Ohms and speakers Questions

[crackhead2k]

Would running a speaker at 6 ohms that is rated for 8 ohms damage it?
moderate volumes say polk audio rti a3?

[whatever]

How who`d you run a 8 ohm driver at 6 ohm ?

You might want to say that your amplifier has been designed to drive 6 ohm speakers and you want to find out how it will handle your 8 ohms speakers. right ?

[[XC] leviathan18]

yeah you cant run the speaker at lower ohm its rated lol just the amp and if the amp is rated at xxx W at x ohm everything above that will make less power but it will work fine if you go lower from rated the amp you can damage it as it will make more power

[whatever]

You could try. The speaker impedance varies, isnt constant. Low frequencies -> low impendance (at FS you`ll have Zmax), high frequency-> high impedance. Simple.

Keep in mind not to give maximum power.

[cadaveca]

OK, 6 ohm is the "de-facto standard" for high-end speakers and amps.

Most mid-range amps are 6 ohm as well, but most mid-range and low-range speakers are 8-ohm.

So, let's have an example. My stereo is 4, 6 or 8 ohm. @ 8ohm, it will do 135w, but at 6ohm, it will do 200w. There is a switch on the stereo that enables this function. the manual itself will tell you, if running both the A & B front outs at the same time, to run 6ohm. If you do not overcurrent protection will kick in(running A&B together @ 8ohm produces 4 ohm load, stereo cannot handle this in 5ohm mode).

Not that this really answers your question, but it will give you some info. :shrug:

[STEvil]

Your amp/receiver is what will matter.

Find out if it is rated at 4, 6, or 8 ohms.

If the speaker you are using is rated equal to or higher than what the receiver is rated at then you have nothing to worry about.

[crackhead2k]

The reciever is a HTR-6160(yamaha). 95watt per ch. Options on receiver 6ohm/8ohm.

[cadaveca]

set to 6ohm. STEvil jsut said what I wanted to say, but far more elegantly. I have yamaha 6180 hooked up my pc, set to 6-ohm. I'm not sure if
your has "presence" speakers, but this is why I have my stereo in that mode.


EDIT: Make sure you hook up TWO subs!!! stereo splits low-range into left and right! Don't use the included mic to set your stereo up!!! Measure speaker distance and set that way!!!! ;)

[nike]

thanks for that STEvil.
ill save that knowledge :p:

[crackhead2k]

Min. RMS Output Power Front Channels 95 W + 95 W (0.06% THD)
(8 ohms, 20 - 20,000 Hz) Centre Channel 95 W (0.06% THD)
Surround Channels 95 W + 95 W (0.06% THD)
Rear Surround Channels 95 W + 95 W (0.06% THD)
Dynamic Power (8/6/4/2 ohms) 130/165/195/240 W
Damping Factor (8 ohms, 20 - 20,000 Hz) 120 (Main)
Frequency Response 10 Hz–100 kHz +0/-3 dB
Total Harmonic Distortion (CD, Front Sp Out) 0.06% (50 W/8 ohms)

the rti are 8 ohms they start sounding at bit weird at 6ohms. I'll leave the receiver at 8 ohms. On the specs it says dynamic power and 2.4,6....ohms and there is not option for that(2/4ohms) on the reciever settings. Mind explaining?

I'm not sure if
your has "presence" speakers
Yes it has presence speakers and I plan on using them as presence speakers when I get the floor/ subs etc..........
----------------------rti a3 specs-------------------
Electrical
Overall Frequency Response 40Hz-27kHz
Lower -3dB Limit 50Hz
Upper -3dB Limit 26kHz
Nominal Impedance 8 ohms
Recommended Amplifier Power 20-125 w/channel
Efficiency 89 dB
Crossover 2.8kHz, 12dB/octave high and low pass
Inputs 5-way binding posts
----------------------------------------------
I guess I should of added earlier... So I guess its safe to say the specs on the speakers are higher in terms of watts? but ohms?

btw my speakers are bi wired atm

[[XC] 2long4u]

If you use a lower Ohm speaker it will just draw more power out of your amp. Most 8ohm speakers I've checked ohm out at 6.
It's not a big deal. If you run a speaker with a bad surround you can short the voice coil and that's when you would have a very low ohm reading. If you used that speaker it could ruin the amp.

[cadaveca]

Min. RMS Output Power Front Channels 95 W + 95 W (0.06% THD)
(8 ohms, 20 - 20,000 Hz) Centre Channel 95 W (0.06% THD)
Surround Channels 95 W + 95 W (0.06% THD)
Rear Surround Channels 95 W + 95 W (0.06% THD)
Dynamic Power (8/6/4/2 ohms) 130/165/195/240 W
Damping Factor (8 ohms, 20 - 20,000 Hz) 120 (Main)
Frequency Response 10 Hz–100 kHz +0/-3 dB
Total Harmonic Distortion (CD, Front Sp Out) 0.06% (50 W/8 ohms)

the rti are 8 ohms they start sounding at bit weird at 6ohms. I'll leave the receiver at 8 ohms. On the specs it says dynamic power and 2.4,6....ohms and there is not option for that(2/4ohms) on the reciever settings. Mind explaining?

Yes it has presence speakers and I plan on using them as presence speakers when I get the floor/ subs etc..........
----------------------rti a3 specs-------------------
Electrical
Overall Frequency Response 40Hz-27kHz
Lower -3dB Limit 50Hz
Upper -3dB Limit 26kHz
Nominal Impedance 8 ohms
Recommended Amplifier Power 20-125 w/channel
Efficiency 89 dB
Crossover 2.8kHz, 12dB/octave high and low pass
Inputs 5-way binding posts
----------------------------------------------
I guess I should of added earlier... So I guess its safe to say the specs on the speakers are higher in terms of watts? but ohms?

btw my speakers are bi wired atm

Ah, with presence you should not bi-wire. But that's the cause of your sound issues(bi-wired 6-ohm). I have the level up from your stereo, so mine puts out a bit more grunt than yours(although most often all that changes with yamaha between models is video function).Bi-Wire requires 8ohm.

You can either 7.1, 5.1 with presence, 5.1 with second zone, or 5.1 bi-amped fronts. Only the top-level amps($1200+) actually have 9 amps within them, so you must decide how you want the 7 amps inside your reciever to work.

You must set the speaker OHM rating by pushing some buttons when powering on. Check the manual for how to do it. Dynamic power means that at lower volumes, it will not use the full potential, but crank the volume up to 0.0DB, and it will use most, and you should have 16-20DB+ over 0.0DB for "overdrive". It's dynamic in that you can change those levels lower if you adjsut the volume.

In regards to the presence speakers....


Ok, so if you do real theatre quality editing, you'll have 4 fronts, and then surrounds. Presence trys to duplicate this, but I find that the sonic reproduction over the presence channels is pretty useless...mostly out-of-phase sounds to widen the soundstage. I get far better sound with 4 fronts, but in this config, speaker placement is paramount, and doesn't work well with my room.


Mic set-up is flawed, as it assumed a closed room, and I have a 980sq ft room with my pc in one end. The calibration mic ended up setting to open side far too loud(+6db).


Anyway, those specs listed by Yamaha are not correct..they are actaully about 5-10% lower than what the amp is realyl capable of...so enjoy it!

[STEvil]

Yamaha builds awesome stuff ;)

I much prefer 4 mains to presence. I also tend to use "oversized" rears that can keep up to the mains too though ;)

[cadaveca]

Front to back around my PC is 26ft. Soundstage is set at 12ft wide, speaker every 3 ft. Great for gaming, with sides @ 11 FT away from my sitting position @ 45 degrees. Rears are almost 20ft away when sitting at pc, so yeah, they need a bit more grunt, but almost nothing uses them anyway, besides Bluray content, and then my sitting position is in the middle, with almsot every speaker besides teh sides aprpox 12 FT away(sides are 5.5ft away then, @ 90 degrees). There's still almost 30ft x 20ft open beside my set-up, and there's no issues with sound reproduction this way using the yamaha, when many other receivers i tried had very large holes in the soundstage when in this room. that speaks volumes as to how good the stereo really is...

[[XC] 2long4u]

Yamaha huh? Look into getting a CR2020.

[cadaveca]

Already have one. ;) Was my grandfather's amp.

[crackhead2k]

Anyway, those specs listed by Yamaha are not correct..they are actaully about 5-10% lower than what the amp is realyl capable of...so enjoy it!

Should I have bought another receiver? or is most specs from manufactures have it rated up 5-10% too?
What should I set my volume/wave on my sound card for best sound on my receiver, im using a optical out, btw Sound card is (HTO STRIKER 7.1)
If there is any optimizations you recommend or upgrades to make it fit nicely with the speakers/receiver that would be great.

I don't know of any sound card specially made for sound/home theater any input on this would be useful. =)

And thanks for the info cadaveca:up:

[cadaveca]

Actually, most other receiver specs listed on manuals, etc, are higher than what the product is capable of. Yamaha is the outsider, in this regard, especially with any other product within your amps price range. most others will say 100w-125w, but will only be capable of 75-80 before clipping.

I have volume set to max, with a good sound card this should not introduce any distortion(TBH, I do not like the striker 7.1, far too much bass, very "digital" sound because of the lack of midrange presence.). But I'm eagerly awaiting the Xonar HDAV myself to replace my Xonar D2X, and it features rca-outs for just this purpose. Get that sound card, use your pc for HD content with HDdvd/BDrom, and you'll never need another sound solution for home theatre. I'd simply look at some better speakers...not that your are bad or anything, just not to my personal liking. I won't ever buy a speaker with bass port directed to the front except a sub...but like I said, personal preference. Bass is always better re-directed off of a wall, and you'll find most audio "experts" have the same opinion...I tried, and will never go back to front ports.


Bought another receiver? Nah, the one you got is very good, and very capable. The fact that it will do far more than what Yamaha rates it for is a good thing, not a bad thing!!!!:fact: The video-side of the amp is not to my liking, but I don't use it anyway, and I'm VERY PICKY in this regard. I don't have a big-screen TV, my home theatre is my pc itself, at least at this point, simply because of issues with HD content, device compatibilty, and more importantly, because of HDMI.


The amp is capable of more than your speakers, supposedly, but as long as your audio is pure, you have no worries. I have yet to experience clipping in my amp, I typically run -30DB for music, -20DB for movies, leaving 36-46db still available to make me go deaf. I use 2 subs, at very low volume(two fill the room, which is only 1/3 pc space), and have yet needed to put volume higher, even with 4 kids sitting with me excited about Harry Potter.



But more on your speakers...if you have the bookshelfs, don't bi-amp them. Floors, with mid/tweet on crossover, and subs seperate, ok, but never on a bookshelf in that price range. See the Polk LSi series for what I mean about bass ports, and bi-amping...the speaker design makes it clear as to what is expected in high-end audio when it comes to that...even why you would bi-amp is pretty clear just by looking at them. Anyway, single-amp them, you stereo is more than capable of single-amping those bookshelf speakers till they burn out, and bi-amping them will only introduce speaker limits before amp limits.


Edit:

straight from your speaker's manual, I bolded why I just had to post it, although it DOES agree with what I'm saying...:



Automobile horsepower is good analogy. Your car probably has far more horsepower than it needs for your daily commute and is likely capable of going well over 120mph (190km/hr). Having that extra power is good for on-ramp acceleration and danger avoidance (like getting away from brain-eating zombies :ROTF:) but that doesn’t mean that it is advisable to operate your car on North American highways at full power and maximum speed for an extended period of time. Just ask your local state trooper
if you are in doubt. Similarly, we recommend using amplifiers and receivers with rated power above the Power Handling limits of our speakers because having extra power available for short term peaks is conducive to better sound quality, maximum dynamic range and effortless high volume output. But we strongly urge you not to use the full power of your amplifier or receiver for daily listening.

[crackhead2k]

The amp is capable of more than your speakers, supposedly, but as long as your audio is pure, you have no worries. I have yet to experience clipping in my amp, I typically run -30DB for music, -20DB for movies, leaving 36-46db still available to make me go deaf.
The controls on the Audio Configuration only shows slider bars and not in "DB" for my sound card =/
For Audio being "pure" you mean CDs non-compressed/FLAC?
Why is there a "Wave" and a "Volume Control" what the purpose? It feel like there both the same thing.... It is like wave isn't really needed. Some music seems to sound better when I leave the volume around 40-60% and not sound so bright on my speaker.
and last thing is it better to turn the volume down in the PC and let the Receiver raise the volume?

I do really like the speakers, I can hear every detail. My previous speakers are the z5500 and it beats the crap out of them except in bass since I don't have a dedicated Sub yet >.>" The speaker is very good in the higher end frequencies although I haven't listen to other higher end audio.
If I were to buy a LSi9 and its 4 ohm could I just leave my receiver at 8 ohms? would there any problems? It wouldn't kill my receiver would it?
I don't listen to music excessively loud, may some movies I watch may have good parts were I raise the volume to hear the "punch" >.>

[cadaveca]

The DB rating is from my reciever...sound card volume is maxed. The problem you have with pc volume is due to your sound card. Wave is a sound codec, .wav, like .mp3, but it's abilities in sound recording far exceed any other format pretty much, lossless, but using .wave files will easily show a sound card's weakness, and this is what you are experiencing...it's not Windows, your amp, or speakers, just the card that isn't quite up to snuff(you must admit, it's a fairly cheap card). You better off to have the wave volume high, and pc volume high, then use your reciever to control volume, as it should be doing ot processing anyway, over digital connections...have a lower volume in the pc means that your sound is also partially processed by the card...which kind of negates the purpose of using a digital connection!

In regards to teh LSi9, I would have to check the manual, but it's stated in there what to do. I will sat, however, that when buying home audio, especially in the mid-high and high-end, you pick your speakers first, adn tehn buy an amp to match the speakers. The LSi series top model is around $2500 per speaker, bookshelf variants are about $1000...so you are looking at a good $10k on speakers alone...to run them on that amp would be a shame!!!(but it would still sound good!). So, for those specific speakers, running 4-ohm is a must. But it may also be possible to bi-amp that speaker @ 8ohm...I am not sure, the speaker was merely an example, and not one I perosnally would recommend.

PC speakers suck, no matter the speaker, beecause each and every one is lacking in mid-range power. You hear more sound, becuase, truly, more sound is coming out of the speaker!!! Don't make judgements based on that comparison...

[[XC] 2long4u]

How bout a Sansui 9090?

[STEvil]

-snip-Rears are almost 20ft away when sitting at pc, so yeah, they need a bit more grunt, but almost nothing uses them anyway, besides Bluray content-snip-...

All the audio codecs out there suck as far as i'm concerned...

[crackhead2k]

My previous speakers are the z5500 and it beats the crap out of them except in bass since I don't have a dedicated Sub yet >.>"
Sry made a mistake here.... I meant my receiver with my polk audio speakers beat the crap out of the z5500....... haha I was just typin away on the my last post.

So my receiver isn't 4 ohms capable? I'm so confused with the "ohms" stuff. That and then there's watts.....

Or is it every receiver CAN do 4 ohms it just doesn't have enough watts? or is it a watts thing? What does ohms have to do with speakers electrically? and one thing I missed.... Its bi amped not bi wired. I think in one of my earlier posts I wrote bi wired. Don't know if that makes a difference.

Let me get this straight since my understanding is not very good....with ohms
Ohms is just resistance and therefore need to draw more power to reach the same volume of a 8 ohms speaker? (probably due to the speakers?)
So when I say power is that watts? So if I set my receiver to 8ohms what does that actually tell the receiver to do? and If I put a 4ohm speaker on will it just won't have enough power to run it at its best because of the resistance or is there something electrically that I still have to know about ohms and its effects?

Sry for being a nub I had a 3-4 hours crash course before buying this receiver and speakers. Quite happy though (Bi amped, 14 guage wiring ->may upgrate wire later, 8ohms)
btw, if I damage the amp with improper setting it means no sound or bad sound quality?

Definitely going to upgrade my sound card to a asus xonar, my current sound card is definitely holding me back >.>

Really appreciate your help guys! :yepp::up:;)

[cadaveca]

You won't damage teh amp, it will just shut itself off.


I highly suggest to read your stereo manual...alot of your questions will be answered there. IT CAN do 4ohms, but you must set the amp to 6-ohm mode to enable this.

Anyway, when it comes to WATTS...ignore that. NOt all manufactureres rate their stereos i nteh same fashion, hence the Yamaha amps being underrated, and almost everything else overrated. However, if you REALLY look at het specs, the amp is rated @ 95w per channel, but listed power is 130w @ 8ohm. yamaha stereos will do thier maximum rated power(the 95w) 24/7(RMS rating), where as others list what they can PEAK at(the 130w).

A speaker is a magnetic feild generator. This field will move the voice coil, pushing the air in a frequency that creates the sound. That's why larger speakers put out more volume, generally...they move more air.

SO, in creating that field, it pulses, but in order to drain the field quickly, ground must be connected, and as such power will be returned to the amplifier. The OHM-rating basically "tells" the amp how much power it must deal with coming back, and if it is not prepared, it can be overloaded. This is what happens when running the wrong rated speaker at the wrong setting, and alsmot every amp out there today is prepared that should things overload, it quickly shuts down to prevent starting a fire!

[[XC] 2long4u]

I never thought about using the receiver for computer speakers. Do you just get a 1/8" plug to rca's?

[STEvil]

Pretty much.

My headphone amp is a Yamaha RX-495 lol ;)


Anyways i'm going to attempt to sort this out a bit for you.

The amplifier/receiver generally has several ohm loads it is capable of running. Some require you to adjust a switch or setting to change between them, some dont. Generally all this switch does is change the voltage output by the driver mosfets within the amplifier (Volts*Amps = Watts). This means that at 4 ohms or 8 ohms your amp may be putting out 10 amps of current but at 8 ohms will do this with 50 volts and at 4 ohms do it with 50 volts providing the same power output (or near). The ohm load of your speaker is a reactive load. When the speaker is in operation the ohm load presented to the amplifier constantly changes. The ohm rating of the speaker is generally just guideline so you dont go connecting a 1 ohm speaker to an 8 ohm only source. Most speakers if you measure them are actually .5 to 1 ohms lower than their rated value when not in use (not connected to anything, no power to them).

Important things to note is that amplifiers with an A speakers and B speakers may combine these internally which means putting two 8 ohm speakers (one on A, one on B) will produce a 4 ohm load to the amplifier. To further explain the mess of ohm loads you need to look at the power source (mosfets) again. The produce a voltage output based on where you have the volume knob. Lets say this is 50 volts at 50% volume and 8 ohms. If you attach a 4 ohm speaker in place of the 8 ohm speaker your mosfets will increase voltage output. They may be putting out 75 or 80 volts now which may be out of their tolerance levels for more than peak power. Some amps automatically adjust the internal circuitry based on what is connected. Many do not.

Lastly you need to know how to read the power levels (R.M.S, Peak, P.M.P.O).

RMS stands for Root Mean Square and is the maximum power the amplifier can sustain without clipping (a clip is a square sine wave which causes distortion and may lead to speaker or amplifier failure) for a set amount of time (used to be something like 2 hours). This is clean power.

Peak power can be inflated from RMS by an amount anywhere from 25% to 150% (more than double the RMS value!). It used to be a value measured at or below 10% THD (Total Harmonic Distortion) which is about the point the average person can start to hear a speaker or amplifier clip or produce muddy sound. This is not a recommended number to go by when buying or installing audio equipment.

PMPO I saved for last because it is the worst. It often exceeds the Peak power measurement by factors of 10 or more. It is a pure marketing number and anyone you see using it you should steer clear of.. or better yet go laugh in their faces ;)


Read your manual, learn what you have on hand! ;)

[crackhead2k]

Thanks for the info Stevil!