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Klipsch RP-8000F II Floorstanding Loudspeaker Measurements & Conclusion

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8000 II outdoor testing 

The Klipsch Reference Premiere RP-8000F II speakers were measured in free-air at a height of 4 feet at a 2-meter distance from the microphone, with the microphone raised to an 8’ elevation that was level with and aimed at the tweeter center. The measurements were gated at 8 milliseconds. In this time window, some resolution is lost below 400 Hz and accuracy is completely lost below 200 Hz. Measurements have been smoothed at a 1/24 octave resolution.

8000 II 3D waterfall response 

 8000 II 2D waterfall response

The above graphs depict the RP-8000F II’s direct-axis and horizontal dispersion out to a 90-degree angle in five-degree increments. Information on how to interpret these graphs can be read in our loudspeaker measurement article. The first thing that leaps out about this response is just how linear the tweeter’s frequency band is. It is extremely flat on-axis and has a very smooth off-axis curvature. It does seem slightly elevated compared to the woofers’ bandwidth, so at the on-axis response, the RP-8000F II might sound a bit forward. We do see a slight dip at the crossover point in the far off-axis response, but it is much improved over the original RP-8000F which had a very significant off-axis crossover null that almost extended into the on-axis response. That problem has mostly been addressed here, and it’s nice to see Klipsch has acknowledged that as a problem and has fixed it. One other change we see from the original RP-8000F is that there is a lot less off-axis jaggedness in the upper treble. I speculated that the original problem was due to throat diffraction in the previous tractrix horn, but that looks like it has been cleaned up as well. There is an off-axis null at around 17kHz, but that is not going to realistically manifest itself into anything audible since it is so high in frequency. Mostly what we see is good news here. The somewhat hot tweeter could be a problem for those looking for a warmer sound but angling the speaker does help to tame the treble as we see in the below graph where we take a closer look.

8000 II individual horizontal responses3 

The above graph zooms in on some of the individual responses measured on the horizontal axis. We are taking a closer look at these to see the tweeter’s angle-specific behavior off-axis. The tweeter’s elevated response is mostly relegated from the on-axis response out to ten degrees. At the 20-degree angle, it does become more level with the woofer output. That could mean that Klipsch thought these speakers would likely have an outward, parallel-facing direction which would put the listener off-axis from about 20 to 30 degrees. On the other hand, the user manual instructs the user to position the speakers to face the listener directly in which case the user would be met with a fairly forward sound. Regardless of Klipsch’s intended voicing for the RP-8000F II speakers, this dispersion pattern enables the user to adjust the tonality to their taste. If the user likes hotter treble for a more aggressive sound, they should aim the speakers to face the listening position directly. If the user wants a neutral to warmer sound, they should angle the speakers so that the listening position is at a 20-30 degree angle of the speaker’s direct aim.     

8000 II Polar Map 

The above polar map shows the same information in the preceding graphs but depicts it in a way that can offer new insight regarding these speakers’ behavior. Instead of using individual raised lines to illustrate amplitude, polar maps use color to portray amplitude, and this allows the use of a purely angle/frequency axis perspective. The advantage of these graphs is they can let us see broader trends of the speaker’s dispersion behavior more easily. More information about interpreting this graph can be read in this article.

The original RP-8000F had a nicely controlled directivity, and this improves on it by lessening the off-axis null at the crossover frequency. Klipsch’s hybrid tractrix waveguide does a very good job of controlling the dispersion all the way up to 16kHz. As with the original RP-8000F, that makes these speakers a good candidate for a time-intensity trading placement as I found out in my own listening. It also means that these speakers can be equalized with predictable results since any acoustic reflection will generally follow the spectral changes made to the first arrival of sound at the listening position. This kind of dispersion pattern plays well with auto-EQ systems like Dirac or Audyssey. The controlled directivity exhibited here also lessens the need for acoustic treatments since this narrower dispersion leads to fewer acoustic reflections. This graph also tells us that any listeners will need to be seated within a 40-degree angle or else the treble will be greatly diminished.

8000 II vertical responses 

The above graph is a sampling of some of the vertical angle responses at and around the on-axis angle. Negative degrees indicate angles below the tweeter, positive angles indicate angles above the tweeter, and zero degrees is level with the tweeter. These measurements tell us that the RP-8000F II is best listened at within a 5-degree angle and listening at a height level with the tweeter is clearly the best choice. Moving up by just 10 degrees from the tweeter height creates a large gap in the crossover region. The RP-8000F II seems to be a bit more sensitive to height differences than a typical speaker. The good news is that at a 37” height, the tweeter is set at an altitude that most users will have their ears near in a normal seating position.

 8000 II low frequency resppnse

The above graph shows the RP-8000F II’s low-frequency response captured using groundplane measurements (where the speaker and microphone are on the ground at a 2-meter distance in a wide-open area). The RP-8000F II’s port tuning frequency is at 40Hz much like the original RP-8000F. It holds a flat bass response from 40Hz all the way to almost 300Hz above which it does rise a bit. The original RP-8000F had a bass-heavy sound in my room while this version does not despite having a very similar low-frequency response, and I believe that the reason is the range above what is shown here, especially in the tweeter band, is high in level, and so while I was getting the same room gain as the original RP-8000F, it only gave the bass response parity with the midrange and treble. 40Hz isn’t a very low tuning frequency for a tower speaker, but it is one of the ways that Klipsch achieves a higher sensitivity and wide dynamic range. With room gain, most people should get a bass response to around 30Hz or slightly above that point, and that should be enough to catch the bass of virtually all acoustic music except for some pipe organ recordings, and most other types of music too. It is enough to get much of the bass in movies, although it will miss the deeper bass. The RP-8000F II doesn’t bother with the lowest octave, but it is still a full-sounding speaker. Users who want serious output below 40hz will need to add a subwoofer, but that is probably what most people are going to be doing anyway.

 8000 II Impedance

The above graph shows the electrical behavior of the Klipsch Reference Premiere RP-8000F II. Klipsch specifies it to be 8 ohms, but that is not what our measurement shows. The entirety of the mid and upper bass stays well below 8 ohms, and this is a very heavily used range. I think Klipsch spec’d it at 8 ohms because some AVRs are listed to only drive 8-ohm speakers, and owners who abide by those guidelines might avoid these speakers on account of their actual impedance. The truth is many AVRs list that guideline as a spec for overcautious liability reasons, and all but the jankiest amplifiers can handle lower impedance loads, although perhaps not at a very high amplitude for an extended period of time. The impedance and phase seen here are nothing to worry about for any midrange AVR or amplifier. There are some wrinkles in the response from 200Hz to 400Hz, and my guess is that those are due to port resonances since the enclosure itself is well-braced. The port system that Klipsch has implemented is an odd one with both woofers being given their own compartments with their own tractrix port. Something else we can see is that the dip in the low-frequency saddle bottoms out at 40Hz which corresponds to the knee of the acoustic bass response thereby confirming 40Hz as the port tuning frequency.

I measured the sensitivity of the RP-8000F II to be 92.2dB for 2.83v at 1 meter. This actually matches Klipsch’s own spec of 98dB half-space for 2.83dB at 1 meter. In order to get a half-space sensitivity, simply add 6dB onto an anechoic sensitivity measurement. When we do that, my measurement is only 0.2dB away from Klipsch’s. While I would prefer that Klipsch simply list their sensitivity anechoically, at least they are now giving context to their spec which is not what they had been doing previously, so that is an improvement. 92dB is above average sensitivity, even for tower speakers. A monster amp is not needed to drive these to very loud levels. Indeed, with a maximum 150-watt RMS power-handling specification, they wouldn’t be able to handle a monster amp anyway. A normal AVR could make these get louder than most people would tolerate.

Conclusion

8000 II pair hero2Before bringing this review to a close, I will briefly go over the strengths and weaknesses of the product under review, and, as usual, I will start with the weaknesses. The chief weakness of the RP-8000F II is also a strength; in order to get the best sound from it, you have to position it correctly. However, the ‘best sound’ will vary from person to person, so this variability to change the sound character also has benefits. But a problem with that is not many buyers will realize this quality of the speaker, and Klipsch’s user manual is no help. In fact, the user manual probably leads to a placement that will cause an unfavorable sound for many people. The source of the problem is that the tweeter’s on-axis level is elevated compared to that of the woofers. Going from 1.6kHz to 200Hz, there is somewhere between a 3dB to 4dB drop in amplitude. That means that these speakers could sound somewhat thin for those who actually use Klipsch’s own placement suggestions, especially if they are using these speakers in a room and placement that doesn’t get much low-end acoustic room gain. Of course, for those who don’t want a treble-heavy sound, the solution is, as we have discussed, to angle the speaker where the tweeter’s output is reduced to a more even level with the woofers, and this occurs around a 20-30 degree angle. The good news about that is a lot of people will probably default to that kind of listening position angle anyway by placing the speakers to face straight ahead from a wall.

Another reason that the decision to have a lowered bass level relative to the tweeters was a strange one is that the RP-8000F IIs are somewhat large speakers, so buyers may pick them over the smaller models for a larger room. The problem with that is that the lowered bass level would depend on room gain to attain an even level with the tweeter output, at least at or around the on-axis angle, but larger rooms don’t tend to generate as much low-end gain as medium-sized to smaller rooms. Again, the solution is simply to angle the speakers so that the tweeter is aimed away from the listening position at a 20-degree angle or further, but this all would have been simpler if Klipsch had simply opted for a flat response from top to bottom. My guess is that Klipsch’s reasoning for this is that they found most owners place the speakers close to the back wall where they would get a significant amount of boundary gain in bass frequencies, so this is not an unreasonable strategy. However many audio enthusiasts will give their speakers a significant stand-off distance from walls as well as toe them in so that the speakers face the listener, and such a placement is bound to produce a thin, lackluster sound. Most tower speaker manufacturers attenuate the low end of their speakers to some degree to compensate for room gain, but many over-damped low-frequency responses that we have seen in the past do allow for more placement flexibility without risking too much or too little boost in the bass range.

So my only real complaint about the RP-8000F IIs is how the amplitude response makes the speaker a bit fussy about placement and positioning to get a very good sound. Now let’s move on to the positive attributes of the RP-8000F IIs, and one of those is that you can get a very good sound although it might take a little bit more effort and experimentation. Despite my gripes about the lowered bass response, I did feel that the bass sounded more natural than that of the original RP-8000F which did almost nothing to compensate for low-end room gain. My room does get a fair amount of low-end room gain, so the lowered bass response of the RP-8000F IIs ended up giving me a more balanced sound. If you want more bass from these or any other speakers, all you need to do is place them closer to a wall or nearby surface. The good news about their specific design in this respect is that they will play nicer with the acoustics of being placed nearer to walls and nearby surfaces since their narrow dispersion will lead to less acoustic reflections from sidewalls. In other words, there are fewer acoustic penalties for placing these speakers in corners or next to sidewalls if that placement is required.

8000 II pairOnce set up right, you can get a nicely balanced sound with bass that is powerful but not overbearing and treble that is crisp but not harsh. The RP-8000F IIs have dynamic range to spare and do NOT require a monster amplifier to drive to loud levels. Most people will be more than satisfied with what a typical AVR could do with them. The low-frequency extension is OK for a tower speaker, but those who are after the deepest bass in modern movie sound mixes will want to add a subwoofer, preferably with extension to 20Hz to fully obtain that last octave. The imaging from the RP-8000F IIs can be superb, and, as discussed before, they are good candidates for a time-intensity trading placement which can have a wider sweet spot for imaging than typical loudspeakers. If you can not accommodate a center speaker, this is a way to get good imaging outside of the small sweet spot that most speakers project.

Outside of the sound, the aesthetics and build quality are good. They don’t look bad, and I think the copper accents are a nice touch and keep them interesting and distinctive. The cabinet is a bit large but has a very good series of internal braces, so it has a sense of sturdiness. I can also appreciate how Klipsch has arranged the feet; they give speakers a good footing without becoming a big plinth or some large outriggers with spiked feet.

In the introduction to this review, we asked if the RP-8000F II was a substantial improvement over the original RP-8000F, and do those improvements justify the price increase. I would say that the RP-8000F II is largely an improvement. The original did have a flatter on-axis response across its entire frequency band, but other than that, this sequel speaker is superior on every front: better build, better crossover, better waveguide. Does all that justify the price increase over the original? When we factor in inflation, I would say YES. It is a significant improvement but not a huge improvement. However, the original would have had to incur a price hike to keep up with inflation anyway, much as so many other commodities. The original RP-8000F was a good speaker, but this one is better.    

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

  • StarStarStarStarStar — Excellent
  • StarStarStarStar — Very Good
  • StarStarStar — Good
  • StarStar — Fair
  • Star — Poor
MetricRating
Build QualityStarStarStarStar
AppearanceStarStarStarStar
Treble ExtensionStarStarStarStar
Treble SmoothnessStarStarStarStarStar
Midrange AccuracyStarStarStar
Bass ExtensionStarStarStar
Bass AccuracyStarStarStarStar
ImagingStarStarStarStarStar
Dynamic RangeStarStarStarStarStar
Fit and FinishStarStarStarStar
PerformanceStarStarStarStar
ValueStarStarStarStar
About the author:

James Larson is Audioholics' primary loudspeaker and subwoofer reviewer on account of his deep knowledge of loudspeaker functioning and performance and also his overall enthusiasm toward moving the state of audio science forward.

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shadyJ posts on November 27, 2022 03:07
Hugystyle, post: 1581001, member: 99786
The fact to limit equalization above a given frequency. The audissey app give you this option. This great video explaining this between other things
gmsxGPub-oA

On a side note for shady, i am also still iterating on imaging vs treble. Right now i toed in the speakers and decreased treble tonality. Is it a viable approach ? Or it s better to keep native treble and not toe in at all ? I have 3 meters between each speaker and 3 meters between speakers and listening spot.
Thx for your help !
To answer your question, the short version is that if you want the strongest treble, angle the speakers to face you directly. The further away from you that the speakers are facing will taper off treble energy- that isn;t a bad thing, but rather just a matter of personal preference. It can also affect imaging. The more inward that you face the speakers, the sharper the imaging can become, but that might come at the cost of spaciousness and envelopment.

The long answer to your question is contained in these videos that Audioholics did with Matthew Poes. Those videos are worth watching, especially since you have more controlled directivity speakers.
lovinthehd posts on November 26, 2022 20:52
Hugystyle, post: 1581001, member: 99786
The fact to limit equalization above a given frequency. The audissey app give you this option. This great video explaining this between other things
gmsxGPub-oA

On a side note for shady, i am also still iterating on imaging vs treble. Right now i toed in the speakers and decreased treble tonality. Is it a viable approach ? Or it s better to keep native treble and not toe in at all ? I have 3 meters between each speaker and 3 meters between speakers and listening spot.
Thx for your help !
Thought that's what it was but some might refer to LPF of LFE…..
Hugystyle posts on November 26, 2022 20:34
lovinthehd, post: 1580996, member: 61636
Cutoff?
The fact to limit equalization above a given frequency. The audissey app give you this option. This great video explaining this between other things
gmsxGPub-oA

On a side note for shady, i am also still iterating on imaging vs treble. Right now i toed in the speakers and decreased treble tonality. Is it a viable approach ? Or it s better to keep native treble and not toe in at all ? I have 3 meters between each speaker and 3 meters between speakers and listening spot.
Thx for your help !
lovinthehd posts on November 26, 2022 19:46
Hugystyle, post: 1580881, member: 99786
Hey there! Just bought those beauties on sales. Managed quite quickly to find a correct positioning compromise thanks to your advises. I am using it in a home cinema set up with a marantz 5015 and I was wondering how should i set the crossover and cutoff ? Right now it s at small 80hz and cutoff at 200hz. My room has strictly no sound treatment. Thanks for your help
Cutoff?
shadyJ posts on November 25, 2022 22:53
Hugystyle, post: 1580881, member: 99786
Hey there! Just bought those beauties on sales. Managed quite quickly to find a correct positioning compromise thanks to your advises. I am using it in a home cinema set up with a marantz 5015 and I was wondering how should i set the crossover and cutoff ? Right now it s at small 80hz and cutoff at 200hz. My room has strictly no sound treatment. Thanks for your help
Your settings sound about right. You can play with the crossover if you want to see if you like the sound of more or less of the bandwidth going to the speakers. I would experiment with 60Hz to 100Hz. Just go with whatever sounds best to your ears. Most people stay with 80Hz which is perfectly fine too.
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