Do you think you need a subwoofer?

@mijostyn  : Sorry but your post has no meaning for me or I made a poor explanation in my other post.

R.

Dear friends : In this subs issues we have to follow the Physics rules. Here a room mode calculator:

Room Mode Calculator_0.xls (live.com)

and here why at one seat position 2 subwoofers are good enough to listen MUSIC, we don't need 4 but we can use those 3-4 additional in HT but not need it for MUSIC only:

Microsoft Word - whitepaper10.doc (harman.com)

R.

" Two subwoofers, at opposing wall midpoints, performs very nearly as well as four at the midpoints and gives a much better LF factor. "

That’s the Harman conclusion. Now, if we are using our room/system mainly to listen MUSIC where is the bass range we need be reproduced by subwoofers?

Mainly from around 50hz-60hz and down at least to 16hz but 80%-90% of our daily reproduced MUSIC bass range belongs from 60hz/70hz to 30hz and for me this is the main ( other than put at minimum the Doppler effect/IMD ) desired dedicated drivers to bass reproduction and here the phase subs control is way critical. Yes some kind of instruments MUSIC reproduction needs that the subs can works fine from 25hz to 16hz, fine means with absolute aplomb. My Velodyne has usuable 10hz frequency but not so important.

In my latest phase experienced tests I been totally sure about because the overall reproduced sound over all the system frequency range was and is improved in its quality levels as ever before the phase subs change and was only this parameter the one I touched in the subs : same volume, same crossover point, same everything including the subs positions, nothing then but the phase.

Other critical and way important issue when we are integrating subwoofers in our MUSIC system is to have a " rigth " blend " between the sub’s crossover point and the main woofers crossover point.

It has to works exactly as speakers designers do it with his speakers where they choose the rigth crossover frequency of the different filters ( HP, LP, BP ) using normally between first and third order for those filters according each frequency range driver to BLEND . No one use 6 or eigth order filters because the issue is to BLEND and not separates the frequency ranges. Then, this BLEND along the Phase are crucial.

R.

Well, Velodyne makes the blend at crossover frequency with a second order filter shape and latter on pass through fourt order and finished at 48db per octave in my HGS and the Velodyne HP is a first order filter (6db. ).

The name of the game is that blend at 12db per octave along the 6db per octave that in my case is not made by the Velodyne but at the input of my Levinson monoblocks..

R.

Dear friends: from my last sub changes I confirm that that doppler developed characterisc in woofer main speakers must be should be at absolute minimum.

The issue is that the bass range is all about MUSIC room/system quality level reproduction and the bass rage must be perfectly blended inside the bass range. This is high mid-bass, mid-bass, low mid-bass, low bass and deep bass.

That blend must permit that we be aware of eacg bass frequency range with out a bass frequency range " leader " or " leaders " and all those is the true challenge we have with the subwoofer room/system integration.

That bass frequency ranges blend will gives me the best MUSIC rythm ever and the perception of dimensional MUSIC presentation where each track performs in its each territory that’s our room seat position.

With out all those we can’t really have true MUSIC enjoyment and only " something " that we like it..

Not an easy task that bass range frecuencies blend because it’s as complex as a speaker design where the designer needs not only to choose the rigth drivers but the rigth crossover frequency for each driver and the crossover filter shape that permits a seamless blend that’s what makes the differences between a good speaker and a very good or excelent speakers.

Here mijostyn  looks as he knows about and maybe could share his point of views.

R.