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amp (or receiver) recommendation for Polk Audio RTi A7 floorstanding speakers

I started off building a 7.1 home theater system. Based on advice received here, I changed my plans. I'm re-purposing some of my components to a dedicated music system in another room. I would like some advice on this music system. (I'm keeping the home theater system in the smaller room and using smaller speakers with it.)

I am looking for a music system that will give me smooth, sweet, soft, silky treble with instruments like the Indian sitar or sarangi. These instruments can be challenging. I hope the system also has clarity and detail and enough punch for alternative rock in a large room.

I have two possibilities for listening location. One room is 18 feet x 22 feet with a tile floor, floor to ceiling windows on back wall and 8 foot ceiling. The front wall has a book case.

The other possible room is about 25 feet x 40 feet with a vaulted ceiling (approx 16+ feet at center). Back wall is also mostly glass. Flooring will be wood soon, but for now it is carpet. Neither room has curtains (or any window treatments) over the windows.

My old room was 11.5 feet x 11.5 feet and these speakers were too much for that small space (along with a large TV).

Let's assume I can arrange either new room so that my listening position and the speaker placement closely conforms to the "golden ratio" (http://www.ecoustics.com/articles/stereo-speaker-placement-optimum-sound/).

Here are the components I already own and would like to use:

  • pair of Polk Audio RTi A7 floorstanding speakers (8 ohms) - Sensitivity (1 watt @ 1 meter): 89 dB. Recommended Amp Power Per Channel: 20 watts → 300 watts
  • pair of Polk Audio RTi A5 floorstanding speakers (8 ohms) - Sensitivity (1 watt @ 1 meter): 90 dB. Recommended Amp Power Per Channel: 20 watts → 250 watts
  • Klipsch RP-250C Center Channel Speaker (probably won't use)
  • Klipsch R-112SW Subwoofer 600 W, powered
  • LG UP875 4K BLU-RAY PLAYER (plays audio CDs) (features HDMI, USB, and optical digital audio output)
  • computer with Asus X99 Deluxe II motherboard featuring Crystal Sound 3 audio (https://www.asus.com/us/Motherboards/X99-DELUXE-II/) (features USB, HDMI or optical S/SPIF output)
  • Focusrite Scarlett 6i6 USB audio interface (if needed) (https://us.focusrite.com/usb-audio-interfaces/scarlett-6i6)

Music will be played from my computer or the LG UP875 disc player.

What I have in mind is a 2.1 system with TWO pairs of front speakers (4 speakers total). I tried a dual front speaker setup briefly and I liked it, although I understand it is unconventional. But I have the speakers and I would like to try using them all. (If that is a really bad idea, even in a larger room, I'll give up on it.)

Also, I am curious to try bi-amp'ing and the speakers support it. If I use dual front speakers and bi-amp them 8 powered channels are required.

In a smaller room, I would not need a subwoofer with these front speakers. I don't know how that will turn out in a larger room. I don't listen to bass boosted music. But I assume I'll need a subwoofer. I assume I will not use the center channel speaker at all. I can return it.

Here's what I anticipate I'll need:

  • something with an amplifier
  • something with a sub out for the subwoofer
  • something to connect everything together (and, I guess, let me choose between the disc player and computer as sources)

What I do *not* need from the new components:
  • analog input sources
  • streaming, WiFi or networking (other than what I do with the computer)
  • home theater features or video support
My budget is about $1000, although I have some flexibility. But I only have about $2300 invested in the other components (not counting the center speaker, which I won't use, or the computer which is multi-purpose). So it doesn't seem to make sense to spend a whole lot more.

I am new to audio and home theater. I'm just learning now and I want to gain some experience before I increase my budget too much. Later, if I purchase much more expensive speakers, I'll get a more expensive preamp / amp combo. In my (limited) understanding the heart of an audio system -- where the money should be spent -- is the speakers and the amp. But with my most expensive speakers (the A7's) being $600/pair, it seems unreasonable to spend more than $1000 on a preamp+amp / integrated amp / stereo receiver (whichever is recommended) for this setup. If my logic is wrong, I guess I could be talked into increasing the budget to $2000 or so.
lowoverdrive
lowoverdrive OP
169 posts
 
willemj - "Focusrite - Is that what I think it is?"

Yes, I think so... I already use the Focusrite Scarlett 6i6 with my computer and a set of powered speakers (Logitech Z623). Going from that to a power amp with unpowered speakers seems like it should work, right?

The Focusrite Scarlett does indeed have a volume control.

willemj - "All in all and for now I would not buy an extra DAC. I think you are done."

I will at least try this approach and see how it goes. I'm pretty excited about it. I like the idea of buying one new piece of equipment and seeing what existing equipment I can re-use to come up with something that works. I'll learn from this and then I'll have a better idea what I want to try next.

In summary this is the next step I'll be trying:

A room of about 20 feet x 30 feet with a vaulted ceiling (approx 16+ feet at center) and a lot of open space. (I had the measurements wrong earlier.)

The components list:


First question - the A7 speakers are recommended with up to 300 watts and the Yamaha P5000S puts out more than that. What precautions should I take? Is it as simple as not turning the volume up too high?

Second question - how is the subwoofer connected to the Yamaha P5000S?

Third question - any tips on the settings for the subwoofer?

Thanks




lowrider57's avatar
lowrider57
5,418 posts
 
During a typical listening session your amp will be putting out a very low wattage, maybe 10 wpc. With your large room, it would be higher, but never approaching 300 watts continuously.

The 300 watt spec is for the nominal amount. The speaker can take momentary peaks much higher than the rated 300 watts.
lowoverdrive OP
169 posts
 
Here are the panels on the amp, DAC and subwoofer.

https://imgur.com/a/6Eh06

Unfortunately, this sub does not provide speaker level (hi-level) inputs.

I read a few different articles about the connection options. Here are the 3 I thought were best:

http://kenrockwell.com/audio/how-to-connect-subwoofers.htm
https://www.cnet.com/how-to/how-to-hook-up-a-subwoofer-to-a-stereo-system/
https://www.upscaleaudio.com/pages/subwoofer-tips

However, I would appreciate some recommendations for the subwoofer connection specific to this equipment. Anyone want to help?

Also, in addition to the actual connections, I would appreciate any thoughts on the settings on the back of the Yamaha. I'm guessing 80 Hz with the size of my A7 front speakers. Do I set both channels the same and run both channels to my subwoofer? Without the subwoofer having speaker level inputs, I am a bit confused about the best approach.


willemj
1,036 posts
 
Look at the manual of the Focusrite. From what I can see it has multiple analogue outputs, so you should be able to connect both main speakers and subwoofer to the Focusrite. From what I can see the Focusrite has balanced analogue outputs with TRS Plugs. The Yamaha has both Neutrik and TRS inputs, so you should be fine with a TRS to TRS cable to connect Focusrite to Yamaha. This way you can use the high pass filter on the Yamaha to relieve the main speakers from the very lowest frequencies (the sub will deal with those). Set it at something like 40 Hz, or maybe a bit higher.
Consult Focusrite about how to connect the sub to the Focusrite. At the very least this needs a TRS to rca cable.
You may consider a DSpeaker Antimode 8033 room eq unit to equalize the subwoofer and tame room modes. See here: http://www.theabsolutesound.com/articles/dspeaker-anti-mode-8033-dsp-subwoofer-equalizer-tas-204/ I have been very pleased with mine. In your case the stereo model may be convenient because it takes L and R inputs and has mono outputs (ask the DSpeaker importer for which types of cables you need).
If the Focusrite somehow cannot output signals to both the power amp and the sub, you will have to connect at speaker level, using an attenuation cable from the power amp’s outputs to the sub. But it had better be able to handle the Yamaha’s big power.
Since the Focusrite does not have tone controls (unless hidden somewhere) and for as long as you are only using a computer as your source, install the free Equalizer Apo (plus Peace interface) software on your computer. This is an advanced software equalizer that you can use for basic tone control, but also for more detailed parametric equalization. In fact, if you use the REW software and a UMIK-1 calibrated microphone you can do subwoofer equalization with this as well. But REW is hard work. So to keep it simple, use the Antimode for sub eq and the Equalizer Apo (without REW) as basic tone control. Use the high pass filter on the Antimode to relieve the sub from havng to reproduce the very lowest frequencies (say, below 15 Hz). This is a large room for a modest sub, and lowest frequencies are the hardest work (they need much more energy).
lowoverdrive OP
169 posts
 
Equalizer Apo claims to be Windows-only, so that leaves me out. But I can try Pulse Audio Equalizer on the computer, if needed.

The cables (TRS or TRS-to-RCA, etc.) don't sound like a problem. But I am confused by something very basic. I thought the connection had to flow in this direction: computer -> Focusrite -> Yamaha -> Speakers, which implies the speakers have to be connected to the Yamaha.

You said, "you should be able to connect both main speakers and subwoofer to the Focusrite."

I can understand connecting the subwoofer before the amp because it has its own internal power amp.

But how would the speakers be powered when connected to the Focusrite without the power running through the Focusrite? If the amp power is run through the Focusrite, isn't that potentially harmful?

Is there a good article somewhere that covers this topic? The articles I have read so far would all indicate that the speakers need to be connected to the Yamaha, not the Focusrite. I'm sure I'm missing some basic understanding.

BTW, the subwoofer is powered and is rated at a claimed 600W. I do have a less powerful Polk subwoofer that has speaker-level connects.
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