LSI/FX Question

Foz · February 2006

I just hooked up my new LSI/FX speakers. I put them in "Bi" mode for music and notice that only one woofer and one tweeter is active in each speaker. Is that the way they are supposed to be?

Thanks

RoosterD · February 2006

Foz wrote:

I just hooked up my new LSI/FX speakers. I put them in "Bi" mode for music and notice that only one woofer and one tweeter is active in each speaker. Is that the way they are supposed to be?

Thanks

Not from what I've seen with mine. The only thing that should change is polarity? I think. You switch it to "Di" when they are at your sides when seated, and "Bi" when they are setup behind you seated.

RoosterD · February 2006

Foz wrote:

I just hooked up my new LSI/FX speakers. I put them in "Bi" mode for music and notice that only one woofer and one tweeter is active in each speaker. Is that the way they are supposed to be?

Thanks

Not from what I've seen with mine. The only thing that should change is polarity? I think. You should definitely get sound out of all the speakers though. You switch it to "Di" when they are at your sides when seated, and "Bi" when they are setup behind you seated.

Foz · February 2006

Thanks RoosterD,

When I put my ear to one side I hear the sound. When I listen to the other side they are dead. Both speakers are the same way. Could I have purchased 2 defective speakers? That seems to be against the odds. But I wouldn't think they would be designed to just fire on half the speaker for music?

RoosterD · February 2006

Foz wrote:

Thanks RoosterD,

When I put my ear to one side I hear the sound. When I listen to the other side they are dead. Both speakers are the same way. Could I have purchased 2 defective speakers? That seems to be against the odds. But I wouldn't think they would be designed to just fire on half the speaker for music?

I would double check that the Pos/Neg terminals are connected to each other by the gold bar in the back. This isn't meant to be condescending, but if it is connected, then you may want to have that looked at. You should have sound out of all 4 speakers. If it has sound out of all 4 when set to "Di" then it would be an issue with that switch.

Foz · February 2006

The gold bars are there. I don't have sound out of all 4 speakers in either mode. I notice they are "right channel" and "left channel". If I had gotten that wrong then all the sound would be directed to the back of the room. Since the speakers that work face the front it still makes me think it's normal that the sound is coming from one direction. You're a big help and I'm not trying to frustrate you but have you put your ear close to your speakers? I'd hate to send these back only to have them tell me they are working fine. But.......something seems very wrong here.

Foz · February 2006

Do the gold bars send the signal to the other speakers in the box? I thought they were for those who didn't bi-wire the woofer and the tweeter.

Foz · February 2006

Well, here's the answer I got from my dealer who seems like an excellent buisnessman in all respects. Here is what another of his customers had to say:

<<FYI: I just got off the phone with Polk Audio, who explained to me that this is normal and intentional and a result of the comb filter they use in this speaker. As it happens, the phenomenon disappears as the distance from the speaker grows, and is (and I can attest to this) very apparent if you are within a couple of feet from the speaker. Apparently, this speaker is acting normal.>>

RoosterD, what do you think of that? Ever heard of this with the FX's?

RoosterD · February 2006

Foz wrote:

Well, here's the answer I got from my dealer who seems like an excellent buisnessman in all respects. Here is what another of his customers had to say:

<<FYI: I just got off the phone with Polk Audio, who explained to me that this is normal and intentional and a result of the comb filter they use in this speaker. As it happens, the phenomenon disappears as the distance from the speaker grows, and is (and I can attest to this) very apparent if you are within a couple of feet from the speaker. Apparently, this speaker is acting normal.>>

RoosterD, what do you think of that? Ever heard of this with the FX's?

I can't wait to get home and check this out. I had a similar experience with the LSiC drivers. I couldn't hear anything out of the left driver, but could hear fine out of the right. After contacting Polk, I was told that it was designed that way in order for a better listening experience from the sides of the speaker. In example, low frequency would only come out of the left driver, and mid to high out of the right. It sounds weird, but maybe that's a similar thing with the FX's? I'll let you know what I find with mine later on tonight!

kmartin971 · February 2006

Run a sound test on the surrounds. I had the same problem and had to replace the crossover.

Hook em up to the front channels on low power they should sound identical. If not the something needs to be replaced.

Foz · February 2006

kmartin,

I usually think of crossovers being used between the woofer and tweeter. Is there a crossover between one side and the other in the FX?

Thanks

cmy330go · February 2006

I think what you are hearing is the effects of the cascade crossover. the one woofer only carries frequencies below 200hz. This can make it seem as though it is not working. If you put your ears right up to the tweeters you should be able to here both equally.

ezc · February 2006

cmy330go is right, the cascade crossover will make it seem like only one low driver is working, send the speaker somthing with lots of lows & Im almost sure you will hear both low drivers, with the mid low still being louder. The same for the LSiC many feel one driver is dead, but it is designed that way, If you dont like the C that way try & using a LSi9 xover. I have done that to mine about 2 years ago & have been very happy!

cmy330go · February 2006

ezc wrote:

If you dont like the C that way try & using a LSi9 xover. I have done that to mine about 2 years ago & have been very happy!

Can someone explain why this would change anything? According to Polk's specs the crossovers for the 9s and C are the same in terms of frequencies and slopes. Just curious.

kmartin971 · February 2006

The crossover in the FXs connection both tweeters and woofers, in addition to the dipole switch. Easy way to find out in remove the crossover and look for physical damage. When I pulle mine off is was ovious that it was damaged.

kmartin971 · February 2006

Using the 9 instead of the C will add more more bass to the center. That's it.

Foz · February 2006

kmartin,

Is it your opinion/experience, that on a proper working lsi/fx both sides of the speaker should sound the same? And, have you ever heard about a "comb filter" inside the lsi/fx?

Thanks

kmartin971 · February 2006

Its not a comb filter its a crossover. When played as a surround all speaker will not work at all times. What I am saying is if you hooked them up as front left and right channel (not to the surround connections) speakers set to bipole each speaker will play all frequencies and should sound identical (all tweeters and woofers will operate at the same time). This is a very easy way so see if the speaker is functioning properly.

Foz · February 2006

Thanks kmartin,

I hooked up 1 to the front channel and it still sounded loud on one half and dead on the other. I guess I need to figure out how to get to the crossovers. It's hard to believe my luck. Both speakers are the same way.

kmartin971 · February 2006

Its easy to access the crossover. The crossover is the gold connections on the back. Remove the screws and the entire crossover comes out easily. Their are two copper coils. On the one I had one was barely hanging on. I had the same problem. If it looks bad. The rick will be removing the croosover wires from the dipole switch. I can explain this later but first find over if their is any physcial damage to the crossover.

cmy330go · February 2006

That is normal.....One side will sound quieter than the other because one side is only carrying low bass frequencies while the other side is carrying midrange (which is much more pronounced). Mine sound the same way. The side with the switch sounds louder than the other. (yours may be reversed from that)

Don't worry your speakers are working fine.

kmartin971 · February 2006

Key is when you hook em upto the front channels do not focus on sound from left vs right. Both surrounds should sound the same. cmy is correct in the post above. If they sound the same odds are their is nothing wrong.

When I had problem their was a noticable difference between the two speakers. One woofer was not getting any power and you could noticebly tell that the speaker was not producing a mid range frequency.

Foz · February 2006

Ok, I used Avia and put "white noise" on the speakers. I still couldn't detect any sound from one side. I'm going to give this up if you guys think they are acting normal. They are brand new out of the box. You'd think they would be fine.

Thanks for all the comments!!!!!!

kmartin971 · February 2006

Mine were new out of the box and the crossover looked like someone hit it with a hammer! Call a Polk rep and have them help you. Thats how I identifed my problem.

If they do not sound right to you or when hooked upto a front channel they are still not producing sound I bet their is a problem with the woofr itself or the crossover.

cmy330go · February 2006

I am 99.9% positive that you are just hearing the effects of the crossover. If you can't rest on it and HAVE to prove to yourself that both drivers are working I would recommend the following:

Find a bassy piece of material. No need to crank it, just enough to comfortably hear. Now be sure to connect the FX to a channel on your receiver that is set to large so that all bass material is being sent to it. Take note of which side you don't here the sound from. Now carefully remove the woofer from the side that you don't hear while still leaving the leads connected to the woofer, and play the same passage at the same level. Now if you can feel the cone vibrating you're in good shape. If not, it's time to contact polk.

If there is anything not clear about the above, please ask before trying it.

Dave

kmartin971 · February 2006

CMY its possible it needs repair. If you just bought the speakers ask for a return.

cmy330go · February 2006

kmartin971 wrote:

CMY its possible it needs repair. If you just bought the speakers ask for a return.

Don't get me wrong....I realize it is possible. But as many times as we have seen this subject (FX or C), and the fact that he didn't hear a difference between the two I think it is highly unlikely.

My last post was not meant to sound harsh. Sorry if it came across that way. I'm just trying to put him at ease.

Also in regards to return/exchange that may be a viable option. I just suggested the above because, if it were me I would rather just pull out a driver to check it rather than box up and haul (or ship) them back to the dealer.

Just $0.02 worth.

LSI/FX Question

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