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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB: The Classic Live Audio Board => Topic started by: Justin Quinn on August 04, 2019, 08:08:35 pm

Title: QSC PLD4.5 vs PL380 on subs
Post by: Justin Quinn on August 04, 2019, 08:08:35 pm
I am looking to power 2 passive SRX828 subs (passive works better for our rig, long story short).  The specs are 4800W Peak, 2400W Program, 1200W rms @ 4 ohms.  I was initially considering running 1 cab per side on a PL380 (2,500 @ 4ohms x 2).  However I noticed the PLD4.5 offers 1,200 watts @ 8 ohms x 4 meaning I could power one driver per channel.  Also I could pick up a new PLD4.5 at about the cost I could pick up a used PL380 (eh, in the ballpark atleast).  I am defiantly looking for a class D solution as where I am often using these I am limited to 120V 20A outlets and they're at a premium.  DSP not a requirement.

Anyone have any experience with the PLD4.5 on subs or in general?  I suppose given the feature set, cost difference, and tendency to slouch off in 2 ohm performance (even though I don't plan on using them in 2 ohms) I am getting the feeling the PLDs aren't a hefty as the PL380s, making the question how much less hefty.  I may also look into a PLD amp for light duty stuff (monitors/fills/etc.)

Thank you in advance.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: scottstephens on August 05, 2019, 10:21:33 am
Justin,

I have never used the PLD series, but if you want subbage you can't beat old school, big power supply amps. It's all about what the amp has in the tank. Don't fall for the 40, 000 watts in a 12 ib package marketing crap.

Scott
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Tim McCulloch on August 05, 2019, 10:43:47 am
My money would be spent on the PL380.  I have no experience with the PLD but it's not designed to be a touring-class power amp, it's designed mostly for fixed installation use.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Corey Scogin on August 05, 2019, 10:52:06 am
I have no experience with the PLD but it's not designed to be a touring-class power amp, it's designed mostly for fixed installation use.

Why do they have a separate CXD installation series if the PLD wasn't meant for touring?
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Mark Wilkinson on August 05, 2019, 10:56:44 am
I use both PLD4.5s and PL380s on subs.  JTR 4 ohm orbitshifters and DIY dual 18"s with 8 ohm drivers each rated 1500W AES. So all 4 ohm loads.
I run the PLDs as 2 Channel Parallel for 2250W into 4 ohm  (2100W into 2 ohm).  The more PLD channels you parallel, the lower the impedance they can drive.  2 ohms is no problem at all once 2 or more channels are paralleled.
All that said, the PL380 is a little more powerful and probably the better sub amp.
However, I'd still choose the PLD just for its multi-use flexibility, DSP, and both peak and rms limiting.
I feel if I'm so close to the edge of using up available power from either amp, I probably need to be thinking more subs instead of more amp.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Mark Wilkinson on August 05, 2019, 11:01:39 am
Why do they have a separate CXD installation series if the PLD wasn't meant for touring?

I agree. 
I have both PLDs and CXDQs.  Different intentions other than the actual amp parts.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Justin Quinn on August 05, 2019, 11:16:06 am
Justin,

I have never used the PLD series, but if you want subbage you can't beat old school, big power supply amps. It's all about what the amp has in the tank. Don't fall for the 40, 000 watts in a 12 ib package marketing crap.

Scott
My skepticism is what brings me.  I would love to carry around some old Macro-techs but I don't think it's worth the back injuries.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Justin Quinn on August 05, 2019, 11:17:39 am
My money would be spent on the PL380.  I have no experience with the PLD but it's not designed to be a touring-class power amp, it's designed mostly for fixed installation use.

Thank you for your input, I figured as such.  It looks like I'm off to find a PL380.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Steve Litscher on August 05, 2019, 12:19:34 pm
+1 for what Tim said. We had PLD4.5s and PL380s, and while I was able to run 2x Orbit Shifters and 2x 3TX on a single PLD4.5 (and it sounded awesome), I'd go with PL380 on the subs, exactly as you have planned (1 cabinet per channel). It'll kick some serious butt.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Dave Garoutte on August 05, 2019, 12:48:07 pm
I have a used one available.
PM me.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Bob Faulkner on August 06, 2019, 07:07:01 am
We have several of the PLD 4.2 amps (lowest wattage amps), which we use primarily for monitors and sometimes for FOH (for the smaller events).

Recently, I used a single PLD 4.2 with one of our SRX728 subs (1600 watts continuous).  All 4 channels of the amp were combined into one (configured to 1600 watts).  The amp did very well... it did not sound like it was struggling.  Even limited to 1600 watts, the bass/kick were always solid.  Though, the amp was sharing the same circuit with some of the event's "mood" lighting.  There were noticeable drops in voltage (from the dimming of the mood lights) when a heavy kick-drum presented itself.

The versatility of these PLD amps is great.  Recallable presets with full DSP.




 
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: justinmquinn on August 06, 2019, 08:31:33 am
We have several of the PLD 4.2 amps (lowest wattage amps), which we use primarily for monitors and sometimes for FOH (for the smaller events).

Recently, I used a single PLD 4.2 with one of our SRX728 subs (1600 watts continuous).  All 4 channels of the amp were combined into one (configured to 1600 watts).  The amp did very well... it did not sound like it was struggling.  Even limited to 1600 watts, the bass/kick were always solid.  Though, the amp was sharing the same circuit with some of the event's "mood" lighting.  There were noticeable drops in voltage (from the dimming of the mood lights) when a heavy kick-drum presented itself.

The versatility of these PLD amps is great.  Recallable presets with full DSP.

Exactly why I think I may want to (also) pick one up for light duty stuff (fills monitors etc.)
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Justin Quinn on August 06, 2019, 09:33:59 am
I feel if I'm so close to the edge of using up available power from either amp, I probably need to be thinking more subs instead of more amp.
I don't think there's such a thing as "too much bass" but the SRX828s are holding me over for now.  I definitely like the SRX828s, they work great for the small and corporate events we currently handle, but they only get so loud so I'm with you on that.  Probably will get better sub boxes and run them off the PL380 when it's time to upgrade.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Brian Jojade on August 09, 2019, 01:15:19 pm
I've got a rack of PLD 4.5's.  The flexibility of the amplifiers is pretty awesome, as you can easily re-configure them for your needs.  My amp rack can be set as a 3 channel system if I want 4500 watts left, right and sub, or up to a 12 channel system if I want to use the amp rack as multiple monitor mixes.

I did have one unit recently give me a fan failure error when I was using it outside in 95 degree weather, however, by the time I got back to the shop, it was behaving again, so I'm not sure if it was just overheated, or cranky, or what the problem was.

One thing I do wish the amps had was ethernet control instead of USB control.  Using the software is very simple to configure and monitor the amps, but having to connect USB to do that is certainly less than convenient.

When I got the PLD 4.5's, they replaced PLX 3602's.  Into an 8 ohm load in 4 channel mode, the amps ran circles around the 3602's.  When in 4 ohm at 4 channels, they seemed pretty comparable, although I rarely used them in that configuration.

One thing I really noticed is that the PLD's weren't as sensitive to voltage drops as the 3602's were.  That was the primary reason for me to get rid of the 3602's.  If you had bad power and there was enough voltage sag, they would reset themselves.  Used in the same environments, I've yet to run into that issue with the PLD's, which makes me believe they are in a closer class to the PL380 amps for touring durability performance.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Scott Holtzman on August 09, 2019, 01:30:12 pm
I've got a rack of PLD 4.5's.  The flexibility of the amplifiers is pretty awesome, as you can easily re-configure them for your needs.  My amp rack can be set as a 3 channel system if I want 4500 watts left, right and sub, or up to a 12 channel system if I want to use the amp rack as multiple monitor mixes.

I did have one unit recently give me a fan failure error when I was using it outside in 95 degree weather, however, by the time I got back to the shop, it was behaving again, so I'm not sure if it was just overheated, or cranky, or what the problem was.

One thing I do wish the amps had was ethernet control instead of USB control.  Using the software is very simple to configure and monitor the amps, but having to connect USB to do that is certainly less than convenient.

When I got the PLD 4.5's, they replaced PLX 3602's.  Into an 8 ohm load in 4 channel mode, the amps ran circles around the 3602's.  When in 4 ohm at 4 channels, they seemed pretty comparable, although I rarely used them in that configuration.

One thing I really noticed is that the PLD's weren't as sensitive to voltage drops as the 3602's were.  That was the primary reason for me to get rid of the 3602's.  If you had bad power and there was enough voltage sag, they would reset themselves.  Used in the same environments, I've yet to run into that issue with the PLD's, which makes me believe they are in a closer class to the PL380 amps for touring durability performance.

There are many ways to extend USB over Ethernet.  The Easiest is a Raspberry Pi box for under $30.  You plug the USB into the Pi then run a little client on your Win or Mac box that is on the same network.

I use this solution for Crown XTI's

http://www.virtualhere.com/usb_server_software
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Dan Richardson on August 10, 2019, 09:10:17 am
PLD's weren't as sensitive to voltage drops as the 3602's were.  That was the primary reason for me to get rid of the 3602's.

Retired my PLX3002's for the same reason.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Dan Richardson on August 10, 2019, 09:16:51 am
http://www.virtualhere.com/usb_server_software

Been meaning to check this out. Looks like it should work for ancient serial-port control devices, too. And the server can be an obsolete Android phone or tablet from your junk drawer.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: boburtz on August 10, 2019, 01:55:19 pm
There are many ways to extend USB over Ethernet.  The Easiest is a Raspberry Pi box for under $30.  You plug the USB into the Pi then run a little client on your Win or Mac box that is on the same network.

I use this solution for Crown XTI's

http://www.virtualhere.com/usb_server_software
We have been doing this for a while now. The QSC software is temperamental when trying to maintain a connection to multiple amplifiers, it just doesn't do it reliably. It's not for real-time monitoring, just for setting up presets, etc.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Brian Jojade on August 11, 2019, 01:23:56 am
There are many ways to extend USB over Ethernet.  The Easiest is a Raspberry Pi box for under $30.  You plug the USB into the Pi then run a little client on your Win or Mac box that is on the same network.

I use this solution for Crown XTI's

http://www.virtualhere.com/usb_server_software

Yeah, I built the usb over Ethernet thing way back when the PLD amps first came out. At best, it sorta worked. Built in Ethernet would just be better in so many ways.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: justinmquinn on August 14, 2019, 09:05:30 am
When I got the PLD 4.5's, they replaced PLX 3602's.  Into an 8 ohm load in 4 channel mode, the amps ran circles around the 3602's.  When in 4 ohm at 4 channels, they seemed pretty comparable, although I rarely used them in that configuration.

One thing I really noticed is that the PLD's weren't as sensitive to voltage drops as the 3602's were.  That was the primary reason for me to get rid of the 3602's.  If you had bad power and there was enough voltage sag, they would reset themselves.  Used in the same environments, I've yet to run into that issue with the PLD's, which makes me believe they are in a closer class to the PL380 amps for touring durability performance.

Interesting comparison.  It should be expected for the 4.5s to outperform the pl380s in 8 ohms, they're rated quite a bit higher.

We use PLX amps on our main tops at the moment and have been very happy.  We have not yet experienced the resetting issue you mention although I have heard about it from others.  I would totally swap them for PLDs for the DSP and flexiblity but many class D amps I have heard on highs sound overly harsh, I was worried the PLDs would suffer the same issue so I have avoided them for tops.
Do you notice a harshness?
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Caleb Dueck on August 14, 2019, 10:54:30 am
Interesting comparison.  It should be expected for the 4.5s to outperform the pl380s in 8 ohms, they're rated quite a bit higher.

We use PLX amps on our main tops at the moment and have been very happy.  We have not yet experienced the resetting issue you mention although I have heard about it from others.  I would totally swap them for PLDs for the DSP and flexiblity but many class D amps I have heard on highs sound overly harsh, I was worried the PLDs would suffer the same issue so I have avoided them for tops.
Do you notice a harshness?

It's a bit unfair to lump all class D amps together.  It's a fairly mature technology with many sub-variants, some of which sound worse than others. 

It would be fun to compare the newest generation of Powersoft, Linea, Lab, PKN, Crown, Yamaha, Camco, and d&b on the same speakers.  My guess is there is more difference between cheap and expensive than "good D" vs H. 
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Tim Weaver on August 14, 2019, 11:51:59 am
Miller Pro Audio bought a bunch of PLD amps for their subs and quickly had a lot of amp failures when the amps were loaded down. After about a year they abandoned the PLD for sub duty and went back to anything but. Now, you may not be driving your rig as hard as they do, so the PLD may be OK, but just know when the going gets tough the PLD often gives up.

They have been fantastic in all other roles. For tops, monitor, SOS, etc. Just not driven hard on subs.

To be fair, these amps are asked to deal with 100 degree ambient emps in dusty, dirty, humid, sometimes rainy conditions often loaded down to 2 ohms per channel. So not light duty use at all. YMMV
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Robert Healey on August 14, 2019, 11:57:24 am
Miller Pro Audio bought a bunch of PLD amps for their subs and quickly had a lot of amp failures when the amps were loaded down. After about a year they abandoned the PLD for sub duty and went back to anything but. Now, you may not be driving your rig as hard as they do, so the PLD may be OK, but just know when the going gets tough the PLD often gives up.

There were some initial problems with the PLD/CXD amps that QSC fixed with firmware, and in some cases, hardware updates.

Bob Lee describes it in this thread: https://forums.prosoundweb.com/index.php/topic,157135.10.html
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Mark Wilkinson on August 14, 2019, 02:34:53 pm
I know i said in an earlier post, that I'd choose a PLD4.5 over a PL380 for the flexibility....and the fact that if I'm close to driving my subs to the full output of the PLD, I should probably be thinking about getting more subs than more amp..

However, having said that.....if I knew the amp was only going to be used for subs, there is zero question in my mind that the PL380 is the better sub amp.
Just like everyone has said....

Justin...where did you get the PLDs are rated higher at 8 ohms? Published specs I've seen say PL380 has 1500W, and PLD4.5 has 1150W.
Those specs match measurements I've made of the amps under an 8 ohm load  (when trying to learn limiters)
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Justin Quinn on August 15, 2019, 08:32:09 pm
I know i said in an earlier post, that I'd choose a PLD4.5 over a PL380 for the flexibility....and the fact that if I'm close to driving my subs to the full output of the PLD, I should probably be thinking about getting more subs than more amp..

However, having said that.....if I knew the amp was only going to be used for subs, there is zero question in my mind that the PL380 is the better sub amp.
Just like everyone has said....

Justin...where did you get the PLDs are rated higher at 8 ohms? Published specs I've seen say PL380 has 1500W, and PLD4.5 has 1150W.
Those specs match measurements I've made of the amps under an 8 ohm load  (when trying to learn limiters)
My mistake, thank you for pointing this out.  I was replying to this from Brian
When I got the PLD 4.5's, they replaced PLX 3602's.  Into an 8 ohm load in 4 channel mode, the amps ran circles around the 3602's.  When in 4 ohm at 4 channels, they seemed pretty comparable, although I rarely used them in that configuration.
In which he was comparing the PLD4.5s to the PLX3602.  When I said the "PL380's" were rated lower in 8 ohms I actually meant the PLX3602's (725W X 2 @ 8ohms) which are, in fact, rated lower per channel in 8 ohms.

My mistake.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Dan Richardson on August 16, 2019, 08:37:53 am
Does anyone here have experience as to how Peavey's IPR2 7500 would compare to these on sub duty?
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Justin Quinn on August 24, 2019, 08:35:26 am
Thanks to Dave I got a PL380 on Thurs.  I had about 15min to listen to it before I had to throw it in the rack for this weekend's shows.  It definitely has a decent amount of power on the subs, and doesn't sound as harsh as other class D amps on highs, so I am currently fairly impressed.  Time will tell.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Brian Jojade on August 25, 2019, 02:04:59 am
Does anyone here have experience as to how Peavey's IPR2 7500 would compare to these on sub duty?

From what I've seen with them, nowhere near as well if you push them hard.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Scott Holtzman on August 25, 2019, 03:30:10 am
From what I've seen with them, nowhere near as well if you push them hard.

I got rid of four of them and,replaced with Lab Grupen FP6400 .  huge difference.  The IPR's have no current reserve and they won't accept 240V
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Justin Quinn on August 25, 2019, 11:41:59 am
Does anyone here have experience as to how Peavey's IPR2 7500 would compare to these on sub duty?

I have no experience with these but Peavey is making bold claims saying their amp can do 2x3750 watts @ 2 ohms at under 15 pounds for $1,000.  Peavey isn't what it used to be so I would proceed with caution.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Tim McCulloch on August 25, 2019, 02:20:22 pm
I have no experience with these but Peavey is making bold claims saying their amp can do 2x3750 watts @ 2 ohms at under 15 pounds for $1,000.  Peavey isn't what it used to be so I would proceed with caution.

I don't doubt that Peavey will meet their specification, the question is "for what duration"?  That's probably why Scott doesn't like the way they perform on subs - I'm betting the amp goes into current limiting either because of insufficient current reservoir or the PSU is current-limited on the mains supply side.  His comment about them not doing 240v reflects that.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Dave Pluke on August 26, 2019, 04:49:41 pm
Does anyone here have experience as to how Peavey's IPR2 7500 would compare to these on sub duty?

I have the Crest variants of the 5.0 and 7.5.  Both went into permanent "ACL" error mode when stored in my warehouse.  It's not climate controlled, but it is tempered.  Note that no other piece of equipment similarly stored has ever hiccuped.

Never had a chance to push them hard, but would hesitate to recommend them for any duty based on the above.  To make matters worse, they're not even heavy enough to use as door stops!

Dave
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: David Morison on August 27, 2019, 09:53:06 am
I got rid of four of them and,replaced with Lab Grupen FP6400 .  huge difference.  The IPR's have no current reserve and they won't accept 240V

Not sure I follow - they absolutely will run on 240V supplies, otherwise they wouldn't be able to sell them here in the UK (or in much of the rest of the world).

Not disagreeing that the Lab FP should be a better amplifier, all the same.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Scott Holtzman on August 27, 2019, 12:52:17 pm
Not sure I follow - they absolutely will run on 240V supplies, otherwise they wouldn't be able to sell them here in the UK (or in much of the rest of the world).

Not disagreeing that the Lab FP should be a better amplifier, all the same.

Not the US versions, and they are not convertible.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Caleb Dueck on August 27, 2019, 09:48:38 pm
Not the US versions, and they are not convertible.

Plugged a US version into 240V power once.  Lots of magic smoke.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Scott Holtzman on August 28, 2019, 02:39:53 am
Plugged a US version into 240V power once.  Lots of magic smoke.

Me too,  the inlet connector made me think it had a wide voltage input.  Was sitting on couch with my wife, had run feeder up from the basement laundry room and was sitting on the couch with a little lunchbox distro on floor.  Unpacked the thing,  plugged it in and let all the smoke out.  The dog ran away and the wife was laughing hysterically before she asked how much that cost?

Shockingly Peavey fixed it for free!

I used four of them for 2 years with JBL STX-828S,  they didn't overwhelm but got the job done.  The FP-6400's are noticeably better.  Right now I am running them one channel per driver, I am going to try bridged that will take me from having 1300W available to each driver to 3200W.   I don't expect a huge difference but it is an 8000W peak speaker. 



Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Dan Richardson on August 29, 2019, 08:30:20 am
they didn't overwhelm but got the job done.

That's where I'm at with mine. I have a pair, each driving a 3TX over an Orbit Shifter. They replaced 4 bridged PLX3002s.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Jeremy Young on August 31, 2019, 01:33:55 pm
I'm using a pair of Crest Prolite 7.5's for my passive rig, which is two Danley SM80's and up to four JTR Orbit Shifters in 4-ohm. I drive two subs on one channel, and the top on the other channel of each amplifier to spread out the current across two separate 20A 120v circuits.  Processing at the moment is an EV DC-one.  I'd love a Danley SC48 or DNA20K4, or even a pair of Powersoft K10-DSP's, but I haven't yet come anywhere close to maxing out what I can do with my current amps/processing so I have been putting my capital into other upgrades first.  I figured I'd use them until they broke for their price, but so far I've been very impressed with the rig. Sorry for the slight topic swerve.

To relate back to the OP, I have not used the PL380 but I own a QSC PLD4.2 that I use for monitors and the interface/processing/form factor are extremely convenient.  The PL380 has a great reputation for subwoofer applications but you would need external processing which may or may not be important to you.  The downside with the PLD series is that the display screen is virtually useless on a sunny day and I wish they offered ethernet connectivity and not just USB.
Title: Re: QSC PLD4.5 vs PL380 on subs
Post by: Justin Quinn on September 01, 2019, 11:50:11 am
To relate back to the OP, I have not used the PL380 but I own a QSC PLD4.2 that I use for monitors and the interface/processing/form factor are extremely convenient.  The PL380 has a great reputation for subwoofer applications but you would need external processing which may or may not be important to you.  The downside with the PLD series is that the display screen is virtually useless on a sunny day and I wish they offered ethernet connectivity and not just USB.

Thank you for the input.  Processing is not an issue for us.  I got a PL380 since I wrote the original post and have taken it out a few times.  Both myself and my team members are impressed at how much boom this thing can put out before you hit the -10 lights.  In fact we had a lady approach me and say (and I quote) "there's too much boom boom".  Any amp that sends middle aged women complaining about "too much boom boom" is an amp worth owning.

We are still considering a PLD for mains/fills/monitors.  I, too, wish these amps had ethernet control.  I wish they had Dante too but oh well.  However I may hold off and swap our mains amps out for powersoft, the T series is an attractive relatively affordable package and/or you can get used K series for a decent price.