Eminent Technology ET-2 Tonearm Owners

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.

Chris,

Another intelligent and insightful post. The path in the carpet to my subs is worn from countless trips to and from for adjustment or simply turning them on or off depending on the media. From recording to recording I find that the subs either augment or detract from my musical enjoyment and your posit on the variability of mastering decisions, which cannot be altered after the fact, is the best theory that I have read or heard to date. 

Additionally, having a dedicated room, I have the freedom to place the subs wherever I like, and have spent many hours trying to tune placement to best effect, yet periodically wonder if the sweet spot is yet to be discovered.

Is it worth it? Depends on one's level of OCD affliction, the subject room/system and, as you describe, the media itself.

Best,
Dave

Dear @ct0517 : I don't have a dedicated room. I took around one year to my subs position and levels be " just perfect ".

What means " just perfect "?, first that you can't identify where the subs sounds comes, everything ( overall system frequency range. ) comes from in between speakers and extended beyond but sounds emmanate from in between. Second you never need to change the SPL of the subs, simple stay with the final overall set up. If you need to change the subs set up with different LPs then your final set up is not yet final and needs more " work " to achieve that goal.

In my system its position is in front of the main speakers ( satellite ones. ) looking each to other sub not looking to the seat position but at right/left side: front to front. Are not directly seated in the floor/ground but around 40 cms. up and with 30 kg dead weigth in its top plate.

Yes I listened four subs in my system many years ago when I owned too: two Audio-Pro ( Sweden ones. ). As a fact the ideal way to add subs in any audio system is using four subs to eliminate any single standing room waves.

Remember subs main/primary premise is not to have deeper bass or " boom boom " but better quality overall system performance with lower distortions!.

Regards and enjoy the music,
R.

Raul - from personal experience in my room when you have multiple bass drivers, one positioned high near the ceiling and one low - pointed at the listener. The effect of the output from the woofers is that the bass waves cancel each other out. The sound is much smoother, bass notes stop and start quicker. There are no standing waves.

It costs a lot to do this type of speaker design, they are tall and substantial for the top woofer to reach high and for the cabinetry to be able to hold the weight. They are very imposing in the room. If a manufacturer makes this type of speaker they are usually their flagship line. Not many made like this anymore
.

Remember subs main/primary premise is not to have deeper bass or " boom boom " but better quality overall system performance with lower distortions!.

Well the job of the subwoofer is to reproduce low frequencies. In most cases, the bottom two octaves, from 20Hz to ....the higher frequency varies for each persons room. Now I believe in all designs (someone correct me if I am wrong in this assumption) the least distortion for any design, will be when the sub is working the least - IMO.

When it is working is triggered by when it has been set to kick on (the frequency), and how loud it has been set to play at when it kicks on. This second part is IMO key (how loud it has been set for), especially if someone is using One subwoofer. let me explain.
   
If anyone owns one subwoofer and you want to learn how clean it can play - lowest distortion try this experiment with one subwoofer.

Place it a few feet to the left or the right of your listening position. If it used to be on the other side of the room, change the dial on the phase control 180 degrees to start.
Start playing your music; if the sub used to be close to your main speakers on the other side of the room, you will need to turn the db level of the sub down at least 60 - 70%.
Set it up for your music. You will not be able to tell that it is next to you. In fact you can play a game with your audio friends. 
Camouflage the sub with a nice cover. Let your friends sit in your chair, start playing music and ask your friends to tell you where the sub is located. They will point to a far corner somewhere. They will be surprised when you tell them it is 3 feet beside them. try it ...

**********
True Story

Two weeks ago my 22 year old son comes over with his truck.  As it pulls into the driveway, I was able to can hear the vehicle thumping with bass from before he entered the driveway. Fed up I told him we are going to try something. For the record this vehicle comes with decent stock stereo (for car stereo ) I think sourced from Alpine and has a nice big cabin (Room). He has added a JL Audio amp/controls under the passenger seat, and two JL Audio Drivers under the back seat in a long custom box. The first thing I noticed was that his stock sub was still on. Why? It was redundant and competing with the JL Audios. We went to the dash and turned off the vehicles stock sub. I then reached down under the passenger seat where the controls were - I turned the frequency the sub kicked in, a little lower and turned the db level from 6 ! ....to 3. I asked him to play some music. He could not believe it. I can now hear the bass he commented. I felt good but it was short lived. Couple days ago he asked if I could show him how to turn it back the way it was, just so he could learn how to do it. I think its one of these things when guys get together that your vehicle needs to be thumping. :^(