Zero Distortion: Stacked Quad 57s

[Dogberry]

Stacked 57s or a pair of 2905s or 2912s? Anyone heard both and able to comment?

 

[MRJAZZ]

Great site and one of the best resources on plasma tweeters. Please keep in mind that the lower the crossover point the lower the efficiency of the Acapella plasma tweeter. In order to maximize their efficiency I use them at the highest recommended crossover point of 8.5KHz.

What's their efficiency at a 8.5 Khz crossover?

 

[Carlos269]

What's their efficiency at a 8.5 Khz crossover?

They are 91dB over 8.5KHz. Plasma tweeters are not very efficient.

 

[the sound of Tao]

All that silver and all that bespoke… it’s a very cool system, thanks for sharing it Ked.

 

[dave slagle]

No need to be afraid of well designed and executed equalizers.

agreed 100%... It can even be argued that having multiple tonearm cartridge combos for different flavors is simply a means of adjusting EQ. I suspect the bulk of the bad name given to equalizers (and tone controls for that matter) is due to their implementation and not the underlying concept.

I used to be an anti-eq'er and a card carrying member of the cult of straight wire with gain. Then one day I experienced a cello palette. In the flat position it did remove some of the magic of the music but once engaged and some shaping applied the net result was substantially better. My take away from this was committing the crime of using EQ was well worth the risk of scorn from fellow audiophiles.

sorry for the veer off topic and we can now return to your regularly scheduled programming.

dave

 

[Ron Resnick]

ultimately comes down to what you are trying to achieve

+1

If the goal is replication of some mythical straight wire with gain then I agree with your premise.

This likely is the conceptual goal of an audiophile whose high-end audio objective is:

"2) reproduce exactly what is on the master tape or digital file"

if the goal is creating the most enjoyable individual listening experience

This is Objective 3) "create a sound subjectively pleasing to the audiophile"

then it can be argued that every piece in the chain is a tone control and we are all simply twiddling EQ knobs

Under this view and with Objective 3) equalizers make total sense.

 

[Ron Resnick]

Kedar, thank you for this very cool report!

I think that that piano sound is some of the most realistic piano sound I have heard in a video.

 

[Ron Resnick]

It can even be argued that having multiple tonearm cartridge combos for different flavors is simply a means of adjusting EQ.

Hello Dave,

I think this doesn't recognize that tonal balance/EQ is merely one of the sonic reasons some audiophiles like having more than one cartridge/tonearm combination. Other sonic reasons include differences in dynamics and in transparency.

 

[Carlos269]

+1


This likely is the conceptual goal of an audiophile whose high-end audio objective is:

"2) reproduce exactly what is on the master tape or digital file"

The issue is that first there is no way for the audiophile listeners to verify or confirm the fidelity of their system to the master tapes. Even if the master tapes are at hand, verification would require measurements from end-to-end, from magnetic tape to ear, in order to authenticate.

This is Objective 3) "create a sound subjectively pleasing to the audiophile"


Under this view and with Objective 3) equalizers make total sense.

In essence this is what we all are doing, even those “pius” purists audiophiles, they just don’t realize it, or understand the elements at work.

 

[bonzo75]

Stacked 57s or a pair of 2905s or 2912s? Anyone heard both and able to comment?

57s

 

[Carlos269]

agreed 100%... It can even be argued that having multiple tonearm cartridge combos for different flavors is simply a means of adjusting EQ. I suspect the bulk of the bad name given to equalizers (and tone controls for that matter) is due to their implementation and not the underlying concept.

I used to be an anti-eq'er and a card carrying member of the cult of straight wire with gain. Then one day I experienced a cello palette. In the flat position it did remove some of the magic of the music but once engaged and some shaping applied the net result was substantially better. My take away from this was committing the crime of using EQ was well worth the risk of scorn from fellow audiophiles.

sorry for the veer off topic and we can now return to your regularly scheduled programming.

dave

Hello Dave,

I think this doesn't recognize that tonal balance/EQ is merely one of the sonic reasons some audiophiles like having more than one cartridge/tonearm combination. Other sonic reasons include differences in dynamics and in transparency.

To begin with, the Cello Audio Palette is a graphic equalizer, with low Q = large bandwidth around the center frequencies. I own the Cello Audio Palette MIV version and use it in my WAAR system with the system-Remastering process. While it is a nice quality piece of equipment that does what it claims to do, there are mastering equalizers that offer greater functionality, more effective sound sculpting features.

As I have mentioned previously, dynamics and transparency are sound quality attributes that are a function of frequency, amplitude and phase. Therefore degrees dynamics and transparency can be adjusted through frequency-response contouring or adjustments.

 

[Audiohertz2]

This becomes a very slippery slope and ultimately comes down to what you are trying to achieve. If the goal is replication of some mythical straight wire with gain then I agree with your premise. However; if the goal is creating the most enjoyable individual listening experience then it can be argued that every piece in the chain is a tone control and we are all simply twiddling EQ knobs with each and every equipment swap.

dave

Actually thats what i thought i had implied with my response , by EQ of each track you are balancing the playback to your best representation as you think it should be. It does make a big difference , tone controls can be used to a great advantage if done right, the only issue is what form of playback accuracy are you seeking , correct to the input signal or correct to your “taste” of adjustment and tone ..!


Regards

 

[Audiohertz2]

No need to be afraid of well designed and executed equalizers. Crossovers, both active and passive, are fixed filters while equalizers are adjustable filters but they are both filters so if you are going to take aim at the use of equalizers you need to understand that response shaping is already taking place in the crossover. No need to fear equalizers or think of them differently than crossovers. The crossovers allowed the designers to “voice” the speakers and equalizers allow the end-user to “voice” the system in the most basic of ways. There are far more advance and effective ways to tailor the sound of a system than with an equalizer but at least equalizers are sound sculpting tools, even with their limitations.

Again my response was pro EQ if necessary not against, then apply the usual disagreement on how to do it especially with already under powered systems before one starts applying EQ boost ..


Regards

 

[Audiohertz2]

They are 91dB over 8.5KHz. Plasma tweeters are not very efficient.

Whats the impedance @ 8.5K and you mean sensitivity not efficiency.. ?

 

[Carlos269]

Again my response was pro EQ if necessary not against, then apply the usual disagreement on how to do it especially with already under powered systems before one starts applying EQ boost ..


Regards

You make a very good point regarding applying EQ and power availability. Not only will the system demand more power if the net EQ is boost, but more importantly, even if the power demand is met, the resulting sound can lead to speaker driver damage if the speaker or drivers are being driven outside of their design specifications. The end-user needs to be intelligent about adjusting any parameters prior to enabling any equalization boost. It is always recommended to cut other frequencies as it often achieves the same results as boosting the target frequencies.

 

[Carlos269]

Whats the impedance @ 8.5K and you mean sensitivity not efficiency.. ?

The Acapella ION TW 1S plasma super-tweeters have a potentiometer knob that adjust the sensitivity of the modulation to the input level. I meant as I wrote, efficiency, at acceptable levels of distortion:

 

[Kingrex]

it’s mentioned there, triamped and who built it

I'm sorry bonzo. I only saw the play button first time and missed the link. Reading while traveling. Thanks for the write up.

 

[Kingrex]

Hey,

JP is fighting the registration spam-bots so until he can respond and I will handle many of the technical questions in the meantime.

The speaker cabinets are made by a craftsman in Maryland to this specific project.

In the original '57 design a single amplifier drives an input transformer that steps the signal up to feed a high impedance passive crossover which directs the music to the appropriate panels.

JP's 57's use a line level crossover integrated into a pair of push pull 300B amps loaded with step-up transformers tailored to the panel frequency response. JP has added some additional subtle crossover shaping to the panels directly. One key aspect is the dual 300B amps reside in the base of the speaker to avoid the need to step down the voltage to drive speaker cables to then step it back up to drive the panels. In a typical situation the output of a 300B will see a 25:1 step-down to get to 'traditional' speaker level. This is then stepped back up by a factor of 70 for the highs and 280 for the bass to drive the electrostatic panels. This instance has a pair of 300Bs feeding a 1:2 output transformer to drive the HF panels and a second pair feeding a 1:8 to drive the bass panels.View attachment 122529View attachment 122530

dave

Well done amplification.

 

[Kingrex]

agreed 100%... It can even be argued that having multiple tonearm cartridge combos for different flavors is simply a means of adjusting EQ. I suspect the bulk of the bad name given to equalizers (and tone controls for that matter) is due to their implementation and not the underlying concept.

I used to be an anti-eq'er and a card carrying member of the cult of straight wire with gain. Then one day I experienced a cello palette. In the flat position it did remove some of the magic of the music but once engaged and some shaping applied the net result was substantially better. My take away from this was committing the crime of using EQ was well worth the risk of scorn from fellow audiophiles.

sorry for the veer off topic and we can now return to your regularly scheduled programming.

dave

Veering off a little more. Isn't that a Schiit EQ. Are they any good?

 

[JohnP]

Veering off a little more. Isn't that a Schiit EQ. Are they any good?

Yes, it is a Schiit EQ. I thought it improved the sound when used but was not in the same league as the Cello or Dave’s EQ.