Planar Speaker Asylum

Welcome! Need support, you got it. Or share your ideas and experiences.

Planar Speaker Asylum

RE: Excellent ...

76.220.73.159

In Reply to: RE: Excellent ... posted by Roger Gustavsson on December 10, 2023 at 09:59:37

I tend to agree here, but I'm running a ~50W (@8 Ohm) tube amp right now driving the T-IV's full range and it's sounding good/detailed. If he's going to bi-amp with the Pass amps it -might- be enough if the room is on the smaller side.

I say appx. 50W because the amp is designed for KT-120's and I'm using 6550's instead, so it's output is less than the design spec of 75WPC. As I've stated before, I only need about 15WPC (on 8-Ohm meters) for the room to start feeling 'too loud', however.

Follow Ups:

RE: Excellent ... - Beardy 14:04:33 12/10/23 (6)
Output volume is unarguably related to I^2R. With my DVM I measure typical AC voltages of 5-6 volts at speaker terminals when playing loud. However this meter does not have the temporal response to read accurate values for the peaks, so let me get back to you on that once I have a decent analog AC Voltmeter to play with.

My unfounded belief is that much of this preoccupation with massive power is a reflection of the amplifier architecture required by low impedance speakers. A power supply that can readily provide the current required is feature of a better quality amp. The degradation in sound quality that one might hear from lower power amplifiers may be the impact of shortfalls in the power supply dept.

My expectation is that at `my volumes' there are peaks to perhaps +/-20V, and potentially the impedance of planar may be as low as 2.5 Ohms. This suggests an F5 with a power supply that can give 40V/2.5 Ohms (16A) might do the trick.
However, my wife tells me that on occasion I am wrong.
- RE: Excellent ... - UncleMeat 14:20:05 12/10/23 (5)
  Keep in mind that Magnepans are one of the most capable speakers at producing impulse transients like drum/cymbal percussion. These instantaneous changes in voltage approach infinite wattage/current in the instant they are generated.
  
  The signal path from the source through to the amplifier all have to try to reproduce that signal/current demand, of course at lesser extremes with lower voltages. When it gets to the power amp, that current demand goes way up as it tries to drive the low impedance load (relatively) of the speakers.
  
  So it really depends on the amp, and it's current delivery capabilities to be able to keep those notes sharp/accurate. Magnepans are so revealing that deficiencies of the amp can be heard, where they may not be with a standard speaker that's not 'fast' enough.
  - RE: Excellent ... - Beardy 14:23:23 12/10/23 (4)
    Understood - that echoes my thoughts.
    
    There is always the turbo...
    :o)
    - RE: Excellent ... - andyr 16:14:12 12/11/23 (3)
      As Dennis said: " So it really depends on the amp, and its current delivery capabilities to be able to keep those notes sharp/accurate ."
      
      Maggies are not the only spkrs that sound better when the amp driving them has bags of current-delivery capability. A mate of mine had some stand-mount B&Ws for many years. He first drove them with a very good-sounding Oz-made 40w tube amp. They sounded very nice - if a little bland ... so one day he decided to try a 150wpc ss amp. That made a huuuge difference ... and he thought he was done! Then, a wicked friend brought over his Magtech to try (500w into 8 ohms, 900w into 4 ohms ... and stable into 2!). Russ then bought a Magtech! :-))
      - RE: Excellent ... - UncleMeat 00:50:07 12/12/23 (2)
        
        In Reply to: RE: Excellent ... posted by andyr on December 11, 2023 at 16:14:12
        
        Well, with all forms of conversion to mechanical motion from electricity, it's the magnetic field of the permanent magnets interacting with the magnetic field of the voice coil, or in the case of Magnepans, the linear voice wires. The magnetic field of the wire is generated from the current flowing in the wire. Voltage and current are inter-related but the current (flow of electrons) is what generates the magnetic field.
        
        RE: Excellent ... - Roger Gustavsson 01:16:33 12/12/23 (1)
        
        In Reply to: RE: Excellent ... posted by UncleMeat on December 12, 2023 at 00:50:07
        
        Still I=V/R. As the Magnepans driven active is a pure restive load there is not a lot of currrent running through them. The power amps used by myself will not run out of current but of voltage. They can deliver a maximum peak current of 80 A but that will only be the case with some completely stupid speakers which need to go back to the designing board. With the 4 Ohm basses of a Magnepan peak current may be about 10 A (400 W in 4 Ohm).
        
        RE: Excellent ... - UncleMeat 19:07:25 12/12/23 (0)
        
        In Reply to: RE: Excellent ... posted by Roger Gustavsson on December 12, 2023 at 01:16:33
        
        I think it depends on the amp, some amps spec'd at high voltage/wattage will fall short on current delivery under load with dynamics, which again will create higher than 'average' instantaneous current/voltage demands. A lower wattage amp that can deliver high current can be OK, if it can keep up with the instantaneous demand (at lower volumes, of course).

Post a Followup:

FAQ

Post a Message!

Forgot Password?

Moniker (Username):
Password (Optional):
	Remember my Moniker & Password (What's this?) Eat Me
E-Mail (Optional):
Subject:

Message:	(Posts are subject to Content Rules)

Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:	Automagically notify you when someone responds.

To view your new posting or follow-up, click on the RELOAD or REFRESH button on your browser.

This post is made possible by the generous support of people like you and our sponsors:

Parts Connexion