Ok, I'm at it again.
I'll try to make this short and sweet.....
As most of you know my front wall is 15ft wide. I have my 2 m60's, 1 vp150, and 1 EP500 up on the stage below my screen. I was talking to a guy from Triad Speakers the other day over on AVS, and he said he has found the best overall placement of his two subs to be at the "third wav". Sounded like the center of the drivers are the same distance from each other, and from the left/right walls. I believe his wall was 11ft wide, so the subs were exactly 3'8" from each other and the walls. This has given him a very flat response, tight, even, and extended result. Prior to having two subs, he said just placing one at the "third wav" gave great results.
I've trying to move my EP500 from side to side to find the best location on my stage. What the heck is the third wav and how do I calculate? Is this saying to just divide the width by 1/3rd which would be 15ft / 3 = 5ft? Right now I've moved the EP500 back to dead center, I just can't make up my mind..
Thanks, Randy
I forgot to mention I've tried the sub crawl, but not sure I heard much difference to my ears, didn't use the spl meter at the time. I will also try jakeman's suggestions below from another thread for calibration. Just concerned about placement...
1. Turn off auto-calibration.
2. Calibrate all your speakers first to 75db.
3. Measure distance then set delay for each of them. You may want to set the surround speakers to slightly more delay for effect.
4. Turn off sound to all speakers.
5. Set the subwoofer volume to -7 (a quarter of the way down to leave you some room for fine tuning).
6. Run the LF sweep on S & V and adjust gain at the sub so the needle spends most of its time at 75db at your favourite seating position.
7. Go and move the sub around to see if you can get less flucuation on the SPL metre at 75db.
8. Play sound through the mains and sub.
9. Flick the phase switch to see whether 0 or 180deg has more SPL at the seating position. Leave the phase at the higher setting.
10. Measure the distance to the sub and input the delay setting for the receiver. Many subs benefit from increasing delay another 3-5 feet than the measured distance depending on room acoustics, so experiment.
11. Test with your favourite music or movie. I you want more bass increase your receiver setting not the gain at the sub.
12. Start over again at #1 and fine tune your calibration.
Randy, I'm not familiar with what Triad suggests, but it's very likely that you've interpreted it correctly, i.e. one-third of the way in from the side wall. It doesn't strike me as a universally superior location. For example, with two subs the paper by Dr. Toole's people at Harman(which I believe you've read)suggests center of side walls or center of front and back walls as being good locations for the two. Right in the corner is still a good spot for a single sub unless the room is nearly square, which might make that one-third out location better.
Hi Randy
I've never had much luck with the quick placement formulae because nodes will vary considerably from room to room, so one persons placement doesn't always translate to another's room.
From the pics of your great looking room, I'd say you still have a few challenges finding ideal placement because of its large irregular layout. I had a similar situation with my irregular space until last year when I built another small wall to seal the room. The larger the volume the more difficult it will be for one sub to pressurize the room.
With only one sub your situation may actually work better with the 500 in the corner. FR will be less linear but the overall result could be better depending on your seating position . Generally speaking I've found one-third to one-half distance from a corner works best with one sub if your goal is flatter response. As you move closer to the corner you benefit from more room gain but less linear FR. Given the size of room and layout a second EP500 along the front wall or one on the frontwall and another on a sidewall should really perform well.
Another suggetion would be stay with one 500 and get an SMS-1 to equalize FR at the main seating area. It's graphical display will also help you pinpoint the ideal placement.
Randy. As I looked again at your room layout, one spot jumps out which is left midwall 10-12 feet down from the left corner. Besides better FR it is nearfield the seats which will provide more output to the seats in that large space. I'd check that spot before the left corner.
If it was my space I would go with mutiple subs.
>>>
If it was my space I would go with mutiple subs.What??? Mr. Jakeman would actually go with *multiple* subs? Say it ain't so.
Rick I'm afraid its true. They call the condition multipleaxiomsubwooferitis. Its been know to afflict otherwise healthy people, especially males, who live in large rooms.
Drank a few too many beers at the Oktoberfest thing last night so I have decided it’s safer to screw around with my speaker calibrations than power tools today.
While messing around with the Avia DVD and the LFE test tones part of the DVD and subwoofer calibrations (with my RS meter), I noticed that when the LFE test tones cycle from L/C/R/SR/SL, the LFE noise is considerably lower on all channels other than the R and L mains. It's right about 10 DB lower actually. I have the X-over set to 80 on all speakers (they are all set to small of course) and I’ve set the AVR sub to a -6 and all the speakers are reading as close as possible with pink noise. I’ve tried everything on my AVR settings (it’s a HK 7300) and I can’t change this phenomenon. The HK also has an option to select L/R, Center, Surround or Surround back. I’ve tried them all and there is no difference.
So my question is, how am I to set the gain on the sub?? Do I match the mains or do I match the other channels??
Quote:
Turn up the sub?
But how much? To match the Mains or the other speakers? If I match the center for example, the sub DB will be about 10 higher than it is now.
I haven't used the test disc you refer to but when testing the sub should you be having signals sent to all the other channels ? To me that doesn't sound right.
I suggest you just calibrate each speaker and sub individually using calibration disc test tones from the dvd player. Do not play the tone through more than one speaker/sub at the same time when calibrating to 75db.
All of the speakers should match, including the sub. Some test disks (DVE, I think) do need to have the sub calibrated 10 db hotter than the rest of the speakers. I don't remember why.
Just finished using my Discwasher Home Theater setup disc this evening. I decided to reset all of my previous Denon auto setup values to default (zero) and try the disc method. The dB levels and delay ended up being different? When I used the receiver test tones and adjusted to 75dB's the end results were 5-7 dB's higher than the CD? For example, when using the receiver, the mains are around +6dB and the surrounds ranged from +5 to +7 dB's. Also, the delay settings ended up being further with the Denon mic setup.
With the Discwasher CD, I first adjusted left speaker. The dB level was at 0dB and I just adjusted the main volume until the meter read 75dB. For the rest of the speakers I adjusted the dB levels for each channel to 75dB. The end result was all the speakers ended up being right around the same setting as the left main. I guess I'm not sure why there was such a difference compared to the receiver setup, isn't 75dB=75dB no matter how you get there?
Anyway, for the sub, the disc said to adjust it to 3dB higher than the other speakers. I also have it currently placed so the middle of the driver is 5ft from the left wall, which is 1/3 of the wall width. Seems to give me good results so far.
I forgot to mention the delay was less when I figured it manually versus the receiver calculation. Most of the speakers I had to reduce by 1-2 ft. The sub was originally set to 26ft per the receiver, infact the sub is only 9ft from the prime location. I used Jakeman's suggestion to add about 5 ft to that number. Things sound much better.
Quote:
All of the speakers should match, including the sub. Some test disks (DVE, I think) do need to have the sub calibrated 10 db hotter than the rest of the speakers. I don't remember why.
Encoding error. Joe Kane Productions screwed up and recorded the .1 track 12db less than they should have. When I use DVE's 6.1 tones for calibrating my side and rear surrounds I set all the speakers to 75db and the subs to 85db to compensate. With Discwasher and Avia you can set all the subs/speakers to 75db. With the RS SPL correction factor the sub will be 2-3 db hot which is where most people prefer it. If you want the subs flat with the speakers then dial in the sub at 72-73db.
Quote:
Encoding error. Joe Kane Productions screwed up and recorded the .1 track 12db less than they should have. When I use DVE's 6.1 tones for calibrating my side and rear surrounds I set all the speakers to 75db and the subs to 85db to compensate. With Discwasher and Avia you can set all the subs/speakers to 75db. With the RS SPL correction factor the sub will be 2-3 db hot which is where most people prefer it. If you want the subs flat with the speakers then dial in the sub at 72-73db.
John, I assume you would then dial in the sub at 82-83 dB if you're using DVE. Correct?
I did all the speakers first, then started the LFE calibration part on the DVD. The first ‘chapter’ starts out by cycling LFE to each speaker and the sub. It will send the LFE to the L main for about five seconds, and then it sends it to the sub for about five seconds. After cycling these two several times, it moves to the center speaker and sub, then the R main and sub, and then the surrounds. The disk instructions are to adjust the sub’s gain until there is no change on the meter (slow response at C). This is where mine are screwed up. When it is cycling this LFE test tone back and forth between the two mains, the Sub’s LFE noise is about 10 DB higher than when cycling between the rest of the speakers.
I’m not real sure why this test is done; maybe it’s there to make sure that the speaker X-over settings are set correctly. I’m going to try changing those some and see what happens. After reading the manual some, the 7300 has the option of selecting the mains as large, all the others as small, but still maintaining the LFE channel and X-over settings. I might give that a whirl too.
Something is not right with my set up though. We watched LOTR’s last night and this time I kept my meter close by. Normal volume during talking scenes and non-action where averaging 60 dbs, but during the action and LFE loaded scenes the volume was hitting 95 dbs. I’m not positive but this seams to be a pretty huge jump. Has anyone else checked volume during this movie??
Hi Jack
Assuming you are using only DVE test tones , its important to recognize that the 0.1 tone is 12db hot. If using the SPL metre a reading of 85 with DVE gets 73db which, after considering the RS correction, is flat with the speakers at 75db. The extra 2db is the metre correction factor. ie. 87 on the metre would be 2db hot while 85 is flat with the other speakers if you have dialled in the other speakers at 75db with the tones. If you are calibrating at 82-83db with DVE your sub is set too low.
I don't recommend or use DVE anymore except for calibrating rear surrounds because of this confusion. A really good cheap calibration disc which I prefer and is easy to use is the Discwasher which I believe is made by the people who did the S & V disc.
Anyway, here is what I do with the various discs while looking at the RS metre, if you want to run the subs flat with the speakers/sub. If you want to run 2db or 3db hot just add it to the sub SPLs on the right:
DVE 75db/85db
Avia 85db/83db
Discwasher 75db/73db
Quote:
Hi Jack
Assuming you are using only DVE test tones , its important to recognize that the 0.1 tone is 12db hot. If using the SPL metre a reading of 85 with DVE gets 73db which, after considering the RS correction, is flat with the speakers at 75db. The extra 2db is the metre correction factor. ie. 87 on the metre would be 2db hot while 85 is flat with the other speakers if you have dialled in the other speakers at 75db with the tones. If you are calibrating at 82-83db with DVE your sub is set too low.
DVE 75db/85db
Avia 85db/83db
Discwasher 75db/73db
Understood, and thank you John.
That calibration doesn't make any sense--cycling LFE to all the speakers? If your speakers are set to small.... all of the LFE should go to the sub! My calibration disk (DVE) merely sends full range pink noise to all of the speakers, and you calibrate them to be the same (other than the sub, which is +12dB as Jakeman explains). There's no separate calibration for LFE. Strange disk you've got there!
Yes, it is a weird disk. It has more friggin tests than I feel like messing with. This particular test that’s been giving me grief cycles pink noise between each speaker, sending LFE’s to the sub and high frequencies to the speakers. The instructions say that the DB’s should be consistent on the RS meter and that the high frequencies have been calibrated to d0 this acurately (I'll just have to believe them). I was incorrect earlier when I said it cycles LFE’s to the speakers and the sub.
I messed around with it some more and I think I got it figured out. The X-over settings do affect the LFE output somehow. When I had everything set to 80, the L and R LFE was considerably higher than the other speakers (about 10 DB). I tried to lower the X-over setting on the mains to 60 while leaving the other speakers at 80 and this didn’t change anything. I then set the mains back to 80 and bumped up all the other speakers to 100, and now when the test tones cycle back and forth, everything is much, much closer. The LFE is still about 2 db’s higher when it cycles to the L/R mains, but it’s right on with all the rest. This is a lot better than the 10 db difference I was getting before. I’m happy now.
Mike I thought it was a little strange the way the Avia disc did that particular test, I just calibrated the sub to match the mains and left the other speakers alone (all X'overs set to 80). Now I'm going to have to drag out the Avia disc and try it again using your crossover settings on the center and surrounds ... see what you did!
What do mean what I did Richard?? You started me down this road buddy. I haven’t stopped screwing with my system sinse I heard yours!!
I’ll tell you what though; I’m a pretty happy camper. I bought that John Fogarty DVD and watched it in DTS 6.1 channel. Man it sounded awesome! The video on that disk is great too. It looks like HD with my Oppo 971 and 900AU.
Now my biggest gripe is figuring out how in the hell I can make this stupid HK default to 7 channel surround instead of 5 channel every frigin time I put in a DVD. It’s really starting to annoy me having to toggle through the Dolby Digital and DTS options when the DVD’s are playing to get it back to DD PL IIx. Same with DTS. Has anyone got that figured out???
If you find out, tell me.
Seems to me the H/K reads and sets up to whatever the DVD is defaulted to ... which never seems to be the mix we want to play the DVD in.