I've been listening to these in the rough (picture at bottom of the linked page) since I built them 3mo ago and am very happy with them.
I'm looking for some pointers on where I might improve on them before I build any final structures.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=79511&perpage=10&pagenumber=11
They have a pair of CSS FR125S per panel (11.75"x20") and a pair of Dayton RS225S-8's per bass cabinet (11.75"x21"). All 3/4" 11 ply birch plywood.
Using Edge I found that the main panels start to roll off at 255Hz. The lower FR125S has a 6Mh inductor in parallel for a 1st order roll off at 212Hz.
The bass cabinets are powered by Mission M2Sas 75w @ 4 ohms, -18db plate amps purchased thru MCM. I normally run them at about 5/8 power with the XO level set in the middle, probably 80Hz or so.
I've wired them as such: out of the receiver and into the high level inputs of the plate amps, out of the high level outputs (-6db @ 125Hz) up to the main panels where the FR's are in parallel, straight into the top FR125S but through a 6Mh inductor into bottom FR125S.
My main concerns are:
I didn't wire the lower FR125S correctly. (I did what I thought was a .5 wiring on it to help with baffle step.)
The value of the inductor for the lower FR125S is totally out of whack or that the slope should be of a higher order. (an earlier than recommended roll off of the bottom FR125S sounds smoother to me.)
I should have gone with large drivers in the bass cabs. (My ideas at the time were driven by price and Fs over x-max and Qts. I was looking at the Dayton RS225S-8, the Dayton RS270S-8 or Extremis 6.8's. I choose the RS225S-8's because they were the cheapest. Since I don't use active eq or amps with bass boost I figured there would be no issue with x-max of the bass cabs, and so far there hasn't been. Keeping the physical size of the bass cabs, I may be able to go with 10's in thier place)
I should have used plate amps with;
- a different slope- (I thought the -18db slopes of the M2Sas's were a good compromise. For 2 channel music only some advocate -12db, others -24db, so I split the difference)
- built in bass boost- (I read on other posts that bass boost can sometimes sound real weird so I opted on the side of caution. Maybe this is only really an issue with ported or sealed units instead of OB?)
I'm still on the fence as to whether or not I want to stay dipole or go stacked U-baffle for the bass cabs but I do know that thier physical size is about all my little rooms can handle.
Thank you,
Jim
I'm looking for some pointers on where I might improve on them before I build any final structures.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=79511&perpage=10&pagenumber=11
They have a pair of CSS FR125S per panel (11.75"x20") and a pair of Dayton RS225S-8's per bass cabinet (11.75"x21"). All 3/4" 11 ply birch plywood.
Using Edge I found that the main panels start to roll off at 255Hz. The lower FR125S has a 6Mh inductor in parallel for a 1st order roll off at 212Hz.
The bass cabinets are powered by Mission M2Sas 75w @ 4 ohms, -18db plate amps purchased thru MCM. I normally run them at about 5/8 power with the XO level set in the middle, probably 80Hz or so.
I've wired them as such: out of the receiver and into the high level inputs of the plate amps, out of the high level outputs (-6db @ 125Hz) up to the main panels where the FR's are in parallel, straight into the top FR125S but through a 6Mh inductor into bottom FR125S.
My main concerns are:
I didn't wire the lower FR125S correctly. (I did what I thought was a .5 wiring on it to help with baffle step.)
The value of the inductor for the lower FR125S is totally out of whack or that the slope should be of a higher order. (an earlier than recommended roll off of the bottom FR125S sounds smoother to me.)
I should have gone with large drivers in the bass cabs. (My ideas at the time were driven by price and Fs over x-max and Qts. I was looking at the Dayton RS225S-8, the Dayton RS270S-8 or Extremis 6.8's. I choose the RS225S-8's because they were the cheapest. Since I don't use active eq or amps with bass boost I figured there would be no issue with x-max of the bass cabs, and so far there hasn't been. Keeping the physical size of the bass cabs, I may be able to go with 10's in thier place)
I should have used plate amps with;
- a different slope- (I thought the -18db slopes of the M2Sas's were a good compromise. For 2 channel music only some advocate -12db, others -24db, so I split the difference)
- built in bass boost- (I read on other posts that bass boost can sometimes sound real weird so I opted on the side of caution. Maybe this is only really an issue with ported or sealed units instead of OB?)
I'm still on the fence as to whether or not I want to stay dipole or go stacked U-baffle for the bass cabs but I do know that thier physical size is about all my little rooms can handle.
Thank you,
Jim
Final structures? What's wrong with those? 
quote:
"I didn't wire the lower FR125S correctly. (I did what I thought was a .5 wiring on it to help with baffle step.)"
Sound fine to me.
I think we all wish we were there so we could have a listen. Even though you and I were using similar drivers, the differences in our configurations and rooms makes an opinion difficult.
Still not quite happy?
That's the spirit man!
quote:
"I didn't wire the lower FR125S correctly. (I did what I thought was a .5 wiring on it to help with baffle step.)"
Sound fine to me.
I think we all wish we were there so we could have a listen. Even though you and I were using similar drivers, the differences in our configurations and rooms makes an opinion difficult.
Still not quite happy?
That's the spirit man!
Thanks Cal,
You know me, I read this and that and then some more and wow, it can get overwhelming. So many options and ideas. I was just hoping I implimented more of the right ones than the wrong ones!
Good to know on the .5 for the lower FR125S. As I think I told you before, the correct inductor value is nearer 4.48 but I thought it sounded too bright somewhere in the midrange.
I was also looking at the RS270-8's as a possible replacement for the 225's. The specs show them to be slightly more efficient plus the extra size might help.
-Side note: I finally plugged those CTS 15" drivers into my NoBoxys. I've been listening to them out in the garage for the past couple of hours using one of those M2Sas plate amps. What a whoomp! They must have a real high Qts. The combination of the CTS 12's running free down low and those 15's cut at 60-70Hz or so makes for heavy music if need be. Funny thing though is when you step out of the garage you can barely hear any bass.
R,
Jim
You know me, I read this and that and then some more and wow, it can get overwhelming. So many options and ideas. I was just hoping I implimented more of the right ones than the wrong ones!
Good to know on the .5 for the lower FR125S. As I think I told you before, the correct inductor value is nearer 4.48 but I thought it sounded too bright somewhere in the midrange.
I was also looking at the RS270-8's as a possible replacement for the 225's. The specs show them to be slightly more efficient plus the extra size might help.
-Side note: I finally plugged those CTS 15" drivers into my NoBoxys. I've been listening to them out in the garage for the past couple of hours using one of those M2Sas plate amps. What a whoomp! They must have a real high Qts. The combination of the CTS 12's running free down low and those 15's cut at 60-70Hz or so makes for heavy music if need be. Funny thing though is when you step out of the garage you can barely hear any bass.
R,
Jim
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