Which amp is right for me?

Telemundo

Hi, I'm really new to this Home audio field. I just bought the Harman Kardon AVR230 receiver. I've seen alot of people talking about how speakers are more likely to break down from having too little power than having too much. My AVR230 only at most outputs 50 watts x 6 channels. In that sense, does this mean my receiver is more likely to cause problems? I'm planning on getting the RTi8 for fronts, CSi5 for center, FXi3 for surrounds, CSi3 for rear, and maybe the SVS PCi20-39 for sub. What is bi-amping exactly? Will bi-amping help my receiver's output wattage problem? Can I use the Harman Kardon PA2000 amp and AVR230 to power the speakers? Would the PA2000 be a good compliment to the receiver? Please let me know what's the best I should do? Thank you for taking the time and reading this.

steveinaz

>>My AVR230 only at most outputs 50 watts x 6 channels. In that sense, does this mean my receiver is more likely to cause problems?<<

That depends on 2 things:

1. The efficiency rating of your speakers
2. How loud you listen

Clipping distortion is what you may run into when pushing the amp beyond its clean power output. Ways to avoid damage? Don't push your system too hard; upgrade the receiver. You should never consider anything below 100watts/rms--even for the most conservative listener.

Ceruleance

Originally posted by steveinaz
>>You should never consider anything below 100watts/rms--even for the most conservative listener.

boy that is some bad advice..
The 230 is a very capable receiver (my friends system has a 225 in it, very similar) You cannot really trust manufacturer's wattage ratings, especially in the lower cost receivers. Your H/K will almost definitely outperform one of those cheapo receivers they sell for $200 bucks at best buy but advertise as having 100 wpc.

the first thing he said is true, it depends on the efficiency of your speakers

the 8's are 90 dB/watt/meter, which means with a comfortable 6 db of headroom, your 50 wpc H/K will be able to push them over 100 dB, which is very very loud.

I wouldnt buy the PA2000 right now until you have tryed this setup. If you have a very large room or listen at crazy volumes then you might need more power, but it would be my best guess that you are in the clear for now.

Two things will happen if you don't have enough power 1. your receiver will go into thermal protect mode, or 2. I am pretty sure you will be able to hear it if your speakers are clipping. If either of these happens FREQUENTLY, and the 230 is being properly vented, then come back and we will recommend you an amplifier (the PA2000 if you really like it)

Once again, try it out, and if it doesnt work then you can think about adding amps or something. Your proposed system will sound great.

If I were you and I could afford it, I would consider the 330, 430, or 630. For one thing, you get the added 7th channel, and the more power you have the more headroom you have and generally the better it will sound. (let me restate this so you aren't confused, yes more power will sound better, but the 230 has enough power to push your speakers to loud levels without risking damage to them). The new prices of these units might scare you off, so maybe you should consider a used or demo unit of last year's model, the AVR525. You should be able to get one for around $500, it has more power, and a 7th channel. (I use the 525 and it's great)

Telemundo

thanks for reading spending so much time with the reply. If you said the AVR 230 can push the RTi8s, CSi5, FXi3, and CSi3 just fine and it would sound great with movies then I'll believe you. Have you heard the AVR 230 vs. the AVR 525? Would you still recommend the 525 over the 230, even though it's older? Thank you once again for offering your advice.

Tour2ma

Originally posted by Ceruleance
the 8's are 90 dB/watt/meter, which means with a comfortable 6 db of headroom, your 50 wpc H/K will be able to push them over 100 dB, which is very very loud.

only true if you sit 2 meters from the 8's.

since sound radiates hemispherically within the boundaries of the room it's in, the spl from one source decreases as the square of the distance multiple. adding the second channel regains 3 dB.

so at a typical distance of 12' or ~4 meters (4x the distance), the net spl loss is 9 dB. so not only is the apparent headroom under rated output gone, but the amp will be clipping at 100 dB.

but not to despair... if the svs is assigned the duties below 80 Hz and with three more channels being driven (up to 9 more dB), the 6 x 50 can be adequate... if you do not listen too loud.

moving to 100 wpc only buys 3 dB over a 50 wpc...

Dr. Spec

Yep, the h/k has a beefy little power amp section.

Set all the speaks to small at 80 Hz and send the SVS the rest.

It will have plenty of power/volume in a high passed application in a moderate size room.

Bass is what sucks the life from an amp section. That is why your sub packs 320 watts continuous - so your h/k doesn't have to.

If you never run any of your channels on full range (large), I doubt you'll ever notice you have "only" 50 watts per channel.

steveinaz

You should never consider anything below 100watts/rms--even for the most conservative listener.

I stand by this. The dynamic range available on CD's and DVD's necessitates greater dynamic headroom. I realize you may be using a powered sub, which will take alot of the strain off the receiver, but it's not distorted low frequencies that cause problems; its distorted high frequencies.

I can almost guarantee you'll be replacing tweeters within 6 months.

Ceruleance

Originally posted by steveinaz

I can almost guarantee you'll be replacing tweeters within 6 months.

boy steve, you are just out to scare this guy aren't you..

regardless hopefully tele- will realize that several people think it will work and one person is just bitching

tour, i realized i was leaving out distance because I was being lazy about it, but you also have to take into account that it's 6 speakers w/ 55 watts, not just two. What's the rule for more than 2? 3 dB each speaker still? Regardless, I was trying to make a point, and steve would have never noticed

Tour2ma

Originally posted by Ceruleance
tour, ... you also have to take into account that it's 6 speakers w/ 55 watts, not just two.

actually I did...

While I agree that Steve's being a little dramatic here, I have always bought the most power I can afford. And these days it's pretty affordable...

Tour2ma

Originally posted by steveinaz
but it's not distorted low frequencies that cause problems; its distorted high frequencies.

ummmm, no... or at least not exactly. may just be symantics, but i don't think of clipping as distortion.

clipping of any music signal generates high frequency signals on the order of 100k Hz that tweeters try to reproduce and the resulting heat generated.

Telemundo

so...what's the verdict here? It seems like u guys are giving me 2 opposite opinions here. I dont wanna have to send the speakers out for replacing within a year of having it. My room size is only 13x10. it's not a huge room, but sometimes i'd like to play my movies pretty loud. i'm just getting more confused, because some people tell me it's fine...some people tell me that AVR230 isnt gonna cut it. man...

Ceruleance

I think you would get a better value if you went with one of the older models, 525 or 325. First of all you get the 7th channel, second of all its just cheaper. Unless there is a feature H/K has added with the *30 line up that you really like (I cant think of any at the moment) and you can live with the slightly less cool black face as opposed to the new silver, I would go with a *25 model. For the price of a new 230 I think you can get a used or demo 525. Whichever receiver you decide on, you can always add more power with another amp, so don't feel like you are going to be completely out in the cold if it turns out it's not enough power.
ok well other people may have their bottom lines but here's mine:

1: Ok definitely with that room size I REALLY doubt you are going to break anything, even if you do push the volume really really loud. Hey **** happens though, right?

2: As tour said, its sometimes a good idea to buy the most power you can afford. I mean on the one hand I am telling you that the 230 will work for your setup, but if it were my decision to make (and it was not so long ago) I'd just get the best in my reasonable price range. For me that meant going with a used unit in order to fit in under my budget. $1100 for a new 630 is a far cry from $500 for a used 525..

Telemundo

but if i was to add a amp in the future...most of the amps that are in the reasonable price range(200-500) only has about 50w x 2 channels i think, so does that mean i have to get 2 of them to drive to 2 speakers in the back also? or do i have to spend more to get one that drive 5 channels? also, one of my friend told me that he'd let me borrow one of his car amps, is car amp safe to use with home speakers? jus as long the ohms match rite? or do you know of an amp that's is good that u'd recommend...thank you

Ceruleance

there are many amps in the sub 500 category that will fit the bill and many have more than 50 watts. Especially if you look for used stuff. The PA2000 you mentioned is 2 x 100 and is only like $250. You absolutely cannot use car equip. in your home.

Tour2ma

1st - more than one opinion is to be expected. if you're lucky you only get two different ones 'round here...

2nd - loud listening is relative. normally 95 dB 2 ch music is loud to me and 75 dB "conversation" levels is normal for dvd's. in either case 100dB transients are likely, but not much more. in your size room (just over 1000 cu ft) these levels should be ok for your 50 wpc avr IF speakers are set to small and crossed to the sub at 80 Hz.

but sometimes I like to push "a liitle" harder... and you probably won't be able to without clipping occurring.

so basically I'm agreeing with Cer, but will also offer the same proviso... push too hard and you will clip your amp...

steveinaz

>>may just be symantics, but i don't think of clipping as distortion<<

Clipping isn't distortion, but it does most certainly cause incredible amounts of distortion. Take a look at any power output vs distortion graph, and you'll see THD increase dramatically at clipping. This is what causes the ultrasonic frequencies that damage tweeters.

I'm recommending more power to him because rather than wasting money going thru amps/receivers, I think it's better to start with something that will hold him for awhile. I think he'll find that as the fidelity of system gets better, he'll be using more power.

Just like motorcycles--I would never tell anyone to buy a 250cc motorcycle--why? Because as you get accustomed to the power, you'll grow tired of it quickly. Does a 250cc get you from point A to point B, yes; just not very efficiently, nor with much thrill factor.

Just trying to save him a little money in the long run.

steveinaz

>>regardless hopefully tele- will realize that several people think it will work and one person is just bitching<<

bitching?
Forums are all about opinions on differing situations. You've got your opinion, and I've got mine--Let this member take in the information provided by all of us, and make his own decision based on what he feels is important. If everyone is just going to echo everyone elses sentiments, it doesn't do much good to ask for opinions, does it?

Power is relatively inexpensive these days, so in that light, I recommended he get at least 100 watts, why? because it'll provide a little more headroom for dynamic passages, and might cost him $150 more than a comparable 50 watt amp.

Tour2ma

Originally posted by steveinaz
Clipping isn't distortion, but it does most certainly cause incredible amounts of distortion. Take a look at any power output vs distortion graph, and you'll see THD increase dramatically at clipping. This is what causes the ultrasonic frequencies that damage tweeters.

true that thd rises as you run out on an amp's power curve, but my understanding is that the ultrasonic signals produced as a result of clipping have a different source. namely the peak of the transient that cannot be reproduced due to exhaution of the power available.

btw, i don't consider your stance "bitching". however, i do not endorse your 100 wpc stance as an absolute. under some circumstances less power will do just fine and in tele's case it will.. imo...

shack

Originally posted by Tour2ma
btw, i don't consider your stance "bitching". however, i do not endorse your 100 wpc stance as an absolute. under some circumstances less power will do just fine and in tele's case it will.. imo...

Totally agree...and remember that all 100w are not necessarily the same. examples:

Outlaw 1050 = 65wpc X6

Rotel RSX 1055 = 75wpc X5

NAD T752 = 80wpc X5

Just 3 examples of AVRs that I have heard that will push most any speaker in a moderate size room as loud and clean as you want to go. High current with the ability to drive 4ohm easily.

And in Telemundo's case the Polks he is going to use are very efficient and easy to drive. Could he use more power...yes...but he may not need to. His room and speakers probably mean the HK 230 will do just fine. I run a very modest Denon AVR (80wpc X5) for my HT in a VERY large room (29' x 24' x 8') and I never come close to using all the power even with demanding discs.
(plus I have my mains and center set to large).

Ceruleance

Steve,
You are presenting two different arguments. You give the metaphor of motorcycle's: That you would never recommend someone a 250cc, even though you acknowledge that it will get them from A to B. But before you said you are BETTING that the receiver will break his speakers... clearly saying that the receiver he is considering will not get the job done.

In one case you are saying that you recommend more power just because he will want it later. That's fine, I think tour and I even agree. But that wasn't what you were saying earlier. You changed your stance after I accused you of bitching.

At first you were saying that you recommend more power so he doesn't break something. So then Tour and I go through the equations to make a point that he will more than likely not have a problem, and you rebuttal with "I still think he will have a problem" just a blank statement. That I consider bitching. The absolute SPL he can obtain in his particular situation is not an opinion question. Obviously we are all estimating, so if you have a better estimate then by all means, but I didn't seem to think that was your argument..

On another note:

In terms of not recommending more power, at some point if everyone who comes here gets told, "oh yes nothing in your budget is satisfactory even though you have efficient speakers and a small room", that's not really being helpful... and in terms of the H/K line, small increases in power are really going to add up if you look at the incremental differences in wattage and the price jump for each of those increases, with roughly the same features.

Tour, btw, now that we know the size of his room I think it's safe to assume his listening position isn't 4m anymore, 3m is probably the max, and a factor of 9 reduction is much less substantial than a factor of 16.

Tour2ma

Originally posted by Ceruleance
Tour, btw, now that we know the size of his room I think it's safe to assume his listening position isn't 4m anymore, 3m is probably the max, and a factor of 9 reduction is much less substantial than a factor of 16.

true, but the math is tougher...

steveinaz

I wouldn't recommend a 50 watt amp to anyone, under any circumstance, who likes to listen to digital sources regularly.

Dialog on DVD's can have you reaching for the volume knob--and then BAM! here's comes a cool explosion. A good one is the DVD "Silverado"; it has a number of explosive transitions that go from a whisper to a gunfight in a millisecond.

My 30yrs of audio experience has taught me that you get as much amp as you can afford--high quality clean power. If this means you have to wait until next year for that big screen, then you wait. I have a 205 watt Parasound amp that really earns its money when playing DVD's---and I don't listen particularly loud when watching movies. I can't even fathom doing that with 50 watts.

...and by the way, the only tweeter I ever blew in 30 yrs was an AR9Lsi tweeter when powered by a Pioneer A9 (Circa 1982)Integrated amp; 80 watts/rms. Since then I've never owned an amp under 205 watts.rms....and I've never blown another tweeter.

Tour2ma

sure... but you'd recommend a 100 wpc...

Ceruleance

explosions are usually handled by a subwoofer with it's own outboard amp.

I have a parasound with 350 wpc. I've never blown a tweeter. Maybe that means the magic number for not blowing tweeters is 350 watts?

I think im gonna bow out of the basic forum discussions for awhile..

Telemundo

Hi, i didnt mean to get your guys into any kinda heat with each other...i just wanted some of your expert opinions. I do appreciate you guys for taking the time, doing the math, and giving me the advices. I've made up my mind and that i'm gonna get the AVR630 for $820 from one of the authorized online retailers. Steveinaz, thanks for your advice. I know myself pretty well that if i kept the AVR230, eventually i'm gonna want more powerful AVRs. but if i wait too long, i wont be able to get a refund on the AVR230, that's why i'm gonna return it before even testing it out. Like u said it's better to have a little too much power than not enough. And in the H/K's case, 75 wpc isnt that much more than the 50 wpc. but more is always better. love the design of the new AVR '30s line by H/K. Thanks alot guys, once the parts are all here and i'm finished setting it up, I'll post some pics of it on the site.
PS. I'm sure u guys will see me around some more. I'm sure i'd have more technical questions for you guys about setting it up.

Tour2ma

no problem... we really were only disagreeing over the existance of absolutes. we all agree more is better. how much is enough and where, if anywhere, you have too much are points of contention.

you're buying yourself a little insurance with the move up, but just a little, so still be a little cautious.

enjoy your new gear.

steveinaz

No heat involved, just differing opinions. I respect the other guys opinions as they have much merit to thier respective views. I'm just offering another point-of-view.

Ceruleance

Yes, all is well at club polk. Stick around and ask questions, you will learn a lot

Violator

First of all I would just like to inform everyone of the power capablility of the harman kardon. I dont have the new 230. but i have last years verson 225. Here is some food for thought.
My dad has a kenwood reciever with 600 watts. thats 100x6. His reciever has 2.8amps. My harman is 55x5 which is only 275 watts. The difference is i have 28 amps in my reciever. Dont listen to people who say the more watts the better. Right now i have two polk rti70 + 2 rti38 bookshelf + 2 paragon pro series 250 watt speakers. With a cerwin vega 12 inch sub.. All together thats 1600 watts i have hooked up to this recierver. I need an amp but not badly. this reciever sounds good and really really really loud at the volume setting 10. It sounds bad after that. I need an amp. You dont with your speakers because of less wattage. but my point is that the amps power the watt. The more amp the more watts. If you figure this out in mathimatical terms just for fun. Im gonna say 2.8 amps * 600 watts = 1680 now 28 amps in my hk * 275 = 7700. Now this isnt an equation of watts or anything. The numbers just show u the overall power. As you can see the hk has much more power. Im very happy with my recierver

another thing u could do to get more power to your speakers is get 16 guage wires. My whole system was wired with 10 guage wires and it didnt have much power. The wires create much resistance. I switched to 16 and i have soooo much more power and the clarity is much better. If you have a powerful amp and reciever then use bigger wires than 16 guage but in my case i only have the reciever so 16 is ideal for me. If you have any questions just reply under here....


Scott the Genius

shack

It's all so clear now....

Tour2ma

I agree... I've never seen it put quite that way before...