Variac for breaking in speakers

[amplifiednation]

I've been selling some speakers as part of custom cab orders. I've been looking into break in methods apart from the traditional ways so I can offer break in as part of the sale.

I've been reading about filament transformers set up to pass low voltage into speakers as opposed to passing signal through, and realized I could probably just use my variac to do the same thing.

Does anyone have experience with this? It sounds a bit risky, but I'm sure if set up correctly it would work well. I've got a brand new Celestion Heritage I wanted to break in. I thought I might give it a try, although I might wait for a less expensive speaker.

Thoughts?

[Structo]

Yeah, Jim at Scumback speakers has posted his routine before.

Here is a brief document for it.

Note: that he says Celestion speakers take a long time to break in.


Here is a calculator for break in.

http://www.unclespot.com/speakerbreakin.html

Then below is a word document with Jim's routine.

[Reeltarded]

My thought is that everyone is a wuss. Break in your own damned speakers, ya freaks!!



I have read about it over on Metro. Might search around a little there if no one here chimes in.

I break in speakers on amps, rawkin' it. heh.. Good Morning!

Oh great, Tom disrupted my smarm.

[Structo]

[JazzGuitarGimp]

Weber used to have a procedure outlined on their website, but they took it down some time ago. I guess too many people were frying perfectly good speakers. Their recommendation was to run the speaker at 1/3 its rated power. I will add the obvious and say that lower frequencies are better than higher, as you get more cone excursion - and the whole purpose of break-in is to soften up the cone and the adhesives that hold everything together. So 60Hz out of the wall is fine. I used 1/3 power at 81Hz (open low E string fundamental frequency) when I broke-in my Tone Tubby Alnco. After four days, the thing sounds freakin' amazing.

Here is the formula: P=E^2/R where:

P = Power, in watts
E = Applied RMS voltage
R = Speaker impedance

My TT is rated for 50W and has an impedance of 8 Ohms. I first solved for 1/3 the speaker's rated power: 50 / 3 = 17 watts, so:

17 = E^2/8, or:
17*8 = E^2, or:
136 = E^2, so,
the square root of 136 = 11.66V RMS

Connect your speaker to the output of the variac, making sure it is all the way down. It wouldn't hurt to measure it with your meter first, before connecting the speaker. Use a true RMS multimeter, set to AC Volts. And keep in mind that a variac is NOT an isolation transformer(!) Its output is referenced to neutral and ground, so be careful not to touch its output wires.

If you really want to get persnickety, refer to the manufacturer's data sheet for the speaker you're breaking in and look at the frequency vs impedance graph. All speakers have a resonant frequency and at this frequency, the speaker is extremely efficient. Therefore, its impedance rises dramatically at that frequency. For instance, the Jensen Vintage Reissue C12N has a resonant frequency of 112Hz, at which, its impedance rises to a little over 40 Ohms. At 60Hz, its impedance is 10 Ohms. So you _could_ use the equation to solve to 10 Ohms, which would give you a slightly higher break-in voltage (13.04V). But to be safe, I'd just use the rated nominal impedance.

[NickC]

My thought is that everyone is a wuss. Break in your own damned speakers, ya freaks!!



I have read about it over on Metro. Might search around a little there if no one here chimes in.

I break in speakers on amps, rawkin' it. heh.. Good Morning!

Oh great, Tom disrupted my smarm.

Actually, to take this concept a step further ..... it is essential to not only break in speakers by playing rawk music through the amp ...... but to play it in sleazy dive bars. Clinical double-blind studies will reveal in the future that amps-and-speakers broken in, in that fashion, have superior tone. It has to do with low-light ambience, exposure to neon lights, bar-ometric pressure, trace gases (largely alcohol, tobacco and stale perfume), and dubious electrical wiring (particularly the stage power being on the same circuit as refrigerators and elevator motors).

[Reeltarded]

See? Nick knows!

Maybe 30 years ago we replaced speakers that started sounding baggy, seriously. Everyone wants authentic but they don't want it authentically. I took the train to get this far. Woo woo! -covered in soot-

I have become that old bastard across the street from where I grew up. Awesome.

[Firestorm]

The idea of listening to 4 days of 60Hz or 81Hz tone at 17 watts isn't very appealing. You can theoretically bolt the speakers together face-to-face out of phase and get some cancellation, but almost as much "sound" comes off the backs, so it's imperfect. Some people have put the speakers in iso boxes for break-in, but I'd think you want some air flow to keep the voice coils a little cooler. If it were me, I'd mount the speakers in a cab and play my whole rock CD collection through them. More palatable than HUMMMMMM...

[Structo]

I believe Jim has built isolation boxes for breaking in speakers.

[JazzGuitarGimp]

The idea of listening to 4 days of 60Hz or 81Hz tone at 17 watts isn't very appealing. You can theoretically bolt the speakers together face-to-face out of phase and get some cancellation, but almost as much "sound" comes off the backs, so it's imperfect. Some people have put the speakers in iso boxes for break-in, but I'd think you want some air flow to keep the voice coils a little cooler. If it were me, I'd mount the speakers in a cab and play my whole rock CD collection through them. More palatable than HUMMMMMM...

At the time of my TT break-in, I live on five acres with several outbuildings. I mounted the Tubby into the Tweed Deluxe cab and moved it, a power amp, a signal generator, and a DMM out into another building. Never heard a thing. Unfortunately, I've moved and no longer have that luxury....

[Mark]

I know this isn't a scientific method. I used the 5vac tapping of a power transformer.

The noise from breaking in the speaker is significant so I put the whole lot into the garage and I used one of those power point timers so the speaker was only being broken in during business/working hours when most people would be away from home. I then ran the speaker this way for a week or so.

I can't say if the speaker was properly broken or sounded better, but it did sound good when used with the amp, so that can't be a bad thing.

[amplifiednation]

Well the noise is what I was trying to avoid, as I can easily leave a CD playing into the amp...so the speaker will produce 60hz him if connected to the variac? I have a closet in the basement...maybe I'll throw some dub reggae and let it sit while we are out tonight.

I'll check out that document, thanks Tom.

[selloutrr]

You would have a more realistic break in not putting a drum set through the speaker. Record a 5-10 guitar medley and put it on loop.

[amplifiednation]

You would have a more realistic break in not putting a drum set through the speaker. Record a 5-10 guitar medley and put it on loop.

That is a great idea

[Mark]

I think the question is what constitutes speaker break in?

How do you know there is any difference between playing it in and putting a 50 or 60 HZ signal across the speaker?

In theory a sweep generator would be best as it cover all frequencies.

I don't think breaking the speaker in with a 50/60 HZ is detrimental.

Bring on the double blind testing!