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first attempt at building a sub - Page 5

post #121 of 161
Thread Starter 
Quote:
Originally Posted by VEXXD View Post

Ikea pillows come in a nice little bundle so you don't get as many weird looks when you buy 24 at a time biggrin.gif
Pretty much 1 lb. of poly per pillow so I'll be doing 1 pillow per cu. ft.

Damn man, 24 pillows and I pillow per cu. ft. What in the hell are you building there? eek.gif
post #122 of 161
Quote:
Originally Posted by Smigro View Post

Damn man, 24 pillows and I pillow per cu. ft. What in the hell are you building there? eek.gif

Something that is 24 cuft total. HAHA
post #123 of 161
Thread Starter 
Quote:
Originally Posted by beastaudio View Post

Something that is 24 cuft total. HAHA

LMAO
post #124 of 161
Quote:
Originally Posted by beastaudio View Post

Quote:
Originally Posted by Smigro View Post

Damn man, 24 pillows and I pillow per cu. ft. What in the hell are you building there? eek.gif

Something that is 24 cuft total. HAHA

"I like to sit inside my speaker enclusure......"  Thats the way to get insane bass, talk about room gain!

post #125 of 161
Lol...I'm actually building four separate enclosures smile.gif
post #126 of 161
Thread Starter 
Quote:
Originally Posted by VEXXD View Post

Lol...I'm actually building four separate enclosures smile.gif

Nice, wish I had the room for that.
post #127 of 161
Thread Starter 
So I thought I would make it a little easier on the guy at Home Depot and made up a template for all the cuts that need to be made. Looks like I will be able to get it all done with one piece of 48 x 96 x 3/4 inch MDF...as long as I can find a piece of scrap laying around for my last piece that needs to be 21.50" x 20.75". If not I guess I could have him make cuts for a new a/v rack since it looks like I am about to outgrow my old one.

MDF cuts for sub.pdf 66k .pdf file
post #128 of 161
search and download the program called "Cutlist" you'll love it and it will save you some pencil lead
post #129 of 161
Thread Starter 
Quote:
Originally Posted by beastaudio View Post

search and download the program called "Cutlist" you'll love it and it will save you some pencil lead

Cool, I will have to check it out. thanks
post #130 of 161
Thread Starter 
Because I got curious and started looking around the internet, how would this amp compare to the iNuke? I know it is more wattage than the speakers can handle, but figured I could just keep the gains down as to not do damage to the speakers (is this not recommended to do)?

http://www.amazon.com/Behringer-EP4000-Professional-Accelerated-Technology/dp/B001U5JFNM/ref=sr_1_1?s=musical-instruments&ie=UTF8&qid=1346332510&sr=1-1&keywords=europower

I know the iNuke has a built in DSP/EQ, but I figured for the time I could just let Audyssey do its things until I have the funds to get and external EQ and the laptop to run the software to do it on my own. Really curiousity just got to me and I know that a lot of people seem to use this amp.

The one thing I see that I am not sure of is it says the amp only operates in the 20-20,000 Hz range. Does this mean that I will not get anything below 20Hz to play through the sub? Does the iNuke play below 20Hz? I can't seem to find that in the iNuke specs.
post #131 of 161
EP4000 is a good amp. Cheap power and specs are well documented. It delivers into the single digits just dosent meet their +\- specs that low, probably distortion limited.

Now since its been touched on before i'll chime in on power/driver power handling. Ideally you want to have the amp matched as closely to the power handling of the driver as possible and keep the amp out of clipping.

Now you say, how? Gain Structure + Google.

I like to be power limited and keep the amp from clipping. Mechanically limited setups are prone to damag IMO especially if i get a couple beers in me wink.gif

IOW, a mechanically limited(driver limited) setup can sustain thermal or catastrophic mechanical damage before you even reach for the remote.

Power limited is simple, set gain structure, keep the red lights out, and your good.
post #132 of 161
Thread Starter 
Quote:
Originally Posted by NicksHitachi View Post

EP4000 is a good amp. Cheap power and specs are well documented. It delivers into the single digits just dosent meet their +\- specs that low, probably distortion limited.
Now since its been touched on before i'll chime in on power/driver power handling. Ideally you want to have the amp matched as closely to the power handling of the driver as possible and keep the amp out of clipping.
Now you say, how? Gain Structure + Google.
I like to be power limited and keep the amp from clipping. Mechanically limited setups are prone to damag IMO especially if i get a couple beers in me wink.gif
IOW, a mechanically limited(driver limited) setup can sustain thermal or catastrophic mechanical damage before you even reach for the remote.
Power limited is simple, set gain structure, keep the red lights out, and your good.

If I am reading this right you are saying you would rather have an amp with less power as opposed to an amp that has more power than the drivers can handle? I am new to all of this technical stuff, but I always thought clipping came from not having enough amp power, thus causing the signal to clip which would be potentially harmful to the drivers them self.

I figured by having more power than I need, I could keep the gain down as to not harm the drivers, but also keep the amp from clipping because theoretically I wold not be driving the amp to its limits. Is this not right?

Trying to make my way through this http://www.diyaudio.com/forums/diyaudio-com-articles/186018-what-gain-structure.html , but to me this is like trying to read Chinese. Man I got a lot to learn about this stuff.
Edited by Smigro - 8/30/12 at 7:58am
post #133 of 161
Quote:
Originally Posted by NicksHitachi View Post

EP4000 is a good amp. Cheap power and specs are well documented. It delivers into the single digits just dosent meet their +\- specs that low, probably distortion limited.
Now since its been touched on before i'll chime in on power/driver power handling. Ideally you want to have the amp matched as closely to the power handling of the driver as possible and keep the amp out of clipping.
Now you say, how? Gain Structure + Google.
I like to be power limited and keep the amp from clipping. Mechanically limited setups are prone to damag IMO especially if i get a couple beers in me wink.gif
IOW, a mechanically limited(driver limited) setup can sustain thermal or catastrophic mechanical damage before you even reach for the remote.
Power limited is simple, set gain structure, keep the red lights out, and your good.

It's pretty hard to mechanically damage four 15" drivers with an EP4000... I have one 15" TC Sounds LMS-R and it never even gets close to xmax unless I run a sin wave at 15 hz at 120 dB... And at that point my house circuit would just trip as it's on a 15 A with 10 other components...
post #134 of 161
Quote:
Originally Posted by Smigro View Post

If I am reading this right you are saying you would rather have an amp with less power as opposed to an amp that has more power than the drivers can handle? I am new to all of this technical stuff, but I always thought clipping came from not having enough amp power, thus causing the signal to clip which would be potentially harmful to the drivers them self.
Yes, Clipping is bad.  A properly setup Gain Structure should not allow the setup to clip.

I figured by having more power than I need, I could keep the gain down as to not harm the drivers, but also keep the amp from clipping because theoretically I wold not be driving the amp to its limits. Is this not right?
How are you going to "keep gain down"?  Also the knobs on the front of pro-amps are not gain knobs really they are attenuation knobs.  They adjust how much your input voltage is attenuated.  So then how are you going to know how much power your feeding the drivers?  Not to mention if you EQ, now your apparent amplifier load is not constant but variable.  Not saying it can't be done but its not as easy as you might think.

Trying to make my way through this http://www.diyaudio.com/forums/diyaudio-com-articles/186018-what-gain-structure.html , but to me this is like trying to read Chinese. Man I got a lot to learn about this stuff.
Checkout the hyperlink I posted above about gain structure.  You cannot hope to use pro power safely and effectively until you get the basics of it.
post #135 of 161
Quote:
Originally Posted by WagBoss View Post

Quote:
Originally Posted by NicksHitachi View Post

EP4000 is a good amp. Cheap power and specs are well documented. It delivers into the single digits just dosent meet their +\- specs that low, probably distortion limited.
Now since its been touched on before i'll chime in on power/driver power handling. Ideally you want to have the amp matched as closely to the power handling of the driver as possible and keep the amp out of clipping.
Now you say, how? Gain Structure + Google.
I like to be power limited and keep the amp from clipping. Mechanically limited setups are prone to damag IMO especially if i get a couple beers in me wink.gif
IOW, a mechanically limited(driver limited) setup can sustain thermal or catastrophic mechanical damage before you even reach for the remote.
Power limited is simple, set gain structure, keep the red lights out, and your good.

It's pretty hard to mechanically damage four 15" drivers with an EP4000... I have one 15" TC Sounds LMS-R and it never even gets close to xmax unless I run a sin wave at 15 hz at 120 dB... And at that point my house circuit would just trip as it's on a 15 A with 10 other components...

Well, that depends on the drivers.  Not sure how comparing the TC applies here?

 

I thought he was only running 2?  His parts list only showed 2?

 

4 HFs would be power limited, and like I said, learn gain structure and keep the red lights out.

post #136 of 161
Thread Starter 
Quote:
Originally Posted by NicksHitachi View Post

Well, that depends on the drivers.  Not sure how comparing the TC applies here?

I thought he was only running 2?  His parts list only showed 2?

4 HFs would be power limited, and like I said, learn gain structure and keep the red lights out.

For the time being I will only be running two 15's in a opposed orientation, but plan on adding a second. I think I have to do what you said and learn about gain structure. Like I said, I am new to all of this (building my own subs with separate components) so I definitely have a lot of learning to do.

Regarding your post above this, I thought those knobs were gain knobs, I did not know they were just attenuation knobs (told you I have a lot to learn).
post #137 of 161

FWIW, If I were building your setup, I'd use the NU6000DSP.  Run two drivers each channel wired to 8ohms.  Run one channel until you get the other two subs.

 

  • DSP
  • 1100Wpch RMS= 550W per driver
  • Power limited setup
  • Takes the drivers right to thermal rating
  • Setup gain structure so that clip lights never/barely come on
  • Know your gettting everything out of the drivers and not overdriving them
  • Sit back and enjoy
post #138 of 161
Quote:
Originally Posted by NicksHitachi View Post

Well, that depends on the drivers.  Not sure how comparing the TC applies here?

I thought he was only running 2?  His parts list only showed 2?

4 HFs would be power limited, and like I said, learn gain structure and keep the red lights out.

he's building a box with 2 in it now, then another one later.
post #139 of 161
Quote:
Originally Posted by NicksHitachi View Post

FWIW, If I were building your setup, I'd use the NU6000DSP.  Run two drivers each channel wired to 8ohms.  Run one channel until you get the other two subs.
  • DSP
  • 1100Wpch RMS= 550W per driver
  • Power limited setup
  • Takes the drivers right to thermal rating
  • Setup gain structure so that clip lights never/barely come on
  • Know your gettting everything out of the drivers and not overdriving them
  • Sit back and enjoy

agree the 6000 is better value than the 3000 too.
post #140 of 161
Thread Starter 
Quote:
Originally Posted by NicksHitachi View Post

FWIW, If I were building your setup, I'd use the NU6000DSP.  Run two drivers each channel wired to 8ohms.  Run one channel until you get the other two subs.
  • DSP
  • 1100Wpch RMS= 550W per driver
  • Power limited setup
  • Takes the drivers right to thermal rating
  • Setup gain structure so that clip lights never/barely come on
  • Know your gettting everything out of the drivers and not overdriving them
  • Sit back and enjoy

What benefits do I gain from running the speakers in series to show an 8 ohm load as compared to running them in parallel to show a 2 ohm load. I know an 8 ohm load is easier on the amp itself, but are there any other reasons for doing this?
post #141 of 161
Quote:
Originally Posted by Smigro View Post

What benefits do I gain from running the speakers in series to show an 8 ohm load as compared to running them in parallel to show a 2 ohm load. I know an 8 ohm load is easier on the amp itself, but are there any other reasons for doing this?

Easier on the amp, and it will prevent the drivers from being mechanically overdriven, as in 2 ohm the amp can put out way too much power.
post #142 of 161
and smigro don't worry about that gain stuff. With home theatre stuff from a digital source it' s much, much simpler than what the articles on google will tell you about gain. The article you were reading was for like professional mixing with all different analog sources and stuff. Pretty much just set the amplifier to max, and let audyssey set the sub at the proper level and it's all good. You will never reach your "max" power/driver excursion unless you are turning your receiver way up, like to 0 or +1. If you listen to it that loud then you should be a bit more careful setting your gain, but otherwise it's fine.
post #143 of 161
Thread Starter 
Thanks Boss. I actually saw that Amazon is selling a new iNuke NU6000DSP for like $433. Only $33 more than the 3000 on PE so I may just go that route. My only issue now is I finally found someone selling a matching center channel for my eD[c]12 speakers and really want to get it before they are never to be found again, so that may put this project on hold for a few weeks or so.
post #144 of 161
Quote:
Originally Posted by WagBoss View Post

and smigro don't worry about that gain stuff. With home theatre stuff from a digital source it' s much, much simpler than what the articles on google will tell you about gain. The article you were reading was for like professional mixing with all different analog sources and stuff. Pretty much just set the amplifier to max, and let audyssey set the sub at the proper level and it's all good. You will never reach your "max" power/driver excursion unless you are turning your receiver way up, like to 0 or +1. If you listen to it that loud then you should be a bit more careful setting your gain, but otherwise it's fine.

Sorry bud, but you're wrong here. The HTS link that NH linked to is much more compatible with regards to home theater and should be followed. There is more to gain structure than just letting audyssey knock your signal back down from max after you plug and go. You must take into consideration setting the system up so you can play it to 0, that is reference after all. Then you must take into account the noise floor. With the gains on the amp maxed it may bring up a ground loop hum that wasnt there before. Simply boosting the original signal and dropping the gains on the amp alleviate this. Gain structure should be followed properly, ESPECIALLY by anyone who plans on mixing consumer gear with audio gear.

If it worked out for you to max the gains and go, more power to ya, but for many, it just doesnt work quite like that. \m/ \m/
post #145 of 161
Thread Starter 
Quote:
Originally Posted by beastaudio View Post

Sorry bud, but you're wrong here. The HTS link that NH linked to is much more compatible with regards to home theater and should be followed. There is more to gain structure than just letting audyssey knock your signal back down from max after you plug and go. You must take into consideration setting the system up so you can play it to 0, that is reference after all. Then you must take into account the noise floor. With the gains on the amp maxed it may bring up a ground loop hum that wasnt there before. Simply boosting the original signal and dropping the gains on the amp alleviate this. Gain structure should be followed properly, ESPECIALLY by anyone who plans on mixing consumer gear with audio gear.
If it worked out for you to max the gains and go, more power to ya, but for many, it just doesnt work quite like that. \m/ \m/

The article I think he was referring to was the one I posted, not the one that NH posted. Whether they are the principles or not I am not sure as this is all new to me, but I do know the one I read was different from NH's and quite frankly I am not sure I understood most it. biggrin.gif
post #146 of 161
absolutely, but my point is there are several gain structure for HT threads out there, like the one NH linked to, and gain structure should ALWAYS be followed. If not, it's like racing a speedboat with an anchor in tow, you're never going to get the full potential.
post #147 of 161
Quote:
Originally Posted by beastaudio View Post

Sorry bud, but you're wrong here. The HTS link that NH linked to is much more compatible with regards to home theater and should be followed. There is more to gain structure than just letting audyssey knock your signal back down from max after you plug and go. You must take into consideration setting the system up so you can play it to 0, that is reference after all. Then you must take into account the noise floor. With the gains on the amp maxed it may bring up a ground loop hum that wasnt there before. Simply boosting the original signal and dropping the gains on the amp alleviate this. Gain structure should be followed properly, ESPECIALLY by anyone who plans on mixing consumer gear with audio gear.
If it worked out for you to max the gains and go, more power to ya, but for many, it just doesnt work quite like that. \m/ \m/

That article is good. I was talking about the one that smigro linked.

This is all you really need to know from the article smigro:

"You can use either analog L/R connections between the DVD player and the AVR, or a digital connection, but the latter is generally preferable. Don’t forget to change the speaker setting in the AVR’s menu to “Large.” Set the receiver to “Bypass” or “Stereo” mode if you want to measure the main left or right channels, or to “Dolby Pro Logic” if you want to measure the center channel.

We’re ready to proceed. My AVR has all speaker-level settings referenced to the main left and right channels, which are fixed and cannot be adjusted in the menu. If your AVR allows for adjustments for the front left and right channels, they should be set to maximum for this exercise, as should the center channel and subwoofer if you intend to measure those too. In addition, make sure any auto-EQ functions are disabled and/or tone controls are adjusted to flat (0 dB gain).

After setting the output levels, unplug all speakers from the AVR! Once that is done you can start the test disc, turn the AVR’s volume all the way up, and measure the output for the desired channel with the VOM. The meter should be set for low-range AC voltage. The measurement will be taken across the RCA connector’s tip and sleeve. If you don’t have easy rear access to your receiver, an RCA cable plugged into the output you want to measure and routed to where you can get to it is very helpful. It’s easier to take a measurement from a female RCA than a male, so you might want to acquire an RCA coupler before you start."

Subtract 30% from that voltage you measured at maximum volume, and that is your clean voltage. Turn your receiver's volume down to the clean voltage level by looking at the volt meter output. This volume is what you will use to set the pro amp gain.

"To begin, make sure all speakers are disconnected from the amplifiers! Also, make sure all speaker-level settings in the AVR’s menu are set to max, including the subwoofer output. Begin with the amplifiers’ gains all the way down (counter clockwise), and make sure the AVR is set for “Direct,” “Stereo,” “Bypass” mode, etc. – i.e. a straight two-channel signal.

Start the pink noise signal and turn the AVR’s volume control to the setting you previously determined delivered the highest clean (undistorted) signal. (See Part 7 if you’re unsure where that is). Then, increase the amplifier’s gain control until the clipping indicator begins to blink. Keep increasing the gain until the flickering indicator resolves to being lit steady. What we accomplish by setting the amplifier’s gain to clipping with a just-below clipping signal from the pre amp is that both will reach clipping at the same time in actual use. This is the goal of a successful gain structure."
Edited by WagBoss - 8/30/12 at 12:30pm
post #148 of 161
Quote:
Originally Posted by WagBoss View Post

That article is good. I was talking about the one that smigro linked.

Sure enough, but my point remains that for some, cranking the gain to max and letting Audyssey do the rest just doesnt work for several reasons. With my old EPX and LLT's I could do that, but not with my new rig. More often than not, it takes a little more work to get a good gain structure, but as you said, certainly not like the first link that Smigro posted.
post #149 of 161
Thread Starter 
Quote:
Originally Posted by beastaudio View Post

Sure enough, but my point remains that for some, cranking the gain to max and letting Audyssey do the rest just doesnt work for several reasons. With my old EPX and LLT's I could do that, but not with my new rig. More often than not, it takes a little more work to get a good gain structure, but as you said, certainly not like the first link that Smigro posted.

That is good to hear. Like I said earlier the one I read was like trying to understand a foreign language. I will definitely take a look at the on e NH linked. I am hoping that one is a little easier to follow.
post #150 of 161
Wayne is pretty sharp guy too and can answer specific questions you might have along the way, but there are a few of us around here (this guy) who have battled gain structure and won so you have us too smile.gif
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