Kappa build amp questions

[cicatriz63]

Hey guys, im in the market for a new sub and after stumbling upon this site im fairly certain that DIY is the way to go, especially when my brother has 2 kappa perfects in (wait for it) perfect condition just sitting around not being used. The box itself i think will be pretty straight forward and shouldnt be a problem to get together. The amp side of things is where my brain starts to hurt. Hopefully you guys can clear some things up / give some advice.

First things first, I will only be using one sub (i dont think my brother would like me taking both and not building him one ) and it will be connected to an onkyo sr502 receiver. It will be used for about 70% music 30% movies. Im upgrading from a klipsch ksw-10 which is nearly inaudible even in a small room (listening room is about 12x20x8, have tried it in rooms as small as 10x10 with equally crappy results). Im not really looking for super max spl, just something i can actually hear / feel.

Now my question comes down to which amp to use. Right now im on the fence between the O-audio bash 500 and the ep2500. Obviously the ep2500 is the better choice, but requires more work / $$ to get things going (cables/filters/adapters etc). The noise is another thing im concerned with and i would hate to mod it and void any warranty that it might have.

The O-audio on the other hand from what i can tell is straight forward, run an rca from the preout on the receiver to the amp and then connect to sub and youre done. Its also dead silent. Is this the case? Is there anything else i would need to worry about with this amp aside from making sure the subsonic filter is set properly?

Any advice would be greatly appreciated. Sorry for the long post, just want to get things cleared up before i dive into this. If all goes well I could be starting this build as early as this weekend.

 

[lsiberian]

Hey guys, im in the market for a new sub and after stumbling upon this site im fairly certain that DIY is the way to go, especially when my brother has 2 kappa perfects in (wait for it) perfect condition just sitting around not being used. The box itself i think will be pretty straight forward and shouldnt be a problem to get together. The amp side of things is where my brain starts to hurt. Hopefully you guys can clear some things up / give some advice.

First things first, I will only be using one sub (i dont think my brother would like me taking both and not building him one ) and it will be connected to an onkyo sr502 receiver. It will be used for about 70% music 30% movies. Im upgrading from a klipsch ksw-10 which is nearly inaudible even in a small room (listening room is about 12x20x8, have tried it in rooms as small as 10x10 with equally crappy results). Im not really looking for super max spl, just something i can actually hear / feel.

Now my question comes down to which amp to use. Right now im on the fence between the O-audio bash 500 and the ep2500. Obviously the ep2500 is the better choice, but requires more work / $$ to get things going (cables/filters/adapters etc). The noise is another thing im concerned with and i would hate to mod it and void any warranty that it might have.

The O-audio on the other hand from what i can tell is straight forward, run an rca from the preout on the receiver to the amp and then connect to sub and youre done. Its also dead silent. Is this the case? Is there anything else i would need to worry about with this amp aside from making sure the subsonic filter is set properly?

Any advice would be greatly appreciated. Sorry for the long post, just want to get things cleared up before i dive into this. If all goes well I could be starting this build as early as this weekend.

2 O- Audio 500watt amps cost 450 dollars.

The ep2500 costs around 250.
It doesn't have a subsonic filter though. You can buy a reckhorn b-1 for around 100 though. So your looking at a comparable costs. For more power and a simpler build.

 

[cicatriz63]

2 O- Audio 500watt amps cost 450 dollars.

The ep2500 costs around 250.
It doesn't have a subsonic filter though. You can buy a reckhorn b-1 for around 100 though. So your looking at a comparable costs. For more power and a simpler build.

well like i said only 1 sub would be used, they would never be together.
A simpler build with the ep2500? to me it sounds like the other way around, just plug an rca in the oaudio and be done with it.

I guess basically what it comes down to is is the O audio 500 sufficient enough to push a single kappa perfect 12.1 in the ported enclosure to a reasonably noticeable spl?

 

[adwilk]

I guess basically what it comes down to is is the O audio 500 sufficient enough to push a single kappa perfect 12.1 in the ported enclosure to a reasonably noticeable spl?

Its not the most OPTIMUM configuration, but yes, the plate amp is a much easier configuration and will produce GREAT results.

If you were using both subs, then the ep2500 and dcx2496 or FDP would be ideal.

 

[lsiberian]

well like i said only 1 sub would be used, they would never be together.
A simpler build with the ep2500? to me it sounds like the other way around, just plug an rca in the oaudio and be done with it.

I guess basically what it comes down to is is the O audio 500 sufficient enough to push a single kappa perfect 12.1 in the ported enclosure to a reasonably noticeable spl?

IMO yes, but not everyone will be satisfied. For the 12.1 I suggest you use a 20 hz hpf setting. It's not quite as tough as the VQ. Still it's a very capable sub. I have modeled it so if you want to see the 12.1 in that box look for my model of it. It's in some thread here.

Don't put the sub in the port. YOu will need to extend the back for put it on side. Or you can make a seperate box for it. I would do the later and attach it with a removable fastener to the back of the back. Would give me the option of switching amps later.

Simple is different for many folks. You don't have to build anything extra for the power amp. That's why I go that route with my stuff usually, but to each his own.

 

[WmAx]

Yes, the O Audio 500 is sufficient. The sub, if you build it exactly as specified, will produce more then 2x the SPL of your low quality Klispche unit, and in addition, it will do so with perfect transparent SQ, even at high SPL. The motor used on the Kappa Perfect is of very high quality design.

-Chris

 

[cicatriz63]

thanks for the responses guys, looks likes saturday i go lumber shopping

 

[sawzalot]

thanks for the responses guys, looks likes saturday i go lumber shopping

Be careful when you buy your ply some box stores have a lesser quality birch that is just about one sixteenth less than 3/4 ",this will screw up your cut sheet measurements, bring a tape rule.

 

[cicatriz63]

Be careful when you buy your ply some box stores have a lesser quality birch that is just about one sixteenth less than 3/4 ",this will screw up your cut sheet measurements, bring a tape rule.

Thanks for the heads up. Probably going to pick it up at Lowes, ill be sure to measure it so i dont have to slap somebody around.

 

[fast1]

Be careful when you buy your ply some box stores have a lesser quality birch that is just about one sixteenth less than 3/4 ",this will screw up your cut sheet measurements, bring a tape rule.

thats a really good point

 

[lsiberian]

Thanks for the heads up. Probably going to pick it up at Lowes, ill be sure to measure it so i dont have to slap somebody around.

Please share your build with us. The more details the more help it is to others interested in the hobby.

Measure every part of it. Make sure you get the 13 ply stuff. Sometimes you will need to get it sized down. Andrew made a cutlist for the sub. See it to know what to get and where to have lowe's size it down at. Also I suggest you get a good flush trim router bit. It will make your life much easier.

 

[cicatriz63]

lowes wont be making the cuts
just need them to give me the right wood...will post more once things get under way

 

[lsiberian]

lowes wont be making the cuts
just need them to give me the right wood...will post more once things get under way

on a 4' x 8' you might consider it. Just to make life easier.

I usually buy the 4' x 2' pieces for easy storage. If you can get your wood from a lumber yard you might get a better selection though. Sawz would know about that more than me though.

 

[cicatriz63]

well i ended up having lowes make 3 cuts on the 4x8 which were surprisingly spot on. They also have 2x4 sheets so i saved some money by picking up one of those instead of a whole new sheet.

now i have a question regarding the damping material on the back brace. the plans says 4" on the big brace, i assume that means 4" thick covering the entire brace, is this correct? Also, finding a single 4" peace is hard to find, will 2 sheets of 2" stacked be ok? I would think so but i want to be sure. Finally, will OC703 be comparable to OC705 or the 8lb rockwool? I can get a single 2x4 2" thick sheet for about $20 shipped and is about 15-20 cheaper than the others. Finally, i was thinking about flush mounting the driver, but read that the magnet will press against the material. Will 3" be ok if i decide to go that route or what would some other options be?

So far everything else is going smooth, the port is completely assembled and just need some final touches before the walls are ready. If it continues this smoothley i could have the majority finished by the weekend. Will post some pics once i figure out the site more.

 

[lsiberian]

well i ended up having lowes make 3 cuts on the 4x8 which were surprisingly spot on. They also have 2x4 sheets so i saved some money by picking up one of those instead of a whole new sheet.

now i have a question regarding the damping material on the back brace. the plans says 4" on the big brace, i assume that means 4" thick covering the entire brace, is this correct? Also, finding a single 4" peace is hard to find, will 2 sheets of 2" stacked be ok? I would think so but i want to be sure. Finally, will OC703 be comparable to OC705 or the 8lb rockwool? I can get a single 2x4 2" thick sheet for about $20 shipped and is about 15-20 cheaper than the others. Finally, i was thinking about flush mounting the driver, but read that the magnet will press against the material. Will 3" be ok if i decide to go that route or what would some other options be?

So far everything else is going smooth, the port is completely assembled and just need some final touches before the walls are ready. If it continues this smoothley i could have the majority finished by the weekend. Will post some pics once i figure out the site more.

Cover the entire brace. 703 will probably work fine.

 

[sawzalot]

Glue the two inch material together with spray adhesive then wrap em up with an old cotton sheet like a christmas present works out fine like that.

 

[WmAx]

well i ended up having lowes make 3 cuts on the 4x8 which were surprisingly spot on. They also have 2x4 sheets so i saved some money by picking up one of those instead of a whole new sheet.

now i have a question regarding the damping material on the back brace. the plans says 4" on the big brace, i assume that means 4" thick covering the entire brace, is this correct? Also, finding a single 4" peace is hard to find, will 2 sheets of 2" stacked be ok? I would think so but i want to be sure. Finally, will OC703 be comparable to OC705 or the 8lb rockwool? I can get a single 2x4 2" thick sheet for about $20 shipped and is about 15-20 cheaper than the others. Finally, i was thinking about flush mounting the driver, but read that the magnet will press against the material. Will 3" be ok if i decide to go that route or what would some other options be?

So far everything else is going smooth, the port is completely assembled and just need some final touches before the walls are ready. If it continues this smoothley i could have the majority finished by the weekend. Will post some pics once i figure out the site more.

OC703 is fine. You can simply cut a large hole in the dampening behind the driver so that the driver vent is clear and has a free flow of air. Adhering 2 pieces of 2" together in order to make a 4" piece is fine.

-Chris

 

[cicatriz63]

thanks guys, will be ordering the amp and oc703 tomorrow. should be functional by the weekend. pics to come.