Humps at 43Hz, 90Hz, and 110Hz

[cjf]

@TheComputerAudiophile (Chris)

 

I'm curious if you happen to also have a good SPL meter on hand by chance? When I was recently setting up my new room/speakers/subs I spent quite a bit of time on the physical placement of the speakers/listening chair with the help of my SPL meter. I had a 25db difference in output between the Right/Left Main channels I was fighting with at certain Freq's. It was super obvious when sitting in the listening chair too. The Right channel would simply overpower and take precedence of the soudstage and I was losing faith.

 

Then I ended up playing Tones via REW at the worst Freq's at close to my REF Level. I would then start to crawl around on the floor near the problem speaker with SPL meter in hand. At one point, only a few inches away from the current location of that channel I found a Lull that was about -7db lower in level. I moved the speaker in that spot and "Re-Aimed" it at the listening chair. I then moved to the listening position and did the same thing near ear height with SPL meter in hand. Again about 2inches to the Left of the current chair position I found another LULL that returned an additional reduction of -3db. So after all was said and done I reduced my channel imbalance by -10db just by a few small corrections in physical location.

 

Now this isn't to say the same thing will happen in your case but I suspect it may return some decent results especially if you notice that its one channel being the biggest culprit in causing the Spike. All in one measurements are great to see the final result of all speakers working together but these types of measurements also tend to Mask/Hide what each individual channel is doing to contribute to the All channels measurement. Especially when out of phase signals come in contact with each other mid air

 

Another benefit in getting as much as you can from physical corrections first is that it reduces the amount of work the software correction filters will need to do; if you decide to use them of course. IME, this results is less loss of your volume headroom and reduces the amount of Gain you need to have in reserve from your chosen Pre/Dac that is driving your Amps.

 

One thing I found out pretty quick was that you run out of Vol output real quick once room correction is used (Plan for a solid -20db being chopped off your output level and that number goes up from there if the software has to do a lot of the hard work to correct things you could have dealt with in the physical world by moving speakers/chairs a few inches..etc). In my case I was lucky to have two DAC's capable of studio level output voltages to drive my Amps which gave me some of my Vol output back that I lost due to room correction.

 

Hope this is useful and good luck getting things setup. Its fun stuff either way