I know there are certain limitations about posting graphs on this forum, but I should explain that all my computers were bought with a view to photo processing. Room equalisation wasn't even on the radar when I bought them, so I have to make the best of what I have and throw in a large dollop of patience.
If anybody on here is running Mac iBooks and REW and can interface to the midi input on the BFD, I'd be well interested to hear fom you.
Some backgound. I've chosen not to do a house curve just yet, because 1) flat is tricky enough for me at the moment, because 2) I don't have REW or computer with the necessary soundcard and 3) because my head hurts. I also seem to have ended up with a 6dB lift down to 25Hz albeit by accident rather than design.
A house curve is on the cards and I'm looking into ways of doing it, but I'm a bit worried about broad filter boosting frequencies below 20Hz because the Monolith doesn't have a high pass filter to protect it, like the PB-10 for instance. I suppose I could do a broad boost and then apply a massive narrow cut centered on 16Hz, or I could follow Waynes advice with a broad, deep cut centered on 300 to 400Hz. But that's for next week.
In the mean time, SWMBO was off researching her family tree. Back to 1732 (that's before we even founded you :devil: )and they've moved as far as the next village up the road - they're very local:laugh: Therefore, I had some time to play.
The main problem I'm having with this very manual approach, is time. Adjusting a filter, running a sweep of test tones, typing the numbers into a spread sheet as you go, is slow. At least you see the graph change as it goes, so you know if you're in luck or you've cocked it up. But I'm limited to a 1/6th octave resolution and the troublesome frequencies aren't. AND each filter can have effects further up the frequency range, so you can't just sweep the bit you're trying to alter. No it's all 22, 10 second tones every time.
For instance, on the graph the peak at 36Hz. It's not, it's at 33.75Hz (according to the room mode calculator HERE). So I have to cross reference back and forth between the latest graph, room mode calculator, and ISO frequency charts.
Anyhoo, The yellow line is the Monolith with no BFD, the blue is last weeks effort and the red this weeks.
Peak @ 33.75Hz (Axial mode along the length of the room) is long gone,Peak @ 48.5Hz (Axial mode across the room) and the dip between '33.75Hz and 48.5Hz have been smoothed quite nicely. Dip @ 71.6Hz just disappeared while I was playing with the first two filters. I had being trying to target it previously with its own filter, but somethings working so I'll leave that well alone. The real sod is the peak around 100Hz. I think its because that it's a combined result of second and third harmonic resonances of the two main room modes all being near a lower order resonance of the axial modes. That and the fact the main speakers are dominant in output at this frequency. If I apply a big enough cut, no matter what the band width, to affect this peak it knackers things way down the scale. I can't EQ the mains except with Audessey MultEQ and I have no control over how it really works nor actually like the results of it being applied.
The short of it is, that I was mighty impressed with the Monolith after my MJ Ref 200. The thunderous nature of it's ablity to move the fabric of my house without effort was quite a revelation. But it's only now that I'm appreciating how deep it really goes. The major in room peaks I was suffering were all but masking lower volume, deeper sounds. I was feeling their energy, but now I'm hearing them as well. As I've tamed the peaks I've been turning the Monolith up. I've gone from 9 o'clock on the low level gain to about 10:30 but it doesn't sound louder, just much deeper and tighter. If you have a Monolith, you'll know that turning it up 1 1/2 notches equals quite a lot louder. I placed my hand on the door to the room at 22Hz to stop a rattle and was astonished to find I could feel it flexing under my hand - not buzzing but actually flexing with the pressure in the room.
If anybody has any suggestions based on this ****** graph, I'm more than happy to listen.
Now, where did I put U-571?
Russell
Edit: better graph attached. 02/06/07
Edit: Unfiltered response re-run -10dB. 03/06/07
If anybody on here is running Mac iBooks and REW and can interface to the midi input on the BFD, I'd be well interested to hear fom you.
Some backgound. I've chosen not to do a house curve just yet, because 1) flat is tricky enough for me at the moment, because 2) I don't have REW or computer with the necessary soundcard and 3) because my head hurts. I also seem to have ended up with a 6dB lift down to 25Hz albeit by accident rather than design.
A house curve is on the cards and I'm looking into ways of doing it, but I'm a bit worried about broad filter boosting frequencies below 20Hz because the Monolith doesn't have a high pass filter to protect it, like the PB-10 for instance. I suppose I could do a broad boost and then apply a massive narrow cut centered on 16Hz, or I could follow Waynes advice with a broad, deep cut centered on 300 to 400Hz. But that's for next week.
In the mean time, SWMBO was off researching her family tree. Back to 1732 (that's before we even founded you :devil: )and they've moved as far as the next village up the road - they're very local:laugh: Therefore, I had some time to play.
The main problem I'm having with this very manual approach, is time. Adjusting a filter, running a sweep of test tones, typing the numbers into a spread sheet as you go, is slow. At least you see the graph change as it goes, so you know if you're in luck or you've cocked it up. But I'm limited to a 1/6th octave resolution and the troublesome frequencies aren't. AND each filter can have effects further up the frequency range, so you can't just sweep the bit you're trying to alter. No it's all 22, 10 second tones every time.
For instance, on the graph the peak at 36Hz. It's not, it's at 33.75Hz (according to the room mode calculator HERE). So I have to cross reference back and forth between the latest graph, room mode calculator, and ISO frequency charts.
Anyhoo, The yellow line is the Monolith with no BFD, the blue is last weeks effort and the red this weeks.
Peak @ 33.75Hz (Axial mode along the length of the room) is long gone,Peak @ 48.5Hz (Axial mode across the room) and the dip between '33.75Hz and 48.5Hz have been smoothed quite nicely. Dip @ 71.6Hz just disappeared while I was playing with the first two filters. I had being trying to target it previously with its own filter, but somethings working so I'll leave that well alone. The real sod is the peak around 100Hz. I think its because that it's a combined result of second and third harmonic resonances of the two main room modes all being near a lower order resonance of the axial modes. That and the fact the main speakers are dominant in output at this frequency. If I apply a big enough cut, no matter what the band width, to affect this peak it knackers things way down the scale. I can't EQ the mains except with Audessey MultEQ and I have no control over how it really works nor actually like the results of it being applied.
The short of it is, that I was mighty impressed with the Monolith after my MJ Ref 200. The thunderous nature of it's ablity to move the fabric of my house without effort was quite a revelation. But it's only now that I'm appreciating how deep it really goes. The major in room peaks I was suffering were all but masking lower volume, deeper sounds. I was feeling their energy, but now I'm hearing them as well. As I've tamed the peaks I've been turning the Monolith up. I've gone from 9 o'clock on the low level gain to about 10:30 but it doesn't sound louder, just much deeper and tighter. If you have a Monolith, you'll know that turning it up 1 1/2 notches equals quite a lot louder. I placed my hand on the door to the room at 22Hz to stop a rattle and was astonished to find I could feel it flexing under my hand - not buzzing but actually flexing with the pressure in the room.
If anybody has any suggestions based on this ****** graph, I'm more than happy to listen.
Now, where did I put U-571?
Russell
Edit: better graph attached. 02/06/07
Edit: Unfiltered response re-run -10dB. 03/06/07