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post #1 of 51 Old 05-20-2013, 03:06 PM - Thread Starter
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Just pulled the trigger on 2 Ultras. I would really like to put together the optimal vented system with the drivers, enclosures, and the crappy space I'm putting them in. TC Sounds site shows a couple of different vented enclosure sizes spec'd for the Ultras. 6.4 cubes at 20hz and 8 cubes for 15 hz. My current subs fire to the front and vent to the sides. I would like to vent out the front on the new set. Has anyone built a vented Ultra or at least modeled a set?

Playing with winISD a bit - 7.8 cubes at 16hz is about as nice as I can make it look on paper. As far as I can tell, I get the same exact thing plus 3db with 4000w as opposed to 1900.

Here's what I have for LFE:
2 18" LMS Ultra, 2 EP4000, and a Reckhorn B-2 for HPF. The room is 12x22 swiss cheese with doorways, windows, vaulted ceiling. Enclosure has one place to go, under the screen, 7x2x2, 6x2x2 would be best for aesthetics. I am replacing a set that occupied the same space. I am ready to sell the EP4000s and order the fp14000 if that is what I need. I am also wanting to replace the Reckhorn with a more accurate unit with a HPF and EQing. Something from minidsp.com maybe?

Here is a 3D rendering that I created in autoCAD for reference wink.gif
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post #2 of 51 Old 05-20-2013, 04:12 PM
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I kinda like 20 cu. ft. tuned to 18 Hz with 2 x 8" diameter ports and HPF at 20Hz....




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post #3 of 51 Old 05-20-2013, 04:47 PM - Thread Starter
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I could squeeze two 10 cube enclosures in that space. That does seem to give a smoother curve. Why 18z? 16hz with 10 cubes each has around more db below 16hz with only about a loss of 1db above.

I get a giant spike of overexcursion with most of the variations at about 30hz, so 3500 watts is the most I could use with this variation.
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post #4 of 51 Old 05-20-2013, 04:56 PM
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Kind of a waste of an excellent sub if you set a HPF at 20Hz.
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post #5 of 51 Old 05-20-2013, 06:27 PM - Thread Starter
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Where would the ideal tuning be? I would like to be much lower than where I am with my SDX15s, which are tuned for 19hz.
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post #6 of 51 Old 05-20-2013, 10:04 PM
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Quote:
Originally Posted by yelnatsch517 View Post

Kind of a waste of an excellent sub if you set a HPF at 20Hz.

Offer a tuning suggestion and I will tell you what a waste it is. The OP is destroying his subs playing music, not movies. This is a great sub because it has very low distortion in the musical range. Not because of it's Xmax. This can be found in other, cheaper drivers. Again, offer a better solution.

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post #7 of 51 Old 05-20-2013, 10:06 PM
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Originally Posted by d_c View Post

Where would the ideal tuning be? I would like to be much lower than where I am with my SDX15s, which are tuned for 19hz.

These do not do well in large, low tuned boxes which is why you see so many sealed builds where eq is involved.

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post #8 of 51 Old 05-20-2013, 10:25 PM
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Quote:
Originally Posted by d_c View Post

I could squeeze two 10 cube enclosures in that space. That does seem to give a smoother curve. Why 18z? 16hz with 10 cubes each has around more db below 16hz with only about a loss of 1db above.

I get a giant spike of overexcursion with most of the variations at about 30hz, so 3500 watts is the most I could use with this variation.

Weird, I don't get the giant spike in my models. I'm showing you could use all available power. 18hz was where I thought port length and resonance was reasonable. I did not try every combination. Also, 20hz lpf because that's as low as Reckhorn will go if I remember correctly.

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post #9 of 51 Old 05-21-2013, 02:07 AM
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Quote:
Originally Posted by SXRDork View Post

Offer a tuning suggestion and I will tell you what a waste it is. The OP is destroying his subs playing music, not movies. This is a great sub because it has very low distortion in the musical range. Not because of it's Xmax. This can be found in other, cheaper drivers. Again, offer a better solution.

Didn't realize the OP was using these for music, my mistake.
Listening to music at 125dB is pretty crazy, I must admit. Please continue.
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post #10 of 51 Old 05-21-2013, 06:45 AM - Thread Starter
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I have destroyed them both ways. Hours of music that's too loud the first time in which I ruined both thermally, and too much during a movie this last time. An explosion got me.

I will use it for both. I listen to music when I'm home (mostly dnb, dubstep, electronic) and watch movies several days a week, but I want to design it low to be best for HT, which will be great for my musical preference with much LFE content. Everybody is happy!

Finally home from a 48 hour shift and made some measurements. Max dimensions are 88x25x21

I should have mentioned it before, but the B-2 goes to 10hz, but I will most likely replace it.
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post #11 of 51 Old 05-21-2013, 10:00 AM
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You may want 4 or 8 Ultra's. If you are real basshead, like most of us on here. DO IT! DO IT! biggrin.gif
Other than dimples forming in the surrounds, the Ultra's don't give "much" indication that they are at their limits, which could pose a problem for you bassheads wink.gif
But whatever you do, try not to blow them up this time, because it could get expensive this time around, just saying eek.gif
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post #12 of 51 Old 05-21-2013, 10:26 AM
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Well, if you want real low you could do something like 20 cu. ft. tuned to 12 Hz with 2 six inch ports. Port length is getting kinda long at 48" and airspeed gets pretty high at tuning (40 m/s) but excursion is in check at full power. Not sure if you would hear chuffing or not. Two 8" ports would solve it but they would be too long and have a resonance in the pass band with your volume limitations. I would still run a 10 Hz HPF, some would argue you don't need it. Also, with a higher tune (like 18 Hz) it is easier to make it bombproof.

GREEN = 20 cu. ft. and 18 Hz w/ 20 Hz HPF
GREY = 16 cu. ft. and 15 Hz w/ 15 Hz HPF
RED = 20 cu. ft. and 12 Hz w/ 10 Hz HPF






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post #13 of 51 Old 05-21-2013, 01:40 PM
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I'll just throw out the option of using passive radiators. The builds would be a lot easier, the enclosures could be 7-8 cu.ft, and there wouldn't be any port noise. The ep4k amps would also have enough power, so you wouldn't need to buy a clone.

The AE passive radiators are less than half the cost of the TC sounds radiators, but I've never used them so I can't speak to their quality or flexibility.
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post #14 of 51 Old 05-21-2013, 02:43 PM - Thread Starter
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Quote:
Originally Posted by BassThatHz View Post

You may want 4 or 8 Ultra's. If you are real basshead, like most of us on here. DO IT! DO IT! biggrin.gif
Other than dimples forming in the surrounds, the Ultra's don't give "much" indication that they are at their limits, which could pose a problem for you bassheads wink.gif
But whatever you do, try not to blow them up this time, because it could get expensive this time around, just saying eek.gif

I wish! I still can't believe I bought two of them.
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post #15 of 51 Old 05-21-2013, 02:46 PM - Thread Starter
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Quote:
Originally Posted by SXRDork View Post

Well, if you want real low you could do something like 20 cu. ft. tuned to 12 Hz with 2 six inch ports. Port length is getting kinda long at 48" and airspeed gets pretty high at tuning (40 m/s) but excursion is in check at full power. Not sure if you would hear chuffing or not. Two 8" ports would solve it but they would be too long and have a resonance in the pass band with your volume limitations. I would still run a 10 Hz HPF, some would argue you don't need it. Also, with a higher tune (like 18 Hz) it is easier to make it bombproof

I like it. One giant box with ports in the middle?
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post #16 of 51 Old 05-21-2013, 02:50 PM - Thread Starter
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Originally Posted by lukeamdman View Post

I'll just throw out the option of using passive radiators. The builds would be a lot easier, the enclosures could be 7-8 cu.ft, and there wouldn't be any port noise. The ep4k amps would also have enough power, so you wouldn't need to buy a clone.

The AE passive radiators are less than half the cost of the TC sounds radiators, but I've never used them so I can't speak to their quality or flexibility.

I'm interested in using PRs - I don't know anything about them. I'm not against your idea of the clone and sealed either for the "easy button." That was my original plan since people are happy with it, and it seems to be the benchmark. The difficulty of the actual build is the fun part for me since that is the one part of all this that I am good at.
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post #17 of 51 Old 05-21-2013, 04:00 PM
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post #18 of 51 Old 05-21-2013, 04:11 PM
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Looks like you need 2 of the 18" AE PR's per LMS Ultra. They will both work but the 2100 gram one tunes lower. The enclosure volume required for tuning low with these seems to be about the same as a ported design but they would look much more badass and no potential for port noise. The PR versions must have HPF in my opinion and preferably 4th order to keep PR excursions in check. Here is the comparison (4000 W signal):

RED = 20 cu. ft. vented and tuned to 12 Hz
YELLOW = 20 cu. ft. w/ 4 1600g PR's, tuning ~16 Hz
MAGENTA = 20 cu. ft. w/ 4 2100g PR's, tuning ~ 14 Hz




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post #19 of 51 Old 05-22-2013, 07:45 PM - Thread Starter
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SXR - Is that 4k you mention 2k for each sub, or 4k each?

I'm going to stay with the plan for vented unless I can't make it work. Quite a bit of extra cash for the PRs is scaring me away from that for now. I have an email to TC Sounds to see if they have any suggestions for vented other than what is on their site. The volume becomes even smaller as I get a favorible port air speed since the port space gets larger. Getting close though.

How about this:
Downside is the port speed is 35 m/s, but with 3x16x65" port with 3" flares
8 cubes
15hz
1900w
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post #20 of 51 Old 05-23-2013, 02:57 AM
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I am getting port air speeds of over 60m/s with 3" ports! with a driver like this, two 6" ports is a bare minimum, I simulated a 12 cubic foot box tuned to 22Hz with three 6" ports and 1900 watt input,
looks very good to me, with port air speed @26m/s peak @21Hz, I added a HPF at 13Hz although with electronic roll off I don't think you actually need one.





I believe 8 cubic feet is just too small to properly port with driver.
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post #21 of 51 Old 05-23-2013, 07:58 AM
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10cu with 2pr my man. Room gain will take care the rest. HP IS REQUIRED.
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post #22 of 51 Old 05-23-2013, 04:42 PM - Thread Starter
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The PRs make the most sense, but they are soooo expensive for not making any sound. I could add 1 more LMSU for the price. Is that why everyone has four? Because they do all these calculations and then say, "what's another $1000?" Curses!!
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post #23 of 51 Old 05-23-2013, 06:02 PM
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They sound so good you can't help but want more. Just wait, you'll know what I mean soon.
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post #24 of 51 Old 05-24-2013, 01:15 PM
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Quote:
Originally Posted by d_c View Post

The PRs make the most sense, but they are soooo expensive for not making any sound. I could add 1 more LMSU for the price. Is that why everyone has four? Because they do all these calculations and then say, "what's another $1000?" Curses!!

There is no free lunch.
You are just moving the problem to another area of the audio spectrum.
You gain in-band SPL and power efficiency, but lose extension and momentum-damping.

Which is better: a Piano with weak stoppers or one that you have to beat on the keys until your fingers hurt to get enough sound out? tongue.gif Pick your poison really.
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Is that why everyone has four?

Because we are running them sealed and trying to squeeze single digits out of them.
With four of them you will be outputting 100db and -20db below clipping, or better.
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post #25 of 51 Old 05-24-2013, 03:09 PM - Thread Starter
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There are some giant boxes in front of my garage that are light as a feather and some tiny ones that feel like they might be filled with plutonium...

I'm going to retro-fit these in some 6 cu ft boxes and seal them until I can figure this out. I want to hear them and don't want to rush it. I have some saving to do if I'm adding 4 PRs, and will have to find some hoes to pimp if I want to buy two fp14000s and 2 more Ultras.
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post #26 of 51 Old 05-24-2013, 06:19 PM
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post #27 of 51 Old 05-25-2013, 04:46 PM
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Originally Posted by d_c View Post

will have to find some hoes to pimp if I want to buy two fp14000s and 2 more Ultras.

bin pimpin' since bin pimpin' biggrin.gif

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post #28 of 51 Old 05-27-2013, 08:09 PM - Thread Starter
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Good stuff right there!

Can't wait to get home and cut up some MDF
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post #29 of 51 Old 05-28-2013, 07:24 PM - Thread Starter
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Alrighty, I think I have a plan, or close to it. I can't do PRs right now. This leaves me cash to upgrade my mains and rear surrounds. Does this look OK?

Two of these:
10 cubes
1900w
15hz
4.25x16" port 73.2" long
air speed 27
1st port resonance 92.4hz
3" port flare
LPF @ 80hz
HPF @ 13hz
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post #30 of 51 Old 05-30-2013, 10:30 AM
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Quote:
Originally Posted by d_c View Post

Alrighty, I think I have a plan, or close to it. I can't do PRs right now. This leaves me cash to upgrade my mains and rear surrounds. Does this look OK?

Two of these:
10 cubes
1900w
15hz
4.25x16" port 73.2" long
air speed 27
1st port resonance 92.4hz
3" port flare
LPF @ 80hz
HPF @ 13hz

I wish I could provide more input, but I haven't built a vented cab before. I put those variables together and it models well, but I can't speak to the air speed.

Depending on what you listen to the most, you could squeeze a few more DB out of 20hz by raising the tuning to 17hz, but you'd also lose a couple DB at 15hz. With a box that size, anything higher than 17hz starts to look bad, so 15-17hz is the ballpark i'd stay in.
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