Two 2-ch set-up in one room

Well, last night I was feeling bad for the NAD amp and decided to try setting up a second system in the same room without disturbing the LSi. I sit right against the back wall and have the RT800i beside the couch. What I did was hook up the NAD to the ASL with a Y-adaptor and hooked up the RT800i to the NAD. So now when I want to listen to the 800i, I take one of the chairs and place it right in front of the TV.
My question now is...Should I place the amp closer to the 800i's and use a longer interconnect or leave the amp where it is now and keep using the loooong run of speaker cables? The 800i's were used as surrounds when I still had my receiver.
Maurice
My question now is...Should I place the amp closer to the 800i's and use a longer interconnect or leave the amp where it is now and keep using the loooong run of speaker cables? The 800i's were used as surrounds when I still had my receiver.
Maurice
Post edited by organ on
Comments
Reasons:
Cost.
Signal strength.
Tour...
Vox Copuli
Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb
"It's easy to get lost in price vs performance vs ego vs illusion." - doro
"There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
"Death doesn't come with a Uhaul." - Dennis Gardner
madmax
Avantgarde horns, 300b tubes, thats the kinda crap I want...
Seriously, your polar opposite opinion has made me stop and think. So what did that get me? I think whereas you are coming from an emphasis on transmission signal loss, I was focussing on unwanted additions to the signal, i.e., acquired noise.
On your resistance position, I'm seeing that in either case the resistance of the "wire" is much, much smaller than the impedance of the load, less than 0.0001 ohm vs. loads of 4 and 40,000 ohms respectively for speakers vs amps. So, yes, you are correct in that wire resistance is "more" negligible in the case of the IC's by a factor of 10,000, bit in either case the wire's resistance can mathematically be argued to be negligible.
Where I am coming from is that in the case of a 4 ohm speaker, a 1 watt signal produces a voltage potential of 4 V and a current of 0.25 amps (250 mA or 250,000 uA). If we assume a nominal 100 W amp with a "typical" input sensitivity of 1.5 V at rated output, then the corresponding input signal for the 1 W output would be 0.015 V. At the 40 kOhm input impedance this corresponds to an input signal of 0.000000375 amps (0.375 uA). Obviously the IC's 100,000 times lower signal strength is more susceptible to interference.
So on one hand we have a 10,000 times edge against loss of detail, and on the other a 100,000 times edge in significance of noise gained. In the final analysis it may come down to the effectivnesss of the IC's shielding vs. how much detail we can hear.
Please feel free to check my calc's, assumptions and approach here. I am really looking for a dialogue and an education...
Tour...
Vox Copuli
Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb
"It's easy to get lost in price vs performance vs ego vs illusion." - doro
"There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
"Death doesn't come with a Uhaul." - Dennis Gardner
BDT
...disclaimer...
This is just my take on the whole fiasco of mating components. A lot is still to be learned and all ideas subject to change immediatly without notice.
madmax
Avantgarde horns, 300b tubes, thats the kinda crap I want...
LINK
Actually I think you may be crediting me with a deeper analysis than I performed. All I was trying to do was get a feel for the relative current involved in the transmission of the music signal for the IC vs. speaker run options. Just strikes me that the lower strength signal has greater protential to be "compromised" by RF. In retrospect, I guess it was a relative S/N exercise minus any specifics about the noise source's strength.
I've experienced "hum" due to speaker wire runs paralleling AC wiring and due to similar TT to phono stage connection issues, an even lower signal strength. The former could be masked by increased music volume, whereas the latter... well, not.
Agree about the potential of connections overriding the length of IC or wire runs in any noise concerns. And I have also noted that most "high-end" set-ups do tend to at least split the difference in the postioning of the pre-amp and mono-block components. Generally I have attributed this to "displaying" the amps rather than signal integrity. At least I know I'd be that vain about a pair of major mono-blocks...
EDIT: Thanks for the link... AA sems to have at least as good a handle on the topic as we do...
Were some interesting notes on components ability to "drive" a signal, not that it appplies here...
Tour...
Vox Copuli
Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb
"It's easy to get lost in price vs performance vs ego vs illusion." - doro
"There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
"Death doesn't come with a Uhaul." - Dennis Gardner
So, as long as everyone agrees with me there will be no problems...
They brought up some good points about the source components ability to drive a long cable length so as not to let the characteristics of the cable take over. Never thought of that one.
madmax
Avantgarde horns, 300b tubes, thats the kinda crap I want...
In any system noise cascades or is additive from each active circuit; therefore, all stages prior to the final gain stage should be protected from additional noise components.
For demonstration and ease of disscussion assume that 1.4V ~ 0dB.
Imagine if you will a noise spike of only .0875V across an interconnect between the preamp/amp stage. This noise is -12dB down from reference. Now apply a final gain stage of 24dB from our amplifier we have a noise gain of +12db which is actually 22.4V across our speaker. That very same .0875V noise spike, if not introduced within the active stage via the interconnect but is across the speaker itself, sees no gain from the amp and is really 36dB down istead of the 12dB from above.
I hope this makes sense and if not knock the hell out of me.
HBomb
madmax
Avantgarde horns, 300b tubes, thats the kinda crap I want...
Hmmmmmm...... I guess at a your 1/4 wave theory your safe to about 11,700 feet???? If I read this correct :rolleyes:
HBomb:D
Tour...
Vox Copuli
Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb
"It's easy to get lost in price vs performance vs ego vs illusion." - doro
"There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
"Death doesn't come with a Uhaul." - Dennis Gardner
We have outdoor speakers, with a 50 foot run to each speaker. We have pushed 200 watts in the Atrium 55 to get nothing but 95db (yes measured) -- (Yes, also on the amp, with the wattage meter). That should speak for itself.
"No, that's silly talk. Dude, you can't possibly be this audio dumb so quit the act." - Doro
I wonder how Sids atriums would fair in Denver @20k ft?
boy is this thread degening fast:D
HBpmb
First I'll have to find something to place between the wall and speakers. The 800i's are a few inches away from the wall. It wasn't a problem when I was listening at low levels though. It just felt pretty weird that I was facing an empty couch while listening:).
OK, I have another question. Do you think this amp is going to have any problems driving the 800i's? They're mono blocks and only cost $100 a piece.
http://www.divertech.com/aslwaveav8.htm
Maurice
Sorry, had to borrow this from Russ... then I looked and it's your thread so you can do wnat you want, I guess...
Tour...
Vox Copuli
Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb
"It's easy to get lost in price vs performance vs ego vs illusion." - doro
"There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
"Death doesn't come with a Uhaul." - Dennis Gardner
Good news and bad news on the Wave 8's. Those little monos sound great, and 8-10 w/ch is plenty for most casual listening apps. The only drawback I see with RT800's is the ported design of the speakers, and low damping factor of the amps.
Cool factor is through the roof though. How about getting four of em' and bi-amping? That, or step to the 20w model, or hell, get real crazy run a pair of 8's on the tweets, and 20's on the woofs...
Cheers,
Rooster
Russ,
I may just get the 20w model. I'll have to keep listening and play around with placement with the 800i's first. If I feel that I need a tube amp, I'll get them. I only thought about those Wave 8's because they're so dang cheap. Very cool idea about bi amping with the 8's and 20's. Thanks
Maurice
Why the damping factor concern? Bass control?
organ,
I have no idea any more on when to get concerned about a tube amp's rating. I've come to look more at their power consumption than their output...
Back on Sid's drop in...
Sid,
A little apples and oranges here. Outdoor, anechoic measurement of speaker output is not going to impress. At least not Atriums (VOT's another matter).
If you want to complete the test, compare the measured output of the amp with the input at the speaker terminals. You're not going to see that much difference.
Tour...
Vox Copuli
Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb
"It's easy to get lost in price vs performance vs ego vs illusion." - doro
"There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
"Death doesn't come with a Uhaul." - Dennis Gardner
Ed Zachry.
Cheers,
Rooster
Not into RF Hbomb? What type of engineering do you do?
madmax
Avantgarde horns, 300b tubes, thats the kinda crap I want...
That's very interesting. I've yet to max out the Dynaco's 35w/ch but the 8 watts on the Wave-8's does seem very little. Maybe I'll try them out and if they don't provide enough juice, I'll do what Russman suggested by bi-amping with the 20's on the woofers.
Maurice
35 wpc continuous
80 wpc peak
Power Consumption 190 W
I actually believe the 80 wpc peak is conservative.
Tour...
Vox Copuli
Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb
"It's easy to get lost in price vs performance vs ego vs illusion." - doro
"There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
"Death doesn't come with a Uhaul." - Dennis Gardner
So does anyone know why the Dynaco ST70 is rated at 35 wpc while some other amps using the same four EL-34's are rated at 50 wpc? The only real difference I see is that the Dynaco uses a rectifier tube whereas the other ones I've seen use diodes. (who came up with the idea of using cheap sand diodes in tube amps anyway?)
madmax
Avantgarde horns, 300b tubes, thats the kinda crap I want...
The ST-70 is a push-pull amp and it was designed to drive the EL-34's to 65% of it's power.
Maurice
I have been an wireless RF Engineer since the early 90's and a radar guy before that; however, that does not say I'm an audio expert. I have learned a bunch right here and have a long way to go.
I have not hooked my computer up in my new place yet so no evening surfing for me yet. Sorry for the late re-entry.
Back to the long interconnets though. The other consideration that has not been discussed is if we put the Dac and amps at the speaker and keep the transport at some remote location. Depending on the lenth of the 75 Ohm connection will determine your losses (which are very high for pcm) and as the line increases you will suffer from additional jitter. I would be very concerned about this and would say that the quality of the shielding will be the governing force of accurate digital to analog conversion. Even balanced xlr have line limitations and are a consideration for laying out a professional recording or broadcast stations. I believe AES3or5 actually calls these specification out as a guidline but the document is not very laymen oriented.
HBomb
My $.02:
How far are we talking? I've always been taught that the shorter the speaker cables the better. Same for ICs, but not to the same degree. I've also read that if you have long IC runs, use 75 ohm (ie video, digital or some sub)
Either way, if your runs are less than 30ft or so you should be fine.
Psst: I'm thinking of trying twisted strands of magnet wire on the VOTTs. Don't tell anyone though.
I thought I had heard that somewhere. So where did you come up with 11,700 feet?
So where do I get one of these DAC's for my turntable
madmax
Avantgarde horns, 300b tubes, thats the kinda crap I want...