company,Definitive Technology created a design I had conceived myself as a center channel.
-------------------------------------------------------------------------------------------------------------------------------
Recently, I made a discovery in a Optimus center channel
speaker in its wiring versus the Garrard units I possess and
some time ago possessing Koss M80 dynamite speakers. The Garrard used two 12 ohm speakers wired in PARALLEL giving an impedance of 6 ohms. The Koss had two 8 ohm speakers wired in PARALLEL giving 4 ohms. The Optimus and a Klh that I possess had two 4 ohm speakers wired in SERIES. My preliminary test of the Optimus and KLH seemed to throw a complete 5.1 speaker system into a MISPHASED circuit. I need to retest this speaker along with my others and switch the phase of the subwoofer to 180 degrees and see what happens.
-------------------------------------------------------------------------
Below is a piece of info from JIL subwoofers about subs being wired in series and the result from it. I am not quite sure what they mean other than this was the only piece of literature I could find on series wired speakers on the net.
-----------------------------------------------------------------------
IF I FIND AFTER THE TEST THAT I MENTIONED THAT
THE 5.1 SYSTEM REMAINS MISPHASED, I WILL WRITE A
NOTE ON ANY HOME THEATER FORUMS I BELONG TOO.
THE REASON WOULD BE THAT IF I AM CORRECT ON
WHAT I SAY, THEN IT IS POSSIBLE THAT MANY HOME THEATERS ARE NOT WORKING PROPERLY BECAUSE THEIR CENTER CHANNELS USE LOW IMPEDANCE WOOFERS WIRED IN SERIES INSTEAD OF HIGHER IMPEDANCE WOOFERS WIRED IN PARALLEL.
---------------------------------------------------------------------------
It is far less desirable to make subwoofer to subwoofer connections in series. Because of slight and unavoidable differences between speakers and because of the high likelihood of uneven loading between different speakers in a car, there will be slight differences in the mechanical behavior of the two speakers in series. These differences in movement result in induced voltage (called back EMF) being created by the speakers across the series connection. This effect causes a problem when two speakers which >behave differently are connected in series because the speakers can modulate each other (cause each other to move), resulting in distortion. The problem becomes more serious as more speakers are >connected in series. A good experiment to show the effect of back EMF is the following: >connect four speakers in series and short the positive and negative input leads of the series circuit. Push down on one cone with your >hand; you will notice that the three other speakers will move in the >opposite direction of the one you are pushing. Now, reconnect the >speakers in parallel, short the inputs and push down on one cone. The speakers will not modulate each other because each one is shorted directly.

Labels: , , ,

THE TOW SPEAKER----Tweeter above the Woofer








----------------------------------------------------------------------------------------
The TOW speaker is one of the most common of all designs used for stereo or home theater. I definetaly recommend its use for 5.1 systems; the main left and right and surround left and right comprimising this design. Some systems use this design as a center channel speaker although I recommend the D'Appolito design for that purpose. I prefer the woofer to be 4 to 5 l/2 inches in diameter though there are speaker systems offering three to three and one half inch designs. IMHO, those might be too small but I would need to test a group to see their performance. There are TOW speakers with larger woofers available with the most preferred at 6 l/2 inch diameter woofer.

Labels: , , ,

DIGITAL IS DIGITAL-BAH HUMBUG

Anybody who says this in relationship to cables,dvd-r software and other things offhand that I cannot think of this minute is off their rocker.

I have had software issues transferring videos to dvd-r in my Samsung dvd recorder. The best looking disc was an offbrand, but had glitches that lost data and froze video info at spots. I used a Comp Usa 4x dvd-R. It worked with good color but the video was noisy. I had a 16X Sony-that was good; also the same for a Ritedata 8x blank. I have a stack of HP 16X blanks which gave me no glitches but I did not like the video results in playback.

I have also found coax cables to vary in their sound quality in carrying the digital data from a dvd player to a receiver. The best cable was a plain vanilla cable bought for a few bucks at a store and delivered sound to my receiver.What I think occurs is that the make-up of the wire or in other words the chemical mixture that makes up the wire can effect the ones and zeroes on the digital data providing a "signature" that could be favorable or unfavorable to the digital reproduction of that data being carried to your receiver.

I have also heard diffeneces in speaker wire as well. Since I fool with 18 gauge wire(I am not going into the reason) at times I found that when I had different brands on hand that some worked better than others on certain applications. It's all trial and error, folks. Wire can make a system sound like crap regardless of the name or brand if it just doesn't do what it is supposed to do in carrying those electrons properly and adds a crappy "signature" to those electrons.

What I described above is not too different then going to the store and looking at a digital broadcast of a tv show on say 5 40 inch high-def televisions and seeing differences in their picture quality between the 5 sets because each set has its own way of displaying a picture and processing video.

Labels: , ,

SNELL CENTER CHANNEL SPEAKER


Expensive except for those who have the bread. What bothers me is the horizontal D'Appolito center of this speaker. I wish that part of the speaker was mounted vertically(W-M-T-M-W) Although I was never able to do a speaker experiment of the kind, it was my opinion that the ideal center channel speaker would be one like the Snell with a complete vertical mount. I have seen some main left and right horizontally standing speakers built that way(W-M-T-M-W) but personally I am not a lover of the D'Appolito design in any form as horizontal main speakers, but as a center channel vertical design, the D'Appolito is made to order in the handling of dialogue and center channel audio material. At this time however, I have only played with the W-T-W versions. However, it should be noted that there are two types of these speakers out there. One is a system with two woofers of either 16 or 12 ohms wired in parallel or two-4ohm speakers wired in series. Unfortunately, when you buy center channel speakers, you do not know what wired version you are getting. I have experimented with both forms and believe me, you want the former and not the latter.

Labels: ,

THE FIIO E3 HEADPHONE AMP-MARVELOUS




---------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------
If you have a set of headphones, they can be used to listen to movies and music privately. I found that my HD-TV's audio while adequate would only reproduce stereo tracks if they were unusually good. This is due to the speaker setup in the unit; they are very oval and while reproducing mono sound very well, stereo imaging is a come see-come saa affair.

On top of that, dialogue was somewhat muffled at times from movies. Making the set louder was not always the answer. The clincher was that I had to contend with my brother's HD-TV in the next room that has no door to close.

I had no room to hook up a receiver that had a headphone jack. I have only one spare unit that works on a remote control and it is buried under two recievers and a NAD amplifier so I am not about to fool around with that and wiring since I am not up to it. The answer to me was some kind of headphone amplifier.

Exploring on e-bay brought up a host of possiblities. One Chinese company is FIIO that makes a model E3 and E5 headphone amplifier. I bought the E3 because even though it had no volume control, my headphones do have vol. controls on each side. In addition, my television's audio output is VARIABLE, meaning it is controlled by the set's volume control so this little thingy was something I thought would work. It actually had good audio specs and runs on 1AAA battery. It is about the size of two matchbooks.

I hooked it up to the variable audio outputs of my HD-TV. I then went channel surfing to see what I would hear.

First the sound quality of this thing is amazing and has a built in bass boost. I listened to come current 5.1 channel movies on some of the pay stations. Of course the movie track is combined into 2.0 stereo. The sound was outrageous, nice bass and stereo imaging and sonic nuances that I would never believe were in these movie soundtracks. As a subsitute for a full 5.1 system this was quite good and rather awesome.

I also hit the Fox movie channel which was showing the 1958 movie,THE FLY. Oh I saw it in 1958 and thought then and today it is a superb horror film. Looking over statistics on IMDB.COM, the movie was recorded in 4 track stereo. At that time(1958) TV had become so overwheminly convenient to watch that the movie studios had farted around with 3-D and stereo sound. Well over my headset, THE FLY sounded great in stereo and was very well recorded for its time. Sounds jumped from one ear to the other and inbetween with great fidelity.

The 2nd oldie I listened to was the last 45 minutes of John Wayne's 1960 THE ALAMO. Though not quite as good as THE FLY, it was way way above any which way I have ever heard this movie. I had listened previously to both movies over the speakers of my HD-TV and I could not tell if there was any stereo imaging or not. I have only tapped what I want to listen to in pure stereo.

If you have an amplifier or receiver, you just plug the audio outputs of your tv set into those two thingies and use a headset that has a plug that fits into a reciever's headphone output though I have to admit the FIIO produces some amazing sound over and above many receivers that I have listened to with headphones over the years.

Labels: , ,

THE MYGICA VIDEO GRABBER
























































This device will grab video and audio information from the A/V outputs of a vcr or Laserdisc player and convert it into a mpeg 2 video file playable on a dvd player. I do have a Samsung dvd recorder which has worked quite well but I never transferred a laserdisc picture onto that machine, only using this Mygica for that onto my computer and making a playable dvd. I believe the audio is recorded at 246 kb/sec; it sounds great and dynamic on the dvd-r. The picture quality is fairly good grabbed but again it could be better on a standalone dvd recorder.

Labels: , ,

THE RADIO SHACK STEREO MICROPHONE





----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

I bought this particular stereo mic in 1986 and I still own two of the three units that I used to shoot vhs stereo sound videos in Panasonic and RCA units. Even on the linear stereo portable Panasonics and their clones from other manufacturers, I recorded phenomenal "broadcast quality" sound. Unlike many built in mics, thi s unit could record musical instruments with finesse. I also used these mics on vhs hi-fi units as well. I did get matrix surround effects with the mics too. I should have done more experimenting with the stereo pattern of the two mic heads perhaps opening them up wider but I recently examined some recordings that I transferred to a dvd-r and was very pleased with the result.
This mic was of the carotoid variety but still picked up sounds from its back thus giving some surround matrix effects. Some mics are so unidirectional that you will only get frontal stereo with no back surround effects.
This microphone might be able to be used on digital point and shoot cameras that have a microphone input and record in stereo sound.
I did try two omnidrectional microphones at that time. I thought I was going to get some enormous stereo imaging but that was not the case. In fact it seems that the mic must be a caratoid type to accomplish stereo imaging.

Labels: , , ,

A center channel tow in a unique design


When it comes to center channel speakers, some systems use a TOW(tweeter over woofer) set-up of a speaker that is the same as the satellites meaning their height is greater than their width.
In this case we have a TOW speaker center channel set-up where the width of the speaker is greater than the height so it is a vertical type system. The dialogue being reproduced by the speaker is reproduced over the width of this cabinet much like the tweeter-woofer-tweeter setup whose speaker cabinets are width greater than height.
The question to my mind is whether the above shown system can work as effectively or perhaps better than tweeter-woofer-tweeter systems. It might.

Labels:

AMPLIFIERS THAT I OWNED IN THE PAST










































































-----------------------------------------------------------------------

-----------------------------------------------------------------------

The SA-1000 sounded much like a dynaco. Nice 20watt per channel amp


The stereo 70 poweramp from dynaco delivered marvelous controlled sound quality but quite different sounding than fisher.


The pas 3x was the matching pre-amp to the stereo 70. I liked the fact it had a loudness control.


The NAD 3240pe is a strange amp from Nad. I really did not like its performance although I did get it to play very well using a speaker wire harness on an experiment. Not recommended


The Fisher had an X100 A and C. I like the sound of the X100a better; it had the tradional Fisher tube sound that I liked.


The SCA=80Q was a composite of many of the pat 4 and stereo 80 power amp. Quality control was poor because you could get two diff. amps that would sound so different. If you got a good one, you were lucky.









Labels: , , , , , , ,

AUDIO EQUIPMENT THAT I AM FAMILAR WITH







































































































______________________________________________________________________
____________________________________________________________________
The AR turntable was a cheap transcription table that gave great sound because it had a very strong base. The headshell was flimsy so care had to be exercised mounting the cartridge.
The only qualm I had with the Dynaco Pat 4 was that the same units from the company could sound very different. When one worked right, you had the finest solid state sound quality to push their power amps. It had a loudness control which I liked. The most signficant circuit was the phono circuit that could take out wow and rumble while leaving the soundstage intact with proper bass. I know of no other pre-amp,amp that could do this. There was extra circuitry built onto the phono section to do this.
The stereo 120 Dynaco power amp was a ferocious sound producer. My brother had them on ess heil air motion speakers with the pat 4. While Dynaco solid state sound sounded very "solid state" there was no question to its rigourous control of music notes or perhaps a stupendous square wave response.
The Empire Commode speakers were my favorites of the 1960s. They were wonderful on good tube equipment.
Nad 7100 receiver was IMHO about the best they ever made. It has marvelous sound quality. One model did come with a remote.
The Nad 7240 Pe was one of the worst sounding receivers Nad made. It was a 3240 PE amp with a Nad tuner on one chassis.
NHT super two towers was the best speaker I had seen since the Empire's that I dicussed earlier. The unit had a TOW 6 l/2 inch woofer and a tweeter. It had a downfiring 6l/2 inch subwoofer. The best tower with a small footprint I ever heard.
The Sansui QX 4500 quad receiver was a mixed bag. It sounded terrible on my Marantz Imperial 6g speakers but played great on some 3 way 12 inch fishers.
The problem with the unit was to get to hear 4 channel sound with SQ records. The fault was not the reciever but the advocation of same size speakers in the rear channels. If one used smaller bookshelf speakers, I think this unit and all the others would have worked fairly well, though IMHO the Dynaquad system could give rear separation in the surrounds.

Labels: ,