Help....need advise on M80's with Onkyo TS-DX787

Posted by: amer

Help....need advise on M80's with Onkyo TS-DX787 - 01/24/03 11:50 AM

Folks,

I am seriously thinking of upgrading to the M80's from my current M50's.

The one thing I need to sort out first is will my 787 be able to handle these 4 ohms speakers? Onkyo's manual rates the power down to 6 ohms, but no mention of 4 ohms.

I know someone here must be using the M80's with a 787, and if so what was the result? Were there problems with the receiver shutting off in either 2 channel or 6.1 channel mode?

Any advice would be appreciated.......Amer
Posted by: Semi_On

Re: Help....need advise on M80's with Onkyo TS-DX787 - 01/24/03 12:24 PM

You're fine. They don't spec it because almost no one makes a 4 ohm speaker. The "ohm rating" is merely the load the receiver sees from the speaker. Lower load, means higher power output. I've never seen a modern (or ancient for that matter) receiver that didn't have the proper circuitry to handle the increased power draw.
Posted by: amer

Re: Help....need advise on M80's with Onkyo TS-DX787 - 01/24/03 12:44 PM

Thanks semi,

I think I agree with you, plus all the other comments on the Denon 3802/3 on this board lately seem to indicate I should be fine. But one issue still bothers me. I am working with Marc on audioshop on this purchase. Marc menitoned that Apparently someone with a Onkyo Integra receiver (not sure which one) had problems running the M80's, the receiver just kept shutting itself off. Apparently the guy talked to Axiom, who built him a matching box (?) to raise the impedance (We are not sure if this would effect the sound, regardless I would rather stay away from having to do this if possible). Apparently that problem was talked about on this board a while back, but we can't locate those messages anymore.

In the Onkyo manual it clearly states that 6 ohm is the minimun, and damage could occur with anything less. I wonder if they are talking about at full or high volumes. I suspect they are just being the typical conservative manufacture. I wonder if I will be ok using the 80's at a moderate volume/power level. I think the Onkyo should be able to handle that.

I would feel alot better going ahead with the purchase if someone with a 787 or perhaps 797 running the M80's could get back to me and let me know if they had any problems.

Thanks guys.
Posted by: amer

Re: Help....need advise on M80's with Onkyo TS-DX787 - 01/24/03 01:49 PM

Ok...found this rather insightfull discussion from last october.

http://www.axiomaudio.com/boards/showflat.php?Cat=&Board=tech&Number=6362&page=0&view=collapsed&sb=5&o=0&fpart=

Very informative, and somewhat disappointing to me as an Onkyo 787 owner. I guess the question is will I be able to use the 787 at moderate power levels. I am leaning towards betting my money on the fact that I can, but if murphyman is still around, or any other 787/797 owners read this I would appreciate your feedback.

Thx.
Posted by: amer

Re: Help....need advise on M80's with Onkyo TS-DX787 - 01/24/03 02:19 PM

Well put my money where my mouth is, just bought the M80's. The price from Marc was way to good to pass up. Here's hoping that a newer amp purchase or separates is not to near in the future.....lol. One thing for sure, if I get a newer amp, I think I will be passing on Onkyo. One of the reasons I went with Onkyo in the first place was the reputation for their amps in their receivers. I had thought they are more powerfull and stable than similarily priced Denon/Yamaha items. Looks like that may not be the case.
Posted by: chesseroo

Re: Help....need advise on M80's with Onkyo TS-DX7 - 01/24/03 03:10 PM

amer,
I have an Onkyo DS797 receiver. Although the manual has power ratings listed for 4ohm loads, the setup options within the receiver DO NOT.
Odd thing eh?
They have options for setting the ohms to 8 or 6, but not 4.

However, i have not used the M80s on my system but i have driven 4ohm Kefs on it, not that long ago. It ran them perfectly fine at either the 8ohm or 6ohm setting, although putting the setting to 6ohms did start to create some distortion at the higher end of volumes. When running the Kefs with the 8ohm mode, the receiver still ran at its usual temperature without the distortion.

I have heard about some issues with the 787 model, one specifically that is has a fan to help cool the amp onboard. The 797 model does not have a fan and hence, i'm led to believe that Onkyo changed the heatsink or amp with the newer 797 model from what the 787 had. A fan is often used to assist a heatsink that needs the help. With a large enough, appropriate composite heat sink, you should not need a fan (at least not for this price level of receiver).

All that being said, i cannot say to you for sure that the 787 is a good enough model to power the M80s. I have my doubts based on my previous statements and Murphyman's original accord. Sometimes the specs may lead you to believe it will be fine, and sometimes it just isn't.

But when the M80s do come in, i suggest leaving the receiver set at 8ohms and see if the auto protect circuitry shuts it off at higher volumes or extended play time. I would also suggest checking the heat venting from the receiver during this time so you can get a gauge of how well/poor the receiver is performing. The less hot it is, the better chance your protection circuitry won't become a problem.
Make sure you use a good gauge wire as well (16 or less).
Posted by: Semi_On

Re: Help....need advise on M80's with Onkyo TS-DX787 - 01/24/03 03:25 PM

Integra had some pretty serious design issues in the past couple of years. I've read a lot of complaints to that regard. The new models are supposedly a concerted effort by Integra to regain some of their name, but they did a lot of damage with some faulty heat dissipation, bad fault control and poor feature set.

Too bad really.
Posted by: amer

Re: Help....need advise on M80's with Onkyo TS-DX7 - 01/24/03 03:32 PM

Thanks for the input, ya I will post my experiences with the 787 once the M80's come in next week.

I really hope my first post doesn't have a heading like: "M80's and Onkyo 787.....BOOM!"..............lol
Posted by: Semi_On

Re: Help....need advise on M80's with Onkyo TS-DX7 - 01/24/03 03:41 PM

If there's a problem, it will probably just turn itself off. In that case, you sell the receiver on eBay for the price of a new one (eBay customers are sooo gulible) and get a receiver that can take it.
Posted by: chesseroo

Re: Help....need advise on M80's with Onkyo TS-DX7 - 01/24/03 04:24 PM

NOw that is up for quote of the year.
Posted by: amer

Re: Help....need advise on M80's with Onkyo TS-DX7 - 01/24/03 04:53 PM

guess where I bought my 787 from two years ago........lol. [censored] I might be able to sell it for the same price I paid.
Posted by: Semi_On

Re: Help....need advise on M80's with Onkyo TS-DX7 - 01/25/03 10:05 AM

I wouldn't doubt it at all. eBay is a sellers paradise. I remember an informal study one of the tech TV shows did of eBay and they found that the majority of people were paying full retail for used stuff. I know plenty of people that have found good deals, you just have to be very knowledgeable about what you're buying (good advice regardless in my mind).
Posted by: amer

Re: Help....need advise on M80's with Onkyo TS-DX7 - 01/31/03 05:54 PM

Well my M50's big brothers the M80's arrived today, damn am I happy I went ahead with the purchase. I am stunned by how good these are for the money.

Surprisingly my Onkyo-787 will play these speakers quite loud (loud enough for me....too loud for the wife....lol)before going into auto protect mode (and even then it seems to be song dependant...real strong bass seems to kick it into autoprotect). Heat doesn't seem to be a problem, as its not running all that hot, must be hitting a certain frequency thats dipping below 4 ohms that triggers it (my best guess anyways). Down the road I will be getting a separate 2 channel amp, to see what these bad boys are capable of.

Thanks for all in this thread for the advice, to marc at audioshop for the great deal and service, and to axiom for making these beauties.

Amer
Posted by: amer

Re: Help....need advise on M80's with Onkyo TS-DX7 - 02/04/03 04:49 PM

Hey Semi,

I see what you mean about ebay being a sellers paradise. Been looking at picking up an Adcom GFA-555, 15 year old equipment almost going for what it sold at new. Looks like I may have to start hitting garage sales in the neighborhood........lol.
Posted by: Semi_On

Re: Help....need advise on M80's with Onkyo TS-DX7 - 02/04/03 05:02 PM

It's pretty ridiculous, I know.
Posted by: Marc_in_Ottawa

Re: Help....need advise on M80's with Onkyo TS-DX7 - 02/10/03 01:54 PM

Hi Amer,
Thanks for your business past and present!!!