I'm wondering if my PA subs (EV SB180s- have the EVX180B 18" drivers in them) need to be broken in. I bought them many months ago but never really cranked it.
They're rated at 600 watts continuous, 2400 peak. I'm driving them in stereo mode with a Crown Macro-Tech 5000VZ amp, approx 1350 wpc cont. I bought these subs when Mars went outta business and they were pretty much never used. I drove them lightly (relatively speaking) in my house, but yesterday I decided to turn them up for maybe 30 seconds or a minute. I noticed for one there was a strong smell, like "new driver smell" if that makes any sense. Today I turned on the system again and I noticed that wow, it seems as though the bass got punchier. To make sure I made sure I played the same tracks with the same level patterns as indicated on both the amp and the mixer. I wonder if such PA subs actually need a break in time since they are rated to take 600 watts continuously for hours on in.
They're rated at 600 watts continuous, 2400 peak. I'm driving them in stereo mode with a Crown Macro-Tech 5000VZ amp, approx 1350 wpc cont. I bought these subs when Mars went outta business and they were pretty much never used. I drove them lightly (relatively speaking) in my house, but yesterday I decided to turn them up for maybe 30 seconds or a minute. I noticed for one there was a strong smell, like "new driver smell" if that makes any sense. Today I turned on the system again and I noticed that wow, it seems as though the bass got punchier. To make sure I made sure I played the same tracks with the same level patterns as indicated on both the amp and the mixer. I wonder if such PA subs actually need a break in time since they are rated to take 600 watts continuously for hours on in.
Actually music is probably not the best source for breaking in, as you need lots of power to get the suspension moving - breaking in is all about loosening up the new tight suspension, not heating up voice coils. Better would be low frequency sine wave, say around 10Hz - this could even be generated from PC sound card. A level of even 30W will produce large visible motion and loosen things up quickly - it is also a lot quieter !
Cheers
Cheers
I couldnt find my test CD with all the sinewaves, so I instead hooked up a pink noise generator and turned the crossover down low and turned up the volume. Also wired the subs out of phase but dang it was still pretty loud and everything was shaking. I should probably leave it like this for a while but listening to the pink noise rumble is really annoying. Maybe ill try to find that test CD. I think its workin though, I can smell the speakers still .
Break-in is a myth.
Speakers don't need high power break-in.
If you can smell them, you are probably making them too hot. Pink noise has a higher duty cycle than most music and it is quite a torture test.
If the speaker suspension loosens a bit in the first few hours of play, Fs goes down and Vas goes up, the two changes cancel out and frequency response changes very little, if at all. A 20% change in stiffness, which is quite a lot, makes a difference of perhaps 1dB in a sensitive box alignment.
Please note that many of the changes one sees in parameters after long use are reversible, and stiffness in particular is very temperature dependent.
I measured a woofer, it had an Fs of 35Hz, I played sine tones through it at Fs for a couple hours and Fs dropped to 31Hz. A couple hours later, Fs was back to 35Hz. I measured later on a cooler day (only ~10degrees cooler) and Fs was 43Hz.
Speakers don't need high power break-in.
If you can smell them, you are probably making them too hot. Pink noise has a higher duty cycle than most music and it is quite a torture test.
If the speaker suspension loosens a bit in the first few hours of play, Fs goes down and Vas goes up, the two changes cancel out and frequency response changes very little, if at all. A 20% change in stiffness, which is quite a lot, makes a difference of perhaps 1dB in a sensitive box alignment.
Please note that many of the changes one sees in parameters after long use are reversible, and stiffness in particular is very temperature dependent.
I measured a woofer, it had an Fs of 35Hz, I played sine tones through it at Fs for a couple hours and Fs dropped to 31Hz. A couple hours later, Fs was back to 35Hz. I measured later on a cooler day (only ~10degrees cooler) and Fs was 43Hz.
Ruler breaker.....What you are really doing is the equivalent of the diesel motor exhaust emissions test. You rev the motor up to max revs then (hopefully) the govener comes in, in the meantime the electronics is snifling it's rear end. There a condition for this, that the OH cam belt won't snap. Same with your speaker system.
There's an awesome power in this.........600W speaker system used on a 1.2kw amp and for testing on sine waves is inverse logic. One risks destroying the lot. Forget the peak power figures.
I don't trust Mosfet amps (whatever name) from the Orient. Ï've repaired too many and most (whatever the brand) have basically the same circuitry. To get 1.2Kw p.c the bridging technique is used with perhaps 4 mosfet output stages thrown in with some fancy current limiting. Beware, this most likely works after the speaker has gone for launch.
If I have got this one right, there used to be a golden rule in the industry that speaker music ratings (cont) should be rated 4 times max amplifer power. That seems to be ignored.
Using a CD with mixed tone is fine, but remember the continuous aspect. You don't hear all the sounds and it's those often do the damage.
Sine wave testing is risky for the speakers and usually exceeds IEC ratings. An 18" can tolerate alot of stick, but I don't like anything but good music even from new speakers. I would avoid digital for playing around with speakers at very high electrical levels without an LF interlock. Why one might ask. If LF warbling starts or instability at only a few Hz, then these mosfet amps will send this right through the system with the damaging effects of DC.
That is probably one of the reasons that speakers stand up very well with tube amps, as the o/p transformer will attenuate sharply at a low cutoff frequency. The small peerless 8" baskets off my 150W tube amp cope very well with the best steel band & reggae music (Tabu Combo) ,and that's a real test for the speakers and I haven't burnt them out yet..
Not all speakers need a run-in.... that is a misnomer. There will aways be some ageing but:-
Modern Hi Speakers with neoprene surrounds NO. The suspension and spiders is already highly compliant, made by modern processes.
Older speakers with paper surrounds with dusty paper cones will benefit from a good excursion, but don't overdo. A paper cone speaker with "honk" if overloaded. They are more fragile. Keep the cone dirty. The extra mass of crud reduces the resonance freq and smoothens the sound. Once the corrugated surround has limbered up, also expect a 15% reduction of resonant freq.
Musical instrument/PA speakers are entirely different. They have to be weather proofed, have designed stiff cones and hard sprung centering spiders to stand the rigours of bad handling and overloading. The cone surrounds and cones usually have a higher resonant frequency.
rich
There's an awesome power in this.........600W speaker system used on a 1.2kw amp and for testing on sine waves is inverse logic. One risks destroying the lot. Forget the peak power figures.
I don't trust Mosfet amps (whatever name) from the Orient. Ï've repaired too many and most (whatever the brand) have basically the same circuitry. To get 1.2Kw p.c the bridging technique is used with perhaps 4 mosfet output stages thrown in with some fancy current limiting. Beware, this most likely works after the speaker has gone for launch.
If I have got this one right, there used to be a golden rule in the industry that speaker music ratings (cont) should be rated 4 times max amplifer power. That seems to be ignored.
Using a CD with mixed tone is fine, but remember the continuous aspect. You don't hear all the sounds and it's those often do the damage.
Sine wave testing is risky for the speakers and usually exceeds IEC ratings. An 18" can tolerate alot of stick, but I don't like anything but good music even from new speakers. I would avoid digital for playing around with speakers at very high electrical levels without an LF interlock. Why one might ask. If LF warbling starts or instability at only a few Hz, then these mosfet amps will send this right through the system with the damaging effects of DC.
That is probably one of the reasons that speakers stand up very well with tube amps, as the o/p transformer will attenuate sharply at a low cutoff frequency. The small peerless 8" baskets off my 150W tube amp cope very well with the best steel band & reggae music (Tabu Combo) ,and that's a real test for the speakers and I haven't burnt them out yet..
Not all speakers need a run-in.... that is a misnomer. There will aways be some ageing but:-
Modern Hi Speakers with neoprene surrounds NO. The suspension and spiders is already highly compliant, made by modern processes.
Older speakers with paper surrounds with dusty paper cones will benefit from a good excursion, but don't overdo. A paper cone speaker with "honk" if overloaded. They are more fragile. Keep the cone dirty. The extra mass of crud reduces the resonance freq and smoothens the sound. Once the corrugated surround has limbered up, also expect a 15% reduction of resonant freq.
Musical instrument/PA speakers are entirely different. They have to be weather proofed, have designed stiff cones and hard sprung centering spiders to stand the rigours of bad handling and overloading. The cone surrounds and cones usually have a higher resonant frequency.
rich
That's funny, why do almost all quality speaker manufacturers post their drive specs after a 24 hour burn in? Heres a hint, it makes a difference. I've tested brand new drivers and again after a burn in and the specs change, not a lot, but enough to make a diffrence in box design. The spider is what breaks in the most on rubber surrounded drivers. On tweeters with ferofluid, the fluid spreads out more evenly after a few hours of use smoothing out the response. The variation in Fs RonE was talking about is more likely a change in barometric pressure and a sealed box that has not been allowed to equalize internal pressure(through a small hole or such). Believe what you wish but it does make a differnce!
Speakers change sound-caracter after a "brake in" period, how much depends on what speaker and how long brake-in depends on how much power it gets. 
- allmost everything changes, even the box! - cables, filtercomponents, drivers suspensions..
People who can`t hear this shouldn`t spend more money on hifi
- allmost everything changes, even the box! - cables, filtercomponents, drivers suspensions..
People who can`t hear this shouldn`t spend more money on hifi
Ken L,
Glad you have a sense of humor on the topic. It shows you have some understanding of hw controversial break-in is.
My favorite explanation for break-in is that a consumer calls a dealer and is dissatisfied. The dealer says, oh, don't worry, they just need to break in. The consumer gets used to the sound and break-in is assumed to be the reason for the "change". It is rather like the magician throwing the tissue over a child's head and the child "believing" they dissapear. It always takes a while to get used to any different speaker.
P.S. Show me some measurements of the lowthers pre and post break in, Frequency response, distortion, T/S or whatever. I don't deny a small change in stiffness in the first few minutes - probably most happens in QC at the mfg.
$700-2000/pr for an 8" fullrange, where can I buy em? You got the usual rear-horns, or ? I wonder if anyone near me has a pair, it would be interesting to hear them...
Glad you have a sense of humor on the topic. It shows you have some understanding of hw controversial break-in is.
My favorite explanation for break-in is that a consumer calls a dealer and is dissatisfied. The dealer says, oh, don't worry, they just need to break in. The consumer gets used to the sound and break-in is assumed to be the reason for the "change". It is rather like the magician throwing the tissue over a child's head and the child "believing" they dissapear. It always takes a while to get used to any different speaker.
P.S. Show me some measurements of the lowthers pre and post break in, Frequency response, distortion, T/S or whatever. I don't deny a small change in stiffness in the first few minutes - probably most happens in QC at the mfg.
$700-2000/pr for an 8" fullrange, where can I buy em?
You got the usual rear-horns, or ? I wonder if anyone near me has a pair, it would be interesting to hear them...
Life's too short to not have fun!Ron E said:
Nope. I've got _unusual_ Azurahorns. 38" LeCleac'h flare front horns with 8" Fostex FE206E's. (which required a pretty good breakin period) _big grin_
I'm about halfway between Atlanta, Ga and Charlotte NC, in Greenville, SC, about four blocks from I85. Come on by.
I don't listen to something because it measures well or poorly. I listen to music that sounds good or bad or beautiful.
How do you measure beautiful?
Where are you located?
Regards
Ken L
PS, I'm running a tube amp and all audio equipment through one powervar that's plugged into another powervar.
PPS if you will come by, I will make some A/B cable changes on interconnects and speakers for you. You can judge for yourself what differences there may be or not.
Hint: interconnects is where differences can most easily be heard in terms of cables.
I am NOT a beleiver in cables...... I think THAT is all in peoples heads.
But I do know that break-in makes a difference, with many drivers. I always thought the most noticable difference was in the upper midrange when breaking in a smaller driver. Before break-in many (notice I said "many", not all) drivers sound bright, but then eventually the upper and middle mid-range seems to come up to where it should be and meet the highs, so the highs don't change, but the speaker doesn't sound bright anymore.
What I wonder, is will these little Pioneer 1 1/2" or 2" (not sure what they are) mids I got from Parts Express benefit from a break-in, considering they have a plastic "spider". Not a conventional spider, more like three little plastic bands running where the spider would normally be and attaching to the bobbin. Pretty cool looking, but i don't know what a break in will do here. I just finished enclosures for them so we will see.
But I do know that break-in makes a difference, with many drivers. I always thought the most noticable difference was in the upper midrange when breaking in a smaller driver. Before break-in many (notice I said "many", not all) drivers sound bright, but then eventually the upper and middle mid-range seems to come up to where it should be and meet the highs, so the highs don't change, but the speaker doesn't sound bright anymore.
What I wonder, is will these little Pioneer 1 1/2" or 2" (not sure what they are) mids I got from Parts Express benefit from a break-in, considering they have a plastic "spider". Not a conventional spider, more like three little plastic bands running where the spider would normally be and attaching to the bobbin. Pretty cool looking, but i don't know what a break in will do here. I just finished enclosures for them so we will see.
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