DanRA
Grip
- Joined
- Jul 4, 2000
- Messages
- 16
Hi All,
Below are Links to 3 graphs (I hope). I Tried to put the graphs below but if they don't show up you can use the links at the bottom.
First , I will describe my setup. I use a Lexicon DC-1 V4.0 for my Pre/Pro. I have Polk Signature SDS SRS 1.2 mains. These are very big full range mains. These are setup Bi-amped using a Mark Levinson 23.5 for the LF's and a Mark Levinson 29 for the tweets. The mains are setup on slides with custom locking clamps so I can position them in HS position or HT position in a few seconds. It is quite a feat because they weigh 185 #'s each and you can slide them back and forth with one hand. The mains also have heavily modified crossovers, new binding posts and all soldered connections inside. I am using a Behringer Ultracurve for the Mains but only the LF's. I looked at the FBD but the Ultracurve had slightly better specs. Using the Ultracurve on my mains I wanted as good as possible. My HS/HT is in the basement and has some nasty room mode that makes music with a fair amount of bass fatiguing and annoying. Most here use the FBD for their subs but my mains go very low and I like it that way. Don't try to tell me to cross them higher I have tried it and don't like it. The mid-bass punch and LF from the 1.2's will knock you off your chair. I use two Snell 550 subs with updated drivers that are driven by a Carver 35x THX amp. I have the Snells crossed at 40hz to help only with very LF's. All of this can be seen on my extensive web page links below.
I graphed my right main first with and W/O the subs and got a pretty good first pass correction I was happy to make such good progress (First graph labeled Right main). The Dark Blue curve shows the Right main & Right sub W/NO EQ. The Magenta curve shows the Right Main and Right sub with the peaks reduced @ about 67 & 94hz. It has a couple of dips that need some work but the peaks were smoothed out nicely and sounded much better than the peaks. I played with boost but didn't like the results. I will also note the anal side of me made me modify the excel worksheet I downloaded to add 1 hz increments and I also downloaded all the sine wave files (much thanks Sonnie and other contributors!!!).
I graphed my Left main W/my Left sub and had a big surprise. I had this huge dip from about 26-43Hz range I couldn't figure out (Second graph Dark Blue curve). If you look at the Dark blue curve it is also shows the peaks above about 50hz (NO EQ). I removed these peaks in all the other graphs using the Parametric filters so all the other graphs show much better results above about 50hz. It is simply amazing the improvement after eliminating the peaks at about 67 and 92hz. I would never go back and finally can listen to music with LF's. When I complete the LF issues I will fine tune a little more but it looks pretty good for now. This 26-43Hz section in the LF's was so big I thought something was wrong so I checked each driver. Well after playing for a while, I found out the sub on the Left side has almost no effect!!!! You can see this if you compare the Dark Blue curve vs the Red Curve, There is a pretty serious room effect in the Left corner. I turned on the right sub turned off the left sub and boom it looks much better, not perfect but much better (Second graph baby Blue curve). It shows very similar dips in all the curves and as the right channel @ about29 and 39 but raised the area about 10db over the left sub reading. The Magenta graph the left shows the left main and left sub with boost. The curve doesn't look so bad but it sounded like someone puked on a microphone (bad option). The Red graph shows the mains with no sub. Again the red graphs show the dips @ 30ish & 40ish that show in the right channel but that 26-43Hz area about 10 db lower.
Now I know I was on the right track but still didn't like the 2 dips @ 30ish & 40ish even though it sounds pretty good. I moved the Left sub around played with phase but it didn't help those two dips. Well I decided to try stacking the 2 subs in the right corner to see what would happen. I had heard this was a good thing to try so what the hell. The 3rd graph shows the original Dark Blue curve with No EQ and Left sub for comparison from the start. The Magenta curve shows the Left main & 2 Snell subs stacked in the Right corner of the room. This still didn't help the 2 dips @ 30ish & 40ish but the level is up considerably higher (near 85 db @ 10hz!). Now for my take on this and I am looking for comments suggestions and if people agree on what I am thinking. I am thinking I will leave the 2 subs stacked in the right corner but add a BFD to the SUB's and cut the 23 & 35hz peaks (see graph 3). I currently have no EQ on the subs. I figure this will effectively raise the 2 dips without any EQ boost. I figure I can attain a very good curve in the LF's and have zero boost. What do you think?????? The Magenta curve in the 3rd graph shows no boost at all, only cuts.
SIDE NOTE:
I don't think most of you would have picked up one this but my first readings used one sub for each channel measurement even though the sub output from the Prepro is single (not related to right and left). This means LF's routed to the sub would have been to both subs in actual use. I probably wouldn't have noticed this because the placement of that Left sub had almost no effect anyway but I figured I should note my original measurements were not done correctly using each sub with each channel. I realized this when I figured out what was happening with the room effect. Also, in hindsight it was a good mistake because if I had taken measurements with both subs on I might not have found the left room effect relating to the sub as quickly. In other words the left sub would not have been helping and I wouldn't have known it with out testing them separately. All future work will be done with both subs and checking individually to be sure. Interestingly the Right side of the room is cement foundation corner 10" thk. The Left corner is a studded side wall. I assume my different results with the two sides are due to the corner differences. Any Acoustical geniuses want to chime in here about if it is worth doing anything about this. I was thinking I could stiffen up the wall but not sure if it would be worth the effort because it is only very LF that seems to be effected.
GRAPH 1 - RIGHT MAIN WITH RIGHT SUB:
Link Removed
GRAPH 2 - LEFT MAIN 4 CURVES:
Link Removed
GRAPH 3 - LEFT MAIN USING 2 SUBS STACKED IN THE RIGHT CORNER:
Link Removed
LINKS TO GRAPHS & WEB PAGE LINKS INCLUDED ALSO:
GRAPH 1 - RIGHT MAIN WITH RIGHT SUB:
http://photos.yahoo.com/bc/dhummm/vw...iew=t&.hires=t
GRAPH 2 - LEFT MAIN 4 CURVES:
http://photos.yahoo.com/bc/dhummm/vw...iew=t&.hires=t
GRAPH 3 - LEFT MAIN USING 2 SUBS STACKED IN THE RIGHT CORNER:
http://photos.yahoo.com/bc/dhummm/vw...iew=t&.hires=t
HOME PAGE (7 pages of GEEKLAND):
http://www.geocities.com/dhummm/index.html
FRONT VIEW HT AND EQUIPMENT:
http://www.geocities.com/dhummm/page3.html
Sorry for the long post but the geeks will appreciate it (I think)
Ralph-
Below are Links to 3 graphs (I hope). I Tried to put the graphs below but if they don't show up you can use the links at the bottom.
First , I will describe my setup. I use a Lexicon DC-1 V4.0 for my Pre/Pro. I have Polk Signature SDS SRS 1.2 mains. These are very big full range mains. These are setup Bi-amped using a Mark Levinson 23.5 for the LF's and a Mark Levinson 29 for the tweets. The mains are setup on slides with custom locking clamps so I can position them in HS position or HT position in a few seconds. It is quite a feat because they weigh 185 #'s each and you can slide them back and forth with one hand. The mains also have heavily modified crossovers, new binding posts and all soldered connections inside. I am using a Behringer Ultracurve for the Mains but only the LF's. I looked at the FBD but the Ultracurve had slightly better specs. Using the Ultracurve on my mains I wanted as good as possible. My HS/HT is in the basement and has some nasty room mode that makes music with a fair amount of bass fatiguing and annoying. Most here use the FBD for their subs but my mains go very low and I like it that way. Don't try to tell me to cross them higher I have tried it and don't like it. The mid-bass punch and LF from the 1.2's will knock you off your chair. I use two Snell 550 subs with updated drivers that are driven by a Carver 35x THX amp. I have the Snells crossed at 40hz to help only with very LF's. All of this can be seen on my extensive web page links below.
I graphed my right main first with and W/O the subs and got a pretty good first pass correction I was happy to make such good progress (First graph labeled Right main). The Dark Blue curve shows the Right main & Right sub W/NO EQ. The Magenta curve shows the Right Main and Right sub with the peaks reduced @ about 67 & 94hz. It has a couple of dips that need some work but the peaks were smoothed out nicely and sounded much better than the peaks. I played with boost but didn't like the results. I will also note the anal side of me made me modify the excel worksheet I downloaded to add 1 hz increments and I also downloaded all the sine wave files (much thanks Sonnie and other contributors!!!).
I graphed my Left main W/my Left sub and had a big surprise. I had this huge dip from about 26-43Hz range I couldn't figure out (Second graph Dark Blue curve). If you look at the Dark blue curve it is also shows the peaks above about 50hz (NO EQ). I removed these peaks in all the other graphs using the Parametric filters so all the other graphs show much better results above about 50hz. It is simply amazing the improvement after eliminating the peaks at about 67 and 92hz. I would never go back and finally can listen to music with LF's. When I complete the LF issues I will fine tune a little more but it looks pretty good for now. This 26-43Hz section in the LF's was so big I thought something was wrong so I checked each driver. Well after playing for a while, I found out the sub on the Left side has almost no effect!!!! You can see this if you compare the Dark Blue curve vs the Red Curve, There is a pretty serious room effect in the Left corner. I turned on the right sub turned off the left sub and boom it looks much better, not perfect but much better (Second graph baby Blue curve). It shows very similar dips in all the curves and as the right channel @ about29 and 39 but raised the area about 10db over the left sub reading. The Magenta graph the left shows the left main and left sub with boost. The curve doesn't look so bad but it sounded like someone puked on a microphone (bad option). The Red graph shows the mains with no sub. Again the red graphs show the dips @ 30ish & 40ish that show in the right channel but that 26-43Hz area about 10 db lower.
Now I know I was on the right track but still didn't like the 2 dips @ 30ish & 40ish even though it sounds pretty good. I moved the Left sub around played with phase but it didn't help those two dips. Well I decided to try stacking the 2 subs in the right corner to see what would happen. I had heard this was a good thing to try so what the hell. The 3rd graph shows the original Dark Blue curve with No EQ and Left sub for comparison from the start. The Magenta curve shows the Left main & 2 Snell subs stacked in the Right corner of the room. This still didn't help the 2 dips @ 30ish & 40ish but the level is up considerably higher (near 85 db @ 10hz!). Now for my take on this and I am looking for comments suggestions and if people agree on what I am thinking. I am thinking I will leave the 2 subs stacked in the right corner but add a BFD to the SUB's and cut the 23 & 35hz peaks (see graph 3). I currently have no EQ on the subs. I figure this will effectively raise the 2 dips without any EQ boost. I figure I can attain a very good curve in the LF's and have zero boost. What do you think?????? The Magenta curve in the 3rd graph shows no boost at all, only cuts.
SIDE NOTE:
I don't think most of you would have picked up one this but my first readings used one sub for each channel measurement even though the sub output from the Prepro is single (not related to right and left). This means LF's routed to the sub would have been to both subs in actual use. I probably wouldn't have noticed this because the placement of that Left sub had almost no effect anyway but I figured I should note my original measurements were not done correctly using each sub with each channel. I realized this when I figured out what was happening with the room effect. Also, in hindsight it was a good mistake because if I had taken measurements with both subs on I might not have found the left room effect relating to the sub as quickly. In other words the left sub would not have been helping and I wouldn't have known it with out testing them separately. All future work will be done with both subs and checking individually to be sure. Interestingly the Right side of the room is cement foundation corner 10" thk. The Left corner is a studded side wall. I assume my different results with the two sides are due to the corner differences. Any Acoustical geniuses want to chime in here about if it is worth doing anything about this. I was thinking I could stiffen up the wall but not sure if it would be worth the effort because it is only very LF that seems to be effected.
GRAPH 1 - RIGHT MAIN WITH RIGHT SUB:
Link Removed
GRAPH 2 - LEFT MAIN 4 CURVES:
Link Removed
GRAPH 3 - LEFT MAIN USING 2 SUBS STACKED IN THE RIGHT CORNER:
Link Removed
LINKS TO GRAPHS & WEB PAGE LINKS INCLUDED ALSO:
GRAPH 1 - RIGHT MAIN WITH RIGHT SUB:
http://photos.yahoo.com/bc/dhummm/vw...iew=t&.hires=t
GRAPH 2 - LEFT MAIN 4 CURVES:
http://photos.yahoo.com/bc/dhummm/vw...iew=t&.hires=t
GRAPH 3 - LEFT MAIN USING 2 SUBS STACKED IN THE RIGHT CORNER:
http://photos.yahoo.com/bc/dhummm/vw...iew=t&.hires=t
HOME PAGE (7 pages of GEEKLAND):
http://www.geocities.com/dhummm/index.html
FRONT VIEW HT AND EQUIPMENT:
http://www.geocities.com/dhummm/page3.html
Sorry for the long post but the geeks will appreciate it (I think)
Ralph-