ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 2 [All]   Go Down

Author Topic: CROWN I TECH 8000 for subs ?  (Read 17222 times)

Randy Frierson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1403
CROWN I TECH 8000 for subs ?
« on: June 05, 2010, 06:21:20 PM »

So i haven't been keeping up with the crown I tech amps..On Ebay there are some I tech 8000's for $1,799 each and i'm in eed of sub amps...You Crown guys what do you think? Are they fixed and how do they do on subs, i guess i would run at 4 ohms as seems as no benefit to running at 2 ohms....

PS  If anyone has a Lab FP13000 for sale or rent i'm in need

thanks   Randy

randy@concertsystemsusa.com
Logged

Tim McCulloch

  • Newbie
  • *
  • Offline Offline
  • Posts: 0
Re: CROWN I TECH 8000 for subs ?
« Reply #1 on: June 05, 2010, 07:25:01 PM »

Hi Randy-

We use ITech 8000 on JBL VT4880 subs and are very happy with the results @ 4 ohms.  I suggest you use a cable run to each sub, rather than jumping the speakers together.

Have fun, good luck.

Tim Mc
Logged
"Will you stand by me against the cold night, or are you afraid of the ice?" Crack The Sky

Randy Frierson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1403
Re: CROWN I TECH 8000 for subs ?
« Reply #2 on: June 05, 2010, 07:35:16 PM »

thanks   R
Logged

Mark Lonow

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 72
Re: CROWN I TECH 8000 for subs ?
« Reply #3 on: June 06, 2010, 06:17:57 AM »

was surprised the iteck did not make ur last sho0t out

its time for a nother sub amp shoOtout  wit:

iteck 8000/hd
plm20000Q lab
K10/20 powersoft

compared to the D12 and L8

maby ma5002 on hand as the control

let me know how it goes Very Happy

$/watt used iteck or even macros  hard to beat
Logged

Randy Frierson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1403
Re: CROWN I TECH 8000 for subs ?
« Reply #4 on: June 06, 2010, 01:07:26 PM »

i was just wondering because they are on ebay cheap..I don't like a amp that is not optimized to run at 2 ohms...I'm only looking as my order from FFA is stuck in customs and i need sub amps for this weekend....decided to get the 2nd best brand and get a Lab FP13000...thanks  Randy

www.fullfataudio.com  
Logged

Silas Pradetto

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 3047
Re: CROWN I TECH 8000 for subs ?
« Reply #5 on: June 06, 2010, 10:14:09 PM »

Randy, I don't like amps not optimized to run at 2 ohms either. But put it this way--most amps are quite current limited at 4 ohms already. This is obvious since power should exactly double into double the load, if voltage is constant, and power rarely doubles from an 8 ohm load to a 4 ohm load in most amps. But in Itechs, it is very close to double. The current limit doesn't hit until 2 ohm loads, but it can still sustain big power for 20ms or so into 2 ohms, a period which is good for most kick drum hits or other impulse signals.

I'm not defending Itechs in any diehard way, just inviting you to look at them differently. They do fine into 2 ohms loads, I do it all the time.
Logged

John Roberts {JR}

  • Newbie
  • *
  • Offline Offline
  • Posts: 0
Re: CROWN I TECH 8000 for subs ?
« Reply #6 on: June 06, 2010, 11:31:37 PM »

Silas Pradetto wrote on Sun, 06 June 2010 21:14

Randy, I don't like amps not optimized to run at 2 ohms either. But put it this way--most amps are quite current limited at 4 ohms already. This is obvious since power should exactly double into double the load, if voltage is constant, and power rarely doubles from an 8 ohm load to a 4 ohm load in most amps. But in Itechs, it is very close to double. The current limit doesn't hit until 2 ohm loads, but it can still sustain big power for 20ms or so into 2 ohms, a period which is good for most kick drum hits or other impulse signals.

I'm not defending Itechs in any diehard way, just inviting you to look at them differently. They do fine into 2 ohms loads, I do it all the time.


The divergence from perfect doubling when you halve the load impedance, is not  caused by current limiting. It could be but it typically isn't.

Just like your lights dim when you draw too much power from the wall, there are several internal paths inside the power amp that have losses related to the average output current being passed, like simple low value resistors So everything from the output power devices to the power supply transformer windings will drop voltage in series related to the current output, that doesn't make it to the output load.

These losses appear more significant at 2 ohms since amplifier output power is a function of the voltage squared, so linear voltage losses make for nonlinear power output reduction.

Some class D amps have power characteristics that show evidence of simple current limiting at 2 ohms, while the relationship you describe for most power amps is simple resistive (and device saturation voltage)  losses inside the amp.  

JR
Logged
 https://www.resotune.com/


Tune it, or don't play it...
-----

Ken Freeman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2119
Re: CROWN I TECH 8000 for subs ?
« Reply #7 on: June 08, 2010, 02:21:57 AM »

Hey Randy.

I think these are a good fit, but a 2.7 ohms.  Run them at 208 and put three cones on a side.  In the case of VT 4880's, that is three boxes per 2 channel amp.  Both the cones and amps are very happy.  We have done this a bunch of times and it is a happy pairing.

As I trust nothing, I am a more a 4 ohm guy.  I bought Itech 6000's, but 50% more.

ken
Logged

Jason Phair

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 336
Re: CROWN I TECH 8000 for subs ?
« Reply #8 on: June 08, 2010, 08:42:42 PM »

I'm a 2-ohm guy, but that's because I spent a few years hauling around Crest 9001's!  Laughing
Logged
Jason Phair

Randy Frierson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1403
Re: CROWN I TECH 8000 for subs ?
« Reply #9 on: June 08, 2010, 11:23:58 PM »

thanks, there are some screaming b stock deals, but i decided on the Lab FP 13000...This is because i can't count..i have all of my new FFA amps coming in but misread the calandar and left myself short for a run of shows...that was an exspensive misread....thanks for the input   Randy
Logged

Tim Padrick

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 5008
Re: CROWN I TECH 8000 for subs ?
« Reply #10 on: June 14, 2010, 12:56:40 AM »

From http://www.abeltronics.co.uk/amptesting/amp-meet-three.php about the FFA10000: "Severe oscillation at clip.... 10khz sine wave severely distorted at all load impedances. Full report soon…"

Scary.

Paul Bell

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1009
    • http://pbellsound.com/
Re: CROWN I TECH 8000 for subs ?
« Reply #11 on: June 14, 2010, 06:33:29 AM »

WOW. The QSC PL380 did perty good, eh? HUH.
Logged
Paul Bell
PBell Sound New York City
paulATpbellsound.com
User/provider for:
McCauley, BASSMAXX, APB DynaSonics, QSC, Ashly, DBX, Rane Digital, Rapco, Faital Pro

Phil Lewandowski

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1101
Re: CROWN I TECH 8000 for subs ?
« Reply #12 on: June 14, 2010, 11:33:42 AM »

Paul Bell wrote on Mon, 14 June 2010 06:33

WOW. The QSC PL380 did perty good, eh? HUH.


That's what I thought, cool.  I've been very happy with mine, so I wouldn't doubt it, and was easily worth the $1800 I paid for it.
Logged
"It is good to be Alive!"

L and L: Live Sound
landllivesound.com

Randy Frierson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1403
Re: CROWN I TECH 8000 for subs ?
« Reply #13 on: June 14, 2010, 12:03:38 PM »

As the US distributor i will get all the facts on this FFA 10000.
I cam assure you that the amp they are testing is a lone soldier and that there are hundreds of 10000DP's in the field working flawlessly..I need to find out if this amp was sent in for testing by FFA or was it a customers amp with a unique issue...Transparency i promise....Randy
Logged

Randy Frierson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1403
Re: CROWN I TECH 8000 for subs ?
« Reply #14 on: June 15, 2010, 02:14:21 AM »

I have asked FFA to reply to this here....Randy
Logged

Arik Perelman

  • Newbie
  • *
  • Offline Offline
  • Posts: 11
    • http://www.gearconnection.com
Re: CROWN I TECH 8000 for subs ?
« Reply #15 on: June 18, 2010, 05:26:18 PM »

Not that it really matters now, but to throw my $.02 in, we were running (2) 18" x 2 per side of an IT8K for years with fantastic results. Last year we upgraded to the IT12KHD and have gotten even better results due the extra power.  In fact we have always ran all of our racks at 2 Ohms and have always had terrific results! The key for us is wiring our subs for all 4 pins of the NL4, so each driver has it's own pair of leads. It basically doubles the amount of copper running from the amp to the sub.  Works really well.
Logged

KeithBroughton

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 480
Re: CROWN I TECH 8000 for subs ?
« Reply #16 on: June 21, 2010, 07:58:47 AM »

Quote:

The key for us is wiring our subs for all 4 pins of the NL4, so each driver has it's own pair of leads. It basically doubles the amount of copper running from the amp to the sub. Works really well.

This is an important consideration in low impedance, high power cable runs!
Power and damping factor losses can add up on relatively short runs.
Logged
I don't care enough to be apathetic.....

ProSoundWeb Community

Re: CROWN I TECH 8000 for subs ?
« Reply #16 on: June 21, 2010, 07:58:47 AM »


Pages: 1 2 [All]   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.032 seconds with 23 queries.