Klipsch RP-600M Speaker Review

[Verdinut]

I disagree that the dip at the crossover point was intentional. The drivers are out of phase and, in my opinion, an attempt should have been done to reverse connection of one driver to see if the situation would improve the response curve to acceptability.

 

[John Atkinson]

I disagree that the dip at the crossover point was intentional. The drivers are out of phase . . .

The RP600M's tweeter and woofer are connected in the same polarity - see fig.7 at https://www.stereophile.com/content/klipsch-reference-premiere-rp-600m-loudspeaker-measurements - and while fig.4 at that URL shows the acoustic crossover slopes, 4th-order high-pass on the tweeter, close to 3rd-order low-pass on the woofer, it doesn't show the phase of the drive-units in the crossover region.

John Atkinson
Technical Editor, Stereophile

 

[Verdinut]

The RP600M's tweeter and woofer are connected in the same polarity - see fig.7 at https://www.stereophile.com/content/klipsch-reference-premiere-rp-600m-loudspeaker-measurements - and while fig.4 at that URL shows the acoustic crossover slopes, 4th-order high-pass on the tweeter, close to 3rd-order low-pass on e woofer, it doesn't show the phase of the drive-units in the crossover region.

John Atkinson
Technical Editor, Stereophile

The speaker which was tested was a refurbished one. Isn't it possible that the connection to one of the drivers was reversed inadvertently?

 

[HammerSandwich]

Stereophile's measurements are similar to ASR's. Would they match if 1 speaker were assembled incorrectly?

 

[ctrl]

No i do not. But trust me, the difference was too much. I expected a little improvement but not so much, hence the thread I opened because I was surprised. Perhaps it is the sum of two factors: a poor quality (value and more inductance) of the originals and a much better quality of the new ones, which would explain so much difference.

Unfortunately no, it is pure imagination if the impedance values are really identical.
See my review "Replace resistor by low-inductance resistor - Is it audible?".

 

[Verdinut]

Stereophile's measurements are similar to ASR's. Would they match if 1 speaker were assembled incorrectly?

No, they wouldn't match. It looks that Klipsch connected them intentionally as they are, but that doesn't prove that they are operating in acoustical phase. They can be connected in the same polarity and that doesn't mean that they are physically in phase because of their relative positions.

In my opinion, it was worth a try to reverse the connection on one of the drivers. But nobody thought about it to see if an appreciable improvement in the response as I think might have resulted.

 

[amirm]

Stereophile's measurements are similar to ASR's. Would they match if 1 speaker were assembled incorrectly?

As are the GR research measurements shown in the video earlier.

 

[amirm]

In my opinion, it was worth a try to reverse the connection on one of the drivers. But nobody thought about it to see if an appreciable improvement in the response as I think might have resulted.

Your opinion needs to have enough weight for me to stop testing the next speaker, disassemble this one, change its wiring, test, publish the results, then reverse the change. With no less than three independent measurements showing exactly the same issue, you just have not made a case for this.

 

[Deleted member 2944]

No, they wouldn't match. It looks that Klipsch connected them intentionally as they are, but that doesn't prove that they are operating in acoustical phase. They can be connected in the same polarity and that doesn't mean that they are physically in phase because of their relative positions.

In my opinion, it was worth a try to reverse the connection on one of the drivers. But nobody thought about it to see if an appreciable improvement in the response as I think might have resulted.

There's no rule that says adjacent drivers need to be in phase at the crossover frequency. In fact, many speakers are designed that way.
Indeed, the polarity-reversing testing technique only works for speakers with even-order crossovers.

And, assuming this speaker does have a designed even-order crossover, with the tweeter incorrectly wired, the measured null should be MUCH deeper than it is.

Dave.

 

[Jon L]

Your opinion needs to have enough weight for me to stop testing the next speaker, disassemble this one, change its wiring, test, publish the results, then reverse the change. With no less than three independent measurements showing exactly the same issue, you just have not made a case for this.

Klipsch RP600M has biwire speaker binding posts, so it should be easy enough to reverse the connection to one of the drivers at the binding posts with some wire.
Maybe I'll try that myself since I already replaced the stock brass plates with OCC copper wire already.

 

[Ron Texas]

This speaker was an excellent choice for review. It's in production, easily available and widely reviewed. Members are looking to purchase these and need the best information available. Measurements made with the Klippel system are far better than putting the speaker on a stand outdoors. The LS50, R3 and Revel reviews also had these attributes. Recent Elac speakers up to the $2k price point would also fall into this category.

 

[Verdinut]

There's no rule that says adjacent drivers need to be in phase at the crossover frequency. In fact, many speakers are designed that way.
Indeed, the polarity-reversing testing technique only works for speakers with even-order crossovers.

And, assuming this speaker does have a designed even-order crossover with a tweeter incorrectly wired, the measured null should be MUCH deeper than it is.

Dave.

What you say is not always exact. The polarity might have to be changed because of the different vertical physical alignment of drivers in the enclosure.

Your opinion needs to have enough weight for me to stop testing the next speaker, disassemble this one, change its wiring, test, publish the results, then reverse the change. With no less than three independent measurements showing exactly the same issue, you just have not made a case for this.

So it looks like nobody will know exactly what reversing polarity on one of the drivers would have done to the frequency response curve. It would have indeed been good to have someone do it.

 

[stevenswall]

I like that in most videos this guy ranks things which forces him away from the "everything is awesome" or "every sound signature and flaw has a person who will like it" nonsense.

As subjective as many reviewers have to be, I appreciate when they try like this. Curious what most people think the future "should be" for reviewers who try to be fair but don't have the resources of ASR.

Maybe just talking about features and the preference scores here and showing their appearance on video?

Or is this just worrying to much about saving the candlemakers (subjective YouTube channels) from the threat of the lightbulb (Audio Science Review.)

Also: I really respect this guy's channel. He often does some limited measurements with the equipment he has an talks about positioning and how that measurably affects things.

 

[Xulonn]

Also: I really respect this guy's channel. He often does some limited measurements with the equipment he has an talks about positioning and how that measurably affects things.

Without specifically stating what it means, he basically said that these speakers only sound good when you toe them in and align your ears perfectly in line with a spot between the tweeter and woofer. I don't want speakers that require such a narrowly defined listening position.

However, that conclusion seems to conflict with Amir's review that said "The 'horn' is actually not a horn but a waveguide that is doing its job to provide uniform off-axis response allowing one to EQ the mid-range dip."

Am I confused, or do Amir and Joe seem to have reached opposite conclusions about this speaker?

 

[amirm]

Am I confused, or do Amir and Joe seem to have reached opposite conclusions about this speaker?

You are not confused.

 

[BYRTT]

Stereophile's measurements are similar to ASR's. Would they match if 1 speaker were assembled incorrectly?

...So it looks like nobody will know exactly what reversing polarity on one of the drivers would have done to the frequency response curve. It would have indeed been good to have someone do it.

Model is not 100% waterproof because used slopes is the measured ones from stereophile (thanks) upon ASR spin data files and one has to kind of interpolate them into best as possible position, but think model should be good enough for flipped polarity exercise, effect looks to kind of amplyfi HRTF interference in a stereo triangle

 

[Verdinut]

Model is not 100% waterproof because used slopes is the measured ones from stereophile (thanks) upon ASR spin data files and one has to kind of interpolate them into best as possible position, but think model should be good enough for flipped polarity exercise, effect looks to kind of amplyfi HRTF interference in a stereo triangle
View attachment 55342

If those graphs are accurate, they just clearly indicate that the crossover is badly designed. It's nothing new. It's a fact that many speaker manufacturers don't have the qualified personnel to design smooth passive crossovers. The curves clearly show that the woofer response start to slope down at a too low frequency, whereas the tweeter's knee frequency is too high, so their responses fail to properly cross at a specified frequency.

 

[ROOSKIE]

If those graphs are accurate, they just clearly indicate that the crossover is badly designed. It's nothing new. It's a fact that many speaker manufacturers don't have the qualified personnel to design smooth passive crossovers. The curves clearly show that the woofer response start to slope down at a too low frequency, whereas the tweeter's knee frequency is too high, so their responses fail to properly cross at a specified frequency.

Honestly it has been said here already - even by me. I really, really think this is by design. I was into DIY. Free software exists, cheap measuring tools and enough help from just the motley crew at parts express to make a better design in terms of flat response. I guarantee you I could in one day. There is no way Klipsch doesn't have access to more powerful tools. They want this response - all of it. It is selling very, very, very well.
And best of all it sounds different in listening rooms. Lots of systems sound the same - these stand out for good bad they stand out and some people will be into that fact alone.
Klipsch "ain't" into flat response curves. Not their goal.

 

[Verdinut]

Honestly it has been said here already - even by me. I really, really think this is by design. I was into DIY. Free software exists, cheap measuring tools and enough help from just the motley crew at parts express to make a better design in terms of flat response. I guarantee you I could in one day. There is no way Klipsch doesn't have access to more powerful tools. They want this response - all of it. It is selling very, very, very well.
And best of all it sounds different in listening rooms. Lots of systems sound the same - these stand out for good bad they stand out and some people will be into that fact alone.
Klipsch "ain't" into flat response curves. Not their goal.

Same with Bowers & Wilkins and some others.

 

[ROOSKIE]

Same with Bower & Wilkins and some others.

Yah one of the forum members reviewed the active BW DUO and the measurements kinda were crap. All the DSP available and they still don't go for flat. They have a whole other thing going. Not sure what their intent is but is something...