Driving RTi10s

nm4710

Hey guys

Just got a pair of RTi10s...seems my HK245 receiver (50w/ch RMS 20Hz-20Khz) is not up to the task of driving them...the speakers have virtually no bass whatsoever (and yes, that's with the crossover off). If I crank the bass tone setting on the receiver up I can begin to hear what sounds like decent bass...but it's still soft.

I want to run an external amp to power these..and my receiver has pre-amp outputs. I've ordered a 100wpc onkyo (M-282) as an external amp - if I run this to the woofers alone, can I expect a substantial improvement in sound quality? I'm planning on using the HK's amp to drive the tweeters/midrange.

I'm trying to get the most out of my RTi10s...but I'm starting to wish I'd just gone for a pair of RTi6's because these things seem to be power hogs.

bsoko2

You need at least 200 wpc and that depends on how big yhour space is.

Bill

Kex

nm4710 wrote: »

Hey guys ...

Hey nm! Welcome to the forum!

I don't have any answers for your dilemma, but I am driving RT55s (same specifications, but different tweeters and/or crossovers to RT55i, I think) with a modest harman/kardon 147 (40 wpc, "all channels driven" marketing blurb, so maybe similar to 100 wpc claims by others ...? FWIW). The sound is really fabulous and I am very pleased indeed ... loving them a whole heap right now! I am a little surprised by the extent of the problems you describe with your RTi10s, but will watch the responses you get since I might consider something similar myself eventually too, to get the best out of the RT55.

RT55i: http://www.polkaudio.com/homeaudio/products/rt55i/

MADGSF

I would run whatever external amp you buy to the whole speaker not just the woofers. Reason being the tweeters hardly use any power at all.

Never heard the Onkyo M-282 and I don't see the current spec for that amp which your speakers need lots of. But any external amp would be an improvement. I am partial to B&K products with the RTi series speakers. Good used ones can be found on Audiogon and if you have the money that is the direction I would recommend.

Ron Temple

Welcome to Club Polk...try the Onk first, it's a nice amp and you should notice better bass, separation, detail and punch. Let us know how it sounds when you get setup and stick around...

cfrizz

Kex there is a big difference from your HK driving a pair of bookshelf speakers & having it try to drive these.

http://www.polkaudio.com/homeaudio/products/individual/floorstanding/rti10/

You would quickly find your HK running out of steam as well.

Kex wrote: »

Hey nm! Welcome to the forum!

I don't have any answers for your dilemma, but I am driving RT55s (same specifications, but different tweeters and/or crossovers to RT55i, I think) with a modest harman/kardon 147 (40 wpc, "all channels driven" marketing blurb, so maybe similar to 100 wpc claims by others ...? FWIW). The sound is really fabulous and I am very pleased indeed ... loving them a whole heap right now! I am a little surprised by the extent of the problems you describe with your RTi10s, but will watch the responses you get since I might consider something similar myself eventually too, to get the best out of the RT55.

RT55i: http://www.polkaudio.com/homeaudio/products/rt55i/

ben62670

I would look for an Adcom 2 channel amp to drive those. Your HK is a really good Pre for driving amps. I did it for a long time, and do not regret it. As for 200 watts yes that is a good reference for max output, but if you are looking for good solid sound there is a GFA-5300 for sale here really cheap. Do not be fooled by the 80 watt at 8 ohm rating.
My first Adcom was a GFA-5400 (130 at 8ohms), and there is no comparison to a receiver with the same rating. You can also search Ebay for a GFA-555 that puts out 200 at 8ohms. I also have a GFA-7500 for sale, but that is 5 channels x 150 watts at 8 Ohms ($600). Another amp to look at is Parasound. The Adcoms, and Parasound offer the best bang for buck amps IMHO.

Most of all welcome to Club Polk
Ben

psb962

I have just bought some RTi10s and I have a 75wpc amp - the Onkyo 502 - and I had some issues at first but things are improving now. It's certainly loud enough for my 16 x 12 HT room.

If you dont already have one I suggest getting a Radio Shack SPL meter and running some tests to see what you are actually getting in terms of frequency response across the woofer-thru-mid range at reference level.

The downloadable CD of test tones here:

http://www.realtraps.com/test-cd.htm

..really opened my eyes to what was going on when I used the meter. A lot depends on how the amp is configured, not just in terms of crossover frequency, but whether you have the fronts (or anything else) set to Large. The 502 also has a 'double bass' facility to send the bass to the sub as well as the fronts when they are set to Large.

To cut a long story short, in testing I found a 80-100Hz 'hole' in my response that I mitigated by running the amp with the 'double bass' on. So the sub is 'sharing the load' of the bass frequencies with the RTi10s and it seems to work much better.

Kex

cfrizz wrote: »

Kex there is a big difference from your HK driving a pair of bookshelf speakers & having it try to drive these. ...

Right, I understand that, in part at least! I'm interested in this topic because I'm wondering how much more I could get out of the RT55 (x4, + CS400 x1) if I added extra power. I'm guessing that an RTi8, for instance, might not be much harder to drive than an RT55 (with or without the "i"). Is that a correct assumption, or misguided? Is it because of the two woofers on the RTi10 that they are so significantly harder to drive, because they are larger 7" woofers, because there are three drivers instead of just two, or just the lower 20Hz frequency response (or something else entirely, of course)?
- RT55 = two 6.5" Mid/Woofers
- RTi10 = one 6.5" Mid/Woofer + two 7" Woofers

I also noticed that the RTi10 have 89dB efficiency compared to 91dB. I expect 4 ohm speakers to be hard to drive because, in theory at least, they require twice as much power from the amplifier, but not so much a larger 8 ohm speaker. What's the key to really needing extra amplification rather than just preferring extra amplification and will I be shocked by the added performance if I add amplification to RT55s?

Kex

psb962 wrote: »

... The 502 also has a 'double bass' facility to send the bass to the sub as well as the fronts when they are set to Large.

To cut a long story short, in testing I found a 80-100Hz 'hole' in my response that I mitigated by running the amp with the 'double bass' on. So the sub is 'sharing the load' of the bass frequencies with the RTi10s and it seems to work much better.

What settings are you using nm4710, for speaker size and in the subwoofer settings menu?

Is it not a bit odd for a speaker that has a lower -3dB limit of 35Hz to have a hole from 80 to 100Hz, or is this commonplace?

nm4710

Well I've tried running the RTis on all settings (large, crossover at 40/60/80hz)...regardless of the setting the bass seems very weak when compared to the midrange and treble. I have a Kef PSW3500 sub which augments it nicely, but I'd really like to make use of the woofers on the RTi10s (I did pay for them, after all).

I don't really see a hole..and honestly my SPL meter reads decent values all the way down to ~35Hz...but again the bass sounds very weak and the woofers barely have any noticeable output in the 70-80dB window I use for music and TV.

I'm also concerned that at >80dB my amp may be clipping a little (I hear some mild distortion..kind of a crackle with high pitched vocals)...so for that reason I've scaled my fronts back to "small" and set the crossover to 60Hz. I certainly can't crank these speakers above 85dB without getting audible distortion...and that's regardless of the crossover setting.

MillerLiteScott

You need and amp. Everything you are describing is indicates lack of power and impending damage to either speaker or AVR. If you want more bass you need MORE and QUALITY power. After I added an amp my RTi 10's put out enough bass that I did not need to use a sub.

Scott

Systems

nm4710 wrote: »

Hey guys

Just got a pair of RTi10s...seems my HK245 receiver (50w/ch RMS 20Hz-20Khz) is not up to the task of driving them...the speakers have virtually no bass whatsoever (and yes, that's with the crossover off). If I crank the bass tone setting on the receiver up I can begin to hear what sounds like decent bass...but it's still soft.

I want to run an external amp to power these..and my receiver has pre-amp outputs. I've ordered a 100wpc onkyo (M-282) as an external amp - if I run this to the woofers alone, can I expect a substantial improvement in sound quality? I'm planning on using the HK's amp to drive the tweeters/midrange.

I'm trying to get the most out of my RTi10s...but I'm starting to wish I'd just gone for a pair of RTi6's because these things seem to be power hogs.

I have an Onkyo M-282 running my set of Polk Atrium60's (outside). It should be able to handle your RTi10's just fine. I have Rti12's and have actually used it to run them on the top end. If you want hard bass out of them, it might now be enough but that’s what your subs for

polrbehr

My .02 -

I heard my RTi10s before I actually bought them (used), driven by a Cinenova Grande, of all things, so I knew my 100wpc Denon AVR would probably fall short when I got them home.

Now, it's not that they sounded bad or anything, but they definitely did lack a great deal of
the "fullness" (for lack of a better word) they exhibited during the demo when it was properly amped. Lucky for me, I found a great deal on a used Adcom GFA555 right here on Polk, so I pretty much knew it would be well worth it to grab it. Thus far, I have not been
disappointed! Using the Denon as a pre-amp for the front channels, these things now throw out sound that can be felt. Even at lower levels (like -25db or so), the RTis
just sound cleaner.

So while you can stay with an AVR for the time being, a separate amp will allow you to use
those 10s to their potential. Good luck to you, and welcome to the Club.

nm4710

Just wanted to let everyone know, I got my Onkyo M282 in today and Bi-Amp'd my RTI10's. My HK AVR245 is driving the tweets and midranges and the Onkyo amp is driving the woofers. I played around with the gain on the onkyo amp until things sounded balanced.

This combination sounds great! I've finally gotten the woofers on the RTi10s moving...the bass with music is excellent (still want my sub for HT). Additionally the higher frequencies sound slightly clearer and better staged as well. This might be because my 50watt/ch receiver is no longer trying to drive the dual 7" woofers in each RTi10. Might also be in my head.

I'm sure the sound of the RTi10s would be even sweeter with a nice adcom/rotel/carver/etc ... but this budget setup sounds great in its own right. Now it's time to break out the trusty SPL meter.

Cheers and thanks for the advice guys

bigaudiofanatic

Caption We Need MORE POWER SHE CAN'T TAKE MUCH MORE!!!!!!!!!

Kex

Good job nm4710! It makes sense that you are also noticing differences in the highs BTW: the h/k has more power to devote to its dedicated task.

I suppose this was the logic behind powered towers, which seem to have gone out of fashion now. How are you finding the center channel CSi3, which has no extra amplification?

Ron Temple

Skynut brought that amp over here this summer and it sure played nice...congrats. I'm not convinced that bi-amping with the AVR is really any benefit. Try it both ways and see which you prefer.

Willow

I really like the 3 monos set up @200wpc for my 8s and 3. They were all powered by my HK335 for a while but adding the amps was the best thing I have done in terms of sound.

xterra77

Hi
I just got rti10s and i hooked it up to my HK 230 same power as 245 and put on some music they have plenty bass.My room is 18x22 and the floor shakes.i am baffled.

Ron Temple

xterra77 wrote: »

Hi
I just got rti10s and i hooked it up to my HK 230 same power as 245 and put on some music they have plenty bass.My room is 18x22 and the floor shakes.i am baffled.

HKs have lot's of current and do a fine job at reasonable volume. You will run out of gas, if you push it. Going from 99dbs to 102dbs requires twice the power. I'm guesstimating that's where the tank would get empty. With that in mind...take it easy.

All that said, even a modest separate amp like the Audiosource Amp/One 2x80 @ 8ohms was a big improvement driving RTi 8s over an HK235. Much better detail, separation and imaging. When we recommend amplification, it's not that an AVR won't work or sound good, it just get's much better. Enjoy your Polks.

Systems

I've done a lot of analyzing of my rti12's. If you are running them on a standard "THX" EQ setting of 80 then you can run them pretty easy on 100Watts. The problem comes when you want to start driving them 3 7" woofers. I've dinked around at "full" "40" "50" "60" and 80 (THX) and even my 200Watt Outlaws just can’t punch them enough if you are running "full" in say 2 channel mode without a sub. I've considered byamping them with 2 Outlaw 2200's.. one of the top and one for the bottom but you end up being to loud on the top. The best success I had was putting my Onkyo 100watt amp on the top which has volume control on it and running the Outlaws out the back of that to the Outlaws (at full volume). That way I could power the bottoms and I could adjust the tops to match the volume of the rest of the speakers (in multi channel mode).

Of course life would be a lot better if I could find a bang for the buck amp like the Outlaw 2200's that put out 300watts. Damn.. amps start getting exponentially more expensive every watt you add after 200.

Sherardp

Silverti wrote: »

I've done a lot of analyzing of my rti12's. If you are running them on a standard "THX" EQ setting of 80 then you can run them pretty easy on 100Watts. The problem comes when you want to start driving them 3 7" woofers. I've dinked around at "full" "40" "50" "60" and 80 (THX) and even my 200Watt Outlaws just can’t punch them enough if you are running "full" in say 2 channel mode without a sub. I've considered byamping them with 2 Outlaw 2200's.. one of the top and one for the bottom but you end up being to loud on the top. The best success I had was putting my Onkyo 100watt amp on the top which has volume control on it and running the Outlaws out the back of that to the Outlaws (at full volume). That way I could power the bottoms and I could adjust the tops to match the volume of the rest of the speakers (in multi channel mode).

Of course life would be a lot better if I could find a bang for the buck amp like the Outlaw 2200's that put out 300watts. Damn.. amps start getting exponentially more expensive every watt you add after 200.

All I have to say is ICEpower my friend. Check it out. The woofers on 12s punch so hard its crazy. All you need is the ICE, best bang for buck amps other than outlaw. Check out Red Dragons, PS Audio, D-Sonic.