Sealed Infinity Kappa Perfect VQ

[Guiria]

I sent a PM out to Wmax and TLS Guy about sealed kappa perfects. Perhaps the info will be useful to others.

Originally Posted by Guiria
I didn't want to hijack GTHill's thread so I figured a PM would do. Hope you don't mind.

Originally Posted by WmAx View Post
Yes, it would be sufficient. However, for HT use, the ported system is superior by far. In music, it is not likely much content under 35Hz will be present, so it does not matter. But for HT - with 20Hz range LFE being common - the ported system will have far better performance.

-Chris

I realize the ported version, when executed correctly is superior, however I'm pretty sure I don't have WAF for 5.5 ^3 ft box in my family room.

Ideally I want to end up with 2 12" subs @ 2^3 ft each or close to that size.

I listen to movies 95% of the time at between -15 to -20 db's reference. After reading about Avaserfi's build I'm not sure I want a sub that plays that low in my current situation(which is multi-use family room with 3 kids that sleep down the hall). I don't want my kids to be vibrated off their beds at night I am exploring the following options.

2 12" rythmik audio servo sub kits
2 12" kappa perfect VQ
The dual 12" Emotiva sub setup

I would think the 2 DIY setups would be superior to the Emotiva, however I like the footprint of those subs and they spec'd from Emotiva to play significant levels at 20 Hz.

I'd like to do something similar but using sealed given the same footprint. If I'm not listening at reference then EQ'ing in the low end would allow me to get reasonable extension out of sealed right?

Thanks in advance

 

[Guiria]

Answer from TLS Guy

For your situation my sealed alignment for the Kappa 12 VQ no insert will be perfect.

http://forums.audioholics.com/forums...9&postcount=25

It's only 1.25 cu. ft and if you brace them and build them well, they will be just fine for you. Completely fill the inside with Polyfill but do not compress it.

Have you downloaded the pdf.for that sub? If not please do, and get touch for any questions.

Don't forget to add the volume of the driver, the bracing and amp to Vb. I would get an amp with EQ. In your situation you will be listening at lower volumes, and adding + 12db per octave below 30 Hz will be well worthwhile. You will not exceed xmax of two of those subs in your situation.

May be you want to post your question and my reply to the thread. Hopefully it is useful to others as well.
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[Guiria]

Answer from WmAx:

The Emotiva must use EQ to get flat 20Hz response. The same is true for the Kappa Perfect if you use it in a sealed alignment. It is highly doubtful that the Emotiva uses equal quality drivers to the Kappa Perfects simply due to cost. Their subs would likely cost far more as a finished product if they had to use drivers of that grade.

The Behringer DCX2496 is the ultimate subwoofer manipulation tool and crossover. It will allow you to precisely control the response of the subs and subjective 'tightness' along with powerful crossovers. Ideally, you can use the DCX to control two subs, the left main channel, right main channel and center channel for ideal integration of the system. Of course, to use it on the main channels, this would presume you have outboard amp for the main channels so you can insert the DCX between pre-amp signal and amplifier input.

The Perfect 12VQ, using the mid Q motor alignment option, will have approximately -3dB response at 34 Hz and -6dB response at 27Hz in a box that was externally, about 16" cubed, built with 3/4" thick material, yielding roughly a 2 ft^3 internal volume net. That is fairly small. This Kappa Perfect while being passive, will outperform the Velodyne DD-12, and nearly equal the DD-15 in distortion vs. SPL and maximum output levels, based on 3rd party credible measurements that have been performed on these systems(even though the perfect was given huge disadvantages such as an under powered amplifier in these tests that began to clip at higher SPL testing, and even though the Velodyne units were high servo feedback designs that are supposed to have superior performance).

-Chris
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Dedicated to improving the real[quantifiable] parameters of sound reproduction.

 

[Guiria]

Is the Behringer DCX2496 an absolute if using the kappa perfect sub? The regular BFD is a lot cheaper and would do the job of equalizing the sub and putting a 12db/octave boost at 30 Hz.

I realize the BFD isn't quite the same machine as the DCX2496 but I guess the question is will I use the features of the DCX or just end up using it as a parametric eq.

If the BFD is not sufficient then please let me know. I think you can get 2 channels with 12 frequencies so using one unit with 2 subs would be sufficient. Do people actually use all 24 frequencies when EQ'ing subwoofers?

 

[Matt34]

A bit off topic but I just wanted to add my two scents. I have planned to add a pair of sealed Perfects using a couple of boxes from PartExpress as stereo subs for my towers but frankly, the technical aspect of the Behringer DCX2496 seems a bit over my head.

If I do go through with this Chris is going to get a ton of noob questions from me.

 

[WmAx]

A bit off topic but I just wanted to add my two scents. I have planned to add a pair of sealed Perfects using a couple of boxes from PartExpress as stereo subs for my towers but frankly, the technical aspect of the Behringer DCX2496 seems a bit over my head.

If I do go through with this Chris is going to get a ton of noob questions from me.

Matt, I'll be glad to help you with setting the equipment up. Just PM me when you have questions. Hopefully, you are using separate amp for the mains so you can use the DCX to it's potential and route both the subs and mains through it.

If it's just for music, sealed units will be...... perfect(pun intended - ). If for HT also, though, ported will be ideal(and you can do ported with no compromise to SQ if you are using a DCX as a controller).

-Chris

 

[WmAx]

Is the Behringer DCX2496 an absolute if using the kappa perfect sub? The regular BFD is a lot cheaper and would do the job of equalizing the sub and putting a 12db/octave boost at 30 Hz.

I realize the BFD isn't quite the same machine as the DCX2496 but I guess the question is will I use the features of the DCX or just end up using it as a parametric eq.

If the BFD is not sufficient then please let me know. I think you can get 2 channels with 12 frequencies so using one unit with 2 subs would be sufficient. Do people actually use all 24 frequencies when EQ'ing subwoofers?

The BFD is sufficient for EQ control/room correction/LF compensation. But if this is supposed to the ultimate subwoofer system, then the DCX is going to give you more ability to tune/achieve ideal response and integration. For optimal xover/routing of your mains and subwoofer, they would ideally both be run through the DCX.. If you are using a receiver's built in xover abilities, it will have far less flexibility in crossover, and far less precision in so far as optimal setting for integration. The DCX also has additional filter types for EQ use that go a long way towards sound customization(shelving filters and bandpass filters). However, the vast majority of surround sound receivers have no way to apply external effects to signals it is amplifying. If you use pre-outs of the receiver to send to DCX, there is no way to send the signal back into the amplifiers directly. You would have to use external amp for the mains in this case.

-Chris

 

[mike c]

how much is an infinty kappa perfect over there in the US? any links to online sites?

 

[WmAx]

how much is an infinty kappa perfect over there in the US? any links to online sites?

Best price from reputable retailer I know at the moment is $139.99 + shipping for the 10" version and $159.99 + shipping for the 12" version.

10" : http://www.sonicelectronix.com/item_7816_Infinity+Kappa+Perfect+10+VQ.html

12" : http://www.sonicelectronix.com/item_7817_Infinity+Kappa+Perfect+12+VQ.html

I don't know if their is an economically feasible way to ship them to the Philippines from the USA. It would probably cost the amount of the item itself just for shipping.

-Chris

 

[mike c]

Best price from reputable retailer I know at the moment is $139.99 + shipping for the 10" version and $159.99 + shipping for the 12" version.

10" : http://www.sonicelectronix.com/item_7816_Infinity+Kappa+Perfect+10+VQ.html

12" : http://www.sonicelectronix.com/item_7817_Infinity+Kappa+Perfect+12+VQ.html

I don't know if their is an economically feasible way to ship them to the Philippines from the USA. It would probably cost the amount of the item itself just for shipping.

-Chris

thanks! those are pretty affordable!
i actually have a US address for big packages (small ones are not cost efficient)

i figure a lot order for these drivers = savings on total shipping cost.

how low can you tune these guys for decent output without exceeding xmax?

i figure a Behringer EP2500 can power four ported 12's ?

 

[Matt34]

Matt, I'll be glad to help you with setting the equipment up. Just PM me when you have questions. Hopefully, you are using separate amp for the mains so you can use the DCX to it's potential and route both the subs and mains through it.

If it's just for music, sealed units will be...... perfect(pun intended - ). If for HT also, though, ported will be ideal(and you can do ported with no compromise to SQ if you are using a DCX as a controller).

-Chris

I'll be using a separate amp and keeping my HSU's for LFE in movies.

how much is an infinty kappa perfect over there in the US? any links to online sites?

Edit: Chris found way better prices than my quick google search did.

 

[WmAx]

thanks! those are pretty affordable!
i actually have a US address for big packages (small ones are not cost efficient)

i figure a lot order for these drivers = savings on total shipping cost.

how low can you tune these guys for decent output without exceeding xmax?

The absolute linear x-max(where the magnetic circuit acts as a near perfect linear device) is about 14mm. But they can be used in the low 20mm one way excursion range without mechanical failure, but the motor becomes non-linear at this range.

Considering this, you can tune the 12" version in the appropriate volume cabinet to around 14-15Hz F3 without issue, with some compromise in maximum output SPL around 20-30Hz range. I usually recommend an 18Hz-20Hz tuning frequency for best size compromise vs. performance, and slightly higher output SPL around the 20-30Hz range. And remember, a port that will not compress the LF output substantially has to be pretty significant(35+ square inch cross section area minimum), making a large folded slot port the only feasible option for porting, if maximum ability is so desired.

-Chris

 

[Guiria]

Relativity

The BFD is sufficient for EQ control/room correction/LF compensation. But if this is supposed to the ultimate subwoofer system, then the DCX is going to give you more ability to tune/achieve ideal response and integration. For optimal xover/routing of your mains and subwoofer, they would ideally both be run through the DCX.. If you are using a receiver's built in xover abilities, it will have far less flexibility in crossover, and far less precision in so far as optimal setting for integration. The DCX also has additional filter types for EQ use that go a long way towards sound customization(shelving filters and bandpass filters). However, the vast majority of surround sound receivers have no way to apply external effects to signals it is amplifying. If you use pre-outs of the receiver to send to DCX, there is no way to send the signal back into the amplifiers directly. You would have to use external amp for the mains in this case.

-Chris

I'm pretty sure we are on two completely different playing fields when it comes to sound. The DCX sounds awesome in its ability to tailor sound, and I would consider one down the road. If I build the pair of kappa perfects I will be upgrading from a single 10" 150 watt subwoofer that does not play lower than 26 Hz(in room response). My room is 2280 ^3 ft and I have heard / recognize the limitations of my current sub.

I guess my ramblings are to make the point of relativity. Coming from an underpowered sub in an oversized room for that sub, I think the sealed 2 12" perfects with a BFD would blow me away. Are they the ultimate system? Probably not. Will they give me years of listening enjoyment? I will gamble and say yes.

When the time comes when I have a dedicated HT room and a couple of 5^3 ft boxes in there is no big deal, then a new build will be necessary.

 

[Guiria]

Just a public thanks to WmAx for the information regarding these subs. I'm heavily considering a kappa perfect setup over a dual 12" rythmik audio setup.

 

[Guiria]

WmAx,

Will you point me to the third party measurements of the kappa perfect vs. the DD-12

After looking at those specs on the DD-12 I've got to see this for myself.

Thanks,

 

[WmAx]

I guess my ramblings are to make the point of relativity. Coming from an underpowered sub in an oversized room for that sub, I think the sealed 2 12" perfects with a BFD would blow me away. Are they the ultimate system? Probably not. Will they give me years of listening enjoyment? I will gamble and say yes.

When the time comes when I have a dedicated HT room and a couple of 5^3 ft boxes in there is no big deal, then a new build will be necessary.

Just food for thought: In a typical size room - corner loaded - a single 12VQ in the recomended slot port enclosure will easily produce in-room SPL of 110dB range at 20Hz. The sealed version, practically, would be limited to barely over 100dB in the same circumstances. Again, for music, it's not a big deal, at over 35Hz, response would be similar for both, but for HT, and if you like to run your sub hot for movies like some do, the added LF output ability is a big deal.

-Chris

 

[mike c]

kappa 12
no EQ
http://www.hometheatershack.com/forums/subwoofer-tests/978-diy-infinity-kappa-perfect-12-a.html

kappa12
with EQ
http://www.hometheatershack.com/forums/subwoofer-tests/979-diy-infinity-kappa-perfect-12-w-eq-xo.html

DD12
http://www.avtalk.co.uk/forum/index.php?t=msg&th=18355&start=0&rid=14&SQ=1147288566

 

[WmAx]

WmAx,

Will you point me to the third party measurements of the kappa perfect vs. the DD-12

After looking at those specs on the DD-12 I've got to see this for myself.

Thanks,

http://forums.audioholics.com/forums/showpost.php?p=231850&postcount=16

Note 1: This is the Kappa Perfect 12.1. The version without the variable motor. The VQ version will be comparable - both have nearly identical parameters and design - except for the variable motor design on the VQ that allows you to adapt it ideally to ANY type of enclosure system.

Note 2: The Kappa Perfect measured, was in a small sealed box, and it was powered by an UNDER-POWERED amp not even rated for the impedance of the Kappa Perfect in bridged mode that it was being used. So, clipping distortion is very likely showing up in these measurements on the Kappa in the 100dB plot. Please be aware, that the Kappa is outputting about 2-3dB higher output in the 100dB plot at under 30Hz, as compared to the DD-12. The way these plots are done, they establish a reference SPL at a higher frequency, and you have to manually cross-reference actual SPL for each plot. I over laid the plots from the measurement archive of each system for easier viewing - but the manual cross reference of actual SPL must be noted, still.

-Chris

 

[Guiria]

Thanks for those links, very interesting.

You can buy a DD-12 on ebay for 1700.00

I've calculated for 2 kappa perfects start to finish would be around 900 using:

EP2500 - 350
BFD - 100
2 kappa perfect 12VQ - 360
box & finishing materials - The rest

Guess I better start saving...

 

[WmAx]

kappa 12
no EQ
http://www.hometheatershack.com/forums/subwoofer-tests/978-diy-infinity-kappa-perfect-12-a.html

kappa12
with EQ
http://www.hometheatershack.com/forums/subwoofer-tests/979-diy-infinity-kappa-perfect-12-w-eq-xo.html

DD12
http://www.avtalk.co.uk/forum/index.php?t=msg&th=18355&start=0&rid=14&SQ=1147288566

You can see that the amp is really clipping hard when they try to use the EQ to boost output. Folks: you must use VERY high powered amps when you try to boost LF output on a sealed system. That was not a well done EQ compensation system by any means, nor did the DIYer have a clue of the requirements of power for the application.

-Chris