You're going to be grinning like a cheshire cat when you hear them light up.......
I was for a couple of days when mine were finished.😀
Rob.
I was for a couple of days when mine were finished.😀
Rob.
Re: pics, finally:
Remember to turn the subharmonic synthesizer 'on'. Then when somebody complains about the bass from four miles away you'll really have cause for that cheshire cat grin.
boukisan said:
Remember to turn the subharmonic synthesizer 'on'. Then when somebody complains about the bass from four miles away you'll really have cause for that cheshire cat grin.
wg_ski said:
Don't need any excuses - they're in my living room and everything goes through them everyday. 😀
Rob.
They're temporarily wired parallel outside the back of the cabinets until I get the stuff to make the speakon cables. Also want to be sure that I have them wired correctly before I make this permanent.
I am still not completely sure about the wiring. I must confess that the only skill I've brought to this project is woodworking. (Here is where I remember DJK telling me several months ago that I shouldn't even bother making these speakers.)
I am assuming that for two labhorns: all of the negative posts on the four drivers go to one negative line, and all the positive posts on those four drivers go into one positive line so that two LABs are seen as one speaker with all parallel. I may have misinterpreted the diagram that I was given. Does this sound right?
I am still not completely sure about the wiring. I must confess that the only skill I've brought to this project is woodworking. (Here is where I remember DJK telling me several months ago that I shouldn't even bother making these speakers.)
I am assuming that for two labhorns: all of the negative posts on the four drivers go to one negative line, and all the positive posts on those four drivers go into one positive line so that two LABs are seen as one speaker with all parallel. I may have misinterpreted the diagram that I was given. Does this sound right?
Don't sound right to me..
Don't know which qsc amp you have, but I'd run each labhorn off its own channel on the amp. I'd parallel the drivers inside the labs.
Rob.
Those flare panels are fun ain't they ?😀
Don't know which qsc amp you have, but I'd run each labhorn off its own channel on the amp. I'd parallel the drivers inside the labs.
Rob.
Those flare panels are fun ain't they ?😀
BTW:
With casters on the back and heavy duty handles, two on top and two on bottom, it's VERY easy to tilt it up on two wheels and roll it around without any assistance. Also easy to lower it down onto all four wheels and move it around that way, although two wheels makes for easier steering, and you can leverage it up into an elevated doorway.
I put some 3/4" thick rubber feet on the bottom, which really helps the box to grip the ground when you're tilting it back. It's still heavy enough to be a little stressful moving them around, but I've moved them through the whole process with no trouble at all...
The main thing that I learned with the first box is to attach the heavy-duty t-nuts to the back panel before you even start to assemble the pieces for the outside of the box. Using epoxy before hammering them in (being careful not to get it into the threads) assures that you won't have any pop-outs. There is no combination of curse-words that can express the level of frustration that comes from a t-nut losing its grip. Epoxy and you'll never deal with it again.
With casters on the back and heavy duty handles, two on top and two on bottom, it's VERY easy to tilt it up on two wheels and roll it around without any assistance. Also easy to lower it down onto all four wheels and move it around that way, although two wheels makes for easier steering, and you can leverage it up into an elevated doorway.
I put some 3/4" thick rubber feet on the bottom, which really helps the box to grip the ground when you're tilting it back. It's still heavy enough to be a little stressful moving them around, but I've moved them through the whole process with no trouble at all...
The main thing that I learned with the first box is to attach the heavy-duty t-nuts to the back panel before you even start to assemble the pieces for the outside of the box. Using epoxy before hammering them in (being careful not to get it into the threads) assures that you won't have any pop-outs. There is no combination of curse-words that can express the level of frustration that comes from a t-nut losing its grip. Epoxy and you'll never deal with it again.
I'll dig up the final word that I got on the lab forums for wiring them. Maybe I can get a different explaination here..
The flare panels were fun, assuming you mean "using the wood that I thought I would have leftover - fun", right? Also known as "really should have considered getting this all CNC'd, fun."
The flare panels were fun, assuming you mean "using the wood that I thought I would have leftover - fun", right? Also known as "really should have considered getting this all CNC'd, fun."
Going by that thread, do you think all parallel will work, wiring them down to two cabinets per channel? Also is my interpretation of parallel correct?
all 4 negative posts wired into one + all 4 positive posts wired into one = 1 channel
all 4 negative posts wired into one + all 4 positive posts wired into one = 1 channel
This is how I have them wired now. Parallel, in phase so that they are firing towards each other.
This results in basic impedance of 1.5 ohms, but I have been told on other forums that when you add up mechanical impedance and a few other factors they come in right below 4 ohms, which is what my QSC is rated for: 2500 watts per channel at 4 ohms, giving each labhorn 1250 watts.
This results in basic impedance of 1.5 ohms, but I have been told on other forums that when you add up mechanical impedance and a few other factors they come in right below 4 ohms, which is what my QSC is rated for: 2500 watts per channel at 4 ohms, giving each labhorn 1250 watts.
Hi Bouki,
if your amp is rated to 2500W into 4ohms then it will push >=1250W into each 8ohm cabinet.
If you run both cabinets at 3 or 4ohms and then parallel them you risk overloading your amplifier.
Each cab wired as an 8ohm (series) can be safely driven by your 2500W into 4ohm amp.
If you want, you can run a pair of 8ohm cabs off the amp. I prefer to dedicate one amp to one cab.
Buy a pair of 4pole Speakon sockets and cable plugs.
Bring each driver out to the Speakon sockets.
That gives you the greatest flexibility in amp connections. Either series or parallel and using anywhere between 1amplifier upto 4amplifiers.
if your amp is rated to 2500W into 4ohms then it will push >=1250W into each 8ohm cabinet.
If you run both cabinets at 3 or 4ohms and then parallel them you risk overloading your amplifier.
Each cab wired as an 8ohm (series) can be safely driven by your 2500W into 4ohm amp.
If you want, you can run a pair of 8ohm cabs off the amp. I prefer to dedicate one amp to one cab.
Buy a pair of 4pole Speakon sockets and cable plugs.
Bring each driver out to the Speakon sockets.
That gives you the greatest flexibility in amp connections. Either series or parallel and using anywhere between 1amplifier upto 4amplifiers.
I've got testimonies from several seasoned users of Labhorns that wouldn't agree with that statement. They're all over the LAB forum, but here's a typical response:
"I've been running mine 2 boxes per channel off of QSC Powerlight 9.0's. That's 2250w per box, or 1125w per driver. We've done some SERIOUSLY loud shows with this setup, and have only occasionally seen -10 lights on the amps. Usually they get run in blocks of 4 or more (usually 8 ) in this configuration. The only way I've killed them is with bad air seals on the rear chambers."
"I've been running mine 2 boxes per channel off of QSC Powerlight 9.0's. That's 2250w per box, or 1125w per driver. We've done some SERIOUSLY loud shows with this setup, and have only occasionally seen -10 lights on the amps. Usually they get run in blocks of 4 or more (usually 8 ) in this configuration. The only way I've killed them is with bad air seals on the rear chambers."
those lab12 look totally awesome, makes me want to build something now 😀
what speaker coating did you refer to in post 17?
what speaker coating did you refer to in post 17?
AndrewT said:
This is true for run-of-the-mill sealed or vented alignments, but compression horns whether designed to be run alone or multiple stacked (four minimum in the LAB's case IIRC) are acoustically loaded to the point of raising the summed impedance considerably in its passband, so as long as the drivers are high passed to protect them below ~0.707x its impedance peak the amp should 'feel' a minimum impedance much higher than the simple paralleling resistances calc implies.
Anyway, I recommend measuring the stack's impedance wired in parallel to find its passband amp loading and high pass point rather than trusting any testimonial.
There's still the issue of how much power the driver can heat-sink though and here too the increased acoustic loading makes the driver require considerably less current than predicted, though short of doing destruction testing to find your stack's power limit you'll have to trust the testimonials.
As always though, YMMV.
GM
DURATEX speaker coating
Duratex speaker coating comes in roll-on or (hopper) spray form. You can buy 1 gal, 5 gal or 55 gal drums of it. It dries quick. To make it go further and adhere better, I did a base coat of flat black latex paint, let that dry for 24 hours, then covered it with two coats of duratex using open foam rollers.
I did a test board (I was worried about compatibility of finishes) and found that you must wait for the latex to dry for 24 hours, not just to the touch, otherwise they react with each other and crackle, pulling away from the substrate along the tiny cracks.
http://www.acrytech.com/store.asp?pid=14119
Duratex speaker coating comes in roll-on or (hopper) spray form. You can buy 1 gal, 5 gal or 55 gal drums of it. It dries quick. To make it go further and adhere better, I did a base coat of flat black latex paint, let that dry for 24 hours, then covered it with two coats of duratex using open foam rollers.
I did a test board (I was worried about compatibility of finishes) and found that you must wait for the latex to dry for 24 hours, not just to the touch, otherwise they react with each other and crackle, pulling away from the substrate along the tiny cracks.
http://www.acrytech.com/store.asp?pid=14119
2 boxes per channel
It really depends on the amp, with a Lab stack or any other speakers. Any real honest-to-God 2 ohm capable amp will run 2 boxes per channel if they're properly grouped. The Powerlight or PLX 2 ohm amps are fine. RMX2450 or its clones will struggle, and don't even think about it with an old USA series.
It really depends on the amp, with a Lab stack or any other speakers. Any real honest-to-God 2 ohm capable amp will run 2 boxes per channel if they're properly grouped. The Powerlight or PLX 2 ohm amps are fine. RMX2450 or its clones will struggle, and don't even think about it with an old USA series.
- Status
- Not open for further replies.