Tubes and Subs.

[Guest Bendrx]

Hey all,

Just Recently got a decent little set up going. I've got an RSA-500 powering a RW-5101-C in ceiling sub and 2 KS-7502-THXs for left and right. For a center I've got a R-5800-W right now, but wanting a KL-6502-THX to replace it and possible get a second R-5800-W to use them as surrounds. Right now all the speakers as sitting on the floor waiting (but hooked up and bang'n) to be installed proper like. To give a point of ref, I've had the speakers for a few months but just got the sub up and running. Before that I was using a Best Buy brand reciever and headphones because the speakers that came with it were really bad. Until now the "Quality audio in my life" had been the stock sound in my car, so I may seem, and even be, overly excited and long winded. Also I'm going to be setting up 5.1 as implied above, but this is for music, I know the ceiling leaves much to be desired in a surround system. Typically my Yamaha is set to 5 ch Stereo and I doubt that will ever change, until it becomes an Onkyo set to 5 ch Stereo. So here are my questions, and any info would be appreciated:

1) Looking at Tube amps, they all see to be very "weak" but I've been reading people say that a 20 watt tube amp will power thier 200watt RMS pair of speakers so that they can be heard blocks away. I always considered a "Watt" to be a universal engergy unit and 1 watt of any power is equal to 1 watt of any other kind of power. I assume I'm confused here. I know that the sensitivity for mine are 91db per watt per meter, and with that being said 20 watts would be alot, but I've got a feeling that 1 watt of power from a 5 X 100 amp that's in the Yamaha isn't going to give me 91db standing 3 feet from the speaker. Am I crazy, and anyone know of a good site that explains such things on a moderately technical level without going into an Engineering degree? The reason I'm looking into this is I've heard really good things about the "warmth" of sound from tube amps, and was interested. I've seen some and they aren't cheap, so may not be worth it anyways. I myself have never heard one in use, but would still like to know what's up with the Watts.

2) I've found info on sub placement for everywhere but the ceiling. It's my understanding that with good bass in the front you can put it pretty much anywhere, but will little to no bass up front you want them in the front 1/3rd of the room. With mine sitting on it's side in my soon to be listening room the air vibrates just about anywhere in the house so I assume I should just put it wherever I want. Being ceiling mount, once it's in, it's not moving. So basicly, I can put it anywere I want to right? Personally I'd like it near the center of the ceiling unless a corner would be better - but I assume not.

Sorry to be so long winded but I did give a warning, I've been looking through the forums here and on other sites, but havn't come across the info yet, still have more looking around to do here but when I searched for the RW-5101-C (which is an awsome little sub) I didn't get a single result so figured I'd just ask now. Thanks for taking the time to read this, and if you can provide an info or opinion I would appreciate it.

[Dylanl]

" I always considered a "Watt" to be a universal engergy unit and 1 watt of any power is equal to 1 watt of any other kind of power"

Well that is almost never true in newer receiver units. They tipically lie about output watts. Vintage is closer to specs. Is doesn't take a lot of watts to drive most any speaker but woofers/ mids need the power to make the transition easily without clipping. Look at your speakers SPL level and you will know if they are efficient or not.

Sry just rereading your post and I see that your speakers are 91db well they are not bad.

So...... What is a Watt? A watt is a unit of energy, like horsepower or joules. In audio, a watt is used to describe the energy output of a receiver or amplifier used to power a loudspeaker. The relationship between power output and speaker loudness or volume is not linear or straight (+10 watts does not equal +10 dB). For example, if you compare the maximum volume of a 50-watt amplifier with a 100-watt amplifier the difference is only 3 dB, barely greater than the ability of the human ear to hear the difference. It would take an amplifier with 10 times more power (500 watts!) to be perceived as being twice as loud (a +10 dB increase). Keep this in mind when purchasing an amplifier or receiver. 2X the power output = +3 dB increase, 10X the power output = +10 dB increase, or twice as loud.

[Oblio]

A Watt is a Watt. The difference is how much of the power is 'wasted' or lost due to resistive heat dissipation, mechanical losses, acoustical losses etc. When you add up ALL the losses and add it to the acoustical output you will get the input power.

[JohnA]

A watt IS a watt. Your ear will tolerate huge distortion from a tube amp and think it sounds good, bucause it is mostly even order harmonics. Because of that, people will overdrive tube amps to high *average* power levels with high disortion and lots of clipping and it WILL be as loud as a SS amp not driven into hard clipping.

[jheis]

The most important "link" in the audio chain is the choice of speakers.

While there are some excellent In-ceiling and in-wall speaker systems, "in-ceiling" is by far the most compromised placement for accurate sound reproduction.

No offense, but IMHO tube amplification for a in-ceiling system is lipstick on a pig.

[SWL]

tube amplification for a in-ceiling system is lipstick on a pig.

I once seen a pig wearing lipstick while he was pissing in the wind.......the wind wasn't at his back I might add.

[Dylanl]

tube amplification for a in-ceiling system is lipstick on a pig.

I once seen a pig wearing lipstick while he was pissing in the wind.......the wind wasn't at his back I might add.

Really,.... Where?

[CECAA850]

No offense, but IMHO tube amplification for a in-ceiling system is lipstick on a pig.

Nah, more like socks on a rooster.

[Pete H]

Or what if the pig with lipstick was pissing on the socks worn by a rooster that was down wind?

[Guest Bendrx]

I'm truly amazed at the quality of people on this forum; clearly there is no direct relation to the quality of the speakers and the listeners unless it is an inverse relationship. I do appreciate the info from the first couple posters in reassuring me that I wasn't crazy on watts = watts. Of if you want to put it 1 watt/s = 1 Joule = 1 watt/s. Anyways, as the pig commenter’s have seemingly missed, the reason behind interest in the tubes was for the distortion they provide. Therefore the basis of "ceiling mounts being as absurd as lipstick on a pig" is completely unfounded; the goal is simply a pleasant distortion as opposed to perfect reproduction. I fully agree that ceiling mount would not be idea for home theater or perfect sound reproduction, but as stated that was not a concern. This is a basic, and compared to many many many set ups here: cheap. Since I was never corrected about the "warmth" of sound, I will have to assume that I'm right. I take no offense to the original comment, I asked for opinion and that is what was provided. The farm obsession and complete lack of intelligence that followed is disturbing an akin to something I would expect to find on a honda forum. Anyways, this will be my final post on these forums.

[Romak]

My gracious.....tempermental fella.

[artto]

A watt is a watt.

However, any so-called “differences” between one amplifier
or another’s “watt” is usually determined by how the manufacturer measured it,
for specification (and advertising) purposes. Many things can affect power
output measurements such as distortion level, frequency bandwidth, power
response, how long the amplifier can sustain “full power” under the
aforementioned conditions, all channels operating or just one, etc.

Your RW-1501 requires use of the RSA-500 amplifier so here
the point is moot.

On the THX speakers you’ll most likely need a receiver that supports
some THX qualified format. Personally, I don’t know of any THX certified tube
amps/recievers. People usually use tube amps for music reproduction, not 5/7
channel setups with speakers primarily designed for movie sound (THX
certified).

As far as the lipstick on a pig comments are going ~
unfortunately they are correct. I don’t really see the point of using 5 or more
channels of tube amps. If you’ve “skimped” in the speaker department by using
small ceiling mount speakers I don’t think you’re going to realize any gain in
performance or audible improvement by using tube amps which tend to be
expensive, large, generate large amounts of heat, and are costly to maintain
and operate.

“Looking at Tube amps, they all see to be very
"weak" but I've been reading people say that a 20 watt tube amp will
power thier 200watt RMS pair of speakers so that they can be heard blocks away.”

True, but this is not because of the sound qualities of the 20
watt tube amp, it is because of the efficiency (sensitivity) of the speaker
being used, not because it’s a “200 watt RMS speaker” with a 20 watt tube amp.

Tube amps tend to “sound” louder. They typically have higher
levels of measured distortion. The distortion tends to make amplifiers “sound”
louder. They also have more “give” as they approach maximum output acting like
very natural compressors, unlike solid state which tend to simply play clean
until it clips the signal (ewoh!!!)

As far as sub placement goes, the same principals should apply.
Free space (1x) has the least amount of bass reinforcement. 1/2 space (an infinite
wall) is next best. ¼ space (a wall and floor or wall and ceiling) location is
next best. 1/8 space (two walls and the floor or ceiling corner) provides the
best overall support/reinforcement of low frequencies. Other issues may come
into play such as the geometry and size of the space as well as things in the
space which will affect the overall smoothness of output.

Since your priorities obviously required concealed appearance
and use of ceiling mount speakers as opposed to ~ dare I say “sound quality”, I
don’t think there is much, if anything to be gained from the use of tube gear
in a system such as yours.

[CECAA850]

Anyways, this will be my final post on these forums.

Don't go away mad.

[CECAA850]

Good post artto.

[russ69]

Bendrx,

Some of the posts took a sledge hammer approach to the question to make a point. The point was that your system won't benefit from the ideas you suggested. Wall mounted speakers are very limiting so it's had to come up with useful suggestions. Spend a little time here and you'll pick up some basic info that will help you in the future.

[Coytee]

The farm obsession and complete lack of intelligence that followed is disturbing an akin to something I would expect to find on a honda forum

Uh oh...I live on a farm and drive a Honda...[:^)]

[Coytee]

I'm just curious here...

Is it even fair to have some of these analogies (I'm talking about amps, not pigs, lips and roosters)

Isn't it more appropriate to talk about the number of volts an amp produces?

I harken back to my Jr. High School days when I took an electrical shop class... I seem to remember that watts was more a unit of dissapation of heat?

Something like, I have a 1,500 watt heater (which would put out more warmth than a 500 watt heater)

I would rather hold a bare, lit 40 watt bulb in my hand than a 350 watt bulb in my hand. Isn't the wattage rating on a speaker more in line with how much heat it can dissapate? Furthermore, isn't that heat generated by an input of volts?

You all discuss this, I've got to leave shortly & prepare the morning slop.

[&]

[Blvdre]

Power describes a relationship between voltage, current and resistance (or impedance, when it varies with frequency) P=IE, P=(E^2)/R, and P=(I^2)R. The musical waveform is seen as a varying voltage amplitude at the amps output. The rub is that the amp needs to supply enough current to keep the power from sagging, which can be a difficult task when presented with a low impedance load.

[Oblio]

I'm just curious here...

Is it even fair to have some of these analogies (I'm talking about amps, not pigs, lips and roosters)

Isn't it more appropriate to talk about the number of volts an amp produces?

I harken back to my Jr. High School days when I took an electrical shop class... I seem to remember that watts was more a unit of dissapation of heat?

Something like, I have a 1,500 watt heater (which would put out more warmth than a 500 watt heater)

I would rather hold a bare, lit 40 watt bulb in my hand than a 350 watt bulb in my hand. Isn't the wattage rating on a speaker more in line with how much heat it can dissapate? Furthermore, isn't that heat generated by an input of volts?

You all discuss this, I've got to leave shortly & prepare the morning slop.

Volts simply expresses the force of the current aka Electromotive Force (EMF) which is what causes the current to flow. It is the current that does the work, be it Electrodynamic (causing the voice coil to move in the magnetic field) or thermal (causing the coil to heat up).