SPEAKER WIRING

***Guv'nor*** · 11-02-2006, 09:41 AM

The most common methods to wire up speakers are Series and Parallel.

It is also quite common to wire Speakers in a Series/Parallel Combination.

Single speaker

Wiring up Speakers correctly to provide the best possible sound, requires some knowledge of Loading, Phase, and Impedance, while understanding Ohms Law will help you to connect your speakers properly.

SERIES

Adding Speakers in series increases the overall resistance of the circuit.

Therefore the resistance of each Speaker is added together, For advanced installations with Multiple Speakers, Series Speaker wiring can be used to increase the resistance of the “equivalent” or “overall” resistance that the Amplifier sees. This allows the Amplifier to run cooler and more efficiently.

Series Circuits are “voltage dividers”, and using Ohms Law, one sees the result as a decrease in amplified voltage audio signal to each Speaker. Since Series Circuits are “voltage dividers” each Speaker sees a percentage of the amplified output from the Amplifier. It is often assumed the Amplifier is producing less output, but it still produces the same output, because each Speaker only gets a percentage of the overall power.

Formula: Znet = Z1 + Z2 + Z3 + .... + Zn

Example:

2 x 4 Ohm Speaker = 4 + 4 = 8 Ohm Load
2 x 8 Ohm Speaker = 8 + 8 = 16 Ohm Load

PARALLEL

Adding Speakers in parallel decreases the overall resistance of the circuit

Parallel Speaker Wiring combines all Speakers (+) positive Speaker leads together, and all (-) negative Speaker leads together.

Adding additional Speakers is as easy, however, adding Speakers in Parallel causes the overall resistance of the circuit to drop, as resistance drops, the current must increase according to Ohms Law. So, each time a Speaker with the same resistance is added to the parallel circuit, the current draw on the amp increases. The circuitry of the amp must be able to handle this increase in current at the reduced resistance.

Formula: Znet = 1 / (1/Z1 + 1/Z2 + ... + 1/Zn)

Example:

2 X 4 Ohm Speaker = 1 / (1/4 + 1/4 ) = 2 Ohm Load
2 x 8 Ohm Speaker = 1 / (1/8 + 1/8 ) = 4 Ohm Load

Note: If more than 2 Speakers are connected in Parallel, so long as they are all the same impedance then the net impedance of the load is equal to the impedance of the one Speaker divided by the total number of Speakers. For Example 3 8 Ohm Speakers in Parallel, the Impedance is 8/3 or 2.667 Ohms.

A COMBINATION OF SERIES & PARALLEL

In reality this is just two sets of Series Speakers wired in Parallel

Formula: Znet = Znet1 + Znet2 + ... + Znetn; where Zneti = 1 / (1/Z1 + 1/Z2 + ... + 1/Zn)

Example:

4 X 8 Ohm Speaker = [1 / (1/8 + 1/8 )] + [1 / (1/8 + 1/8 )] = 4 + 4 = 8 Ohm Load

WIRING A FULL STACK

The amp usually has two speaker outputs (one for each cab)

The output jacks are wired in parallel. It means Znet = 1 / (1/Z1 + 1/Z2 + ... + 1/Zn)

Therefore having 2 cabs at 8Ohm the head will see 1 / (1/8 + 1/8 ) = 4 Ohm Load

Enjoy!

superleadfixer · 11-02-2006, 06:37 PM

Also the serie/parallel combination in a 4x12 cab will have a draker sound and a little harcher, if your amp (set up) is too dark one way to help this out would do a Parallel/series connection instead, that will give a little bit cleaner and brighter sound......... :wink:

surfdog777 · 11-05-2006, 11:40 AM

Correct me if this is wrong, I'm running both cabs in a full stack 16ohm mono, the head is set at 8 ohms....this is the correct setting, eh?

***Guv'nor*** · 11-05-2006, 03:57 PM

1 / (1/16 + 1/16 ) = 1 / (0.0625 + 0.0625) = 1/0.125 = 8 Ohm Load

You're ok.

Jimib · 04-09-2008, 05:33 AM

I am looking at buying a cab that has 2 16ohm speakers in it, am i correct in saying my amp should be set at 8 ohms?

Thanks

Pearse · 06-12-2008, 09:55 AM

I have a 1960A cab and looks like the speakers were refitted. there are 4 15 ohm speakers its not wired the same way as celestion would have said to wire it in their series diagram, its simpler like one speaker connected to another speaker and the two end wires are conected to the terminals. What do i choose, or do. It still works fine on the 16 omh output.

KingKong · 08-18-2008, 08:20 PM

Howdi all,

I just signed up on the forums and am in need of assistance!

I just bought a nearly new tsl 100 head, and I want to make sure my cabinet is wired for 16 ohm impedance. I'm attaching a pic. The lower terminal of the upper right speaker (as you look at the pic) is positive. I believe the top speaker terminals on the speakers on the left are positive (marked with red dot). The speakers are each 16 ohm. I believe the top two are wired together in series, the bottom two are wired together in series, and the upper pair is wired to the lower pair in parallel.

If anyone could take a look at this and share an opinion I'd appreciate it!

I'm thinking it's 16 ohms total impedance, but I'd like another opinion before I use the 16 ohm output from the tsl 100.

Thanks!
Kong

Adwex · 08-18-2008, 10:00 PM

Quote:

Originally Posted by KingKong

Howdi all,

I just signed up on the forums and am in need of assistance!

I just bought a nearly new tsl 100 head, and I want to make sure my cabinet is wired for 16 ohm impedance. I'm attaching a pic. The lower terminal of the upper right speaker (as you look at the pic) is positive. I believe the top speaker terminals on the speakers on the left are positive (marked with red dot). The speakers are each 16 ohm. I believe the top two are wired together in series, the bottom two are wired together in series, and the upper pair is wired to the lower pair in parallel.

If anyone could take a look at this and share an opinion I'd appreciate it!

I'm thinking it's 16 ohms total impedance, but I'd like another opinion before I use the 16 ohm output from the tsl 100.

Thanks!
Kong

Welcome, Kong.

It's tough to see in the pic exactly how the bottom pair is wired, but the way you describe everything is correct: top pair in series + to -, bottom pair in series + to -, with the two pairs wired together in parallel + to +, and - to -. Wired this way, if all the speakers are the same impedance individually, the total impedance of the 4 will be the same as the impedance of one, so use the 16 ohm output on the TSL.

Interesting mix of speakers. I recognize the V30, but what are the others?

Can you take a better pic detailing the wiring on the bottom pair? ...and exactly which terminals are used to connect the top and bottom pairs in parallel?

Adam

KingKong · 08-19-2008, 12:15 AM

Quote:

Originally Posted by Adwex

Welcome, Kong.

It's tough to see in the pic exactly how the bottom pair is wired, but the way you describe everything is correct: top pair in series + to -, bottom pair in series + to -, with the two pairs wired together in parallel + to +, and - to -. Wired this way, if all the speakers are the same impedance individually, the total impedance of the 4 will be the same as the impedance of one, so use the 16 ohm output on the TSL.

Interesting mix of speakers. I recognize the V30, but what are the others?

Can you take a better pic detailing the wiring on the bottom pair? ...and exactly which terminals are used to connect the top and bottom pairs in parallel?

Adam

Thanks for the response and the welcome Adam.

I bought this cabinet in about 1990, used and battered. One of the speakers was blown, and I replaced it with the V30. After a phone call to Marshall and some checking on the internet I dated the cabinet to the late 70's and was told it was a bass cabinet.

It's pretty late here and I'm headed to bed, but tomorrow I'll open it up again and post some more detailed pictures of the wiring and speakers.

Thanks again!

-Kong

KingKong · 08-20-2008, 05:52 PM

Quote:

Originally Posted by Adwex

Welcome, Kong.

It's tough to see in the pic exactly how the bottom pair is wired, but the way you describe everything is correct: top pair in series + to -, bottom pair in series + to -, with the two pairs wired together in parallel + to +, and - to -. Wired this way, if all the speakers are the same impedance individually, the total impedance of the 4 will be the same as the impedance of one, so use the 16 ohm output on the TSL.

Interesting mix of speakers. I recognize the V30, but what are the others?

Can you take a better pic detailing the wiring on the bottom pair? ...and exactly which terminals are used to connect the top and bottom pairs in parallel?

Adam

OK, I took some more pics and here they are...

The lower 2 are original G12H 30 Watts. Above are a G12C-30 and a G12 Vintage 30.

I have no idea where these speakers rank in quality, I just know the thing sounds great. I'd love to hear anyone's assessment of this setup and if there's any reason these speakers should not be mixed!

Adwex · 08-20-2008, 06:19 PM

Quote:

Originally Posted by KingKong

OK, I took some more pics and here they are...

The lower 2 are original G12H 30 Watts. Above are a G12C-30 and a G12 Vintage 30.

I have no idea where these speakers rank in quality, I just know the thing sounds great. I'd love to hear anyone's assessment of this setup and if there's any reason these speakers should not be mixed!

Well the wiring looks correct. As far as ranking, I'd say those G12H's on the bottom rank pretty high on the quality scale. I have one new G12H Heritage, and it's a killer speaker (expensive too). The V30 is a V30...good, but not quite a G12H. I know nothing about the G12C, but from the looks of the small magnet, I'd guess that it's the weak link in your chain. I don't know, maybe it adds something the others don't have.

Good heavy gauge speaker wire too.

Post a sound clip if you can.

11-02-2006, 09:41 AM	#1 (permalink)
*Guv'nor* Moderator Join Date: Aug 2006 Posts: 243	SPEAKER WIRING The most common methods to wire up speakers are Series and Parallel. It is also quite common to wire Speakers in a Series/Parallel Combination. Single speaker Wiring up Speakers correctly to provide the best possible sound, requires some knowledge of Loading, Phase, and Impedance, while understanding Ohms Law will help you to connect your speakers properly. SERIES Adding Speakers in series increases the overall resistance of the circuit. Therefore the resistance of each Speaker is added together, For advanced installations with Multiple Speakers, Series Speaker wiring can be used to increase the resistance of the “equivalent” or “overall” resistance that the Amplifier sees. This allows the Amplifier to run cooler and more efficiently. Series Circuits are “voltage dividers”, and using Ohms Law, one sees the result as a decrease in amplified voltage audio signal to each Speaker. Since Series Circuits are “voltage dividers” each Speaker sees a percentage of the amplified output from the Amplifier. It is often assumed the Amplifier is producing less output, but it still produces the same output, because each Speaker only gets a percentage of the overall power. Formula: Znet = Z1 + Z2 + Z3 + .... + Zn Example: 2 x 4 Ohm Speaker = 4 + 4 = 8 Ohm Load 2 x 8 Ohm Speaker = 8 + 8 = 16 Ohm Load PARALLEL Adding Speakers in parallel decreases the overall resistance of the circuit Parallel Speaker Wiring combines all Speakers (+) positive Speaker leads together, and all (-) negative Speaker leads together. Adding additional Speakers is as easy, however, adding Speakers in Parallel causes the overall resistance of the circuit to drop, as resistance drops, the current must increase according to Ohms Law. So, each time a Speaker with the same resistance is added to the parallel circuit, the current draw on the amp increases. The circuitry of the amp must be able to handle this increase in current at the reduced resistance. Formula: Znet = 1 / (1/Z1 + 1/Z2 + ... + 1/Zn) Example: 2 X 4 Ohm Speaker = 1 / (1/4 + 1/4 ) = 2 Ohm Load 2 x 8 Ohm Speaker = 1 / (1/8 + 1/8 ) = 4 Ohm Load Note: If more than 2 Speakers are connected in Parallel, so long as they are all the same impedance then the net impedance of the load is equal to the impedance of the one Speaker divided by the total number of Speakers. For Example 3 8 Ohm Speakers in Parallel, the Impedance is 8/3 or 2.667 Ohms. A COMBINATION OF SERIES & PARALLEL In reality this is just two sets of Series Speakers wired in Parallel Formula: Znet = Znet1 + Znet2 + ... + Znetn; where Zneti = 1 / (1/Z1 + 1/Z2 + ... + 1/Zn) Example: 4 X 8 Ohm Speaker = [1 / (1/8 + 1/8 )] + [1 / (1/8 + 1/8 )] = 4 + 4 = 8 Ohm Load WIRING A FULL STACK The amp usually has two speaker outputs (one for each cab) The output jacks are wired in parallel. It means Znet = 1 / (1/Z1 + 1/Z2 + ... + 1/Zn) Therefore having 2 cabs at 8Ohm the head will see 1 / (1/8 + 1/8 ) = 4 Ohm Load Enjoy!

11-02-2006, 06:37 PM	#2 (permalink)
superleadfixer Senior Member Join Date: Sep 2006 Location: CANADA Posts: 99	Also the serie/parallel combination in a 4x12 cab will have a draker sound and a little harcher, if your amp (set up) is too dark one way to help this out would do a Parallel/series connection instead, that will give a little bit cleaner and brighter sound......... :wink: __________________ I\'ll mod your SLP (or anyother...) Marshall to REAL plexi specifications/with real replica trannies/etc... http://myspace-332.vo.llnwd.net/0145...52020332_l.jpg

04-09-2008, 05:33 AM	#5 (permalink)
Jimib Junior Member Join Date: Nov 2007 Location: United Kingdom Posts: 20	Re: SPEAKER WIRING I am looking at buying a cab that has 2 16ohm speakers in it, am i correct in saying my amp should be set at 8 ohms? Thanks __________________ JTM 45 RI 1960 AHW

06-12-2008, 09:55 AM	#6 (permalink)
Pearse Junior Member Join Date: Jun 2008 Location: Ireland Posts: 29	Re: SPEAKER WIRING I have a 1960A cab and looks like the speakers were refitted. there are 4 15 ohm speakers its not wired the same way as celestion would have said to wire it in their series diagram, its simpler like one speaker connected to another speaker and the two end wires are conected to the terminals. What do i choose, or do. It still works fine on the 16 omh output.

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11-05-2006, 11:40 AM	#3 (permalink)
surfdog777 Junior Member Join Date: Oct 2006 Posts: 15	Correct me if this is wrong, I'm running both cabs in a full stack 16ohm mono, the head is set at 8 ohms....this is the correct setting, eh?

11-05-2006, 03:57 PM	#4 (permalink)
*Guv'nor* Moderator Join Date: Aug 2006 Posts: 243	1 / (1/16 + 1/16 ) = 1 / (0.0625 + 0.0625) = 1/0.125 = 8 Ohm Load You're ok.