Crown xti4000 vs. Itech 4000

Is this amp OK?
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jcmbowman
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Re: Crown xti4000 vs. Itech 4000

#16 Post by jcmbowman »

gilscales wrote:can anybody talk about the 2.5 ohm load being good with the itech?, I mean from experience.
I've helped on a few gigs where they used itechs with 3 8-ohm drivers per side (2.66 ohm load) for 10+ hours straight without a problem (outdoors in the summer, no less). They barely got warm. I wouldn't do that with an XTi.
Low End Junkie for over 20 years.

4 DR250s
4 Tuba36s @ 30" wide
2 ATs
...and a very serious addiction to the smell of BB sawdust and curing PL.

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netwerks
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Re: Crown xti4000 vs. Itech 4000

#17 Post by netwerks »

Given that statement Jcmbowman,

Back to OP question...

Could one not series/parallel 4 subs boxes together with 3012lf or 3015lf to keep the load @ 8ohm per side to run @300w per sub cab while running 2-4 DR or OT on the other side? (Perhaps a IT6000 would be a better matchup with max output voltage for those drivers vs the IT4000)

Theory is to negate having to buy "two lower-range" amps with a goal to realize reduced weight, pack and power draw.

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jcmbowman
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Re: Crown xti4000 vs. Itech 4000

#18 Post by jcmbowman »

netwerks wrote:Given that statement Jcmbowman,

Back to OP question...

Could one not series/parallel 4 subs boxes together with 3012lf or 3015lf to keep the load @ 8ohm per side to run @300w per sub cab while running 2-4 DR or OT on the other side? (Perhaps a IT6000 would be a better matchup with max output voltage for those drivers vs the IT4000)

Theory is to negate having to buy "two lower-range" amps with a goal to realize reduced weight, pack and power draw.
The Itech4000 outputs 100 Volts, the 6000 outputs 110 Volts, the 8000 outputs 126 Volts. So, whatever the voltage limit for your subs, when you series/parallel you need to double that voltage. In my case with the T36s the voltage limit is 60 Volts, so to series/parallel I'd need something capable of 120 Volts.
Low End Junkie for over 20 years.

4 DR250s
4 Tuba36s @ 30" wide
2 ATs
...and a very serious addiction to the smell of BB sawdust and curing PL.

sine143
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Location: Raleigh NC

Re: Crown xti4000 vs. Itech 4000

#19 Post by sine143 »

if you are driving them into the as hard as they can take.
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

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netwerks
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Re: Crown xti4000 vs. Itech 4000

#20 Post by netwerks »

The recommended is 50v on 3012lf in a T39 so a I-tech 4000 or 6000 is capable of running a 4 cab series/parallel to full power, hell you could even get really wierd run 8 x 3012lf cabs/ side in that wiring config. :twisted:

One just has to make a hard decision on whether it's beneficial to carry less amps and spend less money vs. risking a show on one amp with no potential backup in the event of failure.

sine143
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Location: Raleigh NC

Re: Crown xti4000 vs. Itech 4000

#21 Post by sine143 »

yeah dude, one 4000, 8 T48s (4 per side, series parallel).
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

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netwerks
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Re: Crown xti4000 vs. Itech 4000

#22 Post by netwerks »

So original poster. There's your answer.

Just have to make the decision if "less is really more".

From a cost, pack space, power and weight perspective it is, but you need to ask yourself if you can live with the risk only having one amp on site in the event of failure.

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jcmbowman
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Re: Crown xti4000 vs. Itech 4000

#23 Post by jcmbowman »

sine143 wrote:yeah dude, one 4000, 8 T48s (4 per side, series parallel).
Actually, you could run 16 T48s in that configuration, so long as you're okay limiting them to 50 Volts per cab. The 3015LF in a T48 can actually be limited at 60 Volts, so if you're going to series/parallel you may want the itech 8000.


And, regardless of how appealing it may be, I'd rather have a pair of amps - if you need that much output, you also need redundancy. Knowing that each amp could carry the load by itself would be nice, but I'd still rather have two amps and only run them half as hard.
Low End Junkie for over 20 years.

4 DR250s
4 Tuba36s @ 30" wide
2 ATs
...and a very serious addiction to the smell of BB sawdust and curing PL.

sine143
Posts: 3066
Joined: Sat Feb 06, 2010 3:27 pm
Location: Raleigh NC

Re: Crown xti4000 vs. Itech 4000

#24 Post by sine143 »

yeah, at that point, 16 t48s would be easier on 2 amps, 1 stage left, 1 stage right. would also help you in case of a failure, although I'm sure you would need more amps.
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

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gilscales
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Location: Seal Beach, CA

Re: Crown xti4000 vs. Itech 4000

#25 Post by gilscales »

jcmbowman wrote:
gilscales wrote:can anybody talk about the 2.5 ohm load being good with the itech?, I mean from experience.
I've helped on a few gigs where they used itechs with 3 8-ohm drivers per side (2.66 ohm load) for 10+ hours straight without a problem (outdoors in the summer, no less). They barely got warm. I wouldn't do that with an XTi.
Glad to hear that as that would be very close to the min. load i would ever choose to run.


Just bought the ebay one listed earlier in the post, made an offer of $1100 and was accepted so with shipping that's $1147 and change for a b stock with 6 year warranty that someone supposedly bought from proaudiostar for an install that was cancelled, they said they still have the box and that the warranty was not yet registered, same thing direct from proaudiostar is $1499 with the 3+3 warranty and free shipping so it would seem i have negotiated a screamin' deal (fingers are crossed that it is as advertised, if not i have the paypal protection)
Built; T18, 2 x J110 2510II MA

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gilscales
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Re: Crown xti4000 vs. Itech 4000

#26 Post by gilscales »

Thanks again for the heads up on this one Netwerks, made an $1100 offer and it was accepted, the bing cash back only applies to full price so I did not qualify for that but still paid less than $ 1150 OTD
Built; T18, 2 x J110 2510II MA

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netwerks
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Re: Crown xti4000 vs. Itech 4000

#27 Post by netwerks »

Generally what I do in that situation is contact the seller and have them adjust the buy it now price and then buy it so I get the cashback. Regardless you got a good deal with a great warranty. Good job.

sine143
Posts: 3066
Joined: Sat Feb 06, 2010 3:27 pm
Location: Raleigh NC

Re: Crown xti4000 vs. Itech 4000

#28 Post by sine143 »

anybody have any insight on the difference between the itechHD and the itech? features? power? wheres the price difference come into play.
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

User avatar
jcmbowman
Posts: 1263
Joined: Fri Feb 01, 2008 3:40 pm
Location: Detroit, MI

Re: Crown xti4000 vs. Itech 4000

#29 Post by jcmbowman »

sine143 wrote:anybody have any insight on the difference between the itechHD and the itech? features? power? wheres the price difference come into play.
the HD series has slightly higher output, and a dramatically improved DSP section. There are some new features in the DSP, but more importantly, all the DSP circuitry has been upgraded.
Low End Junkie for over 20 years.

4 DR250s
4 Tuba36s @ 30" wide
2 ATs
...and a very serious addiction to the smell of BB sawdust and curing PL.

guitarkeys.com
Posts: 309
Joined: Tue Feb 23, 2010 12:10 pm

Re: Crown xti4000 vs. Itech 4000

#30 Post by guitarkeys.com »

JCbowman,

You stated that the 3015lf T48 can be limited at 60v. I just want to check my math to make sure I am setting up my limiting correctly.

That would be limiting (1) at 360watts: 10 Ohm x 360 watts = 3600 > sqrt = 60 v
To limit (2) in parallel at max would be: 5 Ohm x 900 watts = 4500 > sqrt = 67 v
To limit (2) in parallel at 400 watts would be: 5 Ohm x 800 watts = 4000 > sqrt = 64 v

Didn't know you were going to have a math test today! But seriously, I just want to protect my investment. I limit at 400 using a 80 hz sine wave. If I did my match right and you have reasons for limiting at 360 watts, please share so that I don't blow anything up. Don't know if it makes a difference, but my system is used for live music.

Jamie
Jamie
Fayetteville, AR
In Pursuit Of Audio Perfection
"A Bad Mix is Bad at Any Volume"

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