lsi25 subwoofer problem

duranfan82

Alright bare with me as i try to explain this. my main home theater consists of 4 lsi25's, lsic center, 2 fxi3's and a velodyne spl12. I have a sony 5200es receiver, sony es dvd player, ps3, wii and a pioneer 5020 plasma. My lsi25s are plugged in to a monster power reference powercenter hts 2600 3 of them are plugged in with extension cords and those 3 have virtually no bass and the one that is plugged directly into the powercenter has great bass. the extension cords are from home depot maybe that is the problem. Hopefully somebody can help me with this problem.
Thanks Trevor

McLoki

What guage is your extension cord? The thin brown home use ones, or the more heavy duty indoor-outdoor ones? (should not matter, but it would not be the oddest thing I have ever seen in this hobby)

Could be placement of the speaker in the room,
Could be how they are set in the AVR, (large or small and crossover point selected)
Could be volume set on the back of the plate amp (of the LSi25)
Could be crossover point set on the back of the plate amp (of the LSi25)

One quick way to narrow it all down is to swap one of the speakers with no bass for the one that has it. With no changes to the speaker other than location and where it is plugged in (and what channel it is plugged into) is the bass better or no?

report back and let us know.

BTW - Welcome to Club Polk.

Michael

nooshinjohn

First thing that pops to mind here is that the LSi's love power and being a 4ohm load, are next to impossible to run effectively from a receiver. If you are running 4 LSi-25's and an LSi/C, I would be willing to bet that one of the biggest problems you have is that they are being underpowered. I suggest investing a bit in some external amps that are stable with a four ohm load and this will go a long way towards correcting the problem.

Power specs for the Receiver...
Output power: Two-channels (20 Hz- 20 kHz, 8 ohms, 0.09% THD; 4 ohms, 0.15% THD): 120-Watts per channel 7.1-channels (4 or 8 ohms, 1kHz, 0.7% THD)
Front: 130W + 130W
Center: 130W
Surrounds: 130W + 130W
Surround Back: 130W + 130W

McLoki

nooshinjohn wrote: »

First thing that pops to mind here is that the LSi's love power and being a 4ohm load, are next to impossible to run effectively from a receiver. If you are running 4 LSi-25's and an LSi/C, I would be willing to bet that one of the biggest problems you have is that they are being underpowered. I suggest investing a bit in some external amps that are stable with a four ohm load and this will go a long way towards correcting the problem.

That was the first thing that came to mind for me as well, but the woofer is run from a plate amp and if he is not getting any bass, it should be a room or signal issue of some sort.

I do agree, that an external amp would help - but in this case, I do not think it will solve his problem.

Michael

nooshinjohn

There is no doubt in my mind that the performance of his system will improve with the addition of a couple dedicated two channel amps to run the LSi's... So that I understand, each LSi-25 has it's own internal plate amp, essentially a powered sub in each cabinet. The op is therefore trying to run 5 subwoofers in his setup. Any possibility that they are cancelling each other out?

duranfan82

sorry I was gone for so long. everything is turned on, i tried switching them around and whatever one is plugged directly in the powercenter works great. not using the lfe but im using the speaker level input.the speaker connectors are on. The speakers are set to large on the receiver. You can hear just a little bit of bass coming out of the 3 that are not working right. I appreciate everybody's feedback. Trevor

duranfan82

I went through the receiver settings and notice the speakers were set at 8 ohms so i switched them to 4 ohms and the fronts sound great now. Hopefully that fixes everything and I appreciate everybody's help on this. Thanks Trevor