Second opinion on 10" Subwoofer box?

[JG474]

I'm planning on buying a new subwoofer and making a new enclosure that will be overall better than my current SA-8v2 and have a flatter response. I plan on using the Dayton Audio 10" HO DVC subwoofer for this new project. I thought about using the 12" variant, but the enclosure would've been slightly bigger and the only benefit would be ~0.4dB louder, and it wouldn't run out of Xmax as quickly as the 10". Here's the enclosure I've modeled out:

I'm kind of worried about the port being behind the magnet, but the length of the port being inside vs outside isn't final, but it could only come out of the box about 6" more before touching my car's trunk side. So if anyone would have any input on this, I would like it, but I would really like to stick with a circular port since it means less wood cutting and the box wouldn't have to be bigger to accommodate for a wooden-rectangluar port.

Here's the BassBox 6 Pro modeled graphs:

[Joe X]

Engage a cabin transfer function, if you don't have data for it just use the generic default 12 db/octave +3db@50Hz, anechoic response is ridiculously off inside a car, also place the sub far from the internal end of the port, I would likely consider using an optimized slot port looking at your sketch.

[JG474]

Engage a cabin transfer function, if you don't have data for it just use the generic default 12 db/octave +3db@50Hz, anechoic response is ridiculously off inside a car, also place the sub far from the internal end of the port, I would likely consider using an optimized slot port looking at your sketch.

Hmm. So I should make a model around this if I want a close enough flat response? Is +3dB @ 50Hz the average for gain for cars based on length?

Edit:

So I tried different box sizes and port tunings, but I couldn't get a flat response; I tried a sealed box, much smaller, 12"x13"x12", and I got a good response:

I thought sealed enclosures weren't as loud as ported? Or does that only apply when the sealed box is in an open environment, dropping the cabin gain? If I roll down my windows, will I lose cabin gain, giving me the sealed response without the cabin gain?

[Joe X]

Sealed performs about flat inside a vehicle (yellow plot), one thing response curves can't tell you is what you will like, I would recommend building something and listen in. most of us will prefer ported.

[JG474]

Sealed performs about flat inside a vehicle (yellow plot), one thing response curves can't tell you is what you will like, I would recommend building something and listen in. most of us will prefer ported.

Well compared to what I have now, one SA-8 v2, the sealed should be a lot better:

The orange is the 10" sealed w/o cabin gain, yellow and red 10" sealed w/ cabin gain, and the green is what I currently have, the SA-8v2, w/ cabin gain. I currently don't like the peak at 40Hz since it's already overpowering, so a sealed almost-flat response would be great, if it performs like it does in the model.

Edit: I've modeled out the sealed boxes:

[Joe X]

Nope, the yellow curve has cabin gain on it look it up, in anechoic response sealed will typically start to roll off at about 50-60hz 12dB/octave, the other thing is that you have selected the normalized amplitude response so the output advantage of ported can't be realized, click the tab below to compare SPL. That peak you see is partially due to the net vol and tuning you have chosen.

[JG474]

Nope, the yellow curve has cabin gain on it look it up, in anechoic response sealed will typically start to roll off at about 50-60hz 12dB/octave, the other thing is that you have selected the normalized amplitude response so the output advantage of ported can't be realized, click the tab below to compare SPL. That peak you see is partially due to the net vol and tuning you have chosen.

I said the yellow and red did have cabin gain. Here's the output compared:

The ported SA-8v2 is only slightly louder at 40Hz compared to the sealed enclosures. The SA-8v2, when using only one, has an okay-ish flat response if you power the voice coils separately, powering it any other way gives peaks and spikes in its response regardless of box size and tuning.

[ChevyBoy95]

when are people going to learn a plot isnt everything......

[Joe X]

Had the sa8v2 entered earlier and ran it:

Blue and red - compensated

green and yellow - anechoic

Sealed spec: Vb = 0.28 cubes net, ported spec: Vb= 0.5 cubes net @ 35Hz

And yes at the recommended net volume range it will peak a lot, so no wonder how this subs manage to get loud being small.

[Joe X]

For SQ flat performance I would look in to a 12" made for sealed SQ sub like the image dynamics IDQ sub.