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Super THT build thread - Page 5

post #121 of 243
12/21/09 at 3:32pm
Thread Starter 
Quote:
Originally Posted by maxmercy View Post

Here's the link to the Audyssey setup guide:

http://www.avsforum.com/avs-vb/showt...5#post14456895

JSS

Yeah I saw that thread, pretty amazing all the stuff you have to take into consideration for the Audyssey set up!
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post #122 of 243
12/21/09 at 4:28pm
The details are really only for the super-nitpicky folks. If you think about what Audyssey does, it would take many hours to do manually, not just 25 minutes....

Audyssey sets levels, delays, and figures out the best compromise in equalization for several seats. It will also correct for other problems. That's huge. My old receiver only allowed you to set one delay (center channel), and the instrctions said to measure the distance with a tape measure between mains and center and set accordingly. The level settings were done with the old Rat Shack spl meter, and were subject to all kinds of room effects which you could not correct for. It did have a center channel 6 band graphic eq, but without measuring equipment, it was pretty useless.

Can't wait to hear what you think of this beast.

JSS
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post #123 of 243
12/21/09 at 9:33pm
Thread Starter 
Here is a pic as we finally finished the structural portion of the THT, the aesthetic portion of the project will have to be left for later at least a month or so. You can see where on the bottom edge of the THT there is newspaper that got glued into the seem (better the newspaper than the floor) Will end up getting all that off when doing the sanding portion of the project during the aesthetic portion of the project.

Here is the BEAST nestled into it's spot in my living room, not very easy to really tell just how big it is in this picture...

Now THIS picture really shows just how big the THT 30" really is!
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post #124 of 243
12/21/09 at 9:40pm
Big sumbitch. Did you get it fired up yet?
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post #125 of 243
12/21/09 at 9:45pm
Wow it is huge. The newspaper adds character man. And am i seeing the speaker terminal on the bottom of the sub? The build quality looks store bought but we all know its 10x better. Baltic Birch sure is some good looking wood.
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post #126 of 243
12/21/09 at 9:47pm
Thread Starter 
Quote:
Originally Posted by Air Supply View Post

Big sumbitch. Did you get it fired up yet?

Gotta wait for the PL to dry on the access panel flange. Also gotta look back at the other build threads and see how people attached the access panel (what kind of screws and such) also gotta place the weather stripping on the flange as well. I need to pick up some locking washers as well then mount the woofer and do leak checking. Still a few steps to take, but I am slowly making headway towards firing this thing up!
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post #127 of 243
12/21/09 at 9:49pm
Thread Starter 
Quote:
Originally Posted by reecew View Post

Wow it is huge. The newspaper adds character man. And am i seeing the speaker terminal on the bottom of the sub? The build quality looks store bought but we all know its 10x better. Baltic Birch sure is some good looking wood.

Yeah I soldered up the terminal to the speaker wires then glued the terminal plate in. I am very excited about the build quality I was able to achieve with Joe's help!!
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post #128 of 243
12/21/09 at 9:58pm
Oh my Lord....that french door (and the big windows, hanging pictures and clock) is bang in trouble.... You better have some plywood handy to patch that thing up when the glass panel on that door breaks...

Actually, I am not joking about this. Be careful when you really push this thing, stay away from sustained sine wave testing, you don't want to 'accidentally' find the resonance freq of any of those glass panels.... My spl meter regularly hits into the mid 120s dB-wise a couple of feet from the horn mouth at 10dB below reference, the amp never gets past lukewarm, pushing out only 80 Watts or so...I took out all the hanging mirrors and pictures in the room, they just moved too much for me to be comfortable...

Should look real nice when finished up....

How much does it weigh?

JSS
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post #129 of 243
12/21/09 at 10:12pm
Thread Starter 
I won't be doing any sine wave testing any time soon, just gonna run Audyssey and call it good for now. I would guess that this thing is in the 60-70lb range, without the woofer in it.
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post #130 of 243
12/22/09 at 9:33am
Oh my!! That thing is of EPIC proportions!

Definitely make sure you check for leaks around the driver and around the access panel cover before putting any considerable power into it. MaxMercy's recommendation of airline tubing found at the pet store using it as a stethoscope works perfectly for this purpose.

http://www.petsmart.com/product/inde...ductId=2752199

$10 bucks says that clock next to the mantel falls down within 2 mins of putting 30 watts into it!
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post #131 of 243
12/22/09 at 10:40am
Full of Awesomeness!!

I couldn't go with the 30" because it wouldn't have fit through my front door. LOL
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post #132 of 243
12/22/09 at 11:15am
Thread Starter 
Quote:
Originally Posted by mynym View Post

Oh my!! That thing is of EPIC proportions!

Definitely make sure you check for leaks around the driver and around the access panel cover before putting any considerable power into it. MaxMercy's recommendation of airline tubing found at the pet store using it as a stethoscope works perfectly for this purpose.

http://www.petsmart.com/product/inde...ductId=2752199

$10 bucks says that clock next to the mantel falls down within 2 mins of putting 30 watts into it!

Thank you! You and Max have been very supportive with giving your knowledge of this build, I really appreciate it. I am the most nervous about making sure I have no air leaks. I am picking up the same type of screws you used on your access panel tonight after work. Gonna try and get this big guy running tonight! I am so excited, but still pretty stressed out about making sure there are no leaks
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post #133 of 243
12/22/09 at 11:17am
Thread Starter 
Quote:
Originally Posted by maxmercy View Post

What version of Audyssey? What else will be in your audio chain from receiver to sub? This is VERY IMPORTANT. Audyssey can inadvertently give a 9dB boost to subsonic frequencies.


JSS

So does our version of Audyssey inadvertently boost at subsonic levels? Or is that the old Audyssey that did that?
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post #134 of 243
12/22/09 at 7:24pm
Here's how Audyssey does it:

NOTE: this was an old setup, when I first fired up my THT in the middle of the room....

Here's the sub output with Audyssey OFF:



Here's the sub output with Audyssey ON:



Here's both together (relative levels):



You can see the rolloff of signal from the electronics below 10Hz in each of the images.

You can also see what Audyssey does is the following:

1. It places cuts at any peaks you may have in your response.

2. It doesn't make any adjustments below a certain frequency (about 20-22Hz in my case).

3. It then BOOSTS the ENTIRE signal to acheive equal loudness between the Audyssey 'ON' and Audyssey 'OFF' settings. It does so in this case by about 10dB....

This is SIGNIFICANT, it is 10x the power!!! In the frequency band where subwoofers do poorest!! I don't know of many subwoofers that have 10dB worth of headroom below 20Hz. This is why I needed a 2nd highpass (Reckhorn B-1) in addition to my amp's built in one, to keep those subsonics from generating sonic distortion....

I have shown these images to Chris Kyriakis of Audyssey, and he agrees, it is a glitch, but that most people (not listening anywhere near reference) may not notice the effect, and I agree. Unfortunately, any updates to the Audyssey algorithm will go unseen by us, as our receivers do not do firmware upgrades easily.....sucks.

But I put up with this 'boost' because of the EQ Audyssey provides my mains/center/surrounds, and sub. The difference between Audyssey on and off when a sound effect is panning across several channels is night and day....

So, be careful at first. set that 18Hz highpass to ON when you first listen, and if it is OFF, approach high volumes carefully.

JSS
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post #135 of 243
12/22/09 at 7:35pm
Quote:
Originally Posted by superedge88 View Post

Now THIS picture really shows just how big the THT 30" really is!

Oh my-my-my, I really like the look of that "Cerberus" in your living space.

Looking forward to your listening impressions.
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post #136 of 243
12/23/09 at 10:01am
Thread Starter 
So I got the woofer bolted down, got the access panel screwed in with gasket, and I tested it out last night. Unfortunately I didn't finish up with all the wiring woofer mounting, Audyssey etc. until about 2 am, So I wasn't able to really crank it. I was however AMAZED at the quality of the bass even at low volumes. This sub OOOOOOOOOZES BASS!!! It is some of the sweetest, most effortless, smoothest bass I have ever heard. I played the scene in War of the Worlds where the machine comes out of the ground and starts shooting people with the lazer... WOW!! I didn't have it cranked, but this morning my wife told me that she was definitely aware of some bass tones while she was trying to sleep.
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post #137 of 243
12/23/09 at 11:46am
Thats awesome i cant wait to get mine done and up and running. I have never even heard a horn before so im kind of excited to hear this.
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post #138 of 243
12/23/09 at 5:36pm
Very nice...Sounds like you have a winner....

I can't believe the Audyssey chirps didn't wake up people in the house....they can be pretty loud. I bet Audyssey set your sub way down from your other speakers....mine was at -10dB with my sub amp's gain set at 10 o'clock...

JSS
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post #139 of 243
12/23/09 at 6:53pm
Thread Starter 
Quote:
Originally Posted by maxmercy View Post

Very nice...Sounds like you have a winner....

I can't believe the Audyssey chirps didn't wake up people in the house....they can be pretty loud. I bet Audyssey set your sub way down from your other speakers....mine was at -10dB with my sub amp's gain set at 10 o'clock...

JSS

That is hilarious, I had MY amp set at 10 oclock and Audyssey set the sub at -10.
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post #140 of 243
12/25/09 at 4:22pm
Thread Starter 
Does anyone have some ideas as to what is going on with my Dayton sub amplifier? I started a thread about it here:
http://www.avsforum.com/avs-vb/showt...4#post17786954
It keeps cutting out, then I have to turn it back on to regain output.
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post #141 of 243
12/25/09 at 5:33pm
Posted over there.

dbl
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post #142 of 243
12/25/09 at 5:47pm
Thread Starter 
still stumped.
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post #143 of 243
12/27/09 at 8:45pm
Thread Starter 
Ok, I got a 20 hertz test tone burned, and retested for air leaks, found none. I then played the test tone while checking voltage at the amplifier, even with volume turned all the way up to 0 I was getting 5 volts AC current. This is with the Audyssey setting the gain of the output at -10db and the gain on the amplifier set to about the 8:45 position. I am barely getting things moving with the gain set this low on the amplifier. But when I play War of the Worlds at that same volume level at the 9:00 position the amplifier goes into protect mode, I have to back it slightly off of the 9:00 position to keep it from kicking off, and the bass is lacking at that point. My multimeter ranges too slowly to capture what voltage level that the amplifier goes into protect mode at. So I am not sure how to trouble shoot it further. Seems to me that I have a bad amplifier.
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post #144 of 243
12/28/09 at 6:21am
Super,

I'm not at all familiar with Audyssey so bare with me. Is there a way you can you run everything without it for the time being? Just to test things out here.


dbl
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post #145 of 243
12/28/09 at 8:57am
Quote:
Originally Posted by superedge88 View Post

Does anyone have some ideas as to what is going on with my Dayton sub amplifier? I started a thread about it here:
http://www.avsforum.com/avs-vb/showt...4#post17786954
It keeps cutting out, then I have to turn it back on to regain output.

Check this out:
http://mpikas.blogspot.com/2007/12/d...amplifier.html

The last thing you need is 6dB of boost at 30 Hz.
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post #146 of 243
12/28/09 at 9:33am
Thread Starter 
Hmmmmm, so I gotta find out if this Dayton amplifier does a 6 db boost at 30 hertz, that could definitely be a contributing factor. Thanks Bill! I am awaiting Dayton's help in this matter.
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post #147 of 243
12/28/09 at 10:04am
Quote:
Originally Posted by maxmercy View Post

Here's how Audyssey does it:

NOTE: this was an old setup, when I first fired up my THT in the middle of the room....

Here's the sub output with Audyssey OFF:



Here's the sub output with Audyssey ON:



Here's both together (relative levels):



You can see the rolloff of signal from the electronics below 10Hz in each of the images.

You can also see what Audyssey does is the following:

1. It places cuts at any peaks you may have in your response.

2. It doesn't make any adjustments below a certain frequency (about 20-22Hz in my case).

3. It then BOOSTS the ENTIRE signal to acheive equal loudness between the Audyssey 'ON' and Audyssey 'OFF' settings. It does so in this case by about 10dB....

This is SIGNIFICANT, it is 10x the power!!! In the frequency band where subwoofers do poorest!! I don't know of many subwoofers that have 10dB worth of headroom below 20Hz. This is why I needed a 2nd highpass (Reckhorn B-1) in addition to my amp's built in one, to keep those subsonics from generating sonic distortion....

I have shown these images to Chris Kyriakis of Audyssey, and he agrees, it is a glitch, but that most people (not listening anywhere near reference) may not notice the effect, and I agree. Unfortunately, any updates to the Audyssey algorithm will go unseen by us, as our receivers do not do firmware upgrades easily.....sucks.

But I put up with this 'boost' because of the EQ Audyssey provides my mains/center/surrounds, and sub. The difference between Audyssey on and off when a sound effect is panning across several channels is night and day....

So, be careful at first. set that 18Hz highpass to ON when you first listen, and if it is OFF, approach high volumes carefully.

JSS

That first graph is not possible. Something wrong there. The second graph looks like a true in-room response. I don't know what the first one is measuring, but it is not the output of your sub.
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post #148 of 243
12/28/09 at 10:40am
Quote:
Originally Posted by Fatawan View Post

That first graph is not possible. Something wrong there. The second graph looks like a true in-room response. I don't know what the first one is measuring, but it is not the output of your sub.

Please explain to me how the first graph is NOT possible from the SUBWOOFER LINE OUT of the receiver.....

None of the graphs are in-room response, they are all sub line out, to see what Audyssey does.

JSS
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post #149 of 243
12/28/09 at 10:54am
Thread Starter 
Looks like it is fixed. It turns out that the Dayton amp needs more signal power from the receiver, so all I had to do is go up to +5 dB on the receiver and adjusted the gain on the Dayton accordingly and now I have HUGE clean POWER!!! The THT is AMAZING!! I am so pleased and proud of this work of art. Can't wait to show it off! Thanks for everyone's help, especially you Bill!!!! I will update this thread once I do more work on the aesthetics of the sub.
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post #150 of 243
12/28/09 at 11:02am
Quote:
Originally Posted by maxmercy View Post

Please explain to me how the first graph is NOT possible from the SUBWOOFER LINE OUT of the receiver.....

None of the graphs are in-room response, they are all sub line out, to see what Audyssey does.

JSS

Ahhhhh--that makes sense. Your post says "this was an old setup, when I first fired up my THT in the middle of the room....

Here's the sub output with Audyssey OFF" It didn't mention anything about sub line out from the receiver.
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