@@FOH3663 A group of scientists moved a Polar bear from the North Pole, to the South, and monitored it. After a month or so the bear was acting despondent and lethargic. It was apparent to the scientist, that the bear was bi-polar.
A part of that is probably the importance we normally put on getting the positive and negative of the speakers right, so that they are not out of phase. Every connection is marked as if they were DC, although the signal is AC.
@@Douglas_Blake This "standard" is still the norm. You don't want to diminish the efficiency of your woofers/midrange speakers by reverse polarization.
For the breif break-in period (50hrs depending on the drivers) I typically run brown noise with plenty of deep bass to generate a lot of cone movement to help loosen the suspension.
@@Douglas_Blake when you only work out a woofer for a few seconds/minutes, you only temporarily loosen the suspension, just like stretching a rubber band for only a few seconds/minutes, it will revert to it's original state quite quickly. When you work out a woofer for a long period of time, the changes made are more permanent, meaning some of that original elasticity is lost. The same thing happens when you leave a rubber band stretched for a long time, it will still shrink back, but never quite to its original size/shape. It also is very dependent on the woofers in question & how stiff the suspension is. the more stiff, the more break-in it will need.
I'm not going to comment on Paul's advice. But I find it interesting that so many audiophiles have these rituals and superstitions about what to do with their gear otherwise they can't enjoy it fully. Why can't you just hook your new speakers up and start listening to your favorite music? Why do you need to play rainbow colored noise for 128.44902 hours unattended before you're ready to really evaluate them? They're gonna break-in either way, so why not be there from the beginning? And if their sound does change and it goes from garbage to glorious, don't you want to experience that first hand so you can tell us all about it, like I know you will?
I just blast them loudly with house or trance music. Pink noise ain't gonna do shit. You're just going to blow the mid and tweeter by the time you have it loud enough to get the woofers dancing nicely. I turned some up loud on a pair of Eltax bookshelf speakers I had and the woofer just moved out as if I applied a DC signal lol.
That’s interesting that you mentioned tying 2 polarized capacitors together to permit them to work in an AC circuit (such as a crossover network in my case). An electronics instructor showed me that many years ago. I needed a 12.5uF capacitor for a midrange driver. He had me tie 2 25uF caps back to back via the “minus” connections. That resulted in 12.5uF “non-polarized” capacitor. I was also told that non-polarized electrolytic capacitors are supposedly built that way internally.
Never bothered with speaker "break in" whether they be speakers in my home stereo/surround system or my guitar amp speakers. I just play music through them whenever i feel like it. Do they sound better after "break in"? Not that I have really noticed. Any change is slow and subtle. Certainly not a night and day difference.
Interestingly, my neighbors never complain about my loud stereo. In fact, I'm often complimented on the clarity of my system and my musical selections. A win win situation if ever there was one I guess ❤😂
Ever since I placed a gik diffusion/absorption panel on my rear wall I'm now able to experience the same loudness satisfaction but at a lesser volume! The room acoustics sound so much better that the perception of the music sounds a lot louder. That's a tip for whoever's got lousy neighbours. 😜
What to do is this. "I hear you knocking on my wall. Go around! You have to go around! There is no doorknob here on my side of the wall. There might be a doorknob sticking out on your side of the wall, but on my side there's nothing! It's totally flat." OR...."I can't hear anything you're saying. My stereo is turned way up."
Speaking of polarity, when it comes to subwoofers, it’s important that the positive always points the speaker cone outwards even if just using one sub. So if you hear a type of explosion, the cone moves outward and it can push air. If inverted, you won’t get that sonic impact.
I don't believe the wood effect extends into a sub reproducing pressure waves. Certainly, positive summation with the mains may be an attribute ... but as listeners, we experience the final blended response. Shaping the final response often includes manipulation of phase, time, polarity, distance and proximity. That suggests to me that absolute polarity benefits don't extend down into a sub's range. Thoughts?
@Douglas Blake Besides, as I detailed in my response, we experience the blended response, ... so to achieve positive blended summation in the listening position, anything goes with regard to manipulation; time, phase, location, etc.
It will still work the other way, but might be out of phase with the bottom end of your mid-high speakers. The explosion sound isn't a single push of the cone, but rather several cycles of cone motion.
Heres a thought. If you place them face to face clamped together they become basically one driver..(isobaric) compound loaded. When you run a tone or sweep through them and the flipped driver is reversed wired. Its not out of phase.. the drivers couple to each other and break in evenly.. after you unclamp them and do t/s parameter tests youll find they will be more closely matched. Its a common practice in high spl car audio..
The big question that puzzles me is why such a "break in" would be needed and beneficial at all? If the original mechanical characteristic is suboptimal and needs to be improved via this process, are speaker designers so clueless that they don't know about it and cannot do this in a controlled environment before the speaker set is sold? If I buy cheese, I don't want to wait for weeks to age it myself in my cellar. The other question about "break in": are those mechanical changes progressing all the time or they stop after some time? If they stop, why? If not, is the sound better and better or at some point it starts to deteriorate? In other words, how much time after speaker "break in" I have before they start "breaking down"?
Another possible way to break in faster. Do the speaker break-in in a cold environment, maybe chilly but not freezing. The spider and surrounds will be stiffer, and therefore should break some inter molecular bonds faster. If it's too cold/stiff it will damage the speaker. If it's in a warm environment, the compliance will be looser and may not break-in that much. Never tried it though, lol.
I just wonder if the signal is really going to cancel out for destructive interference, in this way. The two channel are stereo and so they can have a quite different waveform with the result of not canceling out properly. You have to play two channel mono recording.
Yes, for a stereo recording they would subtract, so you would mostly only hear the difference between the channels. How much the difference is varies wildly between diffferent recordings and different types of music.
If you don't mind separating the conductors of one channel's cable sufficiently to reach the same terminals on each of the speakers (two "positives" or two "negatives") and disconnecting the wire from the other amplifier output channel, using one of its conductors to connect between the two remaining speaker terminals, you'll automatically deliver identical signals out of phase to the two speakers, regardless of the source material. Half the power you'd otherwise get to each speaker, so if desired, nudge the volume up a little.
@@Douglas_Blake I can see how much simpler it would be for the average person in their living room to go and buy a 2 channel signal generator and learn how to use it rather than just changing how a wire is connected. Makes sense. Of course, if they have a button marked "MONO" on their amp or pre-amp, they could use the even simpler method of pressing it. 🙂
@@Douglas_Blake Yeah, I guess that reluctance is a real factor. Still, I like to put info out there in case someone comes past sometime and thinks "Oh OK, I wouldn't have thought of doing it that way."
Paul, I get the signal or wires can be flipped. But since it’s making the “flipped” sound wave do most speakers have the driver and motor send up for excursion in the primary direction. And do I g this can bottom out the driver? We used to see the surrounds get stretched in when we did this on drivers that had damage and we did not care about, I could not think of doing this to a high end good set of speakers? Maybe at low power but not at anything that is going to move the cone a lot. Thanks for the insights :)
I would also recommend him to play a mono signal to really phase out the sound when playing them against eachother. Otherwise since most songs are stereo he will phase out the common signal and play the difference between the channels..
I found an easy way to breakin especially large speakers is to use youtube and play videos from there. They have videos that run a sub 50hz heck sub 20hz tone for hours..you wont hear it but you speakers will move and work
At first I was tempted to argue for constructive interference instead of destructive cancelation. I am imagining one plate moving forward while the other moves backward - but both plates are moving in the same direction because they face opposite directions. However both plates will maintain their distance apart so there will be no compression decompression needed for sound. Cool trick.
Because one speaker is connected reverse polarity I think when they face each other they would push and pull the air, rather than cancel each other out by ?
I look at the lowest frequency each driver can play and create a file with a sine wave playing at those frequencies simultaneously. This makes the hi,mid, and low drivers play louder at their lowest frequency for better break-in due to more driver excursion. Also playing mono with drivers facing each other. You can find the lowest frequency of each driver from a spec sheet or just looking at the crossover points and lowest audible frequency for a good approximate.
Yes, but that would be true if the speakers produce the same sound - in mono signal. Stereo have some differences between sound of each speaker, so I wonder how does that reflect in this matter. Maybe I‘ll try
I've heard of this before and I guess it makes some sense but I don't think you have to play them particularly loudly to get the results you're looking for.
Is that why the foam rolled edge breaks down after 10-20 years, because I didn't break in the loudspeakers? How often should I switch speaker sides? Why aren't speaker enclosers cubed shaped to make driver rotation easier? It is a pain to remove the driver and rotate it. Should I rotate them 180 degrees or 90 degrees? How often should I rotate them? Does laying them face down or face up when not in use extend the driver's life? Facetious? Yes!
No, foam surrounds break down chemically over time being the nature of the material used. More recent materials (of quality) seem to have a longer active life.
Re; face up/face down, yes sag will be encountered ... but it's not an issue. Actually ... up-firing/down-firing sag is benign vis-à-vis front firing sag.
@@FOH3663 I did once have to reset the suspensions of a pair of 15" JBL drivers in stage floor wedges (so foldback not FOH 🙂 ), that had sagged almost to one end of travel. It took a couple of weeks with the cones bolstered outward and at 45 or 50°C before the spiders would relax back to hold central positioning long term. At least line-of-motion sag doesn't normally give you a scraping voice coil.
My neighbors don't complain about loud stereos. It's a relief actually, after hearing my lawnmower and jackhammer collection. If you had two jackhammers facing each other, would they cancel out? Would anything cancel out? I like lawn mowers a little better. They have a cable. Carver used out of phase cancellation years ago in their Sonic Holography circuit. More difference between Sonic Holography and regular stereo than between stereo and mono, said Hi Fi News & Record Review reviewer. It was amazing. The more you lived with it, the more you realized.
LOL. A lawn like that is only beaten by a weed whacker. I once rented a place that had high weeds. I must have been the most popular guy on the block with my weed whacker that day That house had a major static electricity problem. When you'd turn the light switch on you'd get a little shock. It was so bad I was thinking ghosts. Maybe a.static electricity ghosts. Static is invisible, but we know it is there. I found out the guy who passed away who used to live there worked in the sweater section of a department store, and his second job was selling balloons. Enough helium balloons would make the ultimate cable risers. Getting cables off the floor really does work. Pierre Sprey of Mapleshade Audio likens it to removing horse blankets over the front of the speakers. He was a big audio cable guy. Not someone stupid. He designed high tech fighter jets fpr the Air Force. He made his own audiophile recordings also; Mapleshade Records.
I find the idea of "breaking in" speakers and other high fidelity components to be a farce. An automobile engine has a "break in" period because of mechanical issues and tolerances. Even though speakers ARE mechanical it is not in any way related. "Burn in" for electronics is valid to detect early component failures, but this is a function at the manufacturing plant, not the home or any end user.
Good points. But break in isn't a farce, however you're right, all the discussion and the "sky us falling" obsession with the minutia is silly. Non issue.
@@FOH3663 Speakers meet specifications when they leave the factory. No "break in" period is required. However, when the customer receives the new speakers, it takes a while for his brain to adjust to the nuances of the new sound and he will perceive that they got better as he continued to listen to them.
@@swinde Again, it's a non issue. Much to do about nothing. BUT, if you've ever handled brand new LF drivers, they possess a "set" ... the suspension is a bit stiff right out of the box, it quickly goes away after some high energy excursion, perhaps a heat cycle as well.
The fact that an electrical/electronic engineer even needs to ask this question given the context, bothers me. Lost trust in colleges these days. There is no substitute for self study and curiosity.
In the absence of a mono signal, it's often not too difficult to wire the speakers in series out of phase on just one channel, then the signal passing through each is automatically identical.
I dont understand why one of them needs to be reversed. In normal conditions, a face to face speaker wouldn't cancel each other? If one has the fase changed, because they are face to face, wouldn't them be on fase again? Just asking.
No harm in asking! No, in-phase speakers facing each other will both at the same instant create a compression that wants to move away from the cabinet, followed by the opposite, a "suction" pressure reduction from both speaker cones. There's going to be a small gap between the faces of the cabinets, which will actually work rather like a compression driver. When the speakers are out of phase, when one pushes air outward, the other one is simultaneously trying to suck air inwards. They will tend to cancel each other out. The resultant sound level escaping out to be heard will be reduced.
Right, it has nothing to do with the break-in ... it's merely for convenience, to null each other's output, and lower the perceived loudness. I've been in audio since the 70's, I've only done that one time ... and that was merely a fun experiment. ~40 yrs ago, I positioned a pair of Cerwin Vega 3-ways face to face, opposite polarity. I placed moving blankets over the slight gap and let 'em rip.
@@PlatypusPerspective thank you for the explanation. So it isn't related to 'cancellation' I see, but to don't let the wave escape. When one pushes the opposite sucks.
Here's a novel approach. Just place them where they belong, wire them normally, and just listen to music without trying to split hairs until the cows come home.
Indeed, if any variance of the mechanical behavior of the speaker suspension is going to occur, it will happen naturally over time simply by using the speakers.
Face to face and one out of phase won’t cancel the sound, that will make it louder. I think you meant one speaker next to each other facing in the same direction, and one out of phase.
JD, imagine the two woofers facing one another, one moves outward compressing the air, at the same time the one opposite moves inwards rarefying the air. The woofers will just push air backwards and forwards between each other, tending to cancel any pressure variation. It doesn't operate any differently whether the speakers face each other or are facing forward side by side, except face to face they are coupled much more intimately and the time involved in travelling the distance between the drivers is greatly reduced, so the cancellation effect will occur up to much higher frequency.
A visual aid; place your hands together, palm to palm/finger to finger. Then move them as a unit side to side. Proximity is vital ... additional air between drivers results in more loss, less nulling generated.
