Haoleb's Kappa Perfect 12vq MidQ Build Thread

[Haoleb]

Uau

Those beasts would look even more amazing with another 2 coats of glossy back and 2 or 3 coats of varnish.

At this point you haven't put any wool inside the subs. I take it that the wool is going to be applied through the driver opening. Right?

I didnt want to go with a high gloss finish because the prep work is not good enough to allow for something like that. I spent 2 days only doing prep work on them and pretty much just said screw it thats good enough im tired of this.

The mineral wool is the last thing I am waiting on. Got my spikes installed (teflon tape and all... I mean who does that?) Got my binding posts in, Just hoping that the wool shows up today so I can glue it in, let them air out for a while and get to rockin' I will be putting it in through the hole for the driver, obviously it would have to be cut into smaller peices to fit in there but thats no problem.

 

[Haoleb]

Well....




They definetly sound good. Just off hand and from my memory I think they are tighter than the EP600. And I dont hear a port noise type sound out of them as I did with that..

And secondly. I think i need to get another EP2500. Yes. It still works. (and the new fan makes an astonishing difference) but it DOESNT HAVE ENOUGH POWER I already had the clip light going in a matter of minutes with that song "lollipop"

 

[croseiv]

Wow! I'm very impressed. Great work.

 

[mike c]

Well....




They definetly sound good. Just off hand and from my memory I think they are tighter than the EP600. And I dont hear a port noise type sound out of them as I did with that..

And secondly. I think i need to get another EP2500. Yes. It still works. (and the new fan makes an astonishing difference) but it DOESNT HAVE ENOUGH POWER I already had the clip light going in a matter of minutes with that song "lollipop"

a few clips lights doesn't mean you don't have enough power but it's cheap insurance.

... are you running 4 ohms each channel? (one driver per channel or bridged?)

 

[Haoleb]

Yes one sub per channel.

I was just playing some tones and on 30-20hz tone I had it pretty well up there (in my mind although it wasnt near 120db like andrew got) And the clip light wasnt coming on. But damn... If there was ever anything that could replicate what an earthquake literally sounds like.. These are it I havent even done any calibrating or playing with the EQ yet either. I dont really want to keep making it louder to find out what they can really do because I dont want to break anything.... But lets just say they sure satisfy me

 

[mike c]

http://i14.photobucket.com/albums/a330/superribbit/charts/EP2500-4ohm-061007.jpg

you basically have at least 600+ watts at 1%THD per channel. avaserfi/wmax can chime in if it's necessary (or safe) to add more power ... your next step up with a second EP2500 is bridged 4 ohms

http://i14.photobucket.com/albums/a330/superribbit/charts/EP2500-2ohm-061007.jpg

1600watts at LEAST

 

[WmAx]

http://i14.photobucket.com/albums/a330/superribbit/charts/EP2500-4ohm-061007.jpg

you basically have at least 600+ watts at 1%THD per channel. avaserfi/wmax can chime in if it's necessary (or safe) to add more power ... your next step up with a second EP2500 is bridged 4 ohms

http://i14.photobucket.com/albums/a330/superribbit/charts/EP2500-2ohm-061007.jpg

1600watts at LEAST

It is safe to use bridged mono EP2500s for music. However, to do this safely, you need to engage a high pass protection filter on the subwoofer channel crossovers at 20Hz with a 4th order Butterworth filter. If you don't, then high amplitude signals under the tuning frequency could cause the driver to easily exceed mechanical excursion limits, thus causing potential damage.

Andrew achieved his measured 120dB using a bridged EP2500, btw.

As for sound quality, you can have any type of bass signature you want using these subs with the DCX. You just need to learn which adjustments to use now.

-Chris

 

[Haoleb]

Probably not really necessary to add more power. I dont actually listen to music with the bass up that high.. But hey.. I gotta see what they can do! We've all been there

Heres the last batch of pics and last steps.

Lastnight after giving the paint some time to dry I installed the binding posts. Which I really love by the way. They are very well made, quality feel easy to install, and work great. Although I did have to drill out the holes that are in them to allow for 12 gauge to be soldered on. Got them at parts express. The binding posts and the plate come seperatly.

The screws I got for the driver. They are technically "metal" screws but they were the only thing I could find locally that was not just plain jane steel, and that had pan heads. They are stainless steel and 2 inches long. You wouldnt normally need them that long but remember I had to add in a second peice of plywood on the back to cover my mistake of trying to use those stupid T nuts. Which Im glad I didnt use as these are much much more reliable and I would have never been able to get those T nuts as tight without them coming out. Those screws are IN there. Put my screwgun on the highest clutch setting and slowly torqued them down. I dont plan on ever taking the driver back out again and also dont need any air leaks

Spikes and binding posts installed. I had to unscrew the spikes just a few threads because when tightened all the way down they were buzzing very loudly aginst the T nuts on the bottom. Besides having the teflon tape there for a seal, I think it probably also makes them less likely to vibrate as it creates a better fit. Now the subs make zero self noise at all. I dont even detect any port noise which I was a bit worried about as I did not round over the insides like I should have (and which I reccomend everyone else do) Only when playing the test tones at high volume and my ear in the port I can hear the air but I couldnt just standing in front of them.

The supplied gasket material that came with the drivers was much too small in my mind. I went to lowes and got some weather striping that was grey and pure garbage as just putting your finger on it compresses it all the way. So i went to a local car audio place looking for proper gasket material and they sent me to Ace where I found what I needed, They had two types, The open cell grey crap and this closed cell stuff. I picked up the 3/4 inch because thats what size the flange is on the drivers. This stuff is way better then the stuff infinity provides which is probably better suited for ... I dunno tweeters or something.

One 10' roll will do. I got two because I didnt want to have to go back there again today if for whatever reason I ran out.

I overlapped it a little bit at the seam so that there would be no leaks. (not pictured)

 

[Haoleb]

After putting in the mineral wool, I used 3M "High Strength 90" vs the 77 because I like the way this one comes out as more of a foam than a spray. (this stuff is about 13 bucks a can too) I attached the wool to just the large brace behind the port. It made a huge difference just by sticking my head inside and knocking on the side of the sub (I dont reccomend you do this until the fumes clear out..... Dont ask me how I know ) I then covered it with some left over burlap from my acoustic panel build I did a little over a year ago.

I put a small fan inside blowing out to clear the fumes. I read somewhere that the fumes from silicone can damage the adhesives used on drivers so I wanted to make sure the fumes from this spray adhesive were cleared out good before I installed the driver. Just leaving it in there for 10 minutes did the trick.

Final assembly all done and ready for the hardest part of all... Getting them in place. I had to drag one of them over on the peice of foam i had it resting in and then wrestled with it for a while going like an inch at a time as I coudlnt just pick it up without moving my other speakers and I didnt want to do that. The second sub I had some help with. Much easier with 2 people

Got em in place and all hooked up and ready to rock!

I was really not sure what to expect... was I going to be blown away (literally..)?

Was I going to be depressed because they were boomier than a honda civic?

Were they even going to work at all?!


Well... They are "all that" I think. The only worthy sub i can compare them to is the Axiom EP600 and they are every bit as good as that with having them just thrown in place and no calibrating, no EQ, no crossing them with my mains, Just threw the crossover on 20-80hz and let er' rip. Im using the but18 seting for the 80hz by the way at the moment. (and but24 at 20hz as has been suggested)


Want to say thanks to Andrew and Chris for their efforts with the design and tips along the way and everyone else who chimed in. now I'm gonna get back to playing with these beasts

 

[jinjuku]

Well... They are "all that" I think. The only worthy sub i can compare them to is the Axiom EP600 and they are every bit as good as that with having them just thrown in place and no calibrating, no EQ, no crossing them with my mains, Just threw the crossover on 20-80hz and let er' rip. Im using the but18 seting for the 80hz by the way at the moment. (and but24 at 20hz as has been suggested)


Want to say thanks to Andrew and Chris for their efforts with the design and tips along the way and everyone else who chimed in. now I'm gonna get back to playing with these beasts

Is it that one of your Kappa Perfects are a match for the EP600, or is it that it takes your two Kappa Perfects to match the ep600?

Thanks again for the extensive build documentary...

 

[Haoleb]

Ok...

Tried inverting the polarity...

These things officially kick the *** of that EP600 hands down I cant believe how much of a difference inverting the polarity did. I have never been able to really hear a difference before but now.. Wow.

 

[Matt34]

Very impressive. I wanna see some in-room FR sweeps pronto.

 

[Haoleb]

Speaking of that. I just got the REW up and running and have been playing with it a bit... Heres a couple of 0-100hz

The first one is without any EQ

It appears that there is a 60hz filter on either the DCX or the EP2500. I think i remember reading something in the manual about it. I think its pretty clear I have my work cut out for me in this room. I dont really know what are the most important areas to concentrate on fixing, especially in the higher frequencies. I need to learn some more about this program before I understand fully what it is I am looking at.

Heres's the response after tweaking the EQ on the DCX. This is still with the 24db butterworth filter at 20hz and the 18db butterworth at 80hz.

I dont really know if this is good or not but... whatever. I am very pleased with not only the subs but my entire system. But hopefully this will help me prove the performance of these subs because from another's viewpoint of course I am going to sound biased. I spent hours everyday putting a ton of effort and funds into this project so as you can imagine Im going to be happy with them. But they honestly are quite impressive.

 

[mike c]

try to fix the graph to follow these parameters:
http://www.hometheatershack.com/forums/rew-forum/36-please-read-getting-graphs-ready-post.html

REW faq
http://www.hometheatershack.com/forums/rew-forum/11707-room-eq-wizard-rew-information-index-links-guides-articles-stickies-please-read.html

 

[Haoleb]

I think playing with the REW is just making things worse. Number one I keep looking at all the peaks and nulls in my room which is depressing to say the least

Secondly, I dont really know what im looking at. I mean, I do. But I dont look at say a waterfall graph and go. Oh right there thats my problem

And third, I am not going to start filling my room with bass absorbers and panels all over the place because first of all that stuff costs money. And I wont be in this room for a whole lot longer and the last thing I need is more stuff to take with me when I finally move to the lower48 so its kinda like what can I do about it anyway? Besides tweak the EQ on the DCX a little bit.

anyway, heres a couple more. this time taken with only the subs turned on and no crossovers. This is taken from just above ear height at my listening position which is about 11 feet back from the speakers in one of the most neutral areas in the room when it comes to bass response.. meaning there isint a large boost of bass there vs some of the other areas in the room.

The first is no eq.

This is with some eq... Like I said I dont know if this is considered good or terrible or what but thats what im getting.

I also have a humm/buzz issue I need to track down. I dont think its a ground loop because if I turn off the DCX it stops. If I mute the inputs or the outputs on the DCX it stops or if I turn the volume knobs all the way down on the EP2500 it stops... It also gets quieter every now and then when im playing with the settings on the DCX.

Oh and then theres the waterfall graph, which looks nothing like the ones Im seeing on the HTS forums.. Mine looks more like a tsunami than a waterfall.

 

[WmAx]

The EQed response is actually really good as far as following the target line is concerned.

Also, it looks like you are getting about a F3 around 17Hz, and a F6 around 15Hz.

As for the buzz, does it persist if you physically unplug the source device from the inputs of the DCX? If so, that does sound like a ground loop issue, or else, your source device is wacky.

-Chris

 

[Haoleb]

The EQed response is actually really good as far as following the target line is concerned.

Also, it looks like you are getting about a F3 around 17Hz, and a F6 around 15Hz.

As for the buzz, does it persist if you physically unplug the source device from the inputs of the DCX? If so, that does sound like a ground loop issue, or else, your source device is wacky.

-Chris

No when i unplug the cables from my preamp it stops as well. It may very well be my preamp as I have had a few issues with it concerning this type of noise.

 

[TLS Guy]

I think playing with the REW is just making things worse. Number one I keep looking at all the peaks and nulls in my room which is depressing to say the least

Secondly, I dont really know what im looking at. I mean, I do. But I dont look at say a waterfall graph and go. Oh right there thats my problem

And third, I am not going to start filling my room with bass absorbers and panels all over the place because first of all that stuff costs money. And I wont be in this room for a whole lot longer and the last thing I need is more stuff to take with me when I finally move to the lower48 so its kinda like what can I do about it anyway? Besides tweak the EQ on the DCX a little bit.

anyway, heres a couple more. this time taken with only the subs turned on and no crossovers. This is taken from just above ear height at my listening position which is about 11 feet back from the speakers in one of the most neutral areas in the room when it comes to bass response.. meaning there isint a large boost of bass there vs some of the other areas in the room.

The first is no eq.

This is with some eq... Like I said I dont know if this is considered good or terrible or what but thats what im getting.

I also have a humm/buzz issue I need to track down. I dont think its a ground loop because if I turn off the DCX it stops. If I mute the inputs or the outputs on the DCX it stops or if I turn the volume knobs all the way down on the EP2500 it stops... It also gets quieter every now and then when im playing with the settings on the DCX.

Oh and then theres the waterfall graph, which looks nothing like the ones Im seeing on the HTS forums.. Mine looks more like a tsunami than a waterfall.

For an in room response, that is very good. It will rattle the rafters. Congratulations. I bet your hum is a ground loop.

 

[WmAx]

No when i unplug the cables from my preamp it stops as well. It may very well be my preamp as I have had a few issues with it concerning this type of noise.

Then the first thing to try is an audio isolation transformer. You can even get ones that convert (passively) unbalanced to balanced with RCA to XLRs and all that. A good one seems to run around 50-60 dollars. Here is an example: http://www.artproaudio.com/products.asp?type=90&cat=13&id=106

Note: in cases where your source has high output impedance, some interface issues can occur with a passive device depending on the passive device's load impedance(which is not specified for this product that I noticed). You can use an active converter to insure compatibility even with high source impedance.



-Chris

 

[Haoleb]

I have a cheap set of those RS ground loop isolators I use on my computer. I'll give them a try and if they work I can look into getting some of better quality.


On another note, I brought the Axiom Ep600 back up here to do some side by side comparisons and came to a few conclusions that made me very happy. First and foremost is the issue of a subwoofer's "Self Noise" This is the area where the EP600 pretty much falls flat on its face. Which really I dont like admitting because I have personally heard and have experience with probably more of Axioms lineup than just about anybody and have never really been dissapointed in any of them.

Playing test tones, especially down in the 30-20hz range the EP600 makes soo much port noise that it almost drowns out the bass. I actually thought my audioadvisor catalog was going to get sucked up into the cabinet when I held it over the port. The airspeed coming out of it seems really high.

Playing the EXACT same tone and measuring the EXACT same db level out of my "perfect pair" there is absolutely zero audible self noise. It actually doesnt seem like they are playing as loud even though according to the SPL meter it is exactly the same. And instead of a large fan, the wind feels more like a slight breeze from the port. Its really astonishing how all I can hear out of these subs when playing test tones is... bass. No chuffing nothing vibrating. Its like a black hole that only eminates bass. (although I did notice some faint buzzing that sounds like its coming from the driver on one of the subs at about 25-30hz when i have my ear next to the driver)

Listening to music the most obvious difference I can hear (and feel) is that the VQ's play either cleaner or deeper (im not sure which perhaps both) because the slam feels more solid and the bass notes are more well defined. I actually had a harder time telling the difference between them than I thought I would when I listened to them yesterday and tried to recall how the 600 sounded from memory. I did also mute one of the VQ's to put just a single sub up against the EP600 and achieved virtually identical results.

I havent tried any SPL tests to see which can play louder, Axiom claims 122db in room. None of which even matters to me because of the port noise that It generates. I'll have more to come when I have some more time to evaluate them side by side on various aspects but I am extremely pleased that I actually built these myself and they easily outperform a nearly $1900 well regarded sub. I dont want to come off as this sounding like the EP600 is a peice of crap because its not. far from it. But with that port noise issue, Its a bit like having two cars that are both great in a straight line but one takes the corners like a pro, and the other sends you off into a wall killing you instantly

I'm also going to try and get some video up of what I am talking about for some proof im not just blowing smoke here.