Pro audio power amps

Also on side note, vocals/midrange can have very high dynamic power peaks easily and can actually put good amount stress on amps and speakers. Midrange is usually where all the energy is. That's why its good use same size amp for mids as it is lows/subs but, of course doesn't apply to the explained situation you presented... It's just most likely user error on their part.

 

I managed to repair the speaker by replacing the blown cap, though I had to bootstrap the fuse. It had a pair of 211-2 automotive bulbs soldered together acting as fuse, but I think the bases are aluminum or something so I couldn't solder them so I just wound up stringing some wire through the bases and hoped for the best.

An interesting development though, the second set of parallel jacks on the speaker were missing. Not just fallen off inside the cabinet, but completely missing along with the wire. That means someone stuck their grubby hands inside and took it. I don't know if that could have resulted in damage when they were yanking things out, but it's certainly a possibility.

 

Currently at home I've got a Bryston 2B, 3B and 4B on the horns, woofers and subs respectively

At the studio it's just a single QSC amp feeding the cabinet through a passive crossover in the cab.

 

Really nice stuff and great sounding gear. I would have some bryston amps myself but, very difficult to find and even if they become available, they are sold sold for price of a nice used car or truck. They're very expensive.

I plan on doing all in one type system project in near future. Friend of mine is hooking me up with 3 jbl 4648 bass bins, one jbl 4645 loaded 2245h Subwoofer and I plan on using them actively. One of the loaded 4648 has a pair of like new jbl 2225h woofers in it and plan on using pair of 4648 bass bins and strapping a altec 511b horns on top...and I'm gonna buy some amps later on to actively run them. Still deciding on the amps to use but, I have basic idea what I plan on getting.

And later on in future gonna purchase some jbl d2 compression drivers as an upgrade. The specs and measurements of them are very impressive that I found on altec Lansing heritage fourms. No wonder there used in the jbl m2, touring vtx array systems and everest systems.

 

My Brystons I all scored for ridiculous deals. I actually have three 2B's but they all have different inputs on the back; I've got a local ad posted hoping to trade the RCA or TRS one for another XLR. I haven't heard any of the newer Brystons; mine are all old models. The company recently updated the line with the "Cubed" series (instead of calling it the SST3), but I doubt that will affect used prices very much. Bryston gear on the used market is quite stable and tends to hold value well.

All my PA work is small-time, so I've never gotten into rigs with separate bass bins and horns, even though I see them on sale in the local classifieds and I've been tempted but don't have to space for any of that. About as fancy as I get is running a full range cab with a crossover to include a sub. I've got an event this Friday; not big but I just want an excuse to set up the toys. All the setup and running the cabling is kinda a nice zen exercise. Lifting 500 lbs of gear from the car and up a flight of stairs... not so much.

 

How was the event? Sorry for such late reply or activity on here. Just been too lazy to reformat my laptop and just been using my phone lately again. At least this time around i have decent sized phone thanks to my brother giving me his Sony xeperia ultra which is good size so can make better use on touch screen with my large hands.

 

It went quite well. I was a bit worried I was going to be underpowered, but it turned out alright. It was a big space... maybe 6000 sq ft, 120 people-ish.
Yorkville U15 x2 - biamped with a pair of Bryston 2B's
Behringer B1500X x2 - amped with Yamaha P7000s
Processor: Behringer DCX2496
I was rather impressed with myself that I could actually fit everything into my car. Two tops, two subs, two 4U cases, and a large mic/cable case.
In terms of setup, I should have brought some separate stands for the tops, or gotten a 1-2ft post to mount the U15's higher up on the subs.

In March I'm planning to use the same setup for a two-day event with a 5-piece band (plus some wedges obviously). I've got a Mackie CFX12, but might borrow a friend's 16 channel mixer if we need more. Hmm come to think of it I might need another amp for the wedges... or just bootstrap a powered box mixer into the chain for those.

 

I picked up a Yamaha P4500 amp the other day, which I believe is a precursor to the P##00s series. Sonically, I think it's actually more lively on the top end, but decidedly less oomph in the bottom. I'd run the P4500 on tops and P7000s on subs if I were doing a simple arrangement like that. The P4500 runs quite cool (haven't really pushed it hard yet), though the fan is always on unlike the P7000s which only comes on when needed (at least in theory, I've still never had mine switch on)

So amazingly, that venue managed to set the speakers on fire a second time. I'm not really sure if it's something wrong with the gear, or gross user incompetence. The amp *seems* ok, no weird DC on the outputs, doesn't smell like any of the magic smoke got out, etc. It was the same speaker that went kablouie, and blew the same cap, so I wonder if there's something else gone wrong in the crossover??

I've just completely replaced with new speakers right now. If those go boom, well I guess it narrows it down to the amp or maybe the mixer.

I know at one point those idiots had accidentally hit the mute button on the mixer, but them someone "figured out" that if they plugged their ipod into the tape-out on the mixer and cranked every knob they could find, the sound would eventually bleed out into the speakers. Albeit muffled, so of course they would turn up the amp too, and the ipod all the way. Ugh, so I'm guessing that was probably hard clipping and basically cooking everything with DC for a while.

I can only stupid-proof so much...

 

Steel vs aluminum chassis makes a huge weight difference too.

Oh yeah there are quite a few class D amps out there that are literally just a module from Hypex or B&O, slapped into a pretty (and heavy) fancy machined case with a shiny input circuit up front.

On my local classifieds right now I see a Crown XTI2000 for $500 and XLS602 for $260 (CAD prices). Not the greatest prices, but I'm curious.

edit: and a Behringer EP4000 for $200, which is pretty cheap... but I'm hesitant on Behringer (their old floor monitors are ok, but the amps I've got reliability concerns)

Any experience with Lab Gruppen? I saw this on ebay today... http://www.ebay.com/itm/Lab-Gruppen...901936?hash=item1a0be7fa30:g:tWwAAOSwLN5Wj1vp
I'm always intrigued by 1U rack stuff so this caught my eye. Unfortunately it would be too expensive to import to Canada so it's a no go for me.

 

that's pretty high for older model xti 2000. new xti 2002 retail is 699 and used in mint shape can find it for bout 400-500...i found older xti 4000's for 420 before.

yea, metal types matter. lot of pro stuff use steel because it's cheaper and tougher(that doesn't exactly make them heavier since the gauge of the steel is usually small to help with keeping weight down). i know some complain saying steel doesn't shield as well as aluminum but, it seems to work fine for me so far with stuff i used. i know carver is only company using aluminum so far for their amps.

i heard of lab gruppen company. never used one personally due to them being so dang expensive. i know lot of ht/diy guys with deep pockets swear by them but, i remember reading a test run with an fp model(i think that's right for their current model...forgot which one though) comparing to an i-tech 9000 i believe cause on a pro community website somewhere since lot people were bashing crown for not putting out their rated output numbers.. in the end result the i-tech actually had better sustained power output to the gruppen and the gruppen would shut down at bout 1/8 it's total claim power output....but, still people still believe lab gruppen is the ''audiophile'' brand of pro audio world. they supposedly have their own patent class d topology(i think they call it class f or something....) they look like really wonderful amps though. i did read some of the older ones were really great and that's how they got their reputation started.

 

Was this the bench test you were talking about? http://www.diy.poweraudio.ro/albums/userpics/10001/BENCH_COMPARISON_TEST.pdf
Each one seems to have their strengths (some of those powersoft figures are amazing), though the LabGruppen was obviously operating outside of its range.

I don't think I'd ever need that much power on tap though. I did a dance event last weekend which is arguably as large as I would ever get and was driving my tops with two Bryston 2B's (50W/channel, probably underrated).

Gotta admit, the LabGruppen auction there caught my eye because I never see any of them under $1k. There's very very information or impressions on that one though. If there weren't so many shipping and import fees stacked on top I might have been tempted to try it out.

Purely by numbers, the Benchmark AHB2 is an interesting beast with ridiculously low distortion figures...
http://www.soundstagenetwork.com/in...hb2-stereo-mono-amplifier&catid=97&Itemid=154

 

wasn't that one specifically but, that one is very interesting. the one i saw was a guy testing them on subs since people were claiming the itechs weren't good for subs...shows in that test subs would likely be good choice if deciding on an itech cause below 8ohm loads at full output their hf response shoots way down. seems only the powersofts performed best with great linear response in frequency response vs. impedance.

i wouldn't need that much power either in most cases but, if i end up with certain deals i guess can look at it, it always good to have spare headroom lol. i would get the k10 if i had the money. also for test results i think the macro-tech i's would of performed better in my opinion. they might be class i as well but, uses dual mono linear power supplies and of course zero dsp instead. problem is, i think crown discontinued them...the itechs problem in most cases was undefeatable dsp functions. but, itechs do use great dsp which is considered top end for dac conversion and for crossover functioning though but, if not needed can get in way with lot of things..

i have guy local selling a mint in box macro-tech 12000i for 2800....wish i had the money lol

i heard bout benchmark stuff but, never got into them. they do seem like to make very good stuff. i read quick glimpse on that particular one but, will read full thing in a bit or so.

 

I think if I ever really needed to have that much headroom, I would just rent instead. As much fun as it is to own the gear and play with it, I gotta draw a limit somewhere right?

I don't think I've ever seen a powersoft turn up in Canada. Even searching on ebay there aren't very many, and shipping up to here is ridiculous. <$20 shipped in the US, but >100 to Canada? Ouch...

It seems many of the high end amps are all coming with built in dsp functions. All the giant racks of gear are going the way of the dodo too it seems with the digital mixers. I can't deny the convenience of it; replacing a bi-amp setup with two amps, processor, power distributor... with a single 4-channel amp that handles all the processing that I need. Heck one of those 4-channel QSC PLD amps does all that and only weighs 20 lbs. That could replace my current 6U rack that probably tips in 120. On the other hand, there's a certain physical satisfaction there being able to assemble the rig.

That Benchmark is very pricey... I think I'm just fascinated by the numbers. I have a friend who tried it out (free trial for you Americans) and thought it was good but wasn't blown away by it, especially for the price. He actually felt it was only marginally better than the Bryston 2B which I'm using.

 

well, i would go by how sane, how large and,what your running in home or not determines the amount headroom needed i would think...for mains i can live with even a 15wpc set amp due to sensitivity of my altecs. just for subs is where i require the big power from. i have 3200-3400w of rms/continuous mount of motors for sub duty just about total why i need sometime like my xti 4002 for minimum requirements especially when involves a 6db+ boost at 20hz in peq settings. you be surprised in how some music i listen to and movies that power gets eaten up for the ultra low/subsonic sections... something like a macro-tech 12000i probably be perfect for me for my situation with bout double output of all my subs and with the capability of the macros that excel under 1ohm loads. i ran a 1.5ohm load on the 4002 before and it seem to handle it fine. i gave it a test run and did not heat up as bad as i thought it would but, i wasn't gonna keep it that way since i had other plans in mind...

the xls 2502, i tested under same conditions. the xls 2502 actually seem to run bit cooler under the same load but, again i wasn't gonna keep it that way since i wanted the xls for mains. i didn't buy it for subs.

i agree. it's kinda silly in a way. it seems few companies like qsc still makes different stuff for different types of customers cause they still make dsp-less amps and still make traditional big heavy dual-mono power amps. i was gonna go with qsc at first many times before since they are great amps but, i needed the bit extra dsp function for my purposes and i needed a complete extended control over crossover slopes and frequencies for my purposes. the xti series fit the bill for the money and power. i was gonna get the 6002 but, i didn't have the extra grand on me at the time...i fine use i-techs a lot in ny area but, even used they in above 1k-2k range...

i never see powersoft either on sale used too. there not really a big name type company like crown and qsc. even peavey is more known.

i been curious bout bryston and always wanted one to try but, have hard time finding them. i found one 4bsst but, i think seller wanted over 2k.. and i did once find an old bryston 3b with balanced xlr jacks for sell. seller never had a price. just had for best offer sign...i was gonna make an offer but, something came up and i had to past on it. kinda kick myself to this day for not picking it up. once day if price is right i'll pick one up..

i want an older ashly mosfet power amp too, to try out. those things are nice and lot theaters usually get rid of them for next to nothing. even want to try some of ashly older studio power amps one day. bout over year ago guy had nice one next town over for 100 bucks..rated 200wpc but, at time i already spent bout couple hundred on a big crown ce2000 and i still need to buy christmas gifts so, i had to past....

i haven't read the paper yet but, it seems use some type weird topology design that supposedly developed by THX..interesting but, lot of amps use that. even lot of nad amps use it i believe. it's pretty much a standard in the ht audio industry. yea it is super expensive for some reason. i would test it if i had time but, for item of that price, i'll be afraid to do any form of testing,even simple listening session if i didn't pay for it already.

 

Sanity? That left the station years ago

Fortunately for me, all my gigs are more acoustic in nature and I don't need the crazy power grunt for subs. I've got some cheap Behringer B1500X subs that I run (actually two pairs). Got them used for something like $250 for a pair. Not the greatest sound and they don't reach particularly low... but low enough for my needs, and more importantly I can fit them all upright in the back of my car.

I think if I ever need subs I'll just go the powered route and save myself the hassle. Maybe.

I've been wanting to get my hands on a Crown K1/K2 for a while now. The whole BCA topology which I think the more modern ones are based on, but the K series still have passive cooling. I never see any of the higher end crowns here; I don't think we actually have a Crown dealership in this province at all, and the shop that sold QSC's switched almost exclusively to powered monitors a few years ago. Almost everything in town now is Yorkville (which I like, but there isn't much variety).

Ashly you say? I saw this floating around, but have no idea if it's a good price or not... http://www.canuckaudiomart.com/details/649169279-two-mackie-and-one-ashly-pro-amps/

I think almost all the more modern pro class A/B amps have some sort of feed forward processing that carries the voltage rails ahead of the signal to be more energy efficient. It's just a different flavour of implementation that garners the different classification. I know I read that AHB2 paper a while ago but the details are all jumbled in my head now along with everything else.

I currently have a bunch of old Brystons... an original 3B and 4B-pro, and two 2B's (older 2U case) and two 2B-LP's (same thing but in a 1U case). My favourites are actually the 2B's. According to their rep, the design of the 2B hasn't changed since their inception; supposedly the design is as good as they can make it within that chassis size, and the only updates have been to the parts and transformers over the years as suppliers changed.

Bryston has a reputation for being bright, but I think that's due to the rather large number of old amps floating around that need servicing. My 3B and 4B could really use with a tune-up and recapping. Adding to the confusion also is that Bryston hasn't changed their model names... it's still the 3B, 4B, 7B, etc. but with suffixes. There's the originals, then the NRB, ST, SST, SST2... actually the newest "Cubed" series was just announced a month ago, so now would probably be a good time to shop around as people will be getting into upgrade mode.

For some reason Bryston used prices have been climbing. I got my 4B-pro for $400 but lately I see people asking $1k (CAD). This is maybe the cheapest one I see at the moment: http://www.ebay.com/itm/Bryston-4B-...786076?hash=item1c641e371c:g:RywAAOSwr7ZW2hwG
The 2B's can typically be found around $500.

 

Hmm, found a cheap Ashly for you:
http://www.ebay.com/itm/Ashly-fet-2...131287?hash=item2814e34817:g:U6EAAOSwJQdW-Icw

 

Pro amps? You must try MC2, from England.

 

Yeah, MC2 is right up there with Powersoft and Lab Gruppen (or I think considered a half step down)... but even harder to find over here. Funny though, I just looked over at ebay and there are a few in Canada...

 

that ashly fet2000 is very good price but, of course shipping is gonna kill the deal a bit. i have an ashly fet5000 for 100 bucks on local cl ad but, it's bout state away(not bad really since dalaware is like right next door) but, i already have plans on purchases this weekend. i'm gonna try picking up pair of ev hr9040 horns locally i found. they're very large format horns and are don keele designs so i was told that they are very good horns and will make my 808-8b drivers shine down at 500hz so i'm gonna buy them out of curiosity but, of course i'll need to buy adapters since they were designed for altec larger 288/290 1.4'' drivers. one day though i pick up larger format drivers to try but, i'm happy with the 808-8b's and i really don't need 130db type spl and very high power handling that the large altec drivers are capable of so....i can wait on that.

i actually seen couple mc2 amps around before but, forgot where. i wouldn't consider mc2 around powersoft or lab gruppen territory really. all companies have their greats and not so greats. i just love crown stuff lot cause they have proven to be sturdy amplifiers for ridiculous loads making them more idiot proof(as can tell, lot of times i can be an idiot sometimes) than lot other amps(someone loaded a 1ohm bridged load on a macro-tech 2400 once and kept wondering why his speakers kept blowing...the crown while supposedly not rated for that ype load spec sheet it still delivered without blowing or shutting down lol....but, some people. what can you do. i was actually surprised he ran it whole year like that without no amp failures)....


try finding a dsi amp. they're basically xti series in a different shell. while the xti 6002 is 2k you can probably find a dsi 6000 for like around 500-600 bucks. it'll perform lot better than a k2 and will most likely have cleaner/better sound cause it uses no ic's in the output section like the k series does. the ce4000 too is something to look at as well for that type of tech. can find them between 350-500. lot of people praised the ce4000 while complained and ridiculed the ce1000/2000 cause they were typical heavy class a/b amps and going out a lot but, most people were probably idiots and never used them right and never kept them clean. i never had issues when i had my ce2000 before and driven it real hard on 4ohm subs before. i even added open cell filters to it to prevent dust/debris getting inside. but, the ce4000 is something to look at too for bca/class I tech.

 

That fet2000 doesn't even ship to Canada and the fet1000 on the canuck side seems somewhat expensive in comparison. There's an Ashly SRA120 on ebay (because I like 1U stuff for some reason), but it costs more to ship than the actual amp itself. Bleh.

From stuff I've read online, MC2 always seemed to be compared with Powersoft and LabGruppen but "not quite" up with them. Same with FFA Audio. There's another name or two up here I can't remember. Kinda moot anyways; I don't see myself spending that kind of money on those amps anytime soon. There's actually some MC2's in Canada though, hmm... http://stores.ebay.ca/Electric-Soun...14544011&_sid=440965201&_trksid=p4634.c0.m322

Crown amps are somewhat rare up here to begin wtih. I don't think I've even seen a dsi here.