4412 power handling.

[Chris Brown]

The specs for the 4412 list it's power handling at 150watts. I am at a bit of a loss as to why.

I currently have a pair of L150s and a pair of L100Ts, which list power handling at 300W and 400W respectively.

But the 4412 uses the same (other than color) 128H as the L150, and the same 104H-2 and 035Ti as the L100T, so it would seem like it's not a limitation of the drivers. Why would the power handling be cut in half relative to these other speakers?

[grumpy]

4412 =professional product ... target user more likely to understand specs.
L150(a)/L112 = consumer product ... target user brainwashed by industry marketing/specsmanship.

[Chris Brown]

4412 =professional product ... target user more likely to understand specs.
L150(a)/L112 = consumer product ... target user brainwashed by industry marketing/specsmanship.

Makes sense, thanks.

I hope that in practice their power handling will be roughly comparable to my existing speakers, because I can see myself putting much more than 150w into them. But really, I can't imagine they will let me down :)

[rdgrimes]

Power doesn't hurt speakers, people do that. (and poor quality sources/content)

Given a high quality music source and good clean amplification, you're safe with 1000WPC as long as you don't TRY to hurt them.

I'd guess you'd find a sweet spot at around 200-250WPC.

[Bobecca]

The specs for the 4412 list it's power handling at 150watts. I am at a bit of a loss as to why.



I currently have a pair of L150s and a pair of L100Ts, which list power handling at 300W and 400W respectively.

But the 4412 uses the same (other than color) 128H as the L150, and the same 104H-2 and 035Ti as the L100T, so it would seem like it's not a limitation of the drivers. Why would the power handling be cut in half relative to these other speakers?

Hello,

it is not power handling, it is power rating according to spec at 150 watts pink noise with a 6 dB crest factor for that nominal impedance load.
A use of a 300 watts amp with a 3 dB headroom means that one is on the safe side. Again, my understanding:)

[gferrell]

I have a pair of 4412a running 250w/ch with no problem. Very accurate sounding speakers in a small room.

[Chris Brown]

I use a Yamaha C-80 to run each of my two Yamaha P2201 amps in bridged mono. The amps do 230wpc in stereo but should be good for 600-700wpc+ in bridged mono.

When I was running my L150s from my Yamaha M-2 (Also similar to a P2201, but slightly better @ 240wpc) there were a few occasions where I bottomed out the 128H woofer. It sounded like someone using a wrist-rocket slingshot hitting a paper-plate at full force and it makes my heart skip a few beats every time. :crying:

I was thinking that maybe at only 230-240wpc, when the amp is being run so close to it's limits, maybe it has less than ideal control over the woofer. I haven't had it happen since I greatly increased my power by running the P2201s in bridged mono, but I'm not exactly trying to make it happen either. It's always something that is in the back of my mind when I listen loud. Since the 4412s use a 128H also, it will be interesting to see how they perform in a similar situation.

[pos]

If want to avoid damaging the 128H you should use a subsonic filter just under the bassreflex (or passive radiator) tuning.
Something like a But 18dB or 24dB/oct at 25 or 30Hz should do the trick.
It should reduce the bottoming out phenomenon you encountered, and also reduce distortion.

[DavidF]

I use a Yamaha C-80 to run each of my two Yamaha P2201 amps in bridged mono. The amps do 230wpc in stereo but should be good for 600-700wpc+ in bridged mono.

When I was running my L150s from my Yamaha M-2 (Also similar to a P2201, but slightly better @ 240wpc) there were a few occasions where I bottomed out the 128H woofer. It sounded like someone using a wrist-rocket slingshot hitting a paper-plate at full force and it makes my heart skip a few beats every time. :crying:

I was thinking that maybe at only 230-240wpc, when the amp is being run so close to it's limits, maybe it has less than ideal control over the woofer. I haven't had it happen since I greatly increased my power by running the P2201s in bridged mono, but I'm not exactly trying to make it happen either. It's always something that is in the back of my mind when I listen loud. Since the 4412s use a 128H also, it will be interesting to see how the perform in a similar situation.

Some back story on what you were listening to and at what sound levels would add to the story.

I looked back at the brochures and such I have on the L150 and 4412. With the L150 JBL was recommending amps that have 300 watt capacity and not really a specific power rating. The reason mentioned for the 300 watt amp was to provide sufficient power head room for momentary transients. For the 4412 they were referencing an actual power rating of 150 watts pink noise which I presume to mean a continuous power rating.

[Chris Brown]

Some back story on what you were listening to and at what sound levels would add to the story.

I used my L150s as mains in my home theater for about 2 years, ~10 years ago. The first time I ever had an 128H bottom out was while watching Apollo 13, during the Saturn V Blast-off scene. Other than that, one of my favorite genres of music is bands that straddle the line between electronic rock and Drum&Bass/dubstep. Bands like Pendulum or Example. I've had it happen while listening to those bands before. I listen pretty loud, but I can't say exactly how loud because unfortunately my cheap SPL meter doesn't take readings above 130dB (http://gotnorice.no-ip.org/130db.jpg) :(

[pos]

It is not *only* a matter of power handling (thermal).
It only takes 10W to exceed the Xmax of a 128H with a 10Hz signal in a typical 4412 box, without subsonic filter.
And signals at these kind of frequencies are plenty in modern movies soundtracks and electronic music...

[JuniorJBL]

I listen pretty loud, but I can't say exactly how loud because unfortunately my cheap SPL meter doesn't take readings above 130dB (http://gotnorice.no-ip.org/130db.jpg) :(

:eek:


At that rate, it wont be long before you cant hear anything anyways. If you do that for about 30 minutes a day for say 6 months, you will no longer need any audio gear cause you won't be able to hear.

But before you loose your hearing, get some pro gear with some 4645c's and turn it up. 12" home woofers are not for you.

[DavidF]

I used my L150s as mains in my home theater for about 2 years, ~10 years ago. The first time I ever had an 128H bottom out was while watching Apollo 13, during the Saturn V Blast-off scene. Other than that, one of my favorite genres of music is bands that straddle the line between electronic rock and Drum&Bass/dubstep. Bands like Pendulum or Example. I've had it happen while listening to those bands before. I listen pretty loud, but I can't say exactly how loud because unfortunately my cheap SPL meter doesn't take readings above 130dB (http://gotnorice.no-ip.org/130db.jpg) :(


It is not *only* a matter of power handling (thermal).
It only takes 10W to exceed the Xmax of a 128H with a 10Hz signal in a typical 4412 box, without subsonic filter.
And signals at these kind of frequencies are plenty in modern movies soundtracks and electronic music...

Yeah, that makes more sense on the nature of the low end issues. It's not so much about amp power as it is about combining low/very low bass with high sound levels which makes for extreme excursion. These models certainly encourage high-power use and offer up low distortion numbers but don't really fit this kind of application.

[gferrell]

If want to avoid damaging the 128H you should use a subsonic filter just under the bassreflex (or passive radiator) tuning.
Something like a But 18dB or 24dB/oct at 25 or 30Hz should do the trick.
It should reduce the bottoming out phenomenon you encountered, and also reduce distortion.

How do you make one of those?

[pos]

You need a piece of equipment between your source and your amplifer.
Some preamplifiers/receivers can do it, but most of the time it is not very flexible.

If you want to avoid going digital you can buy something like the Reckorn B2 (http://www.reckhorn.net/pages/active-x-over/b-2-active-bass-extension-subsonic.php?lang=EN), or if your are into DIY you can build one using the BX63a schematic (ignoring the LP filter, and using a lower Q for the HP filter to avoid the 6dB boost).

If you can stand a digital conversion, or if your source is digital to start with, then you can also use something like a DCX2496, or better still a minidsp openDRC, which will also let you do a lot of other things like manual EQ, phase linearization, DRC, loudness, ...

[Chris Brown]

get some pro gear with some 4645c's and turn it up. 12" home woofers are not for you.

The other side of the coin though, is that I'm operating in a bedroom that is approx 10' x 12'. Obviously the speakers aren't having to work as hard as they would if they were in a big living room with tall ceilings or something. 4 JBL 12" woofers (6 now!) have never really had much problems filling my tiny room with bass.

http://gotnorice.no-ip.org/4412.jpg

The 4412 speakers are lovely. Not so much as even a minor dent in any of the dust caps. No grills however. With speakers this beautiful, I can live without grills :)

I'm going to get them on their sides once I make a spacer to even out the height between my L150s and my L100ts, to give them an even-level surface to sit on their sides.

[JuniorJBL]

I really should not have imparted my views on your hearing.

Carry on.:dont-know:

[DavidF]

Well human hearing is not equally sensitive across the entire frequency range.

http://gotnorice.no-ip.org/714px-FletcherMunson_ELC.svg.png


The frequencies that human hearing is most sensitive to correspond nicely with the frequencies that I tend to EQ away. I like bass.

The other side of the coin though, is that I'm operating in a bedroom that is approx 10' x 12'. Obviously the speakers aren't having to work as hard as they would if they were in a big living room with tall ceilings or something. 4 JBL 12" woofers (6 now!) have never really had much problems filling my tiny room with bass.

http://gotnorice.no-ip.org/4412.jpg

The 4412 speakers are lovely. Not so much as even a minor dent in any of the dust caps. No grills however. With speakers this beautiful, I can live without grills :)

I'm going to get them on their sides once I make a spacer to even out the height between my L150s and my L100ts, to give them an even-level surface to sit on their sides.

Chris, your surround on the 4412 sure looks bad. If that is a hole then the bass response is compromised to a large extent. (Edit: nevermind, seems you are aware of the problem per your separate posting]

Your comment on high sensitivity of hearing vs high sound pressure levels does not really make sense.

[Chris Brown]

Chris, your surround on the 4412 sure looks bad. If that is a hole then the bass response is compromised to a large extent.

Yeah I'm not going to play them until I refoam them. I just have a few minor details to work out first: http://www.audioheritage.org/vbulletin/showthread.php?34089-128H-cone-diameter


Your comment on high sensitivity of hearing vs high sound pressure levels does not really make sense.

I've since removed most of that part of my post that you quoted, because I realized that the last thing I want to do is send this thread off into a tangent and start an argument that I don't really wish to have. If you look closer at my picture of my SPL meter, that is a peak reading, C weighted. If I had taken that measurement using A weighting I probably would not have even broken 110db, maybe not even 100db, because most of that was bass. A weighting hardly measures bass, in part because human hearing is much less sensitive to it relative to the frequencies closer to the human voice. I don't listen at 130db for extended periods, and certainly not when measured with A weighting. When I do listen loud, it's rarely for more than one song at a time. That's about all I've got to say about that.