Any recommendations internal speaker wire?

A considered view: AUDIOTECHNIEK - Cables and the Amplifier/Speaker Interface - OpusKlassiek

There is a good summary provided.



If you are experiencing crosstalk at your speakers the problem probably comes from your amp or its sources. Their is very little difference between speaker cables in this regard in domestic cable runs - see the above article.

Preliminary check: try different cables. If that doesn't solve the problem, here's a check method:


To check your speaker cables for crosstalk:


1. Note the position of the volume pot on your amp for your normal listening level. Turn the amp OFF.

2. Unhook cable A at the speaker and connect a resistor of similar value to the speaker, and ample rating, in its place.

3. Unhook cable B at the amp end and short the + and - wires together for SS amps or connect a 2 or 3 ohm resistor( 1 watt will do) across the + and - wires for tube amps.

4. Turn your amp ON. With music playing, and in steps, turn the volume knob up until you reach the previously noted position all the while listening to speaker B.

If the music is coming from speaker B then there is capacitive or magnetic coupling to the cables. Noticeable capacitive coupling of the speaker is very unlikely in domestic systems - see the article above. Move the cables around and see if their is any change. If there is, the problem is probably electromagnetic. Twisted wire is better in this regard.

Then repeat the above for B and A instead of A and B.

If you hear music then.

5. Connect your speakers with the shortest length cable that is feasible. If the noise remains it may well be that the amp input circuitry, or a source, is capacitively coupling to the amp output - refer to the above article.

Of course different cables can be substituted for a comparison with the existing cables. I think in the US that you can return purchased items so this would be a no-cost initial test. Unfortunately this is not so in some countries.

Quote:

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Originally Posted by mah

A considered view: AUDIOTECHNIEK - Cables and the Amplifier/Speaker Interface - OpusKlassiek

There is a good summary provided.



If you are experiencing crosstalk at your speakers the problem probably comes from your amp or its sources. Their is very little difference between speaker cables in this regard in domestic cable runs - see the above article.

Preliminary check: try different cables. If that doesn't solve the problem, here's a check method:


To check your speaker cables for crosstalk:


1. Note the position of the volume pot on your amp for your normal listening level. Turn the amp OFF.

2. Unhook cable A at the speaker and connect a resistor of similar value to the speaker, and ample rating, in its place.

3. Unhook cable B at the amp end and short the + and - wires together for SS amps or connect a 2 or 3 ohm resistor( 1 watt will do) across the + and - wires for tube amps.

4. Turn your amp ON. With music playing, and in steps, turn the volume knob up until you reach the previously noted position all the while listening to speaker B.

If the music is coming from speaker B then there is capacitive or magnetic coupling to the cables. Noticeable capacitive coupling of the speaker is very unlikely in domestic systems - see the article above. Move the cables around and see if their is any change. If there is, the problem is probably electromagnetic. Twisted wire is better in this regard.

Then repeat the above for B and A instead of A and B.

If you hear music then.

5. Connect your speakers with the shortest length cable that is feasible. If the noise remains it may well be that the amp input circuitry, or a source, is capacitively coupling to the amp output - refer to the above article.

Of course different cables can be substituted for a comparison with the existing cables. I think in the US that you can return purchased items so this would be a no-cost initial test. Unfortunately this is not so in some countries.

---

mah,

Just because a guy has an EE degree, is a professor, and has patents, and papers published, does NOT make him correct by definition in what he publishes !!

In fact, this guy is pretty sloppy in certain ways. Your own post, done with the intent of helping others, becomes a distaster, just like the other post where you " EE proved " there was no difference in AWG s needed, beyond a certain AWG, for crossover construction. LOL. What a sad joke.


This silly EE Professor, R.A. Greiner, reports sloppily and is in error. He discusses Robert Fulton, ( my first audio mentor ) and Robert's "Fulton Gold" speaker cable, and Greiner gets it ALL wrong.

Greiner says the following in writing ( and if its in writing, published, from an EE, it MUST be true )

" The third is a plastic-jacketed pair of 'welding size' conductor real welding cables. I believe - from Fulton. "

Robert was alive in 1984, Greiner could have called him and discovered what the cables really were, and how they came about!! I was Robert's Southern California Factory Representative, and I could have told EE Greiner what the cables were, to a certain degree. I did a public Audio Seminar in the early 1980s in Los Angeles, Sutro Auditorium, where Mr. Fulton came in from Minneapolis, and discussed his cables, and audio, at length, answered questions form the public, and we did a speaker demonstration.

Better for this whacky professor to get information direct from Robert, rather than write MIS information and highlight his ignorance and lack of preparation.

We don't need any theory what so ever. I can take ANY member of this Forum, and on MY ALTEC system, in my apartment, I can A-B the difference between each of my amp-to-crossover leads not touching at all, and touching in one, or maybe two spots, going to each channel. It is a 114 1/4 inch run in each case. ANY and ALL would plainly hear it !! And KNOW precisely what way to set it up, what sounds best, at least in "my" listening room, with my gear.

Oh well, your intent may be good, but your post and reference flunks, doesn't cut the mustard. Its laughable to me. Don't be discouraged, keep trying. But maybe you should be listening to things, with your ears, and post from THAT PERSPECTIVE, instead of just reading papers on line with your eyes, and believing its true ????

Jeff Medwin......Low Ohms.

Well, the professor had a pair of Fulton's cables, so after testing them he knew that they really weren't particularly special. He didn't say they were necessarily bad, either.

You disparage pretty well anything that disagrees with your view of audio based on 'I can hear it'. Well, get some credibility for your claim by submitting yourself to a COMPREHENSIVE hearing testing by the best Audiologists. Universities would love to verify your claims and it probably wouldn't cost you a penny.
"Ears into their 8th decade outperform teenagers, dogs and bats", I can just see the headline.

Post the results for us all to see. Then you could show your credibility. Unfortunately you seem more comfortable denegrating others to avoid having your claims subjected to scrutiny.


This professor has credibility. You do not. Prove him wrong. Take the test.

Quote:

---

Originally Posted by mah

Well, the professor had a pair of Fulton's cables, so after testing them he knew that they really weren't particularly special. He didn't say they were necessarily bad, either.

You disparage pretty well anything that disagrees with your view of audio based on 'I can hear it'. Well, get some credibility for your claim by submitting yourself to a COMPREHENSIVE hearing testing by the best Audiologists. Universities would love to verify your claims and it probably wouldn't cost you a penny.
"Ears in their 80th decade outperform teenagers, dogs and bats", I can just see the headline.

Post the results for us all to see. Then you could show your credibility. Unfortunately you seem more comfortable denegrating others to avoid having your claims subjected to scrutiny.


This professor has credibility. You do not. Prove him wrong. Take the test.

---

Your comments are personal attacks, rather than any thing helpful.

and in quite poor taste.

there was a troll, doing the same, @diyaudio.com.

constantly attacking one person, for the most part.

tho not exclusively.

this had gone on for years,

finally resulting in his being banned.

he was also, a moderator.


which was truly sad, as he was capable of much greater things.

Tom, I respect that you and Jeff are long time personal friends. A couple of other individuals over the years have stated on forums that they found Jeff to be good, in-person, company.

His overall on-line history is anything but what you are saying. I dearly wish that the persona you describe was generally displayed toward others on-line.

I disagree with many of Jeff's posts because they contain false or misleading information. He seldom credibly substantiates his statements and engages in obfuscation or abuse in reply. His forum record is not good in this regard. Re obsession, have you ever really considered what keeps Jeff continuing to put up the same old stuff, year after year on so many forums at every minimal opportunity, even when his opinions have been invalidated by so many people.

Don't make it personal. It's about his unsupported opinions and demonstrated intimidating behaviour toward those who disagree with him, plain and simple.

Altec is derived from All TECHNICAL Services. Guess who supports TECHNICAL and who dismisses it?



************** I SUGGEST THAT ALL WHO ARE UNHAPPY WITH MY POSTINGS REFER THE MATTER TO TODD WHITE. ***********

Quote:

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Originally Posted by mah

Guess who supports TECHNICAL and who dismisses it?

---

Talking to you is like talking to a child,

Whoms age wanders between 8, and 15.

Tom, put-downs are an admission that you can't support your opinion.

Let Jeff support his views. If you can help him support his views then discuss it with him. He is an adult and can handle replies himself.

Quote:

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Originally Posted by mah

Tom, put-downs are an admission that you can't support your opinion.

---

Yeah.

Sure.

..................

i was going to buy some graphite rods, to make some monomolecular carbon dioxidide,


might get some of that wire, instead ...


random pic -

http://www.hostboard.com/forums/hbmc.../2017/06/7.jpg

I suggest that comments not related to the OP be posted here: MAH vs LOW OHMS

I don't agree with the thread title. The issue is more to do with Jeff's misleading posts and his behaviour toward those who disagree with them. Anyhow, better here than hijacking other threads.

Post #2 states the issue in plain English.

I have to take Marshall's side on this one. Jeff pollutes many of the post on this site saying the same thing over and over. If you disagree with him, he will belittle you and tell you that you don't understand. He never offers up any creditable science or proof, just offers up his mentors who interestingly enough have never offered up any either.
I feel like I'm arguing with a close minded child when dealing with Jeff and it is getting very tiresome.
I agree with Marshall on a hearing test for Jeff. Not once has he offered up any proof beyond his hearing. If Jeff is to have any credibility than he must prove that his hearing is supernatural. And than of course we must find out why that none of this can be measured with instruments.
I know the US Navy can identify almost any ship out in the seas a half a world away from the sonic signature of the prop. Even two seemingly identical ships will have slightly different sonic signatures.
Anyway, I'm tired of posting on this board and having Jeff crap in my threads.

BillWojo

Poor mah, poor Wojo, they are coming apart at the seams !! Right before our eyes.

G-d forbid, someone mention listening to music as a "test" of equipment. Ohhh no, ya gotta have a written paper on file, even if its WRONG, but it must be published, and an EE degree is the ticket to the truth..

What the heck will a hearing test tell about listening to music reproduction in a home environment. I want to remind you all, its FAR more complex than the simplistic EEs theories would have you think!! mah, you are grasping for straws, attacking me, when you ask for a hearing test. Its hilarious, what you are, ( which I despise ) and how you act.


How can one explain that 80 year old woman on Robert Fulton's listening panel " Who couldn't hear a watch tick", say " Whats happened to the highs" when Robert Fulton removed the fuses from his "big" speaker system, which came-in from 42 KHZ on up, and extended to 80 to 110 kHZ ???????? Resultants come down into the midrange, and any good, experienced listener will KNOW whats good and what doesn't cut it !!

How old is Bill H at GPA ?? He KNOWS whats good !!

Also, If I don't have " credibility " according to mah, please consider my two audio mentors.

My first mentor, ( 1978-1988 ) Robert W. Fulton, OWNED / RAN an audio company, had one of TWO of the best rated speakers made, on the face of THIS earth, according to Stereophile's founder, J.Gordon Holt - for high end audio.

The other speaker system Gordon Holt suggested at that time was a Infinity ServoStat system, which was Arnie Nudell's company. I personally knew both these guys, Arnie was local, would buy Decca cartridges from me, and at one time or another, I ran BOTH of their speakers in my own apartment. What was mah and Wojo listening to back then, I'd love to know. What would their sound systems sound like to ME, ( not them ! ) IN their homes, today, in 2017 ???

My second Audio mentor, ( 1988-2017 ) heavily helping me in the last ten or so years, ( as I got back into ALTEC and high efficiency speakers ), is Dennis Fraker of Serious Stereo, Livingston, MT. What are HIS credentials.?? Well, I have mentioned them more than once.

In 2005 ( Stephaen Harrell, Six Moons Audio ) and in 2016 ( Stereophile Magazine, Herb Reichert) gave Dennis Fraker FABULOUS reviews for his demos those years at the big RMAF Denver audio show. Read them. They are on line.

Mr. Harrell seemingly got "into" 604s as a result of visiting Dennis' RMAF room. Read about, and see photos of Mr. Harrell's subsequent GPA / ALTEC 604 journey, here :

6moons audio reviews: Steph?n's Altec 604 Dream Speaker

And here, below, is Mr. Harrell's assesment of what he HEARD, at Dennis's room, in 2005:

6moons.com - industry features: Rocky Mountain Audio Fest 2005

Both reviewers saying ......best sounding room at the entire show, out of maybe 200 or 300 audio exhibitors in the audio business, each year.


On a very personal note, Mr. Futon played a huge role in my life. He, ( primarily by his consistent Christian conduct ), led me to eventually accept Jesus Christ. Mr Fraker, led me to having the best possible amplifier, within my means, for me to enjoy in my home hi fi. Fulton was, and Fraker is, ....a cherished friend.


***** mah and Wojo, I am NOT Mr. Fulton, and I am NOT Mr. Fraker, but I am fairly confident I am hearing about the best there exists, especially on ALTEC / GPA, or CLOSE to it, and I will always respectfully tell you and others the truth as I know it. *****

Listen up Wojo. There really IS only one best,..... it is, by definition, singular !!! Insulting you??... so sorry. That is just the way it is. I won't back down from speaking my mind.

I don't have to prove it. You two don't even really have to understand. I don't worry much, what you two attackers think.

I may make errors from time to time. But remember this .............The proof of the pudding is in the eating.

Back to the subject of this thread, the wiring information I clearly outlined in this thread, is part of the equation that " won the RMAF show" in 2016 - on GPA 604s !! Do as YOU please!! Its nice for me to get to know you all.

Have fun guys and girls, I sure do !!


Jeff Medwin

Lets get back on topic here. I'll respond to Jeff later on the other thread.

BillWojo

I wanted to update my progress. I have got the systems up and running. But I will be re-doing the wiring after studying in more depth the posts. I did the wiring before some of the posts that discuss some specifics were posted. M22579/11 16 and 18 AWG in lengths mentioned. My take on Low Ohms and GM's posts is that it would be preferable to have the speaker "internal" wiring with wires separated- not twisted- or even touching. I will study and ask for clarification.

My initial impressions:
1) I was expecting there to be weak bass because of open baffle design. (mentioned in posts on these) I am not hearing this- bass is beautiful, harmonic, ample amplitude, and "has great air". Why? Small room and placement? Firing angle about 14 degrees off wall perpendicular, baffles about 8" apart at center, placement close to wall? Can move a lot of air without clipping the 8W amps. Charlie Louvin "I'm No Longer in Your Heart"- Johnny Cash "Dark as a Dungeon" at volume is quite and experience. Well studio recorded Nashville country from the 60's is IMO some of the best recording technique- and is a good match to the 300B amps and 604's.
2) I am not gonna take a position as to recommendation- that said, I wil say that these OB's worked out way better than I thought they would.
3) I believe an advantage of OB's is lack of signature of any type of box. As name implies: "open".
4) So far somewhat of a downside is that (as with most speakers I've had), the 604's seem sound better at volume. Maybe a possible downfall of OB's. I'm reminded of the old systems that used to have "loudness contour". (Of course my hearing's not so great- 69 yrear old mechanic) One of my other speaker sets is Fostex FE168 Sigmas in Nagaoka folded horn enclosures from Madisound. The Fostex/BLH's sound better than most speakers at low volumes- and have good dispersion at angles.

I will post more specifics and photos of build for the record- and in case any one is interested. Pictures a little dificult with 95kb forum limitations. Thanks so much to all......:)

Neat work. Interesting project.

Think about the length of those short wires compared to the many yards of wire in the crossover inductors. The very very very very short lengths of connecting wire have extremely low capacitance and inductance compared to the values in the crossover.

That is why Altec used smaller size but properly current rated wire in their crossovers. Twisted or parallel or separated? Larger gauges of cable have higher C than lower gauges due to larger conductor spacing. Twisted wire is more resistant to external electromagnetic influences. At the length shown in your pic, insignificant. If there is hum or noise or crosstalk the problem is elsewhere and not due to your crossover wiring

Got tired of over thinking, decided to use Belden 9497 and be done with it.

Neat wiring.

You write " I have got the systems up and running. But I will be re-doing the wiring after studying in more depth the posts.".

Here is what I suggest, using the 8 Watt 300B amp:

Your losses are presently way too high, and your transfer efficiency is highly compromised, as wired.

Wire lengths, crossover to drivers, need to be the same, .....your tweeter looks longer than your woofer length, ....... slightly.

(1) Speaker input terminals to crossover: Use double 12 AWG Mil Spec, for each polarity, 14 1/4 inches to the crossover board. wires don't touch.

(2) Crossover to woofer, same as above, double 12 AWG for each polarity, no touch, and tie wrap each each lead to the " spoke " on the speaker basket to eliminate tugging destruction. Suggest 28 1/2 inches for your specific length, for BOTH sections of the co axial. Eliminate totally use of the stock ALTEC woofer press-to-fit connectors and CAREFULLY and QUICKLY solder directly to the terminal that holds the voice coil wire, on each polarity.

(3) Crossover to tweeter. 28 1/2 inches, M22759/11 16 AWG, single run, no-touching. I personally like to eliminate the press to fit, and solder ( quickly, carefully ) to the diaphragm. Cover woofer and driver s with clean rags, when soldering to them. Remove rags, of course. ' Sounds nicer under drive.

(4) 300B Amp to crossover. NO TOUCH and equal lengths. Use two Fulton 57 1/8th inch lengths, or three, IF really needed, of your own self-made speaker wire. Try double and / or triple 12 AWG, m22759/11 12, and CAREFULLY A-B that against Audio Research wire, after executing (1) to (3 ) above.

( I use two Fulton lengths and tripled-up Mil Spec 12 AWG m22759/11 12 on my VOTTS, with a 1.3 or a 3 Watt amp. ) Each polarity is lightly drill twisted around itself, but NO-TOUCH, one polarity to the other, amp output to drivers..

Use what sounds BEST to YOU !!!

Have fun, if you have any questions, contact me.

You will have very good wideband transfer efficiency, as I have outlined it.

Don't worry about the length of wires in your inductors, they are fixed, and you have little control over the AWG, unless you replace them. Just use the shortest possible length of the inductor's wire, as it comes OFF the winding.

Have fun HEARING this, I sure do ! Tell us about before-and-after. Nice report so far !!

Jeff Medwin.....Low Ohms.

Re-posted this photo on other thread ( MAH vs LOW OHMS ), see page 4.

Mass - Loading Speakers, for Extra Performance gains - drlowmu - High Efficiency Speaker Asylum

Quote:

---

Originally Posted by kipduff

1) I was expecting there to be weak bass because of open baffle design. (mentioned in posts on these) I am not hearing this- bass is beautiful, harmonic, ample amplitude, and "has great air". Why? Small room and placement? Firing angle about 14 degrees off wall perpendicular, baffles about 8" apart at center, placement close to wall?
4) So far somewhat of a downside is that (as with most speakers I've had), the 604's seem sound better at volume. Maybe a possible downfall of OB's. I'm reminded of the old systems that used to have "loudness contour". (Of course my hearing's not so great- 69 yrear old mechanic) One of my other speaker sets is Fostex FE168 Sigmas in Nagaoka folded horn enclosures from Madisound. The Fostex/BLH's sound better than most speakers at low volumes- and have good dispersion at angles.

---

1) All of them plus baffle design, though as a general rule the room dominates below ~250-300 Hz, so a big variable and why so much technology, etc., is devoted to studio, cinema, etc., room design.

Baffles are acoustically close too, so there's summing going on down low and the 8" gap is slot loading front to back radiation to boot. Raise them off the floor some and you may get a bit more slot loaded bass out of them.

'Great air' is lack of acoustically small box syndrome. Perch a 400 lb woman on your chest, then try to sing to get a keener understanding ;).

4)As a general rule, HE speakers need a 'loudness control' to tonally balance the speaker over its LF - lower mids bandwidth, which the 604-8K's XO tone controls are for [what the BLH does acoustically], but you don't have, so guess whatever you've got doesn't have [enough] shelving built in for OB loading. Anyway, today we call it a BSC [baffle step compensation] filter, so you can either modify yours or add a custom designed fixed or adjustable one to add in series of each speaker: General Speaker Related Articles

GM

- - - Updated - - -

Quote:

---

Originally Posted by kipduff

My take on Low Ohms and GM's posts is that it would be preferable to have the speaker "internal" wiring with wires separated- not twisted- or even touching. I will study and ask for clarification. Thanks so much to all......:)

---

You're welcome!

Then you misunderstood mine :(. In short, 'twisted' is the century + proven way to wire for minimum signal degradation.

WRT wire size, it's all about voltage drop over distance, so there's plenty of sites with all the necessary info to accurately calculate any length wire run, how much [fractions of] dB difference it will make, etc., but for 'giggles' here's a 604's period correct frame of reference........... in a late '40s - mid '50s era [based on pics of studio gear] RCA Recording Studio and Sound System Architectural and Engineering Manual, the wiring size nomograph only considers 22 ga - 14 ga wire sizes and if longer/larger is required, then run multiple 'twisted' conductors as required.

More pertinent to the 604-8K wiring in a typical HIFI/HT app [assumes a ~10% power loss over distance]:

8 ohms nominal [one half of total length required]:

22 ga = 15 ft
20 ga = 22 ft
18 ga = 38 ft
16 ga = 60 ft
14 ga = 95 ft

This was off a log-log chart, so just 'eyeballed' and could be off a foot or two on the longer runs, but it's obvious that HE speakers don't need large wire unless you want them to do double duty as frequency shaping filters as the tradeoff of less power loss over distance, which at ~10% represents an inaudible difference in dynamic headroom with HE, low power rated speakers.

Better IME to design for least signal degradation and add outboard [adjustable] filters to fine tune the system to suit one's app, hearing, etc., than relying on someone else's perception of what it's supposed to sound like.

This is based on cotton braided, rubber insulated copper wire [solid or stranded], so without checking, guessing modern insulation will allow even longer runs for a given wire size.

Notes all speaker wire runs be twisted and withstand a 600 V hi-pot test*. In a sketch they make it plain that all speaker signal wiring be twisted, so this includes XO wiring, etc., too.

Notes that signal level differential between speaker, electronics wiring is great enough that crosstalk isn't an issue, though power lines and/or multiple discrete signals can, so isolate from power cords and between bi-wiring, multi-amp wire runs.

* 'Megger' test nowadays.....something sadly lacking in DIY system builds as this 'lights up' any wiring, component 'shortcomings' in the signal chain.

GM

We do a lot of megger testing on commercial aircraft these days. Its not good enough to just check for continuity and shorts to ground with a regular DMM. We megger most of the wiring. It checks for insulation breakdown and problems to come.

The megger uses high voltage (either 500 or 1000 vdc) to test the wiring to its neighbor, or to ground. For me, anything over a few meg ohms is open. Some tasks specify a certain reading. Like over 150 meg ohms.

Hi GM,

To twist, or not to twist ??

It may be " centuries proven " as you suggest, but it is not always the best way to execute it, if one simply listens.

I have recently been able to listen to wires, twisted and untwisted, and ....in certain applications, ....untwisted sounds better to me . Two specific examples follow :

(1) In a transparent SET amplifier, the end-to end ( outside wires ) of a power transformer's high voltage secondary windings leads, going to a rectifier tube, sound best if NOT twisted. ( The 5 VCT filament winding to the rectifier tube, however, NEEDS to be twisted. ) I believe there were two people who already independently made such conclusions, Jack Elliano was first - long ago, and recently, Dennis Fraker, both Manufacturers.

(2) For between power amp to driver runs, I have recently A-Bed this, ( this month ) and on my system, polarities not touching clearly sounds better. In fact, ANYONE would plainly hear this on MY system.

Although the decades-old EE books denote what AWG works for so many feet, and I appreciate you showing this to us all..... I suggest that their assumptions may need to be questioned, re-evaluated, as being ...not adequate. It ass/u/mes a 10% loss. Is that ....a good assumption??

My first audio mentor, Robert Fulton had a saying I like a lot " An inch of bad wire can ruin the musical experience ". I agree with him, while at the SAME time, I seek to show absolutely no disrespect to you, and your MANY contributions to ALL of us !!

I would hope this Forum is " big" enough to allow some diversity of thought. Non touching of polarities, in the two areas I have mentioned herein, ( H.V. winding and amplifier-to-drivers ) were specifically ( and purposefully ) used in the RMAF demo room in 2016 by Serious Stereo, and they will be again, this October 2017.

To see a photo, taken by the Stereophile magazine reviewer, access the URL below, and look at the photo of the two monaural RED JJ 2A3-40 power amps, and VIEW how all the leads are very carefully orientated !


RMAF 2016: Sunday at the Show with Herb | Stereophile.com


I discovered the results of " no touch " in MY system, only about ten days ago, and was ecstatic over the new and positive results. I seek to share that with others. What I HEAR, always trumps any decades-old written theory. If it sounds better, it is better IMHO.

If you personally A-Bed this, and clearly heard it, what would YOU do and / or think ?? Reality trumps theory. Results matter.

Respectfully submitted,

Jeff Medwin.....Low Ohms.

Quote:

---

Originally Posted by Elitopus1

We do a lot of megger testing on commercial aircraft these days.

---

When did they slack off? Among the many diversive systems I designed, oversaw testing, installation, etc., or as part of a design team, all electrical systems I'm aware of were hi-pot, megger tested regardless of its intended app.

GM

Quote:

---

Originally Posted by GM

When did they slack off? Among the many diversive systems I designed, oversaw testing, installation, etc., or as part of a design team, all electrical systems I'm aware of were hi-pot, megger tested regardless of its intended app.

GM

---

When I first started in aviation, we didn't have that many task cards requiring the wires to be meggered. Maybe this work was done at other checks. I work at an MRO doing mostly heavy checks.

Now we have quite a few cards requiring the megger. From testing wiring to fuel pumps. The older planes get a lot more of this. And the McDonald Douglas planes get a whole lot of it. Could just be because of the aging fleet and wire insulation breaking down.

I'm sure they do a lot of testing on the new systems. I have never been involved in the manufactering of aircraft, so I don't see this part.

Quote:

---

Originally Posted by LowOhms

Hi GM,



I would hope this Forum is " big" enough to allow some diversity of thought. Non touching of polarities, in the two areas I have mentioned herein, ( H.V. winding and amplifier-to-drivers ) were specifically ( and purposefully ) used in the RMAF demo room in 2016 by Serious Stereo, and they will be again, this October 2017.

To see a photo, taken by the Stereophile magazine reviewer, access the URL below, and look at the photo of the two monaural RED JJ 2A3-40 power amps, and VIEW how all the leads are very carefully orientated !


RMAF 2016: Sunday at the Show with Herb | Stereophile.com




Jeff Medwin.....Low Ohms.

---

My work gets my brain so screwed up, it takes me a while to digest the stuff in this thread.

Yes- I see the separated black and white wires in the picture. Looks like could be the 2 x 12AWG-per-polarity (9AWG!) Mil-spec setup you described earlier in this thread.

I see what looks like a 604, rear mounted in center of baffle of "transmission line speaker". Gonna study this design- and MLTL as possible new future 604 enclosures.

- - - Updated - - -

Megger Ohm meter. I've heard of them- but never saw or used one. Understand the concept well- a weak circuit may show no resistance without a load. We have electronic liquid sensing monitors on our petrol tanker equipment that are supplied thru a circuit that runs from battery then goes down a rabbit hole in the massive wire bundles in the truck cab area for its switching and CBs. Then heads back along the frame to the truck tank monitor- and splits to the 7-way plug and back to the trailer monitor. Many opportunities for weak link. The monitors use about 0.2 amperes. If a monitor fails while loading a load of gas at the refinery, the loading process terminates, and because of sequential blending, the partially loaded product cannot be sold. In fact, my company has to pay to have it disposed. I use a spotlamp bulb (3 amps) as load at the monitor end of the power supply circuit to make the circuit fail and get the intermittent weak link to come out of hiding.:)

- - - Updated - - -

I think this open baffle setup is breaking in. Currently using Mac Mini computer streaming college FM radio stations thru iTunes (iTunes is my nemesis- but sound quality forces me to try to figure its interface out). Then USB out to tube DAC- then RCA cables direct into 300B monoblocs (no preamp- volume control in streaming program). Seems to have real good synergy.

I want to gather info, specs, and some pics of this OB build and make a small document for the forum. Am trying to learn how to use Layout program from Sketchup. Any recommendations for simple draw program? I think with some application, Sketchup layout is gonna work for me I hope.

I'm building my own crossovers for 604-8G based on the Markwart design. My current plan is to split off the speaker input to hf and lf using 20 awg silver plated solid for the hf and 12 awg stranded silver plated cu for the lf. These gauges will be used for the entire run, hf and lf, through the crossovers to the speakers. Please beat me up or approve.....

regards -- Roger

Quote:

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Originally Posted by rogerh113

I'm building my own crossovers for 604-8G based on the Markwart design. My current plan is to split off the speaker input to hf and lf using 20 awg silver plated solid for the hf and 12 awg stranded silver plated cu for the lf. These gauges will be used for the entire run, hf and lf, through the crossovers to the speakers. Please beat me up or approve.....

regards -- Roger

---

Sounds like a solid plan to me.

I used 12 awg wire, Jantzen coils, Genteq oil caps, and Dayton resistors in my Markwart 604G xover build. I ended up using fixed resistors instead of an Lpad.

J Markwart did a great job designing those crossovers! I'm sure you will like them. Post some pics after you build yours

Thanks. I also plan on a fixed resistor once the crossovers settle in. For me it is all new - will have to tune the bass port and work through the entire process. I have time, so it is a lot of fun. I've de-constructed the Altec Magnificents and resized all of the parts so they are suitable for the 604s (9+ cu ft). Starting to fabricate the baffles and cut the dados in the cabinet walls to accommodate the baffle and horizontal structural support (ala Billfort cabs) . Will post xover pics once I have done them. They should be pretty straightforward, so I am tackling the cabs first....

regards -- Roger

Quote:

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Originally Posted by rogerh113

Thanks. I also plan on a fixed resistor once the crossovers settle in. For me it is all new - will have to tune the bass port and work through the entire process. I have time, so it is a lot of fun. I've de-constructed the Altec Magnificents and resized all of the parts so they are suitable for the 604s (9+ cu ft). Starting to fabricate the baffles and cut the dados in the cabinet walls to accommodate the baffle and horizontal structural support (ala Billfort cabs) . Will post xover pics once I have done them. They should be pretty straightforward, so I am tackling the cabs first....

regards -- Roger

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Hi Roger !!

Good idea using different gauges for the tweeter and woofer. You have READ what I do, in this thread, hope it helps you some.

I have a problem with fixed resistors.

EVERYONE "knows" and will prefer them over a potentiometer or a rheostat, but there is a problem in getting the EXACT Ohmic value I want, to pad the high frequency driver, so its playing at its absolute best level in a room.

I am not sure what the best answer will be, to resolve these conflicting needs ( the sonics of " no Pot " - a nice soldered-in resistor, vs: the VERY FINE adjustment capability of a really good wirewound pot. )

On a superbly well set up ALTEC system, I am sure we all can deduce and easily hear one tenth of an Ohm of tweeter padding, and, I further feel we can adjust things to MAYBE as low as 2 /100ths of an Ohm, .... JUST SUBJECTIVELY GUESSING.

Of course, there is NO way of nailing 2 or 3 /100ths of an Ohm, with fixed resistors, UNLESS you revert to paralleling UN-LIKE and high-value Rs, which is not an optimum technique.

Part of the degradation of a Pot is the small contact area between the resistive coil, and the wiper contacting that coil, diode effects, etc.. There are other negatives, associated with a Pot, differing materials, etc.

My present personal solution, perhaps its temporary, in 2017, is to parallel TWO Ohmite " J " series 50 Watt wirewound Pots, say, 30 Ohms each pot, so I have an effective 15 ohm / 100 Watt rated pot, with double the contact area, wiper to resistive coil. I use 16 AWG M22759/11 to do the paralleling, and Wonder Solder.

Ohmite MADE hardware, to parallel two 25 Watt ( H ) or 50 Watt ( J ) pots, although its fairly costly. One COULD make a DIY coupler by visting your local ACE Hardware store, and applying their imagination. I have, with " H" pots.

I spent a couple decades of my life adjusting Fulton Premiere speakers which have a five-way tweeter, and an " H " Ohmite for EACH driver's level control. I sometimes used a cotton cue tip, to " touch-gently " the screwdriver slotted control shaft", to get the final adjustment. Boy, that would freak-out some of my audiophile friends. One can hear - or perhaps sense - this stuff if they concentrate and have a decent set up-overall. I believe its a natural and G-d given capability, we all have.

Anyhow, I am pleased with the 2017 Paralleled " J " pots, in my A7-800 DIY crossover.

Wanted to share that idea with others. Feel free to try it, and listen to that, tell me what YOU hear .

Ohh, one other thing I like, I mass load my DIY crossovers. A plywood crossover base is suspended on three Golf balls - beneath the base, held in position by three small rolls of multi-colored Electrical Tape from WalMart. On TOP of the base, I have screwed in place a triplet of wooden dowels, maybe five incheshigh and one inch in diameter. I then put 48 pounds of Patio Stepping Stones ( 3 ) on top of each crossover...... sounds better that way, at least to me, at home.

Everything is important . Have fun.

Thanks,

Low Ohms....Jeff .

What's wrong with paralleling resistors to nail a specific value? It's done all the time. I need and want a real explanation to this. You can't keep making outlandish claims without backing them up.

BillWojo

Quote:

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Originally Posted by BillWojo

What's wrong with paralleling resistors to nail a specific value? It's done all the time. I need and want a real explanation to this. You can't keep making outlandish claims without backing them up.

BillWojo

---

Hi Bill,

I'll explain it as best as I can. In the highest of high-end audio, the best builders will tell you, unequal valued paralleled resistors produce SKEWS to the signal, and the music.

I THINK the MFA Luminescense was built with paralleled plate resistors, equally matched value resistors. In its time, it was considered the best possible PHONO preamp on the market!! I have also seen EE Thorsten Loesch post schematics making extensive use of paralleled, equal resistors. Best to just use two Rs, less chance of skewing than with 3 or 4 !!

It is FINE to parallel resistors, IF the resistor values are the same value, but NEVER different values in parallel Bill.

When paralleling two Rs of the same value that MEASURE within 1 % of each other, you earn a "C+" . If you can parallel two that measure within one tenth of one percent of each other, you have earned an " A ".

In my SET implementations, I will parallel TWO resistors, matched, whenever possible.

In Greg's new Type 46 SET amp for his Valencias, I ordered ten Roderstein MK-8 ( 2 Watt ) resistors, which I believe are 1% parts, from Percy, 549 K Ohm as I recall. I was able to harvest two pairs, closely matched ( Fluke 8060A ) out of the ten pieces. But I GOT two - HIGH QUALITY - and great-sounding 274.5K Ohm plate resistors.... for Greg to ENJOY.

Two resistors, when paralleled properly, on a tube's plate and cathode, IS literally " State of the Art " in tube SET implementation.

The better, most experienced SET builders will know and always do this. But the Rs must be closely matched to avoid skews. Greg's amp is sounding NICE to my ears. Am having Johnnie Cash's 21 year plus touring sound man, come by tomorrow, for him to give a listen to my VOTTS. He'll critique me..... honestly. Larry..... aka..... L.J.


This implementation, as I am describing it to you, done for Greg, gives TWO equal paths for the signal to develop in the plate resistor, and since both Rs are CLOSELY MATCHED, there is NO adverse signal SKEWING when paralleling.

Its only dropping 170 VDC across the plate resistor, at 0.0007 A. for ONE section of a 12AX7. So Bill, its only dissipating 0.119 Watts, and it has a four Watt ( 2 Xs 2W. ) rating. That offers circuit stability and beneficially, has PLENTY of resistor lead wire in the path, to maintain SUPERB transfer function.

I routinely do the same procedure, on the cathode of the Driver tube. for maximum sound quality. Everything matters.

There... 'ya got it Bill.

Best wishes,

Jeff Medwin.....Low Ohms.

Jeff. What nonsense. You are making this forum a laughing-stock.

Jeff, you still haven't backed up your claim, do me a favor and take this over to DIYaudio and try and sell it there. Oh, that's right, you got thrown off of that board for this nonsense.
Your explanations don't explain a thing, they are just more outlandish claims.
Skew problems because of parallel resistors? Go ahead and try that over at the EEVBlog forum. Let's see how far you get there.

BillWojo

One of the things that makes me quite passionate about drag racing is that it is mathematically pure in fairly simple terms. Reality is measured precisely by the clock, and low ET rules, no excuses, no horseshit, no influence by the subjective artistry of individual interpretation. What used to work, still works and will always work, bound by fundamentals. Audio is not that much different.

Thank you bowtie, as someone who hangs out at a race shop I know exactly what your saying. A nice improvement on the flow bench can be calculated to real horse power gains and that can be calculated to the expected change in a car or motorcycles ET. It's pure math and physics.
No where have I seen the amount of BS fly as in audio. I worry about the new members that haven't been around long enough to separate fact from fiction. Is the beginning of there learning curve built on a solid foundation or is it built on sand?
This forum has been going over the top lately and a lot of mis-information is being spread as the Gospel truth. I'm pretty disgusted with it all. The one place on the internet that is all Altec and it's being destroyed by a virus.

BillWojo

There is two things wrong here with these series of posts, very wrong ...........


(1) All THREE of you fellas, Wojo, mah, and Bowtie, are residing in a bubble....all three have NEVER ever heard the type of execution, and ALTEC system I speak of. SO, you three posters have ZERO actual direct experience to judge these results I speak of.

(2) The subjects I discuss, ( wire, paralleled resistors ) are intelligently employed, and get consistent recognition, since 2005, by reviewers who attend RMAF shows. Listeners occasionally suggest they are hearing "The Best Sound at the SHOW " among several hundreds of audio exhibitors.. Certain years are better than others, BTW, due to a lack of set up time.

I have pointed out the RMAF reviews for folks to read. S. Harrell ( Six Moons, 2005 ) and H. Reichert ( Stereophile Magazine, 2016 ) are but two great examples that come to mind, off the top of my head. URLs were given by me, earlier in this thread, on Page 6, Posts 51 and 60.

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

"The proof of the pudding, is IN the eating ",

or,

to put in Bowtie language, a drag racer : Its

" where the rubber meets the road".

I rest-my-case with these above consistent, published, multiple public-domain proofs, spanning over a decade in time.



Discovering the truth is always interesting to me.

Some can't handle it.

Many are destined, never to find it !!

Some eventually find it, " in the twinkle of an eye."


Jeff Medwin

I have always thought of Altec users as down to earth. As someone has told me, Altec is the working man's WE.
Usually the "magic" talk comes from the very high end audio users. People that spend 100k or more on a system. They can afford 10k speaker wire etc, and say they can hear the minute differences. To me they are just trying to justify the expense.

Dont get me wrong, I don't think its all snake oil. I think using silver coated copper can net a very very very very very small gain. But to say something like that drastically improves the system, is not the case for me. I know my ears are not that good. And I would say most of our ears are pretty "normal". Especially considering our other hobbies (I also have a SBC and run open headers:)).

I think when you hang out with all the high end audio guys you start to talk about, and believe in all this "magic".
I don't. And I would say most of us here don't. We are down to earth Altec users who are doing what sounds good to us.
There is no one good system that sounds good to everyone. They are all personalized to our own tastes.

I promised myself i would only offer constructive input, and i'm going to keep my promise.

This is probably a good point to remember what the primary purpose of the forum is about.

I'm not trying to get on the soap box here, i think everyone in this thread offers worthwhile sentiments, and Jeff brings a long needed venture into the truly high end capabilities of some of the Altec product. That said, i would urge you, Jeff, to try to understand that the true high end level of audio resolution is simply not practical or the primary interest for every Altec enthusiast. Some folks will get there, if they're not driven off the path somewhere along the way. They should be allowed to find their way naturally, and not have the "high end" imposed on them like some kind of edict.

Every enthusiast with enough interest to join the forum and participate,no matter their level of knowledge and experience, whether it be to ask a question, share helpful information, or offer high end tweaks deserves a certain degree of respect.

The contents of this forum are a reflection of all of us. I've tried to install a few tweaks on my own posting habits. I hope maybe a couple others will scratch a similar itch. ;)

Hi bowtie,

Nice post. I THINK I understand where you are coming from.

"They should be allowed to find their way naturally, and not have the "high end" imposed on them like some kind of edict."

I am not imposing my will on others, I am pointing out what " I " find works out good on ALTEC. People do not have to follow this, or even read my posts.

It appears, already one person has actually TRIED these written wiring suggestions, and seems to be pleased with his results. That would be Ron SSS, in Post number 37, Page 4, of this thread.

There should be room on this Forum, for people to discuss ALTEC, not just in a middle-of-the-road way - where most reside, but also at higher levels, or lower levels, realizing different people have differing expectations of what makes them happy in this hobby.


No need, or purpose served, mah and Wojo, to attack the Messenger !! As an example, Elitopus1 and I disagree on many things, but we treat each other with respect, understanding of the other person, and we avoid confrontation. We belittle ourselves, when we belittle other people. Forum readers can discern this.


Jeff Medwin

Come on Jeff, you made a pretty outlandish statement about paralleling resistors and you have not given us one bit of evidence to prove it. Lot's of bluster about some audio shows and such but something as revolutionary as "skewing" in paralleled resistors should be easily measured.
I have at my disposal a HP 3456A Digital Voltmeter that can measure down to 100 micro-ohms and up to 1 gigaohm. Please show me the scientific research supporting "skewing" so I can try and measure it myself.
A quick search has yielded that the long held mathematical model of resistors in parallel has held up quite nicely even after all these years. Seems that only you are trying to refute the mathematical model and only because "you" can hear the difference.
Jeff, please look up Psychoacoustics. I truly believe that it will answer most of the reasons you hear improvements after doing a lot of your "tweaks". Key word is a "lot", as you have brought up some interesting things in the past. Things like room treatments and such. Those do have scientific credence and can be measured.
So again, I'm waiting on the evidence of "skewing".

BillWojo

Quote:

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Originally Posted by BillWojo

Come on Jeff, you made a pretty outlandish statement about paralleling resistors and you have not given us one bit of evidence to prove it. Lot's of bluster about some audio shows and such but something as revolutionary as "skewing" in paralleled resistors should be easily measured.
I have at my disposal a HP 3456A Digital Voltmeter that can measure down to 100 micro-ohms and up to 1 gigaohm. Please show me the scientific research supporting "skewing" so I can try and measure it myself.
A quick search has yielded that the long held mathematical model of resistors in parallel has held up quite nicely even after all these years. Seems that only you are trying to refute the mathematical model and only because "you" can hear the difference.
Jeff, please look up Psychoacoustics. I truly believe that it will answer most of the reasons you hear improvements after doing a lot of your "tweaks". Key word is a "lot", as you have brought up some interesting things in the past. Things like room treatments and such. Those do have scientific credence and can be measured.
So again, I'm waiting on the evidence of "skewing".

BillWojo

---

Hi Bill,

THERE IS NO PROOF i KNOW OF, OTHER THAN DOING THE WORK, AND BUILDING A GOOD CIRCUIT BOTH WAYS, AND LISTENING TO THE RESULTS. .

Its logic. Its just like you can not parallel two triodes, and have them play as pure as ONE triode.

The Rs HAVE to match within one tenth of an ohm, or better, or you will get different signals through each R, and when combined, and it becomes a simple SKEWED signal .

Common sense should enable a person to understand this. If you don't " accept " what I report as being valid, for whatever reason, that is perfectly OK with me, but your entire stance IS out of the realm of common sense.

One possibility is to experiment with the plate resistor of the first 12AX7 stage in your McIntosh tube amp, and YOU decide. I'd order MK-3 Roederteies from Percy, very reasonable, and use your super meter, to match a couple pairs out of two dozen. Let us know how you do !!

Have Fun. Regards,

Jeff Medwin

Jeff, Repeated nonsense, ad nauseam. No valid explanation.

"If you can't explain it simply, you don't understand it enough"! Albert Einstein.