# Efficiency and Wireing ???

Discussion in 'Archived Threads 2001-2004' started by Geoff L, Dec 20, 2001.

1. ### Geoff L Screenwriter

Joined:
Dec 9, 2000
Messages:
1,693
0
Trophy Points:
0
Lacking on hand equipment and just plain not knowing, :bl: can anyone tell me---
When wireing DVC drivers, dose efficiency change at all ~{increase or decrease}~ when doing so.
Series or parrallel ?
Explain if possible...
Thanks
Geoff

2. ### Geoff L Screenwriter

Joined:
Dec 9, 2000
Messages:
1,693
0
Trophy Points:
0
Anyone, have any input on this.

3. ### Wayne A. Pflughaupt Producer

Joined:
Aug 5, 1999
Messages:
6,123
40
Trophy Points:
6,610
Location:
Katy, TX
Real Name:
Wayne
Geoff,

Efficiency doesn’t change. However, wiring them in parallel will draw more power from the amp, which may increase maximum SPL level. But that will be a function of the amp not the efficiency of the speaker.

Happy Holidays,

Wayne A. Pflughaupt

4. ### Geoff L Screenwriter

Joined:
Dec 9, 2000
Messages:
1,693
0
Trophy Points:
0
Hi Wayne,
Yes, know about the ohm drop power draw, but did not know if efficiency changed wireing either way...
Thank you for the info on efficiency.
Oh buy the way Wayne, going to my brothers to start the set up in the new house after Christmas. Kinda looking foward to it now, as opposed to before talking with you.
Will post our outcome on the bottom end thing!
Thanks again,
Geoff

5. ### Greg Monfort Supporting Actor

Joined:
May 30, 2000
Messages:
884
0
Trophy Points:
0
Hmm, I thought I posted this last night. Oh well, info to confirm WP's answers:

The simplified formula for efficiency is:

n0 = (K*Fs^3*Vas)/Qes

SPLeff = 112.02+(10*log10(n0))

where:

n0 = reference efficiency in percent

K = 9.614e-10 (Vas in liters)

K = 9.614e-7 (Vas in cc)

K = 2.723e-8 (Vas in ft^3)

Since none of these values change whether drivers (or DVC coil wiring) are in parallel or series, efficiency doesn't change.

IMO it's better to look at voltage sensitivity (2.83V = 1W/8ohms) rather than efficiency so that we can accurately compare drivers (or DVC coil wiring) of differing resistances.

SPLsens = 112.02+(10*log10(K*Fs^3*Vas*8/(Qes*Znom)))

So drivers (or DVC coil wiring) in parallel are +6dB/2.83V WRT them in series.

GM

6. ### Wayne A. Pflughaupt Producer

Joined:
Aug 5, 1999
Messages:
6,123
40
Trophy Points:
6,610
Location:
Katy, TX
Real Name:
Wayne
Gee, Greg, very impressive! Maybe I should retire… :b

Happy Holidays,

Wayne A. Pflughaupt

7. ### Greg Monfort Supporting Actor

Joined:
May 30, 2000
Messages:
884
0
Trophy Points:
0
Oh no, you don't get off that easy as I don't have time to post all that often.
I've answered this query so many times I keep an email to copy/paste.
GM

Joined:
Dec 9, 2000
Messages:
1,693