I'd say the limiter is set to the voltage, the wattage is going to depend on the impedance of the driver at whatever frequency.
I might be wrong, I should probably have another cup of coffee while I cuss under my breath about how s***ty the dimensions of this room are.
Nice to see data on the subs, sucks that room has such am impact on response but physics is physics. Nice to see in room below 20 Hz performance. I guess I will set my HPF accordingly.
I will have a minimum of three subs in my HT room, two of these design (will try the latest one that Oliver developed to be different) and a TTWQT using the Mal-X driver. Will probably add another pair of this design using TC Sounds drivers that DrDyna is using.
I will have a minimum of three subs in my HT room, two of these design (will try the latest one that Oliver developed to be different) and a TTWQT using the Mal-X driver. Will probably add another pair of this design using TC Sounds drivers that DrDyna is using.
Something tells me if you order two and do the swap, you'll probably order two more
Now that I'm thinking of it, at that cost, I wonder how the LMS-R 12 would model in this enclosure?
I'll have to mess with it later.
@ DrDyna
Jeepers what a nightmare
Anyway, good f3 you've achieved
Correct
Yeah, all the levels were the same, the distance only varied by moving the listening position between the two arrangements.
I'm thinking using the long wall will end up being less of an EQ problem in the long run, as un-optimal as that arrangement is for everything else...I've heard people say a few times that arranging speakers on the short wall of a rectangle room firing long-way is the best way to do it, but the dimensions of this room just make that problematic.
The only way I can do it is how I had it set up before, with the main speakers at the front and the subs at the back a couple of feet from the couch, but with them so close to the seating position, it's totally obvious that the bass is coming from back there, which wrecks everything else.
Edit: Yeah, the F3 is nice in any arrangement. About the same as it was with the big tapped horns, which is groovy.
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@ DrDyna
Yes, peaks can occasionally be quite impressive. Is your room about 6.37m long?
If this is the case, you get standing waves at 27Hz, 54Hz, 81Hz, etc, which match well the peaks of the "short-firing-long" graph on post #219.
These are boosted by the right on the front wall sub placement. Try placing the subs on the two long walls, but right in the middle of their length. This should greatly attenuate the 27Hz peak (and possibly create other sorts of problems ).
What puzzles me though, is the deep 40Hz null. With subs and seat on opposite walls, you shouldn't have deep nulls. Where was the mic placed? The main speakers? Or is the seat 2.15m off the back wall?
By the way, Zero D's suggestion of applying the correct amount of digital delay with the sub(s) as close to you as possible is a good idea:
Direct bass sound will be far stronger than the reflected one, plus you will play the subs at far lower levels exciting the room far less.
The downside is this restricts the correct listening position only to your sofa, you will have profound bass peaks and cancellations in different places of the room, and any port noises or sound besides bass WILL betray the sub's position.
One last thing: Contrary to popular belief, long-firing-short placement could be advantageous in a biggish (wide enough) room, particularly with twin subs. These, combined with the main speakers destroy the long-dimension standing wave, exciting lots of different sets of room modes.
Yes, peaks can occasionally be quite impressive. Is your room about 6.37m long?
If this is the case, you get standing waves at 27Hz, 54Hz, 81Hz, etc, which match well the peaks of the "short-firing-long" graph on post #219.
These are boosted by the right on the front wall sub placement. Try placing the subs on the two long walls, but right in the middle of their length. This should greatly attenuate the 27Hz peak (and possibly create other sorts of problems
).What puzzles me though, is the deep 40Hz null. With subs and seat on opposite walls, you shouldn't have deep nulls. Where was the mic placed? The main speakers? Or is the seat 2.15m off the back wall?
By the way, Zero D's suggestion of applying the correct amount of digital delay with the sub(s) as close to you as possible is a good idea:
Direct bass sound will be far stronger than the reflected one, plus you will play the subs at far lower levels exciting the room far less.
The downside is this restricts the correct listening position only to your sofa, you will have profound bass peaks and cancellations in different places of the room, and any port noises or sound besides bass WILL betray the sub's position.
One last thing: Contrary to popular belief, long-firing-short placement could be advantageous in a biggish (wide enough) room, particularly with twin subs. These, combined with the main speakers destroy the long-dimension standing wave, exciting lots of different sets of room modes.
Dimensions and Cutsheet - Baltic Birch
Attached are my first stab at filling in all the material dimensions and a cutsheet for the design posted by Oliver. I plan to use Baltic birch 13-ply material (60" x 60" x 0.75") that I will buy from a local wood supplier in Maryland. I only have MS Paint and PowerPoint so my level of accuracy is not that of tb46 who has more powerful tools, but MAY be good enough. Due to the precision of Oliver's numbers, I will have to do some rounding when actually start to cut wood. There is a typo in the dimension sheet, should be 16.987 for sides instead of 15.987.
I finally received my orders, so will be headed back to the US in August...
Attached are my first stab at filling in all the material dimensions and a cutsheet for the design posted by Oliver. I plan to use Baltic birch 13-ply material (60" x 60" x 0.75") that I will buy from a local wood supplier in Maryland. I only have MS Paint and PowerPoint so my level of accuracy is not that of tb46 who has more powerful tools, but MAY be good enough. Due to the precision of Oliver's numbers, I will have to do some rounding when actually start to cut wood. There is a typo in the dimension sheet, should be 16.987 for sides instead of 15.987.
I finally received my orders, so will be headed back to the US in August...
Attachments
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@ DrDyna
Yes, peaks can occasionally be quite impressive. Is your room about 6.37m long?
If this is the case, you get standing waves at 27Hz, 54Hz, 81Hz, etc, which match well the peaks of the "short-firing-long" graph on post #219.
These are boosted by the right on the front wall sub placement. Try placing the subs on the two long walls, but right in the middle of their length. This should greatly attenuate the 27Hz peak (and possibly create other sorts of problems
What puzzles me though, is the deep 40Hz null. With subs and seat on opposite walls, you shouldn't have deep nulls. Where was the mic placed? The main speakers? Or is the seat 2.15m off the back wall?
By the way, Zero D's suggestion of applying the correct amount of digital delay with the sub(s) as close to you as possible is a good idea:
Direct bass sound will be far stronger than the reflected one, plus you will play the subs at far lower levels exciting the room far less.
The downside is this restricts the correct listening position only to your sofa, you will have profound bass peaks and cancellations in different places of the room, and any port noises or sound besides bass WILL betray the sub's position.
One last thing: Contrary to popular belief, long-firing-short placement could be advantageous in a biggish (wide enough) room, particularly with twin subs. These, combined with the main speakers destroy the long-dimension standing wave, exciting lots of different sets of room modes.
Yeah, that length sounds about right, plus or minus an inch or so. I'm going to have to mess with the delay some more, when I hook the MiniDSP up again, I'll try to get the delay set properly with that, I think it's a little more precise than the receiver's distance setting.
The seat is a little closer than 2.1 meters from the back wall, I'll have to measure it, but it just clears the door, so I'd say it's more like 1.2 meters when it's in the long position, when it's in the short, the seats are right up against the wall.
The null in the 40s is one of the major things that bugs me too. Could it possibly have anything to do with 2 of the walls being solid (studs are fastened to the foundation on the front wall+left wall (when it's in long mode) and left+back wall (when it's in short mode). The wall where the door is is half foundation on one side of the door and standard stud+drywall on the other half.
Could it be possible that with some walls that "give" a little and some that are almost completely rigid, that could cause some issues? There might even be some standing waves that appear on walls in the adjacent room(s) and have an effect through the not-so-rigid walls perhaps.
I do remember while I'm in the adjacent room (where all the electronics are) reversing the polarity of one sub makes the bass in that adjacent room much stronger. It still has the cancellation effect in the main room, but it was a little strange that the bass you hear in the adjacent room was much more powerful, I didn't measure it, but it sounded like around +6 db. Perhaps my walls are just not strong enough and some re-doing is in order.
I think this coming week I'm going to get some casters for the sub cabinets and take all the furniture out of the room and just wheel them around to various locations with RTA running. I'll try the mid-long wall placement and see what that gets me.
Maybe my cure in the end is going to be to just build 2 more subs.
Attached are my first stab at filling in all the material dimensions and a cutsheet for the design posted by Oliver. I plan to use Baltic birch 13-ply material (60" x 60" x 0.75") that I will buy from a local wood supplier in Maryland. I only have MS Paint and PowerPoint so my level of accuracy is not that of tb46 who has more powerful tools, but MAY be good enough. Due to the precision of Oliver's numbers, I will have to do some rounding when actually start to cut wood. There is a typo in the dimension sheet, should be 16.987 for sides instead of 15.987.
I finally received my orders, so will be headed back to the US in August...
Outstanding! I'll be waiting to see how this design works out too. Glad to hear you're coming home.
Edit: That's one hell of a front panel, probably need some serious chamfering.
Attached are my first stab at filling in all the material dimensions and a cutsheet for the design posted by Oliver. I plan to use Baltic birch 13-ply material (60" x 60" x 0.75") that I will buy from a local wood supplier in Maryland. I only have MS Paint and PowerPoint so my level of accuracy is not that of tb46 who has more powerful tools, but MAY be good enough. Due to the precision of Oliver's numbers, I will have to do some rounding when actually start to cut wood. There is a typo in the dimension sheet, should be 16.987 for sides instead of 15.987.
I finally received my orders, so will be headed back to the US in August...
That's my kind of a Baffle! Good work, I think it's best to check this design in a simulation when stuffed.. Normally a TL is using a Sd/3 Terminus for Drivers where x-max is around 10 mm but should be increased for long throw types. I guess only MJK:s programs can solve this matter satisfactorily.
b
Thanks Bjorno, I downloaded the data you provided to another build for a similar design using a Goldwood driver (Oliver posted a link on page 14 - attached below). The thread starter did not go with the design, so I thought I would give it a go.
These two (eventually 4 if I get crazy) will be paired with the awesome TTQWT you developed for my Mael-X driver.Construction to start in September! Based on the quality of the design will use primarly 0.75" Baltic Birch (the real stuff in 60"x60" sheets).
You and Oliver have been beyond helpful! Thanks...
These two (eventually 4 if I get crazy) will be paired with the awesome TTQWT you developed for my Mael-X driver.Construction to start in September! Based on the quality of the design will use primarly 0.75" Baltic Birch (the real stuff in 60"x60" sheets).
You and Oliver have been beyond helpful! Thanks...
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@ DrDyna,
it's possible the drywall (which is right behind your ears) is resonating around 40Hz absorbing energy, or even the door (or even the room behind the door if it is a very small one). Note that the dip is also present at the short-firing-long graph. What happens with the door closed? Even some heavy piece of furniture may be the culprit.
Of cource, given your room's length, it is normal to have a dip at 40Hz (it's rigjt between the peaks of 27 and 53Hz), only it seems too pronounced in this case.
On the other hand, in-room measurements under 200 Hz, are always extremely unreliable...
it's possible the drywall (which is right behind your ears) is resonating around 40Hz absorbing energy, or even the door (or even the room behind the door if it is a very small one). Note that the dip is also present at the short-firing-long graph. What happens with the door closed? Even some heavy piece of furniture may be the culprit.
Of cource, given your room's length, it is normal to have a dip at 40Hz (it's rigjt between the peaks of 27 and 53Hz), only it seems too pronounced in this case.
On the other hand, in-room measurements under 200 Hz, are always extremely unreliable...
The room on the other side is about 50% of the size of the main room. There's 3 rooms down there where one wall is shared with the media room, so it could be any one of them.
I've been busy for the last couple of days trying to install this infernal shower stall that I've been rooked into doing, hopefully I'll have some free time in a couple more days to mess with it some more.
I did get a set of casters for the subs so I can wheel them around to various locations a lot easier
Well, it turns out my S/O really doesn't like the look of the room turned, so my only option for now is to have them at the back of the room about 3 feet away from the MLP.
UGH. I might have to just go ahead and build two more of these.
Edit: Before I get too far along in the thought process, what does everyone think would be the best positioning for 4 of them? One on each wall centered? 4 corners?
Hm.
UGH. I might have to just go ahead and build two more of these.
Edit: Before I get too far along in the thought process, what does everyone think would be the best positioning for 4 of them? One on each wall centered? 4 corners?
Hm.
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Have you tried them in diagonally opposite corners or something like that?
Building 4 would be awesome, and (assuming you have some signal processing to hand) the extra headroom would allow you to pretty much use a brute-force eq solution for the room response.
If there's no DSP available, I'd set off with one in each corner, then try one on each wall, and just play around. I appreciate these things aren't small, so "playing around" with positioning isn't exactly trivial...
Chris
Building 4 would be awesome, and (assuming you have some signal processing to hand) the extra headroom would allow you to pretty much use a brute-force eq solution for the room response.
If there's no DSP available, I'd set off with one in each corner, then try one on each wall, and just play around. I appreciate these things aren't small, so "playing around" with positioning isn't exactly trivial...
Chris
I've tried them front wall at corner and 25%, mid wall and back wall. At each location I tried them facing each other standing up, facing each other laying on their side, facing the back, facing the front (away) and facing up.
I've seriously tried almost every conceivable position, the only ones that measure even remotely decently are the ones at the back of the room where you're sitting (and mic) so close to them that the room doesn't get a chance to come into play.
They're on stands right now in the back that put the driver at the mid-point of the wall, but I'm also considering inverting them and sticking them against the ceiling.
I do have a MiniDSP, but I'm trying to get it as close as possible before I start using it. I've only got an EP2000, so I'd rather EQ through subtraction rather than have to boost anything, as I readily run into the amp's headroom and flick the clip indicators as it is.
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