Can anyone offer some help interpreting these results from REW? I need to decide the best way to move forwards..

[marticus]

Hi guys, recently I purchased a cheap measurement mic, and following some guides have made a first attempt at taking some measurements in REW.

I calibrated the mic and levels prior to this and mic was at the MLP, I haven't got into measuring from multiple seats yet, this is just my first attempt.

For context, the sub is a Magnat monitor supreme 303a, which is an $150 12" subwoofer with 100w RMS, so there won't be any miracles happening with this sub, also this is a mixed use room that opens into kitchen, hallway, staircase etc. Walls are all concrete/brick with large windows throughout. So in short the worst possible scenario for good audio right?

I took several measurements with the Subwoofer in different positions within the reach of the cable, so nothing toward the back of the room, First two are in the front corners, next are out from the wall by about a 1.5 meters each side, and last is midway into the room on the right hand side.

The area i'm wondering about is the dip around 30hz, all the other areas, changed with positioning and look like they could be improved with a second sub, but that dip at 30hz, was consistent regardless of position. So do you recon that this is simply the limitation of the subwoofer? or some other room mode that I need to experiment further with?

I suppose I should take the sub outside and measure it independantly, but it will be a lot of work to drag all my gear out to the field ;-).

my goal here is to decide whether to spend a little bit on a second sub like this and resolve some of these issues for now before upgrading later, or save now and invest in something better in a while and then get a second later.

 

[Pogre]

Do you have any sweeps of both your main speakers and subs together? That dip at 30 hz is likely a room mode, but it's also fairly narrow and likely won't look as bad with a little smoothing applied to your graph. It does look like you could benefit from a 2nd sub and little eq or room correction tho. Your receiver is kinda limited as far as that goes. Do you also happen to have a MiniDSP 2x4 HD?

*Edit: it does appear you did apply 1/12 smoothing?

 

[marticus]

Do you have any sweeps of both your main speakers and subs together? That dip at 30 hz is likely a room mode, but it's also fairly narrow and likely won't look as bad with a little smoothing applied to your graph. It does look like you could benefit from a 2nd sub and little eq or room correction tho. Your receiver is kinda limited as far as that goes. Do you also happen to have a MiniDSP 2x4 HD?

*Edit: it does appear you did apply 1/12 smoothing?

Yep all those are with 1/12 smoothing already. Unfortunately I don't have sweeps of mains yet, that's the next step, just need to find time without the kids at home..

A minidsp is on the list for when I get a second sub, but I don't have one right now. It will be needed as you say the denon x1600h has dual sub outs but they're not independant, so it won't do much for equalisation.

Im moving the sub to the left (second graph down) as that seems the best for now, and deals with the null at 60hz, and I will remeasure with the mains.

The dropout at 30hz is frustrating, as wherever I position the sub (so far) it persists, do you think a second sub with phase alignment might iron that out?

I know that power alone won't fix that.

 

[Pogre]

Yep all those are with 1/12 smoothing already. Unfortunately I don't have sweeps of mains yet, that's the next step, just need to find time without the kids at home..

A minidsp is on the list for when I get a second sub, but I don't have one right now. It will be needed as you say the denon x1600h has dual sub outs but they're not independant, so it won't do much for equalisation.

Im moving the sub to the left (second graph down) as that seems the best for now, and deals with the null at 60hz, and I will remeasure with the mains.

The dropout at 30hz is frustrating, as wherever I position the sub (so far) it persists, do you think a second sub with phase alignment might iron that out?

I know that power alone won't fix that.

Honestly it's hard to tell until you dig in and do it. Nulls due to room modes are notoriously hard to deal with and you may not be able to eliminate it, but I think with some persistence, a second sub and educated eq'ing I'm pretty confident you can still make some real improvements. Not gonna lie tho, you could definitely do better for subwoofage. It looks like the one you have is struggling with true sub frequencies.

 

[marticus]

Honestly it's hard to tell until you dig in and do it. Nulls due to room modes are notoriously hard to deal with and you may not be able to eliminate it, but I think with some persistence, a second sub and educated eq'ing I'm pretty confident you can still make some real improvements. Not gonna lie tho, you could definitely do better for subwoofage. It looks like the one you have is struggling with true sub frequencies.

Thanks for the advise, I'm with you about the upgrade I think I'll keep hold of the $150 I would spend on a second one of the subs I have, and put it towards something better later!

Doing these measurements has been a good start, at least I know what I'm dealing with now!

I'll remeasure with the mains as you suggest and see how that's looking.

I'll see about some treatments in that cubby I have everything in too.

 

[Pogre]

Thanks for the advise, I'm with you about the upgrade I think I'll keep hold of the $150 I would spend on a second one of the subs I have, and put it towards something better later!

Doing these measurements has been a good start, at least I know what I'm dealing with now!

I'll remeasure with the mains as you suggest and see how that's looking.

I'll see about some treatments in that cubby I have everything in too.

I think saving for something better is a better plan if you can swing it.

Yes, absolutely having mic and the ability to measure your fr is invaluable if you really want to get serious and dial things in. I don't regret the purchase at all!

You'll be playing back with your mains and subs together so it's good to see what's going on with the big picture. It's possible it might look better with your mains in play, and you can experiment with different crossovers to see what works best. I'd start with 80 hz tho.

I'm not sure how much good it would do to treat the cubby. Rearranging would be, by far, the better solution. Trying to treat the cubby might just end in frustration, but room treatments aren't my best area of knowledge so don't just take my word for it and look into it a li'l further. I wouldn't commit to anything without consulting someone who can look at your room measurements and advise you on what to do.

 

[marticus]

I think saving for something better is a better plan if you can swing it.

Yes, absolutely having mic and the ability to measure your fr is invaluable if you really want to get serious and dial things in. I don't regret the purchase at all!

You'll be playing back with your mains and subs together so it's good to see what's going on with the big picture. It's possible it might look better with your mains in play, and you can experiment with different crossovers to see what works best. I'd start with 80 hz tho.

I'm not sure how much good it would do to treat the cubby. Rearranging would be, by far, the better solution. Trying to treat the cubby might just end in frustration, but room treatments aren't my best area of knowledge so don't just take my word for it and look into it a li'l further. I wouldn't commit to anything without consulting someone who can look at your room measurements and advise you on what to do.

Understood, and thanks again.

I know that treatments aren't going to help much in deep bass without some serious additions to the room, but I'm now thinking that I might be able to get the subs out of there and somewhere else leaving only the center, which might benefit from the help.

Regardless. first thing first, its clear I need to do some more measurements to get a better idea of what's going on.

 

[Pogre]

Done right, room treatments can make a huge difference. From what I've been reading up on tho, there are far more ways to mess it up than there are to improve things. You really have to be armed with as much knowledge as possible to determine what might help. I've seen a lot of stories where guys just start slapping up panels and bass traps all over the place, more or less blind and turn their room into an anechoic chamber, which isn't good. I'd definitely do the homework, take all the right measurements and consult an acoustician before doing any room treatments.

 

[marticus]

Done right, room treatments can make a huge difference. From what I've been reading up on tho, there are far more ways to mess it up than there are to improve things. You really have to be armed with as much knowledge as possible to determine what might help. I've seen a lot of stories where guys just start slapping up panels and bass traps all over the place, more or less blind and turn their room into an anechoic chamber, which isn't good. I'd definitely do the homework, take all the right measurements and consult an acoustician before doing any room treatments.

I got you, for sure I won't just start throwing foam and insulation up without checking first and at least now that I can measure I'm able to verify what changes are doing!

You're a big help, I appreciate all the time you spent giving me feedback.