Help???

Re: Help???

After scanning posts endlessly concerning overloads, I can tell you some of the things that might've worked for others, including myself

-Cleaning the tips of speaker wires
-ensuring your receiver's settings has your speakers set to LARGE and not SMALL
- making sure no extra speaker wire that has no business being attached to your receiver is present.
- setting treble/bass and individual speaker volumes to 0.
- go through your receiver's settings and look for anything set to 'YES' or 'ON' that shouldn't be. ( I had a thing called Panorama CTRL set to 'YES'. I set it to 'NO' and after adjusting a few more things my receiver no longer overloaded)

Hope that helps

Re: Help???

Oh and make sure no speaker wire is touching another on the back of your receiver. That's a common mistake, as is shorted speaker wires. Unplug your speakers one by one and try to isolate a problematic speaker wire, if this is indeed the case.

Re: Help???

those numbers are likely "peak", not "continuous", so your speakers can take (total, individual #'s may vary) 1200W before you damage them, and your receiver can provide 500W to the speaker system (which is probably more than enough to hurt your ears)

is your receiver sitting in some sort of cabinet or built-in shelving? I've seen overheating cause "overload" protection before

how about impedance matching between your receiver and speakers? (there should be some label that says something to the effect of "USE 8-16 OHM" or "USE 6-16 OHM" by the speaker terminals (ohm may be substituted for the omega, wording and #'s may be different)), if your speakers are much lower than the minimum on there, you may need to select a low impedance mode (if available, this would be either a switch on the back or a setting found in the OSD)

Re: Help???

I'm sorry, but there seems to be some bad information given in this thread. Setting your speakers to large vs small will actually make the situation worse not better. Bass frequencies take a lot more power than higher frequencies. Just think about the energy needed to move a large 10-15" driver an inch or two vs what it takes to move a 1-7" driver a few milimeters. If you do not have a sub, then I would still opt to leave your speakers set to large than to just cut out the lower frequencies. In that case, getting a powered sub would probably help considerably in taking stress off of your receiver. Also, you still want to have the correct trims set on your speakers. If you have any speakers set to the maximum trim in a single direction (+ or - 12 or more), then you probably need to figure out the issue, but it is normal and should not cause over-due stress on your receiver to adjust trim on your speakers to get a balanced soundfield. There are a number of threads up right now with suggestions on troubleshooting receiver overload, so I'm not going to dig into all of the possibilities, you can search for those threads or just look in this same forum, they are currently active. I will say that speaker wiring or issues with the actual speakers themselves seems to be one of the biggest issues. First thing is to make sure you have good, clean connections on both ends and that there are no stray strands of wire connecting with the opposite connection. The idea to test individual speakers was a good one.

Also, there are several threads around about using a professional amp similar to what you purchased with home theater equipment. I'm not the expert, but if you search, I'm sure you can find them. The most recent I remember was about using a car sub in a house.

Re: Help???

Hate to tell you this, but I am 95% sure it's the CLS-15s that are causing the overload problem.

I could not find any mention of their impedance - that's their resistance to electricity flowing through them - on Cerwin's website, but many other Cerwins I have seen over the years were rated at 4 ohms or IIRC, sometimes rated as "8 ohms compatible".* The lower the impedance, the more power most amps try to send to that speaker. I used to sell one series of Cerwins back in the mid 90s where the 12" and 15" models had a 4 ohm rating which few receivers under $500 at that time could operate properly, so we always had to make sure the customer bought or used a receiver with a powerful enough amplifier section. Otherwise, they would usually do what your Pioneer is doing: as soon as they turned up the receiver past background volume level - bing! - the receiver shut down.

This is not a bad design choice by Cerwin but instead just a way to help larger amps produce more power.....which unfortunately has a downside for some people.

In general, loudspeakers with 10", 12" and 15" woofers really aren't that much harder to operate for a receiver vs. one with a smaller woofer. And actually it can be easier, since all that extra radiating surface means the cone doesn't need to move as far as compared to a smaller cone for the same amount of bass output. For proof consider all those vintage speakers from the 60s and 70s that were available when a "powerful" amp at that time was rated at around only 40 to 60 watts per channel.

I don't know much about connecting a pro amp to a home receiver, but I have heard it can be done in many cases. But you need to speak to someone who really knows what they are talking about.

Personally I would go for the CLS-10s paired with one of Cerwin's subwoofers. Even if your receiver is set to filter bass from the satellite speakers and to a subwoofer, anyone who's watched a satellite with a little 5" woofer try to reproduce bass - even at 80Hz - at high volume levels knows how uncomfortably far that cone is pumping in and out!!

Re: Help???

So, why do most powered subs come with their own amp of upwards of 200 watts if it takes less power to get bass out of them, and most receivers have a sub out instead of just having another channel at the same or lower wattage for the sub? Especially considering that most subs on the market have a single large driver? So are all the manufacturers doing this completely backwards? Maybe I don't need that 300 watt plate amp I'm installing in my sub this weekend. Many high-end speaker manufacturers also have dedicated built in amps if their speakers have larger drivers. Even my little Def Tech towers have a 125 watt amp each to drive the two little bass drivers in each of them so as to take stress off of the receiver without requiring a dedicated amp to run them.

Re: Help???

1) the bass frequencies that subwoofers are usually used to reproduce - usually those under 30Hz - require MUCH more power than the frequencies the majority of music requires (I can't remember the math involved but it's one of those exponential relationships). And that's true even when a large driver used. Actually when a small driver is used, like with those mini-subs out there with 6 to 8" drivers, they require even more power since to make up for the loss of radiating surface they must move in & out much further to move the same amount of air.

Because including an amp capable of driving even a lower-quality subwoofer would significantly raise the cost of the receiver......and the A/V receiver biz is extremely competitive price-wise so that's a major non-no. Most of a receiver's cost is located in its power supply and its power amp, both sections using many heavy duty parts that just plain cost a lot ----> in particular, the pounds of iron and copper in the power transformer and the supply's large filter capacitors (the two or more large can-like components usually mounted nearby); and the expensive power output transistors and - again - all the metal which makes up the heatsink those transistors are mounted to, along with any cooling fan that may be present.

And there was at least one receiver that DID feature this, and it was sold by Technics in the mid 90s. IIRC the sub channel was rated at 100 watts like the rest of the channels. Technics sold a matching passive sub with a 12" woofer and reportedly it sounded fine, but such a low-powered sub was probably only appropriate for bedrooms and small living rooms.

If no one minded owning a subwoofer that used a 15" driver and mounted in something like an 8 cubic foot box to improve its efficiency at those ultra low frequencies many movie soundtracks use sitting in their living room, they could get away with using a smaller amp. But most people *do* mind, and using a more powerful amp paired with a smaller enclosure solves that problem. The amount of power you need depends a LOT on what size room this sub will be used in and how loud you like to listen to your system. Personally I would stick to the 300 watt amp, unless you're using this sub in a walk-in closet.



You pretty much answered your own question i.e. the receiver doesn't need to strain itself so much to power those speakers. Receivers these days are not built like they were in decades past, where they had to power full range speakers all by themselves with no subwoofer to help them out.* In other words modern designers are aware that most people today will use their multichannel receiver to power small sats with small six inch, five inch or smaller midwoofers with the lowest bass filtered out, so powerful amps just aren't needed.

* and many speakers at that time used the acoustic-suspension bass system, which while providing bass that went very low for such a relatively small enclosure (compared to a bass reflex design that used the same size woofer) sucked up huge amounts of power to do so. Speaker efficiencies for these speakers typically hover around 84 to 86dB, compared to the average bass reflex which are around 88 to 92dB, and the dB scale is exponential so those power differences are very significant. BTW: the acoustic-suspension system is not a "bad" design and to me such a loudspeaker's bass sounds better than most bass reflex speakers - they just need more power to get the job done.

Re: Help???

So, as I tried to say earlier, it would take much more power to try and produce full range sound (speaker set to large) through a speaker than it would to only produce a limited range of frequency (speaker set to small) in the upper ranges.