Change of plans :D

[Grimfate126]

Hi. Well, i tried to order the XO-12 DVC from torrent audio, but its out of stock, and i simply cannot wait 2 more weeks, so im going for the infinity kappa perfect 12 MidQ.

I have already ordered the amp, a 500 watt O-audio plate amp. However, there is one hesitancy. My box (which i have already cut out) is only 3.25 cubic feet, instead of the 3.9 that is designed by avaserfi. How big of a difference will this make?

Thanks

 

[alexwakelin]

Depends how you tune the box. What size vent does it have? You could get ok performance, but nowhere near what that driver is capable of in the proper box. Here's what I came up with. Depending on the vent in your box, the performance you get may be much worse.

That driver models much flatter, and can hit 18-20 hz in the properly designed enclosure. I don't have specs on hand for the Perfect 12vq, but it's performance is very similar to the 12.1.

 

[Grimfate126]

Depends how you tune the box. What size vent does it have? You could get ok performance, but nowhere near what that driver is capable of in the proper box. Here's what I came up with. Depending on the vent in your box, the performance you get may be much worse.

That driver models much flatter, and can hit 18-20 hz in the properly designed enclosure. I don't have specs on hand for the Perfect 12vq, but it's performance is very similar to the 12.1.

i found the specs, and its different from the 12.1. The way i modeled it, it seems to be the exact curve as the original. However, i get -4 dB at 20 Hz, instead of 2, which is fine with me

what worries me is that, even with a HPF at 20 Hz, the cone exceeds xmax at around 32 Hz. This is at 500 watts.

 

[alexwakelin]

what worries me is that, even with a HPF at 20 Hz, the cone exceeds xmax at around 32 Hz. This is at 500 watts.

I've never directly compared their specs, but others on this board have said they have very similar performance, and are pretty much interchangable in the 12vq plans posted here.

I am seeing the same xmax problem at 500 watts in your 3.25 ft^3 box. I doubt you will hit that with your plate amp though, at 450 watts you are just under xmax.

 

[avaserfi]

I would not recommend such action. You are asking for poor performance from the VQ by putting it in such a cabinet. If you want to use the VQ you should build the proper box for it otherwise you will be limited the drivers capabilities and possibly destroying it in the process.

Also note that the port dimensions are as critical as the total cabinet volume. You never gave the port dimensions within this thread.

 

[Grimfate126]

the port dimensions are 14"x1.5"x35"

i did model it with the new sizes, and it seemed respectable. -6 dB at 20 Hz with the HPF at 20.

i will build another box soon, possibly within a year. The proper one

 

[avaserfi]

There will be a severe limit of the drivers performance due to insufficient cross-section of the port, but it should be okay otherwise.

 

[Grimfate126]

There will be a severe limit of the drivers performance due to insufficient cross-section of the port, but it should be okay otherwise.

im ok with that for now.

how severe are we talking? will i still be able to reach to the low 20s?

 

[avaserfi]

im ok with that for now.

how severe are we talking? will i still be able to reach to the low 20s?

Yes, but not with the extreme SPL the version I posted plans for will.

 

[Grimfate126]

Yes, but not with the extreme SPL the version I posted plans for will.

ok. thankfully i dont plan on pushing this subwoofer. will save it for a later time

 

[pocho]

why not spend another $30 and cut another box?

I think its worth $30+ to get the most from your choice of hardware. go for it! Think about it that plate amp and driver are over 90% of your cost, why hinder the capability of your hardware for another $30 bucks.