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Well, I dont mean to rain on your parade with the first reply but the XTi1000 will be nowhere near enough power to drive 2 of those in a sealed alignment. It will work but you are going to run out of headroom VERY fast.


I would look at providing EACH driver with about 2000 (real not rated) watts.


Since you are buying a BFD you do not need the eq that the XTi has. I would look for 2 used pro amps like the QSC PLX 2402s that I am using or perhaps one Crown CE4000.


-Eli
 

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My first comment was going to be that a dual RLp-18 was going to require an awfully big box, but looking at your diagram it seems that you are building and awfully big box (what are you shooting for - 16 or so cubic feet?).


You get a lot of SPL per dollar with those drivers, but at the epense of a huge box. For going sealed, I'd probably rather build something like kramskoi's box with dual TC-3000's. you get less SPL, but you also get the same Q with a box only 1/6 the size.
 

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Discussion Starter · #4 ·
I already own the Xti1000 Amp, and I am trying to keep this under $1000, so maybe a bigger amp in the future. Also with 1400 watts to the drivers, I am keeping Cone Displacment under control, more power and it starts to go into the red.


The Box is 16 Cu/Ft total, around 15.1 effective. I have room for this large of box, so going smaller would not really mater.


Thanks
 

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Quote:
Originally Posted by fireanimal /forum/post/0


I already own the Xti1000 Amp, and I am trying to keep this under $1000, so maybe a bigger amp in the future. Also with 1400 watts to the drivers, I am keeping Cone Displacment under control, more power and it starts to go into the red.


The Box is 16 Cu/Ft total, around 15.1 effective. I have room for this large of box, so going smaller would not really mater.


Thanks

How are you getting a "rated" 1400 watts to the drivers with an XTi1000? You could do it to one driver but not both.


-Eli
 

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Discussion Starter · #6 ·
Dual 2 ohm Voice Coil Model. Voice coils wired in series, speakers wired in parallel. Amp Bridged 4 ohm @ 1400 watts. I belive Crown lists RMS ratings.


I am wondering more about my design, and less woried about my amplifier. The amp is external and can be upgraded latter, but I want to make sure the the design is solid first.


Thanks
 

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Quote:
Originally Posted by fireanimal /forum/post/0


Dual 2 ohm Voice Coil Model. Voice coils wired in series, speakers wired in parallel. Amp Bridged 4 ohm @ 1400 watts. I belive Crown lists RMS ratings.


I am wondering more about my design, and less woried about my amplifier. The amp is external and can be upgraded latter, but I want to make sure the the design is solid first.


Thanks

That will be a 2 ohm load and the amp is not stable into that bridged. Even if it was a 4 ohm load it would be 700 "rated" watts PER driver. A good rule of thumb is that real world output will be about 80% of spec.


I know you are concerned about your enclosure but I am pressing this issue. The best driver and enclosure in the world will sound like crap if it has power issues.
 

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Quote:
Originally Posted by fireanimal /forum/post/0


Dual 2 ohm Voice Coil Model. Voice coils wired in series, speakers wired in parallel. Amp Bridged 4 ohm @ 1400 watts. I belive Crown lists RMS ratings.


I am wondering more about my design, and less woried about my amplifier. The amp is external and can be upgraded latter, but I want to make sure the the design is solid first.


Thanks

If you have two 2 ohm DVC subs each wired in series, that gives you two 4 ohm SVCs. Two 4 ohm SVCs in parallel gives you a final 2 ohm nominal resistance. That amp doesn't seem to be capable of 2 ohm bridged operation. You could do 4 ohm stereo, however, giving 500W to each coil (or the equivalent series/series wiring, giving you 8 ohms bridged, 1000W).


Edit: Awww, I was beat to the punch!
 

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Discussion Starter · #9 ·
Yeah I got messed up writting it out, here is what I was thinking. 2-Dual 2 ohm subs each wired to a seperate channel @ 4 ohms 500 watts, or 2-Dual 4 ohm subs bridged at 4 ohms @ 1400 watts.


Those subs are thermally rated at 500-1000 watts. If I went bridged @ 1400 watts x 80% = 1120 watts. I know that I am at the bottom of there rating, but I modeled at 1000 watts, which is 70% of the rated wattage, and the SPL response looks high enough for me.


I appreciate your help on the amp issue, and I relieze that more available, clean power is better, but I am wondering about cone displacement. I am using a large enclosure, which means less air spring inside the box. If it was a smaller sealed sub, there would be more air resistance in the box, and it would take more power to drive the sub to Xmax, but I am already close to Xmax at 1000 watts?


As I said before I am a newbie at this enclosure stuff, so my above reasoning might be way off.


Thanks.
 

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Quote:
Originally Posted by fireanimal /forum/post/0


Yeah I got messed up writting it out, here is what I was thinking. 2-Dual 2 ohm subs each wired to a seperate channel @ 4 ohms 500 watts, or 2-Dual 4 ohm subs bridged at 4 ohms @ 1400 watts.


Those subs are thermally rated at 500-1000 watts. If I went bridged @ 1400 watts x 80% = 1120 watts. I know that I am at the bottom of there rating, but I modeled at 1000 watts, which is 70% of the rated wattage, and the SPL response looks high enough for me.


I appreciate your help on the amp issue, and I relieze that more available, clean power is better, but I am wondering about cone displacement. I am using a large enclosure, which means less air spring inside the box. If it was a smaller sealed sub, there would be more air resistance in the box, and it would take more power to drive the sub to Xmax, but I am already close to Xmax at 1000 watts?


As I said before I am a newbie at this enclosure stuff, so my above reasoning might be way off.


Thanks.

1000 true watts per driver in your speced enclosure looks pretty good. However, you are only going to get half that per driver with your current amp no matter how you wire it. Also remember that EQ down low (which you will need if you want flat response
 

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Discussion Starter · #11 ·
I may have misunderstood the Wattage in Bassbox pro, I assumed that it represented total system wattage at 1000 watts, with the result that I got.


From the way you speak 1000 watts in Bassbox pro is 1000 per driver, is that correct. Because if it is, I understand now why you are saying shy on power.


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It's 1000 watts for the system not each driver, & 6db per octave @ 30hz is what I use, that's not unreasonable for most rooms.



Have a look over here at Scotts thread . If I were working within your budget, I'd consider a 30" dia sonotube under the screen Single RL-p18D4 tuned below 10hz on a BKA1000a4, but you already have an amp.
 
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