Vega124 Box size and tuning for HT

[marcus555dc]

Hello all... This is my first time here, I am new to HT subs and a have an old vega124 sitting around. I was hoping to put it to use in a budget HT setup... I appreciate any help.

Using WinISD for the first time this is what i came up with: (does it look ok?) I dont really know what I should be tuning forbut i figured 28hz would be a start in a 2.2 f^3 ported enclosure. I will be using a 240 watt dayton amp.

***Also, what things should i watch for when plotting enclosures, ie. what are important parameters. Sorry I am new to this. I also have a PPI 154 C2 sub that I was thinking of using in a 2 FT^3 sealed enclosure. I know Car subs are not the best choice for HT but i have them and why not put them to use until I can afford properly designed HT subwoofers. both subs will not be used in the same system.

Thanks,

Mark


Driver : Cerwin - Vega 124
Project by : me
Project for : you
--
Number of drivers : 1
Box type : Vented
Box size : 62.3 l
Tuning frequency : 30.00 Hz
Vent : 1 vent(s)
0.355 m length for each
0.102 m round


Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 -14.83 99.97
25.00 -7.48 107.33
30.00 -2.60 112.20
35.00 -0.74 114.07
40.00 -0.45 114.35
45.00 -0.52 114.29
50.00 -0.60 114.20
55.00 -0.64 114.16
60.00 -0.65 114.15
65.00 -0.64 114.16
70.00 -0.61 114.19
75.00 -0.58 114.22
80.00 -0.55 114.25
85.00 -0.52 114.29
90.00 -0.48 114.32
95.00 -0.45 114.35
100.00 -0.42 114.38

 

[richie00boy]

Yes that looks pretty good for your application. Tuning at 30Hz you will need to make use of the high-pass (subsonic) filter found on most plate maps.

Car subs can be really good as well.

You need to check the excursion plot using WinISD Pro.

 

[marcus555dc]

Excursion looks ok down into the low 20's. However I doubt they really move 19mm in a ported box. I figure they will be safe to about 12-14 mm at 22hz. Is that a fair assumption?

 

[richie00boy]

I'm not sure what you mean. If the sim in WinISD shows them moving to 19mm with your tuning and box size then that's what it will do unless you protect the drive unit with a filter.

In my experience 30Hz is at the very top end of tuning for a cinema subwoofer and you will see some massive cone excursions. I would strive to tune a bit lower and use a filter if it was me.

 

[marcus555dc]

Should i be looking more towards 22-25hz. Also would that sound ok with music or should i stay high if i want to keep it musical too? Thanks for help!!!

 

[marcus555dc]

RE xmax comment above. CV claims these subs have a 19 xmax. I think thats in a sealed box. I was saying, I had assumed the excursion limits to be around 12-14 mm in a ported enclosure, which if true, keeps them safe down into the mid20's. Under 23hz they start moving ALOT +19mm

 

[richie00boy]

Yes more down towards the low 20s would give you better protection for HT. IMO the musicality of the sub is not directly dependent on the tuning frequency, rather the performance of the driver and box and vent system as a whole. It also depends what you mean by musical. Generally tuning lower will tend to tighten things up, some may like this, others may prefer a high impact sound.

The Xmax claims by the manufacturer are nothing at all to do with what box it is in, it is simply the limits the driver can move linearly. Do not assume anything about excursion in any enclosure! You must check the simulations.

 

[marcus555dc]

Thanks, sounds good, I'll tune lower!

I did model the xmax; what I was trying to convey was when it got to 22-25 Hz it was between 12-14 mm. That is the reason I modeled the tuning and box in that manner. I did not want the driver to reach the claimed 19mm. Just trying to be safe...

Again, thanks for your time, help, and knowledge! Take care.

-Mark