New Here - Looking to Learn!

[beaminge36]

Hi All,

This is my first post on this forum. After my brother moved out of my house, wife and I agreed to turn the attic into the man cave. Primary goal was a listening spot as we can't find a good setup in the living or family rooms. I have an old Yamaha C85/M85 combo that needs help on the right channel and am trying to narrow down which Troels Gravesen DIY speakers to build (likely the Jenzen Seas ER).

In the mean time, I figured I can work in parallel to setup the room optimally and am using my basement stereo and some older Boston Acoustic A100's. Just picked up the UMIK-1 and REW and took some base measurements.

I haven't played much with positioning. I started with 0 toe and adjusted width till I got a clear centered voice from the seating position.

Can you all provide some feedback and help disect the waterfalls and point out anything obvious causing the imbalance in the bass region L to R?

TIA!

Nick

Attic Setup with Left & Right views (this is important later):

Below are the Frequency plots and Waterfalls:

 

[Sonnie]

Hi Nick and welcome to AV NIRVANA.

Your overall response for both speakers doesn't really look all that bad. You have some natural roll-off below 60Hz which is really not uncommon for the A100 speakers.

You have a challenging room to do any better there. Those speakers would probably give you better imaging and soundstage if you spread them out and got them a little closer, but you'll sacrifice even more low-end response. I suspect your best best is going to be to add a subwoofer.

 

[beaminge36]

Thanks Sonnie! I actually have a 10” sub that’s hooked up. I took some more measurements last night with the sub on and it improved the low end but the dips followed the same pattern so I’m guessing this is the room modes interacting?

My biggest issue right now is I don’t have a steady and coherent image. The voices for the most part snap together but they tend to shift a little at times. Instruments aren’t as focused. And the image sometimes moves with the song.

I played some more with toe in, tried super aggressive where they cross a couple feet in front of me. I also narrowed the distance between speakers. I shifted them closer to one side. I actually haven’t played with distance from the front wall. I suspect that can influence the room modes effects. The aggressive toe in made a more coherent image but it felt too compressed.

I started looking at some of the other graphs and measurements and there seems to be differences between left and right. I wonder if this is causing the shifting image and lack of spatial clarity.

Are there successful examples of managing an asymmetrical listening environment?

 

[Sonnie]

Your room is a real challenge for placement. Look at Cardas speaker placement guide, and maybe try tilting the speakers back a little, or maybe raise them up a foot or so to see if that helps. The problem with moving them is you may get more frequency imbalance between the speakers, which will affect imaging, but you could look at getting a miniDSP with PEQ and Dirac Live to smooth everything out.

 

[mollie]

Hi Nick,
You are probably right concerning the "non coherence" issue.
I see in the area in between 300 and 2000Hz that there is a continous change in output level (one goes up, the other down and visa versa) and fase, so the total output level in that area is not counted up as it should. (non constant fase between left and rightchannel)

I use two full range Manger speaker units (active) which shows the same (bad) behaviour.
The two units have moreless the same output level but shows difference fases.
I could improve this behaviour somewhat with the help of a mini-dsp SHD unit.

The soundstage is not stable and will shift all the time. F.i. voices will shift from left to right when frequencie(s) are changing, the stage will be more diffuse and showing less depth.
Do a trial with only one fixed position to measure/check the output level f.i. the left speaker and do measure also the right speaker afterwords at the very same position.
The speakers are okay if both speaker outputs laying exactly over each other.
In that case the room plays a roll.
If not, try to make them the same. (filter components a.s.o)

Hopefully this will help you to get things better in your case!!!
Cheers,
mollie