Onkyo TX-NR5007 with Polk RTi A9's?

JBHorne

Hello all,

I'm looking at upgrading my 9.2 system to include 2x A9's for the fronts and an A6 center.

Will my receiver support it? It's Onkyo’s flagship receiver, the TX-NR5007, so I'd expect a "good" 145w/ch – better than a cheap receiver rated at the same output. Is this true?

Many professional separates are only rated at 200w/ch anyways...not sure how the extra 55w make “so” much difference…

Also, this receiver has a toroidal transformer as well as a pair of 22,000 microfarad capacitors, unlike the less expensive TX-NR3007. Does this help things?

I know it sounds stupid, but I really don't have the room to add a separate amp right now as I'm limited on cabinet space with everything else!

Many receivers also list a w/ch rating, but many enthusiasts state that the receivers are not capable of driving ALL channels at max power. Is this still true with my high-end Onkyo with 0.05% THD?

Any input you guys can give on using the A9's with the TX-NR5007 would be great. If you absolutely feel an amp is necessary, please voice your opinions!

Thanks!
Justin

mystik610

JBHorne wrote: »

Hello all,

I'm looking at upgrading my 9.2 system to include 2x A9's for the fronts and an A6 center.

Will my receiver support it? It's Onkyo’s flagship receiver, the TX-NR5007, so I'd expect a "good" 145w/ch – better than a cheap receiver rated at the same output. Is this true?

Many professional separates are only rated at 200w/ch anyways...not sure how the extra 55w make “so” much difference…

Also, this receiver has a toroidal transformer as well as a pair of 22,000 microfarad capacitors, unlike the less expensive TX-NR3007. Does this help things?

I know it sounds stupid, but I really don't have the room to add a separate amp right now as I'm limited on cabinet space with everything else!

Many receivers also list a w/ch rating, but many enthusiasts state that the receivers are not capable of driving ALL channels at max power. Is this still true with my high-end Onkyo with 0.05% THD?

Any input you guys can give on using the A9's with the TX-NR5007 would be great. If you absolutely feel an amp is necessary, please voice your opinions!

Thanks!
Justin

145 W + 145 W (8 ohms, 20 Hz–20 kHz,
0.05%, 2 channels driven, FTC)

Straight from Onkyo's website.

Thats 145 WPC peak with 2 channels driven....so if you're running a 5, 6, 7 or 9 channel set-up, you won't be getting anywhere near 145WPC....probably more like 30WPC.

Most separates are rated based on RMS figures, with all channels driven.

My separate amp and my Onkyo 706 have the same power ratings on paper, but in real world performance, the separate amp is quite a bit more powerful.

JBHorne

To be exact, the website states:

Power Output

Front L/R
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)

Center
145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)

Surround L/R
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)

Surround Back L/R
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)

Front High/Wide
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)


Dynamic Power

400 W (3 ohms, 1 ch)
300 W (4 ohms, 1 ch)
180 W (8 ohms, 1 ch)

So what does this all mean? That this receiver really cannot do 145w on all 9 channels simultaneously? Is this what dynamic power refers to?

kuntasensei

JBHorne wrote: »

So what does this all mean? That this receiver really cannot do 145w on all 9 channels simultaneously? Is this what dynamic power refers to?

The 5007 may or may not be able to do 145w per channel with all channels driven. The good news is... the time when it would ever be asked to do that during any movie at typical levels is pretty much never, short of you having a very large room or extremely inefficient speakers (which Polks definitely aren't). The odds are reduced even greater if you're not running the channels full range, as the greatest load is deep bass and redirecting that to the subwoofer can free up a great deal of headroom on the amp section.

What Mystik's referring to as far as the 2-channel rating is that lower grade Onkyos with a single power supply for all channels historically don't tend to deliver when all channels are driven. They can't because they're drawing from a common store of available power. This is less true of their 3007 and 5007 models, which have 4 independent power supplies fed by a larger transformer to ensure that they can deliver fairly close to their rated power.

The dynamic power is the amount that it can cleanly deliver in a transient burst, and the ratings for each impedance are given since impedance changes as the speaker is driven harder, especially where bass is concerned. That's why ohm ratings for speakers are given as a nominal rating - they actually fluctuate as the driver moves away from the former.

Bottom line: Will separates sound better? If you find an amp that sounds good with the speaker, absolutely. But will the 5007 sound pretty damn good with the RTiA9s? More than likely. But it's home theater... You can ALWAYS find better if you look. I suggest you hook it up and see how it sounds to you, so you can decide for yourself if you think the RTiA9s need more power. I'm running a 1007 with older RTi70 mains, and I think you're gonna get a pretty decent sound out of your system without an amp.

kuntasensei

Point taken, but considering the RTiA9s have a lower -3dB point near 30Hz, they should really be crossed over to a sub near 50-60Hz in a home theater setting anyway, which limits the need for external amplification significantly. If you're going to run them full range, there's no question that you should use external amplification to make them perform their best.

The other side of it is: How big a room are you trying to fill, and what are your typical listening levels? Most people don't realize it, but on systems crossed over at the typical 80Hz setting in a mid-sized room with the average listening level, it's pretty rare that any channel other than the sub gets fed more than 60w. If you aren't trying to run your system at reference level, having external amplification is typically a matter of diminishing returns. Additionally, where you'll get the most advantage with external amps is with the far greater damping factor, meaning you'll get tighter controlled bass... but again, most people's ears aren't sensitive enough to hear any difference past a damping factor of around 50, so it may not make a lick of difference other than knowing you have more power.

That said, both xcapri and I are right, because there is no one right answer. You're just going to have to hook it up and see how it sounds to you, and if you think your mains need more power, you have options.

dorokusai

I run a TX-NR5007 and there is nothing I've found it won't run....regardless of specifications. I'm sure it can't handle everything and it's the ugly version of the overpriced Integra series.

JBHorne

I have two PSW505's as well as two buttkickers on a dedicated 1900w amp @ 2ohms. Bass is hardly my issue, lol.

With that said, I have the subs crossed at the THX recommended 80Hz. All 6 of my surrounds are Polk R20's, FYI.

I just felt it was time to upgrade the front sound stage's 3 speakers.

My room is huge as this is not a dedicated theater. It's a great room about 30'x20' with odd speaker placements. I did the best I could with what I had to work with, and I think the Audacity programming did a very good job. I used an SPL meter to balance everything out to 75db, but let Audacity adjust the frequency curves.

Thanks for all the input guys! I guess I should just try them out and see what I think. I'm very much a fan of tight, controlled bass that really makes a movie kick.

PS >> If I had to use a separate amp, I'm assuming I would only need a 2ch for the fronts? No reason to have the center and the surrounds on a separate amp? I guess the Emotiva XPA-2 or XPA-3 would work, if I could get a good deal on one...

cnh

As said above....you'll have no problem running that set at NORMAL volumes with the Onkyo alone...that unit does put out its rated power for the most part and you have 8 ohm speakers...but it is ALSO true that your Rti-A9s are one bad As(z) powerhungry speaker....and as you know if you run those FULL range...they would benefit from an external amp because its tough to produce voluminous bass without enough power....LOTS of power.

If you let you sub take care of that then you're probably good as you are. But you're not getting the full potential of those A9s in two channel listening.

cnh

JBHorne

Power Output
Front L/R
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)

Center
145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)

Surround L/R
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)

Surround Back L/R
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)

Front High/Wide
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)


Dynamic Power

400 W (3 ohms, 1 ch)
300 W (4 ohms, 1 ch)
180 W (8 ohms, 1 ch)

Power Supply AC 120 V, 60 Hz
Power Consumption 11.6A

Sorry guys but I have a few more questions regarding these specs.

First off, what is dynamic power?

Second, each speaker set lists "145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%, 2 channels driven, FTC)". Does this not mean that each set is separate?

Moreover, the total power consumption is rated at 11.6A. Mathamatically,

11.6A x 120V = 1392w

145w x 9 = 1305w.

Difference = 87w

Does it not seem reasonable then that all of the other electronics use the remaining 87w and that all channels could receive 145w each?

kuntasensei

I answered the dynamic power question earlier in the thread. As to whether each set is separate, no one but Onkyo could tell you. With 4 power supplies in the 5007, it's hard to decide how that would break down to 9 channels.

Rocco1

OP

I have a similar set up at home. When I initially purhcased my 9s I listened to them on a onk 907 which is very similarly powered to the 5007. I thought the 9s sounded great on that at medium listening levels. There is a big difference the higher you want to turn up the volume.

I ended up using a seperate amp and for the large invest you will make on the speakers, I believe its a no brainer with the 9s. When amplified properly the sound is just far better. There isnt even a question.

Search ebay or audiogon for a good used amp, it will be well worth it.

JBHorne

So what if I just let the receiver handle the center channel, but use 2x stereo amps to drive the A9's bi-amped? Would leaving the A6 with the receiver not be recommended?

My other option would be a 200 x 3 amp, but that would still only drive the A9's at 200W.

Two 200x2 amps would drive the woofers with 200W each, and 200W for the midrange/tweeters. I'm guessing mixing amps would be a bad idea (more watts on the bottom than the top)?

What amps did you guys go with for the A9's? I'm not seeing too many 3 channel amps on ebay, but there sure are a lot of stereo amps.

PS >> Sorry about the dynamic power question again. I was getting to the 16A rating.

Rocco1

JBHorne wrote: »

So what if I just let the receiver handle the center channel, but use 2x stereo amps to drive the A9's bi-amped? Would leaving the A6 with the receiver not be recommended?

My other option would be a 200 x 3 amp, but that would still only drive the A9's at 200W.

Two 200x2 amps would drive the woofers with 200W each, and 200W for the midrange/tweeters. I'm guessing mixing amps would be a bad idea (more watts on the bottom than the top)?

What amps did you guys go with for the A9's? I'm not seeing too many 3 channel amps on ebay, but there sure are a lot of stereo amps.

PS >> Sorry about the dynamic power question again. I was getting to the 16A rating.

No problem. That is what this is for.

Well for the 9s they can handle a ton of power. I personally have 2 Adcom GFA555se, one for each 9. Some may say is over kill but i use my system for both HT and Music. Now if you are mostly home theater. You can go with a nice 3 channel to run all the fronts. You definitly want the front sound stage to work together, because that is a large majority of your sound.

As far as 2 seperate USED amps. Thats a real gray area. If your working with USED amps you could be opening a hole box of worms. Unbalanced power, irregular ware and tear, and all kinds of stuff. I am really anal about that stuff. So I would never travel down that road.

I would say in your application look for a nice Adcom 5503 or Emo UPA3, they have a nice used 5503 on Audiogon right now. Power your 3 front speakers and call it a day. Your going to notice a huge difference in sound. I would leave your 5007 to run the rest.

Last the great thing about this hobby is there is always someone willing to buy your used stuff, so if you get to the point were your willing to start kicking out some serious money, you can always sell your old stuff and bring in some new stuff.

JBHorne

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