Guitar Forums

Go Back   Guitar Forums > The Gear > Technical Info

Reply
 
Thread Tools Display Modes
Old 03-28-2017, 01:11 PM   #1
littlebadboy
Senior Member
 
littlebadboy's Avatar
 
Join Date: Aug 2013
Location: Midwest, USA
Posts: 3,244
littlebadboy The Oven's On But Nothing's Cooking littlebadboy The Oven's On But Nothing's Cooking littlebadboy The Oven's On But Nothing's Cooking
Default What is the difference between series and parallel speakers?

Hello everyone!

I have a PA and pair of speakers in my rec room. Currently, I only plugged one of the 2 speakers. It gives me an option to whether I want it series or parallel.

What is the difference and pros and cons of each setup?

Thanks!
__________________
Squire CV50 BSB, Laguna LE300avb, Yamaha EG 112C2 The Guitar Bass Project, Ovation CS28
Boss GT-1 (demo), TC Ditto X4, Peavey Bandit 112 (red stripe US),
littlebadboy (personal projects) Carol Affection (90's band)
littlebadboy is offline   Reply With Quote
Old 03-28-2017, 02:02 PM   #2
LaPanthere
Senior Member
 
LaPanthere's Avatar
 
Join Date: Mar 2017
Location: Southern France
Posts: 184
LaPanthere Just getting started
Default

Hey

I found this answer on the Seymour Duncan Forum:

"Q: I have two 8 Ohm speakers that I can wire either parallel or series to my tube amp for an impedance of either 4 or 16 Ohm. My amp has both 4 and 16 Ohm output taps. Are there any sonic differences or benefits of series over parallel wiring or vice versa?

A: Connecting two speakers in parallel is an old trick to smooth out speaker response and enhance the damping of either speaker. HIFI designers took it one step further by connecting two speakers of different sizes in parallel. A speaker has a large impedance increase at its fundamental resonance, and depending on the installation, this can cause the speaker to sound boomy or out of control. By connecting two speakers in parallel, particularly two speakers of different sizes with different resonant frequencies, each speaker will tend to quench or dampen the boominess of the other. Since no two speakers are exactly alike, even two of the same size, that damping will occur, however slight, for any speakers connected in parallel. For speakers connected in series, there appears to be less control, and more of what is called 'back EMF' from the speakers fed back into the output circuit. While that seems rather chaotic, many players prefer the series connection, as it gives them a more textured tone, enhanced breakup, and overall a more desireable tone for guitar work. It's totally subjective, of course, and many factors affect the end result, such as voice coil size, gap energy, closed back/open back, output circuit damping, etc. The best thing to do, in my opinion, is try both arrangements since you have the luxury of impedance tap selection, and go with the configuration you like the best."
__________________
Live your dreams, don't dream your life!
LaPanthere is offline   Reply With Quote
Old 03-28-2017, 02:20 PM   #3
St.Fill
To love 'er is tequila...
 
St.Fill's Avatar
 
Join Date: Apr 2012
Location: Fla & Cali
Posts: 4,037
St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms
Default

Quote:
Originally Posted by littlebadboy View Post
Hello everyone!

I have a PA and pair of speakers in my rec room. Currently, I only plugged one of the 2 speakers. It gives me an option to whether I want it series or parallel.

What is the difference and pros and cons of each setup?

Thanks!
If you're only using one speaker, there is no such thing as wiring it in series or parallel... a speaker can only be wired in series or parallel with another speaker or speakers.

Very simply, two speakers with the same ohm rating wired in series will result in a total ohm rating double the ohm resistance of one of the speakers.
Ex: two 8 ohm speakers wired in series will have a 16 ohm resistance total.

That same scenario wired in parallel will result in a total ohm rating of HALF of one of the speakers.
Ex: two 8 ohm speakers wired in parallel will have a 4 ohm resistance total.

With a PA amp (which usually DOES NOT have an ohm selector switch for the amps output):
If you increase the resistance load of the speaker, the PA's overall volume will be lower.
If you decrease the resistance load of the speaker, the PA's overall volume will be louder.
(Meaning an 4 ohm speaker will allow the amp to produce a higher output than an 8 ohm speaker will).

Its not just as cut and dry as that though... some amplifiers REQUIRE a certain ohm resistance from the speaker, and thats much more important when dealing with a guitar amp, especially a tube guitar amp, which is why a guitar amp typically has a selector switch to match the output of the amp relative to the ohm resistance of the speaker.

With a guitar amp, its generally thought to be 'better' to use the highest ohm rating on the amps selector switch, and have a matching speaker for that setting... an amp with a 4, 8 & 16 ohm selector switch should (if possible) be set to 16 ohms and use a 16 ohm speaker cab. That uses the entire winding of the output transformer, as opposed to a portion of the transformers windings.

Effectively, using the 8 or 4 ohm setting on that switch is "tapping" the transformer, and not using the ENTIRE transformer, which can result in a looser, flabby-er sound, especially at higher volumes. Setting it at less than its max setting is like having a smaller output transformer, which is not advantageous.

For a PA amp, I'd use whatever the mfg recommends. If the amp DOESNT have an ohm selector switch, and they say you can use either a 4 or 8 ohm load, I'd use a 4 ohm total load, simply to get the most volume out of the PA. If the amp can tolerate a 4 ohm load, that would provide the least resistance to the amps output, and therefore produce more volume.
__________________
My wife told me "nothing would make me happier than getting a diamond necklace from you".

So I got her nothing.
St.Fill is offline   Reply With Quote
Old 03-28-2017, 02:44 PM   #4
BallisticSquid
Senior Member
 
BallisticSquid's Avatar
 
Join Date: Jul 2014
Posts: 9,115
BallisticSquid feels up puppies BallisticSquid feels up puppies BallisticSquid feels up puppies BallisticSquid feels up puppies BallisticSquid feels up puppies BallisticSquid feels up puppies BallisticSquid feels up puppies BallisticSquid feels up puppies
Default

Quote:
Originally Posted by FillmoreNYC View Post
If you're only using one speaker, there is no such thing as wiring it in series or parallel... a speaker can only be wired in series or parallel with another speaker or speakers.

Very simply, two speakers with the same ohm rating wired in series will result in a total ohm rating double the ohm resistance of one of the speakers.
Ex: two 8 ohm speakers wired in series will have a 16 ohm resistance total.

That same scenario wired in parallel will result in a total ohm rating of HALF of one of the speakers.
Ex: two 8 ohm speakers wired in parallel will have a 4 ohm resistance total.

With a PA amp (which usually DOES NOT have an ohm selector switch for the amps output):
If you increase the resistance load of the speaker, the PA's overall volume will be lower.
If you decrease the resistance load of the speaker, the PA's overall volume will be louder.
(Meaning an 4 ohm speaker will allow the amp to produce a higher output than an 8 ohm speaker will).

Its not just as cut and dry as that though... some amplifiers REQUIRE a certain ohm resistance from the speaker, and thats much more important when dealing with a guitar amp, especially a tube guitar amp, which is why a guitar amp typically has a selector switch to match the output of the amp relative to the ohm resistance of the speaker.

With a guitar amp, its generally thought to be 'better' to use the highest ohm rating on the amps selector switch, and have a matching speaker for that setting... an amp with a 4, 8 & 16 ohm selector switch should (if possible) be set to 16 ohms and use a 16 ohm speaker cab. That uses the entire winding of the output transformer, as opposed to a portion of the transformers windings.

Effectively, using the 8 or 4 ohm setting on that switch is "tapping" the transformer, and not using the ENTIRE transformer, which can result in a looser, flabby-er sound, especially at higher volumes. Setting it at less than its max setting is like having a smaller output transformer, which is not advantageous.

For a PA amp, I'd use whatever the mfg recommends. If the amp DOESNT have an ohm selector switch, and they say you can use either a 4 or 8 ohm load, I'd use a 4 ohm total load, simply to get the most volume out of the PA. If the amp can tolerate a 4 ohm load, that would provide the least resistance to the amps output, and therefore produce more volume.
Isn't the optimal setup to match the impedance of the speaker with the impedance specified on the amp? By doing that, you maximize the power transfer...at least theoretically. I know this is very important with radio transmitters and the transmit antenna.
BallisticSquid is offline   Reply With Quote
Old 03-28-2017, 02:59 PM   #5
Mervin j Minky
Senior Member
 
Join Date: Mar 2015
Posts: 274
Mervin j Minky Just getting started
Default

What is the PA amp brand?

I'm thinking it's more to do with bridging. Whether the output amps are paralleled to increase power into load, non floating, or series, driving the load between the amps, or floating.
(assuming a 2 channel amp and not a mono.)

I don't think I have ever seen the option of series/parallel for 2 speaker loads plugged into the same channel. More than one output from one channel is only parallel as far as I have seen. You have to work out the loads total impedance plugged in.

There are so many output configs nowadays, allowing different combinations of the amps to drive the speaker load.

Last edited by Mervin j Minky; 03-28-2017 at 03:04 PM.
Mervin j Minky is offline   Reply With Quote
Old 03-28-2017, 03:02 PM   #6
St.Fill
To love 'er is tequila...
 
St.Fill's Avatar
 
Join Date: Apr 2012
Location: Fla & Cali
Posts: 4,037
St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms St.Fill is the poster child for Trojan condoms
Default

Quote:
Originally Posted by BallisticSquid View Post
Isn't the optimal setup to match the impedance of the speaker with the impedance specified on the amp? By doing that, you maximize the power transfer...at least theoretically. I know this is very important with radio transmitters and the transmit antenna.
Yeah, for a PA amplifier, thats what I meant when I said:
Quote:
Originally Posted by FillmoreNYC View Post
For a PA amp, I'd use whatever the mfg recommends. If the amp DOESNT have an ohm selector switch, and they say you can use either a 4 or 8 ohm load, I'd use a 4 ohm total load, simply to get the most volume out of the PA. If the amp can tolerate a 4 ohm load, that would provide the least resistance to the amps output, and therefore produce more volume.
Maybe I should have added "If the amp specifically states "Use "THIS" ohm speaker only", then of course, thats what you've gotta use.


On a guitar amp, I always try to use the max setting on the speaker selector switch, simply because of what I said earlier in the post:
Quote:
Originally Posted by FillmoreNYC View Post
With a guitar amp, its generally thought to be 'better' to use the highest ohm rating on the amps selector switch, and have a matching speaker for that setting... an amp with a 4, 8 & 16 ohm selector switch should (if possible) be set to 16 ohms and use a 16 ohm speaker cab. That uses the entire winding of the output transformer, as opposed to a portion of the transformers windings.

Effectively, using the 8 or 4 ohm setting on that switch is "tapping" the transformer, and not using the ENTIRE transformer, which can result in a looser, flabby-er sound, especially at higher volumes. Setting it at less than its max setting is like having a smaller output transformer, which is not advantageous.
__________________
My wife told me "nothing would make me happier than getting a diamond necklace from you".

So I got her nothing.
St.Fill is offline   Reply With Quote
Old 03-28-2017, 03:18 PM   #7
Mervin j Minky
Senior Member
 
Join Date: Mar 2015
Posts: 274
Mervin j Minky Just getting started
Default

Second thoughts.

Are you saying the series /parallel switch is on the speaker box?
Mervin j Minky is offline   Reply With Quote
Old 03-28-2017, 04:10 PM   #8
littlebadboy
Senior Member
 
littlebadboy's Avatar
 
Join Date: Aug 2013
Location: Midwest, USA
Posts: 3,244
littlebadboy The Oven's On But Nothing's Cooking littlebadboy The Oven's On But Nothing's Cooking littlebadboy The Oven's On But Nothing's Cooking
Default

I have a very old SoundCraft Quick Mix 6. I'll check the manual what it has to say... if I find one...



Tried to google... I couldn't find much info about it nor can find a manual.
__________________
Squire CV50 BSB, Laguna LE300avb, Yamaha EG 112C2 The Guitar Bass Project, Ovation CS28
Boss GT-1 (demo), TC Ditto X4, Peavey Bandit 112 (red stripe US),
littlebadboy (personal projects) Carol Affection (90's band)
littlebadboy is offline   Reply With Quote
Old 03-28-2017, 04:50 PM   #9
Mervin j Minky
Senior Member
 
Join Date: Mar 2015
Posts: 274
Mervin j Minky Just getting started
Default

That's a single channel or mono out amp. There is no pre-amp panning, so everything is mono in mono out.

Not what I thought, I was thinking a 2 channel amp.

The ones I Googled just showed twin outputs with "parallel" written across them.
This just means anything plugged into both outputs is joined in parallel.
Plugging one speaker into either output is fine so long as not less than 4 ohms. This is not series.
Plugging 2 cabs into both outputs is fine also. But now each cab can't be less than 8 ohms.
Two 8 ohm cabs in parallel = 4 ohms.

Be mindful of power rating for speakers vs amp output.
Mervin j Minky is offline   Reply With Quote
Old 03-28-2017, 08:57 PM   #10
littlebadboy
Senior Member
 
littlebadboy's Avatar
 
Join Date: Aug 2013
Location: Midwest, USA
Posts: 3,244
littlebadboy The Oven's On But Nothing's Cooking littlebadboy The Oven's On But Nothing's Cooking littlebadboy The Oven's On But Nothing's Cooking
Default

This is my PA system:



The speakers has "in" and "out" sockets in the back. I'm not sure if it is a parallel or series tap. Is there such a thing?

Thank you everyone for all your advice! Thank you Fill!
__________________
Squire CV50 BSB, Laguna LE300avb, Yamaha EG 112C2 The Guitar Bass Project, Ovation CS28
Boss GT-1 (demo), TC Ditto X4, Peavey Bandit 112 (red stripe US),
littlebadboy (personal projects) Carol Affection (90's band)
littlebadboy is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 12:34 AM.


Powered by vBulletin® Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Guitar Competition | Piano Lessons