Speaker Impedence

Discussion in 'Audio Hardware' started by Joey_Corleone, Apr 14, 2015.

Thread Status:
Not open for further replies.
  1. Joey_Corleone

    Joey_Corleone Forum Resident Thread Starter

    Location:
    Rockford, MI
    General consensus on the Internet about canton is they crave power and would probably do better at 4 ohms...great, another audiophile magic pill to take when I get home!! LoL...love this hobby. We will see if there is any noticeable difference
     
    Dave and jupiterboy like this.
  2. Black Elk

    Black Elk Music Lover

    Location:
    Bay Area, U.S.A.
    The green plot is phase, using the right-hand scale.

    I wouldn't be too concerned about what was written there. Canton has an excellent reputation.

    The comment that the 4...8 ohms applies to the stated frequency response is clearly wrong, as the impedance plot linked to above shows.


    I found this:

    http://www.soundandvision.com/content/canton-gle-speaker-system-measurements

    which measures the model 470, as opposed to 490.

    Note the following:

    GLE 470
    Minimum impedance: 4.1Ω at 210Hz
    Nominal impedance:

    The GLE 470 should be a relatively easy speaker to drive provided that the amplifier is comfortable with a 4Ω load.


    Your larger 490 has a minimum impedance of 3 ohms from 100 - 400 Hz, so is definitely a 4-5 ohm nominal load!
     
    Joey_Corleone likes this.
  3. Joey_Corleone

    Joey_Corleone Forum Resident Thread Starter

    Location:
    Rockford, MI

    Well, that settles it! I will DEFINITELY go to the 4 ohm taps! Glad I asked, and hope to hear audible improvements! Thanks guys, I learned a TON!

    That awkward moment when you realize your speakers could have been performing better for quite some time now.....mmmmmm anxious now to get home....sweet audiophile anxiety lol
     
  4. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    Listen to a bunch of sides. You'll know.
     
    Joey_Corleone likes this.
  5. Joey_Corleone

    Joey_Corleone Forum Resident Thread Starter

    Location:
    Rockford, MI
    Anything that should stand out or listen for?
     
  6. chervokas

    chervokas Senior Member

    Normally you'd listen for changes to the amount of available headroom, bass control, dynamics and frequency balance...but my guess is that with 450 wpc from a solid state amp with autoformers on the output you might not hear much difference between the 4 and 8 ohm taps.
     
    Joey_Corleone and jupiterboy like this.
  7. 62caddy

    62caddy Forum Resident

    Location:
    PA
    It really shouldn't result in much of a change in sonic quality - but no question, the amplifier will be a more stable running those particular speakers from the 4 ohm taps.

    Ron Cornelius of McIntosh would be ideal to consult on this matter - I am unaware if he posts on SH but if the OP would like further insight, I'd suggest posting the question in the McIntosh Forum on AK where there's an excellent chance Ron would respond with a full explanation.

    Glad it all worked out at any rate. Enjoy.

    Thanks.
     
    Joey_Corleone likes this.
  8. ggergm

    ggergm another spring another baseball season

    Location:
    Minnesota
    Does your stereo sound more like real, live, unamplified music? Unamplified music is the only standard and the reason I often use jazz or acoustic rock recordings for evaluation.

    Listen for instruments you know the sound of when they are played without amplification. Piano, acoustic guitar and drums work well for most people, plus the human voice. It is undoubtedly the toughest instrument to reproduce correctly and we all know the sound of people singing. If you know the sound of an orchestra, use classical music for this purpose. People who attend a church which has a real pipe organ will use that.

    After the change, does your stereo sound more real? That's what you want.
     
    Last edited: Apr 15, 2015
  9. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    My experience with a hybrid SS on the bottom/tubes on the top is not going to translate well to your amp. I do always listen to horns though. Horns have a brassy bite, but you don't need any extra grain. If the horns sound immediate and brassy, but have the smoothness then I am happy.
     
  10. Joey_Corleone

    Joey_Corleone Forum Resident Thread Starter

    Location:
    Rockford, MI
    I made the switch. I only played a few sides, but I was awfully tired last night by the time I got to it, so I decided to just go to bed and give it some time. There was definitely a difference in the sound. What exactly, I cannot yet explain because I need more time to adjust. One thing I did notice - I am pretty anal about my equipment. It is not uncommon for me to feel the warmth of the amplifier after a session. Now, with the amount of headroom my amp had, it has never been hot to the touch...I mean my room is only 12x16 and 45wpc is about as loud as it ever needs to be, but after fairly loud sessions, the amp would be at least a little warm. Last night, after going to 4 ohm, it wasn't. Just nice and cool to the touch.

    I suspect this may be because the nominal impedence is closer to 4 ohm like we have been saying here, so in theory (I'm no EE but I think this is right) I think that means the amp was actually having to do less work because the resistance is now not higher than it needs to be.

    In any case, I will see if I can report back after doing some listening. Thanks!
     
    jupiterboy likes this.
  11. Diver110

    Diver110 Forum Resident

    Location:
    Camas
    I'll defer to Chervokas, who I have always found to be a thoughtful voice, on his reading of the graph. I am quite fluent in German and can comfortably read the article. It does not seem to express an opinion on the issue in the text, but it does say the speakers are especially good for Pop-, Rock-, and Jazz fans, for whatever that is worth.
     
  12. The Pinhead

    The Pinhead KING OF BOOM AND SIZZLE IN HELL

    Or black/death metal with double kick-drum and 5-string bass guitar ;)
     
  13. chervokas

    chervokas Senior Member

    ;)
    Still not gonna have much info below 40 Hz. The 5 string in a standard tuning might have its lowest note at 30 Hz so that's low but only if the bass part requires thumping on the open low b string the whole time, and the kick drums, unless they're triggering low samples, which they may be, are gonna be higher than that. It still ain't like a pipe organ or orchestral bass drum.
     
    The Pinhead likes this.
  14. Joey_Corleone

    Joey_Corleone Forum Resident Thread Starter

    Location:
    Rockford, MI
    My first thoughts are less full sounding, but better clarity and more transparent. Not sure which I prefer yet!
     
    Rick58 likes this.
  15. Rick58

    Rick58 Forum Resident

    Location:
    Eagle, ID, USA
    from the curve http://www.audio.de/testbericht/test-standboxen-canton-gle-490-2-1146058.html the impedance is ~3 ohms thru most of the midbass? 100-400Hz, where there's lots of energy in music, I would think. I'd (like someone said above) use the 4 ohm taps and not look back ...

    really, the 452 should drive these using any tap to probably more than jet-engine levels ... so maybe try all 3 and see which you like best? I seriously doubt you can hurt the amp.
     
  16. Rick58

    Rick58 Forum Resident

    Location:
    Eagle, ID, USA
    Huh, I wonder if the lower impedance tap provides lower output impedance as well, which would translate to higher damping factor (at least with a traditional (tube) amp with various transformer taps).

    Of course, the 452 has 'autoformers' which ... I don't remember how they work, exactly ... but think the amp itself is designed to run into 2 ohms, and the autoformers allow it to produce full voltage/power into the higher impedance loads (UNLIKE most SS amps without autoformers) which only produce half the power into 2x the design impedance ...

    The 'less full sounding' may actually indicate less distortion in the bass (and less distortion all over = better clarity and transparency).
     
    Agitater likes this.
  17. Joey_Corleone

    Joey_Corleone Forum Resident Thread Starter

    Location:
    Rockford, MI
    I read somewhere else that 4 ohms vs 8 ohms on this amp will yield about -3dB of volume so maybe that is part of it.

    I did a lot of research yesterday and today and have found nothing that supports running these Cantons (or any Cantons showing 4..8 in the spec) at 8 Ohms would be better. Plenty supporting 4 Ohms and saying how they love power.

    I would probably stick at 4 just based on the fact that it seems to be, at least on paper the right thing to do, but will continue on for at least a week before making a final decision.
     
    62caddy likes this.
  18. head_unit

    head_unit Senior Member

    Location:
    Los Angeles CA USA
    That is a matter of debate. Famed acoustic guy Matti Ottala gave a paper to the Audio Engineering Society wherein he stated that some "8 ohm" speakers could momentarily try to draw as much current as a 1 ohm resistor to the amplifier. I'm oversimplifying, but it was something like that. This led to the whole "high current" craze, particularly from Harman Kardon (whose receivers nevertheless had a paltry 80 dB S/N on their CD inputs…um, anyway…). However, Ottala's work was based on digital simulations of the speaker impedance of some popular models. Later authors claimed amplifiers never draw more current than the D.C. resistance of the voice coil. And I never seem to find the time to do some definitive testing and write my own paper about it :(. Meanwhile another angle is that even if the instantaneous impedance is not so low, the phase angle (meaning the load looks kinda like a capacitor or coil) could drive the amplifier into protection or distortion, so big current may still be useful even if Ottala was incorrect.

    Anyway, there are two aspects to the impedance taps on tube amps. One is how much the transformers literally transform the voltage and current. A 4 ohm tap would have less maximum voltage but ideally more maximum electric current than an 8 ohm tap, assuming the amp was not clipping. So something like the Canton with a 3 ohm minimum should be "safer" (for the amplifier) if connected to the 4 ohm tap.

    Actually the "safest" connection is called "if it starts to sound bad, TURN IT DOWN" and you should never damage your speakers or amp.

    The second aspect is how the tube amplifier and speaker interact. Solid state amps usually have a very low impedance-excepting most class D amps at high frequencies-and the voltage from the amp pretty much all goes to the speaker and does not vary much with frequency. Tube amps typically have a much higher output impedance, and the voltage from the amp itself gets divided between the amp and the speaker. This varies with the amp, the impedance tap on the amp, and the impedance curve (both static and instantaneous) of the speaker. So the response of the amplifier at the actual speaker terminals is not flat at all.

    In summary, "if it starts to sound bad, TURN IT DOWN" and as for the taps, feel safer at 4 ohms or experiment which sounds best to you.
     
    62caddy likes this.
  19. head_unit

    head_unit Senior Member

    Location:
    Los Angeles CA USA
    I *think* it is not that simple due to the impedances in the transformer itself.

    Actually it is a fine point, but solid state amps don't really do that. The marketing specifications may do that, but any amp I ever measured did not actually double the power when the impedance was halved. Typical amps might gain 50-60% more watts. Even a massive and highly expensive Mark Levinson tested back in the day in..Stereophile?…did not double power. It was supposed to be like 100W into 8 ohms and 200 into 4 ohms, but actually produced like 150@8 and 200@4. (Again I'm simplifying a bit; the point is the higher impedances are underrated to make it look like the amp is perfect. This is a very very common practice.)
     
    62caddy likes this.
  20. Joey_Corleone

    Joey_Corleone Forum Resident Thread Starter

    Location:
    Rockford, MI
    So, by changing to 4 ohm, am I kind of sort of actually EQing?
     
  21. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    I had my previous amp for more than 20 years. I would go back to 8 ohm once every few years. I would leave it that way for a week or so before I got tired of it. As above mentioned, less distortion, even if the power seemed somewhat diminished.
     
  22. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    Less about frequency response and more about the ability to control the drivers in a certain frequency. Damping factor of an amp not only moves the magnet but also slows it as the sound decays. An amp that has good grip has the ability to excite and damp motion, which translates to more control—ability to keep individual sounds separated, which can sometimes sound less loud, IMO.
     
  23. Rick58

    Rick58 Forum Resident

    Location:
    Eagle, ID, USA
    IMO, not significantly. Maybe a tiny amount ... If you look at plots in Stereophile for some (more 'standard') tube amps with high output impedance, they have low damping factor (output impedance = a significant % of speaker (load) impedance) - then the frequency response (FR) will change. In most cases I've seen, the 4 ohm tap will have a lower output impedance (less turns) and the FR will vary less than if the 8 ohm tap is used. Of course what jupiterboy said is true also, I believe.

    Hard to say with the autoformers on McIntosh amps ...! probably some folks can tell you, but I suspect that FR changes would be pretty mild ... but may be discernable ... and also other effects may dominate the sonics. As before, I think it's worth trying both/all of the taps, you're unlikely to hurt the amp! But IMHO the 4 ohm tap is the way to go.
     
  24. Joey_Corleone

    Joey_Corleone Forum Resident Thread Starter

    Location:
    Rockford, MI
    Wanted to follow up on this and say my perceptions on volume were actually right! I did some tests tonight and found that when using the 4Ohm taps, the volume is about 3dB quieter than the 8 ohm taps. Here was my test

    I setup an SPL meter on a tripod at the listening position, making sure not to touch it between tests. I then turned on my AV receiver and told it to play a test tone on the left channel. My AV receiver is hooked into the system, utilizing the preamp pass through feature, but I think that is irrelevant to this. Anyways, I turned up the AV receiver until the SPL read 75dB and noted that the AV receiver gain was at -2dB. I then switched to the 8 ohm taps, and I needed only a setting of -5dB on the receiver to achieve the same 75dB SPL reading

    Can anybody help me understand WHY? I would think that with LESS resistance (4ohm) you would have more current and thus more volume at the same volume knob position. I would love to understand why.

    So that clears up that what I thought I was hearing was in fact what I was hearing. I still stand by my original findings. 4 ohm sounds cleaner, more transparent, and more open...more "air" if you will, but at the "cost" of volume at the same preamp volume position. Now that I know the delta is 3dB, I think when I properly level match, I will prefer the 4 ohm even more!
     
    Rick58 likes this.
  25. Rick58

    Rick58 Forum Resident

    Location:
    Eagle, ID, USA
    I can't comprehend/explain what's going on, but note that the load impedance is staying the SAME, it's the output tap that you're changing on the McIntosh amp. The autoformers' operation is beyond my feeble brain at the moment, but the fact that you're changing the tap on the autoformer is likely/certainly the reason. Likely someone who knows autoformers and McIntosh's implementation of them could explain it. I may try later ...

    Certainly glad your results 'matched' with what (IMO) should be the correct tap.
     
Thread Status:
Not open for further replies.

Share This Page

molar-endocrine