Simple 12" Infinity Kappa VQ MidQ Plans

[WmAx]

2nd order roll off starting at 20Hz is fine for the subsonic filter. This will prevent over-excursion under the port tuning frequency.

-Chris

 

[Guiria]

so did you end up using the fmod? i got an email from them and at 20hz they are only -3db. is that sufficient?

I did use a single Fmod 20 Hz filter plugged in right at the receiver. As far as I can tell, it's working. See the attachment of my in-room measured frequency response of the sub. It looks like a pretty steep roll off to me although I haven't taken the time to calculate the slope and see if it's 36 db/octave.

 

[T2T]

Shameless plug ...

I thought I was going to build this box, but realized it's too big for where I'd place it. Instead, I'm going for an IB system and have already purchased the new drivers for that install.

I now have a 12" Infinity Kappa Perfect VQ (with *2* 4 Ohm voice coils) available. The mid-Q pole piece has been installed. I don't have the other 2 pole pieces - I'm the 2nd owner.

If you live in the Wash DC Metro, Northern VA area, I want to sell this driver for $80.00. I won't ship it as I've tossed the box.

E-Mail Me

 

[armstrr]

I did use a single Fmod 20 Hz filter plugged in right at the receiver. As far as I can tell, it's working. See the attachment of my in-room measured frequency response of the sub. It looks like a pretty steep roll off to me although I haven't taken the time to calculate the slope and see if it's 36 db/octave.

what are you using to drive the sub(s), an ep2500? i ask because i have read that the sub output from consumer receivers might be a little low to drive the ep.

 

[Guiria]

what are you using to drive the sub(s), an ep2500? i ask because i have read that the sub output from consumer receivers might be a little low to drive the ep.

I'm using a Peavey CS400X which is 600 watts bridged at 4 ohms. It is another pro amp. I think it works well although the fan is pretty loud (relative to no fan at all). Eventually I'm hoping this amp ends up in a closet, however, so I am living with the noise for now.

 

[ras123]

I am pretty new to this speaker setup and building thing. Right now I am in the process of completing by speaker setup, I built a set of SEAS 3 way mains and run some old bose junk for the rears for now until I build the rears as well. I am going to build this sub and use the EP 2500 for the amp. I become confused with this cross over DCX 2496 setup. I have read the entire post and from what I think I am understanding I would have to run my pre-amp out to the dcx2496 using a conversion cable for the rca out my simple receiver has. form there to the EP2500 and then of course to the sub. my setup right now is pretty simple, is there any other way to have a crossover for this sub that is less expensive. I guess the DCX2496 intimidates me in that it is a ~350 cross over for the sub since I do not run seperates for my mains i understand that is all it would control. Is there a simplier way to handle this for now until I upgrade later, the last thing I want is to damage the sub.

 

[alexwakelin]

I am pretty new to this speaker setup and building thing. Right now I am in the process of completing by speaker setup, I built a set of SEAS 3 way mains and run some old bose junk for the rears for now until I build the rears as well. I am going to build this sub and use the EP 2500 for the amp. I become confused with this cross over DCX 2496 setup. I have read the entire post and from what I think I am understanding I would have to run my pre-amp out to the dcx2496 using a conversion cable for the rca out my simple receiver has. form there to the EP2500 and then of course to the sub. my setup right now is pretty simple, is there any other way to have a crossover for this sub that is less expensive. I guess the DCX2496 intimidates me in that it is a ~350 cross over for the sub since I do not run seperates for my mains i understand that is all it would control. Is there a simplier way to handle this for now until I upgrade later, the last thing I want is to damage the sub.

What receiver are you using? You can use your receiver to set the crossover frequency and connect the subwoofer output from your receiver to the EP2500. You would still need a way to convert the RCA output on the receiver to an XLR connection which I believe is what the EP2500 uses for inputs. Many home theater receivers have too low of an output level to drive pro amplifiers, so you can use something like the ART cleanbox. The cleanbox accepts RCA inputs, and boosts the signal and ouputs via XLR, so you are solving two problems with one unit.

http://www.sweetwater.com/store/detail/CleanBox/

You will also need something to filter out frequencies below ~20Hz to avoid damaging the subwoofer. I'm currently using the Harrison Labs 20Hz F Mod.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=266-246

I'm not sure if this is the best device for this purpost, but I haven't blown up my sub (yet).

 

[ras123]

the receiver is a simple onkyo sr605. Thanks for the info, would the fmod go into the receiver pre amp out or after the clean box?

 

[alexwakelin]

the receiver is a simple onkyo sr605. Thanks for the info, would the fmod go into the receiver pre amp out or after the clean box?

The fmod uses an rca connection, so you would have an rca cable going from the subwoofer output into the fmod. Then plug the fmod into the cleanbox. The cleanbox outputs via XLR which you would plug into the EP2500.

 

[armstrr]

does anyone have an extra 20hz highpass harrisons lab fmod they want to sell? they come in pairs and i'll only need one... otherwise i'll buy a pair and have an extra one to sell.

 

[Guiria]

The fmod uses an rca connection, so you would have an rca cable going from the subwoofer output into the fmod. Then plug the fmod into the cleanbox. The cleanbox outputs via XLR which you would plug into the EP2500.

I read somewhere, I think on the Harrison Labs website that the fmod should point towards the reciever, so I plugged mine into the receiver then attached the RCA cable to my BFD. I don't know if it matters, but that is another option for connecting the fmod.

 

[alexwakelin]

I read somewhere, I think on the Harrison Labs website that the fmod should point towards the reciever, so I plugged mine into the receiver then attached the RCA cable to my BFD. I don't know if it matters, but that is another option for connecting the fmod.

On this page, they show the the fmod plugging into the amp.

http://www.hlabs.com/technical/crossovers/

FMODS AND ATTENUATORS MUST "POINT" TOWARDS THE AMPLIFIER- MALE RCA> AMP

 

[lsiberian]

does anyone have an extra 20hz highpass harrisons lab fmod they want to sell? they come in pairs and i'll only need one... otherwise i'll buy a pair and have an extra one to sell.

See the classifieds area a guy is sell one there I think.

 

[lsiberian]

Shameless plug ...

I thought I was going to build this box, but realized it's too big for where I'd place it. Instead, I'm going for an IB system and have already purchased the new drivers for that install.

I now have a 12" Infinity Kappa Perfect VQ (with *2* 4 Ohm voice coils) available. The mid-Q pole piece has been installed. I don't have the other 2 pole pieces - I'm the 2nd owner.

If you live in the Wash DC Metro, Northern VA area, I want to sell this driver for $80.00. I won't ship it as I've tossed the box.

E-Mail Me

You know you could always wrap it up real good or even have the UPS store wrap it for you. at 80 dollars it should instantly sell.

 

[T2T]

You know you could always wrap it up real good or even have the UPS store wrap it for you. at 80 dollars it should instantly sell.

Thanks. After more careful measuring and even more careful analysis of what I'd use instead of this sub (pair of IB subs in an IB install), it's looking more and more like I'm might come back over to the dark side and do this build.

... I'll just noodle in an IB build in my basement for some augmentation bass, as needed.

 

[armstrr]

See the classifieds area a guy is sell one there I think.

couldn't find it...

 

[lsiberian]

couldn't find it...

http://forums.audioholics.com/forums/showthread.php?t=52663

I read this forum way too much lol.

 

[Guiria]

On this page, they show the the fmod plugging into the amp.

http://www.hlabs.com/technical/crossovers/

I stand corrected. I will plug the Fmod in between my receiver and BFD pointing at the amp, or should it be after the BFD? Or does it even matter? Hmmm...

 

[annunaki]

I stand corrected. I will plug the Fmod in between my receiver and BFD pointing at the amp, or should it be after the BFD? Or does it even matter? Hmmm...

Typically, it plugs directly into the amplifier. Depending upon your cables used, this may or may not be an option.

If you are using all RCA cables, then plug it into the amplifier. If not, put it in line with the last RCA connection.

 

[Guiria]

Typically, it plugs directly into the amplifier. Depending upon your cables used, this may or may not be an option.

If you are using all RCA cables, then plug it into the amplifier. If not, put it in line with the last RCA connection.

I use DIY 1/4" plug cables for my BFD to amp connection. In fact I use a DIY RCA to 1/4" plug cable from my receiver to the BFD. I'll have to resort back to a standard RCA cable with the Fmod and then an RCA - 1/4" converter on the end. Sheesh, that plug is going to be six inches long by the time I'm done with it