Speaker Break In and How to Do It Yourself

Discussion of Speakers, Cabinets and Cabinet Building

Moderators: pompeiisneaks, Colossal

User avatar
Scumback Speakers
Posts: 754
Joined: Tue Nov 14, 2006 5:49 pm

Speaker Break In and How to Do It Yourself

Post by Scumback Speakers »

Speaker Break In and How to Do It Yourself, with a mythbusters section

There’s been a lot of speculation on speaker break in for guitar amp speakers on the Internet. Much of the information online is based on subjective opinion, and not much real world testing.

I’m writing this article to try to dispel the myths and misconceptions.

First, yes speakers break in. That’s a fact. How long they take to break in has many factors including the materials used in the speaker, how flexible those materials are (or can be) and how long it takes to loosen them up.
All speakers are made in pretty much the same manner using a cone, attached to a voice coil, a dust cap to protect contaminants (dust, dirt, etc) from getting into the voice coil and it’s gap around the pole piece it is centered around and a spider/suspension piece that holds the voice coil in place to keep it centered at the bottom, and the cone is glued to the frame to keep it stable on the frame edge.

Some speakers use a compound called “doping” around the top cone edge and the dust cap, some don’t. It depends on what the speaker maker is designing the tone of the speaker for, and other factors affecting the control of the cone from moving too wildly and producing cone cry, and other typically unwanted noises.
While a speaker works fine out of the box, typically they’re very tight, bright and don’t respond as well to the nuances of pick attack, gain, volume level adjustment we guitar players like to employ while playing. Breaking in the speaker makes the cone, spider and related parts more pliable, and easier to move. When this occurs you can get a fatter bass response, trim the treble harshness, widen the midrange tones and warm up your entire tone, which results in a bigger, broader speaker voice.

As guitar players, anything that broadens our tone, while not ripping our heads off with treble is usually considered a good thing!

Second, getting a speaker broken in takes a lot of loud playing time (more than 25w typically), or a lot of movement to the speaker parts to make them more pliable, which makes the speaker more responsive. How much time and volume depends on your speaker’s construction materials, and how big your magnet is (light 35 oz to heavy 50 oz and beyond to 14 lb magnets in JBL’s and EVM 12’s). The reason the magnet size is a factor is that the stronger the magnetic pull on the cone, the harder the cone is to move. That’s because the heavier magnetic strength limits the cone movement more than a lighter magnet since the voice coil is reacting with the magnet. That’s why an “H” heavy magnet speaker takes longer to break in than an “M” medium magnet weight. Of course you can lengthen the break in time on the H model to get broken in, and typically it’s an extra 35-40% longer due to that difference.

Third, breaking in the speaker naturally by playing. Go ahead, it’s going to break in eventually, but the louder you play and the more often you play, the faster it breaks in because a bigger signal is sent with the volume increase that moves the speaker parts more, making them more pliable and responsive.
Breaking in the speaker can be done in other ways as well. You can wire your speakers to your stereo system at home, turn on some music with lots of low end, low mids, turn up the bass and mids, turn down the treble, turn up the volume to approximate 25w or more of power and let them get played by the stereo to break them in. Make sure you have neighbors that aren’t too close, won’t call the cops on you if they are, and like the music you’ve chosen to blast through your speakers while you’re at work!

You can also use a variac (variable output transformer) to break them in. The variac puts out a 60 cycle hum that moves the speaker parts similar to a bass guitar in the low E and A strings. The bass frequencies move the speaker more than the treble frequencies, so they’re preferable to break in from my tests. The major consideration in this method is how much voltage to use so you don’t fry your voice coil while still moving the speaker. The smell of a burnt voice coil is not pleasant so let’s avoid that, not to mention the expense involved with reconing the speaker, since you then have to break it in again.

Variac break in procedure.

First you need a variac with at least a 1 amp capacity, with a dial that lowers the voltage to 5 volts. These are pretty common to find, and run around $80 or so on eBay with shipping.
Next you need a cable to hook up to your speakers. I use a 4x12 cabinet that has a ¼ jack on it (like your guitar amp speaker output jack) but I use an old computer cable with the IEC end (not the male 3 wire prong end, you need that to plug into the variac). You cut off the IEC end of the cable that plugs into your computer (the female end), and you’ll usually find three colored wires, white, black and green. The white goes to the positive of the ¼” plug, the black to the negative of the plug, and the green wire is cut and taped off. You need this type of cable to handle the voltage the variac will send to your speakers.

DO NOT USE AN INSTRUMENT CABLE, YOU WILL FRY IT IN SHORT ORDER!

Next you’ll hook up your cab to the variac, but there is a very important task you need to do FIRST.
You will need a multimeter. You’ll need this to check the voltage coming out of your variac through the cable you’ve made. This is critical. Too much voltage, fried speaker. I’ve done extensive testing on breaking in speakers, and the higher wattage voice coils take longer to break in and can handle more volts, the lower wattage coils less time, less volts. You will set the variac dial to the lowest setting on its dial. Plug in your cable (loose), not in the speaker jack yet. Hold the multimeter leads on the plug end, red cable to the tip of the plug, black cable to the barrel of the plug. Turn on the variac and slowly turn the dial until it reads 9 volts (or close). This is the setting I use for most speakers that are low power models (20-30w). If you have a 65w speaker, then you are safe at 11-12 volts.

How I arrived at these voltage settings is simple. I measured my 50w Marshall clone with the volume set at 9. According to previous measured results with an oscilloscope, waveform generator, etc my amp builder determined it puts out 95w at 9 on the volume knob resulting in a voltage reading of 36 volts to the cable in the speaker jack.
If you set the variac at 9 volts, you’re essentially sending about 25w to the speaker, which is many speakers limit. Assuming your speakers are wired in parallel each one gets that voltage. It will be quite loud at this setting, you’ll want to leave the room, or do this in your garage, studio or your worst enemies garage, if you can gain access!
With the 65w speaker types you can go to 11-12v, which is around 35w of power sent.

I strongly advise you not to exceed this voltage so you don’t fry your speaker voice coil. You could do a higher voltage at your own risk, but then you’d need a digital timer set to two hours on, one hour off to cool the voice coil, and have it run for about two days. For a decent amount of break in you’ll need to do an M magnet about 16 hours, and around 20-24 hours for an H magnet.

This gets the speaker broken in and sounding warmer quite nicely. There is still about 5-10% of break in left to do, and that can only be done by more playing, or loud club/concert level playing as it will move the cone even more due to playing attack, palm muting, open chords, etc. While the variac could do this, it would be bordering on being unsafe for the voice coil to run that hot with a higher voltage used without taking breaks. I recommend no longer than 24 hours in one session at the 9-12v settings described above, then give the speakers time to cool (feel the magnet, if it’s hot, time to let it cool) before doing anymore.

You can also run the variac at a lower voltage level, and run it longer. I don’t recommend more than 3 days with my speakers (with break time to cool), and this is in a closely controlled/monitored environment. It requires removing the speaker from the cab each day, test it with a waveform generator to make sure the voice coil isn’t burnt and rubbing every 24 hours. Most clients aren’t going to go for that much hassle, so it’s your choice. I rarely do it myself, as I find it’s more fun to go to an open mic night or jam session with friends and do it that way.

There are plenty of myths out on the net, time to dispel some.
1) You cannot break in a speaker properly with 5 minutes of playing, I don’t care what volume you use. Whoever came up with that isn’t a guitar player.

2) You cannot run your speakers at 26 volts all night and expect them to survive. I have documented pictures of the results, and it’s not pretty. Most often you will fry the voice coil, in one case the speaker caught on fire and burned the cone/coil and the wire attached to it. I was lucky. My FBI break in cab (FBI = Factory Break In) has a lid on it, which limits the airflow to feed a fire. However I was very upset to find this speaker burnt up following the builder’s break in technique, and then they refused to rebuild it although it was brand new and I used their instructions (which they have now removed from their site so as not to tarnish the legacy of the person who posted those instructions) to break in the speaker.

3) You can break in a speaker too fast, and too far. I’ve done that as well in my testing, which is why the voltages I’ve set out above are what I have found are safe. While the speaker may be broken in, it can be so loose that it sounds tired. All speakers break eventually, they don’t last forever. But artificially breaking them in to sound good is one thing. Doing it to the point of destruction and poor tone won’t make you happy.

4) Power handling/volume. A 20w M75-PVC Scumback with the KRAFT paper voice coil is just as loud as the 65w nomex version. The voice coil determines the power handling, not the decibel output. That is a function of the cone used, magnet weight, etc. A higher powered M75 is just as loud as a lower powered M75. It’s the same for my entire line, so low power speakers break in faster, but are the same volume as the high powered speakers.

5) Large magnets put out more decibels. H series speakers usually are in the 99/100 db range, M series around 96/97 db, it depends on the cone type (55 or 75hz, and what rib type is used on the cone, there are differences). Your typical JBL or EV speaker has a 14 lb magnet, which is why it puts out 104 db. They also use 4” wide voice coils to wrap more wire on the coil to handle more power. The myth comes from that build scenario. It’s not the higher power 150/200w voice coil that makes the speaker louder, it’s the huge magnet field from the larger magnet.

6) Cone Cry: You can make any speaker produce cone cry. The object is to make sure it doesn’t happen in the guitar’s usable range, which is usually from round 80 Hz to 5khz. Cone cry is a nasty noise, showing up sometimes as a howl like a werewolf, or a bright pinging tone on high B & E strings, to a double tone that’s not a full octave off the original note it’s crying from. None of it sounds good. The only way around it is to dope the cone more, or not play those notes, or use it with your fuzz pedal to drown it out.

7) Square wave signals…these are generated when you use too much fuzz, overdrive, and the tone is so saturated it sends a square wave to the speaker. Speakers don’t tolerate square waves for a long time, they eventually get overheated and hang up in a set position in their excursion and result in getting a voice coil burn or fry. If you’re going to use fuzz, get 3 times the rated power of your amp’s power to offset the heat induced by the square wave. Even then there are no guarantees.

8) “Pushing the speaker hard sounds best!” Another myth that’s been going on forever. You will eventually ruin the speaker by “pushing it” with overdrive pedals without enough speaker power handling. You cannot run your 100w Marshall on 10 into a single 4x12 cab with four 25w or 30w speakers. Why? Because your amp is rated conservatively. That means once you pass it’s clean tone (3% distortion total) into a singing overdrive tone (naturally with the amp turned up around 6-8) you’ve gone from 100w clean at 4 on the volume knob to 180-200w at 8 on the volume knob. They sold two 4x12 cabs with those old Marshalls for a reason, they knew the speakers would blow. I have a JCM 800 manual available online that shows the 100w JCM 800 put out 115w clean at 3% distortion (4 on the volume knob) and in excess of 170w at 10% distortion (around 8 on the volume knob). Email me if you want it or go to this link to see it yourself.

http://www.scumbackspeakers.com/specs/j ... rspecs.jpg

9) In closing, you can’t just run amok on your amp with your speakers unless you have enough power handling to run amok. Make sense? Towards that end I always recommend you get twice the speaker power handling of your amp’s clean rated power. That means 100w of speaker power handling for a 50w amp if cranked, and 200w for a 100w amp if cranked (or as I like to call it DIMED!). No one wants to fry their speakers or their output transformer after you fry your speakers. It’s expensive, you’re not playing through an amp and most electric guitars aren’t designed to sound good as an acoustic.
I hope this article helps clear up some of the myths, untruths, and regurgitated hype that’s on the internet regarding speakers and speaker break in. If not, email me and I’ll try to help. sales@scumbackspeakers.com

Now, get back to playing!

Jim Seavall
President, Scumback Speakers & Cabs, Inc.
Scumback - Guitar Speakers That Kick Ass!
http://youtu.be/u6U30BV2kFM
sales@scumbackspeakers.com
www.scumbackspeakers.com
https://www.facebook.com/scumbackspeakers/
https://www.instagram.com/scumback_speakers/
User avatar
David Root
Posts: 3540
Joined: Fri Aug 04, 2006 3:00 pm
Location: Chilliwack BC

Re: Speaker Break In and How to Do It Yourself

Post by David Root »

Thank you very much Jim for sharing your experience so generously. Much of what you say was news to me and I'm sure it will all be very helpful for all of us.
When I was a boy I was told that anyone could become President. I`m beginning to believe it--Clarence Darrow
User avatar
xtian
Posts: 6990
Joined: Mon Apr 19, 2010 8:15 pm
Location: NorCal
Contact:

Re: Speaker Break In and How to Do It Yourself

Post by xtian »

Really great, Jim! I think you should put the summary of benefits ("a bigger, broader speaker voice") paragraph in bold.
I build and repair tube amps. http://amps.monkeymatic.com
User avatar
Ken Moon
Posts: 610
Joined: Tue May 08, 2007 2:41 pm
Location: Denver

Re: Speaker Break In and How to Do It Yourself

Post by Ken Moon »

Great stuff - thanks :D

At what frequency (approx) does the breaking-in effect the high end?

And how does that compare to the roll-off frequency of the various Treble/Tone controls (guitar Tone, amp Treble, amp Presence)?

In other words, would trimming the treble and boosting the bass on the guitar/amp until the speaker is broken in by regular use, accomplish the same thing as breaking in the speakers?
User avatar
Scumback Speakers
Posts: 754
Joined: Tue Nov 14, 2006 5:49 pm

Re: Speaker Break In and How to Do It Yourself

Post by Scumback Speakers »

xtian wrote:Really great, Jim! I think you should put the summary of benefits ("a bigger, broader speaker voice") paragraph in bold.
I actually had other lines bolded, but when you copy and paste between forums they don't seem to all recognize the same html tags & codes.
Ken Moon wrote:Great stuff - thanks :D

In other words, would trimming the treble and boosting the bass on the guitar/amp until the speaker is broken in by regular use, accomplish the same thing as breaking in the speakers?
Sure, it would just take a whole lot longer and your guitar would sound muted/muffled until it did. But if you don't mind doing that for 50-60 hours of normal playing, be my guest!

Seriously, I would probably go nuts if I had to break in a speaker sounding like a bass guitar tone. It's great for the break in of the cones, not so much for the tone of your guitar while you're breaking it in.
Scumback - Guitar Speakers That Kick Ass!
http://youtu.be/u6U30BV2kFM
sales@scumbackspeakers.com
www.scumbackspeakers.com
https://www.facebook.com/scumbackspeakers/
https://www.instagram.com/scumback_speakers/
User avatar
Ken Moon
Posts: 610
Joined: Tue May 08, 2007 2:41 pm
Location: Denver

Re: Speaker Break In and How to Do It Yourself

Post by Ken Moon »

OK, Jim. You talked me into breaking in my new Swamp Thang with 50-60 hours of loud playing :D

If my wife has any questions on why I just HAVE to do this, I'll refer her to you 8)
User avatar
Scumback Speakers
Posts: 754
Joined: Tue Nov 14, 2006 5:49 pm

Re: Speaker Break In and How to Do It Yourself

Post by Scumback Speakers »

Ken Moon wrote:OK, Jim. You talked me into breaking in my new Swamp Thang with 50-60 hours of loud playing :D

If my wife has any questions on why I just HAVE to do this, I'll refer her to you 8)
Right...good luck with only 50-60 hours of loud playing with that one, and your wife understanding it's all my fault. We all know you're going to go 150-160 hours and say I made a typo...then have her call me all pissed off!

LOL
Scumback - Guitar Speakers That Kick Ass!
http://youtu.be/u6U30BV2kFM
sales@scumbackspeakers.com
www.scumbackspeakers.com
https://www.facebook.com/scumbackspeakers/
https://www.instagram.com/scumback_speakers/
User avatar
martin manning
Posts: 13079
Joined: Sun Jul 06, 2008 12:43 am
Location: 39°06' N 84°30' W

Re: Speaker Break In and How to Do It Yourself

Post by martin manning »

Good stuff, thanks!
tubeswell
Posts: 2337
Joined: Thu Mar 27, 2008 6:42 am
Location: Wellington. NZ

Re: Speaker Break In and How to Do It Yourself

Post by tubeswell »

Great pointers! FWIW I've found that a bit of whumping from bias vary tremolo set to max depth and speed with vol dimed, but no amp input signal going in) also helps soften up new cone rims a bit - albeit somewhat quietly.
He who dies with the most tubes... wins
bluesfendermanblues
Posts: 1314
Joined: Tue May 22, 2007 12:57 pm
Location: Dumble City, Europe

Re: Speaker Break In and How to Do It Yourself

Post by bluesfendermanblues »

Thanks for sharing your knowledge and experience gained from years of experimentation.

I was wondering if speaker units impedance has an impact on your choice of duration of voltage treatment. ...

E.g. if an 8 ohm, 25w speaker with medium size magnet gets 16 hours a 9 volts, would a 4 ohm speaker unit get more or less hours?
Diva or not? - Respect for Mr. D's work....)
User avatar
Scumback Speakers
Posts: 754
Joined: Tue Nov 14, 2006 5:49 pm

Re: Speaker Break In and How to Do It Yourself

Post by Scumback Speakers »

bluesfendermanblues wrote:Thanks for sharing your knowledge and experience gained from years of experimentation.

I was wondering if speaker units impedance has an impact on your choice of duration of voltage treatment. ...

E.g. if an 8 ohm, 25w speaker with medium size magnet gets 16 hours a 9 volts, would a 4 ohm speaker unit get more or less hours?
In my tests I only had 8 and 16 ohm speakers, which is what I make. 4 ohm speakers in the British style speakers never sounded right, something to do with the wire size, etc. My voice coil maker doesn't make them since they sound like a$$ to them as well.

Here's the deal on the voltage...an 8 ohm speaker vibrates more than a 16 ohm speaker with the same voltage applied to it, thereby getting more power. So the lower the ohm rating, the more power it receives in comparison to a 16 ohm speaker. Ohms laws can go into all the details if you want to look it up online.

It takes approximately 3 more volts to a 16 ohm speaker to equal the vibration/cone movement of an 8 ohm speaker in my tests.

So you'll need about 3 volts less for a 4 ohm speaker.

Keep in mind the power handling of the voice coil also is a factor, so you can't use the 8 ohm 65w setting and apply just 3 volts less to a 4 ohm 25w speaker and expect it to be ok.

If you have a 4 ohm 25w speaker, I wouldn't give it more than 5-6v max. As for the duration, it still depends how stiff the cone & spider is, how much doping is on the cone, how big the magnet is to dissipate the heat, etc.

Hope that answers your question.
Scumback - Guitar Speakers That Kick Ass!
http://youtu.be/u6U30BV2kFM
sales@scumbackspeakers.com
www.scumbackspeakers.com
https://www.facebook.com/scumbackspeakers/
https://www.instagram.com/scumback_speakers/
Jered
Posts: 117
Joined: Wed Sep 10, 2008 8:26 am
Location: Orange County CA

Re: Speaker Break In and How to Do It Yourself

Post by Jered »

Any thoughts on the earcandy speaker break in CD? I have only used it twice, once on a weber 12" alnico 8 ohm 30 watt and once on a WGS green beret 16 ohm 25 watt. Really helped open up both speakers. The weber was so harsh and brittle I hated it, after the cd break in it is my fave speaker, honestly.
I have no affiliation with this company or any of its products, just wondering others thoughts on the product. It was only 5 hours each speaker and easy to do. Details are on the earcandy.com website. Thoughts? Thanks
bluesfendermanblues
Posts: 1314
Joined: Tue May 22, 2007 12:57 pm
Location: Dumble City, Europe

Re: Speaker Break In and How to Do It Yourself

Post by bluesfendermanblues »

Southbay Ampworks wrote:
bluesfendermanblues wrote:Thanks for sharing your knowledge and experience gained from years of experimentation.

I was wondering if speaker units impedance has an impact on your choice of duration of voltage treatment. ...

E.g. if an 8 ohm, 25w speaker with medium size magnet gets 16 hours a 9 volts, would a 4 ohm speaker unit get more or less hours?
In my tests I only had 8 and 16 ohm speakers, which is what I make. 4 ohm speakers in the British style speakers never sounded right, something to do with the wire size, etc. My voice coil maker doesn't make them since they sound like a$$ to them as well.

Here's the deal on the voltage...an 8 ohm speaker vibrates more than a 16 ohm speaker with the same voltage applied to it, thereby getting more power. So the lower the ohm rating, the more power it receives in comparison to a 16 ohm speaker. Ohms laws can go into all the details if you want to look it up online.

It takes approximately 3 more volts to a 16 ohm speaker to equal the vibration/cone movement of an 8 ohm speaker in my tests.

So you'll need about 3 volts less for a 4 ohm speaker.

Keep in mind the power handling of the voice coil also is a factor, so you can't use the 8 ohm 65w setting and apply just 3 volts less to a 4 ohm 25w speaker and expect it to be ok.

If you have a 4 ohm 25w speaker, I wouldn't give it more than 5-6v max. As for the duration, it still depends how stiff the cone & spider is, how much doping is on the cone, how big the magnet is to dissipate the heat, etc.

Hope that answers your question.
Yes, Thank you very much.

I have summed up your info in the table below for a quick reference guide. If this is too simplified. please let me know and I'll remove it.
Attachments
Skærmbillede 2016-02-18 14.56.01.png
Diva or not? - Respect for Mr. D's work....)
User avatar
Scumback Speakers
Posts: 754
Joined: Tue Nov 14, 2006 5:49 pm

Re: Speaker Break In and How to Do It Yourself

Post by Scumback Speakers »

Slight changes based on extensive long testing last weekend.

Testing shows the 8 ohm speakers can run at 12v for 65w, 9v for 20/25w/30w

Testing shows the 16 ohm speakers can run at 15v for 65w, 12v for 20-30w

I did FBI service to two M75-PVC 8 ohm 20w KRAFT paper voice coil speaker for three days. That's 16 hours per day, at 9v, with appropriate cooling off periods during the three days.

The cone/surround/spider got really loose after three days. When compared to my pre rola 25w Greenback G12M's, the G12M's were a little bit looser, but not much. I figured that each day of FBI put about 10 years of wear on the speaker, based on how loose the cone/spider moved.

When my client got the two speakers he put them in a 2x12 cab and played them back to back with his 68 G12M loaded Marshall basketweave cab (16 ohm). His comment to me on the voice mail was "You totally nailed it. I couldn't be happier with this sound in a 2x12 vs a 4x12."

He's got six more speakers on order now due to that, no time to break them in himself.

Just be aware that you can over break in a speaker without cooling it off properly and ruin it. In fact the first M55-PVC 16 ohm 20w I did the same thing to last weekend had a bad cone and cracked 1/3rd of the way around the gasket. Yep, new cone, but turned out to be a bad new cone and split.

The replacement speaker has been in the FBI box for two days now and is still ok. Crossing my fingers that it's ok today so I can ship it out to the client.

And as always, use these guidelines at your own risk. I did these for safe voltages for the Scumback line of speakers, your mileage may vary.
Scumback - Guitar Speakers That Kick Ass!
http://youtu.be/u6U30BV2kFM
sales@scumbackspeakers.com
www.scumbackspeakers.com
https://www.facebook.com/scumbackspeakers/
https://www.instagram.com/scumback_speakers/
bluesfendermanblues
Posts: 1314
Joined: Tue May 22, 2007 12:57 pm
Location: Dumble City, Europe

Re: Speaker Break In and How to Do It Yourself

Post by bluesfendermanblues »

@Jim

I think the voltage/wattage conversion of respectively 9 and 12 volts are a bit too high.

I assume that you measured your Marshall clone to put out 36 volts a vol setting "9" into a fixed 8 ohm (dummy) resistor. However, a real "8" ohm speaker usually has a lower ohm reading.

If you put 9 V ac into a Greenback (http://celestion.com/product/24/heritage_series_g12m/) clone which measures 6.57Ω across its poles, applying ohm law, you get:

U=R x I => 9 = 6.57Ω x I => 9 / 6.57Ω = I => I =1.37

If this calculation is correct 9 volts ac translated to
Watt (VA)= I x U => 1.37 x 9 = 12.3 watts


and 12 volts into a 12G65 ( http://celestion.com/product/26/heritage_series_g1265/) converts to

U=R x I => 9 = 6.9Ω x I => 9 / 6.9Ω = I => I =1.3

1.3 x 12 = 15.7 watts


Am I correct. If so those wattage numbers makes more sence to me in regards to the 20watt speaker, M75.
Diva or not? - Respect for Mr. D's work....)
Post Reply