Best 15 inch JBL Subwoofer?

[Robh3606]

I realize that you don't run into this sort of thing because you primarily watch those fine Merchant Ivory films , but if you pop in a Terminator film,

Hello Widget

Arnold the actor is my Sci Fi hero. I have the limited edition THX version of T2. I listen to a decent amount of movies and am a real Sci Fi buff. Pearl Harbor is a kicker as well especially during the attack.

I ran an experiment on the 4344's last night. I used the old Telarc 1812 Oveture on CD as the test track. No high pass filter in place. Took out the digital peak reading SPL meter. Topped out at 112.8 db peak on the cannon shots. Those are wideband blasts with lots of energy so I don't know where the peak was but I suspect it's in the upper part of the woofers range or even into the 2122's range where the sharp crack is. Obviously lots of cone motion.

I ran another one using my surround system with the newer SACD of the 1812. Didn't use the SPL meter just keep going until the amp for the B380 clipped. Have a straped Crown 150A so I have a little over 300 watts available.

Damn that was fun!!

Best I can figure is the rooms are bigger than mine and they must be using more power. With the 4344's I looked like I was close but didn't push it any higher even though I still had some juice left in the amp driving the 2235's.

Both of these experiments were louder than I would normally listen at so I guess I am a movie whimp with respect to the volume control. If my listening habits are at a lower SPL level than others that could certainly account as to why I have not had any "ringers" here.

Rob

[Chas]

That's the problem with having an older forum... so many of these topics will be gone over and over again.

Widget

Yeah, but isn't it nice to reminisce?

[Ian Mackenzie]

Hello Widget

Arnold the actor is my Sci Fi hero. I have the limited edition THX version of T2. I listen to a decent amount of movies and am a real Sci Fi buff. Pearl Harbor is a kicker as well especially during the attack.

I ran an experiment on the 4344's last night. I used the old Telarc 1812 Oveture on CD as the test track. No high pass filter in place. Took out the digital peak reading SPL meter. Topped out at 112.8 db peak on the cannon shots. Those are wideband blasts with lots of energy so I don't know where the peak was but I suspect it's in the upper part of the woofers range or even into the 2122's range where the sharp crack is. Obviously lots of cone motion.

I ran another one using my surround system with the newer SACD of the 1812. Didn't use the SPL meter just keep going until the amp for the B380 clipped. Have a straped Crown 150A so I have a little over 300 watts available.

Damn that was fun!!

Best I can figure is the rooms are bigger than mine and they must be using more power. With the 4344's I looked like I was close but didn't push it any higher even though I still had some juice left in the amp driving the 2235's.

Both of these experiments were louder than I would normally listen at so I guess I am a movie whimp with respect to the volume control. If my listening habits are at a lower SPL level than others that could certainly account as to why I have not had any "ringers" here.

Rob

Hi Rob,

I'll bet that was fun.

I have never slapped a 2235 in 25 years but I did end up using four 2235s in larger rooms running a flame Linear 700B with 700 watts a side.(no it never blew up) crossed over at 300 hertz.


But running the driver below say 80 hertz with that amount of power as dedicated sub is a different matter.

To illustrate max power output at low frequencies in terms of cone X max to the uninitiated I have attached a Bassbox sim of the 2235H ( green and cyan) in 5 cu ft 3 tuned to 32 and 28 hertz respectively. The reduction in power output at 32 hert is significant. With a high pass filter at 30 hertz the 32 hertz tuning would make quite a robust sub.

Tuned a bit lower to 28 hertz and we now see the trade off of power output versus extension with 7 db less output @ 32 hertz. Tuned even lower (Red) to 26 hertz its the best part of 3 db less power output at 32 hertz than the 28 hertz tuning.

None of this is rocket science but if you want high output below 30 hertz with low distortion if comes down to displacement and lots of watts.

The thing to know is when/what is the requirement for sub 30 hertz output and is that worth sacrificing for much higher output above 30 hertz.

I think the answer is no if you use your sub for normal music (and use a high pass filter). Best to get a real dedicated ELF sub for the home cinema application. Not many subs actually do that properly. The BagEnd audio http://ralaudio.com/bag-end-i12-pro-...ncy-p-490.html and Wise Pro thunder http://www.smr-home-theatre.org/ces2.../page_12.shtml would be on my list

[Mr. Widget]

Best I can figure is the rooms are bigger than mine and they must be using more power.

Possibly SPL meter mic position in the room too... if your meter is in the listening position and you sit near the rear wall, you could be getting 10dB of gain from sitting in a major room mode.


Widget

[4313B]

Possibly SPL meter mic position in the room too... if your meter is in the listening position and you sit near the rear wall, you could be getting 10dB of gain from sitting in a major room mode.

Exactly. Same goes with the guys sitting in a null cranking up the sub output until something blows.

[Robh3606]

Possibly SPL meter mic position in the room too... if your meter is in the listening position and you sit near the rear wall, you could be getting 10dB of gain from sitting in a major room mode.

True but why would you have your listening position in a room mode hot spot?? Sort of defeats all the rules about proper room set-up and speaker placement unless you like one note bass.

Rob

[Mr. Widget]

True but why would you have your listening position in a room mode hot spot?? Sort of defeats all the rules about proper room set-up and speaker placement unless you like one note bass.

I wasn't suggesting that it was a good idea. I was suggesting that perhaps due to your smaller listening space you may be sitting near the rear wall where there would be a bass mode with enough gain that you may actually be driving your system less hard than you think.

While many people find themselves in just such a situation, I agree with you that the quality of bass under these conditions is really far from ideal.


Widget

[Jakob]

I don't know if the ME150HS is still available from harman and therefore an option. But if it is I would really recomend it to anyone. I've read somewhere here that it is considered bass-shy by some, but compared to what and in what way? My pair blows away the LE14's in my 250ti's in every way except for maybe the sub 30Hz area.