An Edifying Journey ...

[fas42]

Interesting one ... I have an el cheapo disk of Chuck Berry hits; that I haven't played for years and years. Well, huge acoustic, on the tracks! Remarkable, something I don't recall particularly noticing before - must check out if he favoured recording in a location that gave great space to his sound, at some time ...

[fas42]

It's getting closer to there being a turning point in my method of improving these speakers - up to now, my aim has been to get the most out of them without touching a screw; that is, diving inside the cabinets. That was based on the idea that the internal engineering was "good enough" to achieve competent sound, provided the external environment was sufficiently 'conditioned' ... however, I may have got to the end of that particular piece of string ...

 

In what way? Well, I've mentioned that there is a stabilising period when starting from cold - the upside is, after that, that they are more 'revealing'; the downside is that they then show "deeper problems" - and I've mentioned in several posts here that at the end of the day, depending upon what I play with, that there is definitely something that still needs work.

 

And this is starting to look like it's inside - specifically, the mains on/off switch. Not 100% convinced of this - and will try another round of tests today to better convince myself of this. Why should it be a problem? Well, it's a "link in the chain" - and the weakest one is that which is the most important, no matter how unlikely it is, at first blush ... it's a primitive, metal to metal contact inside the part, and contact noise could be rearing its ugly head - just a bit too much.

[fas42]

This is a track on an album which I am using to diagnose, today - gives an excellent idea of a type of recording that is very useful for pinpointing SQ variances ...

 

 

[fas42]

Well, learning a bit more 🙃 ...

 

Bev was pushing to hear "The Phantom of the Opera" - this one,

 

 

Uh, oh ... not good - decidedly constipated ... small box stuff ... Bev pretty disappointed - but kept it running. Long story short, by the end of the 2nd disk all cylinders were firing ... glorious, huge sound!

 

So, what was going on? ... Well, I had warmed the setup combo, as usual, by running through several disks, up to then - but this had been at quite low volume - phone calls had to be made, etc. But this period, and type, of conditioning wasn't enough for the speakers - the DVD player of course couldn't care less ... and it showed! Like all speakers I've come across, they need to be hammered to come to life - a combination of the electronics being forced to work hard, and the driver suspensions stabilised, by being driven to near their limits - having 2 CDs worth of music pumping out did the job ... you could literally hear as the SQ steadily improved, and got 'bigger', as it progressed through the sides.

 

I hadn't really appreciated how significant this factor was, up to now, for the Edifiers - so, a good rule ... don't write off any speakers until they have been given full throttle, for a couple of albums - only then might you get a sense of how good they can be ... 😉.

[fas42]

Right, did a variation of the warming up process yesterday, to confirm the behaviour ... powered up the DVD player only, and played through 3 CDs, while the Edifiers were off. Then switched the speakers on, and put on, at a solid volume,

 

 

Driving sound, with big acoustics ... at the start, rather dead treble, but very forward - like a high quality PA rig standard - just like I noted in a post some pages ago. Then, as it wended though the tracks this started to stabilise; size kept growing, the presentation moved back and upwards, and the treble became correct. By halfway through, this was in a very acceptable state - and huge stadium sound was happening; there was very little to complain about by the end of the disk.

 

Next CD was

 

 

and although there were some issues with PRaT, and sense of the beat, it was still of a very good order. Ran out of opportunities to check refinement beyond this point...

 

Which says what? Well, that the active speakers in themselves only really need hard driving for about a 1/2 CD length to be of decent SQ - and will do a perfectly acceptable job after this point. So, either changing the source unit, or running it beforehand for a decent length of time; or inserting an optical buffer between the player and speakers are ways of improving the time taken to get to close to optimum sound - the last method is probably the smartest, because that will give one more options for conditioning the optical waveform, to perfectly suit the needs of the speaker's optical receiver.

[GregWormald]

I'm not surprised. My car needs to warm up to function at its best too.

 

The off switch on my preamp is designed to turn off the inputs and leave the rest of the circuits on. The manufacturer states that it takes hours for the temperature of the components to stabilise otherwise. He also said it took about an hour for the amp to sound its best. That's when the output stages reached 60°C and the fan started. (I went to active speakers later and the designer/manufacturer of them says the internal amps go on standby when there's no signal present with just enough current to keep them warm.)

 

If the speaker cones themselves are majorly dependent on the surrounds to provide the suspension (unlike an acoustic suspension from the air in a sealed box) then that surround may also need a warm up to meet its optimum performance.

[fas42]

But can you tell the difference ... ? 😉

 

Yes, there will always be a warm up time - but we want it as short as possible ... leaving circuitry in standby may or may not help, depending upon everything - dynamic drivers pretty well will always need to be conditioned, to overcome what is called stiction. Which is why heavy driving gets them in the right zone, sooner rather than later.

 

In one sense the integrity of the setup needs to be higher than nominally is necessary - to act as a quality 'buffer'. It doesn't gain one that much more when fully warmed; but helps to compensate for those parts of the rig which are not fully firing from cold, to some degree.

[fas42]

Quite pleased ... did a good job unravelling this track - the bass drum drumming on this can be quite disconcerting, seeming not to mesh with the other instruments; but the acoustics of each mix element nicely presented - and allowed it to flow ...

 

 

[fas42]

On 4/24/2021 at 9:39 AM, fas42 said:

It's getting closer to there being a turning point in my method of improving these speakers - up to now, my aim has been to get the most out of them without touching a screw; that is, diving inside the cabinets. That was based on the idea that the internal engineering was "good enough" to achieve competent sound, provided the external environment was sufficiently 'conditioned' ... however, I may have got to the end of that particular piece of string ...

 

 

On 4/24/2021 at 9:39 AM, fas42 said:

And this is starting to look like it's inside - specifically, the mains on/off switch. Not 100% convinced of this - and will try another round of tests today to better convince myself of this. Why should it be a problem? Well, it's a "link in the chain" - and the weakest one is that which is the most important, no matter how unlikely it is, at first blush ... it's a primitive, metal to metal contact inside the part, and contact noise could be rearing its ugly head - just a bit too much.

 

Well, unfortunately, this seems to be the case ... yesterday at the end of a solid day of running the SQ had gone off enough to be quite disturbing - as usual, resetting the electronics by cycling the power got it back to a good state - but this is not a satisfactory method! I was fighting this behaviour 35 years ago - and, the industry still doesn't engineer good solutions for this, 🙄.

 

So, inside the box I shall go ... first round will be a crude bypass of the switch, to see if that alone solves the issue. If it does, I might explore other methods of snubbing or attenuating the contact noise, so that the switch is still functional ...

[fas42]

Stiiill not certain whether it's the switch per se, or a build up of static from the drivers working, say - why I'm quibbling about this is that the restoration of the SQ is not fully consistent when I try various methods of power cycling ... could it be that my touching the speakers to do the switching is managing to discharge some static buildup, depending upon exactly what I touch, etc? So, another round of trials today, to try variations on how I do the power cycling ...

 

BTW, I'm using this track to get the FB,

 

 

Revved up to stadium loud - note this is not the 2016 remaster, but rather the 1997 one; which has far more echo, etc - makes it very obvious what the status of replay is like, 🙂.

[fas42]

And, another issue ... not happy this morning - what's different, what's different?!! ... Uh, oh, the washing machine, a recent model with all electronic controls, was running ... and, indeed this was the problem. Confirmed by plugging in some surge busters, and a resistive load through  them, in the adjacent socket - didn't want to interrupt the cycle ... going back and forth between plugged in, and unplugged made it very clear it was the culprit. When the machine had finished, and was unplugged - everything back to normal ...

 

So what? Well, I was hoping my filtering to date was enough - and I had removed one element of that already, because similar experiments had shown it was degrading the sound ... but this made it obvious that I wasn't there yet, 🙂. Now, the end goal is to make the filtering bullet proof, so that no matter how much nasty noise is around, it won't affect the SQ - so another thinkin' session is in order; to plan the next move to make the isolation mechanisms closer to 100% effective.

[fas42]

Yesterday, because Bev has a big thing for Elvis, I put on a 31 track CD of his No. 1's - and hit the accelerator, hard. Not perfect of course, but was pounding the house quite decently - what it did point out was that I need to sort out the bass side of the things, yet again - a first for me, on a rig! On some tracks the throbbing of the bass line was resonating through the whole house - and some people want a subwoofer on top of it, as well ?? My God !! ... 🙄

 

The trouble is, that I never really stabilised the speakers as well as I aim for, in spite of me knowing how I should do it - and this is biting me in the bum, now. The mass weighting is not really as effective as it should be, because the vibrations are not being transferred to the floor structure properly - there is not a clean line from the corners of the cabinet through to the actual hard structure of the floor board, etc.

 

Will I fix this, now? Maybe, maybe not ... will think about adjusting it a bit, as a workaround; and consider a more effective long term strategy over coming weeks. It's really only a problem on certain tracks, when the level is pushed right up - other fruit is still lower hanging, so I will focus on that, in the short term, 😉.

[fas42]

Been awhile since I played this,

 

 

( Remember when curves like that were the go, 🙂... ? )

 

And it wasn't what it could be ... hmmm ... ... on impulse, checked one of the mains filter 'boxes' for the speakers side of things ... . Right, some things were touching where they shouldn't - has been a while since I looked more closely at how everything was organised, inside. Adjusted the obvious bits that were less than optimal - fired it up, again ... ah, much better!

 

At the moment it's edging so very close to the behaviour of the speaker drivers disappearing completely, even right next to and in front of one - it gets a solid tick, 🙂.

[fas42]

A step forward, a step back - still not holding up SQ over the course of many hours ... a major round of fidding, fiddling, fiddling; and not getting any clear signs as to what was causing the degradation, this time.

 

Finally, tried running the DVD player, and speakers from completely different mains house circuits ... ah, hah!! Confirmed by going back and forth - so, what does this mean? Most likely, that in spite of the electrical separation already in place, that the player supply current draw is interfering with the speaker's, or less likely, the other way around.

 

Right, need to have a good think about this - and consider a sensible next step to try, in reorganising, and enhancing,  the filtering already in place ...

[fas42]

Well, pretty chuffed at the moment 🤗 ...

 

It's been clear for a bit that there was a bottleneck in the SQ, and I was trying a few things, as noted down in recent posts ... but there were no clear answers, so far. But that's changed ...

 

I have two mains filters circuits in two boxes, one in each power supply lead combo to each component. These were done a long time ago, and were just put into simple, light metal boxes, for safety, etc - never intended to be a permanent part of a setup. They have lids which can be taken off, simple push on fit. And I experimented recently with having the lids on and off; but other factors were in play, and I didn't get good feedback as to the value of doing this.

 

But I just tried this again, making sure the lids were completely out of the equation ... bingo! That was the magic ingredient - SQ jumped up to an excellent plateau; and it retained those qualities as the tracks progressed.

 

Why? Mainly, I believe, because they were not forming a clear-cut part of the electrical environment - one lid was earthed, the other not; but the integrity of that lid structure was not good enough for the job ... a good example, yet again, of how everything should always be questioned - most likely some static noise was being generated, which did the damage.

 

A permanent solution would have all this very solidly implemented, of course - the trouble with prototyping is that if what you try is not done well enough, then you'll get poor answers. Which is what makes evolving a rig a slow and tiresome process at times - you have to be so very careful that you are really testing what you think you are testing, 😉.

[fas42]

Having another go at trying to identify exactly how appliances at a distance are degrading SQ - is it RF, or is it conducted noise? To do this, created a long extension cord for the fridge, which got plugged into the socket closest to the mains fuse box. Ah, hah ... comparing this to the normal plugging in of that appliance showed that the noise was effectively eliminated, by this long, direct route to the mains feed. How about a halfway house? ... That is, using the long extension again, but plugging into the normal fridge socket - okay, better than no extension; but not as good as the extension feeding off close to the outside utility box.

 

Which means, that RF directly from the appliance is not the issue - rather, that using distance to attenuate the noise waveform, on the mains conductors through the house, is still the simple method of solving this. The interesting thing is that 'nastier' electronic devices, adjacent to the audio setup, are not a major problem - so far, no clear rules as to how all this should be managed has emerged - very much, plug 'n' play experiments are giving the useful answers.

 

How should this be addressed? Not sure ... will have to go away and think about all a bit more, 🙂.

 

 

[MarkusBarkus]

5 hours ago, fas42 said:

Not sure ... will have to go away and think about all a bit more

...take all the time you need. Don't rush. Lemme know if you need me to turn off my fridge too. 😉

[fas42]

On a sensible note, obviously distance always works - otherwise, all the noise making electricals of all your neighbours would create such havoc that your SQ would always be a mess. As an extreme example, plug a heavy duty arc welder into the socket next to that used for your audio rig, and rev it up - will your setup shrug it off as if nothing was going on, 🙂 ... . Okay, next step - your next door neighbour does use such a device, in his work shed - for many hours in the day ... could this be causing an issue for your SQ?

 

Of course audiophiles regularly comment on how their systems sound better late at night, when everyone had gone to sleep, and stuff is turned off - but that can't mean anything useful, can it now? 😉

 

On a plus side, I was using full scale orchestral recordings yesterday, at very close to max volume, for doing this checking - this made it trivially obvious when the SQ faltered - but when it was running clean, the tremendous power and vitality of an orchestra in full cry was there in all its glory - the speakers get a big tick for doing this solidly.

[fas42]

One thing I haven't done as yet, is to explore what shifting the filtering being used in the very, very long mains leads to the components does - will moving the parts right up to the start of the conductors, at the wall socket, change anything? In particular, will it improve the isolation against items like the fridge, and washing machine, as mentioned earlier? I also have some other bits of filtering constructions, not as yet tried, which may help - or hinder ... to be explored in the next few days ...

[fas42]

Right, first run - I didn't actually alter the amount of filtering used; but moved one piece to a different point in the mains power chain ... messy business, because everything is in a prototype state - I always find it hilarious when people say, just swap between the two setup states, and run a DBT - yeeaaahhh, right ... 🙄.

 

First impressions ... good!! No sign of degradation because of appliances still plugged in - I couldn't pick an issue with the SQ ... will do another round tomorrow, when everything has "settled in" a bit better; and see if this initial result still holds.

[fas42]

Always a good sign 🙂 ... Bev came in, and said in so many words, "I'm so privileged to hear this ... when music sounds this good you can't stay in a down state; your spirits are lifted, for the rest of the day ... "

 

🤪

[fas42]

But it couldn't last 🤨 ... yes, the fridge is still having an effect - takes some time after the system stabilises to hear this ... so, more trialing required, to try and get this under control.

 

The symptoms? I have a cheapy CD of very old recordings of famous tenors, taken straight from 78's material - with interference not in the picture these sound strong, even sweet, in tone; when the interference kicks in, a slightly uncomfortable edge, a stridency around the forceful male voice is so apparent - the difference between enjoying the piece, versus merely "putting up with it" ...

[fas42]

What to do? Well, there was one filter in the chain, effectively an isolation transformer, which was always on the ToDo list to have its characteristics improved - by adding some caps. So, did this - and nominally nothing was lost - and it appeared that the rejection of the fridge noise was now much more effective.

 

But, and a big But - there was still this loss of SQ after running for many hours; resetting by pulling the plug on the speakers, and reinserting, did not help - right, now the on/off switch on the speakers themselves ... Yes!! That was the culprit - as suspected above.

 

Finally, it was time to break into the cabinet - well secured on the back by plenty of screws, pulled off the mounting plate of the electronics - some nice touches inside, the cables were surrounded by damping foam; which made my job of having them better supported far less necessary. And why that mains switch was a weakness was clear - quite a long cable from that part to the power supply proper; which meant that it could exhibit some antenna properties; especially if the contacting surfaces weren't maintaining ideal very low resistance qualities.

 

Next step is to work out best way to add reversible hardwiring to that part of the circuit - to confirm the behaviour ... tight to work in, don't want to disturb things any more than I need to - leave til tomorrow, to examine more carefully.

[fas42]

Part way through the exercise - and then I spent a day or so on car issues 🙂 ... hopefully tomorrow will see this hardwiring completed - and the cables in the area stabilised somewhat better than before.

[fas42]

Well, that was a very long tomorrow, wasn't it ... 😃? Too much happening, in everything else; finally did, a very messy, soldering link - awkward to get to, had to crouch in an unpleasant position to do it - but it should be good enough to tell me the story. Now, to tidy up, stabilise everything, screw it back in - and see what I get ... 🙂.

 

If this was something that I did for a unit that was meant to be sent off, and look after itself, I would do a far better job - but this is prototyping ideas; so a rough and ready arrangement should be enough to give me good feedback.