plans for sealed sub box for Infinity perfect 12.1

[chris357]

I just thought I woudl ask if anyone had plans for a sealed box to put the 12.1 sub in. I'm about to make the perfect sub boxes but am thinking they are just so huge. I would not mind a box that has a smaller footprint

any sugestions ???

 

[Warpdrv]

Do you already have the driver...?

 

[cicatriz63]

I've been contemplating on doing this myself. I already have the kappa 12.1 in the avaserfi box, and it sounds excellent. The box though is ginormous, and while its not a problem in its current location (basement) I have another 12.1 that I would like to put in a living room and that size just isn't going to cut it. It would be nice to see some model comparisons between a sealed and the ported design. I've realized that I use the ported sub for music alot more than for movies so I don't think losing a little low end extension will be a problem. Hopefully some of the experts can chime in here.

 

[chris357]

Do you already have the driver...?

yes i have two 12.1 drivers, the ep2500 and the dcx i even have the wood I just don't know if i want two 24" boxes in my main living room.

 

[skers_54]

yes i have two 12.1 drivers, the ep2500 and the dcx i even have the wood I just don't know if i want two 24" boxes in my main living room.

In order to use a small, sealed cabinet, a generous amount of EQ needs to be applied. This increases the excursion of the sub at low frequencies. IIRC, the Kappa Perfect reaches its xmax pretty quickly in this configuration, greatly limiting output. If this is for a music-only system, it may not be much of a problem. However, this driver isn't very well-suited for home theater use in a small, sealed box.

 

[chris357]

so for movies this is a bad idea, is there a middle ground?

 

[TLS Guy]

I just thought I woudl ask if anyone had plans for a sealed box to put the 12.1 sub in. I'm about to make the perfect sub boxes but am thinking they are just so huge. I would not mind a box that has a smaller footprint

any sugestions ???

Low Vq vented.

Mid Vq vented.

No insert sealed.

 

[skers_54]

so for movies this is a bad idea, is there a middle ground?

You'd need to model the sub at various enclosure sizes and -3dB points. WinISD is a free program that will let you do this. Otherwise, you could ask wmax for his input since he knows the kappa better than pretty much anyone

Edit: or wait for TLS Guy to do it for you

 

[skers_54]

Low Vq vented.

Mid Vq vented.

No insert sealed.

The OP's sub is the Kappa Perfect 12.1, which is slightly different than the VQ as it doesn't have the variable Q inserts. I think its TS parameters are pretty similar to the Mid Q insert though.

 

[cicatriz63]

here are the exact specs on the 12.1 drivers along with infinity's own (car) models
http://manuals.harman.com/INF/CAR/Boxes and Parameters/KAPPA PERFECT 12-1 Enclosure Sheet.pdf

 

[TLS Guy]

The OP's sub is the Kappa Perfect 12.1, which is slightly different than the VQ as it doesn't have the variable Q inserts. I think its TS parameters are pretty similar to the Mid Q insert though.

That driver is a car thumper.

 

[TLS Guy]

here are the exact specs on the 12.1 drivers along with infinity's own (car) models
http://manuals.harman.com/INF/CAR/Boxes and Parameters/KAPPA PERFECT 12-1 Enclosure Sheet.pdf

Their sealed volume is optimal. That driver does not look like a good home driver, at least in sealed format.

 

[cicatriz63]

Their sealed volume is optimal. That driver does not look like a good home driver, at least in sealed format.

Just out of curiousity, does the 12vq do any better in a sealed box? I noticed the ones you posted earlier were for a ported box. Also just to mention, I have the 12.1 in the ported box and it sounds great, although i dont have a vq to really compare it to. I may consider replacing it though if it is worthwhile.

 

[TLS Guy]

Just out of curiousity, does the 12vq do any better in a sealed box? I noticed the ones you posted earlier were for a ported box. Also just to mention, I have the 12.1 in the ported box and it sounds great, although i dont have a vq to really compare it to. I may consider replacing it though if it is worthwhile.

I did post the sealed alignment it is te third one down. Here it is again.

The Kappa perfect 12 VQ does much better, you need to remove the insert though.

 

[skers_54]

That driver is a car thumper.

Interesting. I thought I remembered WmAx or Andrew saying in one of the Kappa build threads that the 12.1 would work in the VQ box. Just out of curiousity, do you which paramters cause the responses to be so different?

 

[TLS Guy]

Interesting. I thought I remembered WmAx or Andrew saying in one of the Kappa build threads that the 12.1 would work in the VQ box. Just out of curiousity, do you which paramters cause the responses to be so different?

Kappa perfect VQ

Fs = 22.9 Hz
Qms = 10.29
Vas = 96.43 liters
Cms = 0.323 mm/N
Mms = 176.4 g
Rms = 2.398 kg/s
Xmax = 16.75 mm
Xmech = 25.13 mm
P-Dia = 250 mm
Sd = 491 sq.cm
P-Vd = 0.822 liters
--Electrical Parameters--
Qes = 0.79
Re = 4.42 ohms
Le = 1.14 mH
Z = 4 ohms
BL = 11.92 Tm
Pe = 400 watts
--Electromech. Parameters--
Qts = 0.74
no = 0.141 %
1-W SPL = 83.65 dB
2.83-V SPL = 89 dB
Page Two -- Kappa Perfect VQ

Kappa perfect 12.1

Fs = 23.32 Hz
Qms = 10.28
Vas = 83.28 liters
Cms = 0.208 mm/N
Mms = 224 g
Xmax = 14.15 mm
Sd = 531 sq.cm
--Electrical Parameters--
Qes = 0.46
Re = 4 ohms
Le = 3.05 mH
Z = 4 ohms
BL = 16.9 Tm
Pe = 350 watts
--Electromech. Parameters--
Qts = 0.44
2.83-V SPL = 96 dB

Look at Qt and CMS. For a good sealed driver you need a heavy cone and a very floppy suspension.

So you want a high Qts, a highly compliant suspension and low Fs for a good sealed driver.

The best index of compliance is VAS, which is the volume of air with the same "springyness" as the driver suspension. Qt is a combination of electrical and mechanical Q.

You can get an idea of the suitability of a driver for sealed or vented performance by dividing Fs by Qes. The closer the number to 100 more the driver is best used vented. The closer to 50 the more suitable it is for sealed alignment. For sealed the lower the better.

So the kappa VQ no insert is 22.9/0.79 = 29

Kappa perfect 12.1 23.32/0.46 = 50.

So both the above drivers a best in a sealed enclosure, but the VQ no insert is by far the superior driver in a sealed enclosure.

 

[chris357]

shwwoooosh

that was the sound of that going over my head

so, if i am planning on using the 12.1 in a home theater application can I do a sealed box with the 12.1's?

at the time when I bought the drivers.. I thought the 12.1 was the correct one.. i probably wanted to believe it since they were alot cheaper

i could sell them both and probably afford 1 VQ

or stick with what I have and assume that at some point I could upgrade drivers.

if the enclosure would work well with either one..

however the wood is fairly cheap and building new boxes would be fun so I guess it doesnt matter. this coudl be a fun experiment .. except I have no clue as to what the graphs mean.

 

[skers_54]

Kappa perfect VQ

Fs = 22.9 Hz
Qms = 10.29
Vas = 96.43 liters
Cms = 0.323 mm/N
Mms = 176.4 g
Rms = 2.398 kg/s
Xmax = 16.75 mm
Xmech = 25.13 mm
P-Dia = 250 mm
Sd = 491 sq.cm
P-Vd = 0.822 liters
--Electrical Parameters--
Qes = 0.79
Re = 4.42 ohms
Le = 1.14 mH
Z = 4 ohms
BL = 11.92 Tm
Pe = 400 watts
--Electromech. Parameters--
Qts = 0.74
no = 0.141 %
1-W SPL = 83.65 dB
2.83-V SPL = 89 dB
Page Two -- Kappa Perfect VQ

Kappa perfect 12.1

Fs = 23.32 Hz
Qms = 10.28
Vas = 83.28 liters
Cms = 0.208 mm/N
Mms = 224 g
Xmax = 14.15 mm
Sd = 531 sq.cm
--Electrical Parameters--
Qes = 0.46
Re = 4 ohms
Le = 3.05 mH
Z = 4 ohms
BL = 16.9 Tm
Pe = 350 watts
--Electromech. Parameters--
Qts = 0.44
2.83-V SPL = 96 dB

Look at Qt and CMS. For a good sealed driver you need a heavy cone and a very floppy suspension.

So you want a high Qts, a highly compliant suspension and low Fs for a good sealed driver.

The best index of compliance is VAS, which is the volume of air with the same "springyness" as the driver suspension. Qt is a combination of electrical and mechanical Q.

You can get an idea of the suitability of a driver for sealed or vented performance by dividing Fs by Qes. The closer the number to 100 more the driver is best used vented. The closer to 50 the more suitable it is for sealed alignment. For sealed the lower the better.

So the kappa VQ no insert is 22.9/0.79 = 29

Kappa perfect 12.1 23.32/0.46 = 50.

So both the above drivers a best in a sealed enclosure, but the VQ no insert is by far the superior driver in a sealed enclosure.

Thanks! That really helps put some concepts with the numbers!

 

[TLS Guy]

Thanks! That really helps put some concepts with the numbers!

That kappa perfect 12.1 is a really nasty car thumper, and unsuitable for home audio.

You can see that it has a narrow band from 80 Hz to about 150 Hz, to really annoy others at traffic lights. A very evil device indeed!

 

[chris357]

That kappa perfect 12.1 is a really nasty car thumper, and unsuitable for home audio.

You can see that it has a narrow band from 80 Hz to about 150 Hz, to really annoy others at traffic lights. A very evil device indeed!

so if you were me, you woudl sell them and get one kappa vq? build one rather than 2 with that driver?