Sealed DIY questions

[Warpdrv]

^ What he said....

You will need a good amount of amp power, if you decide to get an EQ and bring up the lower end, It will eat up power.

I think I'm going to have to order a couple of those 12W7's for that spectacular upper bass clarity... I love it added in combination with my TC-2000's, now that is bass done right....

 

[WmAx]

^ What he said....

You will need a good amount of amp power, if you decide to get an EQ and bring up the lower end, It will eat up power.

I think I'm going to have to order a couple of those 12W7's for that spectacular upper bass clarity... I love it added in combination with my TC-2000's, now that is bass done right....

You would be better to get pairs of JL 10W7 or 8 W7 for midbass only use.

Also, you must use a proper xover system if you want the highest quality bass integration to properly combine the upper and lower bass units. The DCX2496 of course, is fully appropriate.

-Chris

 

[annunaki]

The Kappa VQ, while superb drivers, are not suited for small sealed enclosures due to their minimal excursion capabilities. Compared to the W7 series drivers they will not be sufficiently capable of withstanding proper equalization to achieve ideal, full range, frequency response. If you want to go with a small sealed build the JL 12W7 would be a great choice. It will have slightly less output than the 13W7, but for the cost difference the added dynamics are negligible. You will want an EP2500 per driver for optimal dynamic range with the W7. Couple this driver/amp combination with a DCX2496 and you will be able to seamlessly integrate your subwoofers with your mains as well as tailor the response to your liking.

If you decide you can go ported the VQ will offer more than enough distortion free output for virtually anyone's needs.

Having had experience with both the 12W7 and 13W7, I can say that the 13W7 is a surprisingly more capable driver so far as output is concerned. One 13W7 is equal to 1.5 12W7's in terms of linear displacement capability. The power capacity is also much greater though.

I agree that there is a big price difference, but the 13W7 is a lot more woofer. It does require a larger enclosure though.

The 12W7 for optimal sealed response and roll-off (.707 Qtc) should be used in a 2.25 ft^3 enclosure.

I totally agree with the DCX2496. I can't wait to get rid of my SVS PB-12Ultra II so I can pick one up and try the 12W7 at it's limits in a sealed enclosure on my own. I am currently running one without eq on the EP2500 and it is already impressive. In the same position as the Ultra was, it is more accurate and definitive even without a paramentric eq to tame my room's 40hz bump in response.

My wife even noticed as it was much more capable at shaking things in the house. She said people three houses away could probably tell we were watching Iron Man. It didn't seem that loud or noticable to me, but then again she was in a different room.

The scariest part is that I am barely working the woofer at this point. I have yet to get the sub to even half of it's rated xmax as it is simply too loud.

 

[jnmfox]

I do want to make some things clear for the OP.

-The Kappa Perfects, in proper ported caibnets, will easily out perform even the 13W7 in the lowest octave, by more than 2x the output, if comparing the JL in a sealed cabinet. The problem is the cabinet system. You can not buy a pre-fabbed cabinet system for this; the port and cabinet have to be custom/specially designed/built to get proper compression free performance from this driver.

-The JL 12W7 is using brute force to make up for lack of proper ported system. It's extreme linear excursion(this is critical/ that excursion is linear - most drivers are no linear) and power handling allow it to make up the small sealed system. You MUST feed about 2000 watts to each driver for this method to work as intended for high dynamic range and distortion free sound.

-The AXIS drivers are incredible, being roughly equivalent to the W7s, but you would be paying much more for the AXIS drivers because you can get W7s about 100 bucks cheaper to begin with (comparing 12" versions of each), and then you have that Microsoft live.com 25 percent discount you can use on top of this. In the end, you could be able to get a 12W7 for about 400 shipped roughly after the live.com cashback.

If you went with a pair of the 12W7 set up as I recommend(dual Ep2500, DCX2496 controller), the total cost for this would be about $1900 USD. The retail F112 JL home version using a 12W7 is over $2000 USD each. So a pair wold be $4000+ and you would have less processing/xover power because the DCX is far more capable then the limited built in processing on the retail units. In addition, you would likey have more actual power/output with the DIY version. It is simply unlikely that the built in JL amps match an EP2500 in real world use. JL amps give power rating in 'shor term dynamic' conditions, please note this. The EP2500 amps provides more power in continous RMS output than the JL Fathom F112 amp provides in short term dynamic. The EP2500's 'dynamic short term' would of course be far higher than the continuous output. The JL 12 W7 can safely hand the Ep2500 with no risk of over heating the voice coil. The W7s have extremely robust design and are among some of the best woofers in the world based upon objective measurement/analysis.

Please note that as wit ANY high powered sub, you need to provide dedicated circuits to them for maximum performance potential. Of course, in real use, you won't likely use but a few tens of watts for music. The only time substantial power is really used is in the occoasional extrme dynamic LF effect in movies and if you purposely turn the subs up to show off.

-Chris

I looked at avaserfi's Kappa build that Haoleb used. Seeing as it is larger than my current sub I doubt I could sneak one of them by my wife...let alone two.

I'll have to see when and how much I get appropriated from the finance committee when the funds come in. I might have to build one then save up to build the second. I would like to keep it around $1,000. If the Emotiva subs deliver what they are claiming that is still an option as well.

I still don't understand using the DCX over the DSP or FBQ?

What is typically involved in providing dedicated circuits? I have an electrician riend who owes me some work for helping him with his PC.

 

[jnmfox]

Having had experience with both the 12W7 and 13W7, I can say that the 13W7 is a surprisingly more capable driver so far as output is concerned. One 13W7 is equal to 1.5 12W7's in terms of linear displacement capability. The power capacity is also much greater though.

I agree that there is a big price difference, but the 13W7 is a lot more woofer. It does require a larger enclosure though.

The 12W7 for optimal sealed response and roll-off (.707 Qtc) should be used in a 2.25 ft^3 enclosure.

I totally agree with the DCX2496. I can't wait to get rid of my SVS PB-12Ultra II so I can pick one up and try the 12W7 at it's limits in a sealed enclosure on my own. I am currently running one without eq on the EP2500 and it is already impressive. In the same position as the Ultra was, it is more accurate and definitive even without a paramentric eq to tame my room's 40hz bump in response.

My wife even noticed as it was much more capable at shaking things in the house. She said people three houses away could probably tell we were watching Iron Man. It didn't seem that loud or noticable to me, but then again she was in a different room.

The scariest part is that I am barely working the woofer at this point. I have yet to get the sub to even half of it's rated xmax as it is simply too loud.

So you are using a 12w7 in a sealed box currently? Just without the DCX?

If I used the pre-fab boxes the 2 ft^3 box should work for the 12w7, right?
Would the 3 ft^3 box work for a 13w7?

 

[annunaki]

So you are using a 12w7 in a sealed box currently? Just without the DCX?

That is correct. With the room gain it plays quite deep and quite loudly to boot

I should mention that my room is 15' x 17' x 8' and open to my kitchen & dining room (both of similar size) as well as my upper level stairway.

If I used the pre-fab boxes the 2 ft^3 box should work for the 12w7, right?
Would the 3 ft^3 box work for a 13w7?

The 2ft^3 PE enclosures will work fine with the 12W7 though they are not up to my standards.

The 3ft^3 PE enclosure would work with the 13W7 as well.

The PE enclosures are made pretty well, but it would definitely not hurt to reinforce them some.

 

[Warpdrv]

Having had experience with both the 12W7 and 13W7, I can say that the 13W7 is a surprisingly more capable driver so far as output is concerned. One 13W7 is equal to 1.5 12W7's in terms of linear displacement capability. The power capacity is also much greater though.

The 12W7 for optimal sealed response and roll-off (.707 Qtc) should be used in a 2.25 ft^3 enclosure.

Nice, buddy what are the dimensions of that box for the 12w7.... 18" cubed ? - driver and bracing? What is the space the driver takes up?

Do you also know what size box for the 13w7?

 

[jnmfox]

That is correct. With the room gain it plays quite deep and quite loudly to boot

I should mention that my room is 15' x 17' x 8' and open to my kitchen & dining room (both of similar size) as well as my upper level stairway.

Sounds a lot like my room. How many cubic feet of open space do you have?

The 2ft^3 PE enclosures will work fine with the 12W7 though they are not up to my standards.

The 3ft^3 PE enclosure would work with the 13W7 as well.

The PE enclosures are made pretty well, but it would definitely not hurt to reinforce them some.

I'd love to build my own enclosures but like I said before I don't have the tools, skills, or time to build them.

 

[annunaki]

Nice, buddy what are the dimensions of that box for the 12w7.... 18" cubed ? - driver and bracing? What is the space the driver takes up?

Do you also know what size box for the 13w7?

I will have to get them for you. I want to say something like 16" x 25" x 14" as a guess. I believe driver displacement is like .15ft^3 for the 12W7. The bracing is about the same or so maybe less.

As for the 13W7 I will have to check that out a bit later tonight.

 

[annunaki]

Sounds a lot like my room. How many cubic feet of open space do you have?

I would say, approximately, in the 4,500 ft^3 to 5,000 ft^3 range.

I'd love to build my own enclosures but like I said before I don't have the tools, skills, or time to build them.

The PE enclosures will work. I used the 3.0 ft^3 one for my parents with the Dayton Titanic Mk III. It works quite well and they are built pretty well for a pre-fab. In your case, I would not have any worries with using that enclosure. However, I bet if you spoke with a local cabinet maker they could possibly do an enclosure, of higher quality, for you for the same price. MDF is pretty cheap.

If you have dimensions (of the maximum allowable size for H x W x D), I can probably get you a cut list for the cabinet maker with some basic drawings of how to construct it.

 

[jnmfox]

If you have dimensions (of the maximum allowable size for H x W x D), I can probably get you a cut list for the cabinet maker with some basic drawings of how to construct it.

Thanks, I'll take you up on the offer if I go this route. I wouldn't want you spending time on something I'm not 100% sure I'm going to do.

 

[Warpdrv]

Personally I just assume do a square box, its so easy to do.....
Make it a bit bigger and use extra bracing....

 

[annunaki]

Personally I just assume do a square box, its so easy to do.....
Make it a bit bigger and use extra bracing....

My enclosure was originally for the vehicle and has since been implemented in my home.

I am not a fan of total cube sub systems. Rectangles can fit into different areas that a cube sometimes won't.

 

[Warpdrv]

My enclosure was originally for the vehicle and has since been implemented in my home.

I am not a fan of total cube sub systems. Rectangles can fit into different areas that a cube sometimes won't.

Thats true, doesn't really matter either way... as long as it goes boom

 

[annunaki]

Thats true, doesn't really matter either way... as long as it goes boom

So true, accurate articulate boom of course.

 

[annunaki]

I check out the 13W7 and with a 3.0 ft^3 enclosure the overall Qtc is at .759 which is totally acceptable. This allows an anechoic f3 of 34hz which is very good. Adding another cubic foot gets the f3 to 33.6hz and the Qtc to .709. very minimal if any audible gain by adding the extra cubic foot.

The 12W7 can go as small as 1.75 cu.ft before it begins to cause a minimal amount of rise in frequency response. Even at 1.75 ft^3 it still has a Qtc of .78 which is quite acceptable.

 

[jnmfox]

Thanks for all the responses.

I am still curious about the DCX over the DSP or FBQ?

I have considered getting the DSP1124 or the FBQ2496 to use with my current sub. Why is the DCX recommended when going the DIY route?

 

[Warpdrv]

If you haven't found an answer to this question, you will find tons of relevent info and differences on all these products over at HTShack...
http://www.hometheatershack.com/forums/

Look for the BFD section...

 

[WmAx]

Thanks for all the responses.

I am still curious about the DCX over the DSP or FBQ?

I have considered getting the DSP1124 or the FBQ2496 to use with my current sub. Why is the DCX recommended when going the DIY route?

The DCX is not just a paramteric equalizer. The DCX is the ideal high pass and low pass crossover to integrate your main speakers with the subwoofer(s). A simple HT receiver(even flagship models) have primitive/simple crossover sections that are not capable of providing ideal crossover functions in most cases(the exceptions are when by mere chance their limited functions are adequate). In addition, the powerful multiple filter options in the DCX allow you to adjust the bass signature to your preference. You can easily make a ported cabinet sound like a critically dampened sealed one if you so desire, yet keep the massive SPL potential and lower distortion advantages of the ported system. It also allows you to adjust the main channel signature(s) to your preference, assuming they are low enough in coloration to begin with to allow successful adjustments.

-Chris

 

[jnmfox]

The DCX is not just a paramteric equalizer. The DCX is the ideal high pass and low pass crossover to integrate your main speakers with the subwoofer(s). A simple HT receiver(even flagship models) have primitive/simple crossover sections that are not capable of providing ideal crossover functions in most cases(the exceptions are when by mere chance their limited functions are adequate). In addition, the powerful multiple filter options in the DCX allow you to adjust the bass signature to your preference. You can easily make a ported cabinet sound like a critically dampened sealed one if you so desire, yet keep the massive SPL potential and lower distortion advantages of the ported system. It also allows you to adjust the main channel signature(s) to your preference, assuming they are low enough in coloration to begin with to allow successful adjustments.

-Chris

From reading your other posts about the DCX you have to use an external amp to be able to use the DCX with your mains. I am using my AVR, and probably will be for the foreseeable future. Would you still recommend the DCX over the others? Where is the best place to pick-up a DCX?