LSi C shielding

[Steve@3dai]

So I popped in Atlantis last night and was ready for some DTS goodness.

Unfortunately, during scenes will semi-heavy bass in the center channel (set to small) it would distort my TV!!!

I had the LSiC on top of my 34" HD Toshiba, but now I've got it on the floor.

Aren't these things supposed to be monitor friendly? Am I missing something?

Setup:

LSi9
LSiC
Arcam AVR-200
Toshiba 34HF81 TV
Toshiba SD-4700 DVD

- Steven

[Steve@3dai]

Here is how it was setup:

http://www.3dai.com/steve/fullsystemsmall.jpg

[rskarvan]

I'd be seriously P.O. if I were you.

[Steve@3dai]

Yea, it's kinda pissing me off.

[hoosier21]

could it be from the vibrations?
maybe a mouse pad or something to isolate?

[Steve@3dai]

But it distorts the colors, not just makes it move

[rskarvan]

Steve,

Call Polk and pitch a bitch. This is obviously a design flaw
that needs to be immediately addressed. Center speakers
are supposed to be well shielded. My guess is that you have
an extra sensitive TV. Ya know... leaving that speaker on your
TV can screw it up bigger than SHi#. Get that thing off of there
ASAP. Serious.

[Steve@3dai]

Yea, I took it off. I just wonder if I need to get my TV re-aligned now. I'll do some Avia tests tonight and make sure everything is kosher.

Yea, I was under the assumption that I could place a center channel on top of my TV, as that's what they are designed for.

[Kenneth Swauger]

Hello Steve,
I'm sorry you're having a problem with the LSi C speaker. This is the first instance of this kind of problem and I can assure you it is designed to be video shielded. Sometimes the shielding cup may become dislodged from the back of the driver or the reverse polarity magnets may not have been charged properly. Please telephone us at 1-800-377-7655 and I'm sure we can be of help.
Regards, Ken Swauger

[Steve@3dai]

Thanks Ken, I knew I could count on Polk. I'll give you guys a call tomorrow.

- Steven Tellman

[Steve@3dai]

Did the Avia re-calibration tonight, actually for the first time. Everything came out very well, w/o the center channel on there. Got all the color, brightness, tilt, etc all straightened out, looks really good :)

[mantis]

Polk to the rescue again...gotta love this company.........I wonder If I'm on to something?........................................ ........

[Steve@3dai]

Called up customer service today, and I have new drivers and a tweet coming to my house by tomorrow. I'll switch them out and see if it makes a difference.

Polk rocks!

[cookaa]

Just got my LSis yesterday.

Listened to Hell Freezes over DTS DVD.

TV pictured bounced under the low frequency driver (Biwired center) and the picture changed to a greenish color.

Not cool

Steve, let me know how your new stuff works.

[Steve@3dai]

Will do sir.

[hoosier21]

Two of them doing it :(

[l80241]

I'm not sure if it's the same issue, but I had a similar experience. LSIC resting on top of Sony 27" tv. I stuck the little rubber pads that came with the speaker onto the bottom of the speaker to help isolate it.

I was playing around with Avia on the center channel and did the test that sweeps from higher frquencies to lower frequencies. When it started getting into the lower range (do not recall which freq) the TV freaked out, colors changed, the picture wobbled all over and a definite electronic smell wafted over the room.

I just assumed that test was not meant for a non-full-range speaker, but maybe it's a actually problem with the speaker.

Good news, is I have not seen this during normal playback of movies, or music. Then again I have not cranked it too loudly.

[Steve@3dai]

Well, my new drivers should be in today. I'll let you guys know what's up.

You should have the LSiC set to "small" in your reciever anyway.

[rskarvan]

One doing it is a potential shipping damage problem.
Two doing it is almost certainly a design issue - one that
is perhaps easily fixed. Maybe Polk should consider
recalling these LSi Centers... or, maybe Polk can send out
to each customer a "fix-it" kit.

[Steve@3dai]

There has been 3 doing it ;)

["Polk" Paul DiComo]

This phenomenon comes as a big surprise to us as it hasn't happened to us on our TVs here or in our homes nor in review situations. But we believe you (even Steve), really we do.

I want to assure every LSi owner or potential owner that we will do everything in our power to get to the bottom of this and solve it. We WILL solve it. We will kep you posted via this forum on our progress and the ultimate solution to the problem. Stay tuned.

In the meantime, set the center speaker to the Small mode and use the supplied rubber feet or other vibration isolating devices such as Vibrapods. If that doesn't do the trick, move the speaker farther from the TV by raising it up with books or some other handy substance.

DO NOT go out and buy bucking magnets as suggested in one reply. The drivers have bucking magnets on them already and adding more will make the problem worse instead of better.

Ken will stay in touch with anyone who has the LSiC to gather further information that may help us track down the source of the phenomenon. If you have an LSiC and haven't been in direct contact with us, please call or email Ken Swauger (800)377-7655 ext. 891; mailto:kswauger@polkaudio.com.

Be patient We will come up with a solution.

Paul

[Steve@3dai]

Paul is my hero (really!).

I have my Arcam AVR-200 set to have the center as small, but I think the cutoff for this amp is like ~60Hz, I'll do some more testing tonight (whether or not I get the drivers in).

I had the supplied rubber feet on the front of the C to give it a little angle.

- "Journalist" Steven :)

[phuz]

Maybe you knocked something loose in the bi-wiring process?

[Steve@3dai]

See other post in speakers ;)

["Polk" Paul DiComo]

Steve,
Man you're making me blush. Hey you should see the new rims Justin got for his WRX. Cool. I'll have him post a new photo. You'll be jealous. How many speeding tickets so far?

[Steve@3dai]

2 tickets. 85 (or so) in a 65, and 66 in a 45 (dropped to 55). The 66 one was on a road called 2222 here in Austin, MEGA fun to run! Darn motorcycle cops ;)

I need to update my pictures in the gallery as well. New head unit, new wheels, and well, I got a new subwoofer. Don't beat me Paul, but I went with a Image Dynamics IDQ10. It's less forgiving than the Polk, and I had to cross it over at like 55Hz without making it boom. The GNX10 did not boom even at 70Hz crossover. But the IDQ10 hits harder.

[Steve@3dai]

No drivers yet. Should be here today. That will give me the weekend to play around with 'em.

- Steven

[Steve@3dai]

Well, well. Got the drivers in. My previous ones were made in August, and these November. Just FYI.

It DOES NOT fix the problem unfortunately. I trust Polk to address this problem promptly and professionally. I know Paul and Ken will make sure it gets fixed, so don't fret people :)

Ken or Paul, you are welcome to call me at home or work, I will email you my phone numbers.

- Steven

[mantis]

Keep this post alive with your results.I havent seen a shielded speaker do that yeat.Sorry your having problems,but as everone knows Polk will go out of there way to fix it.
So besides your color problems, how does your system sound???

[scottvamp]

You got an extra set of speakers for FREE. That is pretty cool.:D

[Steve@3dai]

I gotta send 'em back :)

[scottvamp]

Bummer!!!!!!!

[mantis]

Just the center right???

[Steve@3dai]

The center what? They sent me three drivers to replace all three drivers.

I get to keep only what I had in the first place.

[mantis]

I thought you where going to send the entire center channel back.Not just the drivers.This is weird what your going threw.

[Steve@3dai]

We're still working on it, just to update people :)

[mantis]

I hope this works out.......I'm looking for Info in here.This might not be a problem for me, but I can't see how they can't shield the drivers.

[Kenneth Swauger]

Folks,
To keep everyone up to date on the progress of the LSI C problem, here's what has happened. We sent replacement tweeter and drivers to Steve who has exchanged them in his speaker and the symptoms remained the same. We then sent four of the Sorbothane isolation discs, that are normally used to separate the satellites from the bass unit in the RT3000p, to both Steve and Dan (the owner of the Sony 27"). I have heard from Dan that the discs eliminated the color shifting and reduced the level of picture jitter, on his Sony, while playing the frequency response sweep section of the Avia disc. His opinion was that while it didn't completely go away he felt the results made it acceptable. Please note that Dan had also commented that he didn't see the original problem during movie or music listening, only during the low frequency section of the test disc. Steve has probably received, or will receive, his Sorbothane discs (I made a mistake in the part identification on the first items I sent, but sent the correct part UPS red, the next day). Hopefully Steve will notice the same level of improvement. The third person who mentioned the same kind of problem should contact me at kswauger@polkaudio.com for similar help.
Here, at Polk, both Paul and I are coordinating research efforts to duplicate and cure the problem. We know the Sorbothane discs are not the final answer, but will help us understand the nature of the problem and offer a reduction in the severity of the difficulty. Anyone who knows Polk Audio's history knows we will do everything necessary to solve the problem.
Regards, Ken Swauger

[hoosier21]

I guessed it was a vibration thing, but why would this speaker be worse than any other center channel speaker?

Can you guys tell us, do you feel the cabinet vibrate when you do the sweep? I would think it would have to vibrate pretty hard to screw up the picture.

[Steve@3dai]

Well, vibration might be part of it, but it's the color shifting that I am worrying about. I should get those discs today (will ship your package tomorrow Ken). I will let you all know what's going on.

As a test, I threw a LSi9 on top of my TV (well, not threw, but you get the idea) and it also did the same thing. Which was pretty expected.

[hoosier21]

Solution is simple get another TV, kidding

what about your last speaker? what was it? was it on top of the TV? Could this be something to do with the TV not liking ANY vibrations? When you say it distorts the color, is it along the top or all over the whole picture?

I am very interested, the LSi might be my next adventure.

[Steve@3dai]

This is my first center channel. So I don't have any other experience.

It's along the top, on the right, which is the bass speaker.

My TV is just fine thank you, 34" HDTV 16x9 is nice :)

[goingganzo]

set the speaker to small? would that work? i have my 400i set to small.

[Steve@3dai]

It is set to small.

I got the pads today, and put them on (kinda sticky, ewww). Didn't make a whole lot of difference in my case.

The best place to see the "noise" is on the Nine Inch Nails concert DVD, track 9 (La Mer). The opening has a wicked bassline that makes my TV dance :)

[mantis]

I've been following this post since the beginning,hoping you would resolve your problem.

I think there is 2 things you can do th get to the bottom of this

1)Get a ISF certified tech out to your house to test if the centerchannel or better put why the center channel is causing you problems.My guess is that it's resting on something inside the Tv causing it.The magnetic field is sheilded in the speaker,and you replaced the drivers with new ones.Polk has been making center channels for a very long time.My guess that it's shielded correctly or other would be chimming in.

2)Move the center channel to the bottom of your Bolts stand.I know its alittle low for center channel placement,but if you raise up the front of the speakers with rubber feet,you can get it 2 sound pretty good.
Or build a center channel shelf over your tv.Others in here have done this with the cs400 as it was 2 big for there tvs.
SOMEONE WHO DID THIS WOULD YOU PLEASE CHIME IN ONHOW YOU BUILT YOUR SHELF???????

OK man I hope you get to the bottom of this.Please keep us all informed with your results.
Dan

[Steve@3dai]

Originally posted by mantis
My guess that it's shielded correctly or other would be chimming in.

I am the 3rd person on this thread to chime in, and we all have different TVs.

- Steven

[DarqueKnight]

Originally posted by mantis
Or build a center channel shelf over your tv.Others in here have done this with the cs400 as it was 2 big for there tvs.
SOMEONE WHO DID THIS WOULD YOU PLEASE CHIME IN ONHOW YOU BUILT YOUR SHELF???????

I used two identical audio equipment racks that were slightly taller than my rear projection TV. I then placed a half inch thick, 6 foot long by 1 foot wide shelf over them.

[goingganzo]

easyest way to buld a shelf is to get angle brachets and a piece of shelving i perfer glass you find 2 or 3 studs atach you brackets to them with 2 1/2 drywall screws you can get dreative brackets or anything you want i usto have a 19 inch glass shelf with a curved end and 2 black brackets the ones you get at home depo that hold 1000 lbs it was sweet till i got my bigscreen and had to take it down now the glass is on some little wine racks for a tabble for the rear seat

[gil]

Steve,
What stands are you using with the LSi9 and where can I find them reasonably priced. Did you look at any other stands besides these?

Also, curious as to how your setup sounds with no center(phantom) vs with the LSiC. Right now I am not using a center and it surprisingly seems to work well, but I do plan to get the matching center.

Also, what are you using to drive the Polks btw.

Thanks,
Gil

[Steve@3dai]

I am using the 18" Sanus Natural Foundations stands. They hold the speakers up quite nice. They run like $100 from Polk.

I still use the center, just have it on the floor. Not optimal, but it works for now.

I am driving them with an Arcam AVR-200.

- Steven

[gil]

Steve,
Sounds good. How would you think the Sanus stands (wood) compare to my heavy metal Sonus faber stands. I need a 2nd pair of stands and don't want to get another Sonus pair.

Also, any opinions of the LSi9 vs the Lsi15, each used with a sub? I am thinking of getting 15's and moving the 9's to the rear. Or I could get FX for rears and a 2nd Hsu subwoofer.

[hoosier21]

Any updates on this problem?

[Steve@3dai]

I don't know of any. Still doing it on mine.

[scottvamp]

Using a fairly large/heavy center speaker sitting directly on top of a crt television (*IMO* are just too small for a powerful audio HT setup anyway) is just a really bad ideal shielded or not. This isn't a puny bose speaker that sits on 20/30" tv's. Give it some space man. Be creative. Mains don't work either? My car has airbags but I am not going to smack into something to see if they work. There shielded within a reasonal small distance? It is sitting directly on your crt. :confused:

[Steve@3dai]

Originally posted by scottvamp
Using a fairly large/heavy center speaker sitting directly on top of a crt television is just a really bad ideal shielded or not.

Hmm, funny, I didn't think so. And my TV is plenty big for my powerful HT, thanks.


Originally posted by scottvamp
This isn't a puny bose speaker that sits on 20/30" tv's. Give it some space man.

Nope, it's a real man's center channel. And it's got a 1/4" between the plastic and the speaker, should be plenty.


Originally posted by scottvamp
My car has airbags but I am not going to smack into something to see if they work.

You should try it, it's quite fun. Lemme borrow your car real quick.

Obviously Polk looks at this as a problem, since they've spent some time working with me to find solutions. Thanks for adding to the solution. :rolleyes:

[Kenneth Swauger]

Forum readers,
We believe we have discovered the cause of the television interference, on the LSiC, it is coming from one of the inductors on the speaker's internal crossover. There is a rather large inductor in series with one of the drivers that, as a signal flows, produces a magnetic field which varies with the frequency and strength of the signal. The stronger the signal passing through this inductor the wider the magnetic field which in turn begins effecting the television's picture. Our magnetic shielding has concentrated on the tweeters and drivers and during static magnetic field testing there is complete compliance. However, under certain crossover designs and playing conditions the crossover becomes a source, as well.
Now that we know the cause we have to develop a cure, perhaps using two inductors arranged to cancel the magnetic fields, or a shielded mechanism for the coil itself. But, what ever it requires we will make available to any LSiC owner at no charge. Also, keep in mind that this is only evident under higher playing volumes and not every television set will react to the same degree. I will certainly make everyone aware of the progress of this matter and encourage everyone to contact me directly if there are any concerns. We also appreciate everyone's patience and willingness to work with us.
Regards, Ken Swauger

[rskarvan]

Good Job Ken !
Using this forum, you were (or, will be) succussful in solving an engineering issue that was missed in internal product development and test. Time to update those internal FMEA's.

By finding this problem early in production, Polk can save face with the vast majority of customers - thus, reducing problems associated with warranty, etc.

I prefer the reliability of an old airplane with a zillian flight miles, vs. a brand new one straight from the factory.
I prefer to buy new model car the year AFTER they have been introduced - after a few engineering bugs get worked out.
Lastly, I prefer to buy old SDA speakers vs. newer Polks.
(Just had to get that in there).

[Steve@3dai]

Polk comes through, once again.

I am a sucker for the latest and greatest. My WRX was only 6 months old in the US when I got it, and the LSis were fresh off the blueprint :)

[Kenneth Swauger]

Forum members,
Thank you for your supportive comments, believe me they are appreciated. Perhaps I can use this situation to describe how problems, such as this, are handled, at Polk. We have a Corrective Action Board (CAB) that meets every two weeks and has a representative group of people from all of the major departments, Customer Service, Engineering, Purchasing, Quality Assurance and Management. Anyone can introduce an issue concerning any problem that requires attention, from "catch cups" (the little rubber cups that hold the grille cover pegs in place) to issues as serious as the LSiC. As a participating member of the CAB I brought this problem to the board's attention. In turn, the head of the committee, Mike Carney, assigned someone in the engineering department the task of finding out everything possible about the nature of the problem. In today's meeting an engineer gave a report explaining the experimentation that he did to diagnose the problem. We responded with questions and recommended changes to the testing procedure of all future designs and began determining the best way to cure the problem. As soon as the meeting was over and I felt there was important information, I addressed the Forum. I hope this is an interesting insight as to how we operate.
Regards, Ken Swauger

[scottvamp]

Should'nt this have been noticed before distrubution of the product? I think many people would agree with my above point. I need a picture of a CS1000 sitting directly on top of a 13" tv. Come on visualize it. Probably havent put this exact "process" into factory testing yet. Anyway glad to see Polk satisfying customers yet again. Great job guys!!!!!!!:)

[DarqueKnight]

Originally posted by rskarvan

Lastly, I prefer to buy old SDA speakers vs. newer Polks.


Me too. However, the new LSi series is a step in the right direction.:D

["Polk" Paul DiComo]

OK folks here is some good news and bad (well not that bad).

:) We determined that Steve is hallucinating (again) and that the problem is all the result of some whacky weed
:) Only kidding. Seriously folks, we did duplicate the problem on some TV sets
:) We did manage to figure out why it is happening
:) It is NOT a shielding issue with either the drivers or the tweeter
:) The LPF inductor in the crossover is radiating magnetic energy when high current goes through it
:( The bad news is that we don't have a practical solution figured out quite yet. It's not exactly trivial to relocate a crossover component or come up with an alternative.
:) The good news is that we WILL figure it out and come up with a fix.
:( Steve, you get to be a ginuea pig
:( Steve, stop playing your Brittany Spears concert DVDs so loud

[mantis]

Brittany Spears Video?????who needs sound.......

[F1nut]

I like to hear her say the F word!

[nascarmann]

I would like to watch her do the F word.....:D

[F1nut]

No, like when she says F me F1nut.......I'm dreaming, man am I dreaming.

[nascarmann]

I see said the blind man......

[Steve@3dai]

I'm down with being the ginuea pig.

Britney Spears huh? Naw, my heart is set on Christina!

(Stay on topic... stay on topic ;))

[mantis]

But Sir I can't hold it any longer!!!!!

[daddy8]

I have a sony and my SRS's did a number on my 35" set. Then I got the boss (my wife) to let me get the Polk Audio surround system I am using (rt800i, cs400i, fx500i and psw350) driven by a harmon kardon avr7000. DTS is awsome. Got to think highly of Polk Audio. They understand customer service and stand by thier products. It also does not hurt that they sound great as well. We can all hope that Polk Audio is around for years to come.:D

[pvabeach]

I too am having a problem. When playing at loud levels, ~95db, the picture on my Sony XBR 36 wega actually bounces downwards with transients!!!. This did not occur with my CS400.
Otherwize, the sound of 5 speaker LSI setup is AMAZING!!
I've gotten up too many times to answer phone or door or check to see if its raining outside, only to discover it was coming from the speakers!.

[pvabeach]

PS, my center is on a shelf about 3 inches above TV. Paul

["Polk" Paul DiComo]

Get in touch with Ken Swauger (800)377-7655 ext. 891 or email polkcs@polkaudio.com. Ken will let you know when the modification is available. The problem lies in the crossover - an inductor is radiating a magnetic field. Last I heard we were going to order a different type of inductor and see if that solves the problem. I'm not sure what the current status is. Ken can give you an update as he is actively involved in the project.

[Kenneth Swauger]

Hello,
The engineering department believes they have a modified crossover for the LSiC speaker that will eliminate the interference problem with television sets. I would like to send one of these crossover networks to anyone who has this problem and determine if the change is successful. It would involve some simple tweeter/drivers removal and installation of the new crossover from the back of the enclosure. Please contact me at kswauger@polkaudio.com or telephone me at 1-800-377-7655 extension 891 to get receiving address and more detailed instructions.
Regards, Ken Swauger

[Rotarydude]

I also have the same problem using the LSiC in reference volume. At lower volume it's okay.

I currently is waiting for my reseller to replace my first one, because it had some damage to the wood work.

If the second exhibit the problem again, what is the procedure on getting a LSiC that will not have this problem at high volume?

["Polk" Paul DiComo]

See Ken's message right above your post. That explains in detail what to do.

Happy New Year.

[howie777]

As an engineer, I am pretty impressed that polk acutally reads there message board! Its hard to find good companies, Marantz only gives a mailing address on their website! Who asks questions via mail? And the fact they will actually SEND you things to try out is AMAZING! Well even though I can't find a close place to listen to the LSi speakers I'm going to buy the LSi9s and LSiFX and wait until the center is fixed. Sounds like all the speakers might need this fix in the future (updated modles that is, just to be a bit better) Oh and my RT10s I bought for $500 5 years ago blow away the $1400 B&Ws I listen to as possible replacements today. LOL keep up the great work Polk. And that is pretty interesting the inductors where the problem. Man I love electronics. How does an aspiring engineer make his way into the audio world? I have 2.5 years under my belt, 1.5 on DVD players for the auto world :-( Working for auto company X as a supplier is a pain. To see a product with such potential be butchered by someone who has no clue is so painful! Note, I used company X to protect the guilty and my JOB!

Great job Polk!

Howie

[infinitiqx4]

Any updates? When will new LSiC begin shipping without the problem?

["Polk" Paul DiComo]

OK, Here's what's happend with this shielding issue:
We have come up with a solution that involves installing a modified crossover. Anyone experiencing the problem should contact customer service at 800-377-7655 to get a new crossover. Keep in mind that this phenomenon only happens with a few sensitive TV sets. To date fewer than 1% (.6% to be exact) of the installed LSiCs have required the modification. We estimate that modified units will start getting built sometime this summer (it takes a long time to modify drawings, order new parts etc. etc.).

[Zen Dragon]

To all at Polk. Yes this was a fascinating look into the processes at Polk. It is not easy to foresee every possible situation a product may be used in.
Great Info !!
Great Response !!
Great Work !!

There are presently 9 speakers in my little Polk family and it's nice to know they not only sound great, but are supported so well by the Mfr.

Mega Kudos


:) :) :) :)

[lsi15]

It is great to read all this info.

I have a questions for folks at POLK, will the LSIC cause problem to the SONY pk-57WV700?. I am getting TV deliver in 2 days.

Thanks,

My current system is: LSI15, LSIC, and LSI9.

["Polk" Paul DiComo]

Gee, I really don't know. We don't have the ability to test every TV set. I think that set is a 57" rear projection set although the Sony web site does not show that model (my personal vote for most useless CE web site goes to....drum roll.....SONY!). If I'm right, then the answer is you have nothing to worry about. The guts (guns) of rear screen projector sets are way down near the bottom of the cabinet so that type of TV is virtually impervious to magnetic interference from any speaker place atop it.

[scottvamp]

If I'm right, then the answer is you have nothing to worry about. The guts (guns) of rear screen projector sets are way down near the bottom of the cabinet so that type of TV is virtually impervious to magnetic interference from any speaker place atop it.
Paul is right - there are rarely issues with projection tv's. The small crt type tv's where as people are placing the speaker directly on top of the set. I am sure this happens with more than just Polk speakers. 100% magnetic isolation may be difficult. Even if one were to simply place the speaker on "shelf" a couple inches below or above the tv - this would not be an issue. IMO

[lsi15]

Thanks for the response, my mistake, it is KP-57WV700. Anyway, I went out to M A and look at the top of this projection model and there is no room to place the center speaker on top. So it is a none issue. However, you are right Paul, Sony website really suck. One more questions but not related to this issue. All of Polk LSI speakers are 4 ohms, does that means that I have to find a Receiver that support 4 ohms as well? Thanks.

[brettw22]

Originally posted by lsi15
All of Polk LSI speakers are 4 ohms, does that means that I have to find a Receiver that support 4 ohms as well? Thanks.

Without a doubt, YES!!!!!

["Polk" Paul DiComo]

Oh it is one of those shallow top jobs. Sanus makes a shelf unit that allows you to put a big center on top of a shallow-top TV http://www.sanus.com/cgi-bin/web_store.cgi

Yes, you should get a rcvr that can drive 4 Ohm loads. Rejoice! The rcvrs that can drive 4 Ohm loads sound better than the wimpy, girly rcvrs that can't. You should consider upper end Denon, Onkyo & Yamaha from the big-brand boys. Also Pioneer's top-of-line units have been getting rave reviews. From the lesser known and tweaky crowd, consider Rotel, Arcam, NAD & B&K. I'm sure the other LSi owners on the forum will chime in with their rcvr preferences.

Here's some basic advice about rcvr choice and power:

http://www.polkaudio.com/home/faqad/advice.php?article=electronics

http://www.polkaudio.com/home/faqad/advice.php?article=pwrratings

[Dr. Spec]

This has been a fabulous thread. Kudos to Polk Audio for their OUTSTANDING CS and R&D on this problem.

CS is one of the reasons I bought Polk and SVS. And the primary reason I'm staying with both.

FWIW, I suspected this was a coil related problem because it cropped up during bass passages. If the magnetic structure on the speaks was improperly shielded, the problem would occur all the time.

When it is intermittent, it is obviously signal related. Any coil's magnetic field strength will increase as the amount of current being passed through it increases. And yes, I suspect setting the center to large and feeding it a full range signal will exacerbate the problem. I wonder if Steve could confirm this if possible.

[scottvamp]

Anyway, I went out to M A and look at the top of this projection model and there is no room to place the center speaker on top.
I'm lost on this one. A projection TV without a "top". No room??:confused: I got's to see this.

[mantis]

The Samsung has like a 3 inch top,no room for a center channel there unless you use some kind of modified centerchannel stand.
The Mitsubisihi DLP is like this, the Sony Grand Wega is also.

[scottvamp]

Thanks Mantis - I get it. Small front shelf. Slopes in the back like a big crt. I hate those. U can always use the space on top of the "other" ones.

[mantis]

The DLP tv's are worse.You should look next time your out and about.Shocking .........HT is really big.Need to put a center channel somewhere.Thin is also in though.

[praedet]

Suck, I have this problem but it is my fault as the x-over is upgraded :(

[McLoki]

any shielding you can put under the bass driver crossover??

[praedet]

^^^That is what I am going to look into. What sort of materials work well for magnetic shielding?

[fuhugtwi]

I accept: In the meantime, set the center speaker to the Small mode and use the supplied rubber feet or other vibration isolating devices such as Vibrapods. If that doesn't do the trick, move the speaker farther from the TV by raising it up with books or some other handy substance.
DO NOT go out and buy bucking magnets as suggested in one reply. The drivers have bucking magnets on them already and adding more will make the problem worse instead of better.

[phuz]

^^^ Hey douchebag, you've been reported. ^^^ Door is closing in 3.... 2...

[Face]

I think it's funny that the spammer knew that the drivers already had bucking magnets.

[D.Invax]

I just started playing with my LSI Megaraid i4 card today
So Im no guru
I hooked 3 drives on it Samsung 400GB in raid 5
got a logical volume of about 799 GB, spot on for raid 5

dont have naslite2 yet
got my CF card, 4x400 Gb drives, just waiting on my CF to IDE adapter