Opinions On Amplification Mix or Match??

I'm possibly going to Tri-Amp a system and wonder if it would be better to stay with the same/similar amps or match the amps to the frequency/power handling requirements.

The most cost effective way that I see in my situation would be to use something like the Bryston 14B for the bass as 500 wpc in that area should be enough for my purposes. I then would use a Bryston 4B (300 wpc) for the mids and a Bryston 2B (150 wpc) for the HF range.

I could 'tailor' the sound somewhat by using the Bryston 14B stereo or 7B mono blocks which have high damping factors and would exhibit firm control on the huge LF drivers. I then could go to more "refined" amps, maybe class 'A' types for the mids and highs. There is some argument for keeping all the amps the same for a 'seamless' sound quality but, I'm not so sure in that respect and cost could run out of control.

Anyone out there have some insight into this situation???

 

Khorn,

All that I can offer you is this....when I went to purchase my first SS high-end system I did check out the Bryston line. What I learned was that for the same, if not less, amount of money the Classe was by far superior in sound quality.

Not that this will help much but just my 2 cents.

 

I tend to favour McIntosh for the situation that I have in mind but, the Canadian prices are WACKO to say the least. I've also learned over the years that the TYPE of drivers and system react very differently to various types of amplification and, what might sound great over one speaker system is absolutely rotten over another. For instance, the system that I'm currently using Klipschorns are EXTREMELY sensitive to the amplification driving them and brute power without finesse is a recipe for hard, cold fatiguing sound whereas a more refined amp can do wonders with this speaker.

The system that I'm considering isn't as "sensitive" to this as my current one but the great warm and involving sound that the McIntosh amps put out due in IMHO to a great extent on their "autoformers" would sound fantastic but, I DO want to stay married!

 

I have experimneted with bi-amping in the past. My conclusion was that you're better off taking the same amount of money and getting one really good amp. Just think of all the bucks your sinking into three Brystons, you can get a Levinson, Krell, etc and have better sound. There is no substitute for great midrange.

 

The speakers in question REQUIRE tri-amplification, there is no option in this case, see below:

The speaker system I'm considering (a pdf file)

 

I've had Pro JBL/McIntosh multi-amped systems in the past and, IMHO nothing I've had since imparted the same emotional quality to the music. Dr. Floyd Toole who ran the Acoustics Program for the Canadian Gov't and set up the best test bed in North America for speaker design purposes (used by many speaker manufacturers) personally used a similar system to mine at the time and we had many discussions on the subject. He was hired away from the Canadian Gov't by JBL/Harmon and took over control of JBL and their other speaker interests.

I'll get in touch with some people before committing and, of course listen before buying as there is a lot more involved here such as the purchase of the The DSC260 Digital Controller required to run this system. I feel that the JBL "house sound" would have been continued and refined through the years but of course with the massive shekel commitment this will involve I'll do a bit more research.

The whole thing depends upon where I move after buying a new home and, if I have the proper room for my Klipschorns I will stick with them and probably upgrade to the Accusic Arts monoblock amps to match my Accustic Arts pre-amp.

I'm considering the JBL as an alternative if I don't have the environment (read corners) for the Khorns.

As you might gather from the above I'm quite mad really!

 

Hmmm....... you look rather sane in your avatar!

-Jeffrey

 

Yeah, I stood too close to the mirror while shaving the day that pic was taken!

 

One thing I found disconcerting about the JBL's performance was that it's usable frequency response is only to 35 Hz yet the literature also suggests that the owner won't need a subwoofer.

If you get a chance to audition these, take your Mondo Head SACD with you, and determine whether you can live without those bottom 20 Hz this speaker system cannot reproduce.

How much are they?

 

One thing that I have found out over the years is that quoted specs are quite different in reality depending upon where they come from. Serious pro stuff in most cases is stated to "qualified" parameters whereas "hi-fi" stuff can be very ambiguous. You also have to consider the real word output capability, roll off curves and other factors including the space the system is "loaded" into in determining what the true capabilities are. For example if let's say one system is rated +/- x# of db at 35 Hz with an output capability of 120 db at that frequency, even with a roll of, it could be producing much higher output 1/2 octave below that than a speaker rated flatter to that lower frequency but only able to put out maybe 95 - 100 db maximum at the frequency claimed.

The LF response is related to the volume of the enclosure and also any electronic frequency curve application (read EQ) that is used. The JBL 18" LF medium efficiency speakers have traditionally been capable of a really usable LF response down to about 23 Hz when LF tailoring and/or a large enough enclosure is applied.

In other words numbers mean very little if an even playing field is not in use. The average home speaker's specs are meant to relate to relatively small spaces (3000 - up to maybe 4000 cu ft) and MUCH lower reproduction levels at all frequency ranges than what we are talking about with this system. Rremember also, this is a complete system, not just a pair of speakers.

Yeah, the proof will be in the listening. To bad I don't live in Northridge so I could go over to JBL and check it out. I will track down a way to audition this system if when I move and decide that I have to change.

Maybe one of the group who lives near JBL could check it out if you have the chance. (just a thought).

Price: well, I think for the complete system (speakers, amps and DSC)specially if I were to consider using McIntosh amplification (preferable) were are probably talking new car territory but, I'll be checking it out.

 

The LF response is affected by one other crucial element: the room in which the speaker is placed, and its placement in that room.

Are you suggesting that your new home will have a listening room about the size of a basketball court, Khorn? (My listening room is approximately 6514 cu ft.)

My presumption from your other comments is that you intend to play the system at very loud levels. The JBL spec sheet you provided claims an efficiency rating of 99 dB, yet they recommend a 1200 watt amp for the 18" driver. By my quick calculation that would mean you could pump 130+ dB into your listening room. Is that loud enough?

What kind of new car purchase would the acquisition of this system resemble most? A BMW or a Rolls?

You might want to take a look at this:

http://www.Audioperfectionist.com/PDF files/journal2rl.pdf

 

The space the system is loaded into reflects much more than just the LF response. Most people don't realise how limiting a factor their rooms are to the sound frequency reproduction as well as the level at which they can play back music without running into problems.

In a home environment one of the most practical ways of reproducing music with good all round results is to set up a "near field" situation. This can be accomplished relatively inexpensively in comparison with trying to reproduce music, specially large scale or electronic, at "realistic levels".

An easy test of your environment is to take a recording of voice ( I find Bob Dylan a good source 'cause of the unique qualities of his voice) and, start playing back a song at really low levels listening from as close to your usual position as possible. If this test can be accomplished your eyes closed it might help lessen distraction and provide more concentration. Slowly increase the volume level and listen for any changes in the attributes of the voice such as timbre, clarity and the overall character. At one point you will start to hear a change where the voice is not quite the same and not as clear and definitive. It'll sound less like Dylan as you know it. Back off slightly to the "break point" where the voice "sounds right" to you again. That's the max that the room/system can handle without some sort of "treatment". This is by no means an all encompassing test but, its a good place to start.

There is no advantage to setting up a system capable of high repro levels if the space its loaded into reaches its limits way below the systems limits, unless of course that is the level that satisfies you. Above that you have to start thinking acoustic alteration.

I happen to like the "Sound" that I have obtained from the pro JBL stuff I have used in the past. I'm talking about a total musical presentation that involves me on an emotional level. I feel more like I'm listening to "real music". There is a certain "weight" to the presentation and I'm not just talking bass here. Heck obviously its not for everyone and I'm sure that I'm in the minority in this respect however it me myself that I have to satisfy in this respect not others.

You must have one great listening space. How much height does your room have?

Is this thing going to be expensive? Heck yes, but, if I move into a space that negates the use of the speakers that I have now I think that will be the direction I go in. Hell, you only go around once so why not try and make the best of it that you can?

As far as the power levels that will suit me in this case they will probably be something like 500 wpc LF + 200
- 300 wpc MF and 100- 200 wpc HF. I really like the sound of the McIntosh "autoformer" equipped amps with JBL but, up here in Canada the prices for Mc amps are pretty heavy but, I might still go there if I can. Power doesn't just reflect the ultimate loudness but more importantly the 'Dynamic headroom capability' of the system which can be heard at relatively low playback levels. many would be surprised at the power draw of just short term peaks under "normal" home listening conditions even with relatively "efficient" speakers.

Anyway, thats some of my take on it and I guess I've babbled on enough for the moment.

Thanks for the link I've saved it and it looks like it'll make some interesting reading.

 

The room is the most important component. That's a fact!

Near field listening is, perhaps, the ONLY way for the majority of listeners to hear what their systems can do in the typical home. Hence the link to audio perfectionist for those lookers-on who are inquisitve.

Another easy test of your environment is to fill a variety of different sized glass jars with coins, and have someone walk around the room shaking one of them at a time as you sit and listen to the variations in the sound. The easiest is, of course, to snap your fingers.

I know of no room that cannot benefit from some acoustic alteration, be it as simple as moving a few pieces of furniture in or out of the room, or as elaborate as reinforcing the structure of the walls. (Again, for those interested in ways to do this, try the audio perfectionist link provided.)

If you wanna make an omlet you've gotta break some eggs. Listening to real music with weight/body at authoritative levels requires sufficient current (as well as power) to sustain a proper signal throughout all of its various machinations. That's one of the reasons I've never succumbed to the temptation to try any of those flea-powered SET's.

Yes, with all due humility, I've never heard a finer listening room. It's asymmetric with a 12.5 ft ceiling. The speakers sit roughly 9 feet from both the side and rear walls with a similar amount of space between them. The subwoofers (you need two for proper stereo playback) are placed in the corners as conventional wisdom dictates they should be. Eventually, I will be acoustically altering the environment by reenforcing the walls, perhaps with brick or cement placed between the studs. This should enable me to clean up that bottom octave a little more.