DIY Music (non-HT) subwoofer conundrum

[Headfoot]

Hello everyone,
I've been narrowing my plans for a subwoofer used in a hi-fi stereo setup. What I need is great sound (very low distortion) flatness of sound (not too much of an increase at any particular Hz) and of course it needs to go at least relatively loud . My priorities of course though are quality of reproduction.

Once choice is a Infinity Kappa Perfect 12" in a small (80-120L) sealed enclosure. I have a previous thread here if you would like to look at this one further. http://forums.audioholics.com/forums/showthread.php?p=343187#post343187

One of my original concerns was price, but now I am able to expand my budget on this project. This lead me to think that perhaps I could make a different sub. After some research I heard a number of good things about a Peerless XLS 12" with a passive radiator for a box of the size I am looking at. Here is a link with a project box relatively similar to what I plan; the T/S parameters for the XLS are there for your knowledge. The only difference is my box will be slightly bigger and I will only use one passive radiator. http://www.geocities.com/adrian_mack/

So here is my issue; I don't want to spend over ~500$ at this point, but I can expand in the future. To be more clear, I currently own a relatively nice Harman Kardon 140w (when bridged) amp I have been running my current subwoofers on passively (it can go down to a 4 ohm load). I would like to build this new sub as an active one, but if I can get a great sub minus the plate amp, and buy that later, that would be great too. The aesthetics of box with an open back doesnt really bother me, so consider that a non-issue.

So when it comes down to a 500$ price point, music as the focus, and future expansion being a possibility, which sub is my best choice?

Thank you for reading, and thanks in advance for any input you can provide.

(PS: I will be running these with 2 ADS L1090's, 6 1/2" Braun woofer version.)

 

[jaxvon]

You can get a single Infinity Kappy 12VQ and a Behringer EP2500 for about $500. Of course, that does not include building materials, but with a proper box (I would recommend a ported enclosure), you will have one heck of a subwoofer. The amp is powerful enough to run two 12VQ subs at sane listening levels.

 

[TLS Guy]

Hello everyone,
I've been narrowing my plans for a subwoofer used in a hi-fi stereo setup. What I need is great sound (very low distortion) flatness of sound (not too much of an increase at any particular Hz) and of course it needs to go at least relatively loud . My priorities of course though are quality of reproduction.

Once choice is a Infinity Kappa Perfect 12" in a small (80-120L) sealed enclosure. I have a previous thread here if you would like to look at this one further. http://forums.audioholics.com/forums/showthread.php?p=343187#post343187

One of my original concerns was price, but now I am able to expand my budget on this project. This lead me to think that perhaps I could make a different sub. After some research I heard a number of good things about a Peerless XLS 12" with a passive radiator for a box of the size I am looking at. Here is a link with a project box relatively similar to what I plan; the T/S parameters for the XLS are there for your knowledge. The only difference is my box will be slightly bigger and I will only use one passive radiator. http://www.geocities.com/adrian_mack/

So here is my issue; I don't want to spend over ~500$ at this point, but I can expand in the future. To be more clear, I currently own a relatively nice Harman Kardon 140w (when bridged) amp I have been running my current subwoofers on passively (it can go down to a 4 ohm load). I would like to build this new sub as an active one, but if I can get a great sub minus the plate amp, and buy that later, that would be great too. The aesthetics of box with an open back doesnt really bother me, so consider that a non-issue.

So when it comes down to a 500$ price point, music as the focus, and future expansion being a possibility, which sub is my best choice?

Thank you for reading, and thanks in advance for any input you can provide.

(PS: I will be running these with 2 ADS L1090's, 6 1/2" Braun woofer version.)

I would use the Infinity Kappa perfect 12, either no insert sealed, or low insert Qts 3.4 in a ported enclosure. Do you need the alignments and graphs?

 

[Headfoot]

Kappa Perfect

Thanks for the help guys!

If its not too much work I would appreciate any and all more information, you can never have enough!

I did find their specifications on Infinity's website along with the graphs and numbers.

I'll probably build this subwoofer in May or June.

Appreciate the help!

 

[haraldo]

Is DIY worth it now?

I'm just wondering about if it's worth the effort to DIY when you can get the AV123 MFW-15 at $600,- or two sub's for $1000...

http://av123.com/index.php?page=shop.product_details&flypage=shop.flypage&product_id=189&category_id=9&manufacturer_id=0&option=com_virtuemart&Itemid=37

Seems like something that's very tough to beat..... even with a DIY project.....
(I know they are not sealed. but still....)

 

[Sheep]

I'm just wondering about if it's worth the effort to DIY when you can get the AV123 MFW-15 at $600,- or two sub's for $1000...

http://av123.com/index.php?page=shop.product_details&flypage=shop.flypage&product_id=189&category_id=9&manufacturer_id=0&option=com_virtuemart&Itemid=37

Seems like something that's very tough to beat..... even with a DIY project.....
(I know they are not sealed. but still....)

A properly built Kappa would put those to shame.

SheepStar

 

[haraldo]

Interesting, Thanks

 

[avaserfi]

The Infinity Kappa VQ is an extraordinarily well designed driver that is matched, much less exceeded, by few in both the DIY and commercial world.

This post might shed more light on the VQ compared to the MFW.

 

[haraldo]

The Infinity Kappa VQ is an extraordinarily well designed driver that is matched, much less exceeded, by few in both the DIY and commercial world.

This post might shed more light on the VQ compared to the MFW.

Looking at it, and some of the specs... I have no doubt whatsoever about that.......

Nice sub, some bracing in there !!!!!

 

[haraldo]

Holy crap and holy mother of.............. (rest is censored)...... Somebody is ripping us off here

I just Checked the prices of the "KAPPA PERFECT 12VQ"
This retails around $800 in Norway (per driver)
And $225 in the US (discounted, per driver)

Some retailrers in Scandinavia obviously haven't heard about the Internet

I know where I'm going to buy my Subwoofer drivers, certainly not locally.....

 

[flippo]

kappa vq

I also built a sub based on the Kappa VQ and I love it!

 

[TLS Guy]

Holy crap and holy mother of.............. (rest is censored)...... Somebody is ripping us off here

I just Checked the prices of the "KAPPA PERFECT 12VQ"
This retails around $800 in Norway (per driver)
And $225 in the US (discounted, per driver)

Some retailrers in Scandinavia obviously haven't heard about the Internet

I know where I'm going to buy my Subwoofer drivers, certainly not locally.....

Yes, but you have to pay taxes for a nanny state, while we run up a deficit protecting you. We should be able to raise protection money from you Europeans. Most of you don't know which end of a gun the bullet comes out of!

 

[haraldo]

Yes, but you have to pay taxes for a nanny state, while we run up a deficit protecting you. We should be able to raise protection money from you Europeans. Most of you don't know which end of a gun the bullet comes out of!

Do you get a kick from annoying people......

 

[Headfoot]

Now the question is about the amp:
I have heard alot of good things about that Behringer, but I would prefer an active subwoofer with a plate amp, as space is a semi-limited factor and I have no where to put a rack. Also I don't need anywhere near that much juice! The current suggestion I have for the Kappa Perfect 12 setup is this one off of PartsExpress http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-806. But at 400$ it will put me over-budget.
Basically a clean plate that will put out 200-400w @ 4 ohms. I don't need obscene amounts of power, as im really looking for quality over volume.

edit:
I saw this on sale also at PartsExpress for a steal at 100$, what I want to know is wheres the catch? http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-805
If it truly can drive up to 240w *cleanly*, then I believe that would be sufficient for my applications; unless I need extra overhead due to the small enclosure?

 

[Sheep]

That wouldn't be enough... WmAx has done some runs with his Kappas and they needed more power then that. You're going to be looking at 400RMS per driver, and at least a 1000peak. I'm going for an EP1500 for my 1 10inch VQ. That's 700RMS, 1500 peak bridged.

SheepStar

 

[WmAx]

Now the question is about the amp:
I have heard alot of good things about that Behringer, but I would prefer an active subwoofer with a plate amp, as space is a semi-limited factor and I have no where to put a rack. Also I don't need anywhere near that much juice! The current suggestion I have for the Kappa Perfect 12 setup is this one off of PartsExpress http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-806. But at 400$ it will put me over-budget.
Basically a clean plate that will put out 200-400w @ 4 ohms. I don't need obscene amounts of power, as im really looking for quality over volume.

edit:
I saw this on sale also at PartsExpress for a steal at 100$, what I want to know is wheres the catch? http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-805
If it truly can drive up to 240w *cleanly*, then I believe that would be sufficient for my applications; unless I need extra overhead due to the small enclosure?

The 500 watt amplifier at your first link would work well, assuming it's power rating is true. The 240 watt amplifier in your next link is not ideal. I tried the Kappa Perfect 12" units on a 325 watt amplifier, and the amp clipped well before the driver operated into a non linear range. I now use a 650 watt amplifier per driver, and it seems to have no problem driving the driver to it's limits.

So, have you made a final decision on the enclosure type? Ported or sealed? It always seems a waste to me to use a sealed enclosure, as this severely reduces the lowest octave output capabilities. But, a proper ported cabinet for this driver is not as easy to build as most would like.

-Chris

 

[haraldo]

The 500 watt amplifier at your first link would work well, assuming it's power rating is true. The 240 watt amplifier in your next link is not ideal. I tried the Kappa Perfect 12" units on a 325 watt amplifier, and the amp clipped well before the driver operated into a non linear range. I now use a 650 watt amplifier per driver, and it seems to have no problem driving the driver to it's limits.

So, have you made a final decision on the enclosure type? Ported or sealed? It always seems a waste to me to use a sealed enclosure, as this severely reduces the lowest octave output capabilities. But, a proper ported cabinet for this driver is not as easy to build as most would like.
-Chris

How much difference on distortion levels in a ported vs. sealed enclosure?

 

[WmAx]

How much difference on distortion levels in a ported vs. sealed enclosure?

This is variable, depending on the specific driver used, and the specific compared sealed and ported enclosure alignments. The increased distortion is caused by the driver having to move the VC a longer distance in the motor path. The motor has less linearity as you move farther out of the motor center, and the same goes for the mechanical suspension systems used by the driver. In addition, the higher power subjected to the voice coil for the sealed variant to reach an equivalent SPL at the lowest octave range aliging with the boost in amplitude provided by the port will cause the voice coil to reach a higher temperature, thus causing the driver to thermally compress more, and causing the physical properties of the driver to shift farther in so far as the electrical T/S parameters, as compared to a lower level signal, causing further dissimilar behavior(s). Of course, if one uses a driver in a sealed system within a window that no audible effects occur, then their is no problem. However, the ported variant will still have a greater potential in comparison.

-Chris

 

[avaserfi]

At the same time it seems that I will likely be using an Infinity Kappa VQ with no insert in a sealed box, 1.5 cubic feet large, while only feeding it 125W and I will still be achieving 97dB at 25Hz as modeled by WinISD 2-meters ground plane. While it is true the amp would clip far before the VQ would, the output required for the near field application would be well within this range, especially once room gain and another sub are accounted for.

I will leave the crazy SPL to my ported 12" VQ .

 

[WmAx]

At the same time it seems that I will likely be using an Infinity Kappa VQ with no insert in a sealed box, 1.5 cubic feet large, while only feeding it 125W and I will still be achieving 97dB at 25Hz as modeled by WinISD 2-meters ground plane. While it is true the amp would clip far before the VQ would, the output required for the near field application would be well within this range, especially once room gain and another sub are accounted for.

I will leave the crazy SPL to my ported 12" VQ .

You seem to (1) leave out the fact for people that you will be using two of these in stereo, for computer speakers [and] (2) you forget the amp you are using outputs 225 watts into 4 ohm loads, and the driver is 4 ohms nominal.

-Chris