2214 speaker pop

[pathfindermwd]

I had posted awhile back about my L100t's which I had recently purchased, popping at high bass levels. I had received some advice to recone them, which I was hesitant to do because of the cost. I finally did get the recone done with genuine JBL cones, and while I can tell the bass is much tighter and punchier, they will still pop at higher volume/bass levels/sources. I am a little disappointed, am even more baffled. Though I really like the sound and have little doubt about the quality of these speakers, this popping has me really scratching my head. None of my other speakers has ever done this. CF100's, CF150's, and cheaper ones still.

I had hoped that reconing them would be the solution, thinking that and old suspension might be the problem. A few of my friends own these speakers and they report that they will also pop if driven (too) hard. A friend suggests that other speakers will just distort, while these will instead pop. Seems reasonable.

I was hoping someone here might be able to add something more to this, and my general knowledge.

The enclosures are original L100T's, with T3 crossovers, powered by a NAD C375BEE/150w/channel

[Don C]

What signal source is in use when you hear the pop? A turntable?

[Robh3606]

Turn it down a couple of dB if it happens with all sources.

Rob:)

[pathfindermwd]

What signal source is in use when you hear the pop? A turntable?

No, any source. CD player, computer. This is an over-extension popping. Like when you hook up a 9v battery polarity check and a cone pops in and out to its limit.

[pathfindermwd]

Turn it down a couple of dB if it happens with all sources.

Rob:)

Hi, thanks Rob, I know, it's what I am forced to do, I just don't understand why the suspensions aren't holding them back from doing this.

[edgewound]

Check to see if the port tubes are still in place.

If they are, you can experiment with tuning the box to a leakage-damped port by stuffing some breathable open-cell foam in the port or some dacron fiber fill. This can prevent the cone from unloading below the tuning frequency of the enclosure...

Or...the spiders have torn loose from the voice coil former.

[pathfindermwd]

Check to see if the port tubes are still in place.

If they are, you can experiment with tuning the box to a leakage-damped port by stuffing some breathable open-cell foam in the port or some dacron fiber fill. This can prevent the cone from unloading below the tuning frequency of the enclosure...

Or...the spiders have torn loose from the voice coil former.


Thanks Edgewound. I checked the spider and it's fine both to the frame and the voicecoil. The original tubes are in place. I will have try the stuffing to see if it helps. Thanks for the the advise.

[Don Mascali]

Perhaps we are talking about the need for a high pass filter? :dont-know:

[DavidF]

I had posted awhile back about my L100t's which I had recently purchased, popping at high bass levels. I had received some advice to recone them, which I was hesitant to do because of the cost. I finally did get the recone done with genuine JBL cones, and while I can tell the bass is much tighter and punchier, they will still pop at higher volume/bass levels/sources. I am a little disappointed, am even more baffled. Though I really like the sound and have little doubt about the quality of these speakers, this popping has me really scratching my head. None of my other speakers has ever done this. CF100's, CF150's, and cheaper ones still.

I had hoped that reconing them would be the solution, thinking that and old suspension might be the problem. A few of my friends own these speakers and they report that they will also pop if driven (too) hard. A friend suggests that other speakers will just distort, while these will instead pop. Seems reasonable.

I was hoping someone here might be able to add something more to this, and my general knowledge.

The enclosures are original L100T's, with T3 crossovers, powered by a NAD C375BEE/150w/channel

Is the "pop" sporadic or more of a machine gun rattle?
What is the woofer doing when the pop occurs? Is there considerable visable motion with the cone? Does the woofer shift in or out and seem to hang in that position?
Has the crossover been altered from original spec, that you are aware of?
Can you swap out amps to check on the power side to confirm the problem is the speaker?
Me thinks the NAD is behaving badly under this load for some reason.

[pathfindermwd]

Is the "pop" sporadic or more of a machine gun rattle?
What is the woofer doing when the pop occurs? Is there considerable visable motion with the cone? Does the woofer shift in or out and seem to hang in that position?
Has the crossover been altered from original spec, that you are aware of?
Can you swap out amps to check on the power side to confirm the problem is the speaker?
Me thinks the NAD is behaving badly under this load for some reason.


Thank you for your reply David. Hmm, well It could be the amp, but a friends L100t does this as well on his own amp. When it pops I see the cone come out to a maximum level, so this leads me to believe that it is an elctronic sound, like when you use a 9v battery for a polarity check, and you get a pop or click. The crossovers came out of a L100s I also bought. The crossover wires to the speakers do not look original as the positive for the woofer is yellow and the negative blue. Whoever had the "S' had also switched the connectors on the tweeter itself. I caught theis one day and checked it against the "T" tweeters, the positive and negative spades on the tweeters were opposite! And you could see that the glue was messy suggesting that there had been some tampering. The "S" had always sounded terrible and we now think this is why. The "T" however sound great with the crossover, much less bright. Edgewound had hit upon something which I think has solved this problem, and I will reply to that in the following post.

[pathfindermwd]

Check to see if the port tubes are still in place.

If they are, you can experiment with tuning the box to a leakage-damped port by stuffing some breathable open-cell foam in the port or some dacron fiber fill. This can prevent the cone from unloading below the tuning frequency of the enclosure...

Or...the spiders have torn loose from the voice coil former.


Edgewound, I am glad you mentioned unloading. Is the ventpole screen/filter part of the restrictive system? Mine was completely deteriorated, just being foam. So I made one of my own from some aluminum screen and thin foam and glued them together to the back of the vent hole. I used the screen just to support the foam, and made sure the foam was very breathable. Hard to believe but I think the problem has been solved! I cranked them up and got no popping! It may have affected the outright output at higher levels, but if it stops the popping, I'm happy.

[robertbartsch]

...get the amp checked since it could be dumping DC into the outputs

[DavidF]

...get the amp checked since it could be dumping DC into the outputs
Agree. The description of the cone maxing at limits of suspension is a telling symptom. I am no electronics guru but this sounds like a problem strictly with the amp. Is this an 15 year or so old solid state? It seems a coindence that your friends system does the same thing. Is he using an older model as well?

If you have a digital mutlimeter you should check for DC at the speaker terminals. No input or speaker connection, amp on, set meter to DC mVolts, probes to each of the speaker terminals on one channel at a time. A reading of more than 50mV is a concern. More than 100 mV a problem.

[Chris Brown]

I've only had this happen a few times with my JBLs.

About 7 years ago I was using my L150's as mains in my home theater, watching Apollo 13 on Laserdisc (PCM audio track with NO dynamic range compression) during the Saturn 5 launch scene. Woofers popped a few times but you could tell the Pioneer SX-1050 I was using at the time was struggling via the faceplate lights dimming...

2nd time was when I had a loose connection on a cable I was using between my preamp and Yamaha P2201 amp, I touched it while the amp was on and it must have shorted for a second. The woofer did more than pop, what came out of my L100T's sounded like someone pushing a bookshelf (with books) down a staircase.

I have not had any issues during "normal" usage while supplying the speakers with good clean power, and I run the speakers pretty hard. My EQ settings are hardly flat (http://gotnorice.dnsdojo.com/eq.jpg), and I regularly measure as high as 133dBC with my meter.

[pathfindermwd]

ok so I finally dug out an old amp, some old JVC receiver. Same thing, it pops. On the JVC I noticed that in loud mode the woofer movement is wild, talk about good vibrations...or err not so good. Given the inability of the JVC to control woofer excursion and the inevitable woofer popping, I think this might have something to do with an under-powered amp.

The NAD on the other hand is maybe a year old. I have not done a DC volt test on it because I am not sure how it is done. How can I test only one channel at a time with the positive and negative on the volt meter (I am going to feel stupid)? But I am kinda leary at the notion of it being a problem with the amp, my CF150's are the "B" channel and they never pop with the same power on the same music, even at 98db sensitivity (and that's brutal output for them). And they used to be switched around, so it shouldn't be that. Why is the notion that popping can occur not being readily acknowledged? Under what conditions is what I feel I am chasing, so I can perhaps address it.

The addition of the foam filter to the vented pole piece has greatly helped, I mean I really have to get toward abuse for it to pop now. I lean towards it being under-powering, though I know this cant be the whole story. These 2214's are kind of an interesting breed because they have a very deep cone. Is this design contributing to this? Does it cause some kind of instability at high excursion?

The ramblings of a mad-man! :banghead:

[DavidF]

ok so I finally dug out an old amp, some old JVC receiver. Same thing, it pops. On the JVC I noticed that in loud mode the woofer movement is wild, talk about good vibrations...or err not so good. Given the inability of the JVC to control woofer excursion and the inevitable woofer popping, I think this might have something to do with an under-powered amp.

The NAD on the other hand is maybe a year old. I have not done a DC volt test on it because I am not sure how it is done. How can I test only one channel at a time with the positive and negative on the volt meter (I am going to feel stupid)? But I am kinda leary at the notion of it being a problem with the amp, my CF150's are the "B" channel and they never pop with the same power on the same music, even at 98db sensitivity (and that's brutal output for them). And they used to be switched around, so it shouldn't be that. Why is the notion that popping can occur not being readily acknowledged? Under what conditions is what I feel I am chasing, so I can perhaps address it.

The addition of the foam filter to the vented pole piece has greatly helped, I mean I really have to get toward abuse for it to pop now. I lean towards it being under-powering, though I know this cant be the whole story. These 2214's are kind of an interesting breed because they have a very deep cone. Is this design contributing to this? Does it cause some kind of instability at high excursion?

The ramblings of a mad-man! :banghead:

Yeah, it makes you wonder it isn't the speakers but I am still thinking amp issue. It seems less to do with the actual amp than what kind of demands are made on the amp. Can you remove any signal processors, swap out interconnects and speaker wire? Try your JVC on a clear FM channel, neutral Bass Treble, with some short ordinary speaker wires, same with the interconnect, and see what happens.

[pathfindermwd]

Yeah, it makes you wonder it isn't the speakers but I am still thinking amp issue. It seems less to do with the actual amp than what kind of demands are made on the amp. Can you remove any signal processors, swap out interconnects and speaker wire? Try your JVC on a clear FM channel, neutral Bass Treble, with some short ordinary speaker wires, same with the interconnect, and see what happens.


Yeah, it makes you wonder it isn't the speakers but I am still thinking amp issue. It seems less to do with the actual amp than what kind of demands are made on the amp. Can you remove any signal processors, swap out interconnects and speaker wire? Try your JVC on a clear FM channel, neutral Bass Treble, with some short ordinary speaker wires, same with the interconnect, and see what happens.

Hi Dave, I don't listen to the radio on the system. Sources are a computer, a DVD player, and a CD player. If I turned down the treble and the bass to neutral levels, I doubt I would get the speaker pop on any input (now that I added the foam to the pole piece), without either playing the source near full blast, or unless that source had very substantial bass to begin with. Of course if the solution were to turn down the bass, I'm afraid I would become pretty uninterested in the speakers all together :D.

I have had a total of 5 pairs of speakers hooked up to (and cranked to) this amp at home, and ran the 250's on it so my friend could see if he liked the NAD. It has never popped another set of speakers. It's not the amp....or should I say it's not an amp problem. On the other hand since I became aware of this popping we have successfully popped a total of 2 L100T's and 1 L100S's using two different amps/systems, it's not a source problem. Listening tests point to a woofer problem. But now that I have replaced the cones, it's not just an old woofer problem, though my experience says that deteriorated vented pole piece foam could make it worse. Maybe poor engineering of the vented pole piece is the problem. Other vented pole pieces I have seen use a heavy screen, not foam, and it's visibly clear that the restricted air space is substantial compared to an open hole, at least on the one's I've carefully looked at. One of the other posters talked about restricting box venting, and I was curious to find out if changing the venting of the pole piece would have the same net effect, it seems to have.
I believe that it's possible to pop any woofer (though I have NEVER popped any other woofer), this woofer seems particularly sensitive to it. Empirically, I can come to no other conclusion than to point to the speaker. It's a very good speaker, but they have a acute sensitivity to bass comparatively. Why is the persistent curiosity.

[DavidF]

" ...If I turned down the treble and the bass to neutral levels, I doubt I would get the speaker pop on any input ....if the solution were to turn down the bass, I'm afraid I would become pretty uninterested in the speakers all together :D..."

You are telling me that you are overdriving the amp, not the speaker.


" I have had a total of 5 pairs of speakers hooked up to (and cranked to) this amp at home, and ran the 250's on it so my friend could see if he liked the NAD. It has never popped another set of speakers. It's not the amp....or should I say it's not an amp problem. On the other hand since I became aware of this popping we have successfully popped a total of 2 L100T's and 1 L100S's using two different amps/systems, it's not a source problem..."

Amplifiers will react differently to speaker systems depending upon the loads.


" ...But now that I have replaced the cones, it's not just an old woofer problem...

I agree with ya there.


"...though my experience says that deteriorated vented pole piece foam could make it worse. Maybe poor engineering of the vented pole piece is the problem..

Completely disagree with you there.



" ...I believe that it's possible to pop any woofer (though I have NEVER popped any other woofer), this woofer seems particularly sensitive to it. Empirically, I can come to no other conclusion than to point to the speaker. It's a very good speaker, but they have a acute sensitivity to bass comparatively. Why is the persistent curiosity.

I honestly believe you are coming to the wrong conclusions. Everything you are telling me (you prefer high volume of sound, you use tone controls for significant emphasis of the signal, you don't think this popping would be a problem at more moderate sound more neutral sound levels) points to overdriving the amplifier when using this particular speaker system under your preferred listening style. You either need an amp capable of providing much more current or stick with speaker systems that don't stress out the amplifiers you currently use.

[pathfindermwd]

You are telling me that you are overdriving the amp, not the speaker.



Amplifiers will react differently to speaker systems depending upon the loads.



I agree with ya there.



Completely disagree with you there.




I honestly believe you are coming to the wrong conclusions. Everything you are telling me (you prefer high volume of sound, you use tone controls for significant emphasis of the signal, you don't think this popping would be a problem at more moderate sound more neutral sound levels) points to overdriving the amplifier when using this particular speaker system under your preferred listening style. You either need an amp capable of providing much more current or stick with speaker systems that don't stress out the amplifiers you currently use.


Yeah, I see what you are saying Dave. And, I think you make a very valid point. I did'nt intend to gloss over it, but I see that I did.
It makes sense since the NAD is rated at 150 watts, and the other amp that we used to pop others was rated the same. I did turn on the clip protection on the NAD the other day, it didn't seem to complain while the speakers softly poped, though I am not sure if that means anything.

I guess I didnt slow down enough to think through what you were saying, but I also said the same thing myself too when I said I could be under amping it. Until your last post nobody had made it clear that this speaker has specific power requirements or load considerations, which some corroboration about I was hoping for on a JBL forum. Though I got some input, none of it spoke to the real-world operation of the JBL speaker itself, which to me was the question. Overdriving the amp is a better description of what is happening than under-powering, and the right terminology somehow helps me understand it better. If it's true it's difficult for me to test, I would probably need a amp considerably beefier than mine (say 250 watts) to test against, and that's just not that easy to find or to invest in for these speakers, without knowing for sure. But maybe I'll get a head start on the 250's I'll buy someday. Sorry about being frustrated, but I am glad you made your point so much clearer for me. Thanks for having the patience (or frustration) enough to make it.

Best regards,
Mike

[gnolis]

Although this is a very old thread, it seems that I have the same POP sound issue. I also think that Mike did not solve his issue, at least as far as I have understood.
I have just managed AT LAST to buy a pair of used -but in excellent condition and fully serviced by the professional store I bought them- JBL XPL-200 (not the A version), with the 2214H-1 woofer. I did not ask what kind of service they did to the speakers (silly, I know), but they are in excellent looking condition and the foams seem new (probably they just re-foamed the woofers). I will contact them of course for the issue, but I live in Greece and they are located in UK, so this is not going to be easily solved....
I am driving the XPL's with two Denon Monoblock POA-6600A power amplifiers, but I get the same results of pop sound with the Onkyo TX-NR906 that I was using in the beginning for two weeks, before I put the Denon on and "downgraded" the Onkyo as a pre-amp. So, with the Onkyo alone, the amp seemed to reach its limits when the POP sound was happening, so I thought it was an amp lack of power issue. I also have other amplifiers in my collection to do tests, like the Carver AV-806x and the SONY TA-N55ES, but I do not think that there will be any change in the behavior.
The issue is happening in my left speaker only. The right speaker *maybe* has popped once, but I was afraid to raise the volume even more to repeat the pop, since the left speaker was popping hard at that time.
The popping is happening when the volume is at a level where "you can feed the bass moving your guts" and when the bass forces the cone to move towards the front side of the speaker (out direction), so the left speaker makes a very intense "POP", just as described from the previous forum member. It is as if you connect a battery to the woofer and you hear that "PAK" or "POP" (whatever you wanna call it) sound and you see the cone moving to the extend out.
The speakers are in a single-amp configuration. Unfortunately the cables I am currently using to drive them, are very cheap (1,5mm^2, flexible multiclone, that are used for electricity installations), I still haven't bought any Monster cable set (working on it, since the whole project is in progress with bi-amping etc). Plus the left current cable is 2 meters long, while the right cable is 1 meter long.
The same cables and the Onkyo amp were used for many months to my other JBL LX-66 speakers in my collection, that were driven very hard without any issue (of course, the LX-66 cannot handle the volume levels of the XPL-200 and I never connected the Denon power amps to them).
The speakers have overall an excellent sound and behavior, even at volumes that most of "normal" people cannot endure pleasantly, but when I "go crazy" and push them with high volume and the song has strong bass, then I get this stupid POP sound which is very frightening during these moments. You think that something broke or blown away!
I think that maybe the spider is loose and the speaker goes beyond the XMAX limit. The woofers are moving substantially when the volume is quite high, but -as far as I have noticed- the specific woofers do not seem to have a very wide range of movement, compared to my B&W ASW 675 SUB, which is "long throw".
I do not think I have reached a power bottleneck in my setup, since there is no distortion of any kind when I am pushing them, except of this POP sound. I believe I can personally endure the maximum power of these power amplifiers/speakers set, but this POP sound is "blocking" me, not to mention that it scares the shit out of me when it happens. I also feel that the bass that the XPL's are producing, is at least poor for my demands, I was expecting them to easily outperform the small 10-inch B&W sub, but that is not the case. I hope that when -and if- I solve this POP sound issue, they will be able to unleash the full potential of the woofers.
Sorry for the long post, I tried to be as detailed as possible. Any suggestions are welcome.

Best Regards,

George

[Chris Brown]

I think that maybe the spider is loose and the speaker goes beyond the XMAX limit. The woofers are moving substantially when the volume is quite high, but -as far as I have noticed- the specific woofers do not seem to have a very wide range of movement, compared to my B&W ASW 675 SUB, which is "long throw".
I do not think I have reached a power bottleneck in my setup, since there is no distortion of any kind when I am pushing them, except of this POP sound. I believe I can personally endure the maximum power of these power amplifiers/speakers set, but this POP sound is "blocking" me, not to mention that it scares the shit out of me when it happens. I also feel that the bass that the XPL's are producing, is at least poor for my demands, I was expecting them to easily outperform the small 10-inch B&W sub, but that is not the case. I hope that when -and if- I solve this POP sound issue, they will be able to unleash the full potential of the woofers.
Sorry for the long post, I tried to be as detailed as possible. Any suggestions are welcome.

Best Regards,

George

http://www.jblproservice.com/pdf/Thiele%20Small%20Parameters/Theile%20Parameters.pdf

Here you can see that the XMax of the 2214H is only 6.6 millimeters. Not a huge figure really, especially compared to a typical subwoofer. Nothing is working incorrectly, you are simply bottoming out the woofer. The voice coil reaches the bottom of the voice coil gap and makes contact with the pole piece (part of the magnet). This is what causes the POP sound.

The 2214H woofer can handle quite a bit of power, and put out a lot of bass, but not at frequencies significantly below the tuning frequency of the cabinet. Below that point, output drops off very quickly and the woofer is able to move too freely, which is why it's exceeding XMax (actually exceeding "XMech" once it makes contact with the pole piece). The L100T and XPL200 are ported designs, where the resistance of the air movement through the port damps the movement of the cone, but not so much when below the tuning frequency.

It's just a matter of what it was designed to do. Specs of both the XPL200 and L100T show response down to 35Hz at -6dB. 35Hz is not an amazingly low figure (compared to something like a quality subwoofer) and output is already down a bit (-6dB) by that point anyway. Those aren't bad numbers for a speaker really. *Most* music does not even contain bass at 35Hz or below, but obviously some does.

The real solution here, if you are playing music with extremely low-frequency bass and doing so at at loud levels, is to integrate a quality subwoofer into your system. Do this using either an external crossover of some sort or use the crossover that is built-in to the subwoofer (usually by running your speakers through the high-level input/outputs on the subwoofer) to re-direct the problem frequencies away from your speakers to the subwoofer instead.

Understand that integrating a subwoofer into your system does NOT equate to giving up on the goal of significant bass output from your XPL200 speakers. It doesn't have to be like someone who runs small bookshelf speakers with a subwoofer and a crossover set to 80-120hz. With speakers like the XPL200 you can get away with a much lower subwoofer crossover frequency. Perhaps something around 40Hz give or take. There is still a LOT of bass above 40Hz, and once you've eliminated the possibility of problematic ultra-low frequency content bottoming out the woofers, you can then get away with really pushing the XPL200s hard with bass content that they can handle. Anything lower will be handled by your subwoofer exclusively, but that should be limited to only very low frequencies at that point.

I have L100Ts. I power them with 700wpc and I push them VERY hard, but I also run two subwoofers. That gives me the freedom to push the 2214H woofers in my L100Ts to the limits of what they can do rather than forcing them to do something they can't.

[DerekTheGreat]

Hi George,

I have a set of L150A's and am dealing with the same thing; a popping noise when driving the speakers, and where only one woofer does it and the cone is coming "out" into the room, not inside the enclosure. Initially, both of my 128H's did this. I had them reconed and then only one did it, now that woofer is dead. I think it is the result of a bad recone job as before it died I could move the woofer by hand and would feel the voice coil rubbing on something. It could also be the result of driving the speakers too hard, dedicated subwoofers are what I'm going to look into as well, should the next recone produce similar results. That or I'll just use an equalizer to attenuate the low frequencies. If you've got the time, check out my thread, "Help with 128H's in L150A's"

[330indy]

great response here. I have similar experience with mine, reconed them and now put the bottom octave burden on a Klipsch sub. all is well with any type of music now.... only reason I use an EQ with the L100Ts is too tame some of the mids with old recordings....

http://www.jblproservice.com/pdf/Thiele%20Small%20Parameters/Theile%20Parameters.pdf

Here you can see that the XMax of the 2214H is only 6.6 millimeters. Not a huge figure really, especially compared to a typical subwoofer. Nothing is working incorrectly, you are simply bottoming out the woofer. The voice coil reaches the bottom of the voice coil gap and makes contact with the pole piece (part of the magnet). This is what causes the POP sound.

The 2214H woofer can handle quite a bit of power, and put out a lot of bass, but not at frequencies significantly below the tuning frequency of the cabinet. Below that point, output drops off very quickly and the woofer is able to move too freely, which is why it's exceeding XMax (actually exceeding "XMech" once it makes contact with the pole piece). The L100T and XPL200 are ported designs, where the resistance of the air movement through the port damps the movement of the cone, but not so much when below the tuning frequency.

It's just a matter of what it was designed to do. Specs of both the XPL200 and L100T show response down to 35Hz at -6dB. 35Hz is not an amazingly low figure (compared to something like a quality subwoofer) and output is already down a bit (-6dB) by that point anyway. Those aren't bad numbers for a speaker really. *Most* music does not even contain bass at 35Hz or below, but obviously some does.

The real solution here, if you are playing music with extremely low-frequency bass and doing so at at loud levels, is to integrate a quality subwoofer into your system. Do this using either an external crossover of some sort or use the crossover that is built-in to the subwoofer (usually by running your speakers through the high-level input/outputs on the subwoofer) to re-direct the problem frequencies away from your speakers to the subwoofer instead.

Understand that integrating a subwoofer into your system does NOT equate to giving up on the goal of significant bass output from your XPL200 speakers. It doesn't have to be like someone who runs small bookshelf speakers with a subwoofer and a crossover set to 80-120hz. With speakers like the XPL200 you can get away with a much lower subwoofer crossover frequency. Perhaps something around 40Hz give or take. There is still a LOT of bass above 40Hz, and once you've eliminated the possibility of problematic ultra-low frequency content bottoming out the woofers, you can then get away with really pushing the XPL200s hard with bass content that they can handle. Anything lower will be handled by your subwoofer exclusively, but that should be limited to only very low frequencies at that point.

I have L100Ts. I power them with 700wpc and I push them VERY hard, but I also run two subwoofers. That gives me the freedom to push the 2214H woofers in my L100Ts to the limits of what they can do rather than forcing them to do something they can't.