[Zemanski]

This is my first attempt at building a HT sub. I was really interested in the ed A7S-450. I like sealed subs much better than ported. I have a lot of experience building subs for car audio. I actually won the USAC championship for the 151-300 watt class with two MTX 10" woofers (138 db)several years ago. Enough about that. I was thinking of building two sealed cubes for the ed 18" woofers. If I'm correct, I can essentially build two subs similar to the A7S-450 for the price of one prebuilt from ed. Heres my plan.


2 x ed 18" drivers = $400

1 x EP2500 = $250

1 x DSP1124p = $100

Building Materials = $150

TOTAL - $900


ed A7S-450 w/1300 watt amp and eq.2 = $935


This seems like the way to get the most bang for my buck. My plan is two build two identical 2' cubes and power them with the EP2500 running at 2 ohms stereo and eq'd with the BFD.


I am pretty set on sealed for several reasons. Easier design, smaller enclosure, and I like the sound better. I could build these cubes very quickly and have these up and running in no time.


Any suggestions or advice would be greatly appreciated.

 

[steve nn]

What does their eq.2 amount to? The mono BASSIS works very nice for sealed, but definitely not the only option out there. It is nice though. http://www.marchandelec.com/wm8.html

 

[mrogowski]

First attempt? Ha! It will probably be your last.

You can't go wrong with what you listed. If, after you build your sealed units, you find they aren't up to par, toss 'em and go with EBS.


Best,

Mark

 

[armystud0911]

Theres some drivers that just seem to model very well, my favorite of all time is the MJ18, another one though is the ED190v.2. However, one thing I'd look into (seeing how and more people are doing these large sealed enclosures with them) is adding a bit of mass to the cone. Check out what adding 50g of mass to the cone does in your models, its pretty neat, it takes off about 3dB of output up high where there is too much, and it adds a tiny bit down low. I know adding mass to cones can harm them, but this cone is already 300g, and its not common to find 18's with cones over twice that heavy, its at least something to consider.

 

[Spezzy]



Quote:
Originally Posted by armystud0911 /forum/post/12924136


Theres some drivers that just seem to model very well, my favorite of all time is the MJ18, another one though is the ED190v.2. However, one thing I'd look into (seeing how and more people are doing these large sealed enclosures with them) is adding a bit of mass to the cone. Check out what adding 50g of mass to the cone does in your models, its pretty neat, it takes off about 3dB of output up high where there is too much, and it adds a tiny bit down low. I know adding mass to cones can harm them, but this cone is already 300g, and its not common to find 18's with cones over twice that heavy, its at least something to consider.

How would you go about adding mass to the cone? I have a RL-P18, is it safe? What is the general limit of adding more mass to a woofer?

 

[Danke]



Quote:
Originally Posted by Zemanski /forum/post/12917352


2 x ed 18" drivers = $400

1 x EP2500 = $250

1 x DSP1124p = $100

Building Materials = $150

TOTAL - $900

That's essentially what I have, but I haven't purchased any EQ device yet.


I have gone through two EP2500s and must have been jinxed as I know they are popular here for DIY. I was able to pick up a used QSC RMX 2450 for $300 and am happy with it.

 

[armystud0911]



Quote:
Originally Posted by Spezzy /forum/post/12924210


How would you go about adding mass to the cone? I have a RL-P18, is it safe? What is the general limit of adding more mass to a woofer?

Spezz, the rl-p has a fs of around 20.5Hz, perfect for a HT sub, there is no reason to add mass to your cone. Even if there was, you designed you enclosure around your current setup, adding mass would likely only mess things up. The ED 190v.2 has an fs of 26Hz, this is fine for 12" or maybe even 15" drivers where you don't necessarily want a super deep tuning, but when you do, it creates a problem. First of all, you wind up with too steep of a slope going upwards requiring greater EQ to even things out. Secondly, if you make the enclosure large enough, you wind up with port resurgence. Basically all adding mass does is decrease sensitivity in the upper passband, you loose about 3dB of output around 80Hz and gain about 0.5dB down low, this can help smooth things out in a small sealed box or even large ported, it also will lower the speakers effective vas as well. This is nice whenever you don't want to go nuts with EQ to make things flat.


I use a product called Blue-tack, it is an adhesive that can be molded and remolded freely and is sticky enough to stick to a moving cone. If you carefully measure out how much you use, you can apply this evenly to the speaker's cone to add mass. I don't add more than about 50% of the cones mms, to keep things safe, I wouldn't do more 25%. Keep in mind, I have only done this to test drivers, I haven't done a completed speaker with added mass. I know that its generally not a good idea with woofers and mids, but with subs, I have heard that it can be used successfully. Personally, I would ask Chris from ED about it, he may think your crazy, I don't know.