View Full Version : What is stronger?????
HelpMeOut
08-24-2004, 05:26 AM
If a receiver has a 135 watt x 5 @ 8 ohm and an amplifier has 105 watt x 5 @ 8 ohm, which one is stronger? Should I just use the amplifier from the receiver for the speakers or should I wired the amplifier to the receiver and then use the amplifier itself? THANKS!
Resident Loser
08-24-2004, 07:00 AM
...if both are RMS ratings, the diff is negligible, power-wise...other specs like current output or dynamic headroom and damping factor should be taken into consideration...how each might handle the load presented by the speakers may be an issue...perhaps one may present a more pleasing presentation....some aspects to consider might be quite subjective in nature.
Then of course, we have the question: does the reciever even have the facilities to be wired to an outboard amp? I don't purport to be some sort of know-it-all re: multi- channel/HT gear, but in my limited experience, my guess would be it probably doesn't.
jimHJJ(...sooo???...)
Pat D
08-24-2004, 07:24 AM
If a receiver has a 135 watt x 5 @ 8 ohm and an amplifier has 105 watt x 5 @ 8 ohm, which one is stronger? Should I just use the amplifier from the receiver for the speakers or should I wired the amplifier to the receiver and then use the amplifier itself? THANKS!
That's hard to say. As a practical matter, does your receiver have adequate power for your needs? If so, why worry about a separate amp, which would have to be considerably more powerful to make much difference?
There is an ambiguity in the specifications, of course. Does 100 watts X 5 mean each channel individually can produce 100 watts into 8 ohms? That's a usual interpretation. Or does it mean that each channel can produce 100 watts into 8 ohms when all 5 channels are driven simultaneously? That's much more difficult and it seems many receivers can't do that, and some don't even come close. Sound & Vision magazine has measured that kind of thing, and a fellow named Phil has put many of their test results in a spreadsheet for our convenience:
http://www.geocities.com/Area51/Hollow/3401/ratevsac.htm
Most receivers have a single power supply for all channels, and so of course, if only a channel or two are driven, they can produce more power than if all the channels are driven to high levels. That does not seem to occur too often in actual movies, so I imagine most receivers satisfy most users.
Some separate amplifiers have fairly hefty power supplies and some don't. So the same considerations apply.
HelpMeOut
08-24-2004, 04:05 PM
The receiver I'm talking about is a Denon AVR5600 and the amp I'm talking about is a Denon POA-8300. So which way should I go with? Use the receiver by itself or run the amp with the receiver? Thanks for your input Resident Loser and Pat D.
markw
08-24-2004, 06:46 PM
See how the receiver works. If you think you are having a power problem, then try the separate amp.
Remember, for a barely noticable increase of 3 db in headroom you must double the power.
So, even with allowing for the possibility that the separate amp just might (notice the "might") have a little more "real" power when all channels are driven to the max simultaneously for extended periods (which is rare for HT), you would still need need twice the power of the initial reciever for a barely noticable difference.
Even with all the weasel words in the above paragraph, I simply don't see that happenin' here. I'd give real careful thought here unless spending money or simply having a separate amp is the main goal.
HelpMeOut
08-24-2004, 07:09 PM
THANKS for your input Mark. I have both the receiver (denon avr5600) and the amp (denon poa-8300) in my possession already. I just need to know which way should I set it up. Could I use the receiver (denon avr5600) as a preamp to run the denon poa-8300 amplifier? I'll be using a set of Infinity IL50 speakers and maybe a center channel. Is this system good for karaoke? That's what I use my system for most of the time. THANKS!!!
s dog
08-24-2004, 10:20 PM
I was looking at the denon website and it shows the denon poa-8300 amp as a 120 watts x 3, i have the denon 4800 i got a 120 watt x 2 sonance amp running my mains and the denon 4800 running side surrounds and back surrounds and center , when running 2 channel stereo useing the sonace vs 4800 i hear no differents, the denon has 125 watt per channel, but if you already have the amp i would use it , might take some of the load off the denon
HelpMeOut
08-25-2004, 04:54 AM
Thanks s dog. So how can I wired all these components together? A receiver Denon AVR5600, an amplifier POA-8300, a Sony DVD player, and a karaoke mixer?
Resident Loser
08-25-2004, 08:41 AM
...well, now that I have that bit of editorializing done with....
As the only info I can find is spotty at best(the Denon site does not have PDFs on the 5600 OR the 8300)...we'll take some educated guesses based on the 5700, the model that superceded it...Additionally, and as has been stated previously, the POA 8300 is only a three-channel unit rated @120wpc 20-20kHz, no impedance stated(Denon's archives are incomplete at best)...
Simple, basic connections should be:
From the receiver's "pre-out" jacks, connect RCA cables to the amps inputs...
Connect your DVD player's outputs to the receiver's appropriate inputs...they all should be clearly marked...
For the "mixer"...simply connect RCAs from its' output to, I'd guess the "tape 1" input; it may be more forgiving in mismatches and overload characteristics...do not use "phono in" as the RIAA equalization in the phono preamp section is dedicated for vinyl playback...This, of course, is assuming the "mixer" is just a mic input...
If, however, the DVD is providing a display of song lyrics to your teevee or video monitor in addition to the soundtrack...you may have to connect it through your "mixer" and that output to the reciever's DVD inputs...it's difficult to be accurate with less than perfect info and in lieu of "hands-on" trial and error...
For anything fancier, I'd suggest consulting the appropriate owners manuals...
jimHJJ(...good luck...)
piece-it pete
08-25-2004, 08:57 AM
As far as which amp section to use I'd try both, and use setup that sounds better to you.
It might be noticable.
Pete
HelpMeOut
08-25-2004, 05:28 PM
Thanks Jim and Pete. The connection you (Jim) described to me is exactly what I had in mind but I'm an electronic dummy so hearing from you is a plus. Do you have in mind a better combination of components that I could put together for a great karaoke system Jim? A pre-amp? Another amp? Another set of speakers...ect??? Also, when you say "20-20kHz"...what does that mean? How important are those numbers? What is better or worse?
As for the $4k for karaoke question? I work 6 days a week and on some weekends I have my friends come over to drink. Let me tell you.....it's nothing more hilarious than watching drunk guys trying to sing :). Well, soon we'll be watching NFL Sunday games so my hear will have some rest for a while.
Again, thanks for everyone input.
Pat D
08-25-2004, 07:38 PM
Thanks Jim and Pete. The connection you (Jim) described to me is exactly what I had in mind but I'm an electronic dummy so hearing from you is a plus. Do you have in mind a better combination of components that I could put together for a great karaoke system Jim? A pre-amp? Another amp? Another set of speakers...ect??? Also, when you say "20-20kHz"...what does that mean? How important are those numbers? What is better or worse?
As for the $4k for karaoke question? I work 6 days a week and on some weekends I have my friends come over to drink. Let me tell you.....it's nothing more hilarious than watching drunk guys trying to sing :). Well, soon we'll be watching NFL Sunday games so my hear will have some rest for a while.
Again, thanks for everyone input.
First of all, the top line Denon receivers I have seen reviewed have pretty formidable amplifier sections. I imagine yours does, too. I would not be sure that the separate amp, which is rated with slightly lower power, would be any better, even at low impedances.
The frequency range from 20 Hz to 20,000 Hz is traditionally taken to be the range of frequencies people can hear, and at the upper limits, usually only the very young can hear that high--especially with the advent of the Walkmans used by so many young people to damage their hearing.
I am not sure of the details, but in the US, if an amp is stated to produce so many watts into such and such an impedance over such and such a frequency range, it must be able to meet that spec. As well, the major manufacturers are liable to find their equipment measured by reviewers, so that they have another reason to not misrepresent their products.
Now, if they do a maximum undistorted power measurement at 1000 Hz, it will probably be somewhat higher than at 20 Hz or near 20 kHz. This means that a 20-20K spec is not directly comparable to a 1K spec. The 20-20kHz spec is more stringent. Not that there's likely to be more than a few watts difference, but if you want to advertise an amp, it looks much better to the general public to say it can produce 100 watts at 1 kHz than to say it can meet a 90 watt spec from 10-20K. Indeed, it could be the same amp.
It also looks more impressive if you say this amplifier is rated at 100 watts, whereas that one is rated at a full 125 watts. But really, in loudness terms this is pretty negligible. Remember that our perception of loudness is roughly logarithmic in the midrange. If you double the power output, this is a mere 3 dB change in loudness, which is somewhat noticeable. To sound twice as loud requires a change of about 10 dB, which is to times the power! Now, 1 watt is 0 dBW on the scale, 2 watts is 3 dBW, 10 watts is 10 dBW and 100 watts is 20 dBW. 125 watts is about 21 dBW. So in loudness terms, the difference in loudness between a 100 and a 125 watt amplifier is a barely noticeable 1 dB. I found a link to a dBW calculator.
http://www.bessernet.com/jobAids/dBmCalc/dBmCalc.html
Resident Loser
08-26-2004, 05:46 AM
...It just seems like "overkill" to my "cheapskate" mentality, hence my editorializing...but hey, whatever floats yer boat...
20Hz-20kHz is the "nominal" range of human hearing...lowest frequencies to the highest...not that many people have that wide a range. In electronics specs(particularly speakers) there is usually a tolerance specified "+/-" a level of dbs(decibels), or as PatD indicated, a specific freq, say 1kHz, at which measurements are made. Other factors are RMS(Root Mean Square) ratings, or Music Power, or IPP(Instantaneous Peak Power), into specific loudspeaker loads 4ohm or 8ohm...what you want to look for is something like "xxxWpc RMS/both channels driven, 20Hz-20Khz@ 8ohms"(or 4ohms if that is what your speakers are rated for)...anything else is probably an inflated specification...
Yeah, you can always go for separates and such, but your receiver was, at one point, top-of-the-line and, if I'm not mistaken, the amp is of a three-channel mono design(a good thing) and has THX cerification(which to some folks makes it a "better" class of product).
jimHJJ(...your stuff is probably quite sufficient for a nice Sunday afternoon songfest...and then some...)
HelpMeOut
08-26-2004, 04:57 PM
Thanks you guys for educating me on decibels, frequencies, RMS, ect....I've learned quite a bit here already. I guess I can put my system together now....but I have a couple more questions Jim. I have a Yamaha GE-30 equalizer. Should I use the equalizer or should I just leave it alone? Should I use a center channel (infinity, polk) for karaoke or just use my 2 main IL50's? What kind of cables should I use? I now use regular Monster RCA cables for my connections. Thanks for your valuable time Jim.
Resident Loser
08-27-2004, 07:26 AM
...I can find in their current product line for GE30 is a guitar case, I'll assume we're dealing with an older and obscure(information-wise) EQ unit...so again, some educated guesswork...possibly a one-third octave mono-unit or a stereo two-third octave one...if it's the former, a mono unit will have little use in a stereo situation(assuming of course we are dealing in a stereo situation). If the latter, and if you need to equalize, by all means use it.
That being said, here is the "however" part...Equalizers, if not adjusted properly and simply used as some sort of gain device, can do more harm than good...They really need to be used in moderation and set up with calibrated tone sources and measuring equipment to do a proper job...so perhaps you are better off without further complications, particularly since your application doesn't seem to involve critical listening.
Center channel? I think that's really a matter of personal preference(again, in light of your intended use)...you have the gear, use what you will...or won't, as the case may be...
Wires? Cables? Well, I am of the opinion that wire is pretty much wire...Reasonably priced RCA-type ICs that are well constructed and speaker wiring of an appropriate gauge for the length required, seem to exhibit little or no sonic difference to the oft-hyped pricier versions...there is great debate among hobbyists surrounding this issue. Suffice it to say, although there has yet to be any study or test that reveals any difference, there are two very polarized groups who hold fast to their opinions in this matter...Even the most ardent supporters will tell you, that the effects of this aftermarket wiring is subtle at best, requires SOTA(State Of The Art)gear and an experienced listener to realize any benefits from the greater expense involved...one more time, not necessarily a real consideration in your application, but ultimately, you're paying the check so it's up to you...
jimHJJ(...hope that helps...)
HelpMeOut
08-27-2004, 06:25 PM
Thanks For All Your Help Jim!!!
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