I am on a budget, and I am in a quandry. Being located abroad far from any hi-fi store where I could test products, I have become obsessed with upgrading my surround audio system for music and DVDs. I have already pretty much made a mistake on an impulsive buy through ebay. I bought some older B&W DM610i speakers, which are rated at 4 ohms. Being a newbie, I thought this was a great deal, but it turns out to be at about the blue book value. That being said, now I am faced with a 4 ohm speaker issue. I have two choices: 1) re-sell the speakers and re-coup the money; or 2) start building a system that can handle 4 ohm speakers. Here, I want to ask some questions related to the second option.
I have looked around for surround receivers that can handle 4 ohms, and pretty much the only ones that promise to handle such a load are the NAD (T743 and up). My other choice would be to use components (i.e. a receiver with pre-outs plus an amp). I have seen a decent deal on a used Adcom GFA 7300 5 channel amp (rated 60 wpc @ 8ohms and 90 wpc @ 4 ohms), and I assume you use this by pluging each channel into the pre-outs of a receiver. Should this sound better than using the internal amp of a receiver? If so, will the quality of the receiver matter as long as it has all the needed surround features? If I am using preouts, can I also use the internal amp of the receiver to power speakers in another room?
Or, does it just make sense to buy a refurbished NAD, which is pretty much in my budget (as long as it really provides sound worth the money). I am looking to building an all B&W speaker system to go with whatever amp/receiver or receiver option I use. Gurus--please help!
If you keep the 4 ohm speakers you should buy a NAD receiver. If you sell the speaker you can buy a lot of different receivers, as long as you buy reasonably efficient 8 ohm speakers (at 88 db's or better). The higher the efficiency the less power is needed. There are a lot of excellent 8 ohm speakers out there.
Of course, the NAD receivers are good for 4 or 8 ohm speakers. You just don't have to spend as much as the NAD if you go the 8 ohm route.
I wouldn't bother with the multi-channel amp. I would just get the appropriate receiver for the speakers, or vice versa.
Some people would say that you would benefit from buying a NAD anyway. To me that is only true if you buy a receiver that clips under the speaker load. As long as you buy a receiver that has more than enough power for loud listening (and doesn't clip--or clips very rarely) there should be little or no sonic difference between the same speakers. The speakers are by far the most important components you will buy.
A properly designed amplifier or amp section of a receiver should have no sound of its own. Obviously you will hear a difference if the amp section clips or the manufacturer made a design that colored the sound (which I think is a bad thing).
By the way, my speakers are 4 ohm at 89 db. Does that make them fairly efficient 4 ohms?
So, you think the receiver is not that important. I know some say there are serious differences in receivers, and alot of them say that the NAD is warmer than many others.
It makes them slightly above average efficiency for 4 ohms. But I would still get a NAD receiver if you keep them, just to be sure. I have talked to Alan Lofft at Axiom speakers and he says he has driven his 4 ohm Axioms using HK and Denon receivers with no problem. But that is using his Axiom 80's and they are very efficient--95 db's. When you consider that every 10 db's is a doubling of perceived sound loudness--that is a huge difference. So he needs much less juice to obtain the same loudness. He also didn't say which HK or Denon he used. You might think it worth the gamble to try the HK 525. But that is strictly up to you--I make no promises.
As long as the receiver is well made and doesn't drop significantly in the power envelope (with all channels driven simultaneously), all well-made amps sound the same--unless they were purposely messed with.
Now a NAD receiver has a soft-clipping circuit, so if or when it clips when driving speakers, it will have a more rounded soft sound--not harsh, as most solid state amps are. That could be one reason some people like tube amps--they clip softly. Some tube amp manufacturers also mess with the output, alterring the sound. Bob Carver has done this on some of his solid state designs (under the Sunfire moniker)to appeal to those that like the so-called tube sound. And many people just imagine they hear something--power of suggestion and power of authority, as many high end tweako publications push tube amps (as they give a lot of advertising).
But I have played my Monitor Audio GR10 speakers in stereo with an expensive Aragon amp, with a Pioneer Elite 49TXi (also high-powered and expensive) and an el cheapo Sony--about $250. As long as I didn't push the volume to the point of clipping on the Sony, it was indistinguishable from the expensive products. And there is a good reason for this, as there is no audible difference in the non-clipping performance. Obviously, the Sony would clip a lot at higher volumes, so it was not suitable.
There have been hundred of double blind ABX tests that have proved the above statement, but you will rarely get anyone to admit it and most people have never used a double blind ABX test to honestly tell the difference. To do an accurate ABX test the volume should be set to within 0.15 db's of each unit (people with normal hearing can definitely tell the difference of 1 db and will usually say the louder one is better) and obviously a disintereted third party has to administer the test.
There are a number of famous stories about this, one involving an audio salon owner in Florida named Kipser. Tom Nouisaine, a well-known audio/electric engineer and writer, on a challenge flew down and brought an inexpensive receiver to go up against Mr. Kipser's very expensive rig. Mr. Kipser picked the cd's and LP's he wanted to listen to and Tom hooked everything up to the ABX tester component which hooked up to his expensive preamp/amplifier and to the el cheapo receiver. Nousaine matched the volumes between both units to 0.1 db's.
They ran this test a number of times. They did about 4 different trials, each consisting of 10 switchings. The best Mr. Kipser could do was guess his rig 6 out of 10 times. On one he did 3 out of 10. Kipser was angry and said he didn't have much sleep last night and other excuses. And of course he started fabricating what happened to the Stereophile and Absolute Sound crowd.
Basically, the high end crowd wants to see what is playing and then tell you how it sounds. Otherwise they generally end up in "the emperor wears no clothes" or the "Wizard of Oz is a guy behind a curtain" scenario.
They mostly fall back to the presumption--"It is a $15K Musical Fidelity or Bel Canto--it has to sound better". Almost all these presumptions have to do with belief systems, marketting BS, supporting the non-science behind the self-annointed golden ears, etc. This is not to say I wouldn't rather have a Krell over a Denon or Sony and that it isn't a better unit. It is just that when played at non-clipping levels there is no sonic benefit.
I didn't say a receiver isn't important. But what is important on a receiver is that it accomplishes the following things for a user to be happy with the sound and experience: a well-made power supply that can play as loud as you want and almost never clip (never clipping would be ideal--but you pay for it), it has the formats and features you want and they are implemented properly (they measure well--some don't), it has a remote that is easy and comfortable for you to use.
If you get a receiver that does all the above and you get speakers that allow it to perform within those parameters---you will be a happy camper.
The point is--match the features, the format, and especially the power envelope to the speakers you buy. One reason why buying 8 ohm speakers that are over 88 db's in efficiency (90 or above, even better)is a good thing. It allows those on a budget to get a reasonably priced receiver that is well-made. It isn't necessary to go in debt to get very good performance at a reasonable price. On speakers though, you can spend a lot of money to get truly great ones. But you can get very good ones (as long as you don't ask them to do things they can't do well)for $300-$500/pr. Certainly, don't expect most small bookshelf speakers to fill a large room with tremendous sound.