Ultimax 12" (Sealed) 1.25cuft, tell me the numbers!

Vitus

Member
2020-02-13 6:04 am
As topic,


Ultimax 12" in a 1.25cuft enclosure, sealed, what to expect?


SPA500 with 6dB boost is available.

What's the lowest tone possible?


I have two of these, placed in the opposite corner.




Why 12's in such a small box?


It looks awesome, deep recess, surround flush with the baffle, magnetic front panel, rounded/fillet opening hole, drool!


Cheers!
 
Ultimax 12" in a 1.25cuft enclosure, sealed, what to expect?
Am new student to WinIsd so fwiw, and correct me if needed!

look like f3=34.4Hz with no EQ.
 

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Vitus

Member
2020-02-13 6:04 am
From some calculations it looks to be your -3db is about 35-36hz. If you use a boost you can get that number lower/louder.

-3dB means the same as F3, right?

F10 would then be -10dB, correct?


As for your calculated 35-36hz, I did a minor calculation of 33hz, in either case - this must be pretty good for a sealed enclosure?

Increasing the enclosure volume yielded only an extremely minor increase is in the lowest possible tone.

The Denovo Audio bundle on Parts-Express sells the 12" with a 2.0cuft box, makes for an even worse lower tone than my own 1,25cuft enclosure choice.

I don't see why they would offer the driver with such a big enclosure when it yields pretty much nothing, in fact, makes for an even worse F3.

Am I missing something here?

Thanks for being awesome!
 

Vitus

Member
2020-02-13 6:04 am
Am new student to WinIsd so fwiw, and correct me if needed!

look like f3=34.4Hz with no EQ.

I find WinISD quite buggy, maybe it's my laptop, but sometimes the values and units won't stay, they change and cannot be changed, and vice versa, tried reinstalling several times, I'll have to give it another go someday.

I think however you should of put the 2 voice coils in series and not parallel?

How that affects the outcome you should ask someone else, though.


Otherwise it's a very interesting find, because the Denovo Flat Kit sold with the Ultimax 12" on Parts-Express use a much bigger box, with the below specifications, it's a direct quote:


Sealed Volume 2.8 ft.
Sealed F3 34 Hz



I don't get why you would go that big?
 

Vitus

Member
2020-02-13 6:04 am
Vitus,All

FYI:

b:)

bjorno, jävla hjälte!

Looks like the optimal Vb get's you to 14hz, I don't even dare, my house won't take it, lol.


Changing the enclosure to 2.8cuft as being sold as a bundle makes zero sense to me, same for you?

Thanks/tack!


Vitus didn't say series or parallel.
bjorno is the master here, I need to get back school to to understand all those graphs, thanks.
Vitus what amp you use to drive and how loud?

Yeah, bjorno seems like the real guru here, I'm lucky he's in this thread, I understand like 10% of what he showed me back there, I'll be sure to save that screenshot for future reference.

The 1,25cuft enclosure volume is somewhat limited by me not being able to accomodating a bigger box in my livin room, I'll have two of them even, making the optimal Vb quite hard to meet the WAF.


What amp? Well, that's the funny thing.

I have these old subwoofers with 180W RMS amps, I plan to use them to begin with, using no boost and see how it'll turn out, otherwise for boosting and when an upgrade is inevitable, I've been looking at the SPA500 for simplicity, maybe SPA500DSP, but most likely the SPA500.

Has the 6dB boost as I need to go lower, and I like the simlpe design, inside and out.


I have yet to calculate how loud I can go, but I think somewhere around 108dB.
 
What amp? Well, that's the funny thing.

I have these old subwoofers with 180W RMS amps,
Has the 6dB boost as I need to go lower, and I like the simlpe design, inside and out.

I have yet to calculate how loud I can go, but I think somewhere around 108dB.
I have amp that couldn't take 2 ohms.
I have amp that could take 2 ohms driving all day.
If you boost to get the low end just be careful....just saying !
 

Vitus

Member
2020-02-13 6:04 am
Why do you rave about 2 ohms, just put the voice coils in series and it'll be 4 ohm?

bjorno, do you see any disadvantages in other terms than losing potential driver power, by putting the 12" driver in the 35 litre enclosure?

Distortion, fidelity, dynamics etc?

I don't want to do something that's obviously bad here, I picked the smaller enclosure simply because I cannot accomodate bigger, hoping my smaller pick won't hurt performance to such extent that it's all for nothing.


33hz to me is fully acceptable, we'll see how my 180W amp does, otherwise I could always change.

Anything worth mentioning?
 

Vitus

Member
2020-02-13 6:04 am
What I learn is "detail goes a long way!"
180W RMS is it continuous or peak or.....?
go low how low 20Hz 25Hz or ...?
108 dB what frequency? , what scale?


not much info in your first post... sorry!

Sorry, my bad.

180Wrms, 250Wmax.

Go how low? I'm not sure, as low as it allows me to go with the discussed 1.25cuft enclosure, 33hz?

Will my 180Wrms amplifier not allow me to?


108dB, I just took the sensitivity of the driver and added 3dB until I hit max of my 180W amplifier, 250W does not yield much difference.

If you have a suggestion here, please don't hesitate.

I take it as 180W will drive most things, just not to the full extent of the driver.

This not true, will it be horribly bad?
 

4real

Member
2004-05-27 8:51 pm
Steyl
Exactly, am going to say the same thing, learn Hornresp if Vitus found WinIsd buggy. Am still learning day by day.

You must be kidding, right? If you think WinISD is buggy, then Hornresp will be almost impossible to use :p . I'm not saying to not learn it, just that the conclusion based on that observation is somewhat ludicrous. In any case, love to hate them both and you'll be fine :D .

180W will get you up-to 100dB+ down to 30Hz per unit, and only 94dB at 20Hz (looking at the smaller 1.25cuft box). The woofer can take the full 600W over it's entire range in a closed box, so I'd say, more power is always better.
 
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