Bad Bass

[christoffe]

http://www.stereophile.com/content/listening-124

[PeterSt]

An article to my heart !
Joachim, you finally did it.

Now I hope that XXHighEnd users hear something back of this. Especially those using a NOS1 ...

Peter

[Flecko]

To bass quality:
I am in the process of thinking about the way to make "wise" modifications of my room acoustics and in this contex thinking about bass traps.
My speakers have sealed enclosures and the bass is high pass filterd by a big capacitor, which is a not very common way to build a bass. I use additional bass deemphasis at 20hz to get some more "room"-information. Even at high levels the membrane movement can hardly be seen. Only a slight vibration is noticale, what I find remarkable for an 8" Bass. The sound of the bass is good but uneven distributet in the room. That is why I like to use bass traps to linearize the room response.

Does anybody has experiences with bass traps or an opinion on this?

[PeterSt]

Me ? Tweak as long as it takes to not need bass traps. But I think this is known (from me) by now. Maybe come over and listen how bass traps suddenly are needed all over the place, just by wrong "settings" (I put this a bit broad).
But if your room dimensions are wrong to begin with - relocate.

Sorry to be the first and sorry to sound rude, but it just is so.
Others are very welcome to respond differently of course. I may be the only one to have this opinion, but it is so easy to show it ...

Regards,
Peter

[Flecko]

The biggest problem of the room is, it is too small (17qm) but it has a good proportion to have the resonances distributet over some frequencies (and I can use it for audio only!) Your opinion ist most welcome peter. No offence taken
Lets say changing the room is no option.

With tweak you mean tweak in the electric domain?

[Robert]

I concur with Art and bass has got worse with the night club electronic generated dance music culture which has boiled over into recording studios, live concerts to the point that people believe this is real bass even with music instruments. We have all heard the booming car approaching.

I left BASS REFLEX speakers about 20 years ago by first blocking my ports much to the disgust of the speaker designer. When I got my REL subs it wasn't till I blocked these ports that I got the boom out of the bass.

I now own 2 subs that come sealed with a 12inch driver that barely moves. My Tannoy monitors are permanently blocked. Interesting they came from new with dense foam blocks to partially block them.

This from Barry Ober "The Sound Doctor" site http://www.soundoctor.com/whitepapers/subs.htm

A port is ALWAYS nothing more than a cheap way to attempt to get free bass out of an enclosure and /or driver that's too small. It's a holdover from the 1930's when because of driver inefficiencies (especially when compared to today's units) you had to do everything possible to increase the useable output over the desired range of frequencies.

Lets examine ported speakers. We'll start with the worst case, the port in the front. At mid bass frequencies, say 50-80 Hz, the LF driver moves IN the cabinet, the air in the cabinet is elastic, and the port air moves out of the cabinet. Because of the frequency at which the cone is moving, by the time the cone moves back out again, the port air is now moving out, so in front of the cabinet the two air pressure sources sum together and you get a fake bass "bump" or "boost".

He is not alone in stating this. I admit the room is the final frontier in achieving good bass. 

The other problem is people don't listen to a variety of concerts(classical, jazz, rock etc) in different venues to get a handle on sound in acoustic spaces. Industry(Professional and Hi-Fi) related people are some of the worst check Art's mention of Leo Fender for one, I was astonished at reading this.

Why are some off our recordings so bad?????

[PeterSt]

Same story here about "port closing";

My two (SVS) subs have 3 ports and came with two foam inserts (each) to tune them. With all open they do 12Hz, with one port closed 14 Hz, with two ports closed 16Hz and with all ports closed 18Hz. Used socks to close the third.

Woofers have a downfireing port which seemed the worse to me and go to 27Hz. Closed that port as well with no idea of the consequences. But since I have the subs anyway, it is fairly harmless to loose some bottom end on the woofers (and match the subs to that).

Loudspeaker designers must be funny sometimes, because somehow they think that the undoubtedly different phase coming from a port is harmless. Robert just said it. But while my woofers have a down fireing port, the subs have back firering ports but the driver faces the bottom plate.
For a longer while now I am thinking of putting the subs on the side so the driver faces the room. And yes, I will remove the bottom plate. Could be an ugly sight.

With some more experience, bass can be tuned "technically" by a. making it audible and b. let it not contribute to colour. This can only be done when there's first a natural instrument with known colour and which sounds good to begin with. And for example, before I had my own NOS1 this could not be done. This could not be done because the bass coloured to begin with, no matter how softly it was dialed in (I can tune the volume of my bass section separately). This, btw, is also how I can so easily show how bass traps are suddenly needed - just use a regular filter to the NOS1 (through XXHighEnd) and there you go (this mimics another more regular DAC). Or use Windows 8 in the (XXHE) state we know it.

Bass must be there but must actually be inaudible. This is hard to explain, but read that Article Joachim pointed out because in there some more words are spent on the subject, so no need to repeat that. But it is true. So, attenuate the bass in full and you will miss it. Dial it in until you start hearing it is changing the colour of what was there already without bass and you went too far. But this is also about balance, which (for me) comes down to this :

It is only maybe 4 months or so ago that I found my bass would not colour anymore, no matter how much of it I dialled in. I think I wrote about it in the forum, but I tried this because I have no single room anomaly (standing wave) in any corner anymore anwhere, so I thought it was time to try some more bass. Thus, this is all about the playback which has gone better (quite much with the later XXHE versions), and I thought I could seek new boundaries. Not needed, but I just tried it.
The same phenomenon which now has totally removed all standing waves, caused the bass not to colour anymore. Well, something like that. I think this not related to the interaction with the room, because I always tune this by sitting 50cm from the speaker, just because my amps are right under them;

I could dial in a nice fair amount of extra bass and thought it would work.
But it didn't at all;

There was still no standing wave to be seen anywhere, but the phase got strange. Gave an eerie feeling. This time any loudspeaker designer will say "but of course Peter, because what you've actually done is drawing the cross-over out of balance" (hard to explain without a drawing), but it was not that. As far as I could think of it was the sheer unbalance at least my brain could not cope with. Or not anymore because of what I'm used to. I always have the example of this sequence of happenings we may run into :

1. Live concert - nice cymbals.
2. Nice stereo - cymbals can be better. Ride cymbals is OK.
3. Improved stereo, cymbals have attack which is in balance with sustain and decay.
4. Go back to situation #2. Brain can't cope because attack of cymbals is missing. OUCH.

This really is so. This, while #2 followed #1 and strangely enough we have no problem with that at all.
I think in same fashion we can get used to a good balance, and when this balance is destroyed or even gets less only, it incurs for brain damage. But at the same time you can tune your bass with it. And not to forget, this is within fairly small limits because you can't just put up or down the volume of bass opposed to mid(/high) without changing the crossover.


What people (logically) refuse to realize is how common DAC filtering and so-so playback software makes you acquire bass traps and new speakers. You can't because you are behind the facts and the damage has been done and can not be corrected. It can be masked though, but all you will do is let go the goodies with it. Like I said (merely implied) it in another topic recently : A wooden floor is actually so good. But who dares ? today I would for 100% sure. But if I, today with carpetted floor, would hook up my same NOS1 to a Mac and praised Audirvana+ and use a proposed filter ... you would not now what have happened. You'd be astouned that just another player - but merely that normal filter is causing all this all over sh*t and you'd be sure to move house when you didn't hear the reference. You would tell me that my speakers are in the wrong position, that I need thicker curtains, that my room is too large, that actually my GainClones are just GainClones and *all* what you can think of. And you are so wrong, because it is just and only the source doing this to you.

But how to believe this.

Peter