Crown XLS 1502 - is it enough to power RTiA9s?

pitdogg2

Nightfall wrote: »

Is waterboarding on the table or?

I prefer "Moisture Therapy"

mhardy6647

pitdogg2 wrote: »

Nightfall wrote: »

Is waterboarding on the table or?

I prefer "Moisture Therapy"

That's another thread, you silly lad...
https://forum.polkaudio.com/discussion/187532/my-kid-is-nuts

jruder

First time poster on here (but been reading for a while now)
Just sharing *my* experience, take it for what it is worth.
I installed night club and restaurant/bar sound systems for a living for quite a while (along with club lighting, but that is another story).
So when it came time to build my HT I assumed I knew exactly what I wanted.

My front speakers are RTi-12's.
Center is CSI-5 (powered by a crown xls 1000 bridged to mono)
Surrounds are all Bose 301's that I had purchased for a install that wound up not needing them.
Subs are 2 JBL 18's powered by about 1200 watts of crown power as well.
Decent Onkyo for its preamp outs.

Powered the RTI-12 (close to your 9's) with a Crown CSI-2000.

Overall?
Well, everybody here probably knows the answer:
Thundering base (duh).
loud sound and I thought it sounded great.

Then my HT flooded ruining my screen and I have not used it in about 6 months.

Our living room got upgraded to a very nice 70" 4k
But all I had was another crown xls-1000 being driven directly from the TV output hooked up to a pair of RTi-8's and a decent 12" powered sub (Klipsch).

Well, long story short (a bit late....sorry) I had a *small* budget to spend on upgrading the living room and purchased an open box Sony STR-DN1080.

Drug the RTi 12's and CSi 5 upstairs, moved the RTi 8's to the rear for surround sound.
Biamped the 12's just using the Sony.
No external amp at all.

Result?

Not as much base as downstairs (well...2 18s? A little stupid, but fun for watching trance and filling room with smoke and and lasers!)

But over all sound?

Better.
Cleaner, and sounds louder in my subjective opinion.

Been going back and re-watching movies all weekend (this just happened).
I am truly surprised at how much sound and features I got for a less than 400.00 purchase (the sony was 380.00).

Anyway...just my two cents. Pro amps just don't cut it in a HT setup from what I have experienced.
I am sure there are people on here who would rather pull their eyebrows off than listen to a setup that is *only* driven by a Sony DN1080 -- but I could not be happier for the money spent.

Now, also realize that I only have 5.1 due to giving up my surround height amp section to drive the top section of the Polk RTi 12's...at some point down the road I plan on redoing this but right now I am enjoying the upgrade from 'pro' to 'normal' gear!

FestYboy

You also aren't bi-amping the 12s with the Sony... Just gonna throw that out there before a certain someone else catches it.

pawelmwo

I really like the Outlaw 2200 Monoblocks. They are very slim profile and run cool to the touch. I have no issues driving my Polk 705's at reference levels cant note any audible distortion. I got a pair for $100 bucks used

tophatjohnny

What a "Tool" thread this is going to be. How bout dat nu album🎩

jruder

LOL....I was wondering how long that would take!

@FestYboy -- and why is that?

By definition bi-amping does not have to mean actual separate external amps with separate power supplies. Although that would be better. At least as far as I know and understand.

They are two separate amplifier circuits inside the receiver -- what would you consider this if not bi-amping?

rooftop59

jruder wrote: »

LOL....I was wondering how long that would take!

@FestYboy -- and why is that?

By definition bi-amping does not have to mean actual separate external amps with separate power supplies. Although that would be better. At least as far as I know and understand.

They are two separate amplifier circuits inside the receiver -- what would you consider this if not bi-amping?

One power supply that drops like a tank when you add extra speakers. So, one channel might be 120 wpc, 2 channels 100, 5-7 channels usually drops to about 35-40 wpc. Look at professional bench tests on Best Buy mass market receivers. So, what are you adding besides speaker wire? And feeding more power to the tweeter than it needs while robbing the power hungry drivers...

mhardy6647

Well, there are some firmly held opinions on the topic of what biamping is -- which I find sort of amusing, even though I am largely in sync with the prevailing opinions on the topic around here

I will take this opportunity to mention one potential advantage of using a multichannel device to "biamp" that probably hasn't often been broached here (if I may ).

Loudspeaker crossover networks are evil, evil things. They require expensive components "for best results" and they are, electrically speaking, profoundly inefficient circuits. Much of the power provided to a loudspeaker is lost as heat simply due to the need to push the signal through the crossover network. This requires the components of loudspeaker crossovers (especially in low sensitivity, low impedance, power hungry loudspeakers to be very beefy (i.e., to be able to handle prodigious amounts of power). Indeed, it not uncommon to see crossover damage (cooked components!) caused by excessive heat... that heat comes from the amplifier power being dissipated by the loudspeaker load.

Is this a good thing? Arguably, no

Of course, one other approach to the "problem" of dividing the signal (music!) into different frequency bands and delivering them to the various drivers in a "multi-way" loudspeaker system is to do the "crossing over" at low signal level (line level). The components don't have to sink a lot of power (i.e., better quality components that are cheaper can be used due to lower power requirements), the signal is "tailored" to the
speaker driver (and cabling) and the amplifier used can be optimized to the frequency band being used.

There was a brief fad (at least in Japan) of amplifiers and receivers with built in crossovers and multiple amp sections to deliver H/M/L signals to speaker systems that had no XOs in them. Here's an example (a late 1960s - early '70s Onkyo) -- of course, there was a specific Onkyo 3-way speaker system (sans XO) designed to be used with these.




Nowadays, DSP allows the development of pretty sophisticated line-level "frequency dividing networks", including contouring and time-alignment, using just software. The boxes that can do this are surprisingly affordable*, too.

Now, the point of this little sermonette, simply put, is that line-level XOs can be logically and rationally paired with a single multichanneled amp (and, of course, crossoverless, multiway loudspeakers). Is it the 'best practice' for 'biamplification'? Well... no... but there is a case to be made for the approach.

______________
* Here's a nice, affordable, configurable DSP option, e.g.
https://www.parts-express.com/dayton-audio-dsp-408-4x8-dsp-digital-signal-processor-for-home-and-car-audio--230-500

tonyb

In more layman's terms, think of current as Horsepower in the car world. You can find many smaller engines with boat loads of horsepower and some larger engines with not so much.

Current is measured in "amperes peak to peak" on an amps spec sheet. The speakers you have a fairly power hungry so an amp with a good amount of current is going to be needed to get them to perform their best. No receiver alone has the grunt. You also want an amp that is a tad on the warmer sounding side to offset the naturally brighter sounding characteristic of the speakers. You should also choose your cabling in the same manner, tad warmer.

Pay little attention to the watts per channel thing. Quality and current come first, as already stated. You can also do a search, top right hand side, for more on the subject as your not the first one to ask about power and RTI speakers.

jruder

Thanks @mhardy6647 and @tonyb
Very interesting.

And, yes, I agree that 'true' bi-amping is always way ahead of what I am doing.

But I am 100% sure that I think I might positively hear a difference in doing it this way perhaps!

I did a A/B test but there was about 30 mins. in between them while I switched everything over -- so it could just be placebo.

I am all for doing 'real' bi-amping but I have not been able to find a decent affordable receiver with separate outs -- I know, you get what you pay for.
But hey...car payments, rent, vacations etc just keep sucking up the funds.

And it is hard to argue that I need to spend twice as much money when the system sounds this good already.

So, one (two) serious question -- @rooftop59 :
1. how much power *should* the tweeter/highs be fed?
2. How is this in anyway robbing the woofer anymore than just plugging it into one channel and letting the crossover in the speaker do its thing?

Also, I have wondered, on the speaker when you bi-amp is it just sending all the top end directly to the tweeter or does it get split up between the mids/highs while all the low goes to the woofers?

I am not trying to start a war over this, just looking for real information for my learnin'

mhardy6647

It all boils down to Ohm's Law. Basic understanding of Ohm's Law will set the naive audiophile free from a lot of marketing hyperbole




This is very simple stuff to understand and to master if one is so disposed. "Resistance" is the DC analog of AC "Impedance". Impedance also obeys Ohm's Law, but varies with frequency (which, frankly, is where all the trouble starts with hifi in general and boutique hifi in particular ).



Not all loudspeakers require grunt -- although current (heh, no pun intended) fashion in loudspeaker design results in myriad speakers that do (cf. my little crossover screed above).

The problem with gruntless amps (and many of the grunt-enabled ones, IMO) is that they lack the finesse (quality, per @tonyB's post above) to deliver good sound at low power levels. That's been a problem with massmarket components since the advent of decent quality transistors made power available cheaply (mid-1960s).

jruder

did a search for "powering RTI'
Currently reading the plethora of articles and posts on it.

Thanks...

Joe

FestYboy

@tonyb I like to use torque as the analog for current, as that's where all the work gets done. Hp, as you know, is just a derived number, and like watts, carries little real meaning or value.

Geoff4rfc

@FestYboy I can dig the torque analogy.

In '05 I ran the Suz 750 with 132hp. It got down Portland's straight pretty fast reaching a top speed of 175mph.

The following year I was on the Suz 1000 (pictured). It was equipped with 164hp and got down Portland's straight with a top speed of 185mph....but....even though it was just over 30hp more, the difference in torque was ungodly as this thing tried to spit me off the back of it with every shift of the 6 speed tranny up until I stabbed the front brake lever for turn one.

I was literally doing pull ups all the way down the front straight just trying to hang on. I learned a lot that year as that was my first liter bike from 15 years of competition.

I hate doing pull ups in the gym but I was forced to add that to my routine as that one exercise made all the difference out on the track. Torque is brute force power that comes from down below that will bend steel bars in half!!!!

jruder

that is bad **** @Geoff4rfc !

I still have an open question after much reading of how much power to feed the high end vs the low end?

It looks like when you bi-amp the RTi-12s that you do feed the tweeter alone then all the other speakers together.

It seems like every amplifier I look at feeds something like 100 watts to 4 channels or 200 watts each to 5 channels.
It would seem like 50 x 2 plus a 200 x 2 would be a good match.

Otherwise it just seems like a LOT of juice for just a tweeter.

I fried one of these tweets already and had to replace it a while back, I don't want to have to do that again as they seem to be getting hard to find.

Yesterday the wife left so I got to really put it through its paces and I hit that sad place of "That's all there is??" on the volume control... "

So....now looking to sell some other AV gear to 'justify' the (obviously) much needed upgrade!

I have a 2 week or so return window on the Sony receiver but whatever I replace it with needs to come from Best Buy ( I used some store credits to help purchase it).
I have a max price range of around 500.00 just for the receiver, then I can slowly add amps down the road.

Advice would be appreciated.

F1nut

You fried the tweeter because your AVR or whatever ran out of guts and sent a clipped signal.

Forget about bi-amping, it's not what you think it is.

I hit that sad place of "That's all there is??" on the volume control...

You will continue to hit that place. A 3dB increase in volume requires double the power and that adds up quickly.

Instead of trying to blow out your ear drums aim for quality sound.

jruder

Not trying to blow out my ear drums, and I agree that quality sound is the goal.

I am considering the Marantz SR6013 - they have a open box one at Best Buy for 674.00 (about 200.00 more than I paid for the Sony).

I am fine with moving past bi-amping, I was more looking at external amps vs internal.

Although I am thinking that with that particular Marantz it may be beefy enough to keep me happy for quite a while. Then down the road if I want to I can add an external amplifier.

tonyb

FestYboy wrote: »

@tonyb I like to use torque as the analog for current, as that's where all the work gets done. Hp, as you know, is just a derived number, and like watts, carries little real meaning or value.

FestYboy wrote: »

@tonyb I like to use torque as the analog for current, as that's where all the work gets done. Hp, as you know, is just a derived number, and like watts, carries little real meaning or value.

LOL, I hear ya. My analogy was really about Horsepower and cubic inches. Like a 350 or 455 ci car engine. Same point though.

tonyb

jruder wrote: »

Not trying to blow out my ear drums, and I agree that quality sound is the goal.

I am considering the Marantz SR6013 - they have a open box one at Best Buy for 674.00 (about 200.00 more than I paid for the Sony).

I am fine with moving past bi-amping, I was more looking at external amps vs internal.

Although I am thinking that with that particular Marantz it may be beefy enough to keep me happy for quite a while. Then down the road if I want to I can add an external amplifier.

Will your speakers work on just that receiver ? Sure they will, but I wouldn't go crazy on the volume dial, that's when trouble will start for you.

Get an amp down the road, that's cool, just be careful of the volume is all, don't push it.

rooftop59

tonyb wrote: »

jruder wrote: »

Not trying to blow out my ear drums, and I agree that quality sound is the goal.

I am considering the Marantz SR6013 - they have a open box one at Best Buy for 674.00 (about 200.00 more than I paid for the Sony).

I am fine with moving past bi-amping, I was more looking at external amps vs internal.

Although I am thinking that with that particular Marantz it may be beefy enough to keep me happy for quite a while. Then down the road if I want to I can add an external amplifier.

Will your speakers work on just that receiver ? Sure they will, but I wouldn't go crazy on the volume dial, that's when trouble will start for you.

Get an amp down the road, that's cool, just be careful of the volume is all, don't push it.

That receiver just doesn't have enough amps to get all those bass drivers moving, but yes, it will work and the mids and highs will sound nice at medium volumes. But like Tony said, don't go crazy or you'll blow a tweet!

jruder

With that speaker then would I be better to feed the tweets with a smaller but dedicated amp and then a larger one for the base through bi-amping?

Or just let the internal cross over do its thing and feed them with a good quality stereo amp?

I am still at a loss as to how much power to send a tweeter vs the main portion of a speaker, it seems like every bi-amping setup I see sends them all the same which seems crazy to me.

mhardy6647

The treble energy content of music is almost always quite low relative to the bass and
midrange - and the amount of power required to amplify the treble is typically considerably less than for (especially) the bass.

That said, the sensitivity of the tweeter and the crossover will have profound impact on the actual amount of power required for treble amplification in any given amplification.

That said, it's pretty common to see biamped systems running a fraction of the amount of power for midrange (MR) and high frequency (HF) 'channels' compared to the low frequency (LF) 'channel'. The exact figures will vary substantially depending on the sensitivity of specific drivers*, but, as a very realistic example, one might use a 250 watt solid state amplifier to amplify LF for the woofer, and a 3 watt single-ended, direct heated triode vacuum tube amplifier to amplify MR and HF for the treble (one or two drivers, depending upon design). Some folks will opine that this can be a best of both worlds.

That said, as @F1nut mentioned, it's generally not possible (where most modern loudspeakers are concerned) to have too much power; clipping is a bad thing, full stop -- especially with solid state amplifiers, which clip (transition into nonlinearity) much less gracefully than do vacuum tube amps (but that's another story for another time ).

The real question is what is one trying to accomplish? So many things are important (size and 'condition' of the listening space, type of music listened to, desired listening level, type of loudspeakers used) that it's actually impossible to answer the "how much power do I need" question in the abstract.

Sorry

___________
* Driver sensitivity can vary tremendously. For example, The supertweeters I use are rated for ca. 105 dB SPL at a distance of 1 meter when driven by 1 watt of amplifier power. A Dukane "Ionovac" plasma tweeter (even though horn loaded) is about 35 dB less sensitive. 1 watt into one of my horn-loaded supertweeters would produce the same SPL as 3165 watts into an Ionovac!

rooftop59

jruder wrote: »

With that speaker then would I be better to feed the tweets with a smaller but dedicated amp and then a larger one for the base through bi-amping?

Or just let the internal cross over do its thing and feed them with a good quality stereo amp?

I am still at a loss as to how much power to send a tweeter vs the main portion of a speaker, it seems like every bi-amping setup I see sends them all the same which seems crazy to me.

In order to get the right volume from two different amps with different, I think you would need an active external crossover.

Just get one big-boy amp, 200 or more WPC, and call it a day. Something from B&K or Parasound would be great, as they are both warm to neutral, and you DON'T want bright with those speakers...

tonyb

Forget the bi-amp thing....for now anyway. The tweets are only going to use around 20 watts at best anyway.