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Purifi 1et400a monoblocks with Revel M126be?

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I will tell you what I see and think with the caveat that I have a moderate understanding of the RT60 and decay curves and there are others that are far more sophisticated than I am. Working backwards:

  • In looking at the waterfall, I am looking to see if there is any real unevenness in the decay times that could leads to the excess of energy we from about 500 hz up to about 2k hz when we look at your frequency response graphs. The if there is, it is your room causing the excess energy, not the speaker. What I see in your waterfall is a very even and consistent decay across that frequency range. The RT 60 range confirms that, showing decay times from 250-350 ms, which is a well dampened (actually slightly over dampened) room. This means the excess energy in that range is your speakers, not the room. It also means you should not add any dampening to the room, it will make it too dead.
  • The Rt60 also shows you have a bit of ringing in the 120hz area (which isn't there on the waterfall) and the waterfall shows your room mode at 40hz with a long decay. It appears from it your room is relatively square. There is no reasonable room treatment that will fix this issue, we all have large modes in the bass, don't worry about it too much, this is where your room correction software is useful.
  • Remember, unless there is something really off with the room, the speaker's voicing dominates the sound above the Schroeder frequency, the room below it. The Schroeder frequency in most rooms is about 200hz (it can be calculated with the room dimensions.
So now that we know how your room is measuring, lets look at your speakers and what we can do with them:
  • We are fortunate, Stereophile has measured your Spendors so we have some good data on them: https://www.stereophile.com/content/spendor-a7-loudspeaker-measurements . I see a few things that stand out that I don't like in measuring them and would lead to them being less than optimal in your room:
    • Depending on how your look at it, they either have a broad suckout from 100-600 hz or a broad plateau from 700-10,000 hz.
    • Their bass is strange. Generally we will see a from a very slight to a broader bump centered at about 100hz in the stereophile measurements, see these examples:
    • Your speakers don't have this bump. Rather they have a huge suckout from 150-200 hz and then a peak at 55hz. As a result their -10db point is about 30hz and at 40 hz they are only down a couple of db, which means they are going to really aggravate your room mode. They probably still aggravate it with an 80hz hp because of this weird response. Since you are using a Mini DSP, try 36db octave on them.
    • Generally, when looking at an in room response, we like to see a 5-6 db overall drop from about 100hz to 10k. We have the opposite in your room, which is going to lead to a forward and thin sound, with a big fat boom at 40hz because of their strange bass response.
    • Before you buy other speakers, give the following a try with your mini dsp:
      • Change your high pass to 36db/oct at 80 hz.
      • Add a -3db 1.0q filter at 1,200 hz.
      • Add three high shelf filters, one at 215hz, one at 1000 hz, and one at 4642 hz, all -1.7db with a q of .5
    • The foregoing filters should help with the broad midrange peak and add a bit of a house curve. Let us know how this sounds. It should help some, but your Spendors have inconsistent off axis response which will limit the effectiveness of using an EQ.
So looking at alternative speakers, her are my thoughts:
  • Most floor standing speakers should work well in your room, especially when used with a crossover. The issue you having with your current speakers aggravating your bass mode appears to be due to their peaking close to your mode frequency. Even with a 24db octave filter at 80hz they still are putting out significant bass. Compare that to even a Revel F228be or Kef Reference 5, both of which have good strong bass, but not a peak at 50 hz and you will see that they have about 5-6 db less energy at 40 hz relative to the midrange (4 times less energy).
  • I am a believer that even crossed over, your main speakers should, if possible, offer a relatively linear response to 1 octave below the crossover frequency. This means down to 40hz. This gives a more predicable transition from the mains to the subs. It also favors floor standing speakers over bookshelves.
  • I would not get concerned about the BMR's extending down to 32hz. Their bass is highly dampened with a -3 db of 62hz and -10db of 35hz. Combined with your crossover, even counting room gain, and they should be at least 20db down at your room mode of 40hz. See Erin's measurements here: https://www.erinsaudiocorner.com/loudspeakers/philharmonic_bmr/
  • If you look outside the Revel camp, you may be able to find better values in the UK. I would suggest checking out some KEFs, Elac and Dynaudio speakers also, all of which are engineering focused companies. Harbeth may also be a good choice as they are UK based. Also, the Wharfedale Linton Heritage come in walnut and could be a good fit.
  • I would also suggest you consider the Salk Song 3 speakers. https://www.salksound.com/model.php?model=song3 Not sure what they would cost shipped to your door. I had a pair and they were very good sounding, transparent, and the tweeter sounded a bit sweeter and better than my Revels. The reason I didn't keep them was they had a very flat and dampened bass, where I like a bit of hump like the F208s have. For you, they could be a really good fit, plus you can get them made to exactly match your existing furniture.
I know it is a lot to digest, with perhaps not the best explanations, but I hope this helps sum up what I see as the problems you are experiencing with your current speakers, how to try and correct them in the meantime, and what to look for in a replacement pair.

Wow..... I hope you don't mind but I need so time to digest all this info! :)

I will say that you've hit the nail on the head with regards to how my Spendors interact with the room.
They are totally uncontrolled in the bass region and even my Anthem STR struggles to cope with it.
My Arcam with DIRAC before that couldn't deal with it either. It was too much for the EQ to handle and I always ended up dissatisfied with the end result.
I can't even play them "full range" without some form of EQ because the bass just dominates the room and literally vibrates the whole room.
It's ridiculous really.
They do sound good though, I will say that and I'll probably miss certain aspects of their sound signature but they really do have to go.

Would the fact that the next set of speakers will be placed in the same, not ideal location and make the new speakers sound the same with the same room issues??

I'll chew over what you've said and post again... Thank you so much for your valued input!! :)
 
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Those Salk speakers in natural walnut (the colour I'm looking for) are beautiful by the way. Even the wife wasn't offended and that takes some doing as she's not interested in speakers...

Screenshot_20200927_181606_com.android.chrome.jpg

Lovely... :)
 

CDMC

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Wow..... I hope you don't mind but I need so time to digest all this info! :)

I will say that you've hit the nail on the head with regards to how my Spendors interact with the room.
They are totally uncontrolled in the bass region and even my Anthem STR struggles to cope with it.
My Arcam with DIRAC before that couldn't deal with it either. It was too much for the EQ to handle and I always ended up dissatisfied with the end result.
I can't even play them "full range" without some form of EQ because the bass just dominates the room and literally vibrates the whole room.
It's ridiculous really.
They do sound good though, I will say that and I'll probably miss certain aspects of their sound signature but they really do have to go.

Would the fact that the next set of speakers will be placed in the same, not ideal location and make the new speakers sound the same with the same room issues??

I'll chew over what you've said and post again... Thank you so much for your valued input!! :)

I haven't used ARC, so I don't know how to adjust it to make it work better for you. I calculate my filters using the EQ function in REW. I am not surprised by what you hear when running your speakers full range. Very roughly, try an -8db, q6.0, 40hz filter and see what it does if not running ARC. That should eliminate most, if not all of your big bass hump whether running your speakers full range or high passing them with the subs working on the low end.

In terms of new speakers, yes any speaker will stimulate that mode when placed in the same position, it is a question of how much. With an 80 24db high pass crossover, any set of mains that are flat down to 40hz should be down at least 24db by 40hz without room gain, and even with room gain, at least 18db, which should put their contribution below the level that they induce booming.

The next thing to look at is your subwoofers. You measured both independently, what are they showing? Where are they placed? Moving the subs around to optimize each is something you should also try. By doing so, you will likely see some smoothing of your room response (I am assuming you are measuring at you listening position). Here is a good article about multiple sub placement and benefits:

https://www.audioholics.com/subwoofer-setup/multiple-subwoofer-setup-calibration-1

I have attached photo showing the measurements of my left and right subs individually (red and blue), just like you and most others, I have a big peak in the 40hz range (mine is at 42hz). When you measure them together (green) that peak is still there, but the overall response is flatter, the 52hz suckout it also a room mode, there is no way to fix it easily, you can cut peaks, but boosting bass is problematic. Now throw in a narrow parametric cut at 42 hz and you get the purple line. Notice the 42 hz peak is gone and if you don't include the the room gain causing the bass in increase below 30 hz (this goes till 15hz and I adjust it out with my subs subsonic and low frequency cutoff switches) we are hitting +/- 4 db at the listening position in the bass range. I can play with placement and more equalization to get it flatter, but am pretty happy where it is.

Rythmiks living room.jpg



I strongly encourage you to play with your Mini DSP settings as I suggest and also subwoofer placement. I think this will help what you are hearing and get you a lot closer to what you want.
 

CDMC

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Those Salk speakers in natural walnut (the colour I'm looking for) are beautiful by the way. Even the wife wasn't offended and that takes some doing as she's not interested in speakers...

View attachment 85058

Lovely... :)

They look even better in person. The ones I had were Walnut, but stained with a bit of a reddish tinge. I would have preferred them natural, but I bought them used and for the $2200 I paid, was very happy.
 
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I haven't used ARC, so I don't know how to adjust it to make it work better for you. I calculate my filters using the EQ function in REW. I am not surprised by what you hear when running your speakers full range. Very roughly, try an -8db, q6.0, 40hz filter and see what it does if not running ARC. That should eliminate most, if not all of your big bass hump whether running your speakers full range or high passing them with the subs working on the low end.

In terms of new speakers, yes any speaker will stimulate that mode when placed in the same position, it is a question of how much. With an 80 24db high pass crossover, any set of mains that are flat down to 40hz should be down at least 24db by 40hz without room gain, and even with room gain, at least 18db, which should put their contribution below the level that they induce booming.

The next thing to look at is your subwoofers. You measured both independently, what are they showing? Where are they placed? Moving the subs around to optimize each is something you should also try. By doing so, you will likely see some smoothing of your room response (I am assuming you are measuring at you listening position). Here is a good article about multiple sub placement and benefits:

https://www.audioholics.com/subwoofer-setup/multiple-subwoofer-setup-calibration-1

I have attached photo showing the measurements of my left and right subs individually (red and blue), just like you and most others, I have a big peak in the 40hz range (mine is at 42hz). When you measure them together (green) that peak is still there, but the overall response is flatter, the 52hz suckout it also a room mode, there is no way to fix it easily, you can cut peaks, but boosting bass is problematic. Now throw in a narrow parametric cut at 42 hz and you get the purple line. Notice the 42 hz peak is gone and if you don't include the the room gain causing the bass in increase below 30 hz (this goes till 15hz and I adjust it out with my subs subsonic and low frequency cutoff switches) we are hitting +/- 4 db at the listening position in the bass range. I can play with placement and more equalization to get it flatter, but am pretty happy where it is.

View attachment 85067


I strongly encourage you to play with your Mini DSP settings as I suggest and also subwoofer placement. I think this will help what you are hearing and get you a lot closer to what you want.

This is why I've been so concerned about the new speaker purchase because they'll be going in the exact same place and don't want to excite that room mode again and waste yet more money on speakers. I want to buy and be happy that my subs are dealing with the low end and bookshelves will do the rest...

My subs together in room...
 
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Sorry. Wife wants to watch a film but I'll be back as soon as I can ...:)
 
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The subs I played around with for ages and I managed to find a decent position. My left sub is nearfield next to the couch and thd right sub is against the right wall near the right speaker.

The measurements are time aligned but with no EQ
 
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I watched "home theatre guru" on YouTube for the subwoofer info. Really helped me out.
 

CDMC

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Your sub measurements look really good to me. It looks like your starting to roll them off at about 60 hz which could be causing a hole in your response if you are high passing your mains at 80 hz. This will tend to make the 40hz peak sound worse. If you are not, try making sure your subwoofer crossover is disabled on the subwoofers themselves and cross your mains and subs at 80hz in Mini-dsp with LR 24db crossovers to start. If you are still getting the peak in the bass from your mains, increase their high pass to 36 db/oct or even 48 db/oct. You could also play a bit with frequency and move your mains high pass to 90hz at 24db/oct and see what that does.
 
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Your sub measurements look really good to me. It looks like your starting to roll them off at about 60 hz which could be causing a hole in your response if you are high passing your mains at 80 hz. This will tend to make the 40hz peak sound worse. If you are not, try making sure your subwoofer crossover is disabled on the subwoofers themselves and cross your mains and subs at 80hz in Mini-dsp with LR 24db crossovers to start. If you are still getting the peak in the bass from your mains, increase their high pass to 36 db/oct or even 48 db/oct. You could also play a bit with frequency and move your mains high pass to 90hz at 24db/oct and see what that does.

Yeah the subs playing together works quite well really considering how it was before! The peak at 60hz then subsequent dip is the room I'm afraid. The crossover is set to 80hz. I played around with the alignment feature of REW for quite a while and I even got help from a really experienced member of "AV Nirvana" who helped me align my subs and chose a suitable crossover.

He suggested that a 100hz crossover may work best so I've been playing around with it ever since and just settled of 80hz.

My subs sound awesome to be honest, I get deep, articulate bass at the MLP (not perfect either side of MLP but you can't have everything).

I really need to re-read everything you've wrote earlier as I'm desperate to select the correct speaker that won't activate that bloody mode at 40hz.

Considered the Song3 you suggested but the bottom firing driver may be firing into the side of my right sub so I'll have to discount that I think. Gutted because I love the look of it.

You definitely don't think the Revel M126be would be a good choice?
 

CDMC

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Yeah the subs playing together works quite well really considering how it was before! The peak at 60hz then subsequent dip is the room I'm afraid. The crossover is set to 80hz. I played around with the alignment feature of REW for quite a while and I even got help from a really experienced member of "AV Nirvana" who helped me align my subs and chose a suitable crossover.

He suggested that a 100hz crossover may work best so I've been playing around with it ever since and just settled of 80hz.

My subs sound awesome to be honest, I get deep, articulate bass at the MLP (not perfect either side of MLP but you can't have everything).

I really need to re-read everything you've wrote earlier as I'm desperate to select the correct speaker that won't activate that bloody mode at 40hz.

Considered the Song3 you suggested but the bottom firing driver may be firing into the side of my right sub so I'll have to discount that I think. Gutted because I love the look of it.

You definitely don't think the Revel M126be would be a good choice?

I think the M126be is a great speaker and would likely work well for you. I also think you have the tools already to stop your current speakers from causing the issue the you are having in the bass. Increase the crossover slope to 48db an octave and see how it works. This is one of the great things about digital crossovers, you have options. First see how that works and then consider if you are still worried about a floor standing speaker causing you issues. Also, how loud do you listen? Can you share some photos of your room and listening setup?
 

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Aesthetics are a big consideration in speaker choice too. They are in a lounge/living room which means they have to look the part and blend with the surroundings. We have walnut furniture so the speakers must also be walnut (any other colour just looks odd) so this limits choice too as not all speaker manufacturers make a walnut cabinet.
They also have to pass the WAF aspect. The Revels certainly tick that box in spades.

If I had a man cave, things would be different but this is the situation I'm in so have to go with what's available. It may turn out that the speakers I have now are the perfect ones for my room but I just want to try something different so I can experience the sound of Revel and make an informed choice.
My wife wasn’t happy when I dragged in a pair of Kplisch Forte IIIs into our family room, but she got over it. Words to live by- it’s easier to ask for forgiveness than to ask for permission :p
 

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My wife wasn’t happy when I dragged in a pair of Kplisch Forte IIIs into our family room, but she got over it. Words to live by- it’s easier to ask for forgiveness than to ask for permission :p
AMEN. I never owned a very large home with extra "family rooms" and such so the living room was MY space, take it or leave it. A 22 x 14 x 9 room, I had the listening/viewing chair ruffly in the middle of the room, when it faced North down the long dimension it looked at my 2ch rig with Klipsch LaScala's and dual 7' tall HSU subwoofers with the gear shrine in the middle. When I swung the chair to the south, it faced my 35" Mitsubishi CRT TV and a 5.2 Paradigm surround speaker system that would also use the same HSU subwoofers, an Adcom HT pre/pro and Adcom GFA amps. It was a great little multich system in it's time. All that ended after my retirement in 2008 and my move to paradise in Central FL.
As B B King alway sang,
"as long as I'm payin the rent and the bills woman,
I'm payin the cost to be the boss" ;)
 
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Morning chaps.

I'm off to work now but will be back later.
I'll leave you all with some pics of my modest living room. Standard, small english living room with "not ideal" location issues.

As you can see, my speakers are in the corner (this cannot be changed) my right sub is about 2 foot from the right speaker.
My left sub is next to the couch with a glass plate on with sorbothane pads to prevent vibration into the lamp.
MLP is not ideal as my window is directly behind.

The cardboard boxes are some Focal 906's I'm selling. Tried them out but the wife hated the stands.
They sounded nice actually but didn't have them set up long enough to provide an accurate, subjective account of them.

See the walnut theme.... This must continue with the new speakers (if I buy new speakers)

I tried to plug the ports of the Spendors but it only drops the 40hz mode by around 4db.

Anyway, off to work..... IMG_20200928_085915.jpgIMG_20200928_085924.jpgIMG_20200928_085934.jpgIMG_20200928_085941.jpgIMG_20200928_085947.jpgIMG_20200928_085958.jpgIMG_20200928_090009.jpgIMG_20200928_090021.jpgIMG_20200928_090035.jpg
 

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vavan

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I can't upload my true MDAT for some reason
if the reason was the site engine didn't allow it just zip .mdat before uploading
 
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Oh, I generally listen at around 70db but when a film is on I bump it to around 85.
Music is dependent on song but generally around 85-90 when I'm really into it... :)
 
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if the reason was the site engine didn't allow it just zip .mdat before uploading

Ah....... I'm using my phone for most of this but I'll sort that when I get home from work...
 

Willem

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I am not quite sure what your problems are: if it is a harsh sound, the main speakers would be the prime suspect. However, if it is a 40 Hz peak, it pays to do a little experiment: just turn off the subs, and measure again (with high pass filter and any dsp eq of the main speakers still activated, i.e. no other changes). Is the peak gone, or not?
My hunch is that with respect to bass response you are trying to pump too much bass into a room that is too small for it.
 
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