Post by: Randy Smith on April 22, 2004, 09:51:51 PM
I am courious as to what amp people are using, and if you find one works better than others.
I am sure there are different oppions, but I want to hear them all and why that is your favorite.
Not "Crown xxxxx because it's Crown" or "QSC xxxxx becasuse its QSC".
but like "Crown xxxx because it gives more thump or cleaner etc." this type of post is what I am after --please.
Thanks
Randy
PS. It would also be fun to hear what everyone is using for tops and how many tops and subs you use.
Post by: Brad Litz on April 24, 2004, 12:38:00 AM
Don't believe BS about damping factor. Read this:
http://www.trueaudio.com/post_013.htm
Post by: danfowler on April 24, 2004, 12:41:27 AM
I built my LABs as a "C" rig to go under Mackie 1232's. The reality is one LAB sub will keep up with 2-1232's. This rig has become my favorite for quick strike/setup and having tons of headroom. Doesn't hurt there's a Midas 320 in the mix position.
As for the amps, I started with QSC PLX 3002's bridged mono, 1 per LAB cabinet (3000 watts per box,assumed 4 ohm load). This works really well as there seems to be limitless juice at the amp and the transients are really quick (high cone acceleration, good gamma factor) as the audiophiles would say. This box has some impedance swings and these amps handle them with ease.
There is a Dbx 260 riding herd at the front of all this. Use a good DSP if you power up this strongly. The amp has the 30 hz filter engaged as well as the clip preventer thingie (dip switch). Delay the tops 10 ms. Use 10 ga. wire between the amp and cab. Keep the wire 10' or shorter at this power level. 30 hurts! Yes, what a feeling of power, making buildings rattle at will with the 5 string bass.
In the mood for change (as usual for me) I switched these out for Crown Macro VZ-3600's one night. After getting the sensitivities matched on the front end I fired them up for a A-B test. W R O N G!!!!!!!!!!!!!!!!
The 12's bottomed out! No where near the cone control. They did sound a bit more aggressive (that VZ growl) but at high volume levels with kick drum impulses in the mix, they didn't keep the cones happy. This was with the VZ's run mono as well.
Interesting to note, bass guitar and CD's did not bottom them out. Only when I added kick did they protest and loose it. I think 5k's run stereo would be better suited for the application, but since this is a "C" rig and $$$$ matters, I can buy 2 PLX's for what I'd pay for ONE VZ-3600. I just had them sitting idle and wanted to try them that night.
As you may have guessed, the PLX's live happily in the amp rack now. Never more to roam or stray. Happy campers and only 22# each. My back loves it!
To each his own:
Your milage may vary,
Dan O
Post by: PowerSound on April 24, 2004, 07:00:15 AM
I'm using a QSC PLII 236 on 4 Labs (2 a side) with a DBX DriveRack PA as processing. Very clean sound, high transcient.
Putting the 236 sometimes in the clip, and no problems at all. I've also tested 2 QSC PLII 236 on 4 labs (1 a side) and it sounds "cleaner" and louder. I'll try some PLII 236 bridged on the labs...
Post by: Jon McDowell on April 26, 2004, 02:43:14 PM
The results:
the PL9.0; was tighter and had more "throw" (also blew a breaker)
the 2 PL4.0's; not quite as loud or tight, but still very impressive
the single PL4.0; almost insignificant difference from 2 PL4.0's
Also tried 2 labs powered by 2 PL4.0's V.S. 4 labs by 1 PL4.0.
The 4 labs had way more output.
These boxes work great with as little as 1000W/box. If you need more volume, I would suggest more boxes before more power.
Just my $.02
Good luck.........Jon McDowell
Post by: Tamas Tako on April 27, 2004, 04:20:57 AM
1 Lab with 1 side of both CROWN MA5000 and LABgruppen fP6400. ca. the same results.
The QSC PL4.0 sounds better but less power- less SPL.
Now I will try the CREST V1500 in bridge for 1 lab becouse I have a lot from those amps and I didn't use them for a long time...
Cheers,
TT
Post by: Tom Herr on April 27, 2004, 04:27:10 PM
I am seriously considering for weight, AC Power, and rack space changing to QSC's PL6 1 for 4 Labhorns. Seems to be a fairly decent match. Especially since the PL9 has been nixxed.
For tops I run Yorkville Elites EF508's one to one and I have been pretty happy with the results. I tried running them two to one but the Yorkies were just coasting along.
I would like to hear some Unity 2-15's with the Labhorns.
Post by: Al Limberg on April 28, 2004, 01:49:17 AM
I mixed a show last week in a clun with a pair of my Labs and a pair of TD-1s (long and narrow room). One on one it was a pretty good match. The rig was running 3 PL3402s - 2 bridged for the Labs and one in stereo for the TD-1s. Only real problem was keeping the TD-1s from 'walking' on top of the Labs - they are finished in the Linex paint and no feet - yikes!! I haven't tried the Unity 115s yet but a friend ran the same rig in the same room with the only exception being a pair of Unitys but he wasn't real happy with his results. (Then again he didn't delay the tops to the subs at all and I wasn't there so I am in no way lending credence to his report). If I get a chance to run some Unitys and Smaart the rig I'll post my impressions.
Al
Post by: Tom Herr on April 29, 2004, 09:25:31 AM
Been a while since we last talked.
I look forward to your review.
I wish I was in a position to buy some TD1's but I am making preparations to build a new shop. Just purchased a few acres out in the sticks and am trying to get some trees cleared out so I can start construction.
Between running a chain saw, cab orders, shows, sales, and the day job, time seems to be on the short side. And all incoming cash is going towards the new shop. I guess outgrowing my current shop is a good problem to have so I'm not complaining. But it is frustrating knowing that I need to upgrade parts of my system but have to throw all my finances at the new building. Building line arrays in a 30 X 40 shop is a bit tight. Wouldn't be so bad if I didn't need a table saw, router, air-compressor, dust collector, sander, drill press, assemby table, clamps, etc.
Tom
Post by: Alan Star on November 23, 2006, 04:18:41 AM
I run 2 labhorns per channel in parallel.
It may be interesting to note that on the front display of the iTech the monitor feature shows a loading of 3 ohms per channel in the above configuration. Sometimes it will flash to 2 but mostly says 3... for what it's worth.
If I could afford another iTech I think i would get another and run one box per channel.
Post by: Phil Pope on November 24, 2006, 07:28:55 AM
Phil
Post by: Josh Billings on November 26, 2006, 09:16:45 AM
-Josh Billings
Post by: Kit Hannah on December 06, 2006, 05:59:37 PM
| Alan Star wrote on Thu, 23 November 2006 01:18 |
Crown iTech 6000 I run 2 labhorns per channel in parallel. It may be interesting to note that on the front display of the iTech the monitor feature shows a loading of 3 ohms per channel in the above configuration. Sometimes it will flash to 2 but mostly says 3... for what it's worth. If I could afford another iTech I think i would get another and run one box per channel. |
Maybe the amp is showing 3 ohms because you have 2x 6 ohm labs run in parallel? Just a thought...
Post by: Kit Hannah on December 06, 2006, 06:10:30 PM
I saw a lot of people have been reccomending the PL 6.0's. Anybody using any other powerlights or PL2's to power? Are you bridging or running stereo?
Thanks
Post by: Ivan Beaver on December 06, 2006, 06:28:45 PM
Now if you were clipping the amps and thinking that they were wired in parallel, then there is a different type of confusion and you deserve the blown drivers. Sorry.
And before you blame the amps you have to determine the REAL cause of the reason the loudspeakers no longer work, there could be other issues that caused them to break-not necessarily "blow" from the power that is applied to them
Post by: Mac Kerr on December 06, 2006, 06:30:09 PM
| Kit Hannah wrote on Wed, 06 December 2006 18:10 |
We're trading in the crowns for some Powerlights. Tired of the weight, and come to find out today that they blew up 4 of our 8 labs. (Dual hornlodaded lab cabs). We just realized today that the barebone cabinets we purchased last year were wired in series, not parallel. I guess we assumed it was fine. It's a sperate access pannel to see the wiring, plus everything is coverd by shrinkwrap. never had any reason to look, finally did today. Looks like we might have been significantly under powering them, causing 4 labs to blow - and it was random, so it looks like some of the labs held up, some didn't. Sucks, but it happens. |
I wouldn't expect the driver to operate as intended in the wrong box, but being wired in series shouldn't have been a problem unless the speakers were not wired with the plus of one to the minus of the other. Properly wired, so the drivers moved together, the only downside would be less power to each driver. If the drivers were out of polarity with each other they would just tear each other up with not much sound coming out.
Mac
Post by: Silas Pradetto on December 06, 2006, 08:50:47 PM
I love the built in DSP on the Itechs, along with the diagnostics and remote control. Some people like it, some don't.
Post by: Mac Kerr on December 06, 2006, 09:04:29 PM
Mac
Post by: Kit Hannah on December 07, 2006, 01:59:16 AM
| Ivan Beaver wrote on Wed, 06 December 2006 15:28 |
It would not have been the underpowering that blew them. If you are simply thinking that the amps would not deliver the rated power to them, then you are confused with the whole "underpowering issue". The reason that underpowering is blamed for "blowing" loudspeakers is when you run the amp into clipping, and that is what is blowing them-not the actual power. If you run less than rated power to a speaker that is a very good thing, as long as you do not clip it. Now if you were clipping the amps and thinking that they were wired in parallel, then there is a different type of confusion and you deserve the blown drivers. Sorry. And before you blame the amps you have to determine the REAL cause of the reason the loudspeakers no longer work, there could be other issues that caused them to break-not necessarily "blow" from the power that is applied to them |
Okay, thanks for jumping all over me guys.
I am well aware of amplifier power and the effect it has on drivers. When I use the term "blown", I'm saying they are no longer working - not even passing a signal with the ol Multimeter. Yes, distortion (clipping) is what will kill the driver - well aware of that guys.
As far as saying that I deserve the blown drivers - maybe and maybe not, but that's a little harsh. The terminals were wired improperly, combining 2+ and 1-, then switching it went it jumped to the second NL4. They were not all like this, and that is why some of the cabinets are still working just fine. We purchased the cabinets complete but unloaded, and were told that everything was run parallel. They were half right. We spent some time rewiring the cabs so that they were properly run parallel.
The cabinets were not designed for the lab subs - we knew this from the beginning. The picture in my earlier post is of the dual 12" horn loaded sub cabinets we use - Thats what I mean by that. 2x 12's, one cabinet, horn loaded. We decided on the Labs because of the specs and reviews, and another guy who had an identical system was doing the same thing and raving about them. We know they were designed for a certain cabinet, but wanted to take our chances to see what they were all about. We think it paid off, as they put out an extreme amount of lows. Even after tonight's show, with only 4 working, we were still impressed. We have had the system now for about a year and a half, and nothing but compliments.
We are not calling this a lab box, Ivan. We call them subs like everyone else and they just happen to have labs in them. They truly sound great and produce earth shaking, ceiling tile falling bass. We have not compared them to any of the boxes specifically designed for the lab, but we figure in this particular cabinet that matches the rest of our system, we might as well put in a driver that moves some air.
The amps really are fine (MT2400's), but we would just prefer to have some newer technology, something lighter, and something with a ton more power so we can have the added headroom. Taking off some weight will help too.
We're happy with our system, and all of our clients love it. Very versatile, yet compact, loud and reliable. Like mentioned above and earlier, We're looking at powerlights, but if anyone has any other suggestions for amps to power labs, please feel free to weigh in, as that was what the post was originally about.
Thanks
Post by: Jon McDowell on December 07, 2006, 09:36:20 AM
Another (easily entertained) $.02
Jon
Post by: Alan Star on December 07, 2006, 10:15:35 PM
| Kit Hannah wrote on Thu, 07 December 2006 07:59 | ||
Maybe the amp is showing 3 ohms because you have 2x 6 ohm labs run in parallel? Just a thought... |
Well actually...no...because if you read my post you will see that i am running 2 labhorns on each channel and each labhorn has 2 6ohm drivers...so actually thats 4x 6ohm drivers in parallel on each channel which is why I find it interesting that the itech sees a 3ohm load on each channel ? Sometimes it will flicker down to 2 ohms...I wonder how accurate it is ?
Post by: Mac Kerr on December 07, 2006, 10:26:58 PM
Mac
Post by: Sean Tan on December 17, 2006, 12:05:48 AM
Been lurking around here for quite a while, planning to build a couple of Labs next year.
One thing thats been bothering me is how to go about powering them. Many people report bridging one amp per LABsub, with good results. To my understanding, one Lab has two 6ohm drivers wired in parallel, presenting the amp with a 3ohm load, nominally rated.
My question is, if the amp is running a 3ohm load while bridged, wouldn't each channel "see" half that impedance (1.5ohms)? Correct me if I'm wrong, but isnt that load below what most amplifiers are designed to drive?
Cheers
Sean
Post by: Tom Herr on December 18, 2006, 06:22:23 AM
As for the amps I have powered mine with QSC, RMX and PLX's Bridged one per lab with no problems. I think you will find many others here who have had similar experiences with various amps.
Hope this helps.
Post by: sheldon harris on December 26, 2006, 10:07:55 AM
| Sean Tan wrote on Sun, 17 December 2006 01:05 |
Hi all, Been lurking around here for quite a while, planning to build a couple of Labs next year. One thing thats been bothering me is how to go about powering them. Many people report bridging one amp per LABsub, with good results. To my understanding, one Lab has two 6ohm drivers wired in parallel, presenting the amp with a 3ohm load, nominally rated. My question is, if the amp is running a 3ohm load while bridged, wouldn't each channel "see" half that impedance (1.5ohms)? Correct me if I'm wrong, but isnt that load below what most amplifiers are designed to drive? Cheers Sean |
the amplifiers would not see 1.5 ohm unless the cabinet is driven below its cutoff frequency. even if driven below F3, the impedance might be lower or higher than 3 ohms, and is frequency dependent.the reason why people are bridging amplifiers per labs is that:
a properly designed horn loaded enclosure, will load the drivers, so that they typically exhibit(amplifier sees) an impedance of 1.5 to 2 times the nominal impedance. example:
a 4 ohm speaker in a properly designed horn enclosure would behave as if its a 6- 8 ohm speaker. this is the tricky part, the dc resistance is not changed by the horn's loading, and the rule only applies, if the driver/horn is driven in its passband above cutoff frequency. if the horn driver/horn is driven with frequencies near or approaching F3 that phenomenon begins to change slightly as excursion increases and the horn more and more begins to lose control of the cone. below F3, the loading has been lost and the driver will revert back to its original impedance because there would be no horn loading.
I'm pretty sure someone else can add to what i have said, when it comes to horn technology this site has quite a few members who are the "authority" so to speak.
Post by: jeffhtg (Jeff Kenney) on November 03, 2008, 10:17:00 PM
I'm pulling all cabinets this winter to inspect them carefully - seal any holes I find and play with powering them a little more.. My thoughts are that the the subs could use a little more power and the cheaper RMX amps are just not providing the same control that the VZ's are. (even though I usually like QSC over Crown for audio quality)
Post by: Mac Kerr on November 04, 2008, 09:41:41 AM
| jeffhtg (Jeff Kenney) wrote on Mon, 03 November 2008 22:17 |
So I've been running 8 labs for few years now. |
If you have been running these for a few years now, why didn't you answer this question in April of 2004 when it got asked? Even the recycling of this question was 2 years ago. Why dredge it up a third time?
Mac
Post by: jeffhtg (Jeff Kenney) on November 05, 2008, 08:48:14 PM
| Mac Kerr wrote on Tue, 04 November 2008 14:41 | ||
If you have been running these for a few years now, why didn't you answer this question in April of 2004 when it got asked? Even the recycling of this question was 2 years ago. Why dredge it up a third time? Mac |
slow news day mac..
Post by: Dave Yorke on September 23, 2009, 09:53:13 AM
so far no problems with the subs, due to limiting.
Post by: Silas Pradetto on September 24, 2009, 05:37:54 PM
| Dave Yorke wrote on Wed, 23 September 2009 09:53 |
FFA 8.0 - 2 labs per channel. sounds bloody amazing... lightweight and clear. we own 8 subs in all but i need another amp. so far no problems with the subs, due to limiting. |
Prepare for Mac's wrath...
Post by: Eric Hassler on September 24, 2009, 06:54:40 PM
| Silas Pradetto wrote on Thu, 24 September 2009 16:37 | ||
Prepare for Mac's wrath... |
I understand it's an old thread, but isn't this information still useful? What's worse, starting a new thread to talk about the same info, or bumping an old thread to add some info? I guess it's a matter of opinion.
Post by: Silas Pradetto on September 24, 2009, 10:29:45 PM
| Eric Hassler wrote on Thu, 24 September 2009 18:54 | ||||
I understand it's an old thread, but isn't this information still useful? What's worse, starting a new thread to talk about the same info, or bumping an old thread to add some info? I guess it's a matter of opinion. |
It'd be far more useful if I knew what an FFA 8.0 was...
(google isn't helping this time)
Post by: Eric Hassler on September 24, 2009, 11:45:55 PM
| Silas Pradetto wrote on Thu, 24 September 2009 21:29 | ||||||
It'd be far more useful if I knew what an FFA 8.0 was... (google isn't helping this time) |
I did a bit of searching and found this:
http://www.noisecontrolaudio.com/products_ffa5000.html
Post by: Silas Pradetto on September 25, 2009, 12:13:01 AM
| Eric Hassler wrote on Thu, 24 September 2009 23:45 | ||||||||
I did a bit of searching and found this: http://www.noisecontrolaudio.com/products_ffa5000.html |
Well I'm glad I wasn't missing anything...
Post by: TrevorMilburn on September 25, 2009, 05:57:21 AM
http://www.fullfataudio.com/
Regards,
Trevor
Post by: Eric Hassler on September 25, 2009, 10:33:20 PM
| Silas Pradetto wrote on Thu, 24 September 2009 23:13 | ||||||||||
Well I'm glad I wasn't missing anything... |
My mistake. I found the link on another forum discussing the FFA 8.0 and thought it was the same amp. That's what I get for posting when I'm exhausted!
Post by: Dave Yorke on October 02, 2009, 06:54:22 AM
We have an 8 - 4K per channel and a 6 - 3K per channel.
There is a psu per channel and they are comfortable being ragged at 2 Ohms. The 3600 has one psu.
sorry, should have mentioned before.