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RBH Sound PM-8 Monitor Measurements (from Audioholics)

hardisj

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#1
Not sure if you guys have seen this. I didn't see it mentioned anywhere. The review - by James Larson - is posted here (starting with 2nd page; the first is just intro stuff).
https://www.audioholics.com/bookshelf-speaker-reviews/rbh-pm-8-monitor/conclusion

These are ~$1600 USD EACH. $3200/pair. For the standard finish. More if you want fancier.

I replied to their YouTube channel post about it with the following:
Erin said:
Eek. $3200/pair for the 'standard' speakers? I'm not seeing that kind of performance in the supplied data. 1) Apparently a port resonance ~550Hz results in cancellation (dip). Maybe not a big deal audibly. But for $3200, that should not be there. 2) Some sort of high-Q breakup ~1200Hz. I'm guessing this is the 8-inch midwoofer (beaming is about 850Hz, so breakup above that is typical). 3) What is the crossover point for this speaker? If 48dB/octave is the slope, combined with the fact that AMT's can't generally cross as low as their dome-sized counterparts, then I'm going to guess they crossover is somewhere in the 2000-3000Hz region, based on the narrowing directivity met with wide dispersion again (per the SPIN data). IF that is the case, then what is going on @4-5kHz; cabinet diffraction? These are all educated guesses, but obviously without more information "guesses" is all they are. The (measured) performance is pretty bad. I'm sure with 8-inch woofers they have the benefit of having some output, but then again... AMTs.

Regardless of the root cause of the issues, based solely on what I am seeing, at this price the response should be immensely better. There are a lot of flaws for a $3200/pair of speakers.

My $0.02.

- Erin
Curious if you guys think I'm crazy. I'm just not seeing it.



 

MZKM

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#2
My comment on their post:

Why is the woofer on their site silver?

EDIT: Are the accent panels an attachment? If so, that changes the shape of the cabinet and will change the far off-axis horizontal response and maybe the baffle diffraction/step. So, that may address my comments below.

Honestly, not super impressed by the Spinorama, the ~3000Hz-5000Hz region is a bit wonky and dispersion between 600Hz-1500Hz is weird. It seems that they really didn’t do much DSP besides the crossover.

At $3200, I expected a bit better.
Gene replied that the woofers come in both colors (not stated on their site), and that vertical performance is great (it is) and that James loved them so they must be doing something right.

I wonder how much better the measurements would look with the panels off.
 
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hardisj

hardisj

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Thread Starter #3
My comment on their post:



Gene replied that the woofers come in both colors.

I wonder how much better the measurements would look with the panels off.
I didn't see your comment... but I do now. I agree. IMHO, RBH needs to go back to the drawing board on this one. Who cares about FIR filters if the final product isn't good? (not me)
 

richard12511

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#4
Not sure if you guys have seen this. I didn't see it mentioned anywhere. The review - by James Larson - is posted here (starting with 2nd page; the first is just intro stuff).
https://www.audioholics.com/bookshelf-speaker-reviews/rbh-pm-8-monitor/conclusion

These are ~$1600 USD EACH. $3200/pair. For the standard finish. More if you want fancier.

I replied to their YouTube channel post about it with the following:


Curious if you guys think I'm crazy. I'm just not seeing it.



I disagree that these are "pretty bad". I think we're in a bit of a bubble here at ASR, and that somewhat skews our standards. They're not great, for sure, and I see no reason to buy these when there are much better options for the price, but these are still flatter than most of what stereophile measures. I think we see a disproportionate amount of top tier speakers(Revel, KEF, Genelec, etc.) here at ASR, as those are usually the only ones people aren't afraid to send in.

*Edit: I see now this is supposed to be a studio monitor. That does somewhat change my opinion. SPDI seems to have some issues.
 
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hardisj

hardisj

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Thread Starter #5
I disagree that these are "pretty bad". I think we're in a bit of a bubble here at ASR, and that somewhat skews our standards. They're not great, for sure, and I see no reason to buy these when there are much better options for the price, but these are still flatter than most of what stereophile measures. I think we see a disproportionate amount of top tier speakers(Revel, KEF, Genelec, etc.) here at ASR, as those are usually the only ones people aren't afraid to send in.
That's fair. At least how we have been conditioned to see a lot of good stuff. But we also see a lot of bad stuff as well.

Still, for $3200/pair, I don't see any value here other than the fact they are active studio monitor speakers. An 8-inch woofer mated (seemingly poorly) to an AMT with diffraction effects and port resonance. That's what I see. And when I say that back to myself and then follow that with "for $3200/pair"... well... that's a no go.
 

richard12511

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#6
That's fair. At least how we have been conditioned to see a lot of good stuff. But we also see a lot of bad stuff as well.

Still, for $3200/pair, I don't see any value here other than the fact they are active studio monitor speakers. An 8-inch woofer mated (seemingly poorly) to an AMT with diffraction effects and port resonance. That's what I see. And when I say that back to myself and then follow that with "for $3200/pair"... well... that's a no go.
I edited my post after learning it's supposed to be a studio monitor. I think that changes things a bit. How do I view comments? I only see 1 comment that just says "Another cool review. Thanks Shady!"
 
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hardisj

hardisj

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Thread Starter #7
I disagree that these are "pretty bad". I think we're in a bit of a bubble here at ASR, and that somewhat skews our standards. They're not great, for sure, and I see no reason to buy these when there are much better options for the price, but these are still flatter than most of what stereophile measures. I think we see a disproportionate amount of top tier speakers(Revel, KEF, Genelec, etc.) here at ASR, as those are usually the only ones people aren't afraid to send in.
That's fair.

Still, for $3200/pair, I don't see any value here other than the fact they are active speakers. An 8-inch woofer mated poorly to an AMT with diffraction effects and port resonance. That's what I see. And when I say that back to myself and then follow that with "for $3200/pair"... well... that's a no go.
I edited my post after learning it's supposed to be a studio monitor. I think that changes things a bit. How do I view comments? I only see 1 comment that just says "Another cool review. Thanks Shady!"
They posted a link to the review via their YouTube channel. I can’t figure out how to link that post though.
 
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