drop HZ on a box?

[West1 11]

I purchased a custom box a few months ago and just asked for SA-15 box specs (pair).

48"x23"X22" tall with a 10" octoport (17" long)

I would like to drop hz to 29-30hz, is there a way to do this?

[shredder2 241]

Where you tuned now?.. adding volume with the same port area/length will work but port velocities should increase if you do that.

[West1 11]

Currently I am at 33hz.

I am considering swapping out the dual sa-15 for a pair odf U-15's and upgrading my amp. Using the same box tho. The SA's get loud but a little peaky for me liking. Assuming the U series would be a great fit as its a hybrid of the sa and X series.

[shredder2 241]

"Fing" editor has a time-frame.

Anyways... I was typing this to add...

And if you lengthen the port somehow... it'll eat-up volume and tuning might not change as much as you think, so I'd either close-up port area a touch (if not near power minimums) or redesign... my .02

[shredder2 241]

Hows that 10" octoport built... 10" across from corner to corner or straight from flat face to face?.. lil' difference in port area between the two btw

[Jeffdachef 4,805]

make a baffle with an 8 inch sonotube and put it over the 10.

[West1 11]

@shredder2 Here is the design and the box when I picked it up.

 

 

 

@Jeffdachef

So to lower hz, the port must be thinner?

I wonder if I can unscrew the port and pop in a new one that's thinner.

 

Edited September 10 by West1

[shredder2 241]

If you go to an 8"... know how much power you got and watch the length... it might be tuned hella-low and or have port compression (possibly) unless you pay attention to that.

[shredder2 241]

Looks ok to me as is man ... I'd expect around 8.5ft3 tuned to 32hz or so if it's straight across 10'... btw that's quick and dirty

I'd just drop em' in and it looks to me like a bigger amp would be fine (still got the FSD 3800?).

[West1 11]

19 minutes ago, shredder2 said:

Looks ok to me as is man ... I'd expect around 8.5ft3 tuned to 32hz or so if it's straight across 10'... btw that's quick and dirty

I'd just drop em' in and it looks to me like a bigger amp would be fine (still got the FSD 3800?).

I have the FSD2600. It hardly gets warm. A local member met me and set the gains with his SMD DD1. He did set it so I had a hair of play so there was minimal risk of blowing subs. Volts stay between 13.8-14.4. Starts up at 14.6-14.8 and after 5-10min it drops and stays in that area depending on songs played.

The song by E-40, "In a bucket" has dropped volts at its lowest of 13.8. I have not seen anything lower than that on my LED stinger meter.

I am just not happy with the overall loudness. I am hoping deeper bass would solve the unhappiness. On the other hand, my rear view mirror would prefer the sa-15's. On warm days the rear view mirror is useless. It still has a good amount of life based on the few times I need to adjust but it just cant handle warm days and max volume.

 

 

Edited September 10 by West1

[shredder2 241]

35 minutes ago, West1 said:

I have the FSD2600. On the other hand, my rear view mirror would prefer the sa-15's. On warm days the rear view mirror is useless. It still has a good amount of life based on the few times I need to adjust but it just cant handle warm days and max volume.

 

 

 

I feel ya... I'm driving a Honda SUV in Phoenix, can't seem to keep the thing up at anywhere near loud. Man... I'd just do the U-15's and a bigger amp for sure if you want a big difference. 

Electrical might need attention then but you'd expect it for the result you'll most likely see... I'd go at least 4K to push those U's good.

[West1 11]

11 minutes ago, shredder2 said:

I feel ya... I'm driving a Honda SUV in Phoenix, can't seem to keep the thing up at anywhere near loud. Man... I'd just do the U-15's and a bigger amp for sure if you want a big difference. 

Electrical might need attention then but you'd expect it for the result you'll most likely see... I'd go at least 4K to push those U's good.

The only thing I might need to upgrade on electrical is adding a 3rd battery. I assume 0ga is good enough.

I forecast about 1600.00 total to upgrade

pair of U-15's

Amp

Battery

[shredder2 241]

3 minutes ago, West1 said:

 I assume 0ga is good enough.

Idk... if I was going to 4K+, I'd do a couple runs of 0ga if it was me. Cant cost too much and probably best.

[West1 11]

Just now, shredder2 said:

Idk... if I was going to 4K+, I'd do a couple runs of 0ga if it was me. Cant cost too much and probably best.

Well, I might as well do that now Lol. I plan to do my first set of door panel as I want to add some 6.5's to my front stage. I like the 6x9 5-way and I'll use those for highs. The 6.5's will be for mids range but nowhere to put them other than a diy fiberglass job. Hopefully I can start working on this within the next couple weeks. I'm not looking for a pro look, just matching color so it blends in

 

Builder did reach out to me and said he can make a new Drop-in port. I think I'll do this.

[winkychevelle 386]

If you extended the port out away from the box you can lower the tuning.

 

If you cut the flange and slid the flsnge down the port it would increase internal volume while lowering tuning frequency.

 

Without doing the math you might could flip the port around to be totally external but I believe that would tune it way low into the 20s but I'm not doing the math 

[dacheatham 55]

I have a pair of U15s and have tried them in a ~8cf box and a 6cf box. They were much louder and impactful in the 6cft box. I had around 3k on each and it was a little much. I would stick to 2k in a larger box, especially if you tune low. 

The U does share some tech with the X but Sundown is pretty explicit when they state it it is not one of the new “low” platform. It is much more like an upgraded SA. That is why they recommend tuning in the mid 30s. 

Why not go with the X 15s? It looks like the box size would work  

 

[wew lad 1,103]

depends on the sub, i tried shrinking my box and it lost on the meter by at least 1-2dbs

[West1 11]

On 9/11/2018 at 6:17 AM, dacheatham said:

I have a pair of U15s and have tried them in a ~8cf box and a 6cf box. They were much louder and impactful in the 6cft box. I had around 3k on each and it was a little much. I would stick to 2k in a larger box, especially if you tune low. 

The U does share some tech with the X but Sundown is pretty explicit when they state it it is not one of the new “low” platform. It is much more like an upgraded SA. That is why they recommend tuning in the mid 30s. 

Why not go with the X 15s? It looks like the box size would work  

 

I had a X10 and was not very happy with the sound. With that said, I later learned the port was made wrong and it's hard to compare a 10" to a 15".

I am a bit scared to buy the x15's since I've never truly heard one and I've read people complain about the upper sound during songs where a song could be extra bassy and low volume when the hard bass is not playing (basically semi distorted). This is why I narrowed it down to the best of both worlds but I do love me some low tunning sound. 

After this build, I'm done with the Sounds Game so I'm taking my time buying the next set of subs.