Hornresp adds significant LF response to all designs when using "multiple speakers"

[sine143]

Hornresp adds significant LF response to all designs when using "multiple speakers"

Hey guys, so I was just wondering, why does hornresp extend lf response of all cabinet designs (even Vented designs etc) when you use the multiple speaker option?

when going from say 1 to 8 cabinets (with a vented for example) I notice obvious drop (in frequency) of the excursion minima, group delay peak, and impedance chart peaks. (see attached pic)

It looks to me that stacking multiple boxes is causeing the vent tuning to drop (about 4 hz in the example), but its ALSO decreasing LF excursion requirements at the same voltage. cn someone please explain this to me

 

[weltersys]

Hey guys, so I was just wondering, why does hornresp extend lf response of all cabinet designs (even Vented designs etc) when you use the multiple speaker option?

cn someone please explain this to me

No, can't explain why it is wrong (by a little bit), but you can see the discussion started at post 1771 with attempts:

http://www.diyaudio.com/forums/subwoofers/119854-hornresp-179.html

Multiple closely coupled loudspeakers do exhibit a drop in Fs, though not enough to account for the difference you have noted, as Fb would not change.

 

[sine143]

thanks for the link art. ever since getting hornresp I've been trudging through that thread.

It likely has something to do with the way i've modeled it I think.

I've used method 2 (alternate method) in soho54s hornresp for dummies

Hornresp for Dum... hmm... Everyone - Home Theater Forum and Systems - HomeTheaterShack.com

Let me try the first method and see if it shows the same results.

EDIT

Nope the "correct" method for modelling vented enclosures yeilds a similar result. i'll stick with the alternate method as this allows me to make complicated vent shapes.

 

[Shadydave]

I am curious as to how you can model multiple cabinets.
The only multiple speaker function I know of puts multiple speakers in the same cabinet.
.
Is there another function that I don't know about?

Dave

 

[sine143]

Calculate>>>Tools>>>Multiple speakers>>> bingo bango.

 

[Shadydave]

So if I put in 2 parallel speakers, it simulates 2 separate boxes?
I get it, multiple drivers in same box is done with Nd.
I had just assumed that the other "Multiple Speakers" was a way to do the same thing.

Thanks,
Dave

 

[sine143]

yessir.

do note however that you will likely get to the point where you want to model a stack of more than 9 speakers. for this you will have to double the voltage and include at least 1 series pair.

 

[weltersys]

do note however that you will likely get to the point where you want to model a stack of more than 9 speakers. for this you will have to double the voltage and include at least 1 series pair.

The FR results are the same in either case.

Obviously in the real world you need to consider speaker impedance, but why bother when you are simulating with a perfect voltage source ?

 

[sine143]

i'm just sayin if say he wants to similulate a stack of 16 horns. with a voltage of 100v per horn he could do 200v eg, have 2 series and 8 parallel.

 

[weltersys]

i'm just sayin if say he wants to similulate a stack of 16 horns. with a voltage of 100v per horn he could do 200v eg, have 2 series and 8 parallel.

Or leave the voltage at 100 and get the same result without doing the extra work.

 

[sine143]

but then he can only sim 9 speakers total.

 

[weltersys]

The more speakers, the bigger the sim errors...

 

[sine143]

i'm just sayin if say he wants to similulate a stack of 16 horns. with a voltage of 100v per horn he could do 200v eg, have 2 series and 8 parallel.