RTi-A9 hook up

Igoggsy

Hi Everyone,

I picked up a pair of these during the future shop sal e(couldn't resist) and while I await their arrival, I am trying to figure what I need to adjust (if anything) in my current setup. I have an Arcam fmjA18 integrated amp rated at 50wpc running into KEF q50's from about 20 years ago. The KEF's are being replaced by the A9's and I am worried about power. The room is 10x24 so not huge by any stretch and I listen at low to moderate levels due to napping kids and the fact that I like my neighbors. Will the Arcam suffice? If not, I have an old nakamichi av receiver with main in's that I am pretty sure I cold hook up and use the Arcam as a pre amp.

Any help would be much appreciated!

Cheers

F1nut

Neither of your choices will get those speakers out of first gear. Time to go shopping.

tonyb

Your choices maybe ok for low volume listening, but then why buy big floorstanders if you can't let them rip every so often. If you do let them rip on your choices of power, your risk of frying a tweeter or 2 will go up greatly so keep that in mind. Yep, time to go shopping.

Igoggsy

Thanks all. Pretty much what I was presuming. Time to start researching.

Cheers

62caddy

I'm going to go out on a limb here and respectfully disagree. The RTiA9 has efficiency rating of 90db/1w/1m. The OP listens at low to moderate levels. 10 watts alone will be good for 100 dB which is probably far louder than he'll ever listen. I had used a 40 watt Proton receiver with 90 dB speakers for 20 years without the slightest difficulty, and on numerous occasions played loud enough to all but crack the plaster. To the OP: I suggest before running out and spending more money that you first try your new speakers with your present amp and then you will be in the ideal position to decide if additional investment in amplification is warranted.

Igoggsy

62caddy wrote: »

I'm going to go out on a limb here and respectfully disagree. The RTiA9 has efficiency rating of 90db/1w/1m. The OP listens at low to moderate levels. 10 watts alone will be good for 100 dB which is probably far louder than he'll ever listen. I had used a 40 watt Proton receiver with 90 dB speakers for 20 years without the slightest difficulty, and on numerous occasions played loud enough to all but crack the plaster. To the OP: I suggest before running out and spending more money that you first try your new speakers with your present amp and then you will be in the ideal position to decide if additional investment in amplification is warranted.

Thanks 62caddy! I was going to test it out in a couple configurations first so your post is definitely encouraging! With any luck they'll arrive today and I'll ring in the new year with them!

Sherardp

Suggest you ring it in at low volumes or else those bad boys may end up fried. I agree with F1, put an amp to those bad boys and then watch how they shine. Check out www.audiogon.com


http://www.audiogon.com/cgi-bin/cls.pl?ampsmult&1330133767&/Sunfire-Cinema-Grand-200x5

michael1947

Hi there, where did you say you purchased your A9's. I also plan on some of these large bad boys and plan on bi amping them with an old Onk avr with about a 110 wpc for the upper section then an old Kenwood with 150wpc for the lower section. Both amps are running at least 5 amps with large transformers. Any thoughts from anyone.

michael1947

Please excuse me from not noticing your number of posts...3. Welcome to the forum. I have been here for about a year and am now up to about 18 posts, not very many as I mostly read, it's much faster. I wish I could find out how to navigate around this site without stepping on toes, maybe there is a new-be group for us.

62caddy

Generally speaking most recommend using the same amplifier for both stages of speaker inputs. However no harm will be done in making the connections as you propose; try it and see.

tonyb

62caddy wrote: »

I'm going to go out on a limb here and respectfully disagree. The RTiA9 has efficiency rating of 90db/1w/1m. The OP listens at low to moderate levels. 10 watts alone will be good for 100 dB which is probably far louder than he'll ever listen. I had used a 40 watt Proton receiver with 90 dB speakers for 20 years without the slightest difficulty, and on numerous occasions played loud enough to all but crack the plaster. To the OP: I suggest before running out and spending more money that you first try your new speakers with your present amp and then you will be in the ideal position to decide if additional investment in amplification is warranted.

On bookies or small floorstanders in 2 channel that maybe ok. The 9's are big boys though. It's not about watts but current. Usually the scenario goes someone buys big floorstanders and under powers them. The next post usually is something along the lines of, "My speakers sound like crap", or "They sound terrible when I turn up the volume" or " No sound from my tweeter". It's your money, do what you will, but take it from hundreds of people here who actualy own those speakers or other Polk big boys, your going to need some juice to wake those 9's up.

My floorstanders are 95% efficient, wouldn't dream of feeding them from a receiver. You need some current to excert some control over all those woofers.

cfrizz

Welcome to Club Polk!

I agree with the others about needing more power to have the speakers operate to their full potential no matter where the volume knob is.

Since your intergrated amp has preouts, I would suggest getting this amp, and hearing what your new speakers are truly capable of.

http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1328117916&/B-K-Ref-2220-Big-bang-for-the-

tonyb

michael1947 wrote: »

Hi there, where did you say you purchased your A9's. I also plan on some of these large bad boys and plan on bi amping them with an old Onk avr with about a 110 wpc for the upper section then an old Kenwood with 150wpc for the lower section. Both amps are running at least 5 amps with large transformers. Any thoughts from anyone.

The down side of that idea is that by using 2 different amps, you will have 2 different sounds, 2 different speeds in the top and bottom portion of the speaker. While it will work, it may sound funky. Your sure free to give it a whirl though.

We get alot of questions here regarding powering speakers, bi-amping, it would only benefit you to read up some of the other posts we have by using the search function at the top.

62caddy

tonyb wrote: »

On bookies or small floorstanders in 2 channel that maybe ok. The 9's are big boys though. It's not about watts but current. Usually the scenario goes someone buys big floorstanders and under powers them. The next post usually is something along the lines of, "My speakers sound like crap", or "They sound terrible when I turn up the volume" or " No sound from my tweeter". It's your money, do what you will, but take it from hundreds of people here who actualy own those speakers or other Polk big boys, your going to need some juice to wake those 9's up.

My floorstanders are 95% efficient, wouldn't dream of feeding them from a receiver. You need some current to excert some control over all those woofers.

The 90dB speakers in my example were largish Boston Acoustics T1000 floorstanding towers w/dual 8" woofer, 5" mid and 1" tweeter compliment. 10 clean watts is the same whether supplied by a 50, 100 or 500 watt amp. The additional power is primarily for handling dynamic range. There are many who drive Klipshhorns with megabuck 12 watt tube amps which would be the roughly the equivalent of a 120 watt amp used with the A9s. Naturally more power would be necessary in order for the Polks in order to achieve their "maximum potential" however given the OP's listening habits, 50 watts should more than suffice. (IMHO)

tonyb

Your mistaking watts for current, different speaker designs dictate what current is needed. You can't compare speakers simply by going on how efficient they are.

Igoggsy

michael1947 wrote: »

Hi there, where did you say you purchased your A9's. I also plan on some of these large bad boys and plan on bi amping them with an old Onk avr with about a 110 wpc for the upper section then an old Kenwood with 150wpc for the lower section. Both amps are running at least 5 amps with large transformers. Any thoughts from anyone.

I bought them at Future Shop in Toronto (online actually). I think they are currently sold out after boxing day. Good luck!

62caddy

In another forum I posed the question of current and the following quotes are excerpted from that post.

"Ohm's Law defines the basic relationship of voltage current and resistance. How much current is enough is whatever it takes to satisy Ohm's Law. In fact that's all the current that can ever be. You can't force more current into a curcuit than what Ohm's Law defines."

"If amp A and amp B are both delivering the same amount of power into a given speaker, they are delivering the same amount of current."

Here is a link to the full discussion. http://www.audiokarma.org/forums/showthread.php?p=5274145#post5274145

F1nut

62caddy, have you ever heard the 9's on a low wpc amp verses a high wpc amp at low volume? I have and can say that without a doubt that they perform much better on a high wpc amp at low volume.

"If amp A and amp B are both delivering the same amount of power into a given speaker, they are delivering the same amount of current."

That's way too generalized. It doesn't take into account that amp A with a lower peak to peak amps rating simply runs out of gas when pushed (think transients) while amp B with a higher peak to peak amp rating doesn't break a sweat.

62caddy

F1nut wrote: »

62caddy, have you ever heard the 9's on a low wpc amp verses a high wpc amp at low volume? I have and can say that without a doubt that they perform much better on a high wpc amp at low volume.



That's way too generalized. It doesn't take into account that amp A with a lower peak to peak amps rating simply runs out of gas when pushed (think transients) while amp B with a higher peak to peak amp rating doesn't break a sweat.

There is no peak to peak change in current at a given resistance. There is a difference in peak to peak voltage (power) as defined by the specification limits of the amplifier. You are correct in one area- that current matters but that is related to driving low resistance loads- Ie: 4 ohm or less. An amplifier should theoretically be able to deliver double the amount power into 4 ohms than into 8 but in the real world there very few that have this capability. The A9s rating of 8 ohm should not pose any issue to the vast majority of equipment.

I cannot comment on the differences you claim to have heard between various amplifiers played at similar low output levels. Different equipment can sound differently. However I feel it is pure folly to assume vast amounts of power is prerequisite for quality sound. There are some excellently designed low power amplifiers as well as high power amplifiers that are very poorly designed. All I can say is that according to the laws of the physical properties of electricity, there simply no way to get higher current from x watts into x ohms- and any differences you experienced cannot have occurred due to the current factor.

Again, high power is critical for peak transients - especially when the average signal is played loudly enough- 1000 watts could be insufficient theoretically. Given the OP's listening levels are relatively low, probably utilizing an average of .05 watt (which would be 77 dB at 1 meter on the A9s) or less, it's inconceivable (to me at any rate) why he'd need any more power than he has now. In any case, he can always upgrade in the future as he sees fit. I never told him specifically not to invest in extra amplification; rather I advised to first try using his present unit first before making that committment. That's all I suggested.

tonyb

F1nut wrote: »

62caddy, have you ever heard the 9's on a low wpc amp verses a high wpc amp at low volume? I have and can say that without a doubt that they perform much better on a high wpc amp at low volume.



That's way too generalized. It doesn't take into account that amp A with a lower peak to peak amps rating simply runs out of gas when pushed (think transients) while amp B with a higher peak to peak amp rating doesn't break a sweat.

No substitute for experience.
Look guys, you can read all you want about this on the internet, Ohms law, blah,blah,and a host of other articles that will leave you more confused than before you started. You have to try different things, get some experience under your belt, don't be afraid to experiment. What works for one will not necessarily work for all. Here at Club Polk we have a wealth of knowledge from all aspects of audio and video from members with tons of experience. If you seek advice, your in the right place, if you seek opinion, your also in the right place. Never a shortage of opinion, thats for sure.

62Caddy, I have a feeling if you threw an amp on those Bostons, you might understand better.

Igoggsy

Guys- thanks for all the replies and healthy discussion. Definite food for thought- and even before the speakers have even arrived!!

When they do, I'll be sure to check back in and give you my impressions.

Cheers

Ian

62caddy

tonyb wrote: »

62Caddy, I have a feeling if you threw an amp on those Bostons, you might understand better.

I have. I used the Bostons and my RTiA7s with my Proton D940 40 watt receiver, a McIntosh 100 watt receiver, a Mc 2505 50 watt amp and an Mc 2125 120 watt amp. There was no appreciable difference with each amp driven within its limitations- in fact the "Low EQ" on the lowly Proton unit (a 10dB boost @ 75Hz) would practically throw the woofers across the room if set free with some material.

Look at the size of Khorns. There are those who run them on 12-20 watt big-buck tube amps.

Enjoyable discussion all the same! If everyone thought alike, the world would be a boring place.

tonyb

Sure, like I said, it's not about watts, but current and a tube amp in general delivers more current. Hard to compare a tube amp to solid state. Add in speaker design, and whats needed for power will vary. You can have 2 speakers both with an efficiency rating of 90, and because of speaker design, one can be 8 ohm and the other 4 ohm. The 4 ohm being harder to drive. That doesn't mean an 8 ohm speaker is a piece of cake to drive either. The more drivers in general, the more power is needed to move those woofers in and out. Such is the case with the 9's. At lower volumes, sure, the OP will be fine but like I said, you don't get big speakers if you don't want to let them run wild every so often......and thats where some run into problems blowing tweeters. We all have natural born instincts to test the limits of everything we own. Simply put, there is a certain amount of risk to under powering big speakers, people need to know those risks before hand, thats all I'm saying. Everyone is certainly free to do as they wish.

F1nut

The A9s rating of 8 ohm should not pose any issue to the vast majority of equipment.

A perfect example of theory verses reality. Theory lost this one.

kuznagi

On a related note, I will be expecting some RTIa9's from the same deal as well. I have an Onkyo 809 and will be expecting an Emotiva XPA-3 later in the month.

Just wondering in terms of setup when you configure the speaker in Hz, should I keep it as large speaker to get more bass (but drawing more power) or keep it at 80-100 hz

I have 2 subs, generic onkyo Side surrounds, csia6 and fxi a4s. What is the general Hz i should set each speaker to (this is before I get an emotiva)

Thanks!

Tour2ma

^ Welcome... but not really related and best asked in the Sub Hookup area of the Forum. Also, trust me, you really do not want to get into an Emotiva discussion here...

That said...
For 2-ch go "large" and lose the subs. For HT go "small" and while a full blown calibration is best, you can initially cross to your subs at 100 Hz and move down in 5 Hz increments until you stop hearing an overall improvement in bass response.

Now back to our regularly scheduled program...

kuznagi

Ooh haha oops saw the first post but didn't see the forum title

For the home theater option does that assume I have my entire system (7.2) active? So for the fronts I'll start at 100 Hz and keep going down? I will run Audyssey first and go from there.

Thanks!

sidsingh

I just bought a Harmon Kardon AVR3600 to replace my old AVR235, and am also waiting for my new A9's. Can I use use the old unit and a second amp to power the new A9's or will the the new 3600 be enough? I have a 7.2 setup currently with JBL s 310 as rears and athena asf2 for fronts and JBL Northridge bookshelf for rear surround. Thanks for help.

michael1947

For tonyb, 62caddy and f1nut...Thanks, you guys seem to have watts of answers. So my plan to run my new A9's with my Onkyo txnr 708 for the top section (110wps) and my Kenwood 208 (150wpc) via the pre-outs in the onk for the base section is a bad plan. Where do you get the "juice" reading in the specs of an amp/avr. My combo would put 260 wpc to the A9's and the Kenwood has 3db of headroom and I think the onk close so combined the could deliver 500 wpc. Annother issue is: someone said you usually bi-amp with the same amp.....I'm thinking that would be "bi-wire" and I am probably wrong. so...My thought is that you use 2 independent power sources, the avr acting as a pre for the amp then you could draw power from each up to their maxim limits during peaks and provide cleaner power even though it may be sonically different. I can't seem to find a bottom line here so let me do one more. I buy a nice emoltiva for $600 and it outputs 225 or 250wpc it would be about the same as my set-up. I'm not even sure what my questions are at this point. OK, here is a straight question: When Mathew and the boys build us a speaker and put the sticker on the back and it says:50-500 wpc do they mean 500 straight watts or including headroom. I look at the gear of many polkies here and see they are not even close to 500 wpc as they are mostly using stuff in the 200 - 250 area. Maybe the common thought thought is "that's enough" prevails so the real question is do I want to find a 500 wpc animal or stay in the common area of 225wpc. thanks, Michael

tonyb

You can use 500 watts if you want to, you won't harm anything. Do you need that much though to make those speakers sing ? Nope. Amps come in all different flavors and the 9's are harder to drive than the rest of the rti line up, but not that hard to warrant 500 watts imho anyway.

Usualy on any given receiver, you can only use one or the other, preouts or speaker connections, not both. Also using 2 different amps, or 2 different receivers on one speaker may sound funky because they won't have the same power, speed, or sound signature. Your certainly free to try it though and see if you like it.

If it was me, I'd just use the amp for the 9's from the front preouts of the receiver straight up.

michael1947

So, as long as there is no one on this thread right now I will ask a follow up...kind of like the debates. Is it possible to hook up two auxiliary amps. Maybe use a Y splitter on the pre-out and then one set to one of my Kenwood 208's and one set to my other identical amp. I have about 4 of them, not sure why. Then from say amp number 1 I run the left channel to speaker 1 and the right speaker 2 both in the high position of the speaker. From amp number 2 I run the right channel to speaker 1 and the left channel to speaker 2 both in the low base section. Will the onkyo txnr 708 have enough pre-amp capability to run both. I believe I am attempting to run with the gear that I already own and not make another purchase. Thanks