Load Impedance Inquiry

[mengz]

Hi all,

i have 2 woofers and it's a SVC 4 ohm woofer. so i wired them in series, meaning it will have a 8 ohm load on the amplifier right? but it's hooked up to my 2 channel amp in bridged mode.

so what is the current load impedance on my amplifier right now? issit running @ 4 ohm mono or @ 8 ohm mono?

thanks in advance

 

[oldskolboyz]

8 Ohm.. let say your amp pwr output 500wrms x 1 at 4ohm, so at 8ohm become 250rms x 1. If impedance increase, pwr out will decrease by half or double up the impedance & at the same time pwr output will reduce by half.

 

[mengz]

hmm...if thats the case, bcoz the amp is 2x500@4ohm, 1x1000@4ohm. so if running bridge mode @ 8 ohm = 500.

will it be better if i wire 1 woofer to 1 channel so i'll get 500w per channel per woofer, instead of the current 500w for 2 woofers @ 8 ohm?

 

[oldskolboyz]

depend on your sub itself... if U send to much pwr, your sub will koyak.....

right know U just sending 250wrms to each sub.. I think should be no problem coz normaly SVC not hungry pwr sub.. <300wrms laaa..

 

[mengz]

actually.....i think my sub has more than enuff power now....very strong edi. but i just wanna find out if i wanna deliver more power the nxt time i change to better subs, shud i go for stereo so that each sub will get more power than the current configuration.

anyways thanks for the info buddy!

 

[Maxx]

this site might help u.
Basic Car Audio Electronics

 

[cacin]

actually.....i think my sub has more than enuff power now....very strong edi. but i just wanna find out if i wanna deliver more power the nxt time i change to better subs, shud i go for stereo so that each sub will get more power than the current configuration.

anyways thanks for the info buddy!

Bro, if you go through the site provided by Maxx, I think you'll notice that the guy doesn't recommend to connect speaker in series. So, I suggest you connect 1 sub to 1 channel. Then, each sub would get 500W. By the way, your sub is how much RMS? The power rating for the amp is RMS or max?

 

[Kippo]

your amp configuration looks a bit odd. Generally if you bridged a 2/4-channel amplifier, its output will multiply between 3~4 times per channel eg. 2x100w / 1 x 400w or for 4 x 50w / 2 x 150w

in your case, it should be 2 x 500w / 1 x 2000 w

so i seriously doubt you will have 2x500w
generally whether you wire to each channel or all woofer combined to mono channel, both will see the same power.

 

[oldskolboyz]

Using 2 unit SVC 4ohm same as 1 unit DVC 4ohm

a) http://www.crutchfield.com/ISEO-rgbtcspd/learningcenter/car/subwoofers_glossary.html
b) http://www.crutchfield.com/learningcenter/car/subwoofers_dual.html
c) http://www.crutchfield.com/learningcenter/car/subwoofers_wiring.html
d) http://www.crutchfieldadvisor.com/S-0jpgndlxMBW/learningcenter/car/subwoofers/sub_amp_guide.html
e) http://www.crutchfieldadvisor.com/reviews/20030722/subwoofer_power.html
f) http://www.crutchfield.com/learningcenter/car/subwoofers_faq.html


If others ppl said, "Conect sub in series not advisable".. to me that very dumb suggestion I ever heard in my life.

 

[mengz]

but if i'm not mistaken, i read somewhere before that when you bridge mono, the load impedance will drop by half. is this true?

for example, since i have two 4 ohm woofers wired in series, so my load impedance is 8ohm on the amp. but when i bridge it, it will drop by half which means 4ohm. is this correct?

anyways Kippo, the figures i gave are just rough figures for easier understanding....my amp is not giving that kind of power :)

 

[oldskolboyz]

but if i'm not mistaken, i read somewhere before that when you bridge mono, the load impedance will drop by half. is this true?

Nope.. U could be misunderstood.. impedance, damping factor, pwr output & etc control by sub..

for example, since i have two 4 ohm woofers wired in series, so my load impedance is 8ohm on the amp. but when i bridge it, it will drop by half which means 4ohm. is this correct?

Nope.. Power output will drop by half & not Impedance coz as I said earlier Sub control the impedance not amp. Impedance at the amp just a "RATING" to tell us how much it can produce Power Output in watts (rms) at certain impedance..

Normal Class A/B amp only stable at 4Ohm in bridge mode but got some brand can go down at 2Ohm stable (definitely with $$$$ loorr)..

 

[cacin]

Bro oldskol,
This is the info I got from:
Speaker / Amplifier Wiring FAQ - Tutorial

"How do you run speakers in series?
It is not suggested that you run speakers in series. No two speakers will be exactly identical, even if they are the same model from the same manufacturer. This means that they will act slightly different from each other when presented with the same input signal. When wired in series, these differences will cause distortion in the form of back EMF.
You can however run both coils of a DVC speaker in series. The cone movement for both coils will be identical, and will not cause distortion problems.

What is a dual voice coil (DVC) speaker?
A DVC speaker has 2 coils instead of one as in a Single Voice Coil (SVC) speaker. Both coils have the same resistance, and both coils MUST be hooked up to the same channel of the same amp. You cannot run both coils off different channels of the same amp with the same signal, and you must use both coils.
DVC speakers offer a lot of flexibility. Given 2 DVC speakers, there are 4 different wiring methods. These 4 methods are shown below for DVC drivers with 4 ohm coils. "


If I am not mistaken, there is a different of phase for series connected speaker (except DVC). I think it is either 15 degree or 30 degree.

 

[oldskolboyz]

Yes slightly diff but would not more than >10% to each others.. just less than 2%.. I dont think with that small % can create distortion, some more we always play the sub within freq resp recommendation.. let say Freq Repsd around 20hz - 1khz.. the most ppl play around 20hz-60/80hz (SQ) or 20hz-100/120hz (SPL).. If not manufacture would not recommend their SVC in multiple sub set-up either in series or parallel...

How about in parallel, are this 2 unit svc sub connect in parallel become 1 unit ka?

 

[Zenn]

but if i'm not mistaken, i read somewhere before that when you bridge mono, the load impedance will drop by half. is this true?

for example, since i have two 4 ohm woofers wired in series, so my load impedance is 8ohm on the amp. but when i bridge it, it will drop by half which means 4ohm. is this correct?

anyways Kippo, the figures i gave are just rough figures for easier understanding....my amp is not giving that kind of power :)

bridge mono means, combining the 2 channels of an amp into one to run a single driver, like subwoofer.

load impedance depends how u wire the speaker to the amp.
single svc 4 ohm u get 4 ohm load
single dvc 4 ohm wired in parallel u get 2 ohm load
single dvc 4 ohm wired in series u get 8 ohm load

 

[cacin]

How about in parallel, are this 2 unit svc sub connect in parallel become 1 unit ka?

Bro, thanks for sharing your thoughts/knowledge. Unfortunately, I do not have the expertise and/or experience to answer this question :)