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Discussion Starter #1 (Edited)
Owners

Darkmatter - Single KK DXD808
Recruit - Single KK DXD808
Audiofan1 - Single KK DXD12012
Kenny Powers - Single KK DXD12012
Asere - Single KK DXD12012
13T - Quattro KK DXD12012


Compilation of Kens Responses

About Sub Placement and the Benefits of DUO Configurations
Thanks for the kind words, they are always appreciated.

Further to our discussion, I just posted the following on another Home Theater Shack thread that perhaps is better suited posted here:

The side of the DXD cabinet with the side driver is designed to be optimally placed 2-4" from the wall, preferably in a good solid corner of the room. For most rooms, I usually recommend first locating the DXD in the closest solid corner to your primary listening position. So, if the closest solid corner (no nearby openings like an open door) is in the back of the room, try it there first.

Every room is different and needs some experimentation with subwoofer placement. But, after measuring literally hundreds of studios and rooms with very sophisticated TIME DOMAIN measurement equipment with the world's best laboratory measurement microphones, and my own proprietary analysis technique (which measures and computes very much like our ear/brain mechanism interprets the spectrum of sound energy heard over time including and especially transients), the closest solid corner has the best chance of giving you the best and most accurate "out-of-the-box" results, in my humble opinion and experience.

The DXD's are specifically designed for corner placement which normally will give you the least room mode problems, especially if you are using the stacked DUO configuration which is technically a whole new subwoofer for a host of technical reasons.

Here is what I just wrote in another Home Theater Shack thread about this:

"Yes, a DUO will be AUDIOPHILE BASS NIRVANA for you, I guarantee it! As good as single DXD-808's and DXD-12012's are, it is a whole new experience in the DUO configuration because they are technically a whole new type of subwoofer from the single cabinets, I designed it that way.

Once you stack at least one pair, you have my full BALANCED 3D HIGH VELOCITY PUSH-PULL-PULSAR DEEP BASS PRESSURE WAVEFRONT LINE ARRAY NEARFIELD technology operating in all its glory!!!"

The DXD's can be placed anywhere in a room, but optimum performance in most rooms will be achieved in a corner placement, again, I designed it that way for all the good reasons.

Also worth noting, the DXD's performance secret (please don't tell my competition this secret) is they are very specifically and deliberately and scientifically designed to give optimum bass performance in a real room or studio with real walls, not in a parking lot outdoors where a lot of review measurements are made for subwoofer comparisons. The same holds true for close-up type measurements where only part of a DXD's output is actually measured.

The DXD's put out a sound pressure wave in multiple directions and cannot be properly measured outdoors or close-up, this is a big mistake some reviewers are making. It is somewhat analogous to trying to measure the horsepower on the ground of an ALL WHEEL DRIVE vehicle with a dynamometer, but only measuring the horsepower at one wheel.

I actually get a big kick at the outdoor and close-up review measurements which show the DXD's appearing to have unusual output levels and response, and then when a reviewer listens and measures in a room they usually comment they cannot believe how much pants flappy energy and impact is heard and felt in their real listening room with real walls and how low the DXD's measure in the room. Remember (another top secret not to tell my competitors), I don't use high pass protection filters in my subs (they ruin the bass impact) so they will go all the way down in a real room with real walls.

My mentor, Dr. Lester M. Field, used to say "the device is the perfect analog of itself!"

GOOD SOUND AND GOOD BASS TO YOU...ALWAYS...KEN

The Difference between the XLR/RCA inputs
I have seen several thread discussions and several thread speculations about the level sensitivity difference between a DXD sub's RCA input versus the XLR input when using an unbalanced RCA to XLR signal adapter to the XLR input (instead of using a normal professional balanced XLR input signal) and why sometimes the XLR input either sounds better or has less hum in some situations.

The DXD's RCA and XLR inputs are calibrated to a particular professional standard (can I say THX?). The RCA's input REFERENCE LEVEL to achieve a certain dB SPL (known as the REFERENCE LEVEL) is 100mv (.1 volt). The RCA has a ground connection and a hot connection, and the .1 volts is measured between the hot and ground connection.

To achieve the same dB SPL output level from the XLR input, the XLR needs to see 200mv (.2 volts) on its input (twice the voltage). The XLR has a ground, a hot terminal (pin 2) and a negative terminal (pin 3). So, pin 2 sees +.1 volts and pin 3 sees a -.1 volts. The +.1 volt plus the -.1 volt gives a voltage potential of .2 volts at the balanced input of the XLR, which is 6dB (twice the voltage gives +6dB) more signal level than the .1 volts seen on the RCA input. This means that technically the XLR input needs 6dB more input signal drive level (twice the voltage) to get the same dB SPL output from the sub.

So, if you use the XLR inputs unbalanced with an RCA to XLR adapter, you are only feeding a signal to pin-2 of .1 volts as there is no voltage on pin-3, so the XLR input with .1 volts on pin-2 will have -6dB SPL output level below the same .1 volts on the unbalanced RCA input.

So again, technically, on the DXD, if you use the same unbalanced signal from your surround processor to feed either the DXD's RCA input (only one RCA input) or the XLR input using an unbalanced RCA to XLR adapter, you will have a signal level sensitivity of -6dB SPL lower on the XLR inputs, again when using an unbalanced signal into the balanced XLR input.

If you happen to be using a Y-connector to feed both RCA input's, and then try the single XLR input with an RCA to XLR adapter, you will see a +12dB SPL difference between the two RCA inputs versus a single XLR input. This is because feeding both RCA inputs (.1mv LEFT input + .1mv RIGHT input) with a Y connector feeds twice the voltage (+6dB) to the DXD compared to feeding a single RCA input.

As to the reduced hum using the DXD's XLR input there can be two reasons. One, using an RCA to XLR unbalanced adapter to feed the DXD, the DXD will require 6dB more signal drive level to get the same output, so if you increase the subwoofer output drive signal of your processor by 6dB, you will reduce any hum by 6dB compared to the RCA input. Secondly, as mentioned on the description page for the DXD's it states "The balanced XLR input uses a High Performance Professional Instrumentation type balanced circuit design, which can even help eliminate hum in some unbalanced situations were a ground loop exists..."

Hope this answers the question...KEN

A question about the XLR Pass through if using an unbalanced XLR connection from the AVR

The XLR PASS-THRU will not change anything.

As it is marked on the back panel of the DXD, the XLR OUT is a passive "DIRECT PASS-THRU (UNBUFFERED)" so whatever type signal (balanced or unbalanced) is at the XLR IN appears identically on the XLR OUT. It is the same as if you were using an XLR Y-adapter, which is a totally passive PASS-THRU.

As to the TRIM issue, I would need more specifics about your AVR and what levels you are actually measuring. You could also buy my upcoming STUDIO BASS OPTIMIZATION & CALIBRATION BOX and not worry about it...KEN
A question on max output of 808 and 12012 subs

First let me say that you don't have to worry about damaging a DXD-808 or DXD-12012, they can take just about anything you can throw at them. They are built for continuous, year in and year out, heavy duty studio use where you cannot imagine what is both deliberately and unintentionally sent to the subwoofer during major blockbuster film sound design sessions, I assure you it is far beyond your wildest sonic imagination. Also realize that the DXD's can take all of this even though they do not have the usual high-pass protection filter (which ruins the transients and impact) used by most subwoofer manufacturers (out of fear of damage to their amp and/or driver with high level subsonic signals).

The only caveat is if you have line voltage in excess of 240 volts and do heavy duty subsonic testing with test tones or accidently or deliberately do a high level auto calibration sweep (usually below 10Hz), there is a remote possibility you might fatigue the AC power fuse which is there to protect the amp from abuse or from large power surges from lightning storms or extreme power line surges, and the fatigued fuse might blow when the DXD is turned on due to an excess power surge on turn-on, again usually only if your line voltage is in excess of 240 volts (I have only seen this issue with a handful of owners in the UK and Singapore where they have all measured their line voltage in excess of 240 volts). A new line fuse takes care of it.
 

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A single one here, hoping to make it a Duo at some point in the future and that will be my bass nirvana for me :)



Demo List

DVD-Audio & SACD's

Herbie Hancock - Gershwins World SACD 5.1
The Band - The Last Waltz DVD-Audio 5.1
Train my Private Nation - SACD 5.1
Steely Dan - Two Against Nature DVD-Audio 5.1
Steely Dan - Gaucho DVD-Audio 5.1
Jean Michelle Jarre Areo - DVD-Audio 5.1
Organ Spectular - DVD-Audio 5.1
Yes - Close to the Edge SACD 5.1
Spyro Gyra - Wrapped in a Dream SACD 5.1
Spyro Gyra - Original Cinema SACD 5.1
Steve Wilson - Grace for Drowning DVD-Audio 5.1
Yello - Touch DVD-Audio 5.1
Yello - Stella DVD-Audio 5.1
Horizon & Friends Late Night Chill out Lounge - SACD 5.1
Randy Newman Little Criminals - DVD-Audio 5.1

Blu Ray Demo

Dolby - The sound of High Definition II BD - Dolby True HD
Dolby - The sound of High Definition 3 BD - Dolby True HD
The Police - Live in Concert - the infamous disc that you all must have by now and one that I have been using when I had the MX5100SF and it sounds even better with the new DXD subs.

This is just a few of my music DVD-Audio's and SACD's which are a few of my favourite since getting the DXD808 but don't forget you can also listen to them in 2 channel as well
 

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A single one here, hoping to make it a Duo at some point in the future and that will be my bass nirvana for me :)


Yes, a DUO will be AUDIOPHILE BASS NIRVANA for you, I guarantee it! As good as single DXD-808's and DXD-12012's are, it is a whole new experience in the DUO configuration because they are technically a whole new type of subwoofer from the single cabinets, I designed it that way.

Once you stack at least one pair, you have my full BALANCED 3D HIGH VELOCITY PUSH-PULL-PULSAR DEEP BASS PRESSURE WAVEFRONT LINE ARRAY NEARFIELD technology operating in all its glory!!!

In the meantime,

GOOD SOUND AND GOOD BASS TO YOU...ALWAYS!!!

KEN
 

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Yes, a DUO will be AUDIOPHILE BASS NIRVANA for you, I guarantee it! As good as single DXD-808's and DXD-12012's are, it is a whole new experience in the DUO configuration because they are technically a whole new type of subwoofer from the single cabinets, I designed it that way.

Once you stack at least one pair, you have my full BALANCED 3D HIGH VELOCITY PUSH-PULL-PULSAR DEEP BASS PRESSURE WAVEFRONT LINE ARRAY NEARFIELD technology operating in all its glory!!!

In the meantime,

GOOD SOUND AND GOOD BASS TO YOU...ALWAYS!!!

KEN
Good to hear from you Ken, I think you just twisted my arm, Lol :D

Thanks for giving us such great kit to play with :T
 

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Good to hear from you Ken, I think you just twisted my arm, Lol :D

Thanks for giving us such great kit to play with :T
Thanks for the kind words, they are always appreciated.

Further to our discussion, I just posted the following on another Home Theater Shack thread that perhaps is better suited posted here:

The side of the DXD cabinet with the side driver is designed to be optimally placed 2-4" from the wall, preferably in a good solid corner of the room. For most rooms, I usually recommend first locating the DXD in the closest solid corner to your primary listening position. So, if the closest solid corner (no nearby openings like an open door) is in the back of the room, try it there first.

Every room is different and needs some experimentation with subwoofer placement. But, after measuring literally hundreds of studios and rooms with very sophisticated TIME DOMAIN measurement equipment with the world's best laboratory measurement microphones, and my own proprietary analysis technique (which measures and computes very much like our ear/brain mechanism interprets the spectrum of sound energy heard over time including and especially transients), the closest solid corner has the best chance of giving you the best and most accurate "out-of-the-box" results, in my humble opinion and experience.

The DXD's are specifically designed for corner placement which normally will give you the least room mode problems, especially if you are using the stacked DUO configuration which is technically a whole new subwoofer for a host of technical reasons.

Here is what I just wrote in another Home Theater Shack thread about this:

"Yes, a DUO will be AUDIOPHILE BASS NIRVANA for you, I guarantee it! As good as single DXD-808's and DXD-12012's are, it is a whole new experience in the DUO configuration because they are technically a whole new type of subwoofer from the single cabinets, I designed it that way.

Once you stack at least one pair, you have my full BALANCED 3D HIGH VELOCITY PUSH-PULL-PULSAR DEEP BASS PRESSURE WAVEFRONT LINE ARRAY NEARFIELD technology operating in all its glory!!!"

The DXD's can be placed anywhere in a room, but optimum performance in most rooms will be achieved in a corner placement, again, I designed it that way for all the good reasons.

Also worth noting, the DXD's performance secret (please don't tell my competition this secret) is they are very specifically and deliberately and scientifically designed to give optimum bass performance in a real room or studio with real walls, not in a parking lot outdoors where a lot of review measurements are made for subwoofer comparisons. The same holds true for close-up type measurements where only part of a DXD's output is actually measured.

The DXD's put out a sound pressure wave in multiple directions and cannot be properly measured outdoors or close-up, this is a big mistake some reviewers are making. It is somewhat analogous to trying to measure the horsepower on the ground of an ALL WHEEL DRIVE vehicle with a dynamometer, but only measuring the horsepower at one wheel.

I actually get a big kick at the outdoor and close-up review measurements which show the DXD's appearing to have unusual output levels and response, and then when a reviewer listens and measures in a room they usually comment they cannot believe how much pants flappy energy and impact is heard and felt in their real listening room with real walls and how low the DXD's measure in the room. Remember (another top secret not to tell my competitors), I don't use high pass protection filters in my subs (they ruin the bass impact) so they will go all the way down in a real room with real walls.

My mentor, Dr. Lester M. Field, used to say "the device is the perfect analog of itself!"

GOOD SOUND AND GOOD BASS TO YOU...ALWAYS...KEN
 

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I just love the thought of a DUO combination now, I think it will be my last stop, that is until you release some more speakers that is :)
 

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Discussion Starter #7 (Edited)
I do really like the prospect of a Duo as well, the principle of it seems like very logical engineering! I am just not sure if it would be better to just bite the bullet of going to a 12012 now.

I will have a think about it, takes a while to save up for either solution!
 

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I do really like the prospect of a Duo as well, the principle of it seems like very logical engineering! I am just not sure if it would be better to just bite the bullet of going to a 12012 now. The size makes no difference to me. Recruit, as a fellow 808 owner, why would you go for a duo 808 over a 12012?
For me the main choice of going for the 808 was it's size and it's musical ability as I am more concerned about musical fidelity than I am movies, although it is a beast when it wants to be, a DUO really will not be that far behind a 12012 in terms of Depth but output at other levels it will surpass due to the extra power available, so for me it is a win win, situation, it is the star of the range IMO.
 

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Discussion Starter #9
I realise we are having the same discussion on two threads. I will just copy and past the stuff i posted i n the other thread onto here!


Thanks for the reply recruit. I fully understand the desire for somethign smaller and more compact. It does make it so much easier from a room layout prospective to have smaller subs! If i wanted a 12012 i would have to sell my current 808 and buy a 12012 which is more hassel than just getting a 808. also given its location i think a stack with its extra height would be more ideal, so i am leaning towards it for that reason!

The extra depth would seem to be marginal at best and i think the other benefits, great headroom and fidelity will be better as at the moment the use of the sub is 50/50 music and movies. I tend i listen to music for 2hours before the wife comes home then we watch a film or TV in the evening for 1-2hours.


I will also add i am really enjoying having a more positive conversation on this forum. I post on the AV forums and everything ends up with a argument with certain people which gets very boring after a while!
 

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I realise we are having the same discussion on two threads. I will just copy and past the stuff i posted i n the other thread onto here!


Thanks for the reply recruit. I fully understand the desire for somethign smaller and more compact. It does make it so much easier from a room layout prospective to have smaller subs! If i wanted a 12012 i would have to sell my current 808 and buy a 12012 which is more hassel than just getting a 808. also given its location i think a stack with its extra height would be more ideal, so i am leaning towards it for that reason!

The extra depth would seem to be marginal at best and i think the other benefits, great headroom and fidelity will be better as at the moment the use of the sub is 50/50 music and movies. I tend i listen to music for 2hours before the wife comes home then we watch a film or TV in the evening for 1-2hours.


I will also add i am really enjoying having a more positive conversation on this forum. I post on the AV forums and everything ends up with a argument with certain people which gets very boring after a while!
Yes, if you already own an 808 then the logical step would be to get a stack or DUO which will then give you the fully balanced sub and the benefits which Ken has discussed earlier which tbh I cannot wait to hear, as I know from experience, with his speakers and subs, when he creates something special, you really do need to hear it for your self to benefit it fully :)

It is also nice to have a proper discussion with people who are passionate about a subject that I also love and enjoy so much, other forums which I know to well always end up in arguments and I know those forums very well myself which is why I left them.
 

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Discussion Starter #11
As i have only been into home cinema kit for about 4-5 years. I have only recently been introduced to M&K and now KK stuff, but from my experience of my KK sub i am perfectly willing to put my trust in if KK tells me the DUO is awesome then he is right!

I live right near FrankHarvey so its a shame that they stopped selling KK as i would imagine i could have borrowed a 808 for a few days to test it vs my 12012.
 

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As i have only been into home cinema kit for about 4-5 years. I have only recently been introduced to M&K and now KK stuff, but from my experience of my KK sub i am perfectly willing to put my trust in if KK tells me the DUO is awesome then he is right!

I live right near FrankHarvey so its a shame that they stopped selling KK as i would imagine i could have borrowed a 808 for a few days to test it vs my 12012.
Yes, I feel exactly the same about the Frankharvey situation, but I believe that it was out of Ken's hands as L Sound are the one's that took that decision to make them a direct sell product :(
 

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I have been using Ken's speakers and subs for about 10 years and will continue to use them as they are considered to be some if not the best for studio's and film makers, but once you get to listen to a full Ken Kreisel speaker and sub package then you are hooked for life :D
 

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Discussion Starter #14
Oh well. At least from my experience Jan at L - Sound seems a good person to deal with and always gets back to you quickly and is helpful with answering questions.

I am not sure if i asked you recruit but i still am none the wiser. When i connect

RCA(AVR)-RCA(808) the AVR trims the so to -12 (green dot position)
RCA(AVR)-XLR(808) the avr trims the sub to -2 (green dot position)

Is it part of the design? Its good news for if i got a DUO 808 as there will still be enough trim left on the subwoofer channel to set them both to the green dot position. I just wondered if there was anything wrong with the XLR or RCA connection to get such a big disparity between the two.
 

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XLR is a balanced connection and therefore the noise floor level is brought down dramatically and this could be why you are getting such better results using the XLR connections over the RCA ones.
 

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Discussion Starter #16
Yeah i originally got the RCA-XLR connection as i much prefer XLR connections due to how snugly they fit together. It also seemed to reduce the slight hum the sub gave out when the AVR is not turned on. So i have been very pleased with it for that.

Maybe the reduced volume is because the if it was a XLR-XLR cable there would be two "hot" pins as such which would give the subs input more voltage which would generate a higher output. These are all wild guesses.

EDIT

An RCA-XLR is still unbalanced due to it only having a single hot pin.
 

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Yeah i originally got the RCA-XLR connection as i much prefer XLR connections due to how snugly they fit together. It also seemed to reduce the slight hum the sub gave out when the AVR is not turned on. So i have been very pleased with it for that.

Maybe the reduced volume is because the if it was a XLR-XLR cable there would be two "hot" pins as such which would give the subs input more voltage which would generate a higher output. These are all wild guesses.

EDIT

An RCA-XLR is still unbalanced due to it only having a single hot pin.
Obviously it is having some benefit, when I get the other DXD808 then I will have to use XLR cables to pass through, so I will see for myself what results they yield when I get round to connecting up :)
 

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Proud owner of a single dxd 12012. Thanks to this wonderful forum and thanks to Ken for amazing product.
 
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