Should I get a power amp??

CB22

CB22

Senior Audioholic
I recently bought an Anthem 720 MRX receiver and love it. Great up-grade from the old crappy Dennon. Considering purchasing a power amp for for my three main channels. The reason I am thinking about is that I was watching a blu-ray coming out of an Xbox and had the volume at -7db. (the movie sounded fairly loud) The anthem maxes out at 0db. I would like some extra head room but is it worth the money? The power rating for these main speakers are 250w/ with a 600w peak. Not sure the wattage anthem is putting out with 5 channels driven. Would it be worth purchasing power amplifier? If so what are your recommendations. Save up for a Anthem MCR ($800 per channel) or go with something else like an XPA-3 ($400 per channel)? Or not spend any money.

The set up:
Klipsch RP - 280Fs (x2)
Klipsch RP 450c Klipsch
RP 160M (x2)
+ 2 rpw-10 subs
Any advice would be much appreciated thanks.
 
WaynePflughaupt

WaynePflughaupt

Audioholic Samurai

Save your money. Klipsch speakers are super-efficient and don’t need much power compared to other speakers.

Regards,
Wayne A. Pflughaupt
 
lovinthehd

lovinthehd

Audioholic Jedi
Well, I'd take my Denon over your Anthem for amp power, but try using an spl calculator to get an idea what an amp would do with your speakers....
 
KEW

KEW

Audioholic Overlord
Most likely you have plenty (as in "gobs") of headroom.
If you ran the set-up process built into your AVR, that sets the volume relative to reference level. Consequently, even though you have the volume at -7dB, that is referring to how loud it is in your room. With efficient speakers like Klipsch, 140 watts per channel is way more than you need unless you want to blow your speakers (and/or your ears)!
However, you should check your menu settings to see if their is a volume setting you can change. On Denon and Marantz units you can choose to have a limiter at -20dB, -10dB, 0dB, or Off. In the off setting, the volume will register up to +18dB. I suspect your Anthem has a similar feature and 0dB is the default setting. Not many people are going to want to listen at over 0dB and lots of speakers will blow drivers at +18dB.
 
KEW

KEW

Audioholic Overlord
If you want to verify what I am suggesting about headroom, you can perform a "factory reset" on your AVR. That will "erase" the volume calibration relative to reference level and you should find that you have more volume than you know what to do with!

What model Denon did you have and what was crappy about it?
Denon generally makes a good solid unit and we don't hear many complaints.
 
CB22

CB22

Senior Audioholic
Thanks for the tips! I'll will most certainly try the factory re-set and look though the menus more. Interestingly enough when I've been listening to music at a reasonable volume the receiver is showing -35db when when I switch it over the the movies I crank it up to around -10db.

To answer your question I had a AVR-S510BT that I bought about two years ago I think (Which, the sales man at Best Buy said this was the best bang for your buck). When I set everything up I heard a nice little hiss though all the speakers. Go figure I had already threw away the box for it. Also there were no banana plugs connections on this model. Originally had the floor standing speakers paired with a Marantz stereo amp and loved it. Simply put the receiver was messing with my speakers. Finally I said screw it, did my re-search and got the Anthem about three months ago.
 
lovinthehd

lovinthehd

Audioholic Jedi
Well, the 510BT is pretty much their bottom of the line. I looked thru your 720 manual and there is a setting for maximum volume but it didn't say what the various settings were...
 
Y

yepimonfire

Audioholic Samurai
I recently bought an Anthem 720 MRX receiver and love it. Great up-grade from the old crappy Dennon. Considering purchasing a power amp for for my three main channels. The reason I am thinking about is that I was watching a blu-ray coming out of an Xbox and had the volume at -7db. (the movie sounded fairly loud) The anthem maxes out at 0db. I would like some extra head room but is it worth the money? The power rating for these main speakers are 250w/ with a 600w peak. Not sure the wattage anthem is putting out with 5 channels driven. Would it be worth purchasing power amplifier? If so what are your recommendations. Save up for a Anthem MCR ($800 per channel) or go with something else like an XPA-3 ($400 per channel)? Or not spend any money.

The set up:
Klipsch RP - 280Fs (x2)
Klipsch RP 450c Klipsch
RP 160M (x2)
+ 2 rpw-10 subs
Any advice would be much appreciated thanks.
Save your money. I have RP150ms and a 250c for my fronts, R-15ms for surrounds, and RB-10s for my heights, with this setup I have measured maximum spl readings of 110dB during loud portions of movies. I can easily get reference volume with a cheap onkyo TX nr656 sitting 11’ away.

Your 280fs will likely hit reference levels with 50w or even less depending on the room size. As you’ve noticed, most people listen at about -15dB to -5dB, at -10dB, if the speakers have been properly calibrated to 75dB with the internal -30dBfs pink noise, you need enough power to drive each speaker to 95dB at the mlp. In my room, this only requires about 20w, with your 280fs, even if you sat 12’ away, that’s only 10w, for full blown reference volume, you still only need about 70w. I’d be more worried about your sub being able to keep up with your speakers.


Sent from my iPhone using Tapatalk
 
Last edited:
Verdinut

Verdinut

Audioholic Spartan
If there's a volume adjustment on the XBox, it should be set to maximum.

Also, should there be a source level adjustment in your receiver, and it's set to -10 as an example, levels could be increased and that would help the situation and provide more headroom.
 
Y

yepimonfire

Audioholic Samurai
If there's a volume adjustment on the XBox, it should be set to maximum.

Also, should there be a source level adjustment in your receiver, and it's set to -10 as an example, levels could be increased and that would help the situation and provide more headroom.
I’m guessing the receiver isn’t properly calibrated, 0dB should be a peak per channel of 105dB and 115dB on the sub.

With 5 channels blaring along with the sub, that’s almost 120dB peak. While reference levels aren’t actually dangerous when it comes to movies (I’ve actually measured the time weighted average in dBA for a loud 2 hr movie, amounts to some 3% daily dose), playing above these levels is dangerous.

Even with two channels, +10dB on the volume knob is 117dB peak, even at 105dBA for only 15min, (which 117dBC might translate to) this is 320% of a safe daily dose according to NIOSH guidelines, and will certainly equate to hearing loss. Peak dBA measurements during movies played at reference levels only hit about 95dB max for brief periods. Even if the movies had 30 minutes of 95 dBA sound and 1.5hrs of 75 dBA (ie interstellar), this is still only 65% of a TWA daily dose, and not dangerous at all.


Sent from my iPhone using Tapatalk
 
CB22

CB22

Senior Audioholic
A couple things:
1st: I did find the maximum volume in the menu and changed from 0db to +10db. (the manual states that this is so not to lose your hearing. lol)
2nd: The Xbox audio settings are on "Bit stream out", "DTS audio" , and there's a setting checked that says "Let receiver decode audio."
3rd: I have yet to find the "source level adjustment setting" -> there is a setting that says, "calibration speaker levels," which has the test tone settings. The three fonts are set to "-2db" and the back to speakers are set to "-1" (The room correction came up with these settings)
4th: I did use the ARC room correction when setting up the receiver. I have not re-set to the factory settings yet but will give it a try tonight and test a movie to see if there's more head room.

Lastly when I got the receiver the only two big changes I made were to update the firmware and run the room corrections.
 
CB22

CB22

Senior Audioholic
Also you fellas have any suggestions on how to properly calibrate a receiver?
 
Verdinut

Verdinut

Audioholic Spartan
What I suggest is that you should thoroughly read your Owner's Manual where you will find most of your answers.
 
CB22

CB22

Senior Audioholic
Yes, I have read though it once. But will give it another read.
 
panteragstk

panteragstk

Audioholic Warlord
I would also see if there are any ARC threads on AVS. They usually have detailed instructions that go outside the manual that can get you very good results.
 
lovinthehd

lovinthehd

Audioholic Jedi
A couple things:
1st: I did find the maximum volume in the menu and changed from 0db to +10db. (the manual states that this is so not to lose your hearing. lol)
2nd: The Xbox audio settings are on "Bit stream out", "DTS audio" , and there's a setting checked that says "Let receiver decode audio."
3rd: I have yet to find the "source level adjustment setting" -> there is a setting that says, "calibration speaker levels," which has the test tone settings. The three fonts are set to "-2db" and the back to speakers are set to "-1" (The room correction came up with these settings)
4th: I did use the ARC room correction when setting up the receiver. I have not re-set to the factory settings yet but will give it a try tonight and test a movie to see if there's more head room.

Lastly when I got the receiver the only two big changes I made were to update the firmware and run the room corrections.
I wouldn't bother with a factory reset since you already found the max volume settings (which was the suggestion earlier to resolve the max setting). Not sure what your expectation is with more headroom, tho, if you turn it up even more you'll have less.

Maybe re-run ARC after reading up on methods. ARC is a good way to calibrate your setup, or you can do it manually if you have the tools (measurement mic and software or an spl meter) and your manual probably has guidelines for that. Your Denon didn't have Audyssey which may be a reason you like the Anthem better...

A quick glance at the manual I didn't find input level mentioned in input setup but didn't RTWFM. :)
 
KEW

KEW

Audioholic Overlord
4th: ...I have not re-set to the factory settings yet but will give it a try tonight and test a movie to see if there's more head room.
I just want to be sure that you understand! The factory reset will not gain you any headroom! What it will do is revert the volume control to the full scale.
When you run the setup, it scales the volume to Reference level. With Klipsch, it is a safe bet that means 0dB or even +10dB is well below the AVR's maximum power output! However, you still have the full power of the AVR available for any peaks.

If you feel like the headroom is being limited (based on what you hear), one possibility is that there is processing to compress the audio so the loudest and softest levels are not too far apart. This is often used for late night listening where you do not want sudden loud sounds disturbing anyone (or soft whispers to be lost because you have the volume down).
In the Marantz/Denon world, Audyssey Dynamic Volume does this, plus there is a "Low Frequency Containment" setting which is designed to taper back the low frequencies (which will be obnoxious if transmitted to apartment neighbors late at night) which would also "castrate" your system!
I am sure Anthem will have other names for these features, if present, but this might help you recognize what might be relevant as you look through your manual.
 
Last edited:
KEW

KEW

Audioholic Overlord
Thanks for the tips! I'll will most certainly try the factory re-set and look though the menus more. Interestingly enough when I've been listening to music at a reasonable volume the receiver is showing -35db when when I switch it over the the movies I crank it up to around -10db.
I think this is really the issue. There should not be a 25dB disparity depending on which source you are using! Try to find the source level adjustments and see if there is a way to raise the volume coming from your xbox like Verdinut suggested!
 
mtrycrafts

mtrycrafts

Seriously, I have no life.
I think this is really the issue. There should not be a 25dB disparity depending on which source you are using! Try to find the source level adjustments and see if there is a way to raise the volume coming from your xbox like Verdinut suggested!
Yes, that sound like his issue but CDs are recorded at a higher average level vs movies.
I encounter this as well, CD is very loud at the same indicated volume level from movies.
 
KEW

KEW

Audioholic Overlord
Yes, that sound like his issue but CDs are recorded at a higher average level vs movies.
I encounter this as well, CD is very loud at the same indicated volume level from movies.
I must admit I have not bothered to adjust my own source levels, but that is because I typically listen to CD's at around -35dB and listen to movies at around -27dB. IOW when I switch between formats it is not overbearing loud or so quiet that I feel the need to mess with these settings. I am OCD in some ways, but not on this count. I am more annoyed by the difference in volume between a CD from the 80's vs a new one!

What type of difference do you see between CD's and movies regarding where you set the volume knob?
 
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