SVS Ultra impedance - Home Theater Forum and Systems - HomeTheaterShack.com

 
Thread Tools
post #1 of 3 Old 07-20-15, 10:53 PM Thread Starter
Elite Shackster
 
Talley's Avatar
 
Join Date: Dec 2010
Location: Houston Tx
Posts: 1,295
SVS Ultra impedance

S&V rated them to be 5 ohms nominal and minimum of 3ohms.

SVS rates them 8ohms.

What is it?

http://www.soundandvision.com/conten...Ka7kTFjjYZQ.97

Master Electrician

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

XPA-7 & Krell Showcase 7 | XMC-1 | SVS Ultra Tower system | HSU VTF-15H MK2 | BenQ W1070 | Jamestown 135"
Talley is offline  
Sponsored Links
Advertisement
 
post #2 of 3 Old 07-21-15, 02:05 PM
Elite Shackster
Quenten
 
Join Date: Jun 2007
Location: Tallahassee, Florida
Posts: 2,454
My System
Re: SVS Ultra impedance

I'm thinking it could be dependant on the amount of voltage being supplied to the speaker by the amp at the time of measurement. So it may vary with how one is measureing. I could be wrong though (probably am as electrical is not my cup of tea). I'm sure someone with more knowledge will chime in shortly. Do their measurement data lend any clues as to how they got their numbers?

Ohm's are a unit of measure for Impedance: Impedance = voltage/current
Quote:
So, how do you tell what the impedance of a speaker is? On most cabinets, it should be printed on a label next to the jack. If the speaker is visible, it may be printed on the speaker label or stamped on the frame or magnet. To measure the true impedance of a speaker or cabinet requires a rather complex procedure involving signal generators, power amplifiers and high frequency AC voltmeters. However, with raw speakers and many cabinets, the ohmmeter function of a digital multimeter can help you identify what the impedance of the speaker should be. Generally, the reading given by an ohmmeter will be about 2/3 to 3/4 of the impedance of the speaker. So, a 4 ohm speaker will typically measure about 2.5 - 3 ohms, and an 8 ohm speaker will typically read about 5-6 ohms, while a 16 ohm speaker will measure around 12 ohms.
So they are both more-or-less correct!

Last edited by Tonto; 07-21-15 at 02:27 PM.
Tonto is offline  
post #3 of 3 Old 07-25-15, 06:25 AM
Senior Shackster
Glenn
 
Join Date: Jul 2010
Location: Beckley, WV
Posts: 918
My System
Re: SVS Ultra impedance

Speaker manufacturers are supposed to follow rules for measuring and labeling.
The impedance is measured using AC (a multimeter measures resistance using DC) and the readings do fluctuate.
So if the impedance readings fluctuate, what number are you supposed to go by?...
This is two parts...
1)The nominal (or average) reading.
AND
2) The minimum reading.

A manufacturer may rate the speaker using a single number, which is usually the nominal reading (i.e. 8 ohms) but this nominal reading can only be used if the minimum reading never dips below a certain percentage of the nominal reading (off hand I can't remember what this percentage is). As an example, a speaker may be rated as 8 ohm if the nominal reading is 8 ohm AND the readings never dip below 4 ohms. But if the minimum reading does dip below 4 ohms, the speaker is not supposed to be rated as 8 ohm, the rating must be adjusted accordingly (lowered).
Many speaker manufacturers cheat this rating (possibly SVS?). A higher and a more consistent impedance reading is easier for an amp to run. This is why Jon Lane proudly proclaims and labels his Chane speakers as being TRUE 8 ohm rating (or in the case of the A5rx-c, it is TRUE 6 ohm rating).

Last edited by gdstupak; 07-25-15 at 07:28 AM.
gdstupak is offline  
Reply

Bookmarks

Tags
impedance , svs , ultra

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome