Phono Stage upgrade to complement Dohmann Helix One Mk 2

Dear @mijostyn  : In this regards and with all respect I really don't care of your opinion because I'm not talking of your " holly grail ". Live with and let live.

 

R.

Dear @drbond  :  I can see that you are not taking bass quality level sound that's the first and critical target when we are speaking of true high end.

Integration of subs is not only to lower IMD but the bass THD response level because its harmonics are the ones that puts " dirty " and makes that the mid/high frequencies range get dirty too and this fact has a name: degradation sound reproduction.

Talking of quality lvel performance I can't know how your sub's seller can even the quality of the Krell/Gryphon amps and how the THD of each sub stays inside 1% at full power down to 20hz.

In the other side I xcould think that your seller/manufacturer will gives you a configuration of 4 sub's that helps to even the room bass response especially to use in HT systems where you need several seat positions with that evenly bass.

In the other side if your main system is for listen stereo MUSIC then normally you have only one seat position where the mid/high frequency ranges performs at its best and the Harman Int. research shows that for one seat position 2 subs performs really good.

I can't link here the 30 pages of that modeling deep research and here only some highligths:

 

 

""" With 5000 subwoofers, modal variation is virtually eliminated. The frequency response at all 16 seats is nearly identical. ASIDE This curve is a combination of 2 influences: The power response of the modeled subwoofers (the simulations included measured Entre 12” subwoofer power responses). The effect of the real-world subwoofer response can be seen above 8 Hz. ""

 

""" The next four figures show results of optimization of 1 to 4 subwoofers in the test room. Locations of subwoofers were constrained to be along the walls, at intervals of 2 feet. Optimization is based on Std only, i.e. the configuration with the lowest std is considered optimum.  ...Obviously, wall midpoint locations result in optimum room response, based on the std anyway. Not surprisingly, symmetrical configurations seem to work better than non�symmetrical ones. Four subwoofers results in the most symmetrical configuration and the best results, but with significantly less (normalized) low frequency output than two subs """

 

"" Two and four subwoofers at the wall midpoints are still the best configurations overall. Four subwoofers in the corners does not seem as advantageous as when the grid was centered. There is still little or no advantage to using a large number of subwoofers. LF factor still goes down for higher numbers of subwoofers.  ""

 

""" One subwoofer at each wall midpoint is the best in terms of Std, Max-ave and Max-min but does not support low frequencies particularly well. Two subwoofers, at opposing wall midpoints, performs very nearly as well as four at the midpoints and gives a much better LF factor. One subwoofer in each corner also has good low frequency support, but does not perform quite as well as one subwoofer at each wall midpoint, in terms of Std, Max-ave and Max-min. If cost and aesthetics are considered, subwoofers at 2 wall midpoints is preferred. ""

 

 

The fact that 4 sub's could even the bass response it does not really matters if you have one seat position where 2 sub's can doit if the sub's have the whole quality levels.

I don't know if you noted on different links in my last post that all those subwoofer ( as the Magico. ) use metal frame for its box. The 1% THD does not comes  just at random no inclusive Gryphon said something That I posted here: " his dedicated class AB amps were designed to fulfill the woofers needs and re-read what Dan ?dagostino said in his Krell sub manual and what Wilson posted too and Evolution Acoustics where its common denominator/main target is QUALITY and a side advantage of that quality is to have deeeper bass response.

 

Anyway is up to you and of course is your money and only you can decide how spend it or invest it.

 

R.

@rauliruegas , now you've hurt my feelings. No desert for you tonight:-) There are a few strange comments your references make. Nodal behavior is a function of the room. Certainly it can be modified by placement. This fellow asserts that more drivers result in a lower LF factor (Low Frequency). I can only guess what he means by this.n Maybe @lewm knows.  Larger and more numerous drivers decrease excursion distances resulting in less distortion. He want to position subs at the midpoints of walls. If you are using your subwoofer array to lower distortion in the main speakers the higher crossover points have more benefit particularly with ESLs. Crossing at 100 Hz requires a stereo subwoofer array to avoid locating the subwoofers. There are also differences in requirements for the type of main speaker, line or point source. If you put a point source subwoofer array under a line source the subwoofers will become lost not having the same power projection. Its easy to cut volume but harder to increase it. Given large high quality drivers the quality of the subwoofer is mainly determined by the enclosure, large enclosures being significantly more problematic. Controlling resonance in a large panel is much harder than controlling resonance in a small panel. Given proper digital signal processing it is very possible to make a 1.5 cubic inch enclosure with two 12" drivers. Given enough power you can make them do anything you want and you do not need ports to get lower. We have the automotive crew to thank for modern driver designs, light cones, large voice coils and magnets, kapton formers, adequately vented, with shorting rings to lower distortion and finally long throw suspensions and kevlar spiders. You can get the finest subwoofer drivers for $250.00.

The wife wants me to make dinner. 

We have the "automotive crew" to thank for ear-damaging incoherent bass thumps, not music.

drbond, I love classical music and especially I love Bach, because he would have been a great jazz composer.  I just have the Clint Eastwood approach to deepest bass: "A man's got to know his limitations."  Which in this case means I would not make the sacrifices or put up the cash needed to generate 16Hz in my listening room.  There is probably only one actual organ (let alone an audio system) in the DC area that can reproduce that note, at the National Cathedral, about 4-5 miles from our house. But I admire your determination.