Announcement

Collapse
No announcement yet.

House Speakers In Vehicle

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • House Speakers In Vehicle

    I wanted to say hello as this is my first post. I found similar post in your forums. I work in the IT field but am not a guru in car audio. I have two sb-cr99 house speakers. I was interested in putting them into my vehicle to save having to buy subs. I don't believe they are driven by a built in amp, so I assumed this should be easier. They are rated at 8 ohms. What could I do to get them running? Here is a spec sheet on them (listed to far right). I'm really only interested in using the 15" subs. What type of equipment would you recommend if this is possible? Any advice would be appreciated.Thanks and have a great day.


    Click image for larger version

Name:	101339-4-2.jpg
Views:	1
Size:	151.3 KB
ID:	2309513

  • #2
    House speakers in the main are 8ohm (as yours are).

    Car speakers and amps are generally anything from 1.2 to 4 ohm depending on manufaturer (4 ohm used to be the more common)


    What issues would this cause?

    Well the resistance of the house house speakers is higher, so it would need more power from the amp to get the same volume, which would put more stress on the amp.

    Depending on the quality of the amp and tolerances it may cause the amp to fail.


    You would need to check the specs of any amp you plan to use to see if it can handle 8ohms.

    I'm sure soundman will along soon to clarify more. (and probably disbunk the above)

    Comment


    • #3
      John Boehner on the right, Nancy Pelosi on the left and then you......oh, not that kind of House Speaker?

      Comment


      • #4
        Thanks. So essentially if I find a car amp that can handle 8 ohms I would be ok theoretically? I don't even know if these would sound ok as they are 200w by the spec sheet. I'm just tired of looking at them lol.

        Comment


        • #5
          Originally posted by Enforcer View Post
          I'm sure soundman will along soon to clarify more. (and probably disbunk the above)
          apparently i'm a force to be reckoned with?

          Originally posted by Enforcer View Post
          House speakers in the main are 8ohm (as yours are).
          kind of-- while 8 ohm is a typical average, i've seen anything from 4-32 ohm speakers used in various locations in houses..

          Originally posted by Enforcer View Post
          Car speakers and amps are generally anything from 1.2 to 4 ohm depending on manufaturer (4 ohm used to be the more common)
          yep.


          Originally posted by Enforcer View Post
          What issues would this cause?

          Well the resistance of the house house speakers is higher, so it would need more power from the amp to get the same volume,
          correct so far. but the nifty thing about higher-ohm speakers is that they are more sensitive to different audio signals. so whatever you loose in raw output, you'll gain in clarity. for the most part, it is really hard to tell much of a difference between a few hundred watts of power, so at the level of this speakers case-- 200 watts, it's really not much of a issue-- a 4 ohm or 8 ohm sub is going to sound about the same.

          Originally posted by Enforcer View Post
          which would put more stress on the amp.
          actually, it's backwards. less resistance puts more strain on the amp, but more resistance makes the amp happier and run cooler. it is always ok to run a higher resistance then whatever the amp is rated for, but rarely ok to run a resistance lower then what they are rated for.

          Originally posted by Enforcer View Post
          Depending on the quality of the amp and tolerances it may cause the amp to fail.


          You would need to check the specs of any amp you plan to use to see if it can handle 8ohms.
          nah, just pick a amp that rated at roughly 200w rms at 4 ohms and run with it-- i don't believe there are even any car audio amps rated at 8 ohms anymore. they're all pretty much rated at 4 and 2 ohms..



          but with all that said, expect to get mediocre bass. i've done it in the past with a old set of h.h.scott 15" 3-ways i've got laying around, in the back of a truck.. it's alright bass, about what compares to any mid-grade 10" car audio sub in a correctly-sized box. i understand wanting to try to use what you've got on-hand, and they will work, but there are more efficient solutions that don't take up as much space, and get the same result
          My OLD 2001 Mitsubishi Eclipse GT:
          "The Project That Never Ended, until it did"


          next project? subaru brz
          carpc undecided

          Comment


          • #6
            As stated above, higher impedance speakers are not an issue. It's only an issue if you use a speaker rated at LESS than the amps stable impedance. So if the amp is stable at 4 ohms, you can't run a 2 ohm speaker, but you can run 8 or even 16.

            Power = volts x amps
            Amps = volts / resistance

            So the higher the resistance the less current is required, so the less power is used.

            Comment


            • #7
              Originally posted by soundman98 View Post

              kind of-- while 8 ohm is a typical average, i've seen anything from 4-32 ohm speakers used in various locations in houses..
              Hence I said 'In the main'




              Originally posted by soundman98 View Post


              actually, it's backwards. less resistance puts more strain on the amp, but more resistance makes the amp happier and run cooler. it is always ok to run a higher resistance then whatever the amp is rated for, but rarely ok to run a resistance lower then what they are rated for.
              I was also going to mention about less resistance as well, but I forgot about it whilst typing. duh!



              As an addendum, I have run Home speakers in the car on a few occaisions. But I was using an amp that was designed for either 4 or 8ohm speakers each time.

              I once had a Realistic Pro2 speaker in the back of an old Ford Sierra. But had to take it out as it make the number plate on the back rattle too much.

              Also heard of someone ripping the back seats out of a beatle and replacing them with two Realistic Mach Twos.

              Comment


              • #8
                there is a way to solve the issue of having 8 ohms speakers hooked up to an 4ohm rated amp.

                here it goes,

                if you connect any 2 speakers in series (+ wire from amp ground to + wire of 2nd speaker and ground of 2nd speaker to amp) on one single channel you will double the resistance

                if you hook 2 speakers parallel on one single channel you will cut the resistance in half series being both sets of wires hooked up to a single channel.

                so if you connect both your speakers to one channel you should have a total of 4 ohms resistance.

                hope this helps


                p.s.

                this will work for all speakers provided you use 2 speakers with the same resistance, so dont go hooking up a 2 ohm and a 12 ohm speaker to one single channel hoping you get away with it because the 2 ohm speaker will blow and after that the amp will blow



                and the deal with resitance is as follows,


                the higher the resistance the more your amp has to work to get your speaker working

                BUT if you hook up a 2 ohm speaker to a 4 ohm amp you will have short life on your speaker, because the amp will demand too much from that speaker.

                it basically comes down to using the above if you want to hook up speaker rated different than your amp.

                for 2 ohm speakers on a 4 ohm amp you use series to double the resistance to 4 ohm

                for 8 ohm speakers you use parallel to cut the resistance in half

                all of this must be done on one channel , since all channels are rated in resistance seperately
                Last edited by eugenweij; 11-16-2012, 08:43 PM. Reason: clarification
                View my worklog here

                Comment


                • #10
                  Originally posted by eugenweij View Post
                  there is a way to solve the issue of having 8 ohms speakers hooked up to an 4ohm rated amp.

                  here it goes,

                  if you connect any 2 speakers in series (+ wire from amp ground to + wire of 2nd speaker and ground of 2nd speaker to amp) on one single channel you will double the resistance

                  if you hook 2 speakers parallel on one single channel you will cut the resistance in half series being both sets of wires hooked up to a single channel.

                  so if you connect both your speakers to one channel you should have a total of 4 ohms resistance.

                  hope this helps


                  p.s.

                  this will work for all speakers provided you use 2 speakers with the same resistance, so dont go hooking up a 2 ohm and a 12 ohm speaker to one single channel hoping you get away with it because the 2 ohm speaker will blow and after that the amp will blow
                  need to correct that last point-- you can connect any resistance to another resistance, but it is not recommended because the parameters of the speakers will be different-- the higher resistance speaker will have more voice coil windings in the magnetic gap, meaning they are more efficient at using lesser amounts of power.

                  speaking strictly on a weather the setup will emit audio or not-- it will work-- in the example you listed, you'd connect them in series for a overall load of 14 ohms. connecting them in parallel should net a resistance of about 1.7 ohms, which is really too low for even 2-ohm stable amps.

                  but audio-wise, it'd wreak havoc on the system, and there'd be a lot of peaks and cancellations throughout the spectrum over the speakers usable range, which is the main reason why you'd never want to use a setup like that.


                  but because you'd hook them up in series, as long as both speakers were physically designed to handle the power of the amp, there would be no reason for anything to fail.



                  Originally posted by eugenweij View Post
                  and the deal with resitance is as follows,


                  the higher the resistance the more your amp has to work to get your speaker working
                  nope. it's the other way around. amps are always more comfortable with a higher resistance load then a lower resistance load.

                  this is actually really easy to prove if you've got the extra equipment for it-- connect a high resistance load to a amp(connect a few 8 ohm speakers in series), and run it at a high level for a hour or 2. then let it cool down, and perform the same test with a single 4 ohm speaker for the same amount of time.

                  the amp will be hotter with the 4 ohm speaker.



                  Originally posted by eugenweij View Post
                  BUT if you hook up a 2 ohm speaker to a 4 ohm amp you will have short life on your speaker, because the amp will demand too much from that speaker.
                  opposite again
                  a setup like this drastically affects the amps lifespan much more then the speakers lifespan, because the amp has to work 2x's as hard as it was rated to work.

                  Originally posted by eugenweij View Post
                  it basically comes down to using the above if you want to hook up speaker rated different than your amp.

                  for 2 ohm speakers on a 4 ohm amp you use series to double the resistance to 4 ohm

                  for 8 ohm speakers you use parallel to cut the resistance in half
                  this only applies if you are attempting to perfectly match resistance to get a certain output level, or certain wattage. for the most part, it doesn't really matter, and the higher efficiency of higher-resistance speakers usually make up for most of the 'loss' that has occurred from the change in impedance.

                  Originally posted by eugenweij View Post
                  all of this must be done on one channel , since all channels are rated in resistance seperately
                  that's a very broad statement, and a dangerous one at that. there are many amps that are bridgeable, many that aren't, and just as many mono-channel amps.

                  if the amp is bridgeable, i recommend bridging it-- as long as you can meet the minimum resistance requirement, as it is typically double the normal, single channel output.

                  but plain, and simple, it's not something that can be covered in a blanket statement-- it's something that should be covered with amp selection.

                  Originally posted by Enforcer View Post
                  in addition to the above.

                  It is not good practice to use just one channel of a two channel amp.
                  would you happen to have anything to back that up? i guess in theory it could cause issues with uneven thermal loading on a amp, but i can't seem to find any info right away that shows that using a single channel off a multi-channel amp negatively affects the amp, or the audio quality..
                  My OLD 2001 Mitsubishi Eclipse GT:
                  "The Project That Never Ended, until it did"


                  next project? subaru brz
                  carpc undecided

                  Comment


                  • #11
                    Originally posted by soundman98 View Post
                    would you happen to have anything to back that up? i guess in theory it could cause issues with uneven thermal loading on a amp, but i can't seem to find any info right away that shows that using a single channel off a multi-channel amp negatively affects the amp, or the audio quality..
                    Used to work for Tandy in the UK.

                    Have had people come in with blown amps when they have done just that.

                    I think it depends on how the amp is wired/designed.

                    Some are wired as two totally individual amps per channel, but some seem to be wired together in some way.

                    Comment


                    • #12
                      The next paragraph had been moved from the last line in this reply since the rest was incidental being merely comments on "stress & strain" etc.
                      However that was before soundman's last reply. But I think we concur. Besides, some amps can be bridged for higher impedance loads. And those that can't can usually be fitted with bridging kits - eg,signal inverters.
                      But back to my original reply....

                      That brings me to my only relevant comment in this thread, namely that often domestic speakers are not suited to vehicles for environmental reasons - heat, vibration, etc.
                      But subs and their enclosures are probably fine - bass vibration generally being worse than g-forces and bumps - provided they handle the heat, or sunlight if exposed.



                      Nice thread. And I'm far from expert on audio.
                      In fact a relatively recent learning was that "unconditionally stable" at an Ohmage meant it would handle anything above - eg, a "1 Ohm" amp will handle 2, 4, 8 Ohms etc.
                      Yes - it's less power, but supposedly fine. (In theory, power decreases by the resistance ratio, eg 8 Ohms will be 2/8 = 1/4 the power output of a 2 Ohm speaker. I also read that "all good amplifiers" exhibit such behavior - not that I see many car amps that do [maybe varying SMPS voltage?].)
                      I must have been working on too many "tuned" amplifiers where the output impedances were matched, eg transmitters and maybe old audio circuits.

                      But hence IMO the speaker is seen simply as a resistive load, and hence the higher the resistance, the less the current (and less power).
                      But thus one point - there is no added stress or strainn on the amplifier because of a higher resistance load/speaker. There is less current, hence generally longer component life and less heating.

                      [ At least this should be easier than my usual alternator related discussions when many often say adding caps (why?) or bigger batteries increases the alternator's strain, but they're not considering the long-term. It's the opposite that is true - bigger batts etc decreases the "strain" - it saves the alternator having to replace the extra 30% of battery inefficiency used whenever it discharges. And the batt supplies the shortfall instead of the alternator - isn't that less strain?

                      And as to "strain" - is that appropriate? Is a 1Ω amp strained supplying its spec'd power to a 1Ω load? Is it more strained than on a 2Ω load? For a component POV, IMO yeah, they are more electrically stressed supplying twice the current into the 1Ω load, but to suggest that is bad if that is what the amp is rated and intended to do, but I consider neither a "strain" if strain is a negative term meaning an undesirable state. Different if we were discussing extending life, but we aren't - we are either into rated life & performance, else whatever life given our needs. (Ergo, a 90A alternator outputting 80A instead of 70A is not suffering increased strain.) ]



                      Nice too to read again the higher the Ohmage (speaker) the better the sound. I've read so many times in (car audio) forums that "the lower the Ohmage, the better the sound". What - less sensitivity is better? I think they mean power output, ie more power (with more distortion).
                      Some will know my views on having the PSU integral to the amplifier. Even worse is the reduction in speaker impedance from the olde norms of 4 to 16 Ohms etc, though I guess fatalities need to be minimised at very high power outputs (above ~1kW per speaker?). Maybe one day I'll have an engine bay PSU sending HV to a remote amp that drives higher Ohmage performance speakers (as in live-gig musician performances - maybe a few Marshalls or Fender bass speakers in the back?).


                      And now to implement some executive writing... (LOL - I moved the next to up top.) Oh no - intervening replies!!!

                      Comment


                      • #13
                        Just to clarify as it seems to be a little confusion in some of the posts... speakers are NOT seen as a resistive load. They are an inductive load (voice coil is an inductor, not a resistor). The rated impedance of say an 8 ohm speaker is given at a specific frequency of generally 1KHz (from memory). This will vary as the frequency varies which it does with audio!

                        Comment


                        • #14
                          I agree. Just use impedance instead of resistance in my reply, it makes no difference.

                          Alas I sometimes get told off for using impedance instead of the less complicated resistance (LOL- by similar people to one that argued that "Watts-RMS" is a misnomer (true, but it's so people know it isn't peak Watts) and proposed "Continuous Power" instead - without definition - and themselves measuring Vrms & Irms, hence no "Watts" involved - they were measuring VA!).

                          The impact of a speaker inductance (and capacitance) is shown by their impedance dependance on frequency.

                          Comment


                          • #15
                            I agree on the single channel issue , it is possible but you will end up with mono , thats why I recommend using 2 channels, and yes that is not the case for a bridgeable amp.


                            and for a more elaborate explanation of ohms click here



                            when reading that myself this morning it looks like I may have switched some things around while I typed my previous reply late last night
                            View my worklog here

                            Comment

                            Working...
                            X