Some help with an active 3way design

[Ardacer]

So, I'm in posession of 3 speakers, vifa xt25, wavecor wf132tu01 and dayton dcs385-4. I'll be combining these into a 3way solution, I'm trying to get them as flat as possible and chose drivers to have a normal price while being relatively linear and low to mid THD / IMD.

So, I've got some questions, I've modeled my stereo subs in many programs and found unibox to be best allround tool. here are the two options I'm considering:



The closed enclosure would be Linkwitz transformed.
So, what would be better, sound quality and high fidelity-wise, closed or vented? Also, closed could reach "only" 94 db (Methinks it's much more than enough for normal listening).

Here are some more pics, I think the vent sound speed is slow enough, and I could kinda up the wattage to more than 100 watts that unibox says is max input (to about 200-300) , and still stay under xmax (above 20 hz, below is no good, but I'll be using DSP anyway), though I'm not really sure if there are other hidden factors to consider and rather stay safe at 100w...













I can provide the excel sheets if you want to modify / suggest some changes.

Here is the box for the mids, I'd be digitally crossing them at about 200 Hz and keeping (optional vents)sub and mid drivers, and tweeters close to each other for positional sound effects.



Tweeters, I'd be crossing them at 2khz (they are superb in thd and imd above 2khz, linear below, but other distorsions are too big)




Thanks!

[8-Bit Ninja]

@Enderman

[Ahoy Hoy]

Id personally say closed because its got less bass roll off. Also I doubt it be as flat as the graph says nothing is that flat.

[Enderman]

I use winISD. No idea how you got your first graph to be so flat.

There is either way too much smoothing going on or the software isn't very accurate.

[Ardacer]

5 minutes ago, Enderman said:

I use winISD. No idea how you got your first graph to be so flat.

There is either way too much smoothing going on or the software isn't very accurate.

 

I applied the linkwitz transform function on the graph itself. Before it was just a regular 12db/oct drop, like any closed enclosure, this is it without the linkwitz transform :

 

 

Also, unibox appears to be a bit more versatile / accurate? than winisd, give it a shot

[Enderman]

3 minutes ago, Ardacer said:

 

I applied the linkwitz transform function on the graph itself. Before it was just a regular 12db/oct drop, like any closed enclosure, this is it without the linkwitz transform :

 

 

Also, unibox appears to be a bit more versatile / accurate? than winisd, give it a shot

If you haven't yet, yeah try winISD.

It's really old but well trusted, you can use it to confirm your measurements.

[Ardacer]

1 minute ago, Enderman said:

If you haven't yet, yeah try winISD.

It's really old but well trusted, you can use it to confirm your measurements.

thanks, I started with winisd, designed there at first, wanted to confirm with something, this is that something.

[Enderman]

3 minutes ago, Ardacer said:

thanks, I started with winisd, designed there at first, wanted to confirm with something, this is that something.

Ok cool

[Ardacer]

I was just asking generally cause I read all the time that vented subs are inferior to sealed, wanted to ask advice from people who actually built both

[Enderman]

4 minutes ago, Ardacer said:

I was just asking generally cause I read all the time that vented subs are inferior to sealed, wanted to ask advice from people who actually built both

I've heard both. Obviously sealed ones are tighter but if you actually care about sub-30hz frequencies then you NEED it to be ported.

I'll probably never build a sealed sub.

 

What I don't understand is why your first graph of a closed box has less drop off at 20hz than the ported one does.

Sealed boxes drop off about about 30-40Hz unless you are using a 24" driver or something massive like that.

The fact that your sealed box has better low frequency extension than your ported box means something is really wrong... (disregarding SPL)

[Ardacer]

3 minutes ago, Enderman said:

I've heard both. Obviously sealed ones are tighter but if you actually care about sub-30hz frequencies then you NEED it to be ported.

I'll probably never build a sealed sub.

 

What I don't understand is why your first graph of a closed box has less drop off at 20hz than the ported one does.

Sealed boxes drop off about about 30-40Hz unless you are using a 24" driver or something massive like that.

The fact that your sealed box has better low frequency extension than your ported box means something is really wrong... (disregarding SPL)

Actually it doesn't have a better low freq extension, it just cuts the upper part down to the lower, artificially (digitally/electronically) creating a flatter response, while keeping the best properties of the sealed box. It however comes at a price of efficiency, and you NEED to have a driver with very large xmax that can withstand a LOT of power to make up for lost db/W.
The procedure is EQ, called Linkwitz transform.

[Enderman]

2 minutes ago, Ardacer said:

Actually it doesn't have a better low freq extension, it just cuts the upper part down to the lower, artificially (digitally/electronically) creating a flatter response, while keeping the best properties of the sealed box. It however comes at a price of efficiency, and you NEED to have a driver with very large xmax that can withstand a LOT of power to make up for lost db/W.
The procedure is EQ, called Linkwitz transform.

You should be designing the enclosure with no EQ/DPS applied, just pure speaker+enclosure.

The DPS will be applied afterwards to correct all inconsistencies and peaks and stuff, but if you use it while designing the box you can end up with some pretty skewed results which you need to apply even more EQ on top of.

 

For example, your ported enclosure is 4x louder than the sealed one. The frequency response irl will never be flat like in the simulation.

With the ported box, you could use the DSP to lower any peaks and make them flat which would still be louder than the closed box at default.

 

Also, have you tried experimenting with different port diameters and lengths?

And larger enclosures?

Or do you have the enclosure already built?

[Ardacer]

I am aware of these things, I'm only interested in the low extension and general sound quality. Would the linkwitz eq'ed driver be actually as good as the ported one? Would it be better? No point transforming the ported box down there, it's already good as it is. General eq, dips and peaks, I agree, after the box is made. I haven't made the box yet, this is the best I could get with changing the box parameters  

 

Ported box is much louder and better extended while no EQ/transformation is applied, but does it come at the greater expense of sound characteristics? Transforming the sealed box would give me a quieter (94 db is still loud enough?) but actually a flat sealed box down to 20 hz.

Eq and that all comes after, I know it will never be as flat as it is up there. It's impossible. Only electrostatic headphones and hd800 nearfield are somewhat close to that, from my experience.