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[jeffsg4mac]

Hey guys. Take a look at what I have in mind to do as soon as the weather permits. I want to get my boxes smaller so I have decided to order two more Titanic 12's and build some Isobaric boxes. How do these look to you at first glance?

 

[annunaki]

Hey guys. Take a look at what I have in mind to do as soon as the weather permits. I want to get my boxes smaller so I have decided to order two more Titanic 12's and build some Isobaric boxes. How do these look to you at first glance?

Jeff,

Your pics are not showing up. I can see the IMG tags when I quoted but they won;t show for some reason??

What did you use to model the isobaric configuration?

Isobaric is great for lowering f3 but requires twice the woofer, twice the power.

 

[BoredSysAdmin]

The problem lies with tiff format imo... convert it to png

 

[jeffsg4mac]

Hmm weird, I see them fine with Safari on a mac. I will fix.

OK here they are again.

 

[annunaki]

Hmm weird, I see them fine with Safari on a mac. I will fix.

OK here they are again.

So are you looking at vented enclosures? vented isobaric? or sealed isobaric? From your models it looks like vented.

 

[jeffsg4mac]

So are you looking at vented enclosures? vented isobaric? or sealed isobaric? From your models it looks like vented.

Yes vented. Slotted port.

 

[annunaki]

Yes vented. Slotted port.

OK, where did isobaric loading come from then??

Let me play around with some modeling later and I will see what I can come up with to verify.

What power level are you simulating your modeling with?

 

[jeffsg4mac]

OK, where did isobaric loading come from then??

Let me play around with some modeling later and I will see what I can come up with to verify.

What power level are you simulating your modeling with?

Isobaric is the configuration if I showed the driver box. look on the upper right corner and you will see the input power is 500 watts. Those graphs are for both drivers in the isobaric configuration not just one driver. Is that what you were asking?

 

[jeffsg4mac]

Here is the box I left out. I would also be curious to see what you guys come up with for this driver

 

[jeffsg4mac]

Anyone try modeling the Titanics yet?

 

[annunaki]

Jeff,

I modeled the 12" Titanic(s) in an isobaric configuration vented. I do not get the same type of response curve with that size enclosure.

A 2"H X 12"W X 47.3"L vent will keep vent velocity below 17m/s with 500 watts input power.

Definitely a small enclosure for a vented enclosure tuned that low. It looks like a potential possibility.

 

[jeffsg4mac]

You got an f3 of 22hz is that correct? Wonder why the difference between the two programs? I am using BassBox Pro.

 

[annunaki]

You got an f3 of 22hz is that correct? Wonder why the difference between the two programs? I am using BassBox Pro.

The f3 I have is shown in the screen shot of about 19hz or so. Two different types of software for modeling is probably a reason for a difference. I am using WinIsd alpha Pro.

 

[jeffsg4mac]

The f3 I have is shown in the screen shot of about 19hz or so. Two different types of software for modeling is probably a reason for a difference. I am using WinIsd alpha Pro.

Oh that just about matches the f3 I got then. So you confirmed my results except my graph looks a little flatter then yours so God only knows which one of those are accurate if either. Other than that it looks like a winner to me

 

[annunaki]

Jeff,
I also have an 80hz low pass filter 4th order assumed in my model. That can account some for it looking less flat. Room gain will fill out your slight dip in response. I think you will be fine with this one.

 

[jeffsg4mac]

Now all I need is for it to warm up so I can start the build I am going to put some sort of nice finish on these too. Either black ash vinyl from Parts X-press or some real wood veneer and a coat or two of satin black lacquer. I am also going to down fire these bad boys.

 

[annunaki]

If you downfire them be sure to allow ample space for them to "breathe", especially if the vent is also downfired.

 

[jeffsg4mac]

If you downfire them be sure to allow ample space for them to "breathe", especially if the vent is also downfired.

I figured 2-3 inches should do it?

 

[annunaki]

I figured 2-3 inches should do it?

I would go as large as you can afford typically. For instance your vent is equivalent to about a 5.53" vent. Normally, one would say that the vent diameter when round is the proper amount of space to allow the vent to "breathe".

In this case, I would think that if you could allow at least 3"-4" you would be fine so long as there are no other obstructions. With your vent velocity being kept in check this helps out in that department too.

 

[jeffsg4mac]

Can one of you model a single titanic in passive radiator design to see what it does? I am not real familiar with tuning those and I have never built one. Or even try a dual titanic with passives if possible. Thanks!

My goal is to reduce the box size and keep and f3 of 20hz + or - a hz or two one way or the other. Thats always the goal though isn't' ?

Boxes now are 45x17x15