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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
willemj
1,036 posts
 
So your sub has L and R inputs. That simplifies it a bit. All you have to do is to run a cable from L out from the Focusrite to L in on the sub. Ditto with R. I am not sure about the plug that you linked to (call Focusrite for advice). See here for more information: https://www.presonus.com/learn/technical-articles/Balanced-Unbalanced
Try the Antimode whenever you feel like it - I think you will love it.
I would cross over rather lower, like 40 Hz for a start, but you can experiment.
The Yamaha AS801 will be a bit easier, but the sound should be virtually the same, with a bit less dynamic headroom in that large room.
Bi-amping is not worth it in your situation, and adds a lot of worries.
An Oppo probably only makes sense if you want to play discs and/or want to connect a TV screen.
Once you have this up and running, stop worrying about the electronics (they will be more than good enough, even with far better speakers). Your three weakest links will be the main speakers (start saving for something like the bigger Harbeths), the room modes generated by the sub (get an Antimode), and the higher frequency reflections because of the hard walls, glass windows etc. (get some curtains, carpets, or whatever).
lowoverdrive OP
169 posts
 
@willemj "I am not sure about the plug that you linked to (call Focusrite for advice)".

I think the info I need is in the manual. Here's what it says:

"LINE OUTPUTS 1 to 4 – four balanced analogue line outputs on 1⁄4” (6.35 mm) jack sockets; use TRS jacks for a balanced connection or TS jacks for unbalanced. The signals available at all these outputs may be defined in Scarlett MixControl."

I believe RCA is unbalanced by definition (thanks for the balanced/unbalanced article - I'm reading that now).

This leads me to believe that the 1/4 inch to RCA adapters should be mono (TS), which is the style I have.

I can't see how using TRS (stereo) 1/4 inch to RCA adapters with RCA cables would make sense. Is there something I am missing?

(Granted, it will take me some time to get through that whole article you linked. It's a great article, but I don't think I'll understand it prior to the Yamaha arriving on Tuesday. I'll be ready to get things connected and give it a listen!)

If there is more to the connections than what the Scarlett 6i6 manual says, what would I need to ask Focusrite?

Thanks


lowoverdrive OP
169 posts
 
I received the Yamaha P5000S power amp. I'm going to post two follow up messages about it.

First, in this one, I will confirm how I connected it.

It turns out that what I speculated would work, in my post of 7-Jan-2018 and based on help from @willemj , does indeed work -- with one caveat. The volume knob on the Focusrite Scarlett 6i6 only controls analog outputs 1 & 2, not 3 & 4. I have 3 & 4 going to the subwoofer, which has its own volume control. It works, but that's not the most convenient solution. The Scarlett may have software control options for changing this, but I didn't see them yet. There may be other workarounds. (However, at the moment, it is not hindering my listening enjoyment.)

To put all the connection info in one place, here's a recap of my earlier message with the final connections:

Here are the panels on the amp, Scarlett 6i6 and subwoofer.
https://imgur.com/a/6Eh06
https://imgur.com/a/lMkPa (better rear of sw)

The subwoofer only has line level inputs labeled R and L/LFE. I used R & L (with 2 shielded RCA cables) from analog outputs 3 & 4 on the Scarlett 6i6.

At the Scarlett I used 1/4 inch mono to RCA adapters similar to these:

https://www.monoprice.com/product?c_id=104&cp_id=10429&cs_id=1042906&p_id=7176&seq=1...

On the subwoofer I set the low-pass to 80 Hz.

1/4 inch TRS analog outputs 1 (L) and 2 (R) on the Scarlett went to inputs A and B on the Yamaha via 1/4 inch balanced TRS to XLR balanced cables.

The connections do work correctly. It was not hard to connect at all. I had an idea of what I was doing from earlier research, so when the amp arrived I had it connected in no time and I have been listening to music since then.


lowoverdrive OP
169 posts
 
Follow up #2 - how does it sound?

My system now consists of these components:

  • 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
  • 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 (as DAC) (https://us.focusrite.com/usb-audio-interfaces/scarlett-6i6)
  • kSubwoofer 1: Polk Audio PSW125 Subwoofer
  • Yamaha P5000S power amp <-- purchased on recommendations in this thread. Thanks!

(Small point - I used the Polk subwoofer instead of the Klipsch. I may swap them later, but for now the Klipsch is in my home theater room.)

This is the best music listening experience I have had in my life (so far). It sounds absolutely fantastic!

The Yamaha P5000S made a big difference. That amp has, to my ears, much better sound than the Sony STR-DN1080. No surprise there, of course. But it also significantly improves upon the Yamaha A-S801 integrated amp.

I realize I don’t have any experience listening to the high end gear most of you guys have listened to, but I immediately did not like the sound of my initial setup with the Sony receiver, as discussed here:
https://forum.audiogon.com/discussions/new-system-has-fatiguing-harsh-high-frequency-sounds-how-to-f...

However, those same speakers, with the Yamaha P5000S sound really good to me. At this moment, I don’t really have any complaints. In fact, I’m overjoyed.

I am still shopping for speakers in the $5000/pair price range. I have been reading a lot of reviews and thinking about distortion, clarity, detail, sound stage, etc. To my (somewhat inexperienced) ears, this setup with the Yamaha power amp and the Polk RTi A7 speakers, lets me experience a very satisfying level of all the things I have been reading about that come with the best speakers and the best components. With my current system, the sound stage is surprisingly expansive. The detail and clarity are amazing. The harshness in the higher frequencies is gone.

I am beyond happy with this amp (and the whole system).

HOWEVER, I have only been listening to it for a couple hours. I assume if I start listening even more critically and look for some music the speakers can’t handle well, I will find problems... maybe.

For now, this is such a huge improvement that I am happy to just enjoy it for a while.

Also, as I noted above, because I do not have a traditional DAC or pre-amp (or receiver), I am limited in my input controls. Fixing that will be next on my list. I am probably going to order the Teac NT-503 and install the Android app for HQPlayer. See thread here.

I have the option to use a software DAW with the Scarlett 6i6, but that will only be temporary.

I’m really surprised how much better the Yamaha P5000S sounds compared to the Yamaha A-S801. That’s the biggest surprise so far. The Sony receiver is fine for my home theater setup in my small room. But the Yamaha A-S801 integrated amp is probably going back.

The Yamaha P5000S power amp is a keeper. It absolutely blows me away. Wonderful sound, even with my current speakers. Big surprise. Now I like these speakers too.

In case anyone else considers this amp, it is a lot bigger and heavier than I expected. Because of its depth, it barely fits on my shelf. And it comes with rack-mount tabs on the front, so it’s not the most attractive component... but I can remove the rack-mount tabs. Anyway, I like it and the style / appearance is not a problem for me. I am much more concerned about having beautiful speakers. I’m very picky about how my speakers look. The amp can be put where its not very visible, if needed.



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