CSS SDX12 Build Thread

[GO-NAD!]

Both drivers were delivered by UPS yesterday. These are heavy suckers - approx. 45lbs/ea! And, they look almost too good to cover up in boxes. They include installation gaskets and fasteners. I'll warn you now - this build isn't going to go quickly. So, be prepared for an Alex-like pace of completion. Final modelling is not complete. Bob, at CSS, has enlisted people like Jeff Bagby and Nathan Funk to help come up with some numbers. If any of you are interested, the preliminary specs are listed on the CSS website.

These will be in separate ported enclosures, tuned in the 19Hz - 20Hz region.

I'm a bit torn as to how to power them. I like the power/cost aspect of the Behringer NU-000DSP series, but the convenience of going with a pair of SPA1000's is pretty enticing, as well. Decisions, decisions...

 

[lsiberian]

Do you have a woofer tester? If so you can determine the parameters yourself.

The preliminary parameters indicate a 27 liter box(13 3/8" cube) It looks like an excellent sub for small sealed operation

 

[GO-NAD!]

Do you have a woofer tester? If so you can determine the parameters yourself.

The preliminary parameters indicate a 27 liter box(13 3/8" cube) It looks like an excellent sub for small sealed operation

No, I don't have a woofer tester. I have no plans to build more after this, so I don't know that it's worth the investment. Yes, it looks like it would do well in a sealed box. But, I want extension and I'd prefer not to get into EQ-ing it for extension. So, I'd rather go the ported route. If you feel like doing a ported model, I wouldn't object. It seems that when I enter parameters in to WinISD, I get different results than everyone else. So, I don't trust my own modelling.

 

[lsiberian]

No, I don't have a woofer tester. I have no plans to build more after this, so I don't know that it's worth the investment. Yes, it looks like it would do well in a sealed box. But, I want extension and I'd prefer not to get into EQ-ing it for extension. So, I'd rather go the ported route. If you feel like doing a ported model, I wouldn't object. It seems that when I enter parameters in to WinISD, I get different results than everyone else. So, I don't trust my own modelling.

The draw back of porting a sub is you are going to have some level of port compression with nearly any design or you have a very large port.
46.42 with a 22.42 hz tune look optimal. You will need a high pass filter so factor that into your amp purchase.

I recommend the minidsp in a box. You get all the power of a DCX with a very small box at a reasonable cost. You could also get one of the DSP Behringer amps.

Though I strongly recommend getting a Peavey IPR or Yamaha P series for the quieter fans if fan noise bothers you.

 

[GO-NAD!]

The draw back of porting a sub is you are going to have some level of port compression with nearly any design or you have a very large port.
46.42 with a 22.42 hz tune look optimal. You will need a high pass filter so factor that into your amp purchase.

I recommend the minidsp in a box. You get all the power of a DCX with a very small box at a reasonable cost. You could also get one of the DSP Behringer amps.

Though I strongly recommend getting a Peavey IPR or Yamaha P series for the quieter fans if fan noise bothers you.

Yeah, I know this driver needs a longish port. I'm prepared for that. I'm still up in the air on whether to go with a Behringer or just going with SPA1000's. Thanks for the modelling.

 

[lsiberian]

From my calculator

46.42 liters vb
Dimensions
19in x14in x18in

Bracing(This is not significant on the Vb and will certainly vary.
1 x 4 in
33.5 in length

Port
1 x 4 in 38.25 in length
F3 28 hz

Many folks will give up headroom for more extension. I recommend going for headroom instead because most of your material is higher up and you get to play it louder.

You can obviously choose which path to take for yourself. If you want me to calculate a box size and cut out sheet for another vb and tuning let me know my program can do those things too.

 

[GO-NAD!]

From my calculator

46.42 liters vb
Dimensions
19in x14in x18in

Bracing(This is not significant on the Vb and will certainly vary.
1 x 4 in
33.5 in length

Port
1 x 4 in 38.25 in length
F3 28 hz

Many folks will give up headroom for more extension. I recommend going for headroom instead because most of your material is higher up and you get to play it louder.

You can obviously choose which path to take for yourself. If you want me to calculate a box size and cut out sheet for another vb and tuning let me know my program can do those things too.

I can go bigger than that. Even 85 litres isn't too big. I'd certainly prefer a tune in the 19Hz - 20Hz region. Am I correct in thinking that going larger can regain headroom lost to lower tuning?

 

[Swerd]

I've heard some bass cabinet designs done by Jeff Bagby (Salk SS 8, 10, and 12), and I think he has a good sense of how to tune a cabinet for the best bass response without overreaching.

I'd wait to see what ported cabinet design he comes up with.

 

[GO-NAD!]

I've heard some bass cabinet designs done by Jeff Bagby (Salk SS 8, 10, and 12), and I think he has a good sense of how to tune a cabinet for the best bass response without overreaching.

I'd wait to see what ported cabinet design he comes up with.

Oh, I'm not in a rush and I doubt that I'll be cutting any MDF this weekend. I'll wait to see what Jeff comes up with. In the meantime, I'm just curious as to what other guys come up with.

 

[lsiberian]

I can go bigger than that. Even 85 litres isn't too big. I'd certainly prefer a tune in the 19Hz - 20Hz region. Am I correct in thinking that going larger can regain headroom lost to lower tuning?

An EBS alignment is generally best at 1.6 to 1.8 times the optimal flat response. I can model it for you once I have the chance to add an EBS design to my software.

You'd generally tune to around Fs. I can run some models and come up with something later for you.

 

[GO-NAD!]

An EBS alignment is generally best at 1.6 to 1.8 times the optimal flat response. I can model it for you once I have the chance to add an EBS design to my software.

You'd generally tune to around Fs. I can run some models and come up with something later for you.

Sure, if it's not too much trouble. Just be aware, the listed specs might change a bit. I would think that they're pretty close though. Thanks!

 

[GO-NAD!]

OK, using the preliminary specs plugged into WinISD, it looks like there isn't much to be gained by going larger than 85 litres. At that volume, tuned to 20Hz, I have a vent of 1.75" X 12" X 41.25". I'm always uncertain about the vent numbers, because you can manipulate them endlessly and still get acceptable air velocity.

 

[just-some-guy]

good luck with your build. i like my subs, they are pretty nice. but they cannot do loud and low at the same time. when i say loud, i mean pressurize the room loud.

 

[Alex2507]

I appreciate you dragging my name through the mud in post #1 ... really, it's an honor.

Try TLS for an alignment. See if it jives with your other DIY gurus. That looks like an important project. Tell me about the finish. Tell me about how it's going to look. Tell me about how you plan to suffer.

 

[GO-NAD!]

I appreciate you dragging my name through the mud in post #1 ... really, it's an honor.

Try TLS for an alignment. See if it jives with your other DIY gurus. That looks like an important project. Tell me about the finish. Tell me about how it's going to look. Tell me about how you plan to suffer.

This is going to be a form follows function project. Since these subs will reside behind the false wall, finish will consist of a couple of coats of flat black paint. I don't know if I'll even fill the screw holes. I like to make things look nice, but I don't believe in wasted time, effort, and material.

As for dragging your name through the mud, just think of it this way - there's no such thing as bad publicity.

 

[Alex2507]

This is going to be a form follows function project. Since these subs will reside behind the false wall, finish will consist of a couple of coats of flat black paint.

Oh wow, then you can make a box with a 6" PVC pipe 10' long for the port if need be. I did want to see you suffer and I did want to see a pretty sub with at least two or three colors but whatever, it's always about you with you so why should I expect different now?

Seriously, that sure simplifies things. I hope TLS stops by. Tuning the port is sort of important but you can get away with a lot in regards to port noise. With mine I went for low vent velocity simply because I wasn't afraid of size or complexity. I mean I hit 3 walls with the vent in an odd pattern but the short 4" port option with a higher (but not too high) vent velocity was an option presented by TLS. I haven't seen annunaki around for a while either. What's that 85 liter thing in American ft^3? I don't do that kind of math anymore.

This is exciting. I believe you are going to have a fine product on your hands in short order.

If you have a folding vent you might want to dove tail the joints.

 

[GO-NAD!]

Oh wow, then you can make a box with a 6" PVC pipe 10' long for the port if need be. I did want to see you suffer and I did want to see a pretty sub with at least two or three colors but whatever, it's always about you with you so why should I expect different now?

Seriously, that sure simplifies things. I hope TLS stops by. Tuning the port is sort of important but you can get away with a lot in regards to port noise. With mine I went for low vent velocity simply because I wasn't afraid of size or complexity. I mean I hit 3 walls with the vent in an odd pattern but the short 4" port option with a higher (but not too high) vent velocity was an option presented by TLS. I haven't seen annunaki around for a while either. What's that 85 liter thing in American ft^3? I don't do that kind of math anymore.

This is exciting. I believe you are going to have a fine product on your hands in short order.

If you have a folding vent you might want to dove tail the joints.

Yeah, I do have some flexibility with the port arrangement, as I don't have to squeeze it into the smallest box possible. I could even do an external port, so that it looks like the smokestack of a power plant. I just don't know if it's best to keep it internal, so that pressure is equal inside and outside the port. Anyway, looks are very low priority for this project. And yes, that makes me a self-centred ba$-turd, for not prettifying them.

The port will be long - probably in the 40" region. So, bordering three sides is likely. I'm guessing that it'll be similar to a Kappa box.

85 litres is 3ft^3. It would be nice to keep it around that size, but it can be bigger, if necessary. If you have WinISD, you can change units and it will convert automatically.

I certainly hope to have a fine product in the end, but in short order? This is what Bob stated over at HTS:

The specs on the current sheet are based on Nathan's burned in unit. I'm waiting for some better pictures and clarity on the measurement conditions. Meniscus has a slightly different set of measurements but that driver doesn't have the time on it. There will also be some longer term "power to the edge of destruction" tests performed. A longer application notes document is also in process.

So, I'm somewhat at his mercy right now. I could've held off ordering these drivers until the final specs were ironed out, but I....well, I don't have any idea why I didn't wait.

Dovetail the vent joints? You're kidding right? I can do dovetails, but I'd like to have this done before summer. Screws and a $hitload of glue will be just as strong.......ohhhhhh, I'm on to your clever little scheme for me to take forever to finish this project. Take some heat off you, right?

 

[fuzz092888]

If I had $100, I'd say just order the DATS system from Dayton, then I'd buy it from you. It would make everything easier for everyone. Maybe I can work something out if you'd be interested.

 

[GO-NAD!]

If I had $100, I'd say just order the DATS system from Dayton, then I'd buy it from you. It would make everything easier for everyone. Maybe I can work something out if you'd be interested.

I'd have to pay shipping up here, so just out of curiosity, I checked: $37 to get it here. And then, I'd still need someone to model it for me. I think I'm gonna rely on the more learned people for this.

 

[annunaki]

I'll take a crack at this one in a day or so. Been too tied up as of late. In the last two-three months I have had a promotion, relocation, house hunting, a new baby and volleyball tournaments for my (oldest) daughter to boot.