or Connect
AVS › AVS Forum › Audio › DIY Speakers and Subs › 8x 18" LMS Ultra 5400s in 4 sealed enclosures
New Posts  All Forums:Forum Nav:

8x 18" LMS Ultra 5400s in 4 sealed enclosures - Page 10

post #271 of 525
That is awesome, is the mic at the LP, and if so how far away is it? So how many watts does that bring u up to? AMAZING!
post #272 of 525
Thread Starter 
That's with the mic at the LP which is 12-13' from the subs. There are four Marathon MA-5050s powering this setup. The previous measurements were with two amps.
post #273 of 525
Quote:
Originally Posted by notnyt View Post

There is no need for this in a sealed enclosure. Vented/PR enclosures will require this.

We should clarify that its not needed in a sealed design if that design is <= X cuft (I forget what X was).
post #274 of 525
Thread Starter 
Quote:
Originally Posted by penngray View Post

We should clarify that its not needed in a sealed design if that design is >= X cuft (I forget what X was).

I think you mean <=
post #275 of 525
Edited

Great distortion measurements, incredible SPL there!!!
post #276 of 525
At your normal listening level what do you hit as far as peaks with program material?

I am thinking of the normal suspects, WOTW, Master and Commander...., The Irene scene in Blackhawk down would be of interest also.

The peaks you are getting would be as clean as it gets.
post #277 of 525
Quote:
Originally Posted by vitaminbass View Post

I use stainless wire (it's actually safety wire for racing) strung through two holes on one side of the basket, and two on the other, makes a "handle" on each side. Then I use heavy leather gloves so the wire doesn't cut into my hand. Once the driver is set in place the wire is slippery enough you can just pull it out and you are set to go.

you guys are nuts, i still have envy of my cute little 1803's
post #278 of 525
Quote:
Originally Posted by notnyt View Post

I think I was starting to hit the limits of my mic here. I only measured from 20hz since my amps will protect at this level if I send DC.



I get it
post #279 of 525
Notnyt,

Once again, nice build. Your new numbers have got me thinking. I know you're using some custom SS control for amp power, but I've got a couple questions regarding the high current/stable voltage delivery for your rig. I've mentally put some details together from a mixture of things you've posted at different times. Correct me wherever I go wrong; Each amp on it's own dedicated circuit. Is it 20a breaker, 10awg wire, 20a receptacle? I'm interested in all the details if you could furnish them. Breaker size, location, wire sizes, distances etc. Also, have you monitored voltage and current levels during heavy draw periods?

I believe you stated 10awg wire size was used, but what type of plug strip are you referring to that tripped? I've seen power strips exhibit current limiting characteristics, which in turn cause voltage drop that may result in subsequent nuisance tripping. We find ourselves in an environment whereby some plate amps are limited by wall power, and full size outboard amps (like those arc welders you've got) can be extremely demanding on all up-stream components. I can tell you're aware of this, it's just not that often that a rig really has the capability to tax an electrical system.

I'm curious about your SS relay system, and its current handling capability. Obviously, sitting in your room enjoying eight of the finest LF drivers in the world, there isn't any problem. But from afar, as I enjoy reading your component list, it would seem the relay system, really jumps out as a potential weak point in assuring a low loss, high current delivery to your amps. It's certainly a nice slick way to remote the power for the amps, that's for sure. However, I'd be too concerned about potential losses incurred and current limiting from running amplifier line voltage through that device.

No disrespect. This is an epic sub build that elicited the best line I've read in a thread in a long time. "The Maels got China Syndrome and my man just pushes the balls button to git 'er done." That alone made the entire thing worthwhile for me. Having decades of being around show business, the electrical trade, and of course live pro audio, I've seen electrical failures in nearly every conceivable scenario. From high voltage switchgear explosions and melt-down, to simple receptacles overheating. The vast majority of failures I've been witness to are related to the inability to thermally dissipate in an adequate manner. Oftentimes, this is exacerbated by a very slight amount of added resistance at a connection. I don't think you're in any danger of failure, hell SS relays typically fail closed.

The use of the SS relay in general, doesn't seem like a good idea even in the best operational conditions. When examining the theoretical aspects of the circuit, it exhibits voltage drop and ohmic characteristics that are significant and lossy relative to a hardwired connection. This to me, when considering the entirety of your no compromise, reference quality LF build, seems to be a choke point. However, correct me if I'm wrong.

The Omron device, when ideally heat sinked is rated for 20 amps. Without proper heat sinking, 5 amps. When viewing your photos, it appears to me that the device stands off the inside edge of the 4" square box, due to the adjacent knock-outs being raised. How much does this contribute to proper heat sinking? However much percentage wise this mounting method deviates from the spec of fully heat sinked, that's how much less than optimum the theoretical thermal capability is lessened. Also, I'd think that amp can easily exceed the 20 amp rated limit of the relay triac under some circumstances. The QSC amp, that is the purported model for the Marathon 5050, is also a class H, 5kw design. The QSC 5050 draws 27 amps at 1/3 power pink noise, at 4 ohms, with the ability to draw even more. It's well understood that breakers can easily allow several seconds of many times their rated over-current trip amount to pass without interruption. So the relay triac you're using, and it's limited capacity that's dependent on heat-sinking, clearly appears to be a potential bottleneck. Inherent to all SSRs is a voltage drop during conduction, and a subsequent requirement for heat dissipation.

From an SSR OEM website;
"Solid state relays have no moving parts so there is no mechanical reason why they should fail. However, traditional solid state relays (and other modern electronics) may be damaged by three local installation reasons -- over voltage power surges, over current due to inrush or improper fusing, and over temperature due to poor thermal dissipation. If you plan for these three situations, you will remove the vast majority of solid state relay failures."
Failure, isn't a big deal, because as I stated, they normally fail closed,..so no biggie. I'm curious if you feel that there may anything to my theory about current limiting.

This build in general, and your sub rig more specifically, will be quite the reference in discussion here at AVS, and elsewhere for some time. Hell, it already started. There is references all over AVS to this build. Your room is kick ass too. The ~25 foot width is just great, and so conducive good lateral characteristics, and lessen problematic sidewall interactions. It just all adds up to a kick ass combination.

Anyway, I'm curious if you've given much consideration to this. Those relays do possess enough voltage drop and power consumption that on peaks, they'd hit 30 watts or more. It doesn't seem like much, and it isn't really, but when a single pole switch could do the job with no voltage drop and current limiting, I would go with the switch. Or just use the front panel switch. IMO, it just sticks out in an otherwise balls out build.

Killer build, and those measurments are, uh, solid There will be references to this for quite some time.



Thanks
post #280 of 525
Thread Starter 
200a service to the house, 10awg runs to nema 20r outlets off of 20a breakers. There is about 30-50ft of wire depending on the circuit, as they're spread along the back wall.

In each outlet, I have a Cyberpower CPS-1220RMS PDU rackmount power strip and surge protecter. I was previously using Belkin 15a power strips, which is obviously a problem. Since all of my gear is interconnected, I wanted to make sure they were all run through surge protection. From there, I have my SS relay box hooked up. The relays are mounted to the box, and to ensure heat transfer, I used a bit of thermal paste on the bottoms. I've had a Kill-a-watt hooked up to them, and have seen the amps pull over 2900w before the PDUs tripped. Keep in mind the MA-5050s are fused at 20a, though I have not seen one pop yet.

Update:

I just did some testing with a kill-a-watt before and after the relay. If I push the amp to clipping with a 10hz sine wave, it is pulling between 2300-2400 watts. I don't really see any difference before or after the relay box. Also, it is REALLY hard to take a picture of a Kill-a-watt at those levels, as the display is flashing quite a bit. When I saw the higher levels, it was during WOTW 5hz scene and I was trying to diagnose why my surge protectors were tripping. After running 10hz test tones at 2400w for over a minute, the boxes are definitely warm and doing their job sinking up the heat. That is why I used metal boxes and thermal paste. If they got this warm under normal load, I would worry a little bit, but this kind of abuse will never happen in real situations.

In voltage mode, it was reading 127v under full load, 120v at no load. This was measured before and after the relay, no difference.

At idle, the amps take between 63-67w depending on how warm they are.

Amp at idle:


Clipping the amp at 10hz:
post #281 of 525
It really is probably a non-issue but I agree with FOH. It is better to skip using surge protectors or power strips with big pro-amps. Most of them are a bottleneck under some scenarios unless they are really beefy like those for industrial applications.
post #282 of 525
Thread Starter 
Hence why I'm using cyberpower rackmount pdus

They trip around 2900w of continuous power. No bottle necks here really. These are designed to have a LOT of power run through them. 20a breaker and 20a fuse in the marathons, and this setup can continuously pull that, so I'd rather have the protection than not. Just remember, all this stuff is connected. If you get a surge, it can go through your entire system.


post #283 of 525
What the hell must almost 130db at 10hz feel like. Did you wear ear plugs cos that must have been one experience.
post #284 of 525
Quote:
Originally Posted by notnyt View Post

New power strips (rackmount PDUs actually) and double the amps


I think I was starting to hit the limits of my mic here. I only measured from 20hz since my amps will protect at this level if I send DC.

My turn? David and Goliath, but ok. fine. WHATEVER! Working on it now. Then I'll attempt to plug my ports and then REALLY get stomped on. recomendation on most effective way to quickly plug/unplug 12" ports without damage or alteration? Simple pillow prolly not very effective. cuts arent perfect, lid/cap prolly a no-go.
post #285 of 525
Thread Starter 
don't bother plugging, just see what you have. It's not really a competition, I'm just goading you into taking measurements and learning REW
post #286 of 525
well it's working
Im curious what she would do sealed up, though I know I'd need to EQ
I'm having a lot of fun and learning so much so fast (well, maybe Im learning a little while being presented with a ton?)
so thank you ver much notnyt!
post #287 of 525
Quote:
Originally Posted by notnyt View Post
Hence why I'm using cyberpower rackmount pdus
Do you use one per amp?
post #288 of 525
Thread Starter 
Quote:
Originally Posted by penngray View Post
Do you use one per amp?
yes
post #289 of 525
Thread Starter 
I just picked up four boxes of OC703 today. Going to build some corner traps. Should even out some of the dips that occur at different places in the room a bit. Lot of OC703 up in here
post #290 of 525
How did you get the graph and numbers to show? I took some measurements but it is just a graph, no numbers. I am going to run just one sub to give me an idea what one can do because my soundcard will not go high enough.
post #291 of 525
Just curious to know what you reckon the max spl figures would be on this set up.
post #292 of 525
Quote:
Originally Posted by MKtheater View Post

How did you get the graph and numbers to show? I took some measurements but it is just a graph, no numbers. I am going to run just one sub to give me an idea what one can do because my soundcard will not go high enough.

windows snipper
post #293 of 525
NYT,

Since you are going to add some bass traps, can you grab some before and after waterfalls? Thanks.

James
post #294 of 525
Thread Starter 
Of course. I'm trying to figure out how to put mounts up on the wall and have them covered and still looking pretty.

post #295 of 525
Thread Starter 


post #296 of 525
Thread Starter 
before and after without even re-running audyssey yet.

post #297 of 525
I could use some of that insulation right now
post #298 of 525
Quote:
Originally Posted by notnyt View Post

before and after without even re-running audyssey yet.


Insane. I'm going to have to build some cornertraps.
post #299 of 525
Quote:
Originally Posted by notnyt View Post

Of course. I'm trying to figure out how to put mounts up on the wall and have them covered and still looking pretty.

I cut fabric a few inches wider than the traps. Then I stapled each side of the fabric to the inside of 1" outside corner molding. I placed the molding on one side of the traps and nailed it with a brad nailer. If you put both legs of the molding against the wall it creates a 45 degree angle and works well. I used a fabric that matched the wall color and it blends in well. I also didn't worry about nailing into studs. Some of the molding is nailed right into the drywall.

post #300 of 525
Thread Starter 
I'm going to put some 1x2's up on the sides of it and frame it out. Then I will staple fabric to the sides of the 1x2 and put a piece of trim up to cover the staples. I would have done it already but I want 8' lumber and the only leftovers I had in the garage were 6'.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: DIY Speakers and Subs
AVS › AVS Forum › Audio › DIY Speakers and Subs › 8x 18" LMS Ultra 5400s in 4 sealed enclosures