Can JBL E250 go 30Hz or below? [Archive] - Audio & Video Forums

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AVJunior
01-23-2005, 10:58 PM
Any one heard of this Sub?

lazyhaze
01-24-2005, 01:05 AM
Any one heard of this Sub?

i have one of these subs in my room right now, you can buy them at Best Buy, which is good cause then you can do a home demo, and return it if you don't like it. the E250p doesn't go very low, it will make sounds at 30 Hz and below but there is a huge dropoff in sound pressure level (SPL) once you go below 35 Hz. by the time you get down to 30 Hz the sub is very quiet compared to any other frequencies present in your system. i have a tone generator and tested the sub with a SPL meter sitting in my normal listening position. i also find that the amplifier is pretty weak on this sub, i need to have the volume at around 2 o'clock on the Gain knob to have it match the rest of my system. pushing an amp that hard usually leads to high distortion with a sub.

hope that helps

console
01-24-2005, 05:18 AM
I have a pair of JBL L100A, the last version - I have heard that it can go below 28Hz without major drop, and that the A model use the best 12" JBL ever made. It sounds like it goers very low to my ears ( and my windows ), but I have no equipment to measure. What do you think - do you know any thing on the L100A ?

console
01-24-2005, 05:47 AM
i have one of these subs in my room right now, you can buy them at Best Buy, which is good cause then you can do a home demo, and return it if you don't like it. the E250p doesn't go very low, it will make sounds at 30 Hz and below but there is a huge dropoff in sound pressure level (SPL) once you go below 35 Hz. by the time you get down to 30 Hz the sub is very quiet compared to any other frequencies present in your system. i have a tone generator and tested the sub with a SPL meter sitting in my normal listening position. i also find that the amplifier is pretty weak on this sub, i need to have the volume at around 2 o'clock on the Gain knob to have it match the rest of my system. pushing an amp that hard usually leads to high distortion with a sub.

hope that helps


I have a pair of JBL L100A, the last version - I have heard that it can go below 28Hz without major drop, and that the A model use the best 12" JBL ever made. It sounds like it goers very low to my ears ( and my windows ), but I have no equipment to measure. What do you think - do you know any thing on the L100A ?

console
01-24-2005, 07:25 AM
i have one of these subs in my room right now, you can buy them at Best Buy, which is good cause then you can do a home demo, and return it if you don't like it. the E250p doesn't go very low, it will make sounds at 30 Hz and below but there is a huge dropoff in sound pressure level (SPL) once you go below 35 Hz. by the time you get down to 30 Hz the sub is very quiet compared to any other frequencies present in your system. i have a tone generator and tested the sub with a SPL meter sitting in my normal listening position. i also find that the amplifier is pretty weak on this sub, i need to have the volume at around 2 o'clock on the Gain knob to have it match the rest of my system. pushing an amp that hard usually leads to high distortion with a sub.

hope that helps


Just a little detail. The human ear begins to hear low freq from about 30Hz ( according to the experts ) ), so freq at 30Hz and propably up to 40Hz you will have a rising curve of hearing, SO when you experience the above, what you realy experience is that your human ear will hear less and less till it cant hear the freq below 30Hz - but the sub may very well reproduce the sound below 30Hz - but you cant realy hear it, and it sounds like the sub drops..

What you CAN hear is the noice from single glass windows when they wibrate and make the frame wibrate too.

console
01-24-2005, 07:36 AM
i have one of these subs in my room right now, you can buy them at Best Buy, which is good cause then you can do a home demo, and return it if you don't like it. the E250p doesn't go very low, it will make sounds at 30 Hz and below but there is a huge dropoff in sound pressure level (SPL) once you go below 35 Hz. by the time you get down to 30 Hz the sub is very quiet compared to any other frequencies present in your system. i have a tone generator and tested the sub with a SPL meter sitting in my normal listening position. i also find that the amplifier is pretty weak on this sub, i need to have the volume at around 2 o'clock on the Gain knob to have it match the rest of my system. pushing an amp that hard usually leads to high distortion with a sub.

hope that helps

Forgot to mention that you need at least 150 W pr channel to drive the subs correctly on transients.

royphil345
01-24-2005, 09:37 AM
The position of the subwoofer volume control necessary to match the other speakers has nothing to do with how powerful the sub's amp is. With a 250 watt sub, you should be able to match the level of your other speakers at the full volume most AV receivers are capable of. (Unless your crossovers are set very high and your sub has to do most of the work) If a 250 watt sub can't do that, then I'd classify it as underpowered. I haven't heard of this or any other JBL sub being underpowered. Sure, some of the previous models tended to burn out their amps in about a month. Think that should be taken care of now.

Why in the world would you need at least 150 watts to drive a powered sub?

I've only heard the JBL sub at Best Buy. It sounded tight and punchy. Didn't seem to go all that low, but it's really hard to tell much about any component in Best Buy's listening areas. Before buying, I'd also go to Circuit City and audition the Sony SA-WX700, which I think sounds just as good and goes a bit lower for a little less $. (web prices) Don't bother listening to the boomy, single-woofer crap Sony subs at Best Buy. That's not what I'm talking about.

Sir Terrence the Terrible
01-24-2005, 12:50 PM
{quote]Just a little detail. The human ear begins to hear low freq from about 30Hz ( according to the experts ) ), so freq at 30Hz and propably up to 40Hz you will have a rising curve of hearing, SO when you experience the above, what you realy experience is that your human ear will hear less and less till it cant hear the freq below 30Hz - but the sub may very well reproduce the sound below 30Hz - but you cant realy hear it, and it sounds like the sub drops..

What you CAN hear is the noice from single glass windows when they wibrate and make the frame wibrate too.[/quote]

Actually our ears ability to hear low frequecies drops off at 40hz. At that point bass is tactile more than audible. A good sub will smoothly make the transition for audible to tactile without any noticeable dropoff in amplitude.


I have a pair of JBL L100A, the last version - I have heard that it can go below 28Hz without major drop, and that the A model use the best 12" JBL ever made. It sounds like it goers very low to my ears ( and my windows ), but I have no equipment to measure. What do you think - do you know any thing on the L100A ?

My expirence with the L100 suggests that it does NOT have much output below 35hz. However it has very fat bass down to about 40hz or slightly below.

In terms of the original poster question about the sub lazyhaze has got it right on this one.

E-Stat
01-24-2005, 01:27 PM
Actually our ears ability to hear low frequecies drops off at 40hz. At that point bass is tactile more than audible.
Indeed. The 32 hz fundamental from a pipe organ is sensed more than heard. I can feel it from the foyer of the church.


My expirence with the L100 suggests that it does NOT have much output below 35hz. However it has very fat bass down to about 40hz or slightly below.
JBL's specs support that notion. Here's a link to the pro version of the Century, the 4311:

<a href="http://www.lansingheritage.org/images/jbl/specs/pro-speakers/1973-4311/page03.jpg">JBL Specs</a href>

rw

lazyhaze
01-25-2005, 03:12 AM
@console...while what you say may be true about hearing low frequencies, the measurements i did were done with a meter, not my ears. higher quality subs will not experience such a dramatic dropoff until a lower frequency.

@royphil...i think jbl is probably exaggerating the power ratings for this sub. if i have to put the volume at close to 100% to match my other speakers than the subwoofer doesn't have much power in reserve for a more powerful system. any amp being pushed that hard is going to be clipping very often and probably has huge THD. 250 watts is a huge amount of power, the sub should be absolutely deafening if that is the true rating. i am an electrical engineering student and it is depressing how badly many manufacturers massage their numbers until they get nice high ratings to impress the big box audio crowd. as for the Sony WX-700, i have one on order now because i want to compare it directly to the JBL before i return it. i have heard many good recommendations for it on this board, from you and many others. it is probably also not the 250 watts it claims to be but if it is even half that it is still by far enough power. i have high hopes for the WX-700 as it is an acoustic suspension (sealed) sub, which is supposedly better for music according to what i have read on this board. fortunately i can do a home audition to test this out.

console
01-25-2005, 01:50 PM
@console...while what you say may be true about hearing low frequencies, the measurements i did were done with a meter, not my ears. higher quality subs will not experience such a dramatic dropoff until a lower frequency.

@royphil...i think jbl is probably exaggerating the power ratings for this sub. if i have to put the volume at close to 100% to match my other speakers than the subwoofer doesn't have much power in reserve for a more powerful system. any amp being pushed that hard is going to be clipping very often and probably has huge THD. 250 watts is a huge amount of power, the sub should be absolutely deafening if that is the true rating. i am an electrical engineering student and it is depressing how badly many manufacturers massage their numbers until they get nice high ratings to impress the big box audio crowd. as for the Sony WX-700, i have one on order now because i want to compare it directly to the JBL before i return it. i have heard many good recommendations for it on this board, from you and many others. it is probably also not the 250 watts it claims to be but if it is even half that it is still by far enough power. i have high hopes for the WX-700 as it is an acoustic suspension (sealed) sub, which is supposedly better for music according to what i have read on this board. fortunately i can do a home audition to test this out.


I havnt heard the 250, but I can tell you my experience with the L100. I have a modest Technics SU-610 amplifier 35W pr. channel ( will look for a good old Marantz soon ). The volume scale is 1-10. At 1.5 my single glass windows starts to vibrate, ( so its not the sound preasure which make the windows vibrate - but the freq it self ). at 2 its loud, 3 is party level, and 4 I did test once but Im afraid the windows will shake out of its frame playing some of the modern tracks. Its not bass I miss at any sound level ! And perhaps some instrument can measure a drop - but I cant hear it. There are some things in this world which simply cant be measured by an instrument for quality, and speakers is one of them.

So my JBLs has a very high degree of responce - which I think most of the old JBLs had, since the consept was to make speakers for small to medium sized consert rooms where only old and low power equipment was available. Comparing to my "old" 3-way speakers, I get about 60% more sound preasure on the same watts.

MSC Eng. Electronics 1986 / MBA

console
01-25-2005, 03:13 PM
Indeed. The 32 hz fundamental from a pipe organ is sensed more than heard. I can feel it from the foyer of the church.


JBL's specs support that notion. Here's a link to the pro version of the Century, the 4311:

<a href="http://www.lansingheritage.org/images/jbl/specs/pro-speakers/1973-4311/page03.jpg">JBL Specs</a href>

rw

@E-Stat:

Thanks for the link !

AVJunior
01-25-2005, 11:18 PM
how bout the wharfedale powercube? anyone heard of it? does it go low and loud enough?

lazyhaze
01-27-2005, 05:05 PM
the Sony WX-V700 arrived today. i was very excited about this sub. i compared it to the JBL E250p using A/B testing with music and movies, and measuring the frequency response with my sound meter. Both subs were measured from the same location, on a piece of wood in the middle of my couch, which is my ideal listening spot, at a distance of 1 meter. I calibrated both subs with my system using my receiver's (Yamaha RX-V640) test tones. I set both sub's to be 4 db's higher than the rest of my speakers. This resulted in both the Sony and JBL's volume knob to be at about 2 o'clock.

Sound Meter Test: On paper they measured nearly identical, with both experiencing a 3dB drop per Hz below 38 Hz. The JBL performed slightly better at 32 Hz and below, being on average about 2 dB higher than the sony. I was a bit surprised that the Sony was so comparable at the lower frequencies, as the JBL has a 12" driver compared to the Sony's dual 10"s. This is probably due to the Sony's sealed design, which I believe results in lower extension than ported subs.

Listening tests: Setup
For the music and movie tests i placed both subs side by side on the wall to the left of my couch, which was the best bass location i heard using the crawl test. I A/B'd the subs by switching one on and the other off, with both being connected using a y-splitter from my subout. In case one sub was in a slightly better position than the other, i switched the subs location part way through the test, and repeated the material. This didn't cause any noticeable difference. The polarity was set to 180 degees for both subs, as this sounded better in that location. The crossovers for music was set to 80 Hz (hard to tell with no labels on the knobs). For movies the crossovers were set to max.

Music test: I had read that sealed subs are much tighter for music, and expected the Sony to be superior in this test. However, I found the JBL to be much tighter than the Sony and with a much fuller, richer sound. The Sony could blast as loud as the JBL without too much trouble, but seemed to have a mass of bass, whereas the JBL could carry a bass line and have distinct drum kicks as well. When listening to house music, the Sony was noticeably behind the beat on the bass drum, while the JBL seemed to be right on time. Listening to the Strokes, an alternative band, some bass notes seemed way louder with the Sony, while the JBL had a smoother response. This was especially confusing as their theoretical response should have been the same. This was noticed in both locations for the Sony sub, so i don't believe the room was responsible.

Movies: In Underworld, i watched the gunfight scene in the subway. Each gunshot could be heard distinctly with the JBL, while the Sony had the sounds melting into each other. The Sony always seemed to have a sound last half a second or so longer than it should have, like a trail. At high volumes the Sony sub cabinet resonated, which was extremely annoying.

After i had boxed the Sony back up, i tried using the y-splitter with the JBL's right and left inputs and this resulted in an increase in sound volume, perhaps explaining why i felt the JBL was underpowered prior to the side-by-side comparisions. Both the Sony WX-V700 and the JBL E250p were a vast improvement over my Sony SA-WM20, which is the sub i am trying to replace.

On paper the two appear identical, so the listening tests are purely my own opinion. When I recorded the values for the Sound meter test, i made some graphs in Excel. If someone would like to see them I can try to post them.

So the JBL E250P is my current champion, I paid 750 canadian for it at best buy, with the intention of returning it since it can be ordered from the states for far less than that, about $400 shipped and with tax. I keep coming across recommendations for the Dayton 10" sub from parts express, does anyone have any experience with both of these subwoofers? Any input would be appreciated.