DIY JL 12w7 + EP2500

[adamczap]

Well, here we go again! I am diving into my first DIY sub to complete the home theater in our basement remodel. After some extensive research I scored a great deal ($375) on a 12w7-ae through Amazon, and an EP2500 from guitarcenter.com.

The sub will be hiding in a closet under our stairway with a hole cut through the drywall w/ a mounted grill over it. Is there any reason to build my own sealed box instead of going on Craigslist and buying one that someone used in their vehicle w/ this sub? Please don't kill me for asking...

Another question, specifically to those who have done this (Annunaki!) build: have you had any trouble running the 3ohm 12w7 through your 4ohm EP2500 in bridged mono? Anything I should look out for or specific settings to use?

Finally, what type of patch cables are ya'll running for this? RCA to 1/4", or RCA to XLR? Does it even matter? Also--what size speaker wire? 10ga big enough for this?

Thanks in advance!!

 

[jinjuku]

It this going to be a sealed unit? You may need an active/powered isolation transformer. I know I can't drive my EP2500 off of my Denon with a simple XLR to RCA cable.

 

[adamczap]

It this going to be a sealed unit? You may need an active/powered isolation transformer. I know I can't drive my EP2500 off of my Denon with a simple XLR to RCA cable.

I've never read about anyone using one of these in this setup! Yes, the box will be sealed. JL doesn't need a lot of space, so that's why I thought a pre-made mobile box would suit fine since this is going to be hidden in a closet.

Can you give me some more information/links for your comment above?

 

[jinjuku]

You are going to try running the amp directly off of the receiver first. Your AVR may have enough output to drive the Behringer no problems.

If it doesn't: Applied Research & Technology: ARTcessories™

 

[annunaki]

The EP2500 has no issues running the W7. The actual DCR of the 12W7 runs VERY close to that of a standard 4 ohm speaker so you should not have any issues there.

10 gauge speaker wire is plenty large enough for this sub, but length of the wire is obviously one of the big items to consider. With 10 gauge you can get pretty long before you would have any worries here.

With your cut through into your listening area, will the driver and its output be isolated to firing through the opening only? If not it could possibly cause some odd response issue.

Let me know if you have any other questions on your quest...

 

[adamczap]

length of the wire is obviously one of the big items to consider. With 10 gauge you can get pretty long before you would have any worries here.

With your cut through into your listening area, will the driver and its output be isolated to firing through the opening only? If not it could possibly cause some odd response issue.

I shouldn't need more than 6ft or so of 10ga wire for this project. The driver will be in a closet next to (well, underneath the rack I am building) all the other stuff. I think I am leaning more toward building my own box at this point. I don't see any other way that I will be able to maximize my response unless I do it custom. I'll be sure to take pics when I build it!

Is there anything else that I should know? What about the settings on the EP2500? I saw some people post about the direction of all those little switches. Is there a one-size-fits-all way to do that? If so, please share!

 

[annunaki]

I shouldn't need more than 6ft or so of 10ga wire for this project. The driver will be in a closet next to (well, underneath the rack I am building) all the other stuff. I think I am leaning more toward building my own box at this point. I don't see any other way that I will be able to maximize my response unless I do it custom. I'll be sure to take pics when I build it!

Is there anything else that I should know? What about the settings on the EP2500? I saw some people post about the direction of all those little switches. Is there a one-size-fits-all way to do that? If so, please share!

If you were not going to build your own enclosure what was your plan?

By the way that is one sweet deal you scored on the sub!!!

I do not have all of the dip switch settings handy right now, but there should be some out there for a bridged/ mono setup. The manual also states how to set these for this application.

 

[adamczap]

So what are all the connections needed for this? I think that's the only question I asked that no one responded to. Can I get a cable list?! for the sub to my AVR, I'm thinking 1/4" to RCA sub preout. Good or bad idea?

 

[annunaki]

So what are all the connections needed for this? I think that's the only question I asked that no one responded to. Can I get a cable list?! for the sub to my AVR, I'm thinking 1/4" to RCA sub preout. Good or bad idea?

Use an RCA to XLR cable. I have had much better results this way.

Are you planning to add a mini DSP or DCX 2496?

These will greatly help response in the low 20hz range

 

[adamczap]

Use an RCA to XLR cable. I have had much better results this way.

Are you planning to add a mini DSP or DCX 2496?

These will greatly help response in the low 20hz range

I plan to add the 2496 after a while if I decide what I have isn't good enough . After managing to score that W7 for only $375, I'm tempted to look for another one so I can run this thing in bridged mode!

 

[skyline_123]

After managing to score that W7 for only $375, I'm tempted to look for another one so I can run this thing in bridged mode!

If you find more for $375, please let me know. That's a great deal!

 

[annunaki]

If you find more for $375, please let me know. That's a great deal!

I agree, having an extra in my system would be pretty sweet!!

 

[Haoleb]

You might be happy with the performance of the setup without a DCX and custom enclosure but you will definitely not get near its full potential without both of those aspects. For too many reasons to list. Even the JL "redeye" boxes which are ported, are terrible in my experience and have a ton of port noise. And those are made specifically for these drivers. The thing with regular car stereo subwoofer stuff is that for the most part, sound quality takes a back seat to SPL. One of the biggest downfalls of this is tuning frequency, which is usually 35hz ish... Much higher than most people want in home audio where the low 20's is more desirable. If you look at the spec sealed box for the 12w7 on JL's website the f3 is 40hz..pretty poor for home theater use.

 

[adamczap]

One of the biggest downfalls of this is tuning frequency, which is usually 35hz ish... Much higher than most people want in home audio where the low 20's is more desirable. If you look at the spec sealed box for the 12w7 on JL's website the f3 is 40hz..pretty poor for home theater use.

I totally agree with this. Can someone give me a link to a well-tuned box that would support 2 of these monsters? The box I bought was tuned to 38hz . I'd like to start with the custom box and then see how that changes things.

 

[adamczap]

Ok, new problem: XLR to RCA plugs aren't playing anything? Anyone else experience this?

 

[annunaki]

If you are going sealed with the 12W7, especially without the DCX, a 2.3ft^3 enclosure will net you a Qtc of .70. This is generally received as an ideal sealed alignment.

If going vented prepare to build really large enclosures. About 7ft^3 gross volume. The vent is what becomes the issue, as it displaces so much air (when keeping vent velocity below 17m/s).

 

[lsiberian]

If you are going sealed with the 12W7, especially without the DCX, a 2.3ft^3 enclosure will net you a Qtc of .70. This is generally received as an ideal sealed alignment.

If going vented prepare to build really large enclosures. About 7ft^3 gross volume. The vent is what becomes the issue, as it displaces so much air (when keeping vent velocity below 17m/s).

With that sub your looking at a massive port taking up significant floorspace.

 

[adamczap]

If you are going sealed with the 12W7, especially without the DCX, a 2.3ft^3 enclosure will net you a Qtc of .70. This is generally received as an ideal sealed alignment.

I'm doing dual W7's... Is this recommended measurement for 1 or 2?

 

[lsiberian]

I'm doing dual W7's... Is this recommended measurement for 1 or 2?

59.51(16.87 in cube) liters is for a single sub. You'd double it for a dual sub to 120 liters(21 inch cube)

If you have a height or width you like to aim for let me know.

 

[adamczap]

by the way, can anyone tell me why my XLR to RCA connector (i bought 2, actually) doesn't work? 1/4" to RCA works fine, but hums.