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Old 5th March 2013, 03:29 PM   #511
Legis is offline Legis  Finland
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Electron loops

I Tested the electron loops with 3 parallel 8" 18awg teflon cable loops attached to both phases of a bridged amplifier's output at the amplifier end. I twisted the them slightly together and tinned all ends (6pcs) with Wonder Solder to form a circle.

The load was current driven JBL 2446J compression drivers (33R in series with the drivers). No speaker level crossover is used since I use passive line level 1st order filter. The top end appeared little brighter, but I'm not sure if the effect was positive or not. The first reaction was the sound got bit more hazier. Jury is still out, have to test some more. I have to test them also with the woofers, which I did not try yet.

Basket grounding

However, grounding the woofers' baskets to minus-phase of a bridged amp made clear positive impact. Same thing also with the JBL 2446J compression drivers. I used 18awg mil spec teflon cable also in these connections. The inner resolution of mids and blackness of the background increased. Upper end appears cleaner and clearer.

Both situations result in massive basket conductor area (large electron bank?), as there are 10pcs x 8" woofers per channel and the JBL's massive compression drivers weight ~30lbs/pcs. I don't know if the mechanism of action is due electron loop/bank in the baskets, RFI shielding of the voice coil, and/or the fact that the basket now floats with the signal but it's definitely a keeper.

I measured that grounding the basket of the woofers also grounds the top plate (short circuit between the basket and the top plate) as the basket is attached with screws to the top plate. The back plate is "connected" to top plate through the ferrite ring of the motor, very high resistance between them. It's hard to ground the back plate. I would ground the aluminum phase plug of the woofers, but it would also be quite hard. With compression drivers I could ground the whole thing, other side of the ferrite to one of the screws that keep the compression chamber in place, and the other side to one of the screw threads that are used to secure the driver to a horn.

Last edited by Legis; 5th March 2013 at 03:36 PM.
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Old 6th March 2013, 03:11 AM   #512
wlowes is offline wlowes  Canada
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Legis
I am no expert in these matters. I do recall reading through the thread that it is quite possible to make the sound worse by having wrong ratio of wire to dielectric. I would encourage you to not give up before trying the loops as suggested. Very fine magnet wire. lots of it. 3 pieces of shrink wrap. If you are going full tilt, you listen, then put the slits in place in the shrink wrap and then listen. Impact to me is not dramatic. I think the word used is coherent. Seems to fit. If you overdo the shrink wrap it will have the effect of muddying the sound.
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Old 6th March 2013, 08:37 AM   #513
Legis is offline Legis  Finland
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Quote:
Originally Posted by wlowes View Post
Legis
I am no expert in these matters. I do recall reading through the thread that it is quite possible to make the sound worse by having wrong ratio of wire to dielectric. I would encourage you to not give up before trying the loops as suggested. Very fine magnet wire. lots of it. 3 pieces of shrink wrap. If you are going full tilt, you listen, then put the slits in place in the shrink wrap and then listen. Impact to me is not dramatic. I think the word used is coherent. Seems to fit. If you overdo the shrink wrap it will have the effect of muddying the sound.
Dielectric properties are also very propable cause. All dielectrics charge and discharge in slightly delayed manner compared to the conductor because of the molecular friction of the insulation, that varies between different insulation materials. Too much delay, muddy sound?

The best insulation materials store less energy (= low dielectric constant = low capacitive effect) and charge/discharge the energy faster (low molecular friction). I would presume that teflon is on top of the list (after vacuum and air) of very near. Polyester and polyurethane based thin enamel coatings, that are used to insulate the magnet wires, are propably also very good in this regard.

The heat shring however migh not be so good? Their properties at least might vary quite much (depending is the shrink polyolefin or polyethylene). I would perhaps try substituting the heat shrink with teflon tape.

Has anyone tried loops fully without any insulation (= air insulated). I wounder if the oxidation of the electron loop in such arrangement is important or not, as it does not really carry the signal. Silver oxidises quite slowly in room temperature.

Last edited by Legis; 6th March 2013 at 08:44 AM.
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Old 7th March 2013, 12:50 AM   #514
BudP is offline BudP  United States
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Yup, the dielectric constant is the main control here. I use polyolefin (DC of 2.2) rather than Teflon because it's charge and discharge threshold are less. This means that the dielectric withstand is less, but who cares here? The use of type 2 Litz wire ensures that the loops do not act as stub antennas. In the Ground Control items there are even more factors that are manipulated but for the diy parts, fine wire, preferably with insulating material coating each strand and a small amount of polypolefin works the best. Trust me, I have an amazing assortment of stuff that did not work and Teflon coated lead wire is among them. Though, if you remove the Teflon and use an inch or two of the silver clad copper wire as the connection lead, you will be surprised by the results.

Good to hear that the basket ground scheme works for you. It has for everyone who has tried it that has contacted me. There is more to be had.

Bud
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Old 7th March 2013, 07:08 PM   #515
sippy is offline sippy  United Kingdom
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Well, I read this thread right the way through in the early hours of this morning and thought 'What the heck, might as well give it a go'.
I took a length of 13amp stranded flex, ripped the conductors from the outer sheathing, chopped them into 16 inch long lengths / 4 lengths per loop, bared the ends and shoved / clamped then into the negative binding post of my EmKens.
(EmKen's being the biggest 'Ken' enclosure by Planet10, sporting Eminence Beta 12Lta)
So, it being 5am by the time every thing was hooked back up, I could only listen at Very low levels and various strange things happened, sound stage collapsed, expanded to the point that every thing sounded like it was out-side of the speakers centre line, collapse..... Interestingly, when the collapse/expand was in the middle of its extremes, things sounded, for want of better words - RIGHT!
30mis of this saw me go to bed slightly bemused.
When I finally got home, I turned on my amps psu, made a cuppa tea and started listening to music.
The collapse / expand thing happened again, but this time far more rapidly and settling down to 'normality' after 15mins or so.......
There has been a lot of 'Hold on, there are four new instruments in this track' kind of thing, one live recording a person coughs quite loudly, the sound has always been there, but not coming from behind me.
Brushed drum kits sound...... just like a brushed drum kit.
This mod is, for me, ASTOUNDING.
Next is drive unit basket grounding and doubling of grounding from amp to loudspeaker....... am going to wait a while longer before I go EnAble, for some reason I cant hear any thing in the tap test and the thought of messing up drivers that have taken 6 months to run in scares me.
Thanks BudP for this very interesting tweak
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Old 8th March 2013, 06:17 AM   #516
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Quote:
Originally Posted by sippy View Post
... am going to wait a while longer before I go EnAble, for some reason I cant hear any thing in the tap test and the thought of messing up drivers that have taken 6 months to run in scares me.
G'day sippy,

It took me two hours straight of tapping my cones before I was clearly hearing the sweep zones (where the sound of the tapping changes direction). It's easier to do this late at night when it's very quiet. Once you learn what to listen for it becomes much easier. Make sure that the drivers are out of the cabinet when doing the tap test.

You could always do some cabinet and port EnABL...

Cheers,

Alex
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Old 8th March 2013, 06:53 PM   #517
BudP is offline BudP  United States
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There are three "sectors " to a tap.

Initial strike. This is what most people hear as a tap. We are geared to pay attention to intial arrival of any sound. You can use this portion of the tap sound to locate Raleigh waves and that is all. As you tap in a radial line there will be a sector that responds noticeably more vigorous than adjacent areas. This is very likely to be a Raleigh wave, but you cannot be certain until the rest of the driver is under control. Usually you must apply a damping material, in a fairly narrow band, on the other side of the diaphragm right under this area.

Mid tone. This is useful for finding subduction zones, usually immediately adjacent to Raleigh wave zones. This zone sounds dead compared to zones before and after, no tone to speak of. A pattern set in the middle of this zone and one just as it begins are the solution. Typically one pattern set at the point where the tone goes dead is sufficient and all that will fit. In 10 inch and larger cone drivers you may end up with more patterns here.

Decay tone. Here is where you will find most of the places to apply patterns. In listening to the decay you will have to ignore the other components from this tap. As you listen to the tap decay, while taping radially along the surface, you will notice a narrow zone where the decay seems to loose direction and then change direction as you move back and forth across it. Once you can focus on just the decay portion of the tap this will become fairly obvious. A pattern set in the middle of the directionless portion will disperse this activity completely.

The end product you are looking to achieve is a smooth change in direction of decay tone. From straight out or even slightly toward the center of the voice coil, when taping next to it, to aimed off the cone, parallel to the cone angle, out at the outer edge of the diaphragm. Dome diaphragms are a bit different but you will still find the same directional switch as you tap up the side of the dome. Same rule applies for placement and the eventual decay pattern will shift from lateral at the beginning of the dome to straight out on axis at the tip. In all cases the surface of the driver will seem to be "faster" than another untreated driver of the same part number. The tap will be dispersed very quickly with no echoes.
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Old 8th March 2013, 09:49 PM   #518
sippy is offline sippy  United Kingdom
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Default Groundside Electons

Thank you for the explanation Bud, I am sure I have read this in one of the many EnAble threads..... I find those threads a bit like wading through estuary mud!
Needless to say I have saved the above reply as a word doc.

I have an update regarding the loops - In my over tired excitement I installed my crude effort in the positive side of my system........
So, I decided to double up my speakers earth returns this afternoon, realised my mistake, did the necessary corrections and OMG, all of what I first noted AND a new added smoothness, which is a huge bonus as the 12Lta can be a bit rowdy at times.
Plus even more detail
Interestingly, there was no period of settling in this time

I know I'm not hearing what I want to hear, my girlfriend and 2 visitors who have listened to my system before have commented on the 'new' sound.

Alex,
My drivers are still not flush mounted, I got sucked into listening to and not fully finishing the enclosures. On the 'to do' list is get carpenter friend to make false front baffles, then decide on a finish, make another box to contain tweeters, finish basket damping mods..........
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Old 20th November 2013, 05:56 PM   #519
50AE is offline 50AE  Bulgaria
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I got very interested in this thread.

I wonder if I can use thicker wire to try it, with good results? I have 30 AWG wire and if I have to wind 150 strands and over, it's gonna get very thick.

What about using teflon pipe strip as dielectric. I don't mean I dont have heat shrinking tubes, but their Diec. constant is inferiour to teflon.

Or I will just sit, listen and experiment.
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Old 20th November 2013, 06:21 PM   #520
BudP is offline BudP  United States
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Actually you can use fewer strands. The dielectric you add will just have less effect. I used what I happened to have on hand and since I own a transformer company, the 140 strands of #40 gauge coil winding coated style wire, twisted up into type 2 Litz configuration is what I used. Type 2 configuration specifically to avoid having the loop act as a stub antenna. To duplicate, divide the total strands into three piles and twist each pile up into a rope with approximately 1 full turn per inch. Then take all three and twist together at about one turn per 2 inches, in the same direction as each section is twisted. Not exactly correct, but good enough. Expect to be driven crazy by this activity.

In your case, using Teflon or poly-olefin should not make much difference. Both have a dielectric constant around 2.2. With the heavier gauge wire you may end up with PVC or even mylar as a preferred material. By the way, you can make a simple tube of the chosen material and slip the wire loop inside of it to test with. Slightly more refined sound with it wrapped around the individual section of cable, rather than around both sectors of the loop, but still quite useful.

By all means sit and listen, wonderful wife irritation avoidance technique, "But honey, I am doing a scientific experiment" sort of dodge.

Bud
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