Wiring four 8ohm Speakers together to achieve 8ohm load?

[ZeosPantera]

I know it is possible. I started a thread here a long while ago where parallel and series were explained in detail.

I'm basically asking if there is a preferred wiring schematic for this.. It is just an experiment right now with some single 6.5" 40watt bookshelves but I want to get it right and not throw a 1 ohm load to anything.

This is the best I can think of.

As I said this is only for an experiment and any help is appreciated.

 

[96cobra10101]

It looks like your doubling it, then dividing it in half, or are you dividing it, and then doubling it?
Either way, seems to be 8 ohm.

 

[ZeosPantera]

It looks like your doubling it, then dividing it in half, or are you dividing it, and then doubling it?
Either way, seems to be 8 ohm.

That's what I figured.. No matter how you cut the cake as long as there is a parallel and series it should be 8ohm.

I know huge clubs hook up massive speaker towers to the sides of the stage with 16 speakers a piece. I assume they do something similar to this. http://blog.mixonline.com/briefingroom/wp-content/uploads/2008/07/versarray-212-flown.jpg

 

[ZeosPantera]

Well I did a temporary patch hookup and my god was there a volume increase. I was using a 50wpc Niles TVA50 to power the 4xDaytonB652's and I only let is go for a minute or so since I want to put the other unit together and have the amp run it in stereo on that amp safely before trying it on the Spec-2.

"I think I'm gonna need a bigger room.."

 

[ZeosPantera]

"I think I'm gonna need a bigger room.."

I still need to play with orientation and decide stack horizontally or vertically. Will spacing them slightly help the boxes resonate. etc etc.

 

[j_garcia]

The impedance may end up being 8 Ohm, but it is still a significant load to the amp. The draw of each speaker also needs to be factored in, because you are still going to clip much sooner with that kind of load.

 

[ZeosPantera]

The impedance may end up being 8 Ohm, but it is still a significant load to the amp. The draw of each speaker also needs to be factored in, because you are still going to clip much sooner with that kind of load.

I am aware of that which is why I am slowly working my way up the amplification ladder.

I started with a tiny little T-amp @ 15wpc and today hooked to a Niles TVA50 50wpc with no clipping but I don't think either setup has the juice to run four 6.5" drivers properly. Another day or two and I will see what the spec-2 makes of it. Then I want to play with speaker orientation and isolation to see what works best.

 

[avnetguy]

The impedance may end up being 8 Ohm, but it is still a significant load to the amp. The draw of each speaker also needs to be factored in, because you are still going to clip much sooner with that kind of load.

If the impedance appears the same to the amp then the load would be identical wouldn't it?

Steve

 

[jonnythan]

If the impedance appears the same to the amp then the load would be identical wouldn't it?

Steve

The load would be identical but each speaker is only getting half the amps (and 1/4 the power) of a single speaker at the same load.

I'm not sure how adding speakers leads to more dB, mathematically, so I don't know if 4 speakers at 1 watt is the same SPL as 1 speaker at 4 watts.

 

[j_garcia]

I think it works like this: if you had 2 speakers playing the same thing on separate channels it would be +6dB. With both of them on the same channel (with impedance matching or something, let's just assume it is the same impedance so the same load to the amp) it would be +3dB because the power to each speaker is now halved. So you get an increase in SPL, but still lose output over separate channels.

 

[highfigh]

Look at what's in each speaker- a woofer, tweeter and crossover. You can't wire two speaker systems in series and have the same response/results. It would be better to add terminals to separate the woofer and tweeter in each cabinet and then work with different wiring configurations, but only if the woofers don't have an inductor.

 

[highfigh]

I still need to play with orientation and decide stack horizontally or vertically. Will spacing them slightly help the boxes resonate. etc etc.

Your bass response will be best if you keep the woofers close together. That's why guitar amplifier manufacturers started to use 3 or 4 speakers in their combo amps like the Fender Bassman. In that particular example, one of the main reasons for using 4 speakers was to avoid the amp being useless in the even that one speaker blew- the musician would be able to disconnect the bad one and carry on with the gig but the added benefit of 4 speakers is that the bass response and overall output using four 10" speakers was better than one 15".

 

[ZeosPantera]

Well an interesting development. After finding the sound very odd with the four in the series and parallel configuration I took my multi-meter and the speakers are in-fact 4ohm each. Most likely due to the lack of a real crossover. Pictures of what is inside.



The woofer is wired directly to the terminals and the tweeter gets a single capacitor wired in parallel to the terminals. So that is why it is 4ohm.

If you think that makes these speakers junk. They aren't. http://news.cnet.com/8301-13645_3-20016275-47.html They are rather great regardless of the shotty build and mislabeling. (Their Magical)

After a few hours of testing I am going with only a three stack all in series to develop a 12ohm load with the speakers laying horizontal and the woofers on the outside. I placed 1/4" stiff foam mat between them and below to cut down on vibrations between the boxes and from just preliminary testing on the niles amp I think it sounds very good. A larger space and use of the big amp would be the real determining factor in this experiment. In the end I would like to see them used as Front channels in a home theater.

 

[jonnythan]

Sorry, it does make them junk.

 

[j_garcia]

What exactly is the goal? I think you are chasing the wrong rabbit. Yes, I'd have to agree, these speakers looked like junk to me from the beginning, and that sort of confirms it.

A side note - the Audiosource AMP100 is on sale right now for $99 at Parts Express.

 

[ZeosPantera]

The best part about someone saying these particular speakers are junk is I can say "Well spend $29.90+s&h and try them for yourself!"

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-652

Having no crossover between amp and speaker might be part of their magic. I couldn't see buying another bookshelf sized speaker in the near future. The price point would probably need to be in the $1000+ range to actually sway me on an audible difference. The 70hz low end rolloff is the only thing that puts them in a "probably need to go 2.1" category. Best bet is don't underpower them since they are 4ohm and most home amps won't push hard/clean enough.

My opinion remains speaker building is 10% design, 10% execution and 80% luck. If pocket calculators could "calculate" a perfect speaker the best speakers ever would have been made around 1970 and never changed.

TOPIC UPDATE: I finally hooked the series triplestack up to the spec2 today. The results were very positive. Other than a slightly smaller vertical listening cone the notable volume increase and power handling have allowed me to consider this a great success. Imaging is still very good and the high's have not sharpened up to a painful level as I had feared.

I originally started this whole thing because I recommended the Daytons to a friend and he loved them for his bedroom setup but he didn't think they would be robust enough for a larger home theater downstairs. I agreed with that assumption but nothing in his price range could pull off the actual sound quality+volume he was hoping for. So here we are. ~$45 per completed speaker and nothing can match that price with any quality.



As I said, Don't just judge. Try!

 

[jonnythan]

The highs have not sharpened because you're applying the highpass filter to the same signal three straight times!

 

[j_garcia]

LMFAO. I needed a good laugh this morning.

I already knew what these speakers were when I saw them. I was actually thinking about picking a pair of these up for my garage simply based on price, but to say that they compete with ANYTHING decent at ANY price is absolutely ridiculous. Perhaps you could compare it to an actual speaker someone else would know? Because without a reference, you claims are nothing more than claims and the BS meter is off the charts.

My opinion remains speaker building is 10% design, 10% execution and 80% luck.

Your opinion is wrong. Go tell that to the speaker designers on the PE forums and see how well that goes over

 

[ZeosPantera]

Missed this one.

http://news.cnet.com/8301-13645_3-20099395-47/top-10-great-sounding-speakers-from-$30-to-$400

And I am not saying that a very good speaker can't come from the effort and math put into it. But you can't design a great speaker. Quality of sound will always just be an opinion anyways. Like judging art at a museum and stating one piece is better than another just because the frame that holds it is sanded walnut instead of cardboard. Or because the painter was a janitor and not schooled in Europe.

 

[its phillip]

They aren't too bad considering the price.
http://zaphaudio.com/Dayton-B652.html

I know many people who are happy with theirs...but with that being said, I would rather just get one quality pair of speakers instead of buying several pairs of the B652s.