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Post by justinc on Dec 1, 2005 9:03:30 GMT -7
Im looking into doing an IB finally using 8 of the IB15 subwoofers. The room is huge about 50x20x12 since it is open into the kitchen. When modeling it in bassbox it seems that the subs will run out of excursion at 10HZ with only 500watts. I was first considering buying a yamaha p3500s power amplifier to power the system with around 1000-2000watts. However if they run out of excursion at 500w, I think the oaudio amplifier with the 12hz highpass and peq might be a better choice. any comments on either of these amplifiers, or others for this application? thanks
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Post by ThomasW on Dec 1, 2005 12:12:13 GMT -7
If your goal is to reproduce 10Hz sine waves in the kitchen, get a 500 watt amp and have fun.....  John J. says 200 watts/driver, so you might want a larger amp. Sensitivity goes up quite a bit with that many drivers. But power is cheap these days so it's probably better to have too much compared to not enough.... I know of no one running a running rumble filter on their IB. Now that may start changing given the really subsonic stuff people are finding on DVD's like "Batman Returns" and "War of the Worlds" |
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Post by justinc on Dec 1, 2005 12:45:55 GMT -7
well the goal wasnt really to reproduce 10hz sine waves in the kitchen, but I guess that will have to happen if I want them in the living room.  I was more concerned about the fact that they would run out of xmax at 10hz with only 500 watts because I wouldnt want to damage the subwoofers. If Im giving each of them 200watts then an amp like the yamaha p3500s or the ep2500 would be optimal then. How do you avoid overexcursion then in the really low frequency in DVDs such as war of the worlds etc if a rumble filter is not used? It looks like If I give them 200watts each they will reach xmax at about 20hz? and be way over in excursion at 10hz. thanks |
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Post by ThomasW on Dec 1, 2005 13:29:15 GMT -7
So far over excursion issues haven't been a problem. This is partially due to the recommendations of having lots of displacement.
If this starts to become problematic we'll figure out a solution. Unfortunately 'good' outboard subsonic filters aren't readily available. Though I imagine we could get one of our EE friends to design one for us.
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Post by formica on Dec 1, 2005 14:38:27 GMT -7
If this starts to become problematic we'll figure out a solution. Unfortunately 'good' outboard subsonic filters aren't readily available. Though I imagine we could get one of our EE friends to design one for us. I have a feeling that it may come down to that eventually... for driver safety reasons. Most of us have a lot of displacement, but we also tend to have amplifier power to go far beyond the driver's capacity (at those frequencies) as well.  I wonder how complex or pricey building a 5Hz rumble filter would be? I'm in the wrong engineering branch to be of much use here... It's too bad that BFD filters can't be set down to 0-10Hz... as it could have been used to smoothen subsonic response and act as a rumble filter to boot. ROb PS: For the original question... I went with the EP2500 for 6 IB15's ... it's almost the same price as the EP1500 and you never know if/when you upgrade |
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ryans
Full Member
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Post by ryans on Dec 2, 2005 10:01:07 GMT -7
Not too pricy. You'd need a power supply, some quality OpAmps and a few resistors and capacitors to replicate something similar to what's inside the plate amps. I recall some web page for a guy who sold kits like this with simple instructions for various active filters.
I'm running my IB with the default rumble filter in my PE plate amp (Q=0.7, Fb=19.4Hz). But that's mostly because I've just been too busy/lazy to bring it up to work and do the resistor mod. I'm not terribly concerned about sub-20Hz response. Likewise I'm not terribly concerned that I'll run out of excursion. The biggest thing I'd be concerned with is finding some new room rattle or resonance down there that was being masked by the rumble filter. Still, I may drop the filter down to 15Hz or so just for fun.
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lei
New Member
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Post by lei on Dec 8, 2005 15:03:53 GMT -7
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Post by mazeroth on Dec 8, 2005 20:22:14 GMT -7
Gulp. Might be a tad be pricey  |
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Post by qwezxc12 on Dec 9, 2005 10:37:48 GMT -7
Just an FYI:
The Behringer EP series amps have a 5Hz rumble filter built in...
The EP1500 manual, Section 2.3.2, page 6, list the detail of the selectable 50Hz and 30Hz filter. For an IB, I deselected both, of course. But the paragraph goes on to say, " As long as the filter is disengaged, frequencies below 5Hz are cut to prevent damage."
So it sounds like the EP1500/2500 series have another merit point going for them?
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Post by mazeroth on Dec 9, 2005 17:08:54 GMT -7
Very cool, indeed.
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lei
New Member
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Post by lei on Dec 20, 2005 16:16:52 GMT -7
Yes at retail, but not at half price. Much better quality than those professional amps. Gulp. Might be a tad be pricey |
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