4 ohm speakers 92db what amp will

[scoopix]

with these speakers. I was told at a hi fi shop to sell the speakers and buy some 8 ohm ones. I had a yamaha rxv 800 and it really didin't have enough power. And it is now dead. What amp would you recomend for these type speakers. Was thinking of
onyko 7200 or marantz 7300

Please help my decision as I am desperate to get a new amp tommorrow

ta Craig

 

[zumbo]

Neither of your choices will work. Those are receivers, not amps. I can't seem to find an Onkyo 7200? An AV receiver that is 4ohm stable is going to cost close to 1k.

The next option would be to get a mid-fi AV receiver with pre-outs and add a 2-channel amp for those speakers. Still looking at 1k.

The next option is to get a used receiver or receiver with amp as mentioned above.

The next option, and the least expensive, would be to sell your speakers and replace with 8ohm.

 

[markw]

You like it loud, doncha?

Most receivers don't really lile 4 ohm loads and kinds say this in their specs.

Now, while some receivers can tolerate 4 ohm loads at moderate levels indefinitely, when you push them beyond their their limits for extended perioda of time they do complain. ...at least until they shut down for good.

If you really, really want to keep those speakers and listen at loud levels, your best bet is to get a receiver with pre-outs and running a rock solid power amp, such a NAD.

 

[scoopix]

Shi.....

Thanks for your feedback A speel mistake on the onkyo I meant sr 702.
Anyhow that is not the news I was after.
But thanks anyhow.

 

[Buckeyefan 1]

with these speakers. I was told at a hi fi shop to sell the speakers and buy some 8 ohm ones. I had a yamaha rxv 800 and it really didin't have enough power. And it is now dead. What amp would you recomend for these type speakers. Was thinking of
onyko 7200 or marantz 7300

Please help my decision as I am desperate to get a new amp tommorrow

ta Craig

Neither. Those are mid line receivers and won't drive 4 ohm speakers any better than your Yamaha. You would need to step up to the Onkyo 900 series or Marantz 9000 series to even attemp to drive 4ohm speakers. The hi fi shop was correct.

 

[Francious70]

But we're talking very sensitive speakers here. His are rated at 92dB while most 8 ohm speakers are rated at 88dB. So ya gotta figure, if he wants to listen at 100dB (quite loud for most of you) his receiver/amp/nano-hampsters-on-wheels/whatevers powering the speakers would only have to put out 8 watts per channel as compared to 16 watts for the 8 ohm speakers.

Paul

 

[markw]

To paraphrase Bill Clinton, that depends on your definiton of "loud"

My loud may be your moderate level.

Remember, for each 3 db increase in peak volule level you need twice the power. That 8 watts jumps up to 128 and 256 watts pretty quickly for some people.

 

[Francious70]

Like me, who can list at 120dB without hesitating. But, for most, 100dB is really loud enough.

Paul

 

[markw]

Well, doing some quick math...

.. .with 92 db speakers, to obtain 119 db he'll need a clean 516 watts.

110 db is needs 64 clean watts.

 

[Francious70]

Yea, but I don't know many people other than bass heads who will listen at those kinds of levels. It's possible for me because I have a 96dB sensitive speaker with at least 600 clean watts going to it.

Paul

 

[Buckeyefan 1]

Sensitivity is all relative. Those measurements are taken with a mic at approximately 3 feet. A lot has to do with the size of his room, the distance he sits from his speakers, and if his room is "live" or "dead."

Try playing a 92db 4ohm car 6x9 3 way off your home receiver. It never seems to get loud. Yet in a car, a factory head unit seems to drive them effortlessly. It's best to stick with 8 ohm speakers for the home, and higher spl levels in the low to mid 90's whenever possible.

 

[markw]

VERY good points.

Sensitivity is all relative. Those measurements are taken with a mic at approximately 3 feet. A lot has to do with the size of his room, the distance he sits from his speakers, and if his room is "live" or "dead."

That stated 92 db is valid at only one meter, directly in front of the speaker, and probably at 1khz. I believe (others may want to verify) that it drops 3 db for every six feet distance. Likewise, off axis listening can decrease that and don't forget the probability that the measurement was only taken at 1khz. You know it only goes down from there...

 

[MacManNM]

That stated 92 db is valid at only one meter, directly in front of the speaker, and probably at 1khz. I believe (others may want to verify) that it drops 3 db for every six feet distance. Likewise, off axis listening can decrease that and don't forget the probability that the measurement was only taken at 1khz. You know it only goes down from there...

Its a 1/r^2 falloff. It falls fast!

 

[annunaki]

For the sake of example let us say that the speakers in question did the 92db 1w/1m with full range pink noise. Even in an anechoic chamber at 12 feet away, the speaker is only at 86db with 1 watt. To get it to 100db (actually 101db) it would now need about 32 watts rms. Take into account that the speaker will now be in a regular room, the demands could go up or down. Chances are they would probably go up slightly. A pretty good quality receiver should be fine with 4 ohms on just two channels, but not all 5 or 7. Remember, impedance is not a constant. It fluctuates with frequency. A 4 ohm nominal speaker could dip into the 2 ohm range on some frequencies.

What kind of speakers are they? If they are Paradigm or Martin Logan you are going to need a serious amplifier section in a receiver. Some Paradigm models have a DC resistance around 3.6 ohm and will drop lower depending upon frequency. (I have a customer who has this problem with Paradigm.)

 

[3db]

The only receivers that spring to mind

Are NAD and Rotel. They are both equipped to drive 4 Ohm loads without burning themselves out. Other than, use a receiver with pre-outs and drive the mains via dedicated amps.

 

[annunaki]

An Outlaw pre-pro/amp combo would work as well in addition to NAD or Rotel.

 

[3db]

Agree with ya

An Outlaw pre-pro/amp combo would work as well in addition to NAD or Rotel.

Yup. Agree with you there. Get the new model 990pre/pro and a model 7100 7x100watts and he'd have himself a top notch system all for a song. I just wish us Canadians didn;t need to pay an exchange rate on this stuf. Life is unfair sometimes

 

[zumbo]

Like I said. 1k or better.

 

[annunaki]

The NAD T743 or T753 are under $1K. If a receiver is desired.

 

[3db]

Have to have the last word huh? *L*

The NAD T743 or T753 are under $1K. If a receiver is desired.

Actually this is a dilemna I'm having.. Do I go with NAD over Yamaha ie a T753 over the RXV1500? I don't think my room is big enough to warrant even 6.1 let alone 7.1 but I don't know wether the YPAO feature makes that big a difference