Need help in TH modelling

[killa12222]

Bjorno,

Looks really good, except for the rather violent looking phase response and also the massive size needed. I figured that a 12" TH would be way too large for my room (about 13ft*9ft). The Dayton QT210-4 8" modeled extremely well and is about half the size, assuming that my values are correct

An externally hosted image should be here but it was not working when we last tested it.

 

[bjorno]

Bjorno,

Looks really good, except for the rather violent looking phase response and also the massive size needed. I figured that a 12" TH would be way too large for my room (about 13ft*9ft). The Dayton QT210-4 8" modeled extremely well and is about half the size, assuming that my values are correct

An externally hosted image should be here but it was not working when we last tested it.

..Looks really good, except for the rather violent looking phase response..

Agree but IMO you are drawing wrong conclusions of the phase response.

Did you notice that the phase response have all all the excess phase delay removed.

Actually, My design using the SD315-88 driver have smoother in band phase response than your design have also allowing for a wider BW (upper FR bound).See the last plot in the first submitted picture ( Phase response : Delay-16.3 mS).

Your design for a home TH(dayton8inchquatro) show me you need a stereo signal delay unit to remove the excess gldy(Phase) in order to be to properly align your design with your mains or by using an EQ that's able to improve the phase response at ~80 Hz without adding further signal delay .

..I figured that a 12" TH would be way too large for my room (about 13ft*9ft)..

It's up to you to make a decision of what is too large.

..The Dayton QT210-4 8" modeled extremely well and is about half the size, assuming that my values are correct..

Your input data looks good, but your modeling skills show me you are SPL hungry ignoring the fact that your simulated FR is using an signal input level that IMO restricts your TH to only operate (in a one note fashion*) above ~46 Hz where at lower frequencies x-max is exceeded and limiting the TH to sound good.

Also be aware that you need 2 of your TH's to equal the SPL's one Dayton SD315-88 TH I have shown.

* Inserting a sharp HP filter here makes this design to have a BW less than one octave.

I revised your simulation to show what's hidden. See the first picture.

The second picture compares the two designs at I think SPL levels that can be defended.

b

 

[killa12222]

Sorry. I'm a beginner here so I'm still learning and yes, I LOVE bass!

IMO a 12" TH is still way too large for a beginner like me to construct. A 8" would be better. Would my current model work with less power, say 50watts into 4 ohms? Xmax would be just about right then..

Cheers