Eminent Technology ET-2 Tonearm Owners

Dear @dlcockrum :  The main and critical subject to add a pair of  self powered subwoofers integrated in true stereo fashion ( this is that the main speakers will function as " satelite " ones. ) is to lower significatively the INTERMODULATION DISTORTION and THD too.

In those all times from where comes your speakers and mine almost no single designer ( as JT. ) was thinking on designs with integrated subs, maybe only ATC was marketing active speakers as a ATC philosophy and not necessary with suibs.

Today the best speakers comes with integrated powered subs ( Vandersteen 7 is one of them but many more out there. ) for that critical subject.

In your speakers those two small woofers ( that can even one 12". ) are handling frequencies from  over 100 hz ( first order filter. ) don 20 hz . Are so small that can't really " drive "  in the right way bass range from 40 hz and down and this means high distortions but at the same time those drivers are trying to " drive " 25 hz-30hz-40 hz-80 hz- etc and the high excursion of the drivers because the low frecuencies affect e increment a lot the IMD in the whole frequency range of those drivers.

"""   it concerns me regarding tampering with Jim Thiel’s ingenius 1st-order crossover... """

No, you can't do that but only an outstanding overall improvement that you don't have today, you just can't imagine till you do it and listen it. The whole subject is not to reinforce the low bass but put at minimum that elusive IMD/THD in the very hard to handle low bass range, benfits as better quality bass performance is only a side benefit.

Problem in your system are the RELs that has not ( no sense to me. ) a high pass control. Rels are very good as system bass reinforcement but not to really help to have a better quality overall performance.

When I posted the thread in the link I send to you almost no one believe on what I posted there. This already changed today and not only music lovers as all of us but speaker manufacturers that now knows not only about that IMD/THD but that exist no passive drivers that can handle with aplomb the low bass range and not only does not exist but that are not mated with a dedicated amplifier that match the drivers needs in exactly and precise way.

Even speakers as the big Wilson can has a real benefit ( incredible. ) if their woofers been active instead passive.

Regards and enjoy the music,
R.

@dlcockrum : The external crossover we need to do that could be only for the subs but not use that croosver for the speakers main amplifier where a technician can easily to make the first order high pass down at the amplifier inputs through a cap and resistor combination calculated for a 80 hz high pass filter.

As me you can use a top teflon cap and the best Vishay nude resistor, both extremely transparent. In this way the signal inside your speakers will stay almost untouched.

Why 80 hz or even a little higher as 100 hz instead 50 hz?, because that first order Thiel croosover where the single 8" woofer that handles a frequency range from 50 hz to 400 hz ( I think. ? ) right now is taken frequencies way lower than 50 hz and with higher IMD/THD that if you liberate it.
In the other side your amp will works with lower distress that's mean lower distortions too.

Advantages are many only  we just do it. Believe you don't now today the real capacities of your very nice audio system and you will be " surprised " for say the least when you listen it in that configuration.

Regards and enkoy the music,
R.

Hi Raul,

I trust that you and many others have heard the benefit of eliminating the low frequency signal to the main speakers. The YG Acoustics speakers that my friend has have separate powered woofer sections and also he uses JL Audio Gotham subs. Again, he relies on digital room equalization to make all of this complexity work together and well, according to his reports.

True, the RELs have no high-pass output as they were designed to do something different and that they do well IMO. What sub that you own or have heard has high-enough quality internal crossovers to do this well without introducing other compromises to the sound? I would prefer to handle the high pass/low pass filter this way vs modding the Thiels (which would also not relieve the low-frequency-reproduction challenge for my amplifiers). But then there is the additional long runs of low-level cabling needed to use a sub crossover solution...

Yesterday, I experimented with using my HT processor to alter the low-frequency hand-off between the Thiels and the RELs. Some promising results in the bass, but there was pervasive degradation to every other sound criteria as one would expect from this "mid fi" approach.

Since I cannot afford the latest and (maybe) better-than-what-I-have-now plug-and-play components, I find satisfaction in experimenting with carefully-chosen tweaks and acknowledged "better-than-they-could-possibly-be-for-the-price" components from the past.

Right now I am enjoying power supply upgrades to the SR cables/cords’ active shielding (great results for small $$) and, soon, SR Black fuses (due to arrive Friday). I just picked up a Sony 5400ES SACD/CD player that I may have ModWrighted with improved clock, separate dedicated PS, and tubed output. Claimed to be a "Giant Killer".

Begging the pardon of my ET Two friends (particularly Chris) for this shamefully non-related indulgence.

Thanks as always, Raul, for your contributions and advice,
Dave

Dear @dlcockrum : I know that the Krell amp is a powerful item but even that and even that works almost all tghe time looking 2 ohms impedance from the Thiels this means more distress and higher distortion that if the amp works at a little higher impedance. That distress could means too more " fatigue " for the amp power suply and output transistors. So, it's not only to think that the amp can make " easy " that work, there are side issues to look for and care.

My suggestion of that tefloncap/nude Vishay resistor at the amp inputs still is a good alternative and inside that first order Thiel filter design. As a fact is the kind of filter that makes less harm to the sound signal.

No one sub I know works in the high pass with first order filter design.

When we are talking of subwoofers for an stereo system dedicated to listen music there is one parameter of critical importance and this is the THD of the subwoofer and in this regards no one is even near the 0.5% of thwe sealed Velodynes thank's that its design monitoring the woofer excursions over 16K times per second to mantain that so lower THD. Nothing can beat it on quality performance. Otehr can go lower or sound more powerful but with loweer quality performance and its croosver design is a decent one.

I own the out of production HGS-15 but you can find out ( second hand ) the DD-15 ( newer model. ) that in my opinion performs better than the DD-18 or in my case HGS-18.

In the other side you can buy a top croosover to hadle the signal from your preamp to the Krell and to the RELs.

Regards and enjoy the music,
R.

The subwoofer phenomena is an interesting one, but logical IMO, as far as progression goes in this Audio business. There are not too many people that have dedicated rooms, that can place full range speakers on the room loading points. So manufacturers followed with subwoofer audiophile lines to meet this demand. It’s a good business model imo.

As we know with subwoofers you can place them in the general area of where you want them, then set when they are active, and amount of db level with the phase control you need. Still the person with the dedicated room will be able to go further down the rabbit hole if these bass modules can be placed on the room loading points to begin with.

The real issues I find with bass does not get much discussion on forums and it deals with the way the music has been engineered to begin with. Different genres of music and even different recordings within the same genre use different compression levels, engineering techniques. Different albums need different bass settings.

Now most people I know with subwoofers have a dial on the actual box/es that they use to set phase and db level, etc... In order to tailor the sound for different music the person needs to get up go to the sub/s and change them. This doesn’t work for me.

In my room B, I am using two Dynaudio BM12s subs that have a credit card sized remote that can be preset for A - B - C - D . Each letter represents different settings. When the music has been engineered with too much bass or too little, the levels are easily adjusted from the listening chair. Unless you can train your dog to change the levels while you listen; this works very well, for me anyway.

Raul - have you ever heard a system that had four bass modules in the room? I am not referring to four on the ground. But Two on the ground. Two up near the ceiling. Four in total facing the listener for two channel music.