Reply
 
LinkBack Thread Tools Display Modes
Old 08-24-2006   #1
 
DIYMA freshman
Join Date: Aug 2006
Location: Singapore
Age: 41
Posts: 43


Rep Power: 100 hyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enough


iTrader: (0)



Default mixing 4 ohm & 8 ohm speakers

what is the effect of using 1 driver in a passive setup with say, 4 ohm impedance, and another with 8 on the same amp channel? would the amp struggle to play some freqs thru the 8 ohm driver, and some thru 4 ohm, and have variable output? variable sound volume?

thanks!
hyun is offline   Reply With Quote
Old 08-24-2006   #2
DIYMA 500 Club
 
MarkZ's Avatar
 
DIYMA Addict
Join Date: Dec 2005
Location: ..........................................
Posts: 6,853

Rep Power: 183 MarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really nice


iTrader: (4)



Default Re: mixing 4 ohm & 8 ohm speakers

The amp won't have a problem. Just don't put both drivers behind the same passive crossover network. Different impedances require different component values.
MarkZ is offline   Reply With Quote
Old 08-25-2006   #3
 
DIYMA freshman
Join Date: Aug 2006
Location: Singapore
Age: 41
Posts: 43


Rep Power: 100 hyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enough


iTrader: (0)



Default Re: mixing 4 ohm & 8 ohm speakers

it'll be connected to the same passive network but i can use component values, 4 ohm values for the 4 ohm side, and 8 ohm values for the 8 ohm side. so that should not be a problem yes?

i'm worried that the sensitivity / amplitude gets affected and i end up with difference in loudness between the 2 speakers. is that likely as well?

thanks for the quick reply!
hyun is offline   Reply With Quote
Old 08-25-2006   #4
DIYMA 500 Club
 
MarkZ's Avatar
 
DIYMA Addict
Join Date: Dec 2005
Location: ..........................................
Posts: 6,853

Rep Power: 183 MarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really nice


iTrader: (4)



Default Re: mixing 4 ohm & 8 ohm speakers

Quote:
Originally Posted by hyun
it'll be connected to the same passive network but i can use component values, 4 ohm values for the 4 ohm side, and 8 ohm values for the 8 ohm side. so that should not be a problem yes?

i'm worried that the sensitivity / amplitude gets affected and i end up with difference in loudness between the 2 speakers. is that likely as well?

thanks for the quick reply!
Amplitude will be effected by virtue of the fact that they're different speakers. But this would be true even if they were driven off different amplifiers. Look at the sensitivity of the drivers rather than the impedance to determine how you need to get the two speakers to mesh.
MarkZ is offline   Reply With Quote
Old 08-25-2006   #5
 
DIYMA Novice
Join Date: Oct 2005
Location: Martinique
Age: 27
Posts: 278

Rep Power: 113 torog will become famous soon enoughtorog will become famous soon enoughtorog will become famous soon enoughtorog will become famous soon enoughtorog will become famous soon enoughtorog will become famous soon enough


iTrader: (2)



Default Re: mixing 4 ohm & 8 ohm speakers

Great hyun!! I was just about to do a post on it! When you wire 4 ohms parallel you get 2 and in series you get 8. And when you wire one 4 ohms and one 8 ohm what do you get?? Thanks..
torog is offline   Reply With Quote
Old 08-25-2006   #6
DIYMA 500 Club
 
MarkZ's Avatar
 
DIYMA Addict
Join Date: Dec 2005
Location: ..........................................
Posts: 6,853

Rep Power: 183 MarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really niceMarkZ is just really nice


iTrader: (4)



Default Re: mixing 4 ohm & 8 ohm speakers

Quote:
Originally Posted by torog
Great hyun!! I was just about to do a post on it! When you wire 4 ohms parallel you get 2 and in series you get 8. And when you wire one 4 ohms and one 8 ohm what do you get?? Thanks..
1/(1/4+1/8) = 2.67

But when passive crossovers are involved, it's a different story. For instance, a 4 ohm tweeter in parallel with a 4 ohm woofer would give you roughly 4 ohms.
MarkZ is offline   Reply With Quote
Old 08-26-2006   #7
 
DIYMA freshman
Join Date: Aug 2006
Location: Singapore
Age: 41
Posts: 43


Rep Power: 100 hyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enough


iTrader: (0)



Default Re: mixing 4 ohm & 8 ohm speakers

Quote:
Originally Posted by torog
Great hyun!! I was just about to do a post on it! When you wire 4 ohms parallel you get 2 and in series you get 8. And when you wire one 4 ohms and one 8 ohm what do you get?? Thanks..
from what i understand, in a 2-way crossover, where the 2 (4 ohm) speakers are wired in parallel, this is what happens:

1. At the crossover point, the impedance has risen to double (8 ohms) due to the added impedance of the crossover components. (some crossovers increase impedance even more, and drop output by -6db at that point.) so u still get 4 ohm load at this point.

2. Above, and below this point, the impedance for the speaker that has its frequency cut off keeps rising, because the crossover components gain impedance the deeper into cutting territory it gets. the other speaker regains its base impedance (4 ohms) pretty soon outside this point. so the summation = 1/4 ohms + 1/high ohms (in parallel) = 1/net_impedance = about 1/4 ohms. therefore, 4 ohms is still preserved.

that's how u theoretically get a flat response ("constant" 4 ohms) with some types of crossovers.
hyun is offline   Reply With Quote
Old 08-26-2006   #8
 
Ignorance is Bliss
Join Date: Sep 2005
Location: Raleigh
Posts: 181

Rep Power: 112 af22 will become famous soon enoughaf22 will become famous soon enoughaf22 will become famous soon enoughaf22 will become famous soon enoughaf22 will become famous soon enoughaf22 will become famous soon enough


iTrader: (0)



Default Re: mixing 4 ohm & 8 ohm speakers

FYI:

The Focal utopias and K2P's,

The TN52/51 Tweeter is 6 ohms, while the midbass driver is 4 ohms, and it's tied on a passive crossover.

So i guess it's not that uncommon.

Currently Installed: Lexus IS300
Eclipse CD8455
Focal TN52| Seas W18NX Midrange | Seas Lotus SW300 Sub
Diamond Audio D7056 @ 50x2 tweeter, 100x2 midrange
Diamond Audio D7152 @ 600x1 subwoofer
af22 is offline   Reply With Quote
Old 08-26-2006   #9
Upgrade Your Membership!
 
DIYMA Founder
Join Date: Jul 2005
Location: California
Posts: 4,786

Rep Power: 160 npdang will become famous soon enoughnpdang will become famous soon enoughnpdang will become famous soon enoughnpdang will become famous soon enoughnpdang will become famous soon enoughnpdang will become famous soon enough

Send a message via ICQ to npdang Send a message via AIM to npdang Send a message via Yahoo to npdang

iTrader: (8)



Default Re: mixing 4 ohm & 8 ohm speakers

I think it's simpler if you look at it this way. For a 2-way crossover, the passive components act as a filter between the two drivers, such that each driver is playing only the frequency range you intend. The impedance of the drivers themselves will determine the value of the components you use. The driver's impedance never changes, and any differences in output can be dealt with by attenuating the louder driver with another filter.

A speaker is only as good as the room you put it in.
npdang is offline   Reply With Quote
Old 08-26-2006   #10
 
DIYMA freshman
Join Date: Aug 2006
Location: Singapore
Age: 41
Posts: 43


Rep Power: 100 hyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enoughhyun will become famous soon enough


iTrader: (0)



Default Re: mixing 4 ohm & 8 ohm speakers

therefore when designing a passive 2-way cross of mismatched ohm drivers, the filter on EACH side has to match its respective driver's impedance. it doesn't matter what's on the OTHER side, as long as the pass filter for that side concerned has been calculated correctly, it'll be fine.

i don't know the specs for sure of my tweeter. one way to guess what's the nominal impedance rating is to measure its DC Resistance, right? If I already see about 3.2-3.4 ohms DCResistance, it should be a 4 ohm tweeter. If I already measure a 5 ohm DCR it probably is a 6 ohm tweeter. Logical?
hyun is offline   Reply With Quote
Old 08-26-2006   #11
Upgrade Your Membership!
 
DIYMA Founder
Join Date: Jul 2005
Location: California
Posts: 4,786

Rep Power: 160 npdang will become famous soon enoughnpdang will become famous soon enoughnpdang will become famous soon enoughnpdang will become famous soon enoughnpdang will become famous soon enoughnpdang will become famous soon enough

Send a message via ICQ to npdang Send a message via AIM to npdang Send a message via Yahoo to npdang

iTrader: (8)



Default Re: mixing 4 ohm & 8 ohm speakers



It's probably more accurate to look at the driver's impedance near the crossover region.

A speaker is only as good as the room you put it in.
npdang is offline   Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
The "Real Deal" with 8 ohm drivers npdang How-To Articles Provided by our members 228 11-22-2013 02:03 PM
xtant 404m elminster Technical & Advanced Car Audio Discussion 15 06-16-2010 06:54 PM
new FS thread.. amps, speakers, subs, tools, assec. bdubs767 Car Audio Classifieds 3 12-01-2006 10:27 PM
Mixing 8 ohm and 4 ohm drivers Beau Technical & Advanced Car Audio Discussion 4 04-15-2006 05:28 PM
Question about a 4 ohm passive crossover and 8 ohm speakers tyroneshoes Technical & Advanced Car Audio Discussion 4 03-29-2006 02:28 PM

» Amps
A/d/s/
Advent
Alphasonik
Alpine
American Bass
ARC Audio
Atomic
Audio Art
Audio Gods
Audiobahn
Audiocontrol
Audiopipe
Audison
Aura
Autotek
Avionixx
Bazooka
Beyma
Blaupunkt
Boss
Boston Acoustics
Bravox
Cadence
Cascade (CAE)
CDT Audio
Cerwin Vega
Clarion
Clif Designs
Concept
Coustic
Critical Mass
Crossfire
Crunch
DB Drive
DC Audio
DC Power
DEI
Denon
Diabolo
Diamond
Digital Designs
Directed
DLS
Dual
DYnamat
Dynaudio
Earthquake
Eclipse
Elemental Designs
ESX
Eton
Farenheit
Fi Car Audio
Focal
Fusion
Genesis
Ground Zero
Hafler
Helix
Hertz
Hifonics
Hushmat
Image Dynamics
Infinity
Interfire
JBL
Jensen
JL Audio
JVC
Kenwood
Kicker
Knu Konceptz
Kole Audio
Kove Audio
Lanzar
Lightning Audio
Linear Power
MA Audio
Magnat
Marantz
Massive Audio
MB Quart
McIntosh
Memphis
Metra
Milbert
MMATS
Mobile Authority
Morel
MTX
Nakamichi
Niche Audio
O2 Audio
Ohio Generator
Optima
Orion
Oxygen Audio
OZ Audio
PG Audio
Phase Linear
Phoenix Gold
Pioneer
Polk
Power Acoustik
Powerbass
Powermaster
Precision Power
Profile
Pyle
Pyramid
RadioShack
Rainbow
Rampage
RE AUdio
Rockford Fosgate
Scanspeak
Scosche
Seas
Sony
soundstream
Sparkomatic
SPL Dynamics
Stinger
Sundown Audio
Swiss Audio
Targa
TC Sounds
TREO Engineering
TRU
Tsunami
Ultimate
US Acoustics
US Amps
Velodyne
Vifa
Viper
Visonik
Xtant
Zapco
Zed Audio
Powered by vBadvanced CMPS v3.2.3

All times are GMT -6. The time now is 12:01 PM.


Powered by vBulletin®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0
Powered by vBadvanced CMPS v3.2.3

Ad Management by RedTyger

Meet Our Team | Forum | Privacy and Rules | Advertise | Archive | Search | Contact Us

Home | User CP | Members List | New Posts | ITrader | Faq | Post Spy