Using a Variac on speakers - a quiet idea

[rooster]

Tom - Hmm, Jim's last post confuses me. I asked him about the Celestion EVH speaker and he comes back with news on the EV12L and EV12S. ....And odder still, he is talking about some kind of light dope on the EVM recone from Orange County. ?? Eh, Jim's a busy guy.

So Tom, you have my thoughts on the EV12L already. I would love to hear Jim's thoughts on it, and its FBI potential. Particularily how it improves from out of the box vs. FBI.

I would also like to hear his comments about the Celestion EVH speaker. What I have to report to anyone listening is that - after running it for 12 hours at 1OVDC, it actually did loosen up just a little bit from stock (based on feel and applying a 9 volt batt across the terminals - and visually comparing it to another one that is stock). That said, that stock speaker is loose as a goose compared to most speakers. Which is to say: Wow, how does Celestion do this, and why can't my Webers be like this? I really don't see much reason in keeping it on the Variac at this point, its done, IMO, and I probably didn't need to go 12 hours.

...And moving on to my Weber ceramic BDs, all I can say is I have 36 hours on a 50 watter at 12.5 volts and it is still pretty much as stiff as it was stock. Can you say 'rock'? Very hard to motivate this speaker, and it has light dope. On the other hand, the 30 watt version with very very light dope, as finally let go enough to give it a go...

[Scumback Speakers]

rooster, edited my previous post.

Structo, I have an EVM 12S and 12L here, both reconed by OCSR. I haven't even gotten them hooked up yet, I've been way too busy. So I can't tell you about the FBI/variac thing, or what to expect...sorry. I plan on getting to it as soon as work slows down (not that it's been doing that for months, but I can dream, can't I?) a bit.

[rooster]

Jim - No worries. As to the EVH speakers being bright, yes, in a word they are. But not ice pick bright, more 'clarity' bright if that translates. Um, like lacking mid range. Compared to the ceramic BD, for example, there is a huge difference. The BD is heavy in midrange and also has a quicker breakup as a result I think. The EVH will reproduce midrange if you increase the amp's midrange control, but it doesn't seem to be as centered there as the BD. Does this relate to your take on it?

Well, I will heed your words and continue the process tomorrow. I appreciate the info. Thanks. Oh, one more question or two? When you say I can 'over volt' these by 20%, and then you relate the story about the very hot magnet, how much overvolting did you go to make that happen? I can run these 16 ohm speakers, Webers and EVHs, at 12.5VAC for 12 hours continuous and the mags are not even warm. Frankly, I think 14VAC would still leave them cool. Would a volt or two really bring on the heat? Could it be that my polarity reverse process is keeping the mags cooler? Thanks, Jim.

[Scumback Speakers]

rooster, I am safe with my speakers running at 1/2 power, but I only advise 1/3rd (as per Ted's recommendations) to make sure you're safe with other speaker maker's designs.

I'd imagine the Weber built speakers of their own models can run safely at 1/2 power, too. Just take the chart I have and multiple the voltage by 1.5, and you're there.

Since I have a 4x12 ISO cab going now, the mere idea of turning it up to that level, and the hum it would create is scary. I have my 4x12 ISO cab in a separate bedroom, door closed, A/C on, ceiling fan running...your situation my allow you more voltage, only your neighbors will know for sure.

I'm not going to bag on the Heritage models, but my results were that they needed lots of break in, and since I don't feel I'm done with that, I'm not sure what I'm going to get. They were brighter...your clarity in the upper mids could be my "it's just below ice pick in the ear". We all hear things differently, or at least somewhat as tone is subjective.

Let us know what you come up with when you're done.

[rooster]

Again, good info and thank you. I have settled for 14VAC on the EVHs. And there is a very slight warmness to the mag cover after 4 hours or so, but never hot. Checking my math, I understand your voltage settings and now understand why your mags get hot. I will stick with 14 VAC I think and see what happens for now. Man, I would love to try 17 or so but I am not that brave. Eh, but I might get a bit more daring as time drags on...

I have by now also taken a better look at the cone edge and I see what you mean, Jim. It doesn't look like much but its signifcant. My new course of action is to continue with the Variac hours, but also add some UV time outdoors, in hopes of aging the doping material even further. Yeah, crazy idea maybe but I am beginning to think that 25 years of aging would do these speakers a service.

And yes, unlike you, I am in these speakers for the long haul. So I will drag this post back to life next Thursday, post my Variac and sunlight time and tell you what I ended up with. Have a good week.....

[Scumback Speakers]

I'm taking four out and putting four more in the ISO cab now. Then I'm leaving!

What I've noticed for hum levels.

A) The higher the voltage, more hum level (duh!).
B) A 65w M (35 oz) magnet setting is the same volume as a 30w H (50 oz) setting.
C) 65w H75's and Scumnicos will rattle you something fierce. 100w models require earplugs in any magnet size.
D) My XH (80 oz) magnets require leaving the place and apologizing to your neighbors in advance, and perhaps giving them some beer and ear plugs.
E) I long for a garage and a second 4x12 ISO cab to keep up with the FBI requests for speaker orders.

[rooster]

Ha! Yeah, I appreciate your volume levels. ...But hey? Have you even tried the reverse polarity thing? You could run 8 speakers at a time, sitting on the floor and with at least 1/3 of the hum level. No need to mount them either, I just put four 2" strips of 1/4 rubber spacer material around the bottom speaker and then drop the top speaker onto it. At 14VAC the top EVH will just sit there all day with no movement.

Getting back to your sonic example, the ISO cab, I have the pair of EVHs sitting on the floor as a pair (14VAC), and then I thought , oh hey, I'll just parallel this loaded cab while I'm at it. Wow, the loaded cab shook the house - there was no way I could run them at 14VAC. So I'll just unload the cab and do that instead. Which is to say that at higher voltages my suggested method can run quieter and you don't need to load a cab - a win/win.

Too, electrically, a parallel load mirrors the same voltage so the 5A Variac I have could easily do 4 pairs of these speakers, all @ 14VAC. Do me a favor and try the big mag Scumbacks you were talking about, the loud ones, the way I have suggested? Really Jim, I know we all get stuck in our ways but you need to check this out. Your wife might come home even, the dog will stick around, the dishes will stop rattling - man, it will be like a whole new world for you. Oh, we have some sunlight today so my EVHs are getting a two hour suntan right now... Its like owning a Pet Rock.

[rooster]

OK, my break in time is over. And it might be hard to put all the hours together, considering the stops and starts at the different voltages I went through before arriving at the 14VAC number. Trying to put it all together then, I would say my finished time is 30 hours on 14VAC. And then there's the 6 hours of sunlight - maybe worth considering.

I was wasting my time at the 8 - 11 volts I had been using, that's the main discovery I made. This low a voltage is like throwing sticks at a granite monolith - worthless. I realize, too that Jim is presenting some great help but being careful that his info doesn't destroy a speaker that cannot deal with higher voltages. Which is a good way to be I think, I can't fault him for that. But, hey, if you have the brass, and are willing to be accountable to your own decisions, then at least consider that you need to REALLY move these cones and spiders to break them in. And for me, 14VAC seems to be the number.

OK, Jim said he has put over 90 hours on the Heritage Celestions that he has. Hm, my 30 hours vs. his 90 seems really out of balance. I don't know what to say about this. I can tell you this, and I think this is worth a consideration, after 30 hours at 14VAC, the cones will actually pulse height-wise BEYOND the cork surround. Which means that if you ran the felt that Glen uses, you would be slapping it on occasion. (No, I did not say 'spanking' it). Eh, but anyway, I ask you then, how much more could you ask of a speaker to be considered broken in? At this point I decided my speakers were done.

I loaded them into my two different speaker cabs that I have that I tried them in before and played them. (My 4/12 is waiting for two Weber recones). These are both slightly open back cabs, one is a two twelve, the other a 2/10 1/12 combo cab. Well, I am doing some sound samples for the LaMar PPIMV this week so I will use the 2/12 for this first hand. I am just in love with both cabs. What they have is the clarity of the Celestion, just like they had before they were broken in, but it is not as edgy and the md/bass is just warm and comfortable now. I have 'cut' but it is more musical now, rich in compressed sparkle. Well, you will hear what I mean. I couldn't be happier.

Jim, thank you for ALL the help here and your sharing of your methods! I know you are in the business of selling a product, but you are also a devoted Tone Freak that has no boundaries! Thank You!!!

[Scumback Speakers]

rooster, you're welcome. It's quite possible to move/bounce the cones up to the cork level and beyond, I've done it with a home stereo running at about 25w.

Ted Weber told me you want to get the cones moving 1/8 to 3/16" when doing this with a stereo, less with the variac since it was constant. I think the real test is heating up the coils, making the suspension and cone move to get all the parts exercised properly. I guess you could relate it to working out at the gym and using the proper weights without overdoing it.

In any event, glad to hear you like your Celes better now. Keep in mind, though, that I probably have earlier versions of these speakers than you do, and as we all know "specifications subject to change without notice" is a hallmark of Celestion products. Maybe they improved some stuff, which IMO it did need. But that's all subjective anyway. If you're happy with them, good.

[Scumback Speakers]

rooster, I tried the wiring with alternating the pos & neg wires between each speaker in the 4 x12 ISO cab. It DOES cut down the volume to about 2/3rd of what it is with them wired in parallel without reversing the pos/neg wires.

So you were right in that it cuts down the volume a good bit.

Sadly, FBI service is so popular now that 24 of my last 28 speakers ordered specified FBI treatment, so I've had to get a 2nd 4x12 ISO cab from my cab guy to handle the FBI orders.

Even now I have the 1x12 Dead Room ISO cab with one speaker in it, and the 4x12 is full of 100w M75's.

I tested it on four speakers yesterday, by the way, and the break in still worked on them with no ill effects. Just make sure you set your voltages correctly and you're good to go with this setup.

I won't be staying here long listening to all that, but thanks for the tip on reversing the leads to cut the volume...it works!

[kec]

Why not just use a waveform generator and an amplifier? That's what I do. I set the frequency to a low setting so I get cone movement (maybe an 1/8" or so for a 12"). You get very little noise (if any at all), depending where you set the frequency and waveform pattern.

The amp can be anything - I used a cheap-o amp that came with a tactile transducer (shaker for home theaters).

[Scumback Speakers]

You could probably do that, but with this method I can break in 8 speakers at once in two 4x12 ISO cabs. No matter how you wire it, with the equivalent of 20-35w (1/3rd the power handling) going through the speakers, its still going to be louder than most want to deal with.

I have to do this six days per week now, so getting the 2nd 4x12 cab will (hopefully) cut it down to 3.

[Plexified]

thanks for this information everyone . I had some webers I had blown up cause I smelled the burning too late . So breaking the recones in was an awesome accolade to all of your help .

I was wondering if Jim had thought about just reversing the polarity on the 4x12 with the same input . Here the two cabs would be out of phase and maybe reduce the noise a bit .

Jim your speakers are amazing and the heart you put into your work is really something I can appreciate . Not only in the end tone result , cause a few cabs I heard recently really were outstanding . But to help us out so much with all the mind numbing research and of course the break in is killer . And to offer it as ready to ship product is simply the END ALL . Really , I know what it must take and you simply have the most extensive approach and the most genuine concern for the end result ... TONE . Thanks everyone for your help !!

[Scumback Speakers]

"I was wondering if Jim had thought about just reversing the polarity on the 4x12 with the same input . Here the two cabs would be out of phase and maybe reduce the noise a bit . "

Nope, never considered it before I had so many to break in. I'm doing five per day until my 2nd 4x12 ISO cab gets here, and the reverse polarity wiring only works in the same cab, not separately (tried that already!).

Glad my posts/etc have helped you in some way, too. Thanks for the kind words.

[Scumback Speakers]

Follow up post on the reverse polarity wiring when breaking in on a variac. While it's true that the sound level is less with the reversed wiring (every other speaker), for some reason it doesn't seem to exercise the speaker as hard as when the wires are run in phase, or non reversed.

Based on trying this for a couple of months now, it seems the spider and cone are better flexed/exercised when wired in phase. Go figure.

So I'm going to keep them that way from now on. For those of you doing this at home, though, the easy thing to do is to swap the wiring every 4 hours or so until you get to the 16-20 hour mark so that they get flexed both ways.