Sealed DIY questions

[jnmfox]

I asked a question on this thread and WmAx, annunaki, and Warpdrv all kindly responded. Seeing as I have a few other questions I’ve started this thread instead of hijacking the other one.

A little background: My HT use is 95% movies and 5% multichannel music. I calibrated my speakers at 75-80db at a volume level of 0 on my Yamaha receiver. I usually have my receiver’s volume set between -10 to -20 when watching movies, basically I’m not looking for high SPL levels. My current sub performs well but I would like to even out my bass response. I haven’t tested my in-room response, I’ve downloaded REW and purchased the necessary cables but haven’t taken the time to do all the testing, but when I run a sweep I can tell I have some peaks and valleys. I considered adding passive room treatments but seeing as the HT is in our family room the wife said no to that idea. Using two subs seems to be the next best thing I can do but adding another large ported sub in the family room isn’t going to fly with the decorating committee either.

When I heard about the Emotiva ERS-212 I was intrigued by the small size, GUI room correction, claimed frequency response, and price. When WmAx posted a response in the above linked thread it got me thinking about DIY.

What size pre-finished box from PE would you recommend? I don’t have the skill, tools, or time to build the box. With a box that small will it be possible to get a flat response down to 20Hz?

Which woofer? The AXIS is very pricey. Where do you recommend finding the JL W7? I’ve seen other threads in the DIY section using the Infinity Kappa. Would this be an option?

How do you feel about using a FBQ2496 or DSP1124 instead of the DCX2496? I power my speakers with my receiver so I will be using that as my crossover.

I should be getting some funds in the next couple of months, I want to explore all my options before making a final decision.

Thanks in advance for your help!

 

[mike c]

small sealed? the JL 13W7 is around 600 bucks the Axis 15 is 700+.

the JL13 would give you a smaller box, but the axis 15 would give you more output.

 

[jnmfox]

small sealed? the JL 13W7 is around 600 bucks the Axis 15 is 700+.

the JL13 would give you a smaller box, but the axis 15 would give you more output.

There are several options AXIS 15 or AXIS 12, and the JL 12W7 or the JL 13W7, and the Kappa. I understand the bigger the woofer the more output it will typically have. A box to fit a 15" woofer may be bigger than what I'm looking for. A 12" or maybe 13" seems about right. But which one?

 

[mike c]

since the axis 12 and jl 13 are about the same price ... i'd choose the 13w7 over the axis 12 and even the 12w7 over the axis 12.

 

[Warpdrv]

If it was already mentioned I must have missed it, but what size is your room?

You say you listen mostly at moderate levels?

Sealed subs are great, but if you have a large room, you mainly make up for the loss in displacement of sealed by going with multiples of the same sub.

 

[Warpdrv]

since the axis 12 and jl 13 are about the same price ... i'd choose the 13w7 over the axis 12 and even the 12w7 over the axis 12.

+1

If music is more your thing, you might want to think about a pair of JL 12W7's, they just have a more natural ability with the upper bass region, and blend with the mains seamlessly IMO... Its worth that extra buck.... After combining my 15" TC and F112, I think I have found the perfect scenario.... I seriously have never heard better bass then this in my life...

I was just looking, and if you have a Live.com account, you can search for JL 12w7 and it will come up in ebay, if you get a buy it now, you can get 25% off. I have bought a number of things that way, including a couple of amps - EP2500 and got some great deals.

Ebay Item number: 130267243427
479.00 - 25% (Live.com deal) is $359.00 shipped... now thats a great price...
I may just have to jump on a couple of those...

 

[Matt34]

I'm going to use two of these in Parts Express 2.0cu/ft enclosures powered by a Behringer EP2500. If I'm not satisfied with two I will get two more.

http://www.rythmikaudio.com/clearance.html

But I think your interested in subs costing a bit more than those.

 

[jnmfox]

If it was already mentioned I must have missed it, but what size is your room?

The HT is in our family room which is open to everything but the bedrooms and basement. I've attached a sketch. I calculated roughly 4,400 square feet.

<table style="width:auto;"><tr><td></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From Drop Box</td></tr></table>

You say you listen mostly at moderate levels?

Yes

Sealed subs are great, but if you have a large room, you mainly make up for the loss in displacement of sealed by going with multiples of the same sub.

This and the reasons I mentioned in my first post is why I'm looking at getting 2 sealed subs.

 

[jnmfox]

I'm going to use two of these in Parts Express 2.0cu/ft enclosures powered by a Behringer EP2500. If I'm not satisfied with two I will get two more.

http://www.rythmikaudio.com/clearance.html

But I think your interested in subs costing a bit more than those.

Not exactly, I'm always looking for the best bang for my buck. I could even see using something like the Rythmik and then later upgrading to the W7.

What would be the performance difference between the Rythmic or an Infinity Kappa and the JL 12W7?

What would the performance difference be between the JL 12W7 and 13W7? More output?

 

[Warpdrv]

Not exactly, I'm always looking for the best bang for my buck. I could even see using something like the Rythmik and then later upgrading to the W7.

What would be the performance difference between the Rythmic or an Infinity Kappa and the JL 12W7?

What would the performance difference be between the JL 12W7 and 13W7? More output?

From what I have read and heard from other members here and other forums, the Rythmik's are fantastic in SQ, but don't match the output of either the Kappa or JL W7's, the Kappa will be as good as the 12w7, the 12w7 & 13w7 will handle more amp power and have more output in sealed mode....

The 12w7 will offer better upper bass handling and output, where the 13w7 will offer a bit better lower end output... both will produce phenomenal output with the proper amplification...

 

[Matt34]

Not exactly, I'm always looking for the best bang for my buck. I could even see using something like the Rythmik and then later upgrading to the W7.

What would be the performance difference between the Rythmic or an Infinity Kappa and the JL 12W7?

What would the performance difference be between the JL 12W7 and 13W7? More output?

I think for the size of your room the Kappa, JL or TC's would offer more needed output than the Rythmic DC12 I'm using. If I remember correctly though, the DC12 were built by TC Sounds before they went belly up.

Edit: Warp beat me to it.

 

[jnmfox]

From what I have read and heard from other members here and other forums, the Rythmik's are fantastic in SQ, but don't match the output of either the Kappa or JL W7's, the Kappa will be as good as the 12w7, the 12w7 & 13w7 will handle more amp power and have more output in sealed mode....

The 12w7 will offer better upper bass handling and output, where the 13w7 will offer a bit better lower end output... both will produce phenomenal output with the proper amplification...

Wow, if the Kappa will give me the SQ of the w7 but less output for about 1/3 of the price that may be a trade-off I'm willing to make. If the Kappas aren't enough I could always save up and get the w7s later.

If I went the cheaper route with the Kappa would you recommend the 1 ft^3 or the 2 ft^3 PE cabinet?

Looking at the power handling of the Kappa using one EP2500 would be all I could really use, correct?

Thoughts on the BQ2496 vs DSP1124 vs DCX2496 when used with 2 sealed Kappas?

Do you think 2 sealed Kappas (not co-located, I was thinking of putting them up front next to my bookshelfs) would be able to outperform my Hsu for movies?

 

[mike c]

the kappas maybe just as linear as the w7, but it has nowhere near the low output capability of the W7 ... the W7 xmax itself is 2x what the kappa can do ...

you really get what you pay for

 

[jnmfox]

the kappas maybe just as linear as the w7, but it has nowhere near the low output capability of the W7 ... the W7 xmax itself is 2x what the kappa can do ...

you really get what you pay for

Any measurement or guesstimates of what the output difference would be?

Would I need a EP2500 for each w7?

 

[mike c]

maybe you can start with a single EP2500 (one channel per driver), if that's not enough you can bridge each amp to each sub.

no measurements that i know of, but the W7 driver i would guestimate to be twice the driver the kappa is.

more xmax = more low end output for your sealed design ... unless you go ported with the kappas, go for the W7's if its within budget.

 

[avaserfi]

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.

 

[mike c]

yes, that's what i said

why are you still awake?

 

[jnmfox]

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.

If you don't mind I'll ask the same questions for the w7 that I did for the Kappa above.

1 cu.ft or 2 cu.ft box? Could I use one EP2500 and still get "sufficient" output? Thoughts on the BQ2496 vs DSP1124 vs DCX2496?

 

[avaserfi]

Red is the Kappa VQ in 2 cubic feet - 250w
Yellow is the 12W7 in 1 cubic foot - 2000w
Blue is the 12W7 in 2 cubic feet - 1000w

Each sub is given max input before excursion becomes an issue.

Now the VQ clearly cannot be equalized while maintaining any real output, but the JL could be considering how much power it can 'take' before having issues. This equalization will allow for a more flat frequency response at the cost of overall output. Do remember, when you put a sub in a room it will have room gain and interaction effects which will need to be dealt with as well.

 

[WmAx]

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