Guys,can somebody tell me how many ohms I will end up with ,with 8-8ohm spks wired in parallel, and also how many ohms I will end up with ,with 8-8ohm spks wired in series/parallel. Thanks for any help. Ampeg SVT 8-10 redo!!
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Ohms
- Thread starter glenn joyner
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All in parallel will give you an expensive amp repair.
Series-parallel you have options. Four in series, parallel with another four in series gives you 16 ohms. Four pairs of 2 in series, then the pairs paralleled together gives you 4 ohms.
Series-parallel you have options. Four in series, parallel with another four in series gives you 16 ohms. Four pairs of 2 in series, then the pairs paralleled together gives you 4 ohms.
Hartke LH1000. But you'd have to split it into 2 sections @ 2 OHM each.Eight all in parallel is 1Ω. Not good for any known amplifier.
Yes but that was not what the OP asked was it?
BTW All of my amplifiers are safe into 2Ω loads.
I wasn't sure because I thought the SVT-810 may be already split into 2 sections. The cool thing about the LH1000 is it can power two 2 Ohm Cabs at once in Dual Parallel mode.Yes but that was not what the OP asked was it?
BTW All of my amplifiers are safe into 2Ω loads.
I believe SVT 810s use eight 32 ohm speakers wired in parallel. 32/8 = 4 ohms. If you have a bad driver, I would either have it reconed, or replace a pair with a reasonably compatible pair of 32 ohm speakers.
If you want to replace all with 8 ohm speakers you will need to use a series/parallel or a parallel/series wiring scheme. You need to choose speakers that are compatible with the volume of the cabinet.
If you wire four 8 ohm speakers in a parallel/series configuration or series/parallel configuration you get an 8 ohm load.
Compare series/parallel with parallel/series.
Parallel/Series
Connect two speakers in parallel: 8/2 = 4 ohms. Connect the other two speakers in parallel, so you have two 4 ohm circuits. Connect both sets of parallel speakers in series 4*2 = 8 ohms.
Series/Parallel
Connect two speakers in series: 8*2 = 16 ohms. Connect the other two speakers in series, so you have two 16 ohm circuits. Connect both sets of series speakers in parallel 16/2 = 8 ohms.
Here's another example of series/parallel wiring.
As you can see the wiring gets pretty complicated. Connect two of these 8 ohm circuits in parallel and you are back to the cabinet's original 4 ohm load.
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I saw a Crown (microtech) demo in 1986. The regional sales guy was running each side @1 ohm, full range, cranked. Not recommended-just a demo. It’s spec’d @ 2 ohms.Eight all in parallel is 1Ω. Not good for any known amplifier.
I bought one and ran it hard for years, often 2 ohms on one side for the monitors and 4 ohms on the other side for the 125 hz subs.
I still have the amp, though it gets zero use these days. It worked the last time I fired it up a year ago.
Just a story- but I agree - stick to 2 ohms or whatever the manufacturer specs.
One configuration you might consider for a 4 ohm total load would be to wire 2 speakers in series for a 16 ohm load. Do the same for the other 6 speakers to get four 2-speaker sections. Wire each section as a branch circuit of a parallel network with a total impedance of 4 ohm an a total power handling capability of 8 x single-speaker power.
This would allow you to drive a typical solid-state power amp to it's maximum output. If you're looking at a tube poweramp you might want to go for a higher load impedance, like 8 or 16 ohms maybe.
This would allow you to drive a typical solid-state power amp to it's maximum output. If you're looking at a tube poweramp you might want to go for a higher load impedance, like 8 or 16 ohms maybe.
If you can find an Eden WT800C with the porchlight (backlit logo), that will do it. It has two channels and will go down to 2 ohms on each side. You can connect one or two cabs and daisy chain 2 or 3 cabs on each side. All the connections are parallel so the amp will see the same 2 ohm load on each channel any way you hook it up as long as it's 4 cabs on each side. That will handle 4 cabs on each side. Each side will put out 550-watts rms for a total of 1100 watts. That would be 137.5-watts per cab into 8 cabs. If you drop the cabs to 4 (2 on each side) you'd get 220-watts per cab (440-watts per side @4 ohms).
You can of course get a series switch box or boxes and hook everything up in serial, which will just keep adding ohms load. 4-cabs x 8-ohms =32 ohm load. 8 cabs at 8-ohms- 64 ohm load. Running that high of an ohms load won't hurt any amplifier that I know of. Problems come from running too low of an ohms load. BUT...you aren't going to get many watts out of it. Each time you raise the ohms load, you drop the watts delivered, sometimes by half. Each cab you add in series will take another big chunk of your power away. It's a bit like taking a 2-inch fire hose and dropping it in size down to 1/4"...you'll get very few watts out of the amp. I think you'd soon reach the point where diminishing returns make it totally impractical.
I used to run a Sunn B202 (212) cab with a GK115 powered by a GK250 backline amp. That amp had a minimum ohms load of 8 ohms and was NOT made to run two cabs. But my Sunn cab had both parallel and series outputs, so I hooked the Sunn up to the amp and the GK cab up to the Sunn cab. That put a 12 ohm load on the amp, which was no problem but it dropped the power from 125-watts to about 85-watts or so. However, since I more than doubled the speaker area, I got more than enough sound out of it to compensate for the drop it power. Do that with 8 cabs though and I think you'll find it an exercise in futility
If I recall correctly those early SVT's were supposed to be run with 2 cabs each to get the most out of the amp. Another option you might consider is running two-cabs off of your amp and then slaving 3-more amps to run two cabs each. That would give you crazy amounts of sound. Of course, you'll need a truck and some roadies to move it all, but why not?
My SVT cab is from the 70's and has all 8 spk. wired together ,not 4 at a time like the new ones. Actually I'm trying to get to 4 ohms ,that's what my head is. But I have 8 new 4 ohm eminence neo basslite midbass spks already bought but Eminence said they weren't meant for sealed cabinets,so I bought 8 Eminence SC10 basslite 16 ohm spks that are made for sealed cabinets, But I cant get to 4 ohms with either set of speakers, so I'm wondering if I should just get another head to match whatever ohms I end up with, with what I have! Might be cheaper now ! lol. Do any of you know how I can get to 4 ohms with either set I have??? I do have a Peavey head that is 2 ohms though.
But I have 8 spks. in the SVT and need the whole thing to end up at 4ohms if possible.
Wire the top two drivers in series, positive of one to the negative of the next.. Repeat for each level. You now have four 16Ω sections.
Wire the unused positive of each level together and connect to the input jack tip and/or SpeakOn +1.
Wire the unused negative of each level together and connect to the input jack sleeve and/or SpeakOn -1.
Your cabinet now has a 4Ω total impedance.
Wire the unused positive of each level together and connect to the input jack tip and/or SpeakOn +1.
Wire the unused negative of each level together and connect to the input jack sleeve and/or SpeakOn -1.
Your cabinet now has a 4Ω total impedance.
He traded the 8 ohm drivers for 16 ohm drivers so this configuration will yield 8 ohms. With eight 16 ohm speakers he has to choose between 8 and 2 ohms total load.
A thought: If you are planning to use the cabinet with a tube amp you could also wire the series junction of each level together. In essence this will wire four drivers together in parallel for 2Ω. The other four, also in parallel in series with the first set adds to the required 4Ω. This way if a driver fails oren circuit the other seven will still produce sound.
