Integrated amp issues

Doodsmack

I have an Onkyo A-9050 (https://www.amazon.com/Onkyo-9050-Integrated-Stereo-Amplifier/dp/B009JBZFVK). Ever since I set up my Epos Epic 2s it didn't seem right, like the speakers were just not being brought to life fully. Recently I redid the wiring, change impedance setting to 4 ohm, put sand in my stands, and turned on "phase matching bass". The last thing in particular seemed to bring the speakers to life, the bass exploded and everything sounded more vibrant.

Come to find out I had connected the speakers backwards. Switched the wiring for L and R. Now, phase matching bass doesn't have the same effect. It just ups the bass a little bit, but doesn't have the same transformative effect, and the bass is not as loud as before. I then switched to bi-wiring, which did not help.

Everything was perfect before except for L and R being backwards. Would that have caused the "phase matching bass" mode to behave in a different way??? This makes no sense.

F1nut

I don't know what the phase matching bass does, but yeah having your speakers wired out of phase is going to sound different than having them in phase. I suggest you live with it the right way as it will start to sound "right" in short order. Also, don't expect that integrated to have enough grunt to provide much bass slam. That takes a big power supply.

Nightfall

Do you mean you had + and - backwards or left and right channels backwards? It seems like you're saying that you connected left channel to right speaker and right channel to left speaker, in which case that should have made no difference to the bass, only the sound stage.

Msabot1

Having your speakers wired in phase will definately make a huge difference in sound quality...also good to remember there is no substitute for having enough head room to deliver un clipped signal...

Doodsmack

It was L and R I had backwards, not + and -, which is why this doesn't make sense to me. Also what do you mean by having head room?

Msabot1

You have nominal listening volume...having enough head room will ensure when you hit peak signal,you won't 'clip' the high off the wave...Another way too look at it is power reserve so you don't put your output signal into saturation....

Doodsmack

Tried putting L and R back to being backwards, but can't get the same effect back from phase matching bass. It really helped everything, not just the bass, the speakers sounded like they really should, voices sounded like they were in the room, etc. Now it's gone.

Just a garbage $500 amp I guess.

Msabot1

Not familiar with your amp...what is the RMS rating per channel?..

Doodsmack

So you're saying head room as in the power output of the amp? I am not entirely sure if this is the RMS rating but this is from the specs:

75 Watts per Channel at 4 Ohms, 1 kHz, 0.08%, 2 Channels Driven, FTC

Msabot1

Head room refers to the power reserve you have to avoid a clipped signal...I believe Onkyo rates their gear conservatively though..depends a lot on the impedance and efficiency of the speakers you are driving also...

Msabot1

That matching should be ok for moderate listening levels..Don't expect it to punch out sound pressure levels like a 150-200w amp will though...keep it moderate..

Doodsmack

Cool thanks. What is it that provides power reserve?

I keep the dial around 9:00, little higher to go big and little lower to be quiet in my room.