High level input and monolithic poweramp

Akeel Shah · 5 Oct 2020 at 17:06

So I have a Denon Poa t2 monolithic poweramp meaning the left and right channels have their own amplifier circuits. it has channel a and b selection and a powerbutton thats all on the front and on the back the speaker terminals and an Rca for each side... I used to run 2, 10 inch subs with my old avr which blew thus the need for my poweramp and also i hate home theatre filtering id rather have a raw signal and in the future a dac ... but as i have been researching if i was to get a high level input cable and subwoofer the connection is made from the positives of my channel b and ground. other end into the subwoofer im looking at the Rel r9i or something like thst with high level input my question is will it cause any issues because the power amp has two amplifiers internally one per channel. I really want to get the Rel sub it looks like exactly what i want but i also wouldn't want to blow my Denon Poa t2 its my first poweramp and im loving it so far just miss the love of sub bass . thanks for reading thru.

lucid · 6 Oct 2020 at 04:13

Your post doesn't really make complete sense, so I'm going to take a few guesses at what you mean by some of the things you've written. If I have misunderstood what you meant then please feel free to correct the details and add more information.

Your 2x 10" subs (running from the denon power amp or the AV receiver - Were they passive? The Rel T9i sub you're looking at is different. It has its own built-in amplifier.

The high level connection uses speaker wire and connects to the speaker terminals on an amplifier, but it doesn't draw any power from the amp. Instead, it works like a high-level to low-level conversion. The T9i high-level input is very high impedance (tens of thousands of Ohms), and so the power amp doesn't see this as a speaker load.

The high level cable has three wires. One is for ground. This connects to either of the black terminals on a stereo amplifier. The other two wires are used to connect to the two red terminals. This sums the left and right channel signals together. These connections are made at the same time with the speaker wires.

Akeel Shah · 6 Oct 2020 at 09:59

na the subs i used to have i had a separate monoblock car amp and i had it plugged into my old av via the subwoofer out.. since that died i bought a poweramp for my mains so left and right speaker is in channel a left and right terminals... i have channel b left and right free so i was hoping to get a rel subwoofer and do speaker level connections so use the power amps free left and right (channel b) and inputs for the high level out on the rel .. my consern now is if there would be that hum sound since the power amp is monolithic so has two amplifiers inside. so i may have to buy 2 subs from rel and have one for the left channel b and the second sub right channel b

Akeel Shah · 6 Oct 2020 at 10:01

the subwoofers were car subs so passive but powered by the pioneer 9601 so about 1200rms true power but as i want to use rels now that setup doesn't matter but it worked well

lucid · 6 Oct 2020 at 14:31

*** Don't use Spkrs B output on the Denon power amp. ***

Although the REL won't draw any power from the amp, by engaging Speakers B it will change the connections inside the amp so that it expects a 8-16 Ohm load as you would have with four speakers being driven.

*** You won't have four speakers being driven; just two. ***

The impedance of all speakers varies with frequency. There's also the phase reaction which affects power transfer. By engaging Spkrs A+B without a second set of 8 Ohm speakers connected you'll be hobbling the amp's abilities. Don't do it. Theres no reason to use Spkrs A+B with the REL or any sub with the same kind of high impedance high-level input.

The internal monoblock construction of the Denon amp is so that the left and right channels don't influence each other, or at least have minimal interaction. It's not a mono and for Spkrs A and a mono amp for Spkrs B, if that's what you're thinking.

Leave the Denon on Speakers A. Make the parallel connection with the high-level cable as I described above. If there's no hum through your main speakers now then there shouldn't be any hum from the REL either so long as you've not done something dum such as put the sub cable alongside a mains extension lead.

Car audio gear doesn't need to be made to the same tolerances as higher-end home audio gear. Some hiss and hum is acceptable in car audio products because the noise while driving or idling the engine will cover it.

I would take any power claims from car audio gear with a pinch of salt too. The same goes for mainstream audio and A.V. gear power claims. They're largely a work of fiction as well.

Akeel Shah · 6 Oct 2020 at 15:10

i also thought it would be abit risky so i ordered a emotiva pt100 preamplifier which has a standard subwoofer out...
it also has lots of digital inputs nice for pc or any device really also when i used to use my car subwoofer amp it barely created much heat (class D) and sounded great hum was a hit or miss depending on sockets etc however i fixed the issue by grounding the RCAs with this there was zero hum and the preamplifier allows for me to later down the line buy a rel subwoofer and connect to the low level input via rca perfect im so excited

lucid · 6 Oct 2020 at 16:08

Akeel Shah said:
i also thought it would be abit risky so i ordered a emotiva pt100 preamplifier which...

...which you conveniently forgot to mention.

So all this about the Denon and the REL and high-level connections was just a complete waste of the forum's time then.

That's a bit of a dick move, don't you think?

Akeel Shah · 6 Oct 2020 at 16:27

i ordered it just before the reply and obviously i wanted to do high level but i wont now with the knowledge provided so forum is useful