Thoughts on my design?

[NogginBoink]

I'm a newbie here; trying to design a sub for HT use. My goals are 105dB at 20-80 Hz.

I modeled an ESB sub using a Dayton 15" Titanic driver in WinISD and the initial graphs look very promising.

However, I'm probably making numerous newbie mistakes and would like comments from the more experienced crowd here.

I've posted my model at http://www.nogginboink.com/subwoofer_design1.htm. I'd greatly appreciate any feedback any of you might have on this design.

-Nogginboink

 

[kornmong]

WOW man I would be happy with that everything you said I agree with except the impendece peak because i dont understand that yet, mine peaked at 14 ohms @ 46hz

and yes if read correctly put in the parmetric equealizer it will change output and all of the results,

im guessing you have a bass boost at 35hz

 

[simon5]

It seems to be very nice. I hope you included the parametric equalizer in the excursion graphs.

You can also do a small rolloff because you'll see gain of about 3-4 dB per octave when the frequency is going down.

Also, include Le in your simulation if you can.

 

[NogginBoink]

Thanks for the tip!

I ran another model with the driver's published Le and it bumped the output by about 1dB from 40-120 Hz.

I also updated my graphs on my webpage to show predictions with and without the EQ.

Is anyone able to tell me what that huge impedance spike is going to do to my sub? Are there other graphs that would help analyze this design that I could provide?

-NogginBoink

 

[simon5]

Impedance peak will not cause problems. It will be easier for your amplifier to drive your subwoofer in that range.

Impedance lows with severe phase shifts are worse my friend !

 

[roddyama]

When the woofer operates at or near it fs the cone excursions increase dramatically causing the impedance to increase. In the case of a vented box design, this impedance peak is usually split into two smaller peaks, one above and one below the box f3. Your impedance peak of 47ohm is not unusual.

 

[paulspencer]

I've made a number of attempts on 3 different browsers and can't get your page to load

I modeled an ESB sub using a Dayton 15" Titanic driver

ESB sub ... kind of like ESP for audio? Extra Sensory Bass?