DIY Subwoofer Help (Amplifier & Crossover)

[cbraver]

Any recommendations for doing a grill cloth? I'd like it to be super-thin so I can see the white Kappa Perfect driver behind it. I think that'd look really cool.

 

[annunaki]

You think a 12W3 can match the linearity of the Kappa Perfect drivers? Measurement confirms that a sealed Kappa Perfect 12.1 has lower distortion than the servo-controlled Velodyne DD12, and nearly matches the DD15 on all issues.

-Chris

The new W3 I am sure would be as linear or better. The W3v2 is probably similar or just a tad bit worse. The W3v3 comes from quite the pedigree in the W6v2 and W7. The W6v2 was the most linear driver ever tested (motor and suspension) for Car Audio and Electronics Magazine.

 

[cbraver]

The new W3 I am sure would be as linear or better. The W3v2 is probably similar or just a tad bit worse. The W3v3 comes from quite the pedigree in the W6v2 and W7. The W6v2 was the most linear driver ever tested (motor and suspension) for Car Audio and Electronics Magazine.

The JL Audio W3v3 12" 8-ohm I see online for like 170 bucks. If it's that good, that might be the way to go. Plus I could power it with a bridged 202 at 8ohms.

Is the W6 a lot better than the W3?

Using JL Audio stuff is good for me because I can get a lot more speaker for the money at my cost. So, if they are the same or better... JL Audio wins.

Honestly, I get lost with the measurements and such. Everyone seems to take different measurements and disagree.

 

[annunaki]

The JL Audio 12W6v2 is a superior driver to the W3v3 and the Infinity. It was rated as the best sounding woofer ever tested by Car Audio And Electronics Magazine. It was also one of the most linear designs they have ever tested (motor and suspension).

http://www.caraudiomag.com/testreports/0403cae_jlaudio_12w6v2_car_audio_subwoofer/photo_09.html


http://www.caraudiomag.com/testreports/0403cae_jlaudio_12w6v2_car_audio_subwoofer/index.html

The Infinity is no slouch that is for sure. However, I would take a W6v2 over it easily. The W3v3 would be very close to it but I believe it would be a bit better. JL Audio's proprietary DMA (Dynamic Mortor Analysis) modeling and thermal modeling program "Cosmos" are absolutely state of the art. Few companies out there have gone to such lengths to design their subs. Harman International being one of the few (Infinity's parent company). With both the W6v2 and W3v3 benefitting from this design process they will surely impress.

The W6v2 models best in a 1.5 cu.ft. enclosure with a QTC of .707. I am going off of memory there so I do not quite remember the F3 (in that enclosure). I would guess it to be around 39hz or so. It is one of the most accurate if not the most accurate sub(s) I have ever listened to. It has plenty of output and would do quite well in the enclosure volume you have available. They were designed with smallish enclosures in mind.

 

[cbraver]

The JL Audio 12W6v2 is a superior driver to the W3v3 and the Infinity. It was rated as the best sounding woofer ever tested by Car Audio And Electronics Magazine. It was also one of the most linear designs they have ever tested (motor and suspension).

http://www.caraudiomag.com/testreports/0403cae_jlaudio_12w6v2_car_audio_subwoofer/photo_09.html


http://www.caraudiomag.com/testreports/0403cae_jlaudio_12w6v2_car_audio_subwoofer/index.html

The Infinity is no slouch that is for sure. However, I would take a W6v2 over it easily. The W3v3 would be very close to it but I believe it would be a bit better. JL Audio's proprietary DMA (Dynamic Mortor Analysis) modeling and thermal modeling program "Cosmos" are absolutely state of the art. Few companies out there have gone to such lengths to design their subs. Harman International being one of the few (Infinity's parent company). With both the W6v2 and W3v3 benefitting from this design process they will surely impress.

The W6v2 models best in a 1.5 cu.ft. enclosure with a QTC of .707. I am going off of memory there so I do not quite remember the F3 (in that enclosure). I would guess it to be around 39hz or so. It is one of the most accurate if not the most accurate sub(s) I have ever listened to. It has plenty of output and would do quite well in the enclosure volume you have available. They were designed with smallish enclosures in mind.

I called both Crown and JL Audio today. I think I'm going to go with the W3v3. The W6 is tempting, but it's way out of my original budget.

First I called Crown. A support guy, who was extremely knowledgable and helpful, basically recommended the XLS202 bridged for the 8-ohm W3v3, based on my budget and their specs. I asked if the 402 would have any benefit, and he said it would be overkill....

...he was right. I called JL Audio and feeding it anymore than 600W RMS voids the warranty on a W3v3. So, with the Crown XLS202 bridged I'd be that the max:

http://mobile.jlaudio.com/pdfs/RecPowerChart.pdf

The JL rep hinted that I needed to be careful using the 202. I'll have to watch the levels and make sure not to overdrive it.

 

[annunaki]

The XLS202 should be fine for that sub. I think you will be pretty impressed with it. I will try to model it in that volume in the next couple of days to get you more specifics.

 

[cbraver]

Thanks so much.

The enclosure is back home, I'll be returning on Monday Dec. 17 or so.. and then I'll measure the exact interior dimensions of the subwoofer box. I'd say my estimation is fairly close though.

So right now I'm at:
Behringer CX2310
(XLR to...)
Crown XLS202 bridged (600W)
(speaker wire out...)
JL Audio W3v3

I'm not gunna lie.... I'm pretty excited about this project.

 

[WmAx]

First I called Crown. A support guy, who was extremely knowledgable and helpful, basically recommended the XLS202 bridged for the 8-ohm W3v3, based on my budget and their specs. I asked if the 402 would have any benefit, and he said it would be overkill....

...he was right. I called JL Audio and feeding it anymore than 600W RMS voids the warranty on a W3v3. So, with the Crown XLS202 bridged I'd be that the max:

http://mobile.jlaudio.com/pdfs/RecPowerChart.pdf

The JL rep hinted that I needed to be careful using the 202. I'll have to watch the levels and make sure not to overdrive it.

I recommend a QSC RMX850 over the Crown. More robust construction, heavier power supply and more substantial output stages to provide for lower impedances. Cost is slightly higer. Since you are so paranoid about overpowering the subwoofer, the RMS850 only produces 600 watts at 8 ohms bridged. However, it can also be used at 4 ohms bridged(850 watts @ 4 ohms) for future use if you go to a 4 ohm driver.

-Chris

 

[cbraver]

I recommend a QSC RMX850 over the Crown. More robust construction, heavier power supply and more substantial output stages to provide for lower impedances. Cost is slightly higer. Since you are so paranoid about overpowering the subwoofer, the RMS850 only produces 600 watts at 8 ohms bridged. However, it can also be used at 4 ohms bridged(850 watts @ 4 ohms) for future use if you go to a 4 ohm driver.

-Chris

I'm not "so paranoid about overpowering the subwoofer," I'm just going by the manufacturers recommendations.

The QSC looks like a great amp, but it's like 85 bucks more expensive than the Crown after rebate. I don't doubt it's a nicer amp, but it is also more expensive. The Crown XLS stuff is for people on a budget, they make comprimises for that. Remember, my original budget was 300.00, 400 if needed. I've already blown both of those out of the water.

What performance benefits will I get from the QSC at 8-ohms? Is it worth spending the extra 85 bucks for? I have to draw the line somewhere. But, if it's a big upgrade for 85 bucks, I'll go for it.

You both are being very helpful with this project, thanks for that.

 

[annunaki]

With the recommended power at on the sub at 300 watts you will be fine with any amplifier at 600 watts rms. Remember that to reach full rated excursion you only need the 300 watts. There is some dynamic capability above that usually about 15%-20% more before you will hear audible distortion.The QSC amplifer, being stable to 4 ohms, should have more dynamic capability than the Crown.

Having the bigger amplifier power available just insures you will not have amplifier clipping on dynamic peaks. That is always a good thing. Even with moderate volumes you will probably only be using around 10-30 watts rms on a sub. However when you have those 12db-13db dynamic passages (above the moderate volume) you have the unclipped headroom to handle it .

 

[cbraver]

What exactly is dynamic capability? Ability to handle peaks? Would I notice the difference? More output? Less likely to blow the subwoofer at high outputs? Better sound?

With the QSC amp and Behringer crossover I'm at 408.00 ... hopefully I can get that driver cheap. Plus I gotta buy cables and such. For 600 bucks (by the time I get cables, polyfil, sealant, etc.), I hope this thing will rock.

 

[annunaki]

Dynamic capability is the ability to handle peaks and transients in the signal. A good example would be a large crescendo during a clasical performance usually in upwards of 15db-20db over the average output volume in the passage depending upon the recording.

Say your woofer will do about 90db at the listening position with an average input signal of 30 watts. Having an amplifier capable of delivering 12db unclipped over that average would require about 600 unclipped watts! To reach an unclipped 20db peak would require a staggering 4,000 watts of unclipped power. Remeber that very brief bursts of high transient power will not harm a woofer. However, if there are a lot of them, often enough, and it raises the average power level above the thermal power handling of the woofer for enough time, it could fail. (I would not worry about this in your scenario with the amps in question if used correctly).

To gain 3db in output the power input to the speaker must double. It is generally accepted that clipping in amplifiers starts to begin near .1% thd and rises rapidly from there. Power output also rises very rapidly as well. In a subwoofer system audible distortion does not set in until the 6%-10% thd range.

 

[cbraver]

Based on that statement, an EP1500 would make sense..

This is making my head spin.

It sounds like, from what you guys have said... the order of preference is something like the EP1500 and then the QSC. The Behringer is cheaper and makes more power... I was trying to avoid it based on their reputation, but, if you both think an EP1500 is the way to go then I'll go for it. Certainly cheaper than the QSC.

 

[annunaki]

I will be experimenting with my W7 in my home soon. I will be using a Behringer EP2500 as soon as funds allow for it. I would have no issues in purchasing that amplifier or the EP1500.

 

[cbraver]

Even though I'll get the driver cheaper than this, here is my breakdowns:

Option 1:
Behringer EP1500 $300
Behringer CX2310 $90
JL 12" W3v3 $250
+Cables, epoxy, e-glass, polyfill, etc. $50

$690.00

Option 2:
QSC RMX850 $320
Behringer CX2310 $90
JL 12" W3v3 $250
+Cables, epoxy, e-glass, polyfill, etc. $50

$710.00


Option one is cheaper and makes more power for headroom, so, I'll give that shot. If I got a W6, I'd need a 2500 though, right?

 

[annunaki]

Even though I'll get the driver cheaper than this, here is my breakdowns:

Option 1:
Behringer EP1500 $300
Behringer CX2310 $90
JL 12" W3v3 $250
+Cables, epoxy, e-glass, polyfill, etc. $50

$690.00

Option 2:
QSC RMX850 $320
Behringer CX2310 $90
JL 12" W3v3 $250
+Cables, epoxy, e-glass, polyfill, etc. $50

$710.00


Option one is cheaper and makes more power for headroom, so, I'll give that shot. If I got a W6, I'd need a 2500 though, right?

Perhaps but you would still be impressed with an EP1500 I feel.

 

[cbraver]

Well, that's good. I'll get the 1500 and get the driver based on my wallet and prices. I know the W6's are fairly heavy, would I have any problem bracing it in the box?

I might have to get 13" instead of 12" ... now that I see the hole cutout is only 11 1/4" for the 12" .... I'm thinking I have a 12" hole in that box. We'll see next week though. The cost difference wouldn't be that big for the 13" anyways

 

[annunaki]

Well, that's good. I'll get the 1500 and get the driver based on my wallet and prices. I know the W6's are fairly heavy, would I have any problem bracing it in the box?

You shouldn't. They are heavy but not W7 heavy .

 

[annunaki]

I ran the drivers in question on WinIsd. The W6v2 would be most at home in an enclosure that small. The F3 (unstuffed box) would be about 41hz in 1.5 cu. ft.

 

[WmAx]

The Kappa Perfect 12VQ is a far better choice for home application in sealed enclosures, it should be noted. With the low Q (no insert) mode, in a 1.5 ft^3 box, it has a natural response of about -3 at 28-29Hz, and -10 at roughly 21Hz. This does have a slight high Q box alignment, with about a 2-2.5 dB peak centered roughly at 50Hz, but that is no big issue and can easily be reduced to flat with a parametric EQ at a later point. The Kappa Perfect VQ in this application will provide for more practical use for home application. Using EQ, for example, to push up SPL on lower frequencies on a W6 or W3 to match the Kappa VQ would likely result in substantial increase in distortion at a much earlier SPL level at the lower frequencies, as compared to using the Kappa VQ, since the Kappa VQ has a natural response of such ideal nature in sealed enclosures for home use. It should be noted that when pushing up LF using an EQ, far more amplifier power is used/required and the driver works at far higher excursion/incursion rates(thus limiting dynamic range and increasing THD).

-Chris