Help to find out tuning freq for 2 subs

[Beginer 10+ year member]

your tuning will still stay the same, but your frequency response will change. 3 cubes at 30 hz will have a different responce than 1.5 cubes at 30hz. it depends on the sub. try playing with winisd to see how the different volumes affect the response curve.

Well tryed to play with WinISD.

And if I set 3cu.ft box with 30Hz tuning and ONE sub. So peak is at ~32-33Hz.

And if I set 3cu.ft. box with 30Hz tuning and TWO subs. So peak is at ~44-45Hz.

So if I get peak at higher frequency this don't mean that tuning freq is higher? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Because I played with WinISD and before and noticed that peak is ~3-6Hz higher than tuning freq. If box is tuned to 40Hz so peak is at ~43-46Hz.

 

[Mr Cabinetry 10+ year member]

Well tryed to play with WinISD.And if I set 3cu.ft box with 30Hz tuning and ONE sub. So peak is at ~32-33Hz.

And if I set 3cu.ft. box with 30Hz tuning and TWO subs. So peak is at ~44-45Hz.

So if I get peak at higher frequency this don't mean that tuning freq is higher? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Because I played with WinISD and before and noticed that peak is ~3-6Hz higher than tuning freq. If box is tuned to 40Hz so peak is at ~43-46Hz.

NO, it just means that you dB response increased, but, that will be effected as well by the cabin gain frequency of the vehicle as well,however, since your looking to increase the SPL response, you just might like the end result.

Keep in mind that were talking in generalizations here as to what is going to occur, the true measure will be cut for the second sub, mount it and stick it in the vehicle and then determine the result for yourself.

 

[Beginer 10+ year member]

So tuning freq will be the same. Understood.

With two subs dB response increase and peak will be at ~44Hz(with one sub at ~33Hz) by WinISD curve.

Ok. Let's say I will play 44Hz tone.

And let's say we have two boxes:

1st. 3cu.ft tuned to 30Hz with TWO subs

2nd. 3cu.ft tuned to 40Hz with ONE sub

So if we play 44Hz tone with 1st and 2nd box, we will get more dB's with 2nd box right? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Sorry that I'm asking so much, just trying to understand everything //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Mr Cabinetry 10+ year member]

So tuning freq will be the same. Understood.
With two subs dB response increase and peak will be at ~44Hz(with one sub at ~33Hz) by WinISD curve.

Ok. Let's say I will play 44Hz tone.

And let's say we have two boxes:

1st. 3cu.ft tuned to 30Hz with TWO subs

2nd. 3cu.ft tuned to 40Hz with ONE sub

So if we play 44Hz tone with 1st and 2nd box, we will get more dB's with 2nd box right? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Sorry that I'm asking so much, just trying to understand everything //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Well, Naturally your going to get a given amount of db's increase if you up the port tuning, but only in terms of the peak response in vehicle.

SPL is going to increase as well and at what point it hits with a 44 hz test tone to the cabin gain frequency is where your going to hit at and if your aiming for the highest possible SPL/db gain, your going to need a meter to measure that to determine that if your goal is to compete.

He!!, I know someone that has been trying to break 150 for the pass couple of months and tired different enclosure's at different port tuning freq's using the combo of subs and amps and finally broke 150 yesterday using 2 subs and one amp.

So, it really all boils down to experimenting with the combination of subs/ enclosure design to find what your desired goal. Your not going to hit it first time right out the gate.

 

[Beginer 10+ year member]

Yea I know that I need to experiment, but I think that then you know basics you can reach your goal easier.

He made 150dB with two Type R's?? //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

 

[Mr Cabinetry 10+ year member]

Yea I know that I need to experiment, but I think that then you know basics you can reach your goal easier. He made 150dB with two Type R's?? //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

No, he finally achieved that 150 mark with 2 SS -15's.

Yeah, sounds kinda lame that he only did 150 with 2- 15's, but, it took him sometime to get there and alot of trial and error.

Gettin to 150 ain't as easy as led to believe and every system, vehicle and install presents there own set of circumstances.

Who knows, you might break 150 with two 12's with alot of work and effort and alot of patience.

 

[Immacomputer 10+ year member]

So tuning freq will be the same. Understood.
With two subs dB response increase and peak will be at ~44Hz(with one sub at ~33Hz) by WinISD curve.

Ok. Let's say I will play 44Hz tone.

And let's say we have two boxes:

1st. 3cu.ft tuned to 30Hz with TWO subs

2nd. 3cu.ft tuned to 40Hz with ONE sub

So if we play 44Hz tone with 1st and 2nd box, we will get more dB's with 2nd box right? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Sorry that I'm asking so much, just trying to understand everything //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Here is a hint: Read what people have already typed.

Your frequency response in a given enclosure will vary per sub. The tuning frequency is not based on the subs in the enclosure but by the nature of the enclosure itself.

Let me give you an example of something I did.

I used the same sub but different enclosures all tuned relatively close to each other.

Enclosure 1: 3 cubes tuned to 29hz

Enclosure 2: 2.2 cubes tuned to 32hz

Enclosure 3: 1.5 cubes tuned to 30hz.

Enclosure 1 frequency response: Peaked around 30-35hz with a loss in 60hz on up.

Enclosure 2 frequency response: Peaked around 33-40hz with loss from 80hz on up.

Enclosure 3 frequency response: Peaked around 37-45hz with a loss from 30-35 and no noticeable upper frequency extension loss.

Even though the enclosures' tunings were similar, the response was very different between each because of the net volume the sub was seeing.