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Discussion Starter · #1 ·
I have a pair of infinity kappa perfect 10.1 subs in a sealed box wired up in serial running off a behringer ep2000 amp.

http://www.crutchfield.com/S-Sjy8DFnMz7I/p_108PER101/Infinity-Kappa-Perfect-10-1.html


At 8 ohms, bridged they should be fed around 1000W RMS (according to the manual, which I know over states the case)


Bottom line, the subs don't seem that loud. I have an old 60W home audio sub sitting in the same room that seems to put out more oomph.


What am I doing wrong? Everything seems to be set up correctly. The source is coming from my denon 2312 receiver off the sub preout, RCA to XLR adapter fed into the input to the amp.


I assumed the 2 10s with 1000 watts would be crazy loud... Should I buy a new box with a port? Maybe return the amp and go another direction? Help please!
 

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The Ep1500 can put out 800 watts at 8ohms bridged.

http://www.avsforum.com/t/855865/measuring-amplifiers/0_100#post_10749998

 

Here is the EP2500 which can put out 1300 watts at 8 ohms bridged.

http://www.avsforum.com/t/855865/measuring-amplifiers/0_100#post_10755565

 

The Ep2000 should be somewhere in between. How big is your room? A room and a car is two VERY different sizes, it takes a lot of drivers to pressurize a room compared to a car. Two 10" drivers is not going to put out lots of spl especially in a sealed enclosure (maybe at 40hz and up...). Another possibility is that you are not used to the frequency response of your new subs. Your old sub could have a boomy peaky response which most people are used to
 

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Discussion Starter · #3 ·
I am building a dedicated theater it is 18' long by 13' wide.


However, right now I have a large living room that is open to my kitchen and eat in kitchen with cathedral ceilings... sitting there is a small 60W sub just to make the small surround setup sound reasonable. That is the sub that actually sounds pretty boomy. I set up my two 10s next to it and just moved the input over to the new setup just to make sure it worked. I was surprised at how loud the old sub (which couldn't have cost more than $200) was compared to subs that cost $700 plus a $300 amp.


It will likely by much louder in my theater... but wondering if I should change the box or do something different. The theater is currently studded, with wires being run...
 

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If you bought a pre made box perhaps it is undersized?


The level may not be set properly from the receiver to the amp, you could try boosting it at the receiver.


I would double check every setting on the amp and reciever before running out to buy a ported box.


What 60 watt sub are you comparing to?
 

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Yeah i would check the levels on the receiver.


Receivers and pro amps generally like to see different input levels so you might have to crank up the sub pre out.


There may also be something wrong with the amp, or it may not be bridged properly.


You can also take a look at the manual for the infinity's to see what they recommend for box size.


Edit: Didn't see your last post disregard the receiver levels.
 

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Discussion Starter · #8 ·
I searched around re: preamp output level on consumer receivers to pro amps, the consensus seemed to be that there is no problem there. I am not sure what balanced and unbalanced inputs are, but should I use the input that isn't xlr. not sure what the name of it is...


you can see the jumper settings... I think its all set up right...
 

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I think xlr may be more useful in the pro audio world but i'll have to read up on that myself. I personally haven't touched the xlr in's on my pro amp because the 1/4" inputs we're far more convenient.


Try the 1/4" inputs with an rca to 1/4" connector.
 

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Quote:
Originally Posted by Mik James  /t/1469497/car-subs-for-my-new-theater#post_23234342


I think xlr may be more useful in the pro audio world but i'll have to read up on that myself. I personally haven't touched the xlr in's on my pro amp because the 1/4" inputs we're far more convenient.


Try the 1/4" inputs with an rca to 1/4" connector.
In a perfect world there would be nothing but XLR. 100% of noise issues, be it RFI, EMI or ground loops, can be traced to the use of unbalanced connections. The pro-audio world recognized that circa 1970, adopting a clean sheet of paper philosophy that within a very short time frame virtually eliminated the use of unbalanced connections, starting with the microphones, extending through the signal chain to the power amps. If consumer audio had done the same there would be no "I've got hum" threads.
Quote:
I turned the sub level on the receiver all the way up. I even got the speaker to clip a little bit with the amp gain all the way up. I'm pretty sure its being driven pretty hard..
If you mean that you saw the amp clip indicator light up you are getting adequate input signal. Just don't expect a car sub intended to fill a 200 cubic foot car with sound to fill a 2000 cubic foot room with sound.
 

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Quote:
In a perfect world there would be nothing but XLR. 100% of noise issues, be it RFI, EMI or ground loops, can be traced to the use of unbalanced connections. The pro-audio world recognized that circa 1970, adopting a clean sheet of paper philosophy that within a very short time frame virtually eliminated the use of unbalanced connections, starting with the microphones, extending through the signal chain to the power amps. If consumer audio had done the same there would be no "I've got hum" threads.

+++++++1
Quote:
Just don't expect a car sub intended to fill a 200 cubic foot car with sound to fill a 2000 cubic foot room with sound.

The above statement does not hold true for all car subs
 

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Quote:
Originally Posted by braveheart123  /t/1469497/car-subs-for-my-new-theater#post_23235654


The above statement does not hold true for all car subs
Perhaps not for all auto sound sub drivers, but pretty much for all auto sound subs, which rely on cabin gain for response below 60Hz or so, and since they have that cabin gain they can work in very small enclosures. Those drivers might provide adequate output in a larger room where cabin gain is a non factor, as with the OPs room, but that means a much larger box than what his drivers are currently in.
 

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Quote:
I have a pair of infinity kappa perfect 10.1 subs in a sealed box wired up in serial running off a behringer ep2000 amp.

Those kappas are ridiculously sensitive at 93dB. If I were you, I'd go ported with them in an HT setup and room your size.
 

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Quote:
Originally Posted by braveheart123  /t/1469497/car-subs-for-my-new-theater#post_23235864


Those kappas are ridiculously sensitive at 93dB.
They would be if that spec was honest, but it isn't. Actual sensitivity at 1 watt is 84dB, at 2.83v (2 watts) 87dB.


It actually models pretty well in 1.3 cu ft (net) vented tuned to 27Hz, but the required 32 inch long 4" round port will take the size up quite a bit. In just about any size sealed cab f3 won't be lower than 50Hz, which is perfect in the intended auto sound application, but it just doesn't cut it for HT.
 

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Quote:
In a perfect world there would be nothing but XLR. 100% of noise issues, be it RFI, EMI or ground loops, can be traced to the use of unbalanced connections. The pro-audio world recognized that circa 1970, adopting a clean sheet of paper philosophy that within a very short time frame virtually eliminated the use of unbalanced connections, starting with the microphones, extending through the signal chain to the power amps. If consumer audio had done the same there would be no "I've got hum" threads.

I wonder why they didn't? Cost?


I think the op recognizes that 2 10's in a 2 cube sealed box aren't going to be as good as a massive 15" or 18" Subwoofer. The bigger issue here is there seems to be more more output coming from an 8" 60 watt ported sub than the sealed 10's.


I've modeled an 8 inch infinity with 60 watts in 1 cu ft and 2 cu ft ported boxes and while it was possible to surpass the output of the sealed 10's 2 cu ft, (the 10's had 300 watts before excursion) it only happened at 50hz by a db or 2 with a high tune and very peaky response.


Granted that was an 8 inch car sub so grain of salt, perhaps the op's 60w 8 inch is more effecient and has noticeably more output at 50 hz than the Infinity Beta 8 i modeled.


Still those 2 10's should be kicking the crap out of that ported 8" below 40hz.


Edit: It actually looks like the 8" ported could get near the performance at 40 hz as well in a 1.5 ft box but thats with a 5db peak and it's down 10db from the sealed at 30hz and a hipass filter lowers the 8's by a couple db as well.
 

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Quote:
They would be if that spec was honest, but it isn't. Actual sensitivity at 1 watt is 84dB, at 2.83v (2 watts) 87dB

oops...my bad! my eyes drooled looking at the 90+ dB sensitivity in the listed t/s specs in the useer manual. Didnt read the 2.83v
 

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Here is a simulation of your 2 drivers in a sealed enclosure. I don't know what the dimensions of the enclosure you are using so I just guessed 1.5cu ft.

 



 

That is with 700 watts and xmax is reached at 20hz. The Ep2000 will power it perfectly fine. If you have a SPL meter you can check what kind of levels you are getting nearfield. A quick way to see what kind of voltage you are getting from the lfe output of the receiver is to use a multimeter. Set the receiver to 0db (whatever reference is) and play a 60hz sine wave through the receiver, measure the A/C  voltage on the lfe output. Make sure all speakers are disconnected!

 

These drivers model pretty good in a ported enclosure tuned to 25hz with 1000 watts. If you don't plan to buy new drivers I would go with a ported enclosure to give you the most spl.

 
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