$30K Budget - On the quest for my "end game" speaker

[Absolute]

In my experience the audibility of subwoofer location depends on crossover frequency, crossover slope, placement of subwoofer, timing, level of spl relative to the mains and room interaction (it might create vibrations in floor, walls, furniture etc).
Based on my own testing with two subs placed in all different kinds of places I'd say that the further away from the fronts the sub is located, the less freedom you have in regards to crossover, spl and careless timing.

Geddes' approach where you're starting with sub 1 closest to mains with highest spl and gradually decreasing level (crossovers also?) seemed to work okay for me with regards to localization issues. I did find that placing a sub next to the couch made it difficult to keep "invisible" in all seats when crossed at above 60-70 hz.

All that said, my experience with a double bass array where the woofers on the back wall worked up to around 120 hz was nothing but extra-ordinarily positive. Absolutely no chance of localizing or hearing anything other than magnificent bass everywhere with the mains providing all localization cues and phase information. This experience made me a believer of the bass = room philosophy.

 

[MKR]

I sincerely apologize for how that came across, implying that was not at all my intention. Searching for the graph of Dunning-Kruger gave this result which I found funny in a side-poking kind of way.
In hindsight I should have been more mature and chosen a different version of the graph and be more careful of my wording to make sure the implication was not to call anyone stupid (or uneducated). Apologies to @MKR And the rest of you.

All good sir, I knew what you meant by this, and I took no offense whatsoever, no apology needed

 

[Absolute]

All good sir, I knew what you meant by this, and I took no offense whatsoever, no apology needed

I'm relieved to hear that.

 

[gnarly]

Gnarly, indeed.

Lol (re A for Ara) I take it you don't like the looks.....???
If so, are you one of those guys who hears with his eyes too?

Seriously though, I've followed Cowan's work on DIY for quite a while...he does brilliant electro-acoustic designs and is a generous and respected contributor.
(A link to the Stereophile article on DIY is the only reason i knew the article existed. Article was mainly poetic crap imo)

My proclivity is DIY MEHs....which when well done, continue to fit my aural preferences and best any type speaker I've heard. My ability to make the MEH horns is limited to straigh sided conical walls. No so for A for Ara, which can make curved horns, that supposedly provide reduced mouth termination issues, and smoother off-axis curves.
So its for SQ alone I would opt for the first model shown in Stereophile. They make some much larger boxes that I imagine sound better and would be my real first choice.
I'm the kind that listens only with my ears.....

 

[Duke]

In my experience the audibility of subwoofer location depends on crossover frequency, crossover slope, placement of subwoofer, timing, level of spl relative to the mains and room interaction (it might create vibrations in floor, walls, furniture etc).

Back when I designed the "Swarm" four-piece subwoofer system I did some investigation and experimentation to find practical limits for subwoofer crossover frequency and slope. Not being interested in investing the megabucks to have a custom subwoofer amp made, my focus was on finding an off-the-shelf solution. Since the distributed multi-sub paradigm I subscribe to often involves one or more subs placed to the side of or behind the listening position, keeping those subs in particular from being audibly localizable with program material is vital. (Localizable with test tones is imo permissible.)

Fourth-order was clearly better than second or third order (which narrowed my amplifier choices), and the upper crossover frequency with a fourth-order lowpass filter seemed to be about 100 Hz. To play it safe, I recommend to my customers crossing over no higher than 80 Hz.

I don't remember ever having a customer complain about the subs being localizable, and this includes a customer who places one of his Swarm units directly behind the listening chair. So based on my experience, I suggest running the subs no higher than 80 Hz and using a 4th-order lowpass filter. Presumably a shallower slope filter can be used if the crossover frequency is significantly lower than 80 Hz, but I don't know what those practical limits would be.

 

[Absolute]

Localizable with test tones is imo permissible.

Thank you for sharing your experiences. I think this sentence is the key here. Once you decide to isolate every sub and/or play test tones through the subs it's a different ballgame. No problems localizing a 80 hz lr24 crossed sub when it's playing alone. Once integrated to the mains and all of them are playing normal signals it becomes much harder.

 

[Kal Rubinson]

Lol (re A for Ara) I take it you don't like the looks.....???

Yup.

If so, are you one of those guys who hears with his eyes too?

Nope but I would prefer that the underlying design had been expressed otherwise.

 

[petezapie]

In my experience the audibility of subwoofer location depends on crossover frequency, crossover slope, placement of subwoofer, timing, level of spl relative to the mains and room interaction (it might create vibrations in floor, walls, furniture etc).
Based on my own testing with two subs placed in all different kinds of places I'd say that the further away from the fronts the sub is located, the less freedom you have in regards to crossover, spl and careless timing.

Geddes' approach where you're starting with sub 1 closest to mains with highest spl and gradually decreasing level (crossovers also?) seemed to work okay for me with regards to localization issues. I did find that placing a sub next to the couch made it difficult to keep "invisible" in all seats when crossed at above 60-70 hz.

All that said, my experience with a double bass array where the woofers on the back wall worked up to around 120 hz was nothing but extra-ordinarily positive. Absolutely no chance of localizing or hearing anything other than magnificent bass everywhere with the mains providing all localization cues and phase information. This experience made me a believer of the bass = room philosophy.

I agree, for me getting the phase settings correct for my two subs was critical. Like bringing binoculars into focus, when set properly it connects the lower octave to the main image eliminating that sense the subs are disconnected and locatable.

 

[benanders]

I’ve been curious for some time about a purported negative relationship between driver size and soundstage: smaller drivers generating a more expansive soundstage, as it relates to LF.

The flip side of this would be the argument of lower visceral impact from multiple small drivers of equal surface area to a large driver(s), again for LF.

Seems relevant enough with things veering towards subwoofers.

 

[benanders]

By the way, another interesting post on the sub freq cutoff topic …

https://audiosciencereview.com/forum/index.php?threads/jbl-4367-review-was-m2-review.190/post-5521

A quick glance seems, if nothing else, further suggestion for your ears to give JBL’s a go, eh?

JBL 4367 Review (was M2 'review')

AJ so what is the 'ideal' solution? Keith.

www.audiosciencereview.com

…that’s a pricey claim!

 

[Laserjock]

Here would be my choice for $25,000

Brilliant Corners #3: On the Horns of a DilemmaA for Ara speakers, the Lejonklou Källa streaming DAC

The Amtrak Empire service snakes north along the Hudson River before reaching Albany, where it pitches sharply to the west, eventually winding up in Niagara Falls. In November I rode itthe Amtrak Empire service, not Niagara Fallsfrom New York City to the town of Hudson, New York. On my left, the...

www.stereophile.com

After reading some,
I had to look and see if that was posted on April 1st.

 

[Bjorn]

but my conclusion is that if a speaker requires EQ and room treatment to sound right, it is a flawed design to begin with. Thoughts?

I assume you are talking about EQ of the room response and not EQ of the speaker alone. After all, speakers do need EQ and which is done either in the passive or active crossover.

With this in mind, you ask a valid and important question. EQ of the room response will almost always comes with some kind of compromises. Raising low frequency dips wil for instance increase distortion. Reducing low frequency peaks with many dBs will often reduce dynamics and make the response worse in other parts of the room. And neither of these deal with the harmonics of the frequency one is addressing. Most of the room response isn't minimum phase behaviour, meaning the phase will not follow when the frequency is changed. This will lead to phase distortion. How audible that is very much depends, but generally is much more audible for midrange and treble than lows.
However, using shelving to tailor the response to the room/placement and music taste without doing anything with dips and peaks is fine. And it's also needed considering we listen at various distances and have different reinforcement from the boundaries.

Room treatment doesn't suffer from the compromises EQ has and actually makes the room response more minimum phase as long as the treatment is of high quality. As long as we are listening with boundaries, the room will effect the sound quality greatly no matter how good the speakers are. Naked paralell surfaces will create flutter-echo and comb filtering. The close proximity of boundaries create standing waves. Especially the important time domain behaviour and certain psycoacoustic cues can only be improved with physical treatment.

That being said, speaker design react differently in rooms. You can take two different speaker designs, and one will measure considerably more even than the other. And while treatment can get them closer, some room interaction isn't easily treatable. For example the floor bounce. Thus a great speaker design will take the room into consideration and that's always where we want to start. Creating problems that needs to be fixed later is never optimal.

So with that in mind, there are speaker designs that are to some degree "flawed" or of less quality. Many of the speakers that we see scoring high in spinoramas are in my opinion quite mediocre. Place them in a room, and the response in part of the frequency range will not be particular even and there are other issues like intermodulation distortion and thermal distortion. Fixing uneven response with "room correction" doesn't work very well, and the distortion issues can't be solved either. Correcting parts of the uneven response with treatment is difficult and sometimes impossible.

So start with the very best speaker design and desired beamwidth, treat the room as well as possible, and use EQ to tailor the general response by listening. Most likely you are not going to need the multiple subwoofer approach or EQ in the lows to achieve a flat bass response with the combination of optimizing placement and room treatment in such a room.

 

[MKR]

I assume you are talking about EQ of the room response and not EQ of the speaker alone. After all, speakers do need EQ and which is done either in the passive or active crossover.

With this in mind, you ask a valid and important question. EQ of the room response will almost always comes with some kind of compromises. Raising low frequency dips wil for instance increase distortion. Reducing low frequency peaks with many dBs will often reduce dynamics and make the response worse in other parts of the room. And neither of these deal with the harmonics of the frequency one is addressing. Most of the room response isn't minimum phase behaviour, meaning the phase will not follow when the frequency is changed. This will lead to phase distortion. How audible that is very much depends, but generally is much more audible for midrange and treble than lows.
However, using shelving to tailor the response to the room/placement and music taste without doing anything with dips and peaks is fine. And it's also needed considering we listen at various distances and have different reinforcement from the boundaries.

Room treatment doesn't suffer from the compromises EQ has and actually makes the room response more minimum phase as long as the treatment is of high quality. As long as we are listening with boundaries, the room will effect the sound quality greatly no matter how good the speakers are. Naked paralell surfaces will create flutter-echo and comb filtering. The close proximity of boundaries create standing waves. Especially the important time domain behaviour and certain psycoacoustic cues can only be improved with physical treatment.

That being said, speaker design react differently in rooms. You can take two different speaker designs, and one will measure considerably more even than the other. And while treatment can get them closer, some room interaction isn't easily treatable. For example the floor bounce. Thus a great speaker design will take the room into consideration and that's always where we want to start. Creating problems that needs to be fixed later is never optimal.

So with that in mind, there are speaker designs that are to some degree "flawed" or of less quality. Many of the speakers that we see scoring high in spinoramas are in my opinion quite mediocre. Place them in a room, and the response in part of the frequency range will not be particular even and there are other issues like intermodulation distortion and thermal distortion. Fixing uneven response with "room correction" doesn't work very well, and the distortion issues can't be solved either. Correcting parts of the uneven response with treatment is difficult and sometimes impossible.

So start with the very best speaker design and desired beamwidth, treat the room as well as possible, and use EQ to tailor the general response by listening. Most likely you are not going to need the multiple subwoofer approach or EQ in the lows to achieve a flat bass response with the combination of optimizing placement and room treatment in such a room.

Thank you very much, really appreciate your thoughts, this is where I was trying to go with my question (though of course your knowledge of acoustics far exceeds mine and never could I have stated my position in such a way, thanks for standing in for my little brain ). And indeed, I was referring to room EQ. Though I would also say if a speaker requires significant intrinsic EQ AFTER the designer has finished their duty, that should be considered a flawed design. But yes, no speaker is perfect and even the best designs can benefit from some EQ.

As to the multi-sub approach potentially not being needed (with correct placement and room treatment), this is also something I have been very curious about and am leaning in a similar direction per my recent research.

Thanks again @Bjorn !

 

[Bjorn]

Thank you very much, really appreciate your thoughts, this is where I was trying to go with my question (though of course your knowledge of acoustics far exceeds mine and never could I have stated my position in such a way, thanks for standing in for my little brain ). And indeed, I was referring to room EQ. Though I would also say if a speaker requires significant intrinsic EQ AFTER the designer has finished their duty, that should be considered a flawed design. But yes, no speaker is perfect and even the best designs can benefit from some EQ.

As to the multi-sub approach potentially not being needed (with correct placement and room treatment), this is also something I have been very curious about and am leaning in a similar direction per my recent research.

Thanks again @Bjorn !

Another thing to point out about applying EQ is that part of the speaker response isn't minimum phase behaviour either and there are areas here that simply cannot be effectively equalized. It will in many cases make things worse.

Even in quite challenging small rooms, it's often possible to achieve a very even low frequency response by simply positioning speakers and listening position optimal. We move out of the room modes. This is easier with a separate bass solution, and lower distortion is also achieved with a separate solution. However, if the goal is have an even response in most of the room, this would require a lot of surface treatment.

 

[Absolute]

It's hard to disagree with what Bjorn writes. To me the multi-sub approach is just an alternative to room treatment with the aim of achieving a nice and even low-bass response over a large area. Room treatment will potentially have a much wider benefit-range than multi-sub, but multi-sub will potentially solve capacity issues in the low range and might free speakers of needless distortion. Those things are not mutually exclusive - and I would argue to consider both for both practical and qualitative purposes.

I understand the concept of wanting to decomplicate stuff in order to see a clear path towards the goal, but be careful to not over-simplify when trying to define what you need to do in order to reach the destination you want. Not knowing what you want is also a certain way to not get there.

Low frequency reproduction is the most important factor for subjective sound quality, so consider already in the planning stage how you aim to achieve a nice response over the desired area and how to keep the decay under control. If you decide that the Salon2s' (my guesstimate for your destination) provide all the bass that you need, but you want a nice and even response over a certain area it's probably a good idea to think about including the room's construction itself as part of the low frequency treatment in one way or another. Especially if you want the room to look nice as well as play nice.

 

[Bjorn]

Just to be clear. When I'm referring to the multiple subwoofer approach I'm talking about randomely placing three or more subwoofers working at the same frequency area in the room with the goal of achieving an even response.
I'm not talking about simply using several subwoofers in order to get lower distortion and reach necessary SPL. The latter is something I find crucial for a high-end setup unless one is using one subwoofer with super high SPL (like a hugh horn subwoofer).

In regards to capacity I'm not really sure multiple subwoofer approach where one or two are placed in the opposite direction works that well. My experience is that this approach leads to a lack of slam and tactile experience compared to having all in the front pointing in the same direction. Perhaps because they end up partially working against each other.

 

[Absolute]

I see. I define every multiple bass source concepts as multi-subs as a generic term, not specifically the randomized stuff.
The reason for that is that any given multiple sub setup with flat response will give about the same rate of decay within the first few hundred ms in the lower frequencies - if I recall the conversation with Geddes correctly. It's been a few years.

A few questions to the experts here;

1. I assume a flat frequency response with the same roll-off in the low frequencies will give the same phase response regardless of how you get there. Wrong?

2. I assume you can have the same phase response but with different step response. Wrong?

3. Assuming this is both true, is it wrong of me to then assume that at least one of those can't be very audible at low frequencies?

 

[Theogenes]

No interest in Barefoot, but thanks for the recommendation!

Coming into this thread late, I know.

I was in a similar spot a couple of years ago (except I'd already zeroed in on active speakers). I spent several hours demoing at Vintage King (I'm in the US), and listened to the Kii Three, ATC SCM150A (I'm a big ATC fan and already have a set of smaller active monitors and a HT setup of passives), a few others, and the Barefoot MM27 and Barefoot MM12. For me, although the ATCs were fantastic and could have easily made me very happy, the MM12 was clearly the most impressive overall. (I listened to just the speakers without the additional bass modules). I got the MM12s and have been absolutely delighted ever since. They have the added benefit of working (exceptionally well) in the nearfield as well, so the usable listening area is quite large.

They are not innately beautiful speakers as many of the hifi recommendations would be, so if that's the reason you're ruling them out it makes perfect sense. If you're interested in performance above all else, I'd humbly recommend at least giving them a listen. I didn't even have them on my radar when I went in to audition (I was extremely interested in the Kii Three and ATC 150), but I realized that for me, they were essentially perfect.

Not trying to undermine any decisions you've made, just hopefully providing some additional data points that might be helpful to you or others in the future.

Only other recommendation might be the Geithain. I have a single RL903K (long story), and it sounds absolutely excellent as well.

Good luck on your search!

 

[UCrazyKid]

with $30k I would go shopping for some Børrensen Audio speakers.

 

[Holmz]

Another thing to point out about applying EQ is that part of the speaker response isn't minimum phase behaviour either and there are areas here that simply cannot be effectively equalized. It will in many cases make things worse.

…

@Bjorn how much do you weigh the time domain response?
I am assuming that frequency domain can be largely fixed with DSP - but I am not fully comprehending the minimum phase part you mentioned.