Just a Tease on Bass Driver Positioning

[T101]

You see, I experimented by putting a TL's mouth almost at ear level and cutting the bass driver low at about 250-300 hz...
- Result: A pleasant perception for lots of low bass... and very convincing too...

Another time I was sitting on on some pillows on the floor and the bass from my 12 inch Cerwin Vega's was much more adorable and true...

Another time I positioned my "18 GW H-frames on an elevated part of the floor of the room where they live and I sat down in the lower part of the room... again better and deeper bass...

Recently I was lying on the sofa and the sound of my Tannoy's (nothing special - Sensys DC-2) became much more dense and with much more impact... again deeper and stronger bass...

Three different rooms, four different sets of speakers and the same result...

Why we actually don't place the bass drivers at ear level, when it is much easier to position the mid and hi drivers elsewhere?

And yet another consideration - most homes and rooms limit the speaker dimensions in width, depth and rear wall spacing, but not in height...

And yet, yet another consideration... we all know how good some small/mid sized speakers perform when put on stands... What we get with a 50 cm (20in) high speaker on a stand?
- Yes! A bass driver around ear level...

I think of a high positioned bass driver + omni-directional upward facing FR driver + ST driver... - don't consider the topic to be about a project, just a thought or an instance about what can give us most possible design advantages...

And why not, when (and if) better bass is at hand as a no cost option... or, why putting the bass near the ground? I know the theory about ground reflections bass reinforcement, but it is disputable amongst specialists (at least my impression is that it is disputable) and can lead to multi-path-mess-y-type of interference or something...

Best regards and I look forward to read your thoughts!

[gfiandy]

Ground reflection bass reinforcement in not in dispute it is a measureable and predictable effect.

However this doesn't mean a system won't sound better with the bass driver further away from the floor. You may have too much bass or you may be sitting in a bass null in the room.

Normally the tweeter is placed at ear height as most speakers are designed to be flat on axis with the tweeter.

If you move the tweeter off axis then you will get less trebble and most likley you will percieve that there is more bass due to the reduced trebble level.

Regards,
Andrew

[Scott L]

I would have to agree it's worth trying, as I plan todoing this, BUT:

I also want my mid/ tweeter system to stay at ear level.

My plan is to place the point which is half way between the mid and tweeter at ear level, the low midrange below that, and the BASS the same height as mid/tweet, just to the OUTSIDE of the array.

[aptquark]

just put the speakers on a stand and turn your speakers sideways for heavens sake!

[Scott L]

Originally Posted by aptquark

just put the speakers on a stand and turn your speakers sideways for heavens sake!

LOL, your too funny !! I can't do that. Even if I could, I wouldn't do that !

My speakers are not in a box; well except for the bass driver, and I'll have to build a stand for it. Plus, I want my tweet/mid/ low mid all in a verticle line.


Have a nice day !

[aptquark]

Originally Posted by Scott L

LOL, your too funny !! I can't do that. Even if I could, I wouldn't do that !

My speakers are not in a box; well except for the bass driver, and I'll have to build a stand for it. Plus, I want my tweet/mid/ low mid all in a verticle line.


Have a nice day !

yea...just kidding. Though, when I did just that with my MTM's (they were too tall and getting in the way of my projector) I was still pleased with the outcome.

[Charles Darwin]

Never liked woofers close to the floor anyway hence my t/l subs are folded in a way that the t/l opens above the high mounted driver and just below the Tannoy DC I use.
I crossover at around 200Hz.

[T101]

Originally Posted by gfiandy

Ground reflection bass reinforcement in not in dispute it is a measureable and predictable effect.

However this doesn't mean a system won't sound better with the bass driver further away from the floor. You may have too much bass or you may be sitting in a bass null in the room.

Normally the tweeter is placed at ear height as most speakers are designed to be flat on axis with the tweeter.

If you move the tweeter off axis then you will get less trebble and most likley you will percieve that there is more bass due to the reduced trebble level.

Regards,
Andrew

What is on my mind is that altho it is a known fact, it is kinda discrimination for the lower frequencies to consider that longer wavelenghts propagate in 360 degree and despite room and height placement they will be anywhere in the room...

Yes it is a fact that longer waves are absorbed much less than the shorter ones and it is a fact that other thing with the ground reflection reinforcement...

We throw a woofer near the ground or in the corner and then in the best scenario we listen to some percents of direct bass sound and the rest is our room, furniture and etc...

And another consideration, we have tons of headroom and sensitivity with almost all midranges and tweeters, but we put them on ear level in order to perceive their 2nd and 3rd order distortion at it's best and to limit bass as much as possible.

Positioning the bass higher, if I am right, means to spend where you have the most - midrange and tweeter headroom. Most tweeters will burry your hearing for good if given the appropriate opportunity with high amplitude hf signal most midranges can be ubearably loud too... and I don't know of an example of single woofer that can be unbearably loud in home environment.
In numbers that would mean most woofers would have given up not later than 110 db and for most decent sized (6.5-8+) midranges and tweeters 110 db is some mediocre value achieved with no stress...

Despite all that we have to take care of the sounstage perception. - probably the most overlooked aspect together with phase differences due to different depth of drivers and different distance to the listener.
When we have one of the drivers covering most of the spectrum - almost every time the tweeter and sometimes the midrange, we rely on it to give us the positioning picture and neglect the fact that the other two drivers are on different opinion.

... What problems does the high positioned woofer introduce?

I see one possibility - woofers have deepest acoustic centre and tweeters the most forward... Arrangement from bottom to top driver - tw-mid-woofer can eventually produce equal distance from the acoustic centre to the ear of the listener if the ear is on axis with woofer center... and if the crossover frequencies are carefully chosen, then we would have a system that is naturally phase coherent at certain listening distance.

... and too many other question arrised just now, so I'll stop

The main topic is that listening to bass directly and on axis gives better details and better overall bass, with one subtopic - that reflected from anything bass is the same as any other reflected sound, namely: reflected - e.g. two waves traveling in different directions - e.g. messed...