AVS Forum banner

Status
Not open for further replies.
1 - 15 of 15 Posts

·
Registered
Joined
·
71 Posts
Discussion Starter · #1 ·
This January's Stereophile's Guide to Home Theater features an equipment report on the Musical Fidelity M250 monoblock power amp reviewed by Michael Fremer pg 78.


In his review, he discovers a long lost secret to improved sound quality. He compares the 5 amps' sound quality using the same speakers and set up, but varyies the lengths of either the speaker cable or the RCA connectors. He concludes that having long runs of RCA interconnects and short runs of speaker cable yields FAR better sound than the reverse IE short RCA connectors with long speaker cables.


He strongly advocates using a monoblock amp near each speaker connected by very short runs of speaker cable. This type of setup was widley advocated in the early 80's in various high end stereo mags. It is interesting to see it pop up again in Home Theater applications!!!


Are other, perhaps more high end amp builders going to follow suit? Has Mr. Fremer turned the current home theater audio set up guidelines on their ears? Should we request long runs of RCA cable in our new theater setups instead of speaker cable? If so, we also then need to provide an electric plug for each proposed speaker and amp used!


Can 5 cheap monblocks provide better sound quality in a home theater app than one expensive 5 channel amp????


This concept could be revolutionary and warrants further investigation.
 

·
Registered
Joined
·
1,681 Posts
It sounds like the perfect recipe for groundloop induced hums ;)


-Steve
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #3 ·
Ground loop hum certainly is possible/probable?


I think this new technique rewuires a total revamp of how we set up our theaters. Including a review of currently manufactured RCA interconnects. Long runs of interconnect cable must play havoc with the preamps driving it, I would think. FM interference, ground loop interference, dimmer switch interference, etc etc. must come into play as well. NOt to mention the cost issue. Most interconnect cabling is more expensive then speaker cabling on a ft by ft basis. Moreover, it is much more difficult to find longish runs of RCA type interconnect than speaker cable.
 

·
Registered
Joined
·
1,735 Posts
This problem is easily solved with the use of balance cables. Most monblock designs have provisions for XLR type connectivity, and a company like bryston also allows 1/4" TRS. Despite the theoretical and/or perceived difference, I believe if a system is correctly designed the benefit of this type of change would pale in comparison to a room that is well designed acoustically.
 

·
Registered
Joined
·
1,284 Posts
Is it a long lost secret? I thought audiophiles are still doing this on a daily basis. It might be a big discovery to the HT world, but many HT owners who has dedicated front channel amps go via the amp right next to the speaker route.


Ground loop issue would not be exacerbated with the longer interconnects.


And high quality speaker wire cost much more than interconnect of similar quality. I don't mean the in the wall bottom of the line type of speaker cables.
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #6 ·
Dan,


You may be onto something there with XLR connectors. I know that they are used in almost all pro level sound equipment. Longish runs of interconnects may be exactly why they do. Rock concerts, studio recording, radio and tv stations etc. The newly reviewed Musical Fidelity 250's do NOT have this type of conector available.


As for a properly set up room, I would agree, but what if your room is already properly set up acoustically speaking and you want the best sound possible. Mr. Fremer suggests 5 mono amps placed near the speakers is the way to go. As long as you have the proper room, why not set up your amps proerly as well?


Mr. Lwang,


I strongly disagree with your statement that most audiophiles have this set up in their home systems. In fact, I would bet less than 5% of all audiophiles even use monoblock amps. I can't remember the last time anyone from Stereophile or any audiophile mag suggested setting up monoblocks in this way. I do agree that high end speaker cable is expensive ( kimber bifocal XL sprins to mind), but when is the last time you checked the price of an equivalent interconnect and then requested a custom made length of, say, 20-30ft times 5?
 

·
Registered
Joined
·
1,681 Posts
Quote:
Originally posted by lwang



Ground loop issue would not be exacerbated with the longer interconnects.

It is not the long interconnects that I worry about. It is the 5/7 different outlets (not to mention the outlets for the equipment).


-Steve
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #8 ·
Steve,


I've done some more research on this subject and have found out a couple more things.


Don's suggestion of going with balanced XLR connectors instead of unbalanced RCA type interconnects will help to eliminate groud loop hum and RF interference issues. 5-7 extra power outets is an interesting added issue isn't it, but not difficult to accomplish if you are starting from scratch on a home theater.


Monoblock amps are made by most higher end amp companies, however, they are mostly very high dollar items. It would seem that if you want a reasonably priced mono amp with balanced XLR connectors you need to look no further than Bryston. Bryston offers three models from 60 watts mono to 250. This is their Powerpac line. Additionally, they make their own balanced XLR interconnects. A 30 ft pr runs about $450. So, 5 runs of 30ft balanced XLR would run about $1100 total. Less if you need less length. The very nice thing about these Bryston Powerpacs is that they can be mounted on a wall or even on the speaker itself. Moreover, if money allows in the future, you can use another set of 5 and biamp your speakers.


I think these mono amps are the wave of the future for dedicated home theater. Manley is even getting into the game with a mono tube amp. I predict that the Adcoms, Rotels, Classe' and the like will jump on this bandwagon within a year, and all will offer $1200 or less high powered monoblocks with balanced XLR connectors. The only other option that makes sense is the Meridian DSP 6000 and 8000 systems. Most speaker manufacturers don't have the ability to pair dedicated amps to their speakers though.
 

·
Banned
Joined
·
8,738 Posts
Quote:
Originally posted by lcdrules
This January's Stereophile's Guide to Home Theater features an equipment report on the Musical Fidelity M250 monoblock power amp reviewed by Michael Fremer pg 78.


In his review, he discovers a long lost secret to improved sound quality. He compares the 5 amps' sound quality using the same speakers and set up, but varyies the lengths of either the speaker cable or the RCA connectors. He concludes that having long runs of RCA interconnects and short runs of speaker cable yields FAR better sound than the reverse IE short RCA connectors with long speaker cables.


He strongly advocates using a monoblock amp near each speaker connected by very short runs of speaker cable. This type of setup was widley advocated in the early 80's in various high end stereo mags. It is interesting to see it pop up again in Home Theater applications!!!


Are other, perhaps more high end amp builders going to follow suit? Has Mr. Fremer turned the current home theater audio set up guidelines on their ears? Should we request long runs of RCA cable in our new theater setups instead of speaker cable? If so, we also then need to provide an electric plug for each proposed speaker and amp used!


Can 5 cheap monblocks provide better sound quality in a home theater app than one expensive 5 channel amp????


This concept could be revolutionary and warrants further investigation.
If you are going to investigate, I suggest that you get 5 mutli-channel amps and a 5 channel amp in one chassis and conduct a properly set-up double-blind level matched listening test, if you can detect a sonic difference between in an A/B test, the next thing you must do is decide which sound you prefer. That is the only way to truly know if sonic differences are real or if Michael Fremer is just blowing smoke.
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #10 ·
Mr. auditor,


Your listening test does have merit, but why the 5 multi channel amps versus the one 5 channels in one chassis? why not compare the 5 monobloocks to one multi channel?


Fremer convinced himself of the merit of 5 monoblcks placed close to the speakers by using the same amps in two different configs. In the first config, he took the 5 monoblocks and placed them near the preamp with short interconnects and attached long speaker cables to the speakers. In the second, SUPERIOR SOUNDING, config he took the same mono amps and placed them next to each speaker using long INTERCONNECTS and short speaker cable. Sound level matching would have indeed ben important, and he did not mention that he did this.


If you do some research on this subject, you will find that most amp companies and speaker manufacturers readily admit the merit of Fremer's personal observation. Meridian has taken this philosophy one step further in their DSP 8000 line of powered speakers.


This all has very important sound quality implications specific to home theater applications. Much more so than in a regular audiophile stereo set up do to the inevitable long runs of cable found in a home theater. I predict we will see much more of this in the future.
 

·
Registered
Joined
·
1,668 Posts
I must side with lcwang. The main purpose of a monoblock, in the audiophile world, is so that you CAN put the amp right near the speaker. Most people who have monoblocks do this, or else they probably wouldn't have bought them. The better quality amps are essentially monoblocks internally, the purpose of getting them in separate packages is to put them near the speaker.


It is known that people in the HT world have long rejected this approach. Some good brands of amplified speakers (the "ultimate" monoblock app) have been discontinued due to lack of sales. Even though some were highly praised, HT'ers didn't buy in.


It would be a good idea in this RF-noisy world to use balanced cables for this approach. Ground loops are the least of your problems, it won't make any difference how long the unbalanced connection is, if there's a ground loop, there's a loop, length of loop doesn't matter. It's noise pickup that balanced reduces.
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #12 ·
Mr Fraser,


I believe you, Mr Fremer, Mr wang and I all agree that mooblocks placed near the speaker is THE approach to take for ultimate sound quality. I simply disaggreed with his statement that most audiophiles do things this way, because most can't afford to!!


Now, however, we will begin to see properly set up, affordable, quality monoblocks for use n the multi speaker home theater/SACD/DVDaudio surround sound applications simply because of the requisite LONG cable runs required of this set up.


In a normal, audiophile two speaker set up, the benefits of the monoblock arrangement are less likely to be realized simply because ALL cable runs are relatively short. Speaker cable, in general is kept to 8ft or less. In a surround sound app, speaker cable lengths can be 25ft or more in most apps. Thus, it is in this setting, that monoamps near speakers makes a ton of sense and will be the wave of the future as soon as the public can wrap their collective heads around the idea. The only thing I don't like about the all in one, powered speaker approach is limited flexibility and upgradeability.
 

·
Registered
Joined
·
1,668 Posts
Totally agreed lcrules. Monoblocks do cost much more, even when they are "monoblocks" in the same chassis. Since I do not have a purpose-built HT room, though it is a dedicated room, I cannot see monoblocks in my future. There is already too much stuff in the room, I can't see having amps sitting near speakers, then there's the amp power routing problem (IMO one of the reasons powered speakers didn't sell well, along with the inflexibility). The reality for the vast majority of people is all the amps in one place, near the processor, and hidden speaker cables...much easier to do, and neater.
 

·
Registered
Joined
·
1,284 Posts
I don't have monoblock amp, but I do leave my L/R amp between the speakers, and run moderate interconnect to them. Long interconnect runs from my pre/proc to the amp. A FPTV/drop down screen helps in that.


I guess it all comes down to whether you come from the Audio world or not, and how much a die-hard when you were in the audio world.
 

·
Registered
Joined
·
1,668 Posts
Sorry for spelling everybody's monikers wrong...:)


Anyway, I'm sufficiently an audio diehard that I won't run any "good" audio sources through a processor. But instead allow the HT front L/R sound to be very slightly more compromised for movies, while being better for music.
 
1 - 15 of 15 Posts
Status
Not open for further replies.
Top