+ Reply to Thread
Results 1 to 13 of 13

Thread: Speaker question

  1. #1
    madmikejt12 Newbie
    Join Date
    Sep 2005
    Location
    Liverpool (UK)
    Posts
    270

    Speaker question

    hi, for my car CD player in my room, I am looking for speakers... at the moment i use my logitech 2.1 which i also use for my PC (plugged into the RCA sockets on the cd player)

    The max. output per channel is 45W (4 channels)

    so, if i have 2 or 4x 100w speakers, will the player just provide each with up to 45W, or would it damage the cd player?

    and also, if i have 4x 10 or 20W speakers, will the CD player provide to much power to the speakers on a high volume damaging them?

    baisically, what wattage speakers can I use safely?

    Thanks,
    Mike
    I would like to say thank you to everyone who has helped me, I enjoy learning new things and eventually, i would like to be really good at electronics

    Mike


  2. #2
    kruno Newbie
    Join Date
    Feb 2007
    Posts
    6

    Hi Madmikejt12. It is always better to use spikers with higher watts than the max output power is! In your case it is good to have speakers of 70W or more.Higher wats will not destroy outputs but if you have less wats then the output is your speakers will be demaged.
    Bye, Kruno

  3. #3
    kruno Newbie
    Join Date
    Feb 2007
    Posts
    6

    Quote Originally Posted by madmikejt12
    hi, for my car CD player in my room, I am looking for speakers... at the moment i use my logitech 2.1 which i also use for my PC (plugged into the RCA sockets on the cd player)

    The max. output per channel is 45W (4 channels)

    so, if i have 2 or 4x 100w speakers, will the player just provide each with up to 45W, or would it damage the cd player?

    and also, if i have 4x 10 or 20W speakers, will the CD player provide to much power to the speakers on a high volume damaging them?

    baisically, what wattage speakers can I use safely?

    Thanks,
    Mike
    Hi,it is always better to have speakers with more watts than the output power is.In your case from 65 watts or more.Never put less watts than your output power is because it can damage your speakers and outputs too.
    Bye,
    Kruno

  4. #4
    madmikejt12 Newbie
    Join Date
    Sep 2005
    Location
    Liverpool (UK)
    Posts
    270

    Thanks for your reply

    100W it is then there is someone sellng some locally.... i will contact him.
    I would like to say thank you to everyone who has helped me, I enjoy learning new things and eventually, i would like to be really good at electronics

    Mike

  5. #5
    Blatman Bond Newbie
    Join Date
    May 2007
    Location
    Indonesia
    Posts
    113

    CD player can't drive speakers directly (without power amplifier). Your logitech is active speaker with built-in amplifier.

    The player output only small signal, less than 1 watt. So, If you have 2 or 4x 100w speakers (active speakers) no need to worry about the player. Most active speaker need very small input power.

    You need power amplifier if your speakers are passive.
    Otherwise the player already with power amplifier.

  6. #6
    audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent
    Join Date
    Mar 2004
    Location
    Canada, of course!
    Posts
    19,288

    The four speaker outputs of your CD player each provide 14Watts into 4 ohm speakers, or 45Whats. Whats are not Watts.
    If you use 8 ohm speakers then the power per channel is 8Watts.
    Uncle $crooge

  7. #7
    madmikejt12 Newbie
    Join Date
    Sep 2005
    Location
    Liverpool (UK)
    Posts
    270

    the speaker spec says:

    first 2 speakers:
    Power Rating: 100watts
    Sensitivity 86Db
    Impedance 4-8
    Shielded

    second 2 speakers:
    8 ohm, 100 Watts, Biwireable

    The CD player:
    http://www.electro-tech-online.com/a...f?d=1181952409

    ●Use ungrounded speakers only.
    Allowable input : 45 W or more
    Impedance : 4 – 8 Ω
    ●Distance between speaker and amplifier: 30 cm or more

    I want to know if it is safe to use 100w speakers connected to the amplified speaker outputs??

    My power supply is 350W
    Last edited by madmikejt12; 21st July 2007 at 07:04 PM.
    I would like to say thank you to everyone who has helped me, I enjoy learning new things and eventually, i would like to be really good at electronics

    Mike

  8. #8
    audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent
    Join Date
    Mar 2004
    Location
    Canada, of course!
    Posts
    19,288

    The Panasonic CD player has four outputs of 45Whats each into 4 ohm speakers.
    The speakers must be rated at 45Whats each or more.

    You found speakers rated at 100Whats which will be fine, except they are not 4 ohms so the power will be less than 45Whats each.

    I wish manufacturers would stop lying about power and specify real Watts.
    Uncle $crooge

  9. #9
    Sceadwian Excellent Sceadwian Excellent Sceadwian Excellent Sceadwian Excellent Sceadwian Excellent Sceadwian Excellent Sceadwian Excellent
    Join Date
    Oct 2006
    Location
    Rochester, NY U.S.
    Posts
    9,650
    Blog Entries
    1

    If the outputs are from a common signal shouldn't it be possible to bridge them for a higher ohm speaker?
    "Because I be what I be. I would tell you what you want to know if I
    could, mum, but I be a cat, and no cat anywhere ever gave anyone a
    straight answer, har har."

  10. #10
    audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent audioguru Excellent
    Join Date
    Mar 2004
    Location
    Canada, of course!
    Posts
    19,288

    The Panasonic CD player and all modern car radios use bridged outputs. That is why the owner's manual specifies speakers that are not grounded.
    They provide 14 Watts RMS per channel at low distortion into 4 ohms.

    If the outputs were not bridged then the output would be only 4 Watts per channel into 4 ohms. Some car amplifier ICs can drive about 7 Watts into 2 ohm speakers when not bridged.

    The power is less if the speaker impedance is higher. The output into 8 ohm speakers is only 2 Watts per channel if the amplifier is not bridged.
    Uncle $crooge

  11. #11
    madmikejt12 Newbie
    Join Date
    Sep 2005
    Location
    Liverpool (UK)
    Posts
    270

    ok, thanks for that it has cleared some things up!!

    could you just tell me the difference between Watts and Whatts?
    I would like to say thank you to everyone who has helped me, I enjoy learning new things and eventually, i would like to be really good at electronics

    Mike

  12. #12
    Blatman Bond Newbie
    Join Date
    May 2007
    Location
    Indonesia
    Posts
    113

    ●Use ungrounded speakers only.
    => don't connect any speaker cable to each other. Might be the amplifier is bridged.
    Allowable input : 45 W or more
    => 100 W is OK.
    Impedance : 4 – 8 Ω
    => both your speaker type is OK.
    ●Distance between speaker and amplifier: 30 cm or more
    => I don't know about this one, might be just suggestion for better sounding.

    What the differences between Whats and Watts?
    I agreed, that many manufactures are lying.
    Also 100 W speakers not always survive when they powered with 100 W.
    But 10 Watts is enough for small room and everyday listening.

  13. #13
    madmikejt12 Newbie
    Join Date
    Sep 2005
    Location
    Liverpool (UK)
    Posts
    270

    ok, thanks very much to everyone for your help!!
    I would like to say thank you to everyone who has helped me, I enjoy learning new things and eventually, i would like to be really good at electronics

    Mike

+ Reply to Thread

Similar Threads

  1. Capacitor Charge/Discharge question
    By ThermalRunaway in forum General Electronics Chat
    Replies: 25
    Latest: 12th August 2008, 05:48 PM
  2. Speaker Impedance Question
    By De1337 in forum Electronic Projects Design/Ideas/Reviews
    Replies: 76
    Latest: 26th June 2007, 04:54 AM
  3. Question about programming speaker to PIC 18F4520
    By Dallas in forum Micro Controllers
    Replies: 5
    Latest: 26th May 2006, 05:27 PM
  4. Speaker as microphone question...
    By ken3983 in forum Electronic Projects Design/Ideas/Reviews
    Replies: 1
    Latest: 1st September 2004, 12:23 AM
  5. speaker question
    By Moe the Bartender in forum General Electronics Chat
    Replies: 2
    Latest: 6th August 2004, 06:33 AM

Tags for this Thread