Jbl Sub1500 15" Subwoofer 4 Ohm

[MJC]

I was just reading through the sub1500 manual. I'm glad I had enough sense to use 10ga, being I bought a 50ft roll and cut it in half and used each half for each sub. Falls in line with their wire chart, and even more so being I'm using a K2 amp that outputs 800w instead of the LE-1's 700w. And the K2 is set to almost max.
Revel's decision to discontiue the 1500 really did make a bargain for all of us that grabed them for $250. And in a review I read they outperformed the Velodyne sub that was available at the time of the review.

http://cgi.ebay.com/ws/eBayISAPI.dll...MEWA%3AIT&rd=1


Oh look.... here's one now, and it even comes with that killer amp! I realize this is a bit steep for those of us who were lucky enough to get the Sub1500s at fire sale prices, but this is really quite the deal. I wish I had a few extra bucks lying around.

Widget

[Mr. Widget]

This thread has been idle long enough!

I have been using Sub1500s since March 2004... during that time I tried 1.5 cu ft sealed boxes and ported 5 cu ft boxes. In my large bass hungry room I found the big ported numbers to be preferable. For the vast majority of their life I have used these wonderful woofers in my HT system and the results are simply staggering. The sound of a building coming down or a mid-air collision is quite enveloping as the room pressurizes with the impact of the subsonic noise.

More recently I have also been using them to augment my stereo system. In critical listening I have found the group delay to be quite apparent. It makes the deep bass sound like it is coming from some quite distant source that is almost echo like... this effect is awesome for the movies, but rather disturbing when it is coming from the lower notes of the piano.

Most likely I will build a pair of 2.5-3.0 cu ft sealed boxes for a pair to be used with music and continue using another pair in the big ported boxes. For now I am using the patented Zilch magic port stoppers (otherwise know as a 4" plumber's plug). Here are plots comparing the frequency response change and the group delay changes between the two. Realize these are simulations and do not show any room gain.

Widget

[Lancer]

For the vast majority of their life I have used these wonderful woofers in my HT system and the results are simply staggering. The sound of a building coming down or a mid-air collision is quite enveloping as the room pressurizes with the impact of the subsonic noise.

More recently I have also been using them to augment my stereo system. In critical listening I have found the group delay to be quite apparent. It makes the deep bass sound like it is coming from some quite distant source that is almost echo like... this effect is awesome for the movies, but rather disturbing when it is coming from the lower notes of the piano.

OMG! You mean I wasn't full of shit and blowing smoke up everyone's ass all these years???

[mikebake]

Thank God, someone has lassoed this dinosaur thread from their SUV and pulled it from the tar pit. Ahhh, the love affair continues.
Mine haven't even stretched their legs from outta the box much yet, so by the time ya'll are tired of 'em, I'll be waxing rhapsodic.
Anyway, it just ain't right in my view: a driver is like a muscle and needs to be put to good use on a regular basis, otherwise what good is it? Seeing a shelf full of fine "vintage" drivers sitting mute leaves me with a sad feeling, like seeing a champ mothballed.

[Mr. Widget]

For the vast majority of their life I have used these wonderful woofers in my HT system and the results are simply staggering. The sound of a building coming down or a mid-air collision is quite enveloping as the room pressurizes with the impact of the subsonic noise.

More recently I have also been using them to augment my stereo system. In critical listening I have found the group delay to be quite apparent. It makes the deep bass sound like it is coming from some quite distant source that is almost echo like... this effect is awesome for the movies, but rather disturbing when it is coming from the lower notes of the piano.

OMG! You mean I wasn't full of shit and blowing smoke up everyone's ass all these years???

Sure you were! Just not about massive group delay.


BTW: Did you ever mention that it could be a useful tool? I don't seem to remember ever reading where someone thought it a beneficial acoustic phenomena... in my HT it is a very neat effect. I did read an interview with John Meyer years ago where he described installing some massive low distortion subs in a San Francisco theater back during the release of Apocalypse Now. While his subs were lower distortion at greater SPL, the big Altecs sounded BIGGER... he didn't attribute it to group delay, but that may have been part of it along with a healthy increase in second harmonic distortion... sometimes maybe a bit of distortion is a nice thing. Tubes anyone?

Widget

[mikebake]

.. sometimes maybe a bit of distortion is a nice thing. Tubes anyone?

Widget

Been widely discussed without, of course, resolution elsewhere. My ponderings on the question for the last few years is that there can be some pleasantly received distortion, in different forms.

[speakerdave]

Actually, I do remember "Giskard" mentioning the group delay penalty when using the big box with ports (or any other bass extension strategy), but it is simply too tedious to go back and find it.

Despite previous claims that there is no connection between group delay and real time in playback, I do not think having subwoofers back in the corners behind the speakers (as I have seen in many system photos in these forums) is a very good idea. I'll refer to Drew's suggestion that subwoofers be centered between the main speakers and forward of their plane if possible. Can't hurt to try it. I believe that JBL is now suggesting midway along the sidewalls now in some of their literature.

Anyway, I will very soon be beginning my own experiments thanks to the generosity of one of our forum Wizards who had some surplus boxes.

David

[Mr. Widget]

Actually, I do remember "Giskard" mentioning the group delay penalty when using the big box with ports...

Absolutely! I agreed in principle at the time too, but didn't really have a preference one way or the other until I started to really listen critically in a two channel stereo scenario.

What I was trying to point out in my post above was that for movies, the most "accurate" sound may not be the most desirable. John Meyer found this out in his demo where his theoretically superior speakers were not universally accepted and seemed unimpressive in comparison to the "less accurate" industry standard. In my case, I prefer the "massively large" sound that is created by this less than ideal tuning... but only in the realm of LFE. For music, plugging the ports makes a huge improvement making the sound much more integrated.

I am sure there would be people that prefer the dryer sound for LFE as well and yet others that would like the "massive" sound for music... it is all good!


Widget

[Lancer]

the most "accurate" sound may not be the most desirable.

Evidently so if folks here are spec'ing E120's for home hi-fi midbass transducers...

[Mr. Widget]

Evidently so if folks here are spec'ing E120's for home hi-fi midbass transducers...

Did I do that?

If I did, I was wrong... if someone else made that recommendation, I bet it is a good idea...


Widget

[Lancer]

if someone else made that recommendation, I bet it is a good idea...

"Right..." - Dr. Evil

[spkrman57]

But I have the consolation prize: 2242 in 9 cubic ft cabinets. They are finally starting to break in some from regular playing.

I like when folks come over and start looking around when really "LOW" notes play on the audio system that they can't hear, but definitely feel.

I should have been more attentive when the sub1500's were available, I would have liked a pair to try out.

Maybe when Baker gets tired of his sitting around, I'll have to catch him at a weak moment and buy them off him!!!!!



Ron

[Lancer]

Why are his sitting around? He has two boxes for them right now. They can be run sealed or ported as desired.

[spkrman57]

"Mine haven't even stretched their legs from outta the box much yet, so by the time ya'll are tired of 'em, I'll be waxing rhapsodic."


Mike, send them to me to give them some actual run time!!!!


Ron

[Lancer]

Oh. Maybe he's still looking for something to drive them with.