how to hook up 2 pairs of speakers to 2-channel amp

[ogolban]

Hello all,

I have 2 pairs of speakers:
1. Cerwin Vega VS-150: 4 ohm speakers
2. Cerwin Vega CLS-215: 8 ohm speakers

I am interested in the Cerwin Vega amp: CV-900. This is a 2 channel amp with rated output:
8 ohm - 210 W
4 ohm - 320 W
2 ohm - 420 W

I emailed Cerwin Vega's tech support asking them how to hook up my 2 pairs of speakers to a single amp. I've gotten these responses so far:
1. two speakers of same impedance may be connected to a single output (i.e. in parallel?)
However speakers of different impedance may not be connected together
2. they can be connected using speakon connectors (not sure what that means)

Next my friend, Peter, said they can be connected either in parallel or serial:
1. parallel: the new impedance will be: (4*8)/(4+8)=32/12=2.6
Peter says they advertise they can handle 2 ohm.
Is that ture?
2. serial: the new impedance will be: 8+4=12
Peter says this is also okay as long as it is greater than their advertised 8 ohms.
Is that true?

Thank you,
Omid

[bfalls]

What your friend says is true according to the numbers. What you have to take into consideration is the impedance specs are nominal and may drop lower. I would say in general, considering the specs are true, you'd be OK as long as you didn't attempt to drive the speakers too loud. If you're considering this setup for partying you may want to go with an amp with a better reputation and robust power supply.

[02audionoob]

Speakon connectors are proprietary. Read about them here:

http://www.neutrik.com/us/en/audio/204_184671/speakON_Cable_Connectors_productlist.aspx

[ogolban]

1. Which would be a better choice? Connecting in parallel or serial?
I just recognized that I messed up the first posting.
I meant to say that Peter think either parallel or serial would work okay.
Which would be a better choice?
2. Shoud I disregard Cerwinv Vega tech support and that they said it cannot be done?
3. If I drive the speakers loud then I will have problem? What will happen?
What would you consider driving speakers loud?
I don't see myself ever playing the amp at its very high power:
The loudest I played my old amp was 1/2 the power and it was 90W per channel.
Would this be driving the speakers too loud?
4. I have a friend that has been using this amp for his parties for a while.
He really likes it and plays it quite loud.
Don't you think Cerwin Vega has improved their products recently?
5. Do Speakon connectors have a considerable advantage?
They seem expensive and hard to find.

Thank you,
Omid

[markw]

It sounds like you want affirmation, not advice.

You've got pretty good answers to your questions both here and from Cerwin Vega!.

If the company who made all the speakers involved and the amp recommends against it, but you think your friend knows better, well, hey, it's your call. Do what you think is best.

I can't see where speakon connectors would make a difference. We used them in a multi-amped situation when we did concert sound, but I don't see relevance here.

Personally, I would connect them in series. That'll present a nice, safe load for the amp.

[Hyfi]

just use a Niles Speaker selector box and you can run 4 or more pairs depending on the model.

[markw]

just use a Niles Speaker selector box and you can run 4 or more pairs depending on the model.How much power can they handle?

[bfalls]

I agree with markw. The series connections would be less load on the amp. I'm just not sure how running the signal through one then the other in series will affect the sound.

In parallel the original signal is presented at the terminals of each speaker. When in series, the original signal is submitted through one then to the other, but I'm not sure if it's identical to the original, or if the speaker and xover of the first affects the signal continuing to the second. I'm sure there's white papers on this somewhere.

[markw]

The series connections would be less load on the amp. I'm just not sure how running the signal through one then the other in series will affect the sound.I can't say how it will affect the sound, if at all.

But, if ya gotta run four speakers off this amp, it's the safest way.

[ogolban]

Thank you very much for all of your responses. They are all very informative. In defending my silly questions, I'd like to respond to the comment that I want affirmation not advice. I have 2 electronics engineer friends that tried talking to the Cerwin Vega techs. My engineer friends suggested the techs, probably for good reason, were just following some company quidelines in answering questions and that's how we got conflicting answers from them: one tech suggested there should be no problem connecting speakers in parallel then another tech suggested that the amp would overheat and die. Deep down I do like to try this amp. I decided to take my questions to a forum and use real people experiences.

As for how much power can the speakers handle:
VS-150:
frequencey response 28Hz-22KHz
power handling: 400 Watts RMS
Impedance: 4 ohms
sensitivity: 102dB
CLS-215:
frequencey response: 24Hz-20KHz
power handling: 500 Watts Peak
Impedance: 8 ohms
sensitivity: 97dB

Again, thank you very much for all the advice and solutions that you have provided.

[musicman1999]

Speakon connectors are a type of locking connector, mostly used in the professional audio world. My dvd player has BNC component video connectors, so i need to use a locking BNC to RCA connector. Not familiar with Cerwin Vega gear so not sure if that helps but thats what they are.

bill

[02audionoob]

I think what Cerwin-Vega is telling you is to parallel them by putting one pair of speakers on the 5-way posts and the other on the Speakon connectors.

[Hyfi]

How much power can they handle?

The SS-4 is rated at 200wpc while the HPS-4 is rated for 250wpc. They have built in protection circuit if you run all 4.

I use a second set of wires from the second set of connectors on the counterpoint and drive a 6ohm pair of JMs and an 8ohm pair of Athenas with no problem. I used to drive my Dynaudio 82s as well as the JMs and Athenas with my Stratos.

[Glen B]

1. Which would be a better choice? Connecting in parallel or serial?

Connecting in series, especially dissimilar model speakers, may affect frequency response and degrade the sound. You're also increasing the load impedance presented to the amp, and lowering output wattage. If you are using this type of connection for sound coverage (like for a party) and don't care about sonics, then series connection is acceptable. I would not connect a 4 ohm and 6 ohm speaker in parallel. The total impedance may drop too low at certain frequencies to be safe for your amp. I've owned three different 15" Cerwin-Vega models in past years and they all played very loud. What are you doing that you need to use large C-Vs together with another speaker ?


Should I disregard Cerwin-Vega tech support and what they said it cannot be done?
No, because of what I said above about safety.



3. If I drive the speakers loud then I will have problem? What will happen?
What would you consider driving speakers loud? I don't see myself ever playing the amp at its very high power; The loudest I played my old amp was 1/2 the power and it was 90W per channel.
Would this be driving the speakers too loud?

Driving the speakers to high levels into a low impedance stresses the power supply and output transistors and can cause overheating and damage to the amp. If you don't intend to drive the amp to high levels, then why even consider connecting speakers in parallel ? I was a road DJ for 10 years, and the only time I used more than a single pairs of speakers was in really large environments, or at house parties where multiple rooms were used. To reiterate, IMO the combination of VS-150 speakers and 200W+ amp will play plenty loud for all but the most demanding applications.

[Kevio]

You should be able to run them safely in parallel. The reason it is not recommended is because the 4 ohm speaker will get twice as much power as the 8 ohm speaker. The 8 ohm speaker is also less sensitive. The upshot is that the 8 ohm speakers are not going to be adding much to the system in the context of the work the 4 ohm speakers will be doing. Not a good choice.

If you wire them in series, the 8 ohm speaker will get twice the power as the 4 ohm speakers. The less sensitive speaker is trying to do the heavy lifting. The amp won't have enough voltage to drive anything to anywhere near full power. Frequency response will likely be adversely affected by the series configuration. Also not a good choice.

[Smokey]

The series connections would be less load on the amp. I'm just not sure how running the signal through one then the other in series will affect the sound.

I tried this configuration and noticed that not only volume dropped, it also decreases speaker's low frequency response. Not a pleasant setup.


Driving the speakers to high levels into a low impedance stresses the power supply and output transistors and can cause overheating and damage to the amp.

Not to mention added distortion. Current demand will be too great for parallel setup and if amp can't deliver extra current, distortion will be excessive.

[E-Stat]

I emailed Cerwin Vega's tech support asking them how to hook up my 2 pairs of speakers to a single amp.
Setup questions aside, why would you run two very different types of speakers simultaneously?

rw