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Topic: Loudspeaker 4 or 8 ohms |
Billy Murdoch
From:
Glasgow, Scotland, U.K.
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Posted 14 Nov 2019 1:31 pm |
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Using the Quilter tone block as an example there is a 4ohm outlet and an 8ohm outlet The amp is 200w with either speaker. What is the sonic difference(if any) or advantage of one speaker over the other?
Billy |
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Jack Stoner
From:
Kansas City, MO
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Posted 14 Nov 2019 2:05 pm
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| The impedance of a speaker should make no difference. |
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Ian Rae
From:
Redditch, England
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Posted 14 Nov 2019 2:05 pm
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The amp will deliver 200W if the speaker is connected to the correct socket for its impedance, less if it isn't.
_________________
Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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Billy Murdoch
From:
Glasgow, Scotland, U.K.
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Posted 14 Nov 2019 3:02 pm
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Thanks for replying Gents.
I can understand the amp delivering 200 watts but I had wondered if the final tone remains the same with a correctly attatched 4 or 8ohm speaker,again both speakers would have to be the same design Isuppose.
Best regards
Billy |
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Douglas Schuch
From:
Valencia, Philippines
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Posted 14 Nov 2019 5:45 pm
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With an 8-ohm speaker, you can add another speaker easily - either 8 (ideal) or 4 (should be no problem). I actually just asked Quilter about using 2 x 4 ohm speakers, as that is what I own, and here is Pat Q's reply:
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Our amps are forgiving about impedance loads, and will at least protect themselves if necessary.
Running two 4-ohm loads will cause additional temperature rise but it would only become problematic if you play long and hard at Master settings above 100W. If you hear harsh clipping on “FR†mode, or experience a gentle cutback of power in any mode, the amp is signaling thermal overload. If you encounter these problems at the playing levels you want to use, then yes, you could make a series-type Y-cable and run them in series on the 8-ohm jack. |
I had asked if there would be a problem using a home-made Y cable to run them in series. 2x4 ohm speakers in parallel equals 2 ohms. 2x4 ohm in series equals 8 ohms.
As for tone and volume - I don't know. I never knew until recently that the impedance affects that. I know that Tim with Milkman recently commented that his "The Amp" sounded equally loud with either speaker, even though it rates 50 watts with an 8-ohm speaker, and 100 watts with a 4-ohm. Based on reading various threads here on the forum, volume will be about the same (despite theoretical wattage output differences), but tone will not. But with the Quilter, I would suggest buying one of each? It's set up to run either a 4 or an 8 - and if Pat says it can run two 4-ohm speakers, it will surely run one of each!
edited to substitute "impedence" for "resistance".
_________________
Bringing steel guitar to the bukid of Negros Oriental! |
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George Kimery
From:
Limestone, TN, USA
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Posted 14 Nov 2019 6:19 pm Loudspeaker 4 or 8 ohms
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I had a JBL-D130 8 ohm in one of my Stereo Steel cabinets and an identical 4 ohm in the other cabinet. I could not hear any difference in the sound. The 4 ohm was just a little louder, but not much.
My Evans SE200 came with a stock 8 ohm speaker but it is rated for a 4 ohm. It has an external speaker jack so you can run another 8 ohm speaker. This will give a 4 ohm load between the two. I replaced the speaker with a JBL D-130 4 ohm. So now, I can't use an extension cabinet. |
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Jerry Horch
From:
Alva, Florida, USA
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Posted 16 Nov 2019 4:32 am Amp
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Wondering if anyone has used 4 4ohm jbl's on their walker sterio steel rig...and if it can be done ?
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Franklin D10 /Walker Sterio Steel JBL's /DigiTech Quad4/ Korg Toneworks/ Dobro DM 1000 / Santa Cruz Guitar VA |
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Douglas Schuch
From:
Valencia, Philippines
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Posted 16 Nov 2019 5:44 am
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Jerry, I actually asked GD just a few days ago about doubling up speakers (for different reasons - I have a blown power amp on one channel - hoping to get it fixed, but just in case). Basically, the answer is not so great:
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Combining spkrs. Ugh! The problem is, if you have two 4 ohm spkrs and you just use a Y cord (called parallel), that creates a 2 ohm load and most amps would be sensitive to that. The SS may or may not be depending on how loud you played (so I suggest "no"). Essentially, a 2 ohm loud forces an amp to run much hotter and heat is "baaaaaad".
To run in series would take a very customized cable (I've never conjured up the idea but it would be very tricky). The 1/4" jacks Hot lead goes to the 1st spkr, the 1st spkrs ground to the 2nd spkrs Hot, then the 2nd spkrs ground back to the 14" jacks ground. And the whole time being very careful not to mess things up and accidentally grounding the SS's output. That'd blow things up. Plus, if it was working, the power of the amp drops to about half; somewhere around 150 watts. |
Actually, doing a Y-cable that connects them in series is not unheard of - and Pat Quilter, when asked a similar question about his amp (see my reply above) also discussed the heat concerns, but thought a Y cable that was set up to put them in series would be fine - but then, his amp has an 8-ohm connection. Stereo Steels do not - just the two channels, 4 ohms each.
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Bringing steel guitar to the bukid of Negros Oriental! |
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George Kimery
From:
Limestone, TN, USA
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Posted 16 Nov 2019 7:57 am Loudspeaker 4 or 8 ohm
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| Jerry, 4 ohm JBL's is the norm for Stereo Steel cabinets. That is exactly what I have in mine. Notice there are no extra speaker out jacks in the cabinets to allow you to hook two together. They are designed to operate in stereo mode with separate power amps driving each speaker. |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 16 Nov 2019 10:14 am
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With a tube amplifier, it would make a small difference, even if the impedances were perfectly matched. However, that difference would very likely not be enough to be noticed, except with laboratory equipment.  |
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Jerry Horch
From:
Alva, Florida, USA
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Posted 16 Nov 2019 1:40 pm Cabs
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Plenty of room with the 2 speakers for sure..it will blow you away...dought if I've ever had it above 2 or 3....but just think of richness of a stack on each side...
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Franklin D10 /Walker Sterio Steel JBL's /DigiTech Quad4/ Korg Toneworks/ Dobro DM 1000 / Santa Cruz Guitar VA |
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George Kimery
From:
Limestone, TN, USA
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Posted 16 Nov 2019 2:22 pm Loudspeaker 4 or 8 ohm
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| Jerry, I just re-read your post and noticed you were asking about 4 speaker cabinets. not 2. You could do it as long as all the speakers were 8 ohm and you used 2 separate power amps, each one driving 2 speakers. |
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Godfrey Arthur
From:
3rd Rock
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Posted 16 Nov 2019 3:05 pm
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Not knowing what model you have but the specs seem to be the same.
It will do 4 ohms up to 8 ohms as per Tone Block specs.
The photo below shows the rear panel.
You can see that there is script that shows 8+8 between to the two speaker jacks. A little confusing but it's telling you if you plug in two speakers (one in each jack) each speaker should be 8 ohms to reduce to 4 ohms if you don't have a multi-speaker cabinet set at 4 ohms.
What will the sound be like at 4 ohms?
The speaker will be tighter, clearer, more alive, alert and quick to respond at 4 ohms. But it better be a 4 ohm speaker you're connecting there or a pair of 8 ohms wired to 4 ohms if you want to get that response.
Remember your amp will work fine with an 8 ohm speaker.
You will notice more immediate power out of your amp at 4 ohms without cranking the volume knob too high.
The higher the number impedance (8 ohms) the speaker becomes lackadaisical and will dissipate more of the amp's power. Your volume setting will be higher at 8 ohms to get a similar loudness than if you're plugged into a 4 ohm speaker. And still the overall response won't be the same with 8 ohm as it would with a 4 ohm speaker. It can be subtle so your sensitivity to changes in volume and sound pressure levels is key.
Since the amp was designed for 4 ohms, you'll get 0-60 quicker so to speak using a 4 ohm speaker.
Try it and you'll get the idea. Might be easier to compare the same brand of speaker at the different impedances so as not to get thrown off.
Power Output: 0 to 200 watts, 4-8 ohms
Speaker 1 Output: 8 ohms, 200 W minimum recommended rating
Speaker 2 Output: 4 ohms, 200 W minimum recommended rating
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ShoBud The Pro 1
YES it's my REAL NAME!
Ezekiel 33:7 |
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David Ball
From:
North Carolina High Country
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Posted 16 Nov 2019 4:17 pm
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On hi fi tube amps, I've always preferred 16 ohm speakers. The tubes I like seem to prefer the extra load (given a 16 ohm secondary on the output transformer). With really low powered triode single ended amps that I like, it does make a difference. But I'm talking 1 or 2 watt amps here and really efficient speakers.
When you get up to guitar amp power and solid state amps, I doubt there's any sonic difference. I've never heard it.
Dave |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 17 Nov 2019 7:09 am
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| David Ball wrote: |
| On hi fi tube amps, I've always preferred 16 ohm speakers. The tubes I like seem to prefer the extra load (given a 16 ohm secondary on the output transformer). |
The "load" is probably less with the higher impedance. The significant difference is the back EMF generated by the speaker and how it affects the damping. I think you're right about the sound change in hi-fi applications, and that's probably why almost all the old hi-fi amps had a 16-ohm capable output transformer. |
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