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In Reply to: All TACT system or DEQX plus conventional amps? posted by topher_m on April 24, 2007 at 14:04:25:
1). DEQX with Parasound JC-1 for bass, A21 for mid/high (eventually ad something else for tweeter)
Pros - more "conventional" technology
unlimited power (400W+250W+top)
Cons - more complicatedAs one who has an three way active rig, I feel that I can comment. Is there any reason why you wouldn't just actively drive your B&Ws? And if you don't already have them, what made you choose the JC-1 for the bass?
Not that they would not quite well. If you are buying the JC-1 specifically for that purpose, you can probably save some $$$ and buy something more reasonable. $$$ saved = more music. Pretty much any amp over 200 per side will do your bass just as good. Without the low pass crossover to contend with, any "good bass" amp should suffice. I had an old HCA2200II laying around. Effortless bass at any reasonable level. Heck, any level.
On the mids, 100 real watts should be more than adequate. You can choose. My 50 watt into 8 (usable 100 into 4) Plinius does just fine. Above 1 KHz, the demand drops off at 3 dbs per octave, so you might consider a single ended pure Class A design. Yeah, I know, a redundant term. The little 30 watt Pass Aleph 30 (45 into 4 ohms), 900 bucks on the internet, will light up your tweeters like any amp out there, regardless of cost. Tubed included.
As far as mixing and matching of amps, the tonal differences between drivers (and passive crossover interaction) is probably greater than those of properly chosen amplifiers. Anyone who disputes this, and is not running a fully active system, come on over... I'll make you cry.
When you go fully active to any speaker, you are taking it to the extreme. Screw the tip toe and bi wire crowd. They are making a difference that is akin to bolting on headers, if they are lucky. Fully active, you will be boring, stroking and blowing that motor. Be ready to be pinned back into your seat like no cable swap will ever do. For the absolute best and most informative info on the subject, go here:
http://sound.westhost.com/bi-amp.htm
Trust me, you'll soon be laughing at the LP vs CD, tube vs SS debates.
Follow Ups:
HiPlease give me a bit more.
I already have the JC1's so I am in a bit of a bind. I would not have bought such a powerful monoblock if I thought I would have gone in this direction eventually but here I am. 400W seems excessive for mids so I was thinking bass but you are right, a bit of a waste there.
That's why I was thinking about selling the JC1's to get the S2150X for the mids and highs but you are right again - I believe a flea tube amp would probably be best for tweeter.
See the bind?
The DEQX allows for the use of conventional amps which I have some but not the best match for application.
The TACT is simplier to use but it requires their own digital amps to get crossover capability.
Yeah, the JC-1s are overkill for such a configuration. Do you really need that flea tube amp? I presume you want it for the airy highs that they supposedly provide. If your front end and pre amp are up to the capability of where you seem to be going, you don't need to induce air via 2nd order harmonics into your system. With an active config, what is extracted off of the storage medium is what you will get. If there is room air there, you will experience it. No need for artificiality. The little Pass for 900 beans puts me there, with headroom to spare. Any potential gains in sonics of a small tube amplifier are more than offset by the huge gains in going active with a properly executed small pure class A SS amp; preferably single ended.As far as the DEQX. Is there any specific reason why you want to use this one specific box for your crossover? Not that it isn't a good unit. My current speakers have the DEQX as an option. There are many good non digital ones out there. I am quite happy with the el reasonable Marchand, as many others are. Marchand does have an active tube crossover as well, that was good enough for Harvey Rosenburg. As far as room acoustics fixes for the low end, you can use an analog three band parameteric on your woofers only. Whether or not it is absolutely transparent is irrelevant since it will not be used in line with the mids or tweets.
For a little more than you could probably sell your very fine Curl amps, you can probably get three suitable amps, an active crossover and an eq for the lows. I use a Legacy Steradian unit for the area between 40 and 80 Hz, where room boom occurs. It suits me just fine. Not that I necessarily recommend it, but I can tweak the low end to suit not just the room, but for differences in recordings as well. No need to get up and down to tweak my sub from disc to disc.
Do have a read on the link I sent you yesterday. The absolute best information available for bi and tri amping out there.
Hi Ozziethanks
I agree about the flea powered tube vs likes of a Pass First Watt type design. I actually have had an eye on those for a long time but the application was so far away from what I needed they were moot.
My gut right now is to go with the DEQX with the Parasounds - JC1s on bass, A21 on mid and eventually something different on top.
I am still a little daunted by DEQX but I guess the Marchands really don't leave the flexibility to test a bunch of different xover freqs - kind of need to know where you are ahead of time. I have heard nothing but good things about the quality of their product but I don't think I want to deal with the much less friendly tweaking vs digital.
sounds like you an analog guy for source. I run direct from a pc so I am pure digital. Seems like entering a bunch of analog back into the equation might be moving in a different direction.
Gotta make a decision one of these days!
I suppose having 650+W per side in a triamp can't be all bad for dynamics.
topher, Actually flexibility is the best characteristic of the Marchand. You can choose your own crossover frequencies and slopes. Like the DEQX, you can even mix and match the slopes. Say 24 Db for the woofer low pass and 18 Db for the mid coming in. Just trying to help you save a few $$$ if poss and get the same result you are after. I am running 24 Db slopes all around. Tried others and frequency crossover points, but came back to 24 Db slopes at the stock crossover points.I only have a digital front end. An old Sony 777 modded to sound pretty darn good. As far as the power, when you go active, you will be running less than -10 Dbs of peak power at any listening level. I have 385 on the woofers (300 Hz on down), 100 pure Class A on the mids (300 Hz - 3 KHz) and 45 single ended Class A on the tweets (3 KHz on up). I once took a measurement of the tweeters output. With a peak and hold meter I registered something like 2 volt peaks (1.85 actually). Seriously! That is less than 1 watt peaks. So the amp is sluffing along at any volume setting, thus making the argument of which amplifier design overloads more graciously a moot point. If you don't overload in the first place, there should be no artificial peak limiting ala flattening the wave form (tubes), which as we all well know, is distortion in and of itself.
I have run across his articles before - very good.I have the next week or so of reading covered.
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