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Need amp for JBL GTi MKII - Page 3

post #61 of 68
3/17/13 at 10:59am
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Quote:
Originally Posted by BassThatHz View Post

The Crown iTech's are dual 1-ohm stable, that's how I power my stuff (stereo 1-ohm). Been running like that for almost a year now, no problems.
But the iTech's don't like being bridged at any ohmage IMO, best to run it stereo 3-ohm; it will put 8000watts into the driver in that mode; which is enough power to cook the subwoofer on-demand.
(You could even hook two of them up stereo 1.5-ohm if you wanted, ~4kW per sub.)

This is an 8000 doing stereo 1-ohm, (the other sub on the other channel is doing the same excursion.)

Thank you for that suggestion. I think I've decided on a pair of the Emotiva XPA-1's. I'm not really digging the PA amps. It's just a personal preference. If TC sounds would come out with their plate amps, then I may consider one of those. Whatever happened to them being released at the end of 2012? People have mentioned other plate amps that put out a thousand watts, but I go to check them out and it turns out they don't sell to individuals. I forgot the names of the companies that I am referring to. I'm not interested in the cheapo Dayton "1,000 watt" amp either. I like plate amps because they are designed for the task at hand (subsonic filters, class D, and some have DSP built in).
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post #62 of 68
3/17/13 at 11:18am
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...Or I could scrap this whole setup, sell the subs on Craigslist, and go buy a JL Audio Fathom 12" and it wouldn't cost a penny more than what I would be spending on this headache. It's fun to a point and I'm past that point. There are too many "what ifs" and this could all sound horrible when I'm finished.
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post #63 of 68
3/17/13 at 1:23pm
The JBL subs are way better than JL Audio and having two 15s will deliver far better results. In fact, there are no better 15" sub drivers around! In post #12 I suggested a quiet amp, Yamaha P7000S, that doesn't have any fan noise. Cheaper and better for the task at hand than the Emotiva. Buy some flat pack boxes from Erich - DIY Soundgroup - and you are there.

Still, if you want to give up the JBLs send them to me wink.gif
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post #64 of 68
3/17/13 at 2:33pm
"...Or I could scrap this whole setup, sell the subs on Craigslist, and go buy a JL Audio Fathom 12" and it wouldn't cost a penny more than what I would be spending on this headache. It's fun to a point and I'm past that point."

sorry to hear that you are frustrated.

here are three models to consider:

1. jl audio 12" with 1500 watts in 1.75 cubic foot enclosure (i'm not even sure if the f112 is that big, but let's go with it anyway). dark blue line.

2. 2 x jbl w15gti powered with 650 watts per driver in 4 cubic feet sealed enclosures. orange line. 500 watts per driver would reduce output by about 1db, so not much. you can find plate amps with built in eq that do 500 watts into 4 ohms.

3. 2 x jbl w15gti powered with 1000 watts per driver in 6 cubic feet ported enclosures tuned to 20hz. light blue line. you could use plate amps on these too, 500 watts each reduces spl by about 3db, which is significant, but simplifies things and still provides good performance.

each of these options takes the driver to xmax, but not past. the ported would need a high pass filter.

as you can see, the jl sub will output a healthy 104db at 20hz. however, a dual ported w15gti setup would absolutely slaughter it at 120db at 20hz

the dual ported jbl subs would also have less distortion at every listening level, help smooth room modes, and cost much less money.

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post #65 of 68
3/18/13 at 6:21pm
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Thanks, Antripodean and LTD02. I am sticking with a sealed design. Room gain should help compensate for the low end. I know I'm giving up free output but I am afraid of these things getting too boomy. If I run 1,000 watts to each speaker in a sealed configuration, I would also need a highpass filter. Do they make stand alone highpass filters? I can use the Audyssey control on my Marantz 6006 to do a little EQ on the low end. Can you think of any reasonably priced 500-1,000 watt monblock amps? My main concern is reliability. If a plate amp goes bad or doesn't sound good, I have to make a new enclosure. If a monoblock amp goes bad, I just replace it. My uncle builds custom furniture and he will be helping make this box look pretty. I only want to do this once. I don't want to bother him too much.
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post #66 of 68
3/18/13 at 10:46pm
I wouldn't worry too much about reliability with proamps, because they are made to take abuse, I recommend balance minidsp for eq and high pass, very easy to use. Since you r doing seal a hp is not necessary but eq is. Inuke 6000dsp is ideal in your situation.
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post #67 of 68
3/19/13 at 8:10am
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Datranz, like LTD02 pointed out, anything over 650 watts will require a high pass filter even if it is sealed.
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post #68 of 68
3/28/13 at 6:50pm
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A local dealer mentioned the Crown CDi series of amplifiers. They tried to obtain the JL Audio amp used to drive their in-wall subs but JL responded with a no and no. They claim that their amps are heavily equalized and cannot be used with any other subwoofer. I think that most of this equalization would happen after installation but what do I know.

The Crown CDi series uses a weird phoenix input and has a barrier strip rather than binding posts which I am not a fan of. Speaking of fans, it has a setting that allows it to come on at a lower tempurature but at a lower speed which is nice but I am really curious as to how loud these fans are when the amp gets really hot. Aside from that, it seems to be a pretty capable amp with all the power, eq, and crossovers I need.
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