HELP - CS400i Sounds Distorted ??

BESKI64 · July 2002

Please Help, does this problem sound familiar to anybody - and how can I fix it????

I recently (December-2001) upgraded my center from the CS245i to the CS400i with the CC trade up program after reading all of the comments on this site.

When I play the usual DVD demos (Gladiator, PM, Toy Story2 etc.) the center channel speaker sounds great for "Special Effects" and detail and it blends well with my other Polk Speakers (See Below).

The problem I notice is more in the "Dialogue" of movies or the "Vocals" of a concert DVD. During certain parts of a movie, I hear a slightly "distorted sound" as if the speaker can't produce the sound accurately. (More on High Notes then Low Notes.) The last time I heard this type of sound was with my $250 All-In-One K-Mart stereo in college when we tried to jack up the music, but I don't think I should hear it with the Polks!!

The best examples of this "distortion" happens when the character screams or yells (EXAMPLES: Tom Cruise yells several times in "Vanilla Sky" and Nicole Kidman Screams in "The Others"....and at times Don Henley's Voice in "Hell Freezes Over" and "Inside Job Tour")

I have calibrated my system several times using Avia and SPL and have made some minor receiver adjustments to the Center's Volume / Bass / Treble with no noticeable change.

Please let me know if there is a way to test my Center Speaker and the Drivers and/or Tweeter to determine if there is a problem with the speaker itself or if this is how it should sound.

Thanks,
Tom (Beski)

Mains: RT800i + RT35i
Center: CS400i
Rear: F/X500i
Sub: SVS 25-31 PCi
Receiver: Sony STR DE945

jcaut · July 2002

You have a very nice speaker set-up, and the CS400i should blend in perfectly. I've never noticed the "distortion" that you describe, but it definitely should not be happening. Try hooking up the CS400 as one of your fronts and playing some music or dialogue through it. If it sounds alright then, the problem is probably not with the speaker.

I notice you're using a DE-series Sony receiver. Sony receivers have been discussed at length on here, and most people don't have a very favorable opinion of them. I don't say that to knock your system, but the amps for the center and rear channels are often less robust than those for the front channels. It's possible that during loud center-channel passages your Sony is running out of juice.

If you think that it's a speaker problem, contact Polk customer service and they'll help you out.

Jason

P.S. You might also check your speaker levels and settings. Those Sony's have a myriad of tone-control options. I'd try setting those all to 0db or flat, as well. I've got my CS400i set to "small" and I'd recommend that as well. The speaker should handle "large" but it's an easier load for your receiver if you set it to "small".

elsid88 · July 2002

I will bet that the Sony is not supplying enough power to your center speaker.

Do you by chance here any distortion in your surrounds?

Try this:

If you can, look at your Sony manual and see how many Amps the reciever has. Multiply that by 120. This should give you the total Watts that the receiver can produce. Then subtract 100 to 150 Watts for all the electronics. Take that total * 75% to 85% which is the usual efficiency of most mid recievers and take that number and divide by 5. This should give you the true Watts per channel.

Ex:

I have the Denon AVR4800. It puts out 10.9 Amps.

10.9 X 120 = 1308 Watts - 150 Watts for electronics = 1158 W.

1158 W * .75 = 868.5 / 5 = 173.7X5.

In actuality the Denon has a rating of 125X5, yet has been tested up to 148X5, which means the Denon might draw more power than 150 Watts or it might be a little less efficient or the combination of both. However, it does show that there is enough power being produced to push 125X5.

Check your numbers and see what you come up with.

For a more detailed thread check this out.

http://www.hometheaterspot.com/htsthreads/showflat.php?Cat=&Board=UBB5&Number=26370&page=4&view=collapsed&sb=5&o=&fpart=1

Good luck...

Tom...

schumach · July 2002

beski64,

Is your center speaker set to large or small on the receiver? On the AVIA DVD do you get the distortion when doing the 150-HP test?

begbie · July 2002

Sounds like you blew the tweeter. Reminds me of a similar situation at the a/v store I use to work at. We decided to take the cs400i out of the speaker room and on to the main showroom.
When tested, everything sounded muffled when put to the test. Someone had apparently overdriven it.

begbie · July 2002

Beski, you indicated that you "recently" upgraded in DECEMBER/2001 . Was there any distortion back then? Or did it all happen just now?
Just wondering so we can clarify if something is defective or a setup problem.

goingganzo · July 2002

when i had my sub set to high it would mahe my center sound quiet i would have the turn it up turn it down when i watched a movie

HELP - CS400i Sounds Distorted ??

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