RF-7II 's And Krell S-300i Integrated

[Codyred]

Due to the fact that I haven't gotten the bass I expect from my RF7 II's and had to use a subwoofer in my family room, I have been on the hunt for an integrated amplifier with more grunt.  I've been looking for a high current integrated (not just high power): one that doubles it's power as the impedance lowers.  Came across the Krell S-300i which is a high current integrated. Trying out an Anthem 225 integrated right now, which is very powerful, but this pairing without the addition of a sub doesn't quite have me convinced to stop looking at a better matching integrated amp yet.   

 

From my reading here, with the RF7II's at 120hz the speaker's impedance drops to 2.8 - 3 ohms, which explains why although they are efficient speakers they still require current to get the woofers moving.  The Krell S-300i by many accounts is smoother than traditional old school Krell, but still has the Krell sound and bass.  This amp will also have a Synergistic Research Quantum fuse installed which is also known for smoothing the sound signature.  I know some frown on pairing Krell with Klipsch.  Have you heard this pairing?  Do you think it has potential?

 

Thanks for sharing.

 

 

[Zen Traveler]

Welcome to the Forum, Fwiw, the RF-7s were designed to be paired with a subwoofer. Insofar as you question about the impedance of the RF-7IIs,  there is a Frequency Response Chart going around here taken from an AVS Forum member and I think the RF-7IIs only dropped as low as 3.8 Ohms in a couple of points higher than you would direct to the sub--If I remember the posters name I will provide a link.

[Zen Traveler]

Here is the thread I was thinking of: https://www.avsforum.com/forum/89-speakers/1412510-klipsch-rf7-ii-measurements.html

[Codyred]

Thanks Zen, but some here and at other forums have posted about strong bass from the RF7II's without a subwoofer.  From their reports, I believe the potential of the speakers exists.  

 

Chuck Hawks: "I am very pleased with the RF-7 II's. Good detail and a nice stereo sound stage, extended bass,"

 

One fellow here said: The high end is crystal clear with zero harshness the midrange is very clean large and real sounding (not artificial sounding like so many speakers are) the bass even with no sub will kick your chest! 

[Zen Traveler]

Good luck in your quest, but I imagine some of that is hyperbole...I absolutely love our HT listed below and the RF-7s are awesome speakers--That said, any "kicking in the chest," pales in comparison when you have a capable sub in the mix and that includes music, imo. I also realize this is a 2 channel discussion and some don't wish to include a sub in that material. 

[Codyred]

Thanks Zen! I have a good sub (Earthquake supernova), just don't want to have to use it to hear (feel) satisfying low end. The quotes I posted are not the only ones who have commented on the good bass extension of the RF7II's on their own. 

[Zen Traveler]

Cool. Fwiw, my guess is you aren't even getting close to the limits of your Anthem and changing amps isn't going to improve the bass response (unless you are in a really large room)...Another thing to look at is the room they are set up in. That's my 2 cents and hope you have more satisfying responses. Usually folks love giving 2nd opinions.  

[mimalmo]

I owned a Krell 300i back in the day and while it can deliver the right amount of power for strong bass, there's no substitute for a properly placed subwoofer that's been dialed-in when it comes to the very bottom octave.

[Ceptorman]

2 hours ago, mimalmo said:

I owned a Krell 300i back in the day and while it can deliver the right amount of power for strong bass, there's no substitute for a properly placed subwoofer that's been dialed-in when it comes to the very bottom octave.

This is true. Very few full range speakers can get low enough to provide a full spectrum of lower bass frequencies. A sub is essential. 

[billybob]

Just for kicks try them without a sub for a bit then...decide.

[robert_kc]

OP:  What genres of music do you listen to?   Is the same system used for movies?

 

I listen to classical music and opera.   I use RF-7II (left, center, and right) with tube amps.   IME, RF-7II deliver fairly powerful bass when driven with a 30wpc tube amp.   However, I use subwoofers (SVS SB16-Ultra and Klipsch R-115SW), crossed-over via an Oppo UDP-205, in order to deliver the full dynamic range, and frequency range, of a large-scale symphony orchestra.

 

I believe that each person must define their goals for their hi-fi system (or home theater system).  

 

Is your goal to reproduce the natural timbre – and the full dynamic range and frequency range - of orchestral instruments at realistic sound levels (i.e., concert hall levels) in an average size room?   For a string quartet?  For Mahler’s Symphony No. 2?   Do you want to reproduce the lowest pedal notes of a pipe organ?  Different genres of music place significantly different demands on a hi-fi system. 

 

For movies, do you want to feel the impact of explosions, and the rumble of a buffalo stampede?

 

In an average size room, at reasonable sound levels, IME for most music RF-7II perform OK without a sub.   However, large powered subs help deliver the full impact of hi-res recordings (e.g., SACD, Blu-ray) of music that contains significant dynamic range, and significant low frequencies.  I don’t think a different amp “with more grunt” is the answer.  I’d stick with a main amp that delivers “musical sound quality” (IMO a tube amp), and if you want full dynamics and full frequency range, then off-load the main amp and speakers with a crossover before the amp (e.g., Oppo universal player), and use large powered subs.  IME, this works great for hi-res recordings of large-scale music, and for movies with LFE (low-frequency effects).

 

[Zen Traveler]

1 hour ago, billybob said:

Just for kicks try them without a sub for a bit then...decide.

Yup. It's why I use a (2) sub but different strokes for different folks, as they say. 

[Zen Traveler]

8 minutes ago, robert_kc said:

However, I use subwoofers (SVS SB16-Ultra and Klipsch R-115SW), crossed-over via an Oppo UDP-205, in order to deliver the full dynamic range, and frequency range, of a large-scale symphony orchestra.

I look at the RF-7s being a 2-way speaker and when you cross the lower end over to the sub(s) it becomes a 3-way speaker system. 

[billybob]

Yes Zen, may be a generational thing but, as always trying to go with  2 channel. Even my Chorus with those 2 honkin...K-48-E always did it for me...at volume and less...awesome.

5 minutes ago, Zen Traveler said:

Yup. It's why I use a (2) sub but different strokes for different folks, as they say. 

 

[pallpoul]

I use my RF-7 III's without a sub. I find the bass more then enough, but that's my preference. Your taste may require more, so add a sub or 2 and compare. let us know pls. 

[billybob]

If, and think that they do the Chorus requires watts then, by a similar token, the RF-7II would as well. if, your object is for the most part, 2 channel. If you are stuck on an integrated, keep that in mind. Any headroom above your listening level, will be appreciated.

[Codyred]

I listen to mostly classic jazz from the 50's and I do have an Earthquake Supernova IV subwoofer that I've been using. Since I'm trying an Anthem 225 integrated now, I have yet to hook up the sub because I hoped for more performance in the low end with this powerful integrated. It appears that the integrated is not the perfect match for the RF7II's, although pretty good sonically so far. Been thinking that a true (actual) high current integrated might bring more bass weight, since high current means the ability of an amp to double its power as the speaker impedance dips from 8 ohms to 4 ohms (sometimes even to 2 ohms in very expensive amps).. The Krell S-300i is high current not just high wattage, which made me interested. I have heard some say they get plenty of bass from the RF7II's and some say you they need a sub, but I do have a tough room that may be a big part of my problem--(concrete slab with the wall behind the speakers being brick with FR7II's on the short wall -and no ability to rearrange the family room for a better setup.

[Shiva]

29 minutes ago, Codyred said:

I listen to mostly classic jazz from the 50's and I do have an Earthquake Supernova IV subwoofer that I've been using. Since I'm trying an Anthem 225 integrated now, I have yet to hook up the sub because I hoped for more performance in the low end with this powerful integrated. It appears that the integrated is not the perfect match for the RF7II's, although pretty good sonically so far. Been thinking that a true (actual) high current integrated might bring more bass weight, since high current means the ability of an amp to double its power as the speaker impedance dips from 8 ohms to 4 ohms (sometimes even to 2 ohms in very expensive amps).. The Krell S-300i is high current not just high wattage, which made me interested. I have heard some say they get plenty of bass from the RF7II's and some say you they need a sub, but I do have a tough room that may be a big part of my problem--(concrete slab with the wall behind the speakers being brick with FR7II's on the short wall -and no ability to rearrange the family room for a better setup.

Nothing wrong with trying to get the most out of ones speakers. The Anthem you have has very nice reviews and is supposed to be good for bass too.  Perhaps, it is a room issue.    How far from the front wall are they?  Maybe your sitting position is in a null.  Have you noticed in some parts of the room, the bass is fuller than other areas?   Have you tried playing bass heavy music such as techno dance or rap through them to test the RF7's limit?   

[Zen Traveler]

44 minutes ago, Codyred said:

It appears that the integrated is not the perfect match for the RF7II's, although pretty good sonically so far. Been thinking that a true (actual) high current integrated might bring more bass weight, since high current means the ability of an amp to double its power as the speaker impedance dips from 8 ohms to 4 ohms (sometimes even to 2 ohms in very expensive amps)..

I look at it from the pov of what it takes to drive my speakers (with the headroom and volume in mind) and work backwards....That said, I can't imagine you don't have enough current to drive RF-7IIs to their potential and switching out SS amps is not going to matter as much as what is doing the processing. 

 

44 minutes ago, Codyred said:

I have heard some say they get plenty of bass from the RF7II's and some say you they need a sub, 

They do have good bass when played alone but definitely not something you "feel in your chest" regardless of what you are powering them with when compared to using a sub on the same material.

Quote

 

but I do have a tough room that may be a big part of my problem--(concrete slab with the wall behind the speakers being brick with FR7II's on the short wall -and no ability to rearrange the family room for a better setup.

This may be the culprit but once you hook up your sub it may alleviate any problem you are experiencing with bass---It did for me. Good luck.

[Codyred]

20 minutes ago, Zen Traveler said:

I look at it from the pov of what it takes to drive my speakers (with the headroom and volume in mind) and work backwards....That said, I can't imagine you don't have enough current to drive RF-7IIs to their potential and switching out SS amps is not going to matter as much as what is doing the processing. 

 

They do have good bass when played alone but definitely not something you "feel in your chest" regardless of what you are powering them with when compared to using a sub on the same material.

This may be the culprit but once you hook up your sub it may alleviate any problem you are experiencing with bass---It did for me. Good luck.

Thanks for hanging in there with me Zen! I will likely do just that today!. Just disconnected it when I got the 225.