amplifier question

finite automaton

Golden Member
Apr 30, 2008
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Hello,

I am looking for an amplifier that can do 150W RMS x2 @ 8 ohms OR an amplifier that can be bridged to do 150 RMS x1 @ 8ohms. The cheaper the better, but not if it doesn't sound good.

Thanks,
Bill
 

Tiamat

Lifer
Nov 25, 2003
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What is your budget?

My Rotel RB-1070 does 135W x2 or ~250W bridged. It cost ~$700
 

finite automaton

Golden Member
Apr 30, 2008
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Originally posted by: Tiamat
What is your budget?

My Rotel RB-1070 does 135W x2 or ~250W bridged. It cost ~$700

Well I was hoping to stay around the price range of the Onkyo M-282, ~$200 ($400 if I need two amps).

The speakers I have are capable of 150w RMS. I am afraid the Onkyo will be too weak @ 100w/ch. Am I not going to be able to find a better bang/buck amp than the M-282?
 

PurdueRy

Lifer
Nov 12, 2004
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So wait...have you tried the speakers with your receiver yet? If not then why are you trying to drive your speakers at their max power handling? Do you realize how loud most speakers are if you put 100W into them?
 

herm0016

Diamond Member
Feb 26, 2005
8,510
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watt ratings only mean what they can handle. you will probably have ear bleeding levels well before you get to 100 watts.
 

finite automaton

Golden Member
Apr 30, 2008
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Originally posted by: PurdueRy
So wait...have you tried the speakers with your receiver yet? If not then why are you trying to drive your speakers at their max power handling? Do you realize how loud most speakers are if you put 100W into them?

I have an old Technics SA-290 that we found in my late grandfather's house. It is rated at 50w x2 @ 8 ohms (no idea if it still does it now), but music seems distorted when it is turned up... It is loud, but i'd like it louder :evil:

For the record, the speakers are Klipsch F-3s...
 

Tiamat

Lifer
Nov 25, 2003
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How big is your room and how far are you sitting from the speakers? This will determine how much amplification you need. I doubt your onkyo will be too weak. 100W is quite a bit of headroom for most speakers considering they spend most of their time utilizing at most 1W. If you listen to music at 70dB average, you will be hard pressed to see your speakers draw more than 1-2watts. If you do a lot of movie watching with transients in the 100dB range, then you would probably want to get a bigger amp, but not until after you have tried your onkyo and heard it clipping into the speakers.

Just because the speakers are capable of 150W doesn't mean that is the power you need for your room. That would be the maximum the speakers could accept in a large room with demanding material before the voicecoils cook. There is no reason (except what I just mentioned) why you would need to operate your speakers at the peak of their power handling.

I had less sensitive speakers than you did when I started out (B&W 602s3) and paired it with a 50Wx2 cambridge audio 540A integrated amp. At no moment did the 50x2 amp distort or clip. This was in a 18x12x10 room with very demanding symphonic and pipe organ music played at 75dB average with peaks in the deep bass up through 95dB. The only reason why I moved to the Rotel is because I got a good deal on it and I like the cosmetics :)
 

finite automaton

Golden Member
Apr 30, 2008
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Originally posted by: Tiamat
How big is your room and how far are you sitting from the speakers? This will determine how much amplification you need. I doubt your onkyo will be too weak. 100W is quite a bit of headroom for most speakers considering they spend most of their time utilizing at most 1W. If you listen to music at 70dB average, you will be hard pressed to see your speakers draw more than 1-2watts. If you do a lot of movie watching with transients in the 100dB range, then you would probably want to get a bigger amp, but not until after you have tried your onkyo and heard it clipping into the speakers.

Just because the speakers are capable of 150W doesn't mean that is the power you need for your room. That would be the maximum the speakers could accept in a large room with demanding material before the voicecoils cook. There is no reason (except what I just mentioned) why you would need to operate your speakers at the peak of their power handling.

I'll give that onkyo a shot then. Also, the speakers appear to be setup for biwiring. I've done my reading on it and have decided i'm not going to bother with it unless I have to. My step father wired the current setup to utilize the bottom pair of connectors on each speaker. Does this matter?
 

Tiamat

Lifer
Nov 25, 2003
14,068
5
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Originally posted by: finite automaton
Originally posted by: Tiamat
How big is your room and how far are you sitting from the speakers? This will determine how much amplification you need. I doubt your onkyo will be too weak. 100W is quite a bit of headroom for most speakers considering they spend most of their time utilizing at most 1W. If you listen to music at 70dB average, you will be hard pressed to see your speakers draw more than 1-2watts. If you do a lot of movie watching with transients in the 100dB range, then you would probably want to get a bigger amp, but not until after you have tried your onkyo and heard it clipping into the speakers.

Just because the speakers are capable of 150W doesn't mean that is the power you need for your room. That would be the maximum the speakers could accept in a large room with demanding material before the voicecoils cook. There is no reason (except what I just mentioned) why you would need to operate your speakers at the peak of their power handling.

I'll give that onkyo a shot then. Also, the speakers appear to be setup for biwiring. I've done my reading on it and have decided i'm not going to bother with it unless I have to. My step father wired the current setup to utilize the bottom pair of connectors on each speaker. Does this matter?

I have tried biwiring and found that it didn't alter the sound quality at all. Make sure there is that metal vertical bridge connecting the upper and bottom posts. I think your onkyo should be able to make those F-3 play extremely loudly without any problems. Of course, if you are listening in an auditorium sized room from 30 feet away, both the amplifier and the speaker would not be able to do the job. Even a very high powered amplifier would just cause the speaker to melt trying to fill an auditorium (for example). So, you have to balance the limitations of the speaker and amplifier based on the room, the type of source content, and how far you sit from the speakers.
 

finite automaton

Golden Member
Apr 30, 2008
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Originally posted by: Tiamat
Originally posted by: finite automaton
Originally posted by: Tiamat
How big is your room and how far are you sitting from the speakers? This will determine how much amplification you need. I doubt your onkyo will be too weak. 100W is quite a bit of headroom for most speakers considering they spend most of their time utilizing at most 1W. If you listen to music at 70dB average, you will be hard pressed to see your speakers draw more than 1-2watts. If you do a lot of movie watching with transients in the 100dB range, then you would probably want to get a bigger amp, but not until after you have tried your onkyo and heard it clipping into the speakers.

Just because the speakers are capable of 150W doesn't mean that is the power you need for your room. That would be the maximum the speakers could accept in a large room with demanding material before the voicecoils cook. There is no reason (except what I just mentioned) why you would need to operate your speakers at the peak of their power handling.

I'll give that onkyo a shot then. Also, the speakers appear to be setup for biwiring. I've done my reading on it and have decided i'm not going to bother with it unless I have to. My step father wired the current setup to utilize the bottom pair of connectors on each speaker. Does this matter?

I have tried biwiring and found that it didn't alter the sound quality at all. Make sure there is that metal vertical bridge connecting the upper and bottom posts. I think your onkyo should be able to make those F-3 play extremely loudly without any problems.

Thank you VERY much for the quick info. Those metal bars are there, so I won't worry about it any more. I can't wait to try that onkyo out now :evil:

Edit: Not sure of the room dimensions, but it's definitely going to have no problems being filled by the F-3's.
 

Tiamat

Lifer
Nov 25, 2003
14,068
5
71
Originally posted by: finite automaton
Originally posted by: Tiamat
Originally posted by: finite automaton
Originally posted by: Tiamat
How big is your room and how far are you sitting from the speakers? This will determine how much amplification you need. I doubt your onkyo will be too weak. 100W is quite a bit of headroom for most speakers considering they spend most of their time utilizing at most 1W. If you listen to music at 70dB average, you will be hard pressed to see your speakers draw more than 1-2watts. If you do a lot of movie watching with transients in the 100dB range, then you would probably want to get a bigger amp, but not until after you have tried your onkyo and heard it clipping into the speakers.

Just because the speakers are capable of 150W doesn't mean that is the power you need for your room. That would be the maximum the speakers could accept in a large room with demanding material before the voicecoils cook. There is no reason (except what I just mentioned) why you would need to operate your speakers at the peak of their power handling.

I'll give that onkyo a shot then. Also, the speakers appear to be setup for biwiring. I've done my reading on it and have decided i'm not going to bother with it unless I have to. My step father wired the current setup to utilize the bottom pair of connectors on each speaker. Does this matter?

I have tried biwiring and found that it didn't alter the sound quality at all. Make sure there is that metal vertical bridge connecting the upper and bottom posts. I think your onkyo should be able to make those F-3 play extremely loudly without any problems.

Thank you VERY much for the quick info. Those metal bars are there, so I won't worry about it any more. I can't wait to try that onkyo out now :evil:

Just so you know, if you don't have the metal bars in (just by accident for example), then the tweeters won't get any power. So, if one day your speakers sound very weird, just check the wires in the back and also, check the bars to make sure they are tight.
 

PurdueRy

Lifer
Nov 12, 2004
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Originally posted by: finite automaton
Originally posted by: PurdueRy
So wait...have you tried the speakers with your receiver yet? If not then why are you trying to drive your speakers at their max power handling? Do you realize how loud most speakers are if you put 100W into them?

I have an old Technics SA-290 that we found in my late grandfather's house. It is rated at 50w x2 @ 8 ohms (no idea if it still does it now), but music seems distorted when it is turned up... It is loud, but i'd like it louder :evil:

For the record, the speakers are Klipsch F-3s...

It distorted because Technics is a cheap brand and that 50W rating is likely under ideal conditions. It is likely a VERY low output amplfier section before increasing THD beyond 1%.

I doubt that you will find need initially for anything beyond the Onkyo.
 

Rubycon

Madame President
Aug 10, 2005
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Originally posted by: PurdueRy

It distorted because Technics is a cheap brand and that 50W rating is likely under ideal conditions. It is likely a VERY low output amplfier section before increasing THD beyond 1%.

I doubt that you will find need initially for anything beyond the Onkyo.

Actually that is quite wrong! Technics SA series (early '80's) were quite good! HOWEVER The 290 was HORRIBLE for output compared to the SA-203. I know because this was during my college days and I had an SA-203 Text - and it was the best sounding 30WPC in a small package and price I heard! A friend of mine loved it and he bought the 290 and immediately blamed his speakers so we connected my 203 and he could not believe his ears! I'd be willing to bet that's your problem though. Those receivers (now vintage - sigh I am getting old! :( ) - were very good quality parts back in the day.

If you like to play things loud I'd recommend a receiver with pre amp outs, use an unbalanced to balanced converter (DI box similar) and find a used crown/yamaha/qsc amp at 300+ wpc to drive your mains. The extra headroom will sound great and will not harm your speakers in any way providing you're not listening to highly compressed modern recordings at ear shattering levels. ;)
 

cheesehead

Lifer
Aug 11, 2000
10,079
0
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Originally posted by: Rubycon

If you like to play things loud I'd recommend a receiver with pre amp outs, use an unbalanced to balanced converter (DI box similar) and find a used crown/yamaha/qsc amp at 300+ wpc to drive your mains. The extra headroom will sound great and will not harm your speakers in any way providing you're not listening to highly compressed modern recordings at ear shattering levels. ;)


Pro-audio gear is headache-inducingly complicated. Why not just use the same impedance for everything?

http://www.provideosound.com/art-dti.html
 

alcoholbob

Diamond Member
May 24, 2005
6,380
448
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150W will give you more headroom, and push out the clipping wall.

Even craig chase, the guy who builds small portable, low-powered amps at tweakcity audio says it. A few watts goes a long way, which is why he made his amps a little bit more capable than your standard Class-T fare. He says he hears the arguement all the time "well its just another 3db for this much power, its just..." this thing goes ad infinitum and you may as well just run a 1W tube amp and enjoy your clipping at 90db.
 

Rubycon

Madame President
Aug 10, 2005
17,768
485
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Originally posted by: Astrallite
150W will give you more headroom, and push out the clipping wall.

Even craig chase, the guy who builds small portable, low-powered amps at tweakcity audio says it. A few watts goes a long way, which is why he made his amps a little bit more capable than your standard Class-T fare. He says he hears the arguement all the time "well its just another 3db for this much power, its just..." this thing goes ad infinitum and you may as well just run a 1W tube amp and enjoy your clipping at 90db.

If the speaker is not efficient no amplifier can make up for it, period. This is why reinforcement applications push for highest efficiency. A 1W tube amp can play ridiculously loud into a fully horn loaded speaker. (105-110 dB SPL) A more typical 88dB loudspeaker will play well 88dB. :laugh:
 

finite automaton

Golden Member
Apr 30, 2008
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Thank you all for the input. The onkyo amp was supposed to get here today but it didn't make it :( The SA-290 does clip very quickly, I hope that problem is solved with the amp.