[Danothemano]

Well, I think I've decided on a sonosub. This is what I've modeled in the program.


That is with 2 4" ID ports (PVC) 2ft. long. Now all I have to figure out is what driver and amp to use. I'm pretty sure I want a 15" driver, but have no idea where to start. I was going to buy the Tempest, but it is out of stock. I'm trying to keep the driver + amp under $400. Anyone have any suggestions? Room size is 12x13.

 

[Mike P.]

The Tempest would only work in that setup with an input power of 100 watts. Above that the port air speed would be a problem. The best way to do this is pick a sub and then model it so you get the most performance from it.

Under 400 for a sub and amp will limit your choices. If you want a 15 inch sub, a good value would be the IXL-15 from Mach 5 audio, $220 shipped. There are cheaper subs from Parts Express. It will depend on what you want for performance.

 

[salvasol]

I'm not an expert ...Mike helped me to model my sonosub (I'm starting to buy the parts).

It will be a 18"x61" sonotube using a Mach5 IXL 15.2.2 (bought it yesterday) ...I already have the amp (BKA 1000), maybe you can get the same driver and look for a used amp ($180) or increase your budget a little to get a new amp ...I think the Behringer 1500 is around $290 :yes:

Good Luck

 

[Danothemano]

So if I could raise my budget $50 or so, what could I do then? Keep in mind my room is only 12x13.

 

[salvasol]

So if I could raise my budget $50 or so, what could I do then? Keep in mind my room is only 12x13.

We have the same cu ft (my Ht is 9x18x8) ...if you're okay getting a use amp, there's some right now on ebay. I bought a refurbished Samson Servo 600 a couple of weeks ago for $260.

You can start with a small amp (300-400watts) and later upgrade to a bigger one if you need it. :yes:

 

[Mike P.]

IXL-15.2.2 from Mach 5 audio, $220 shipped,

http://www.mach5audio.com/zen/index.php?main_page=product_info&cPath=65&products_id=180

and a O-Audio 500 watt amp $229 + $14 shipping = $243

http://www.oaudio.com/500W_SUBAMP.html

Total - $463. A combination you won't regret!

 

[Danothemano]

I'm confused on what you said Mike. What does you mean by modeling it? I'm assuming you're talking about the program WinISD, but I don't understand the modeling part. How can there be too much air speed?

Also, I'd kinda like to keep the amp on the outside, so I don't have to build a box for it. Or is it just cheaper to get a plate amp?

 

[thxgoon]

The IXL15 will work in that enclosure but 18hz looks like a better tuning point. Gives you 2 db additional output but there's not much loss in extension. An 8" port 39" long should do nicely

 

[Danothemano]

So for the port I'd use 8" sonotube right? I just caulk it in there?

 

[thxgoon]

Yep. You can use whatever adhesive you choose, I used liquid nails.

 

[Mike P.]

I'm confused on what you said Mike. What does you mean by modeling it? I'm assuming you're talking about the program WinISD, but I don't understand the modeling part.

When using a program like WinISD, you find the right size cabinet, tuning point and vent size to suit the particular sub. That's called modeling.

How can there be too much air speed?

A port resonates the most at the tuning frequency, less above and below. When a port resonates, the air moves back and forth through the tube. If a port tube is too small in diameter, the air moves too fast to the point where it starts making noise. This is called port "chuffing". A larger diameter port keeps the air speed down to prevent chuffing.

Also, I'd kinda like to keep the amp on the outside, so I don't have to build a box for it. Or is it just cheaper to get a plate amp

I'm not sure what you mean here.

 

[Danothemano]

I'm not sure what you mean here.

I guess I did word that a little weird. What I was asking was whether it's better to go with an external amp (Like a Behringer 1500), or just buy a plate amp that I would have to attach to the tube somehow.

So I guess my question is, what amp should I buy now since I think I've chosen the Mach 15" driver?

 

[Mike P.]

The O-Audio plate amp has a few features not usually found on amps llike the EP1500. It has a selectable subsonic filter and an EQ function so you can tailor it to your needs. The plate amp doesn't have to be mounted to the tube. I have plate amps that I built square boxes just big enough to mount each of the amps in and they sit on the floor behind my subs. Something like this:

http://www.patcave.com/ampbox/025-6240.jpg

It's a simple solution that works well. If you do want to mount the amp to the tube, that's fairly easy as well.

http://dustin.bunnyhug.net/construction.php#Plate Amp Mount

 

[Danothemano]

The O-Audio plate amp has a few features not usually found on amps llike the EP1500. It has a selectable subsonic filter and an EQ function so you can tailor it to your needs. The plate amp doesn't have to be mounted to the tube. I have plate amps that I built square boxes just big enough to mount each of the amps in and they sit on the floor behind my subs. Something like this:

http://www.patcave.com/ampbox/025-6240.jpg

Ah, that is a good idea. So you just run the wires from the box to a terminal on the tube. I guess that could work well. Also, on the 8" port made out of sonotube also, do I need to flare it somehow? Inside and outside?

 

[salvasol]

Ah
.. do I need to flare it somehow? Inside and outside?

That's a good question ...I also want to see the answer if there's any difference on performance ..:yes:

I think is optional, I'm not planning on using them ...but I would like to know, and if it helps I added to mine.:bigsmile:

 

[Danothemano]

Is 500 watts going to be too much for such a small room? I mean, I am trying to keep this project semi-budget.

Also, do I need to make the endcaps more than 3/4" thick? I see most people gluing two together, but I don't really see how that helps anything.

 

[Mike P.]

on the 8" port made out of sonotube also, do I need to flare it somehow?

If all you're ever going to power the sub with is the O-Audio 500 watt amp, then flaring isn't necessary. The port air speed will be low enough. Keep in mind that this sub in this setup can handle 900 watts. Should you move to another location and have a large room you could upgrade the amp for more output. With 900 watts flaring would be a good idea. If you flare it now, you'll have no issues in the future. Something to think about.

Is 500 watts going to be too much for such a small room? I mean, I am trying to keep this project semi-budget.

I don't think so. Nothing saying you have to use all the power. Better to have an amp with power to spare then one that is maxed out. This setup models to about 112 - 113 db with 500 watts, plus room gain. Consider it an awesome HT experience!

Also, do I need to make the end caps more than 3/4" thick? I see most people gluing two together, but I don't really see how that helps anything.

It makes the baffle stronger for one thing, not that a double thickness is required. There are plenty of subs built with 3/4 inch material. It's more for the look of the finished product. Having the outside end cap an inch or two larger in diameter then the sonotube allows for a professional looking sub compared to a sonotube with an end cap flush mounted inside the tube. Just my opinion.

 

[Hunter844]

It makes the baffle stronger for one thing, not that a double thickness is required. There are plenty of subs built with 3/4 inch material. It's more for the look of the finished product. Having the outside end cap an inch or two larger in diameter then the sonotube allows for a professional looking sub compared to a sonotube with an end cap flush mounted inside the tube. Just my opinion.

Yeah I kinda got carried away cutting circles the other day for my project and forgot about that little tid bit but I think I've got a plan as an acceptable work around. It may not be as professional looking as I would like but I think it's still going to look good.

If I had it to do over again I would not have got this EP1500 because of the subsonic deal, that was just something I didn't take into account at the time but I'll make the most of it. I'm still not totally sure what the acceptable method for wiring it to my Tempest X will be. Bridged-mono appears to have too much juice for the driver but in reality I would never listen to it loud enough for it to matter I wouldn't think.

 

[Danothemano]

Yeah I kinda got carried away cutting circles the other day for my project and forgot about that little tid bit but I think I've got a plan as an acceptable work around. It may not be as professional looking as I would like but I think it's still going to look good.

If I had it to do over again I would not have got this EP1500 because of the subsonic deal, that was just something I didn't take into account at the time but I'll make the most of it. I'm still not totally sure what the acceptable method for wiring it to my Tempest X will be. Bridged-mono appears to have too much juice for the driver but in reality I would never listen to it loud enough for it to matter I wouldn't think.

So if you could do it again, would you get the O-audio amp? Or is there something else I should be looking at?

 

[SteveCallas]

Flaring ports definitely improves performance - it delays the onset of audible chuffing. Always flare when possible.

I would highly suggest NOT settling for a 500 watt amp, it definitely will not be too much for a small room. Power demands increase exponentially as output levels increase, and movies have lots of dynamic, demanding bass peaks. Power demands will likely be over 500 watts for those bursts, you don't want to be caught with your pants down and get amp clipping.

I would also highly suggest not using a single layer of 3/4" material for an endcap, not with a relatively high excursion 15" driver. Not only do the endcaps have to provide rigidity to the sonotube, the baffle has to dampen the energy of the driver. I would go for 3 layers on the baffle (bottom cap), and then you can skimp a little on the top cap if you must. The more layers though, the better.