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Twelve 10" NHT Subwoofer Build. - Page 8

post #211 of 274
Thread Starter 
The one above did have sound from the speakers with the SPL meter reading them.

But here's the graph when I ran the LFE directly back to the computer, nothing to the sub amp, and the fronts were turned off. Basically no sound, just the loop to the computer.

I have no idea what that actually shows though.





I don't think that looks like your example, maybe I missed an option to check, but I don't think so. I'll double check in the morning.
post #212 of 274
one thing at a time

1 calibrate the loopback on the left RCA out

2 verify it works correctly on the LFE RCA

3 Calibrate REW dB level with Meter

4 Measure till your hearts content
post #213 of 274
Maybe step one should be pick up phone
post #214 of 274
Thread Starter 
Sorry Dan, I went to bed after that last post.

Did I do any of that right? I followed the program directions and your directions as well. But maybe I missed something.

Is it all wrong?

I have some family stuff I 'have' to do for most of the day, hoping to get back to this later tonight.
post #215 of 274
Erich,
you are getting close, but I think you need a walk through. Any idea when you will be ready to start?
post #216 of 274
Erich,
everybody has their moments. Yesterday I wanted to crush my iPod, it was my first attempt to use a Nike+ sensor with it and I had nothing but trouble. I ended up running and walking ~2 miles total just to try and calibrate it. By the time I had that done I was so frustrated I wanted to throw it in the trash. Today I'm going out to for my second attempt to get my calibrations correct.
post #217 of 274
Thread Starter 
Uh Dan, it can't be that cold up there yet to warrant a treatmill at the gym....is it?


I am glad you said that though. This is really making me feel like an idiot. Granted this is all new to me, but I've done a lot of electrical work, and many other fields of work. But this computer stuff figuring box specs prior to builds and calibarating after the build is a bit of info overload.

I realize that the next time around it will all look much easier, but it's very aggrivating right now. I actually posted a couple on Saturday that I was just going to give up on this for a while before I through the computer out teh window!





For what it's worth, I had to unhook all of the computer stuff tonight because I had friends over. I watched Pans Lab (again) and they were all blown away. And I was far from max. I told them I still had to tune the subs and explained what needed to be done. They looked at me like I had 3 heads and said "Uh, you have a wall of subs up front and 2 giant tubes in the back.....and you're not happy yet.....Erich, you're nuts."

Maybe they're right? But they sure liked it!




P.S. - I hate to break it to ya, but I didn't see any Nike info uploaded earlier today after you made that post. BUT, I'm now seeing 1 workout, 1.99 miles, pace of 7' 42"/mile (?), and last workout being 2 miles.
post #218 of 274
Erich,
good to hear you at least got some quality time on the system. IMO if you can't at least have that then then why bother.

Run outdoors? Me? At these temps? He he, you are out of your tree. I used to bike, but my knee..... Basically one leg gives me trouble in one area or another from overuse, be it from the running or biking. Oh well.

I was out and about right up until I got on AVS, so I wasn't home to upload the run. That was the first run, I used it to calibrate the Nike+. I tried it on an elliptical trainer machine, it didn't have a clue how fast or far I had gone. But it did seem to be more accurate when I got back on the treadmill and tried some walk run intervals. I beat up the bottom of my foot a bit and I'm trying to rehab it.

But back to your setup, just call or text me whenever you drag out the PC and I'll walk you through it. I've done this sort of stuff over the phone for other forum members.
post #219 of 274
Erich,
have you tried running just the subs up front and raising the crossover point, say ~120-160Hz that'll get you some punch and ease the load off the mains.
post #220 of 274
Thread Starter 
No I haven't tried that yet, but I will. I did take the crossover up to 90, but that was it and that's where it is now.

I didn't know if I could go up that high or not. But it might be nice. My receiver allows me to change the crossover or EQ for each speaker. Would I set the crossover for the center that high as well?

I'm hoping to have time to get the computer all wired back up tomorrow. I'll go even slower this time.
post #221 of 274
I saw earlier that you had your main speakers set for large. Try setting them for small, and then adjusting a crossover point that you may like better. This will also send all LFE as well as the bass to your subs.
post #222 of 274
Quote:
Originally Posted by Jim Hef View Post

I saw earlier that you had your main speakers set for large. Try setting them for small, and then adjusting a crossover point that you may like better. This will also send all LFE as well as the bass to your subs.

Yea, I agree with Jim here. Any and all of your speakers will need to be set to small. Running them full range would be punishing as they have no chance of keeping up with your bass array. The suggestion I made for setting the AVR to large was only for calibration.
post #223 of 274
Thread Starter 
Yes, I only had them set to large for the calibration testing. Sorry if I didn't make that clear.

Hey Dan, is there any evening that's better for you for a quick phone call?

This is going to be a fairly busy week, but I am going to try and take a day off at some point to go back to this calibrating.

My slow work time starts next week, so I can always wait until then if you're going to be busy.



After "showing off" my theater to some friends/family last weekend, I've now been "forced" into a solid week of classic Halloween scare movies......each night until Saturday! But I can change movie times as needed.
post #224 of 274
now is as good as any
post #225 of 274
Thread Starter 
Okay, more GRAPHS!

Warning: These are just trial curves to see if I'm on the right track getting the meter set up properly. I'll likely delete them once I figure it out.....because they probably aren't correct. The SPL level is not right.

Curve:




Curve and LFE calibration curve (or something like that)







This graph shows the sound card as red, then the LFE calibration test as green and the curve as blue.


post #226 of 274
I think it looks fairly normal considering the roll off of the RCA outs
I bet that just roars


Looks like the crossover could go up to 120Hz
post #227 of 274
Erich,
I posted over at HT Shack and I think you will need to run off a full range output instead of the LFE out from your AVR. Apparently the roll off of the high end is causing the error message.
post #228 of 274
Thread Starter 
So do you mean I need to calibrate the sound card using the right speaker output AND do my testing using the same output?
post #229 of 274
Quote:
Originally Posted by Erich H View Post

So do you mean I need to calibrate the sound card using the right speaker output AND do my testing using the same output?

Yea, Bruce said REW looks at the level at the end of the sweep. So I think eliminating the crossover should help. But He also mentioned that you may need to ignore the message and accept the sweep. I'd do it just to see what you get.
post #230 of 274
Looks like these drivers have sold out.
post #231 of 274
I believe they just about sold out when EricH wanted his. Unless I am mistaken Jack sent Eric the VT3 10" sub which is better but costs $30 each.

Pick up some of those VT3 drivers, Jack is great to deal with.
post #232 of 274
MJ is correct. I've still got around 30 of the 10" drivers that Erich used in his sub.
post #233 of 274
Quote:
Originally Posted by NEO Dan View Post

Yea, Bruce said REW looks at the level at the end of the sweep. So I think eliminating the crossover should help. But He also mentioned that you may need to ignore the message and accept the sweep. I'd do it just to see what you get.

Most of the time if you ignore it it still produces a good measurement.
post #234 of 274
Thread Starter 
Quote:
Originally Posted by NEO Dan View Post

Yea, Bruce said REW looks at the level at the end of the sweep. So I think eliminating the crossover should help. But He also mentioned that you may need to ignore the message and accept the sweep. I'd do it just to see what you get.

Well, I went back down to try all this again. I got no where.

Dan, when I talked to you on the phone, I think we ran through so many scenerios there towards the end that I am now completely lost.....worse than before possibly. I know we switched inputs a few times, changed the line in, and the mic set ups, and now I'm not sure if they're suppose to be put back, or left the same. And I'm not even sure what the defaults were at this point.


Is the sound card calibration you helped me with actually okay to use? I thought we ran that through the whole frequency response?


I'm debating whether to use the 3 or 5 pound sledge hammer to work on the sound card at this point.
post #235 of 274
Erich,
I'll be headed home this evening, I'll give you a ring on my way back home.
post #236 of 274
Thread Starter 
Okay, I know it's been a little while, but I was having issues getting this to work out right. I do believe the following is the correct REW graph.

I'd really like to thank Neo Dan for helping to get this calibration correct. He spent quite a bit of time on the phone walking me through it. Assuming the sound card is calibrated correctly, which I believe it is, here's the graph for the 10's. I do have a Feedback Destroyer but it's not hooked up yet.






I have two 15's in the back of the room that I also use, but just for movies. I ran the sweep with the 10's and the 15's on at the same time just to see what it would show. It's the blue line. The 15's were just a quick thing I threw together, and sadly their cheap dinky crossover has a high pass at around 20hz......I need to get rid of that. But either way, here it is.

post #237 of 274
Quote:
Originally Posted by Erich H View Post

Okay, I know it's been a little while, but I was having issues getting this to work out right. I do believe the following is the correct REW graph.

The graph looks impressive but what do your ears or better yet, structural integrity of your home tell you
post #238 of 274
Thread Starter 
Quote:
Originally Posted by mjaudio View Post

The graph looks impressive but what do your ears or better yet, structural integrity of your home tell you

They sound really nice and solid, I'm still unsure how much I can crank these up though. I guess I have no reason to worry, but I don't want to do any damage to the subs. And I don't want to have to worry about what type of bass might be coming up in a movie that may push them too hard.

I should get a short video posted on their excursion so you guys could tell me how they're looking from that stand point and how much more room I have to play with.

Going by that graph, do you think I need to hook up my Feedback Destroyer?
post #239 of 274
Quote:
Originally Posted by Erich H View Post

They sound really nice and solid, I'm still unsure how much I can crank these up though. I guess I have no reason to worry, but I don't want to do any damage to the subs. And I don't want to have to worry about what type of bass might be coming up in a movie that may push them too hard.

I should get a short video posted on their excursion so you guys could tell me how they're looking from that stand point and how much more room I have to play with.

Going by that graph, do you think I need to hook up my Feedback Destroyer?

If your pushing about 250 watts per driver your probably OK. I am no expert but usually sealed subs are more friendly than vented as far as damaging woofers. You will probably hear potential damage from clipping before damage occurs.

With as much headroom as you have with 12 10" woofers your ears will probably be damaged before the woofers.

With adding an eq you can get some of those peaks down. Are you using a lower x-over than 80hz? The level at 80hz is at about 84 db's and at 48hz is at 98db's or so.

Using a feedback destroyer can be challenging at first but rewarding if used right. I cheat and use a Velo SMS-1 but have a FBD as well for a different system.

Get yourself a SPL meter and just set the levels of your subs to match the mains and add a little extra juice if needed. I usually go about 3 dbs more for movies but with your massive array matched with your mains may be the ticket.

Now NEO Dan and Jack can chime in and tell you what to really do.......Subwoofer masters the both of them!
post #240 of 274
Thread Starter 
I think my crossover is at 90. Dan said I could move that up a bit closer to 100 or more, so I'll do that soon.

Yeh, Dan also mentioned I shouldn't have any issues with them bottoming out with the power I have. But the comment of "shouldn't" is what worries me.

I haven't set anything to 'reference level' yet because I was doing the other testing. I'll work on that this week.
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