A Message from a "Bass Head"

[dasdoing]

Señorita is a recent pop song example that will have deficiencies without the below 40Hz material. Not the refrain (goes low, but should still sound good), but the bridge. check out the bridge on that one. personaly I could live with 33Hz, but 27Hzish (covers A0) is nice to have

 

[ernestcarl]

... reference level, which is calibrated at 80db for -20db lufs, so potentially 100db peaks, but usually much lower as I use volume leveling to -20db.

I have no idea how accurate my UMIK-1 is with its calibration file, but true transient peaks for bass frequencies actually go higher than the expected point when set at your relative reference level. For the most part, extreme peaks probably don't register perceptually as such to the brain as they are quite short/transient in nature anyhows.

I've been doing some tests lately, and even with a single Rythmik F12 sub (room gain in my case helps a lot) there is actually more room for transient peaks than I expected. Note: I already checked to see if my DAC has enough headroom in case of peaks over 0dBFS, and it's all good.

I read 112dB peak from just a single F12 sub measured at the listening position ~3.5m away -- no speakers -- with speakers ON and overlapping with the sub, transient peak reaches 116dB. Sub was playing cleanly (perceptually) and in no way bottoming out -- I should know as I was sitting right in front of the sub (if both main speakers were playing, those would be the ones to distort more with heavy bass).

Disregarding the test tones/noise, I can still get similar results with extreme high SPL music tracks with corresponding extreme peaks:

L&R S8 SPEAKERS + single F12 SUB - 'Forward' EQ preset

Measured at MLP in couch where speakers are 2m away and sub is 3.5m away.

To be fair, I have a relatively small room...

Oh, and like you, I never listen this loud for more than a few minutes. This was just for testing...

 

[Willem]

The Quad 2805 speakers in my main system do not go much below some 35-40 Hz, so I added a subwoofer. This made the sound much more realistic with full output to below 15 Hz, but also showed the problem of reproducing low frequencies, even in a large (about 75 sqm) room: the sound was woolly and slow to the extent that I had to turn down the subwoofer so much that it was hardly worthwhile having one. I then discovered about room modes and bought an Antimode 8033 dsp room eq unit for the sub, and this largely cured the problem (next step will be a second sub). So yes, subs are great but also create real problems that cannot be ignored.
The desktop system in my study faces a different environment of only some 18 sq m. Here, the speakers are Harbeth P3ESRs that only go down to some 75 Hz. I love them, but bass is clearly lacking. I experimented with a borrowed small REL subwoofer, but the sound remained woolly and imprecise. My conclusion is that this room with its much higher Schroeder frequency is just too small for deep bass. Interestingly, I also experimented with these small speakers in my main system with the sub in the main listening room, and here the sound of these litle bookshelves supported by the equalized big sub was spectacularly good, even though really high SPL levels from these small speakers remained impossible in this big room, of course.
So my conclusion is that for proper full range sound you certainly need (multiple) subwoofers, but also some dsp room eq. However, this will only work well in a good sized room. In a smaller room you may be better off without the really deep bass.

 

[dasdoing]

If one has the money, this is the only effective thing against room modes other than heavily treating the corners
https://www.psiaudio.swiss/avaa-c20-active-bass-trap/

would be an idea for Armin to test

 

[tmtomh]

If one has the money, this is the only effective thing against room modes other than heavily treating the corners
https://www.psiaudio.swiss/avaa-c20-active-bass-trap/

would be an idea for Armin to test

Fascinating! Hard to tell exactly how it works, but it appears to be some kind of bass speaker or passive radiator that inverts the phase of in-room low frequencies based on how strong they are when they hit the unit, yes?

But wow - $5500US for a pair - that's some expensive room treatment.

 

[dasdoing]

Fascinating! Hard to tell exactly how it works, but it appears to be some kind of bass speaker or passive radiator that inverts the phase of in-room low frequencies based on how strong they are when they hit the unit, yes?

"A microphone will measure the acoustic pressure in front of an acoustic resistance.

The acoustic resistance is designed to let air through but reducing significantly the pressure.

Behind the acoustic resistance, a transducer membrane is driven to absorb the volume of air going through the acoustic resistance as well as ensuring a specific acoustic impedance in front of this acoustic resistance.

When in function, this acoustic impedance in front of the acoustic resistance is significantly lower than in ambient air and therefore acts as a pressure sink.
The acoustic impedance of the air is affected typically over a radius of 1 to 1.5 m around the AVAA. This explains how the AVAA can be more absorbent that its actual surface of perfect absorber."

But wow - $5500US for a pair - that's some expensive room treatment.

worse, you probably want 4 of them. read (google) what mastering star Bob Katz has to say about them.
but then again it's those things in the 4 corners vs having 4 corners and backwall fully treated with lots of material. for those who need permission form wife they are probaby the only option to have a fully bass treated room

 

[Willem]

I don't remember for now where but I have read a review somewhere with measurements: the effect was small, and not really worth the money. I think multiple subs combined with dsp room eq is the best solution if massive bass traps are not acceptable.

 

[Archsam]

When I am in the mood for bass these days, I turn off my stereo and put on my Audeze LCD-X.

I am friendly with my 3 neighbours flanking my flat and I like to keep it that way

 

[Aerith Gainsborough]

When I am in the mood for bass these days, I turn off my stereo and put on my Audeze LCD-X

Yes, if we want to keep good relations, there is not much alternative.

Though I can't really complain that much. With Dirac Live my lil' Aria 906 go down to 36Hz until they fall off a cliff (30Hz @ -12dB ). Sounds nice and full enough.

Also very interesting perspective @Willem . Thank you for sharing your "small room experiences". One more argument against a sub for me.

 

[dasdoing]

I don't remember for now where but I have read a review somewhere with measurements: the effect was small, and not really worth the money. I think multiple subs combined with dsp room eq is the best solution if massive bass traps are not acceptable.

could it be Bob Katz's review was payed? what a shame

 

[shal]

I have read that if harmonics are present and not the fundamental , the brain add himself the fundamental and did not notice its absence .

So with a good 80hz you can have a good reproduction of 40-80Hz sound ... if it's sound with harmonics of course

I have 15inch (one by speaker ) so , yes...i love bass

 

[dasdoing]

about neighbours, it's actualy the modes that most transfer through the walls, if played at normal level. so the better you treat, the happier the neighbour. it's even worse with neighbours below and over you, since those rooms will have the same modes which are then exited by your modes which pass trough.

 

[Aerith Gainsborough]

about neighbours, it's actualy the modes that most transfer through the walls.

It's not just the modes, no.
Low frequencies are not attenuated much by the normal building materials. If I generate 110dB @ 20Hz, most of that will go through to any neighbor. Worse, if your sub actually uses the construction to generate vibrations to make you feel the bass (downfire sub).

It is really difficult to contain low frequencies, that's why you can hear the subwoofer of a car driving by clearly and loudly, even if your windows are closed.

 

[dasdoing]

It's not just the modes, no.
Low frequencies are not attenuated much by the normal building materials. If I generate 110dB @ 20Hz, most of that will go through to any neighbor. Worse, if your sub actually uses the construction to generate vibrations to make you feel the bass (downfire sub).

It is really difficult to contain low frequencies, that's why you can hear the subwoofer of a car driving by clearly and loudly, even if your windows are closed.

to low frequencies pass through concrete/brick it has to make it vibrate., so there is so much energie necessary.
to isolate low frequencies you need mass. however, the modes are the loudest, and they ring "eternaly". you can imagine how that makes the mass vibrate easier.
make a test. play your 20Hz at 50dB and see how far it goes. 110dB @ 20Hz will obviously pass to even half a meter of concrete.
you can't realy compare to a car, there is very few energy necessary to pass that thin material.
also, it depends on the walls. US walls are very low mass (because of earthquakes?). dubble brick walls are much more isolating then those

 

[Willem]

I don't remember for now where but I have read a review somewhere with measurements

I am not sure if this is the review, but this is from a German dealer's website: https://www.mbakustik.de/wp-content/uploads/AVAA-Test.pdf Small but useful improvements., particularly in untreated rooms.

 

[dasdoing]

I am not sure if this is the review, but this is from a German dealer's website: https://www.mbakustik.de/wp-content/uploads/AVAA-Test.pdf Small but useful improvements., particularly in untreated rooms.

you realy need to see graphs with time domain (watterfalls), because they act manly in the ringing. here are some prety good meassurements: https://www.gearslutz.com/board/stu...st-results-psi-avaa-c20-active-bass-trap.html

I would only buy this stuff if buying 4 woudn't hurt my wallet though lol

 

[Aerith Gainsborough]

play your 20Hz at 50dB and see how far it goes

Erm.. why should I care about inaudible levels of a given frequency?
If you use it to play music you need higher levels or you won't hear a thing.
You can start hearing it at 80dB but 100 dB peaks are more realistic.
These will automatically be shared with your neighbor. Simple as that and there is little you can do about it but hope he does not mind / play at uncritical times of day or when he is away.

 

[Archsam]

The construction of homes in the UK might actually explain a thing or two about British speakers such as the LS3/5A and other sealed box speakers that don't go very deep in bass.

What you see as lovely British terrace houses in TV and movies were originally standard townhouses (North American terminology). Just like their American and Canadian counterpart, these are masonry and timber construction e.g. the party wall separating adjacent houses are usually masonry e.g. concrete blocks, they are load bearing walls that also double as fire separation between houses, and the floor and roof construction is timber joist and timber floor board with plasterboard ceiling to the underside. The void between the joist are filled with batted insulation for sound.

A lot of these houses are build over 100 years ago and onwards. But fast forward to the 70s and 80s, particularly after Margaret Thatcher started pushing for privatisation of council flats to promote private home ownership, real estate prices skyrocketed and the market started converting these old houses into flats - what used to be a 2 storey townhouse is now converted into 2 flats. And the spearation between upstairs and downstairs neighbours is the same 1 inch tongue and groove floor boards (and I will stress the term 'groove' here, as there are lots of them) with a single layer plasterboard below. Anyone living in a house in American and Canada will know what i mean, you can hear everything through the ceiling upstairs, worse if the house is getting old and the floor board starts creaking.

My flat where I live now was originally a grand mansion house build in 1910s by a former British MP . In the 80s it was converted into 5 separate flats, including a loft conversion to turn the pitch roof zone into flat no. 5. So I am flanked by 3 neighbours (up / down / side) with timber floor construction separating my upstairs and downstairs neighbours. My Harbeth P3esr produces nothing below 75hz and even then I am very careful with the volume of music I play. Playing big, deep bass is just about impossible.

So until i can afford a million pound detached house far from the city centre, small bookshelve speakers will have to do.

 

[Willem]

UK homes also tend to be tiny with tiny living rooms, compared to the US, but also compared to the Netherlands. So deep bass is unrealistic in any case. UK housing stock is also relatively old and often does not meet any modern construction standards.

 

[ernestcarl]

I have no idea how accurate my UMIK-1 is with its calibration file, but true transient peaks for bass frequencies actually go higher than the expected point when set at your relative reference level.

Actually, my math is probably quite off. While I would never be playing at full 0dBFS normally, anyway... if, let's say, I keep the level there at maximum and apply no attenuation. Some of the overs would inevitably be compressed or clipped anyhow.

I measured an extreme 112dB peak at 2 meters. In a 1 meter distance, that would be around 118dB! The limit of the speakers is written as ~116dB max peak SPL at 1m (for a single monitor) in the manual, and so the upper limit has already been reached. I wrote ~98dB was measured at 2 meters (MLP) when the miniDSP was left at 0dBFS and generating a full scale pink noise signal. 98+20 should be potentially equal to 118dB, but I only measured a 112dB max peak... okay, the drivers, amp and/or DAC very likely can't really go anymore above that... It was only in combo with the sub, pushed at its own very limits, that the mic even registered 116dB