So you meant new 3R3 value + the cap across will not raise the 10K Hz plus but just decrease what is below 10 K Hz ?
The 10K plus should not be raised indeed.
I just seen that ! This tweeter should be really padded down, it is obvios why the poster is hearing sibilance or fatigue :
I'd pad down all the >4K hz to the 0 dB line. And perhaps the 600/700 hz can cause fatigue too, though it is only 2.5 K hz peak. (or the 300 hz deep due to the front wall/speaker placement).
I'd first try after measurement according the result if similar : the serie R attenuation with perhaps the according shunt value or a serie notch centred to 10 K hz and large enough to reduce the >5K hz on the zero line.
I am not at STereophile of course but this is odd they noted it excelent, I have seen better loudspeakers on measurement that was not liked by them like the Boston Lynnfield 500L which indeed in its forst iteration needed a sligth better treble attenuation.
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Dear temp25,
I am reading all your advices, which greatly help.
While I sometimes attempt to change some component values
of my amplifiers (which is rather simple because they are parallel
single ended), I rarely try to change values of crossover parts
because I feel speakers are much harder for me to understand.
But, after reading your comments, I will try to experiment.
Regarding exotic caps, I tried somewhat expensive caps.
Caps make huge difference in sound. I had tried various
caps for the tweeters. I particularly love paper in oil caps.
I think PIOs generally produces warm sound. Currently, I
use Jensen copper foil PIOs for the tweeters. I tried some
silver foil caps for the tweeter to see if it can reduce treble
but found the sound was even thinner even though the
sound was incredibly clean.
I have read that you have a tube amp
Have you checked the performance in terms of Freq. response?
Can you explain this amp?
One consideration around a possible the peak on mid-high frequency?
On tw crossover there is a resistor, before the network, maybe a little increment of the value can help.
ps= which version is your 800?
Walter
Dear diyiggy,
I think you are spot on for my case.
Sooner or later, I have to measure the speakers (and amps) myself.
But, I think the above frequency response (posted by Seterophoile magazine)
explains what I have been hearing.
I think it is somewhat necessary to tame down high frequency (say 7kHz and up)
and slightly boost up 1~3kHz. I am not sure but I feel that those 1~3kHz range
is related to the reason why I feel the violin sounds are somewhat unnatural.
Earlier yesterday, I said that I am unsure whether I can increase 2~3kzhz and
decrease higher frequency (say 7kHz and up). If I can do that, I might be able
to solve the problem.
In any case, I will keep experimenting, this time with crossover or tweeters too.
Hi,
First of all, the amps are dual mono parallel single ended triode.
The output tubes are 211. The input tube is 12au7 (or 12ay7)
and two 6SN7 tubes as cathode followers. The amplifiers employ
interstage transformer coupling instead of capacitor coupling.
In place of 12au7, I often use 12au7, 12BH7, 6072, E80CC,
or even 6SN7 (with adaptor). Also, in place of 6SN7s,
I use 6SN7s or 6F8Gs (with adaptors).
I think people do not use SET or PSET to drive Matrix 800
because the low wattage. However, 211 SETs or PSETs
matches extremely well with Matrix 800.
In the past, I used dual mono SET with 211 tube to drive Matrix 800.
That combination produced wonderful sound. That particular
amplifier used 6SN7 as the input and 6SL7 as the cathode follower.
When I used that amplifier, I could produce reasonably less harsh
highs with Tungsol 6SU7GY7 in the position of 6SL7. I believe that
6SL7 (and 6SU7) made the sound less fatiguing. At that time, I
experimented tweaking the amp a little bit and changed 6SL7
with 6SN7 and found that the sound was way too fatiguing with
exaggerated highs. So current problem could also be related to
the characteristics of 6SN7 tubes.
The old SETs were broken about 7 years ago. I could have repaired them
but I just went ahead a new set of amps. So the current issue is more
salient with my new PSET. Also the issue depends on the choice of tubes.
Among all 6SN7 variants, I feel tungsol 6F8G is the best.
It sound uncomparably clean and detailed. But, it somewhat lacks richness.
So, when I use 6F8Gs, the high frequencies sound more prominent.
I bought a microphone (UMIK-1) to measure the whole system.
But, even after buying it, I tend not to use it yet. After listening
to many of you, I will have to use it soon.
By the way, I don't have a device to measure the amplifier
frequency response alone.
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Ok
do you have a schematic?
One issue that can be found is the non perfect match with interstage , or the non high quality of trafo.
So a peak, maybe, happen in the mid-high frequency.
If you have a good sound card you can test it with Multitone software taking care on the signal level, directly from speaker connection or a simply resistor to compare the results
If you change the tube connected with interstage with some similar to the original it is possible that due the different Rp the response will change
Walter
I would add a notch like one added on this sim to produce the flatter gray line response. That's where I would start. This only takes a small coil, cap, and resistor, and the filter can be fine tuned. It's not all, or nothing.
I have two friend with 800D, two versions.
Plus other with 802D
With amps done by me.
It is not a simply speaker but with great performances
One photo of an old configuration ( my friend pass away few years ago)
nr. 4 mono amp 4 x KT150 + tube crossover.
The reservoir of power , in my opinion, is mandatory for this speaker
Without knowing the output impedance of the tube amplifier it is difficult to be certain, but many tube amps have a relatively higher output impedance than the transistor amps generally available. Looking at the impedance vs. frequency graph published by Stereophile you can see the speaker has low impedance ( 3.5 Ohms ) in the bass that transitions to a high impedance ( 11 Ohms ) at 1 kHz for the midrange and tweeter. So a high output impedance amplifier will produce a non-uniform power output across the range based on the speaker impedance. The low impedance range getting less power and the high impedance range getting more. So with a high output impedance amplifier one would expect the entire range above 1 kHz to be accentuated relative to the rest with exception of the peak at 45 Hz.
This "feature" has kept many boutique audiophile stores in business as the sound of this speaker ( and others with impedance curves like it ) is manipulated by connecting amplifiers with different output impedance values and thin vs. thick speaker cables. The effect being much like turning the loudness control up when using high output impedance amplifier, as the bass at 45 Hz and treble above 1 kHz will be accentuated. Speakers with a flat impedance vs. frequency do not exhibit this behavior.
Fig.1 B&W Matrix 800, electrical impedance (solid) and phase (dashed). (2 ohms/vertical div.)
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Dear Charles,
Yes, I am using parallel single-ended triode amp.
Unfortunately, I don't have a device to measure the
frequency response of the amplifier alone.
I can't actually yet understand what you explained to me.
The output transformer is Tango X-10s, which has rated output
impedance of 10kOhms. Since I am using two 211s per channel,
the effective output impedance is 5kOhms. So I connect the
speakers at 8Ohm terminal of the output transformer. This is
all I did for impedance matching. I am not sure but I guess you
are explaining that I have to do something beyond this for
correct impedance matching.
I will try to study further about your comments.
That's doable. If you were to increase the tweeter cap values about 15%, and change the padding resistor to a larger one, that would probably do it. You would need to measure, but that's probably about what it would take to do it.
If you want to experiment, it doesn't have to be using the speaker. You could mount the tweeter on a similar size board, and play with the tweeter x-over. Sim software could even predict changes so that it would be easier for you.
Your SE tube amplifier with an output impedance of a few ohms will have a non-linear frequency range that will change from speaker to speaker depending on the speaker impedance. The higher impedance parts of the band will get louder. A transistor amplifier with low output impedance is required to measure the frequency range and impedance of the speaker.
Have you tried how your B&W sound with a transistor amplifier? Classic, DC coupled, push pull output, AB or A class.
The speakers are connected to 4Ohm outputs at the amps.
As I explained above, the output transformer is Tango X-10s,
which is rated as 10kOhms transformer.
I found people generally employ the load line of 10 ~ 16kOhms
for 211 tubes. Since the amp uses two 211 tubes, the output
transformer must be rated to be 5-6kOhms. The designer of
the amplifier took 5kohm load line.
Tango X-10s has output terminals at 4, 8, 16Ohms. Since equivalent
load is 5kohms, the equivalent speaker terminal outputs are
2, 4, 8Ohms. I connected the speakers at 4Ohm terminals.
According to your explanation, it is ideal to use two
amplifiers to each speaker, one for woofers and the other for
midrange and tweeter. If this is necessary, I might consider
adding two more mono blocks to drive midranges and tweeters.
Could an LCR, externally at the speaker connections be used to improve the speaker impedance? I did this with one of my speakers, and a solid state amp not long ago. Cool thing was, it was connected with banana plugs for easy A/B testing. Actually, it looks to me like just a CR would suffice, but I know nothing of tube amps, and I'll risk my amps for a test, but smarter guys than me should consider the potential problems, if any. Sure would be easy though.
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First of all, thanks for instructing me with something I didn't know.
I will study and think about this issue more.
Unfortunately, I haven't been using solid state amplifier for long time.
So I didn't have a chance to try Matrix 800 with solid state amps.
While I started this thread to know some technical specs I have to
consider for tweeter replacement, I learn great deal from various
people.
The X10s is for one 211 because it has 10 kohm
With two 211 in Pse you need 5 kohm to match correctly ( theory)
With 10k and 4 ohm you will have a better DF ( but less power) but this is not the problem .
Walter
Think to buy a good sound card and use a software to test the chain.
It is not a hard job
Walter