Started with Logitech z680 -> Upgraded Speakers. Getting pop when first powered on.

conceyted

Hi,

I have just begun to upgrade my HT setup. For years now I have been using Logitech z680's that were originally hooked up to my computer as the 5.1 surround sound for my front room. I recently began upgrading the setup but have yet to purchase a subwoofer and receiver. I put some new speakers on my setup today. Ended up with the Polk RM20 5 speaker setup. I am still using the Logitech z680 subwoofer/pre-amp unit to power the new speakers.

A few questions. The Logitech z680 amp claims:

* Left/Right: 62 watts RMS x 2 (into 8 ohms, @ 1khz, @ 10% THD)
* Center: 69 watts RMS (into 8 ohms, @ 1kHz, @ 10% THD)
* Rear Left & Right: 62 watts RMS x 2 (into 8 ohms, @ 1kHz, @ 10% THD)

Will my new Polk RM20 speakers be safe powered by the Logitech amp until I buy a receiver? Also, when I turn the Logitech system on, the polk speakers let out a short but slightly loud pop at power on. Once powered on, they sound fine and no longer pop. Is this harming my speakers? Are there any things to be concerned with? I get a slight hiss out of all of my speakers when sound is not coming out, but this was also present on the Logitech satellites and probably isn't much to be concerned of.

Future plans are to invest in a Denon AV-790 and either a Polk PSW111 or a DSWPro 400.

Thank you,

Chris M.

conceyted

Anyone?

nguyendot

It can harm your speakers yes. That THD% can harm your tweeters as it will send a ton of dirty power to them. 10% is an insane rating by normal standards. We usually want 1% or less and that already is pushing it.

AsSiMiLaTeD

I actually would not worry about that ten percent figure on the thd, as that's only going to be at the full rated power of 62 watts.

Just don't push those speakers very loud and you should be okay.

As an fyi, thd isn't what usually kills your speakers, as it is harmonic distortion. Its the other type of distortion you gotta watch out for.t

conceyted

I read about THD and most seemed to suggest that it wouldn't harm your speakers to run a high THD to them. Glad to hear I should b alright for now. As soon as the 790 gets back in stock over at us appliance I plan on buying one.

Thanks guys!

SivaNevets

u should consider 590 too, to me theres no real difference between the two.

conceyted

The 590 was definitely a consideration, but I purchased and installed some in ceiling rear satellites and I plan on buying a receiver with 7.1 capabilities to use my RM20 5 pack at the fronts and low rears and allow the ceiling speakers to be the high rears. It could turn out to all be a bad idea and I could end up spending 100 dollars more than I need to, but I kinda feel like I should give it a shot.

conceyted

Looks like I won't be waiting too long and risking damaging anything after all. Last night, on a whim, I called up Electronics-Expo.com to see if they would work with me on the pricing of a Denon Avr-1910. They had run a special a few days ago for about 12 hours that gave 30% discount on Denon receivers. The customer service rep I spoke with really worked hard to get me a price I was comfortable with, and while I did spend a tiny bit more than the 30% off coupon they had a few days ago, I really got a great great deal and I can't complain.

They are out of stock on the website, but the CSR yesterday mentioned they have some at their stores and that it should just take a day or two to get one from their stores and ship it out to me. I couldn't be more thrilled. Now all that is left is finding a decent subwoofer to complete my new setup.