Underpowering speakers?

[Slec]

An earlier thread led me to the decision to purchase new Fronts and Center for my Home Theater. I've done a ton of work with car stereos but I don't want that to cause a bad decision.

I have an Onkyo 605 (90 watts RMS)
I'm looking at buying either Klipsch F3's or Polk RTi10's. The Klipsch's are rated at 150 watts rms but have a high sensitivity (98db). The Polks handle up to 200 watts rms, but at 89 db. Significantly underpowering speakers can lead to distortion which will blow the horns. Should I be worried about that with the above speaker sets?

Thanks, and opinions are also welcome on the speaker choices

[Kratos3]

I wouldn't worry about it. If you were putting 10 watts into them and cranking 'em up all the time, then I would worry. 90 watts will be great for either of those. I have a preference for Klipsch, they are much more efficient so you don't need a whole lot of power to drive them. I wouldn't worry about either of them being underpowered by your receiver, though.

Hope this helps. get the F3's

[Blu-Dog]

Originally Posted by Slec

An earlier thread led me to the decision to purchase new Fronts and Center for my Home Theater. I've done a ton of work with car stereos but I don't want that to make me make a bad decision.

I have an Onkyo 605 (90 watts RMS)
I'm looking at buying either Klipsch F3's or Polk RTi10's. The Klipsch's are rated at 150 watts rms but have a high sensitivity (98db). The Polks handle up to 200 watts rms, but at 98 db. Significantly underpowering speakers can lead to distortion which will blow the horns. Should I be worried about that with the above speaker sets?

Thanks, and opinions are also welcome on the speaker choices

The Onkyo can handle either set. It's a bit different with 8 ohm speakers, than the 4 ohm standard you see in car stereo, or higher end home speakers that are running at 4 ohm.

If you were looking at the higher end stuff (I presume you're looking at Best Buy for speakers - don't know if anybody else is carrying the F-3's at a storefront) slide over to Magnolia and see what's up with Vienna Acoustics, Monitor Audio, and some of the other high end brands. Most are 4 ohm - Definitive Technologies are the only brand running 8 ohms as a standard. You're very right - not having enough power will cause distortion in sound, and problems with the amp.

Either set, the Polk RT10 or the Klipsch, will sound nice being pumped by the Onkyo. The think is, the Polks won't come alive until you really crank them. The Klipsch will sound better at lower volume - appreciably better, to my ears - but it depends on how you listen to them, or watch films.

Some folks think Klipsch is overly bright at high volume, but their complaints are usually with the higher end speakers. Give them a listen at volume, and have the guy feed them with a modest amp on the rack, not one of the powerhouses they use to impress folks. Anything pushing 80-100 watts is a fair test.

Side note: Power ratings for both the amps, and the speaker capacity, are not all that reliable. When you do your sound checks, take a look at the volume knob when you're hearing what you want to hear - if it's anywhere above 6 on a 10 scale, you're not in a good place to be.

[Slec]

Thanks for the responses. I know with Car stereos I would rarely connect an amp to a speaker that was only 60% of its rms level, unless they were extremely efficient. Didn't want to assume anything about Home Theaters as a result.

Yea I was checking them out at Best Buy. What really grabbed my attention was the Klipsch Center Channel. With all the people in the room I couldn't crank it to hear the floor monitors too well. The Vienna Acoustic sounded even better, but if memory serves it was about a grand, which I can't afford for just a center channel.

In terms of usage, I'm probably 35% movies (loud), 35% tv (not loud), 15% music (very loud), 15% games (not loud).

[Blu-Dog]

Originally Posted by Slec

Thanks for the responses. I know with Car stereos I would rarely connect an amp to a speaker that was only 60% of its rms level, unless they were extremely efficient. Didn't want to assume anything about Home Theaters as a result.

Most speaker manufacturers - either at the component level, or with fully assembled speakers - don't give the nominal power ratings. Too many variables, I guess - they don't want to be on the hook to verify an amp maker's true output. They just stick with db ratings, tell you where they expect the speakers to overload, and that's it.

It is something you have to approach carefully in home theater, too much money involved to get it wrong.

Originally Posted by Slec

Yea I was checking them out at Best Buy. What really grabbed my attention was the Klipsch Center Channel. With all the people in the room I couldn't crank it to hear the floor monitors too well. The Vienna Acoustic sounded even better, but if memory serves it was about a grand, which I can't afford for just a center channel.

Klipsch gives you the best bang for your buck. You get the best sound out of Polk with the Rt12 series, and now you're spending a lot of money, and need a beefier amp - not worth it unless you're filling a huge space. My son got the RF-62 series, and I am quite impressed with the result. He's running them with a Pioneer amp, can't remember which model, 100 watts per channel, and it's very, very nice.

In terms of usage, I'm probably 35% movies (loud), 35% tv (not loud), 15% music (very loud), 15% games (not loud).[/QUOTE]

That does it - Klipsch will work. It's the TV and games piece. They have a great tweeter, which will support voices at low volumes - you won't miss dialogue, even if you're using a basic sound mode instead of DD or DTS. But give them a listen. If you get to the sound room when the store first opens, you can usually have the place to yourself for a while. Later in the day, it's a mess of people.

[Footloose301]

Originally Posted by Slec

Thanks for the responses. I know with Car stereos I would rarely connect an amp to a speaker that was only 60% of its rms level, unless they were extremely efficient. Didn't want to assume anything about Home Theaters as a result.

Yea I was checking them out at Best Buy. What really grabbed my attention was the Klipsch Center Channel. With all the people in the room I couldn't crank it to hear the floor monitors too well. The Vienna Acoustic sounded even better, but if memory serves it was about a grand, which I can't afford for just a center channel.

In terms of usage, I'm probably 35% movies (loud), 35% tv (not loud), 15% music (very loud), 15% games (not loud).

You should be fine with those speakers. You just have to listen carefully for distortion.

Underpowering a speaker actually causes the voice coils to heat up and then seize when distortion occurs.

Changing the impedance of a receiver is dangerous too, just make sure they're 8ohms. A lower ohm rating means less resistance, thus causing the amp to push out more power than it rightfully should, causing excessive heat and/or detonation of the amp.

[richteer]

Originally Posted by Slec

An earlier thread led me to the decision to purchase new Fronts and Center for my Home Theater. I've done a ton of work with car stereos but I don't want that to cause a bad decision.

I have an Onkyo 605 (90 watts RMS)
I'm looking at buying either Klipsch F3's or Polk RTi10's. The Klipsch's are rated at 150 watts rms but have a high sensitivity (98db). The Polks handle up to 200 watts rms, but at 89 db. Significantly underpowering speakers can lead to distortion which will blow the horns. Should I be worried about that with the above speaker sets?

Underpowering speakers doesn't lead directly to distortion per se. What happens with lower powered amps is that you're tempted to turn them up more to get a decent amount of volume. Once an amp gets near its rated power, it starts to clip. Clipping creates lots of high frequency energy--much more than in normal music--and hence, puts a lot of stress on tweeters. This stress can lead to burned out voice coils, ergo, dead speakers.

By using a much more powerful amp, you are not as likely to approach the clipping point when you crank up the volume, so the signal being fed to your speakers will be cleaner, and hence less likely to burn out your drivers (up to a point of course!).

[jomari]

your klipsch should be just fine.

[Footloose301]

Originally Posted by richteer

By using a much more powerful amp, you are not as likely to approach the clipping point when you crank up the volume, so the signal being fed to your speakers will be cleaner, and hence less likely to burn out your drivers (up to a point of course!).

You've got to remember that even if you have a 50watt RMS amp and 30watt RMS speaker, you can ruin that too. Just having a larger amp does not solve the problem. It heats up the voice coils if distortion occurs, and it has nothing to do with the amp at the point, you're just going beyond the capabilities of that speaker.

So, you see that you actually want to match a speaker's wattage rating with the amp as close as possible or atleast make sure that you listen for any distortion when it occurs.

[RBFC]

In my opinion, richteer is correct. I've heard about many more tweeters being blown by clipping amplifiers than by melting voice coils. (I've been heavily into audio for over 30 years) The amount of high-frequency "hash" that is produced by a clipping amplifier is startling when you see the oscilloscope trace of that event. This high frequency energy can far exceed the wattage that the tweeter would ever see on VERY loud music.

Lee

Equipment:

B&W 801D (L,R)
B&W HTM-1D (C)
B&W CWM8180 (surrounds, 3 for 6.1)
Krell Evolution 403 amplifier (L,C,R)
Denon AVR4806 (preamp/processor, surround amplifier)
Denon 3930CI DVD, SACD, DVD-A
Samsung BD-P1000
Pioneer PRO1540-HD 60" plasma

[richteer]

Originally Posted by Footloose301

You've got to remember that even if you have a 50watt RMS amp and 30watt RMS speaker, you can ruin that too. Just having a larger amp does not solve the problem. It heats up the voice coils if distortion occurs, and it has nothing to do with the amp at the point, you're just going beyond the capabilities of that speaker.

Right, which is why I said "up to a point". I'd personally have no qualms with hooking up an 50W amp to a pair of 30W speakers. A 500W amp would need more care though, because although it would be very unlikely to kill tweeters due to clipping, it'd probably melt the voice coils if the volume is cranked up too much for a sustained period of time. But it could still be done if one is careful (though I would think that someone who could afford a 500W amp would be able to afford speakers with better power handling than 30W!).

[Slec]

Originally Posted by Blu-Dog

Either set, the Polk RT10 or the Klipsch, will sound nice being pumped by the Onkyo. The think is, the Polks won't come alive until you really crank them. The Klipsch will sound better at lower volume - appreciably better, to my ears - but it depends on how you listen to them, or watch films.

Some folks think Klipsch is overly bright at high volume, but their complaints are usually with the higher end speakers. Give them a listen at volume, and have the guy feed them with a modest amp on the rack, not one of the powerhouses they use to impress folks. Anything pushing 80-100 watts is a fair test.

Thanks so much for the advice. I took my wife over to BB this afternoon to check out the Klipsch's. I gave a listen to the RF-62's and 82's. The 82's were really harsh at loud volumes but appreciably more clear than my current onkyo setup. I liked the way the 62 sounded.

I listened to the Def Tech 7004's and was blown away. They really filled the room with sound when listening to a CD I'd brought along. I couldn't have been more impressed. They are expensive, but wow, what an improvement over even the Klipsch's. Anyone know what to look out for if I saved up a while longer and got these instead?

The more and more one looks into this, the more and more one looks to spend... crazy...

[wakeboredb]

I would be wary of going to Best Buy and judging a speakers sound in the store. Room acoustics are grossly ignored when deciding on speakers. Listening in an open area like a best buy, and then taking them to a much more enclosed room at your house with furniture, hardwood/carpet, windows, drapes, etc. will give you an entirely different sound. Different frequency's will be subject to null's and propogations in your room that are entirely different than the store.

The only truly fair way to purchase a speaker is to either buy it and try it out in your home and return it, or go to a local dealer (which generally has a much greater appreciation for room acoustics) that will let you demo their speakers for a certain time period in your home.

[Slec]

Actually, the guy at Best Buy mentioned many of those things, not all, but most . It was around 1 pm and the store was empty so we closed the doors, moved the speakers that were around them away and he even showed me how placement/distance of the speakers near the wall will affect the way the music sounds. I'll give the sales guy credit, he knew up front I wasn't buying today and still spent 30-45 minutes talking us through a couple different lines and what to look out for.
One of the other guys kept wanting to hook the speakers up to the best receiver in the store. I wanted to choke him, but the sales guy mentioned above understood immediately why I wanted a particular receiver hooked up to the speakers. Sounds petty, but it's frustrating when people don't listen to you when your trying to see what something sounds like when hooked up to something similar to your own setup.

[wakeboredb]

Good luck on your speaker hunt! A couple other unsolicited points of advice I have are:

1. Don't ever let the salesperson give you their opinion on the sound of a speaker. If they say a speaker sounds "harsh", "boomy", etc., you will instantly notice those traits when you probably wouldn't have otherwise. It matters what you hear, not them, so don't let them ruin what may be a perfectly good speaker for you.

2. Take your wife/girlfriend/significant other that is a female and will be using the speakers as well. Females hearing lasts longer than males and is typically more tuned to a broader range of frequencies. A speaker that sounds good to you may not sound good at all to her, and it's important that you both like it.

3. Only demo speakers with your own cd's that you know the songs and how they should sound like the back of your hand. You will be much better equipped to judge a speaker when listening to music that you are very familiar with.

4. Finally, before you get too far into demoing speakers, go to a local dealer that carries top of the line, high end brands. Speakers that cost $1,000's - $10,000's a pair and listen to these. This will give you a good baseline for judging speakers that are in your price range. I recommend some of the high end B & W's, Paradigm, and even Klipsch reference for this.

Enjoy!!!

[Big Daddy]

Originally Posted by Slec

Thanks so much for the advice. I took my wife over to BB this afternoon to check out the Klipsch's. I gave a listen to the RF-62's and 82's. The 82's were really harsh at loud volumes but appreciably more clear than my current onkyo setup. I liked the way the 62 sounded.

I listened to the Def Tech 7004's and was blown away. They really filled the room with sound when listening to a CD I'd brought along. I couldn't have been more impressed. They are expensive, but wow, what an improvement over even the Klipsch's. Anyone know what to look out for if I saved up a while longer and got these instead?

The more and more one looks into this, the more and more one looks to spend... crazy...

Speakers are the most important part of your listening experience. Most people spent too much money on other components and ignore their speakers. The old school rule was that you should spent about 2/3 of your budget on good speakers.

Most Def Tech tower speakers have a separate built-in amp to drive the subwoofer inside. They are also bipolar and tend to fill the room. I have the Def Tech 2000. They have a 15" built-in sub and a 500 watt built-in amp. They were the top of line speakers of the company a few years ago. I would not replace them with anything else on the market. Save your money a while longer and buy the Def Tech. The company also makes other cheaper models.