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View Full Version : No Bass on a L96, help !



tofkitaff
10-30-2006, 04:12 AM
I am very happy with my L96, at home no problem at all, bass correctly balanced (not too much, not to low):cool:. I took them to make some listenning and comparaison for fun with other fan of materials and speakers. I do no know why, impossible to hear any (or nearly nothing) bass getting out of my L96... :biting: Here is a pic of placement :
http://img171.imageshack.us/img171/6127/image00005mr5.jpg

Do you see something wrong enough in the placement so that we could not hear any bass ? I need to be sure next time those L96 will be able to give all they can ! :bouncy:


Thanks guys,
ToFKitaFF!

Chas
10-30-2006, 09:38 AM
Possible you had the polarity reversed?

Robh3606
10-30-2006, 10:57 AM
Did you get them used?? I agree on a polarity check but you may also want to check just the woofers as well. I know when I have pulled woofers for a refoam I put them back in with the woofers out of phase:banghead:
That had me chasing my tail for a bit before I figured it out.

Rob:)

tofkitaff
10-30-2006, 01:54 PM
Indeed, I think you are right !!!!! BAck to home and polarity changed...they are back ! So, black goes on red and red goes on black !! :banghead: Is it my amplifier or my speakers that are not mounted correctly ???

Chas
10-30-2006, 03:01 PM
Probably victim of the old JBL polarity convention. Bo is our resident expert:p

toddalin
10-30-2006, 03:57 PM
Indeed, I think you are right !!!!! BAck to home and polarity changed...they are back ! So, black goes on red and red goes on black !! :banghead: Is it my amplifier or my speakers that are not mounted correctly ???

Seems to me that if both speakers were wired the same, polarity would have little to do with the overall bass response (unless you were trying to use them simultaneously with another pair).

Zilch
10-30-2006, 05:24 PM
...or with sub(s) of inverse polarity.

[Been there, done that.... :p ]

boputnam
10-30-2006, 06:53 PM
So, black goes on red and red goes on black !! :banghead: Is it my amplifier or my speaker...Whatever you choose to do, do it the same to both cabinets.

HOWEVER, when you are pairing vintage JBL with less-brands ( :p ) you need to ensure the LF's are firing OUT on (+) signal.

Hell, that being said, when you are pairing ANY cabinets, you need to ensure each element - LF, MF, HF, UHF - are all LIKE polarity. Otherwise, you get cancellations vs the additive effect you were (likely) seeking...

Thom
10-30-2006, 08:51 PM
you can't get them both wrong unless your playing them with soomething else. Its just a reference so you can have them the same. A flash light battery will tell you (no more flashlighlt batteries won't tall you better) It's usually pretty easy to tell by putting the system in mono. You should get a center chanel or as you move from one side to the other the sound should transition smoothly. If you're out of phase you won't get a center chanel and as you move from one side to the other at some point the sound will all of a sudden move from one speaker to the other it will never be from both. It's important to put it in mono because "effects" in the stereo may effect it. Trying to tell if your tweeter is in phase doesn't seem to be nearly as easy. I think maybe because you may be comparing different amounts of "out of phase" With a little practice you will pick up when your left and right are out of phase when your not looking for it. Another way, again in mono, with some material with some base listen then turn the ballance control if you have more base with both speakers on they are in phase if you have more base with just one speaker they are out of phase. but it's in phase with each other or out of phase with each other. I wasn't there and I don't know what the equipment is or what the rooms look like but that can all have an effect and if there is a sub (just thought of that) they have to be in phase with it also.

LRBacon
11-04-2006, 09:11 AM
Did you get them used?? I agree on a polarity check but you may also want to check just the woofers as well. I know when I have pulled woofers for a refoam I put them back in with the woofers out of phase:banghead:
That had me chasing my tail for a bit before I figured it out.

Rob:)

I had bought a pair of L110s off of ePay a few months ago. I had them hooked up properly and had been listening to them for sometime but the bass sounded weak. They had been refoamed, so I pulled the woofers and low and behold on one of them the wires from the crossover network were reversed, green/black to positive(red) and green to black (negative) I corrected them and put the woofers back in the cabinets and fired them up and the bass was back.

Larry

Rolf
11-04-2006, 09:57 PM
Polarity errors are a mistake we sometimes do, and the last thing we check because we know it sooo well, and don't believe we actually make that mistake our self.

I speak from experience!:o:

NancyJ
11-04-2006, 10:10 PM
also.. maybe check to see if
you have the correct Ohms for for your driver compliment . well/ 8 ohm or 16 ohm ect? the voice coils are so important.

Wait. the crosovers might be belly up caps... I lost a very a rare pair of speakers due to lost cap.

get a meter and test

or I have 5 bucks for you? shame on me.?

tofkitaff
11-09-2006, 04:26 AM
I had bought a pair of L110s off of ePay a few months ago. I had them hooked up properly and had been listening to them for sometime but the bass sounded weak. They had been refoamed, so I pulled the woofers and low and behold on one of them the wires from the crossover network were reversed, green/black to positive(red) and green to black (negative) I corrected them and put the woofers back in the cabinets and fired them up and the bass was back.

Larry

So, I definitely need to check inside the speakers... it will be a great and new experience for me, so affraid to break something..:o:

All i know is that normally, they have been reviewed bzefore I buy them.. but it is what the seller told me...

Thanks anyway to all of you for your usefull comments, but the more I learn about speakers, the less I undesrtand as it can become complex...


ToFKiTaFF!