What is the reasoning behind this statement. I think that this is not correct, but you keep saying it, so I would like to know why you think this.
Nice! Waveguide gives 6dB boost at 2kHz. This means that clever choice of HP capacitor gives flat response and good looking curve. But then we still have increasing excursion (and distortion) at low frequencies. This is why waveguide tweeters should have something like LR4 acoustic slopes with synchronization to their natural roll-off.
Reference to low end excursion/distortion here by J Kreskowsky. This is about dipole mid but the basic problem is same NaO Note II RS Details
An externally hosted image should be here but it was not working when we last tested it.
Like Charlie I think that phase match problem is the same at every listening volume. By the way we have new evidence that phase discperancies are really heard AES E-Library Sensitivity of Human Hearing to Changes in Phase Spectrum
well, phase problem is the same at all SPL
but at higher SPL it is 'masked' by the increasing distortion
at low SPL it is just annoying
a bit like seventies Japanese amps 😉
with improved better phase it will sound great at low SPL
and yes, it will also be less distorted at higher SPL
this is when you experience nice airy sound, almost regardless of SPL
btw, if you only had a distortion problem, it would sound great at low SPL, and not so at higher SPL, which he claims it does
it is a phase problem
that is the case
but at higher SPL it is 'masked' by the increasing distortion
at low SPL it is just annoying
a bit like seventies Japanese amps 😉
with improved better phase it will sound great at low SPL
and yes, it will also be less distorted at higher SPL
this is when you experience nice airy sound, almost regardless of SPL
btw, if you only had a distortion problem, it would sound great at low SPL, and not so at higher SPL, which he claims it does
it is a phase problem
that is the case
I've tried to model a new filter and have achieve a little higher XO point, but now the phase starts acting up - at least in the simulation.
So what is most important:
I how the attached pictures illustrates my point.
I.e. where is it of most importance that the green line meets the blue line?
So what is most important:
- Change phase at the same time/frequency ?
- keep the same the same between the two (three) drivers)
I how the attached pictures illustrates my point.
I.e. where is it of most importance that the green line meets the blue line?
Attachments
tweeter level is probably too high
if you get it down you might notice that xo point is moving
and may be why it shows phase issues
if you get it down you might notice that xo point is moving
and may be why it shows phase issues
This is a TMM 2-way, BSC compensated by near-wall placement. If I understand the simulation above right, we see crosspoint between a single midbass and tweeter at 1,8kHz. Parallel midbasses make the upper line and then real acoustic crosspoint of total system is something like 2,2kHz.
Sorry but I don't know passive xo desing well, I can't say anything helpful about phase matching. Is this a Boxsim simulation? Is the effect of waveguide set in the simulation?
Sorry but I don't know passive xo desing well, I can't say anything helpful about phase matching. Is this a Boxsim simulation? Is the effect of waveguide set in the simulation?
All most.
Actually both mid-bass drivers are in the simulation.
Yes it is Boxsim and the waveguide gain is also in the simulation; hence the ~90 dB sensitivity.
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In the range where woofer and tweeter contribute to the overall SPL (1 kHz - 4 kHz). The phase in your latest simulation actually looks very good.
I see you now have changed the woofer to AL130M. I would like to verify your simulation results, but you need to give more reliable information regarding woofer model, waveguide model, cabinet dimensions, box volume and baffle layout. A picture would help very much and answer most of the questions.😉
another amp ?
Would be interesting if you could borrow some other good quality amp and have the same experience as mentioned in post 1.
I have several amps and my speakers sound totally different on most of them
Cheers ,
Rens
Would be interesting if you could borrow some other good quality amp and have the same experience as mentioned in post 1.
I have several amps and my speakers sound totally different on most of them
Cheers ,
Rens
I'm not going to spend time on this, but Visaton publish an almost identical speaker with a 2.2kHz third order tweeter crossover:
Boxsim Projektdatenbank Standcouplet WG
I really don't know how Boxsim accounts for the round waveguide here, since it's not in my driver files, but it all seems to work even with the AL130M substituted. 😎
Boxsim Projektdatenbank Standcouplet WG
I really don't know how Boxsim accounts for the round waveguide here, since it's not in my driver files, but it all seems to work even with the AL130M substituted. 😎
There may be another cause.... The volume pot. A standard volume pot will lose its linearity at lower settings. Its loses its dynamic sound when played lower. I learned this factor from a tech/modifier and others. I find it interesting that one solution is coming from Arcam. They now use a high quality linear digital/analogue volume pot in their new A19.
Here is a blurb from a review I found in my search for a better potentiometer..
The A19 uses a Texas Instruments PGA2311 volume control—the same one found in Arcam's top-of-the-line FMJ AV888 processor, and claimed to deliver an impressive 120dB signal/noise ratio and very low total harmonic distortion of 0.0004%. According to Clarke, these figures are more commonly found in "highly esoteric and very expensive dedicated preamplifiers." Clarke also noted the A19's high-quality printed-circuit board and the careful layout of its audio circuitry.
Arcam FMJ A19 integrated amplifier | Stereophile.com
Arcam FMJ A19 integrated amplifier | Stereophile.com
But, that's not enough in itself. Here is the subjective listening test results.
Sound
The first thing I noticed and enjoyed about the Arcam A19 wasn't sound at all, but an absence of sound: As mentioned above, the A19 was very quiet. With the input set to Phono, the volume knob turned up high, and an ear positioned close to one of my Wharfedale Diamond 10.1 speakers, I heard silence: no hum, no buzz, no nothing—exactly what I'd hoped for.
I was again reminded of Simaudio's Moon i3.3, which had most impressed me with its super silent backgrounds and excellent dynamic range. So I decided to conduct a test: With a record playing and the volume set to a normal listening level, I made myself comfortable and slowly began reducing the amp's volume in an effort to see how low it could go before the music lost its ability to engage me. In my previous, smallish (10' by 13') listening room, my 40Wpc NAD C 316BEE was good at this game, sounding reasonably dynamic and colorful even at very low levels. In my current room, which measures about 18' by 20', the NAD does not perform as well: Music fades into the background rather quickly, and I find myself wanting to raise the volume in order to restore the music's life. No big deal. With the Arcam, however, I was surprised by how low I could go before feeling the need to turn back. In fact, even at extremely low levels, the music remained compelling—clear, dynamic, and colorful, with natural-sounding sparkle to the highs and good punch to the lows.
Arcam FMJ A19 integrated amplifier Page 2 | Stereophile.com
The first thing I noticed and enjoyed about the Arcam A19 wasn't sound at all, but an absence of sound: As mentioned above, the A19 was very quiet. With the input set to Phono, the volume knob turned up high, and an ear positioned close to one of my Wharfedale Diamond 10.1 speakers, I heard silence: no hum, no buzz, no nothing—exactly what I'd hoped for.
I was again reminded of Simaudio's Moon i3.3, which had most impressed me with its super silent backgrounds and excellent dynamic range. So I decided to conduct a test: With a record playing and the volume set to a normal listening level, I made myself comfortable and slowly began reducing the amp's volume in an effort to see how low it could go before the music lost its ability to engage me. In my previous, smallish (10' by 13') listening room, my 40Wpc NAD C 316BEE was good at this game, sounding reasonably dynamic and colorful even at very low levels. In my current room, which measures about 18' by 20', the NAD does not perform as well: Music fades into the background rather quickly, and I find myself wanting to raise the volume in order to restore the music's life. No big deal. With the Arcam, however, I was surprised by how low I could go before feeling the need to turn back. In fact, even at extremely low levels, the music remained compelling—clear, dynamic, and colorful, with natural-sounding sparkle to the highs and good punch to the lows.
Arcam FMJ A19 integrated amplifier Page 2 | Stereophile.com
I ordered one for myself and am awaiting delivery.
Wishing you the best, Gene
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How high volume is "high volume"? The voice coils could be getting hot, changing the characteristics of the passive XO as the DC resistance goes up. Similarly, the inductance will change as the bass coil flutters around in the magnetic gap. Therefore, a source of 'crispiness' could be IM distortion. The bass modulates the loudness of the treble, giving the highs a dalek-like zing to them.
It could be many things. What cores do the inductors have? I doubt they'd be saturating, but it's another possibility, and and crosstalk could be another source of IM distortion.
It could be many things. What cores do the inductors have? I doubt they'd be saturating, but it's another possibility, and and crosstalk could be another source of IM distortion.
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