Infinity kappa perfect 12vq DIY

[cobblepots]

Hello all,
I'm currently building this design:

http://forums.audioholics.com/forums/showthread.php?t=45528

It will be powered by an ep2500. I feel like this amplifier is overkill. However the ep1500 isn't cheap enough for me to justify the difference. Do any of you have better recomendations?

There is a lot of discussion in the thread about a few points:

1. They recomend OC705 or 8lb Rock wool. Both are hard to get for me but I've found a source for OC705. It's a bit expensive however. Does anyone have any ideas on a better/cheaper/more easily sourced material?

2. The designer recomends the DCX2496 to act as a digital crossover. He recomends a second order highpass filter at 20Hz to protect the subwoofer from frequencies below that level. This unit is also a bit too expensive for my tastes. I will be buying the UMC-1 from emotiva when I get my Statements finished. This unit has a balanced subwoofer output. I am still a bit new to the game and have been unable to determine if the emotiva will allow me to set both a high pass and low pass filter and at what levels. Basically, do I need the DCX2496?

Thanks!

[ThomasW]

Hi,

1)The idea of needing a DCX2496 simply for a sub is preposterous. The sub out from the prepro is fine.

2) OC705 is cool stuff, but you can do the same thing with regular old R-13 fiberglass batting from a big box store. Understand OC705 is simply regular fiberglass that's been compressed and formed into a thinner semi-ridged panel.

3) No you don't need a EP2500 for that woofer, but as you've noticed the price difference is such that it's a better long term investment if/when you upgrade to a bigger driver

IMO 20Hz tuning is ok for chamber music, but it's not practical for anything else. So yes a high-pass would be necessary to protect the driver from the low frequency sound effects in soundtracks and the low frequency music recorded on many newer CD's

BTW how far along are you on this project?

[Dennis H]

Fluffy fiberglass insulation will work fine. You can do like he said and wrap it in cloth if you're worried about loose fibers.

The Emotiva will handle the crossover but a subsonic filter would still be useful.

Edit: Thomas beat me to it.

[cobblepots]

Thanks for the quick replys!

I think I will go with the EP2500 and the emotiva pre/pro. I actually do have experience with the pressed fiberglass boards, I was just worried about the glass particles in the air. I suppose wrapping it in cloth from walmart will work.

What sort of sub-sonic filter would you recomend?

With regards to the project:
I'm building a Statements setup with 2 monitors, 2 mini's and the center. All three have the cabinets ready for drivers. The subwoofer has all the wood cut out but not glued together. I only have 14 clamps, not enough to do everything! I'm ordering the crossover components tonight along with the drivers from parts express. I'm hoping to get as much done as possible the next two weeks because that's when my advanced course starts here at GE. There goes 20 hours of free time a week...

I'm still working on the finishing ideas but I've come up with some good thoughts:

I want to cover the speakers and sub with a makore veneer (paper backed) I will be using tung oil or lineseed depending on how the test swatches turn out. I will be using whipe on poly over the oil. The tops and bottoms of the speakers will have caps on them that are like the av123 Rockets. I really like that look. I know, piano finish is impossible. I'll probably be finishing this speakers until december. Though I hope not!

[littlesaint]

I've been using the eQ.2 from Elemantal Designs and it works well. It's all analog, 2 parametric EQs and a highpass filter. No measurement capabilities, but for $99 it pretty much covers what you need for a subwoofer.

[Hdale85]

Probably going to be waiting for a while longer still for those pre/pro's from emotiva. I was waiting forever and ended up just grabbing a cheaper receiver that takes L-PCM over HDMI so I have something for the time being. When they finally come out I'll probably sell my receiver and get one of the Emotiva units.

[ThomasW]

Have you built the enclosure for the sub? Have you purchased the Infinity driver?

[cobblepots]

The enclosure is all cut out. Tonight I plan on starting with the port. The Infinity woofer will be at my door on Monday.

[ThomasW]

A single 12" driver sub tuned to 20Hz is a rather odd match for the Statements when used in a home theater situation.

Are you limited by budget, placement or something else to using only one of these drivers?

Oh and FWIW ported subs are not cannons, they don't blow fiberglass into the room.

[Hdale85]

Why did you pick the Infiniti driver anyways? Kind of an odd choice for a DIY

[cobblepots]

Well, a lot of other DIY websites really like the driver as it has great, low distortion capabilities. I also like the look of the aluminum cone. It was stated that the output was comparable to the PB13-ultra. I have heard this sub in person and absolutely LOVED it. The begining scene in Monstars Inc where they blow up the sock.... Felt my hair move yet it was tight and not boomy at all. Hopefully mine will sound similar and with the integration settings on the emotiva (if that ever gets finished) I will have a winner. But we'll see...

The subwoofer design was well documented and measured which was a huge plus for me. I don't have time to design my own at the moment and won't for at least the next 30 weeks. This after hours course work is taking up a ton of my free time.

[Hdale85]

Ok. Well I hope you like it How much was the driver? The reason I said it was strange because there are probably other drivers that could easily out perform it. The Dayton subs are very very nice I'll probably end up going with 2 15" Dayton HO subs as they are pretty inexpensive but offer great sound and lots of output.

[ThomasW]

We have a bit of experience with an older version of the 12" Infinity Kappa Perfect (1400 watt published power handling). Here's how issues with it were solved after someone without a high-pass filter decided to 'test' the claimed power handing with a 600 watt amp...

http://www.htguide.com/forum/showthread.php4?t=9542&page=1&pp=35

Notice the pretty omega symbol embossed in the cone... 8O



You might consider adding a second sub if you want output levels that are a better match for the rest of the system.....

[Hdale85]

Wow thats awesome

[cobblepots]

Ouch! Now I'm a bit scared... I have done a bit of research on this speaker though. The new model has been updated from what I understand and the folks over at Audiohaulics seem to have had no problems driving it with the rated power. In fact many stand by it being able to run more than it's rated power and past it's stated max throw. I will be running a sub sonic filter on it at 20Hz; hopefully this will help protect it. I thought that with the Mini Statements a good cross over point would be around 70Hz using the UMC-1's crossover function. The output of this subwoofer has been measured to be 110-120dB in this range without distortion. Maybe I'm lost in my lack of knowledge here... Am I completely off base? Well too late to turn back now though but any extra help would be most appreciated.

The driver cost me 150 after shipping. It's not terribly expensive. I am limited by budget mostly. This whole setup is basically consuming my entire signing bonus from GE. There's always something else to buy, something else to make them look a bit better, something else to make them sound better...

[Hdale85]

Well you probably could have gotten a Dayton HO 15" sub for about that and extended a down into the sub 20hz range pretty easily without any issues. But what matters most is that your happy when its all done. Thats what DIY is all about.

[ThomasW]

The output of this subwoofer has been measured to be 110-120dB in this range without distortion.

I seriously doubt that claim, along with the one in the thread where they "measured 120dB output at 20Hz at a distance of 2m from the driver."

Please understand I'm not saying it's not a bad driver. It just has a fairly limited Xmax and IMO should be used in multiples for HT..

[Hdale85]

Not to mention that driver is really aimed at car audio. It may do 120db at 20hz in a car but probably not in an HT.

[cobblepots]

Thanks for your replys everyone. Every time I return to my desk I have another post to respond too. This redesigned high pressure turbine blade is getting the back burner for the moment... I completely understand where everyone is coming from. Both sides claim to be experts... However, I trust Thomas's judgement more than most. I've been a long lurker of these boards and have always found your posts to be very informative and backed up by a lot of experience. The driver is the VQ version which is supposedly an updated and improved version. We will find out! For the moment, I could never turn up the subwoofer to even make 110 db in my current living situation. My neighboors in my townhome complex would have me evicted very quickly. :twisted:

The subwoofer setup is an temporary one anyways. I plan on only having it for a few years as this setup will be an upgradable one. When I get my own house/condo I will add the full sized Statements for my mains and shift the others arround to create a 7 channel setup. By then I will have a pair of stereo subwoofers, either a second infinity or something bigger! That is also why I am going with Emotiva as they have a great upgrade policy. Do you honestly feel that I am not going to get good sound out of this setup?

[ThomasW]

Do you honestly feel that I am not going to get good sound out of this setup?

The system will sound fine. You just don't have the optimal output match between the mains and a sub with a single 12 driver.

But as you've said, a townhouse isn't the best place to test these things.... :B

[cobblepots]

Well I'm certain it'll be a step up over my 10" logitech. Altough my roomate does not understand why I want such massive speakers as he believes our current setup is sufficient. Little does he know! Gotta match his Sony XBR52's coolness factor...

[Dennis H]

That ought to be a decent match to the Statement monitors with their single 7" woofer as long as you get that highpass filter in there. As you expand the system with a bigger room and bigger mains, you can always add more subs.

[mayhem13]

For starters, below 18hz excursion will be way off the charts so some sort oh subsonics control/highpass will be essential in this design. As for using the DCX, the call is yours but it does have expansion capabilities for multiple sub use in HT. As for limited excursion capabilities, 18 mm xmax doesn't seem to limited for a twelve inch driver compared to most 12 inch subs out there. As for drivers manufactured for Autos not being Ok for HT, that's rediculous. The drivers T/S params should suggest its capabilities for suitable HT alignments such as sealed,ported and PR. The design doesn't state which Pole piece was used but given the volume, i would say no insert selected and when modeled in a ported alignment as suggested will take no more than 500w peak without xmax being achieved between 24 and 30hz, way above the enclosures tuning freqency. In sealed enclosure however around .7 Q, this driver will easily take 800w and better for +115db output. So if you do build it, be carefull with the ep2500 and you must get some sort of subsonic control but otherwise, this driver will make an excellent HT sub.

[ThomasW]

As for drivers manufactured for Autos not being Ok for HT, that's rediculous.

Did anyone in this thread made a generic statement about ALL car audio drivers being bad for HT?

Nope.....

As for limited excursion capabilities, 18 mm xmax doesn't seem to limited for a twelve inch driver compared to most 12 inch subs out there

We prefer drivers like the Shiva-X, it costs less money than the Infinity and offers 27mm of Xmax

In sealed enclosure however around .7 Q, this driver will easily take 800w and better for +115db output.

Sure if you want a 'sub' with the passband of a woofer....

Finally, who wants a 20Hz Fb when the fun stuff for HT is 15Hz or lower?....

[Hdale85]

I believe what I said was that this particular driver is more suited towards car audio. Smaller space needs less power less xmax and above all else less output because there is a lot of gain from the cabin. My new towers I'm building will play down to and possibly below 30hz quite well a 20hz tune sure isn't adding much to the mix for me. Sure his setup probably is quite a bit different but I'm just giving an example of why the sub is not optimal.

[mayhem13]

Sorry, wasn't advocating a .7 q box-just stating that if you have calories to burn, it can take em. I've used the Shiva too but i just can't wrap my head around such a big box and as for 27mm xmax, i can only imagine the non-linearities that go on in that stroke. I was only trying to fortify the OPs decision on using this driver for it does make a very capable HT sub although had he posted before he bought it, i would have suggested as RSS390 or two. Excuse the misunderstanding. I'll go lick my wounds now.

[cobblepots]

Thanks for all the comments guys. I do plan on getting the elemental designs eQ.2 for use as a subsonic filter. Would I run into problems with a cross-over point at 15Hz? Should I just put the infinity up on craigslist and get something else??? I'm a bit worried about this now. I do not want to go above a 12" driver because I just can't see it being useful to me at this point in time given my living situation. Would a Dayton titanic have been a better choice? Shoot, here I thought I had it all figured out... I guess that's all part of the learning process!

[Hdale85]

No he told you the better choice Although not sure it will work in the sub enclosure you have planned out. Have you started cutting? And why won't a 15" be ok with your living situation? They will both play loud but a 15" will go a bit lower and have some extra punch there. Honestly if you can have a 12 I'd say you can have a 15 and if you have to turn the volume down :B. Honestly if you want to keep what you have its all good like I said before we all just want you to be happy

http://www.diycable.com/main/product_info.php?cPath=24_93&products_id=653

[cobblepots]

Well since I the driver shipped as of yesterday, I think I'll stick with what I have for now. If I don't like it after a while, I'll just upgrade it I suppose.

Would I be alright having the sub-sonic frequency set to 15Hz? Would this cause the woofer to bottom out at say, 400-500 Watts? What Db level Should I expect to get with this setting?

It's funny, the guys on that forum swear by that subwoofer... We'll see. Maybe we'll all be pleasantly surprised! I'll keep everyone updated.

Does anyone have thoughts about the Makore veneer and the gloss black tops? I'm thinking 1/2 inch top and bottom caps for the monitors and center with the bases on the minis also having the bottoms done in black. The mini's will have a 1/2 top. I'm thinking of having is stick out by 3/8 in the front with a 1/2 roundover along the top edge. The front will be rounded over as wel with the 1/2 in. I think the grills will be 1/2" thick with the same roundover applied to the sides. I think this will tie together well. Any thoughts?

[Hdale85]

Well the guys on that forum may have different goals? Although I can't imagine it being any different A long throw sub woofer can still have incredibly low distortion regardless of what a lot of people believe.

As for the finish sounds nice to me.

[ThomasW]

Would I be alright having the sub-sonic frequency set to 15Hz?

That's too low. The filter needs to be around 18-19Hz.

It's funny, the guys on that forum swear by that subwoofer...

Again different people have different expectations. Usually HT subs are tuned lower to take advantage of the special effects stuff (explosions, etc.) these are typically 15Hz or so, and designed to shake the room.

Does anyone have thoughts about the Makore veneer

Don't know what that is..?

[cobblepots]

I'll try it at 18 and see what happens. I think that will be good enough for now.

The veneer I would like to use is a block mottled makore. An example is on this website

http://www.maxxhorn.com/index.php/MaxxHorn-Veneer-Gallery.html

Has anyone had experience finishing it? I think I would like to use a tung or linseed oil on it with a semi gloss or high gloss poly on top of it. I'm going to do samples before I actually cover the speakers of course. Does anyone think the grain will have difficulty bending around the 3/4" round over?

[Haoleb]

First, I would like to introduce myself by saying that I am the first person to have completed the design in question here. I built a pair of these for my 2 channel system. I am powering them with a QSC RMX1450 bridged to each sub and also using the DCX2496 to crossover and EQ the subwoofer response as well as integrate them with my other speakers.

Secondly, I'd like to say that alot of the comments I have read here are way off base. It is a shame that a few members seem to have instantly dismissed this design because it uses "car subwoofers" and becasue they havent heard of it before. You might think I am biased because I have already spent a considerably amount of time and money building them. Really I couldnt care less what someone who hasnt the slightest clue thinks. I dont build my system to impress other people. That being said...

The main goal of this design is low distortion, clean, accurate output. If your trying to win decibel drags then your not going to be happy with this design. Even though it does offer substantial output, I have INFACT measured 120db output at what should be right at 23hz from around 12' away. (using a 30-20hz sweep) The last time I did 20hz sine wave I did infact overheat the VC on one of my drivers enough to smell it so I havent tried to see what kind of output I can achieve again at 20hz with the SPL meter. A number doesnt change how pleased I am with them...

Adressing a few points here:

If you really want to get optimal performance the DCX is really reccomended. This enables you to employ the proper filters and you can accuratly EQ the response. This is an extremely versatile unit. With the standard filters you get lower response but if you wanted the sub to sound sealed there is another filter you can put into place for a tighter sound, at the expense loosing some LF response.

I do not reccomend lowering the highpass filter to 15hz, It is there to prevent the driver from distortion caused by over excursion at low frequencies. This is not a brick wall filter you will still get info below 20hz but of course there are other designs out that will play deeper.

As far as the Ep2500, you made a smart choice to get this. I found it did not really have enough power for those times when I just wanted more, But it is still more than capable of running a pair of these subs. I have had the clip lights come on with my QSC amps which are supposed to put out 1.4KW at 4ohms when bridged. Optimistic I think, But my AC voltage starts to sag too much when pushing the subs to be certain.

Polyfill is not suitable for what this subwoofer was deisgned to do. Use the reccomended OC705 or the rockwool.

[---k---]

Most of the comments were focus on the Tempest and Shiva offering better performance at lower prices. Not that the design you used is a poor one.

I think that if you were to build another sub to compare this one directly to, your opinions may change.

[cjd]

Secondly, I'd like to say that alot of the comments I have read here are way off base. It is a shame that a few members seem to have instantly dismissed this design because it uses "car subwoofers" and becasue they havent heard of it before. You might think I am biased because I have already spent a considerably amount of time and money building them. Really I couldnt care less what someone who hasnt the slightest clue thinks. I dont build my system to impress other people. That being said...

I did not hear anyone saying this - reviewing the thread, the only people that seem to hear "it's bad, it uses a car subwoofer" are.. um...well, two of you. The rest just say that this particular driver choice has its compromises, which include frequency extension and total SPL capability before self-destructing. No comments on distortion (no data to back up arguments either way), nothing else... These issues take on a totally different nature in a car, but that's irrelevant to this discussion.

So, right now, you just seem like a fanboy defending a product that hasn't even been criticised in a way to suggest your defense is even needed. But only with this little bit.

Beyond that, your comments are right on and echo what most everyone here has been saying: it's not going to be huge on SPL if your'e pushing it really hard before hitting its limits, and it needs the higher rumble filter for safety.

I'd be curious to see some distortion data on this driver too if it's out there.

[ThomasW]

Hi Brandon and welcome to HT-Guide...

I'd like to say that alot of the comments I have read here are way off base. It is a shame that a few members seem to have instantly dismissed this design because it uses "car subwoofers" and becasue they havent heard of it before.

It's usually a good idea to read what's written as opposed to projecting into the thread.

No one dismissed the design simply because it uses a car audio driver. People using the forum's search engine will find numerous designs using 'car' audio drivers.

You might think I am biased because I have already spent a considerably amount of time and money building them.

People will read your post and draw they're own conclusions about this....

Really I couldnt care less what someone who hasnt the slightest clue thinks.

Reactionary statements indicate an emotional investment in the subject matter.

The main goal of this design is low distortion, clean, accurate output.

That's the fundamental goal of all designs. And that's the specific reason we recommended using the Shiva-X (actually the Tempest-X ) over the infinity Kappa.

If your trying to win decibel drags then your not going to be happy with this design. Even though it does offer substantial output, I have INFACT measured 120db output at what should be right at 23hz from around 12' away. (using a 30-20hz sweep) The last time I did 20hz sine wave I did infact overheat the VC on one of my drivers enough to smell it so I havent tried to see what kind of output I can achieve again at 20hz with the SPL meter. A number doesnt change how pleased I am with them...

When used in the same box the lower cost the Shiva-X will play louder than the Infinity Kappa

If you really want to get optimal performance the DCX is really reccomended. This enables you to employ the proper filters and you can accuratly EQ the response.

There's nothing unique to the DCX requiring it's use over other and lower cost options.

I do not reccomend lowering the highpass filter to 15hz, It is there to prevent the driver from distortion caused by over excursion at low frequencies. This is not a brick wall filter you will still get info below 20hz but of course there are other designs out that will play deeper.

Some posting in this thread have been designing and building subwoofers for more than 35yrs. This means we have a working knowledge of hi-pass filters and how they should be used.

Polyfill is not suitable for what this subwoofer was deisgned to do. Use the reccomended OC705 or the rockwool.

Prior to this statement there's been no mention of polyfill in this thread.

In conclusion, we happy, you're happy with your build. That said, were we investing $1000+, there are other avenues we'd pursue. The resulting project would play louder, much lower, and have less distortion than Andrew's 1st time design...

Regards,
ThomasW

[Haoleb]

You guys can call it however you see it. I saw this thread, saw some of the comments based on mere assumptions and had to reply.

And, Obviously, I dont need psychiatric evaluations based on what is said in my posts, Nor were the comments about the filters directed at the people around here who undoubtly already know what they are doing.

[---k---]

I would assume that there was a reason the OP asked his questions here, rather than at Audioholics where the design was posted.

[cjd]

You guys can call it however you see it. I saw this thread, saw some of the comments based on mere assumptions and had to reply.

And, Obviously, I dont need psychiatric evaluations based on what is said in my posts, Nor were the comments about the filters directed at the people around here who undoubtly already know what they are doing.

first part: your mere assumptions? Seems that way to me. Obviously not to you or you wouldn't have posted. But as Thomas observed, you were the ONLY person to talk about polyfill, so at some level you sure seem to have made some gross assumptions about the direction the topic may have gone, rather than reading the posts, most of which I suspect you'd agree with. In the long run, conversation about assumptions never gets you far at all - simply posting your data, observations, thoughts, suggestions, and allowing discussions to follow, is far more effective.

Insulting folks at random or in general ("Really I couldnt care less what someone who hasnt the slightest clue thinks.") doesn't tend to go over well, EVER. Very few of the people posting in this thread fall into that category, if any at all.

One other point/question - I think you were talking about lowering the filter to 15Hz for THIS DESIGN not in general?

And, there's a reason Thomas has "curmudgeon in training" in his sig. Most of us have gotten used to his personality and he's a great guy, but can be off-putting at first. Don't let that get to you.

I run 4x Tempest-X with a 3000cu/ft "box" into a ~1200cu/ft room, because I'm looking for frequency extension (~8Hz) and low distortion (the XBL motor really is superb, especially paired with this alignment). I had different drivers previously that were low distortion due to alignment, but clearly not motor design and didn't do 16Hz well without clear mucking elsewhere...

C

[Haoleb]

I'd say that posts 17 and 18 are based on mostly assumptions. I see it everywhere, someone who had never had any experience with something raving on about either how good or bad it is. And it bugs me because there is already enough hearsay to weed through. The OP was already thinking of ditching his DIY based on the comments of people who have never even seen or heard this design in action. I try to refrain from commenting on things that I have not heard nor have experience with.

Perhaps it came off as insulting, which was not the intention. Such is life with the internet. But no, I really dont care. I wanted to try and make clear that I am not another fanboy "ooh look at me I have the greatest subwoofers in the world and they can kill anything" So if someone says they are shit i dont run home crying second guessing myself.

Yes, I was mistaken about the polyfill, I had read the OP question about substituting and thought I had seen polyfill mentioned here.

As for lowering the 20hz filter, I am talking about only this design. I know nothing of some of the other popular designs and cannot comment on them. You will not loose a ton of extension with the 20hz filter in place which is why I do not reccomend lowering it.

[cjd]

So, in the end, I think your objection is... um. what? That alternative drivers that might offer more performance (shall we say, louder to the same frequency extension) were offered up? That different electronics options/opinions were raised?

Post 17 makes no mention of anything other than technical specifications vs SPL capability - 120dB@2M@20Hz = gobs of excursion (well, ok, tuned to 20Hz you damp that a LOT... hmmm.) As such, to reach a given SPL while maintaining low distortion (you can pick up tons as you near limits of excursion steady state - not sure on the motor design so I don't know how linear BL is, and a great many other things) multiples are recommended for HT. Not that they're NOT recommend, nothing at all about them being car audio drivers...

Post 18 simply suggests that cabin gain is sometimes assumed on these numbers... is the driver NOT designed with car audio in mind? Regardless, nothing that I see there suggests it's bad for HT, though dougie does seem to suggest that indirectly through the posts, so ok. I'll give ya that. But, you might notice, others rather dampen that opinion too, before you came along.

I've not pushed my Tempests to 120dB at 2M, but they're moving an awful LOT - that's 4 of them with tons of power behind them... 114dB was where I decided it wasn't worth messing with....

[cjd]

See post 20 by the way... "will it sound bad?" "it'll sound fine, just not go as loud as your mains"

[Haoleb]

My objection was commenting on the performance without ever testing or even hearing the design. All I said were two sentences stating that. Thank you and Goodnight!

[Hdale85]

Well I was pointing out that it might be better suited to car audio applications not that it would be bad in anything other then though. Also you can look at the specs of a driver and determine how its going to work without listening to it or testing it.

[mayhem13]

Take a look at some measurements

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