Great Deal on sub...but now a little help.

[jboogie]

Hey guys, I just wanted to let you in on a deal going on right now. The DIYMA 12" sub spoken of occasionaly is on sale for $100 shipped. I bought two and would like to get some help on modeling them.

Here are the parameters.

Fs: 25.21 Hz
Qms: 4.748
Vas: 41.71 L
Cms: 121.9 um/N
Mms: 326.8 g
Rms: 10.91 mohms
Xmax: 23 mm
Xmec: 32 mm
Dia: 25 cm
Sd: 491 sq. cm.
Vd: 1.129 L
Qes: 0.383
Re: 3.6 ohms
Le: 1.319 mH
Z: 4 ohms
BL: 22.07 N/A / Tm
Pe: 1000w (up to)
Qts: 0.354
no: 0.169
SPL: 84.3 1W/1m
SPL: 87.89 2.8V/1m

It definately likes small boxes as far as I can tell. Now, can anyone get a decent looking HT box figured out for them?

I am having trouble.

Thanks in advance!

 

[lsiberian]

I've modeled it and it appears to be capable of similar response to the Kappas in a smaller box. However getting the air velocity down on the port will be a great challeng. And you will want an EQ to smooth out the response. This will only work in a ported design but it does have great potential.

 

[alexwakelin]

getting the air velocity down on the port will be a great challeng.

Is it a port length issue? I've seen some creative solutions to excessively long ports:

http://www.subwoofer-builder.com/vent-options.htm

 

[lsiberian]

Is it a port length issue? I've seen some creative solutions to excessively long ports:

http://www.subwoofer-builder.com/vent-options.htm

I always incorporate a folded port in every model I do. Even then the velocity seems to be a bit high. However the driver has a very high SPL. Even higher than the Kappa if I remember correctly.

 

[jboogie]

I've modeled it and it appears to be capable of similar response to the Kappas in a smaller box. However getting the air velocity down on the port will be a great challeng. And you will want an EQ to smooth out the response. This will only work in a ported design but it does have great potential.

I noticed the same problem. I am not sure which is the lesser of two evils: 1st port ressonance or M/ps in the port?

Could someone attach the WinISD file they created for this driver so that I could compare mine to their to see if there are any problems with my model?

Finally, with respect to the Kappa, I didn't quite see it that way. Can you explain? I wasn't able to get any good response down to the 20Hz region w/o EQ. Were you?

Thanks again.

 

[fast1]

what are the possible problems with these two?1st port ressonance or M/ps in the port?

 

[alexwakelin]

Finally, with respect to the Kappa, I didn't quite see it that way. Can you explain? I wasn't able to get any good response down to the 20Hz region w/o EQ. Were you?

In the proper box, the Kappa is flat to 20hz.

 

[lsiberian]

I noticed the same problem. I am not sure which is the lesser of two evils: 1st port ressonance or M/ps in the port?

Could someone attach the WinISD file they created for this driver so that I could compare mine to their to see if there are any problems with my model?

Finally, with respect to the Kappa, I didn't quite see it that way. Can you explain? I wasn't able to get any good response down to the 20Hz region w/o EQ. Were you?

Thanks again.

What Kappa driver did you use?

It sounds to me like there where some setup issues or something.

Actually when you high pass it. It will drop the output some but that goes with any ported design. What type of filter did you use on it?

 

[lsiberian]

I noticed the same problem. I am not sure which is the lesser of two evils: 1st port ressonance or M/ps in the port?

Could someone attach the WinISD file they created for this driver so that I could compare mine to their to see if there are any problems with my model?

Finally, with respect to the Kappa, I didn't quite see it that way. Can you explain? I wasn't able to get any good response down to the 20Hz region w/o EQ. Were you?

Thanks again.

Have you gotten accurate T/S parameters. They are usually different from the manufacturer. Also most drivers suck past 1/2 their excursion according to Wmax.

For drivers I suggest only 3 lines. JL Audio *w7. Infinity Kappa Perfect *, Audio Pulse or TC Sounds. The rest are unpredictable and certainly greater risks. I do suggest you look around for builds on your driver