The Bass is the place!!

You can get accurate, extended bass, it just doesn't easily come in small packages or small rooms.

DaveyF said:

Perhaps, but how accurate is it, really?

Certainly in small rooms (BTW, how are we defining 'small rooms'?) it is exceedingly difficult. IME, the extension to, at or below 20hz ,in a small room is almost impossible.
In my small room I can just about generate 35Hz with 'reasonable' accuracy. However, there is still a lot of info below 35hz and I believe the lower the number, the harder it is to get 'accurate' and
'defined'. I suspect that a lot of us think we are getting great bass ( see my description in my OP)...down to 20hz and below, when in fact we are not!

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There are ways, not by ear alone, and usually not without subwoofers to get excellent bass down to 20Hz and below, even, if that is something you want. I am quite confident that I have it down to 18 or so Hz. I do not need more frequency extension than that.

If your ears tell you you are not getting 20Hz bass, but a measurement mike says you are, which is right? Sorry for bringing that up. Your ears are always right, and measurements are always wrong, as we know.

GaryProtein said:

You can get accurate, extended bass, it just doesn't easily come in small packages or small rooms.

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That is an excellent point. People talk about not needing treatments in larger rooms, but if the room is too large (or you are listening outside), the bass sucks also...

The room defines the bass ... so to get accurate bass at listening position .. no matter what the speaker .. you have to treat the room , position the listening chair properly and use DSP
Problem with big speakers is that the positioning for mids/treble/imaging is oftern not ideal for the bass side
I get exceptional bass in my 8m x 6m room...
How did I gret there

Well I have 4 massive subs and speakers capable of outperforming the subs

The 4 subs are used in a toole/geddes/welti arrangement in that they destructively drive nodes ..IE they dont give much more bass , but are used to smooth the rooms bass response
To do this I use DSP on all 4 subs
Thereafter , I tackle the mains and the subs by using DIRAC to see the system as a whole
I tweak by ear after
the room is treated with some bass traps , but they cannot in any way handle the huge peaks in the room .. only DSP can

I'd say it like this: you need speakers (or subs too) that offer the capability to produce bass at the frequencies you desire AND the ability to play LOUDER than you may wish. In this manner, you may apply room correction (which often cuts the signal) and still have acceptable output levels.

Lee

Love the tagline Davey. Put a smile on my face .

As Rodney said, the room is the #1 problem in bass. The speaker plays a minor role in how good it is, until you fix the room. Then you get to hear the nature of the bass from the speaker itself. Here is the measurement of how bass varies in each seat in a room: http://www.audiosciencereview.com/forum/index.php?threads/subwoofer-low-frequency-optimization.15/



Just moving 3 feet causes a large change, proving this is a room effect, not speaker. And that change 100% matches the subjective terminology you use. Boominess comes from exaggerated notes when those peaks occur. And in time domain, they cause ringing which adds insult to injury by extending said boomy notes.

Unless measures are taken with careful positioning of the speakers, listening position, EQ, treatment, subs, etc., you are guaranteed to have bass problems. It doesn't matter if you have $500 subwoofer for the $104,000 new ALEXX speaker from Wilson which despite being in a large conference room at AXPONA, it still sounded boomy.

This is not to say that the speaker doesn't matter. Once you peel the effect of the room, then you start hearing the low frequencies from the amp and speaker. If it bottoms out, gets distorted, these are things you need to fix but not before the room.

RBFC said:

I'd say it like this: you need speakers (or subs too) that offer the capability to produce bass at the frequencies you desire AND the ability to play LOUDER than you may wish. In this manner, you may apply room correction (which often cuts the signal) and still have acceptable output levels.

Lee

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Excellent simple explanation

As Rodney said, the room is the #1 problem in bass. The speaker plays a minor role in how good it is, until you fix the room.

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Hello Amir

I don't agree as I see it both the room and the speakers in equal measure. I don't care how good your room is if the speakers bass response is peaked or irregular it is going to be an issue. You also have to look at the low frequency extension and power handling . If the system can't do what you need it's all a moot point. You need to have a speaker up front that can do what you need placement comes second. Having a treated room doesn't fix everything there is no magic bullet.


Hello

If your ears tell you you are not getting 20Hz bass, but a measurement mike says you are, which is right? Sorry for bringing that up. Your ears are always right, and measurements are always wrong, as we know.

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I think you have that flipped You can easily measure 20Hz and not hear it, all depends on the SPL. At those low frequencies you need quite a high level signal to hear it. Go checkout the Fletcher Molson curves.

Rob

amirm said:

Unless measures are taken with careful positioning of the speakers, listening position, EQ, treatment, subs, etc., you are guaranteed to have bass problems. It doesn't matter if you have $500 subwoofer for the $104,000 new ALEXX speaker from Wilson which despite being in a large conference room at AXPONA, it still sounded boomy.

This is not to say that the speaker doesn't matter. Once you peel the effect of the room, then you start hearing the low frequencies from the amp and speaker. If it bottoms out, gets distorted, these are things you need to fix but not before the room.

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From my perspective, you are absolutely correct. Time and again I have verified this myself in my system, where sitting close to the woofers the bass is really good, and when moving away it becomes less articulate.

Robh3606 said:

Hello Amir

I don't agree as I see it both the room and the speakers in equal measure. I don't care how good your room is if the speakers bass response is peaked or irregular it is going to be an issue. You also have to look at the low frequency extension and power handling . If the system can't do what you need it's all a moot point. You need to have a speaker up front that can do what you need placement comes second. Having a treated room doesn't fix everything there is no magic bullet.


Hello



I think you have that flipped You can easily measure 20Hz and not hear it, all depends on the SPL. At those low frequencies you need quite a high level signal to hear it. Go checkout the Fletcher Molson curves.

Rob

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I cannot really recall seeing any recent anechoic measurements on any decent speakers or subwoofers that had peaks in the bass. Yes, they have rolloff and some limit to their LF extension. So, how come in your room they have peaks? Hint: It is not the speaker.

And, acoustic treatments for bass peaks or dips are difficult because they must be huge to deal with bass wavelengths. Off the shelf treatments, even pricey ones, are largely ineffective in the deep bass below 100Hz. EQ has become a much more widespread choice, even by acousticians, for that reason.

I cannot really recall seeing any recent anechoic measurements on any decent speakers or subwoofers that had peaks in the bass. Yes, they have rolloff and some limit to their LF extension. So, how come in your room they have peaks? Hint: It is not the speaker.

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I am not talking about what's happening in my room just pointing out that the speaker has to be able to do what you want it to do. You should take a look at JA's measurements at Stereophile not all of those systems have a smooth bass response by any means. Fixing the room can't fix a flawed speaker design or one that can't go as low as you would like at the SPL's you need.

Rob

i agree that 'bass is the place'.

i 'think' I'm there on full frequency bass reproduction with balance, extension, and speed. but it's not been easy.

one huge advantage my approach has is that the speakers are truly full range, and completely integrated. no add-on crossovers or cobbled subwoofer integration into already full range speakers. the Evolution Acoustics MM7's twin tower (7 feet tall, 750 pound each tower) design has the main passive towers rolled off at the bottom so they seamlessly integrate with the active adjustable bass towers. the speakers are rated -3db @ 7hz and -6db @ 3hz. each bass tower has a pair of 1000 watt amps which each power -2- 15" subwoofers. the main towers each have -4- 11" ceramic woofers too. so that is a huge amount of driver surface which results in very low excursion.

the bass and main towers are laser aligned for time, and the 1st order crossover is phase aligned. the coherent waveform launch results in really articulate bass performance.

and I've finally solved my room bass problem. last summer i plugged up the last opening to the 'whole ceiling' bass trap and my one baggabo of a suckout at 30hz went away.

so I've got a large room, flat in the bass, with essentially unlimited headroom and extension.

i fought the room and it's nasties for 11 years and i finally conquered the bass. and everything now just flows and there is such an ease and authority to everything. i would never use the term perfect, but it's everything and more than i could ever expect to hear in the bass.

has my way over-the-top efforts including building a dedicated room been worth it? (it's a question)

what does this bass performance mean for the music in the big picture? there is simply a significantly greater overall degree of suspension of disbelief in the music now, and a level of involvement previously not present. like a bridge was crossed not previously even seen. less reproduced, more of something real.

the bass is the hard part. since every moment of our consciousness we experience a real world sense of space and authority in our lives. when a sound system can approach that more closely we relax and allow the musical message to pass through as something closer to real.

Mike Lavigne said:

so I've got a large room, flat in the bass, with essentially unlimited headroom and extension.

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In the world of acoustic science, your room is considered small. That aside, are you saying without any bass traps or EQ you have flat bass? And you credit the speakers with it?

amirm said:

In the world of acoustic science, your room is considered small.

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for home audio speakers it's considered a large room. 21' x 29' x 11'.

That aside, are you saying without any bass traps or EQ you have flat bass? And you credit the speakers with it?

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(1) no, I don't credit my speakers for a relatively flat room.....however the adjustability of my speakers helps to close the final gap to a smooth frequency response. and the fact there are 4 sets of pairs of powered adjustable subwoofers does offer a tune-ablity lacking in most integrated speaker systems. there is analog EQ (4 separate different adjustments) in the bass adjustments of each pair of subwoofers.

18 months ago my speaker designer spent 2 days in my room setting up my speakers. he discovered that I had a significant suck-out at 30hz but otherwise the room was very flat. he strongly suspected that my ceiling bass trap (open baffles into my ceiling soffits) was the source of the suck out. he had to make serious adjustments to the bass towers to get it to sound ok. back in 2010 I had removed other bass traps, and closed up much of the open baffles in the ceiling. but the last of these open baffles needed to be closed. I tried for a year to find a contractor to close these up. finally last August my son and I did the dirty deed.

(2) there are still 4 smaller (11' x 2' x 2') built in bass traps in the rear of the room.

(3) my room may, in fact, be very flat. but I don't claim that as I've not measured myself. I do know that after I closed up the ceiling trap that I had to radically adjust the bass tower settings to dramatically reduce the bass volume gain among other settings due to the elimination of the suck out. and I know that the bass performance has dramatically improved since this event, and every visitor since then has said the same thing.

All the bass nasties are totally deprendant on listening position .. so before you do any bass tuning , you need to nail down where you sitting..
Bass correction is done to suit that position.. and in fact , even if "fixed" , bass can be a lot worse than before at other positions in the room.

Yes.. bass is hard to get right , especially if like me , you love bass heavy material and play at some serious (lifelike) levels .. the louder you go , the more difficult

Flat is not what is wanted in the bass at listening position .. flat will sound very bass light.. ideally you want at least a 3db per octave slope upwards from 150hz down to the lowest bass your system can reproduce (house curve , room gain)
Bad bass just infects the whole audio spectrum and system..vital it's fixed to enjoy the rest and not have it masked via boom.