H J s system !

[andromedaaudio]

I can't see any connection between your praise of FM and trying out Hegel.

Incidentally, one dealer offers FM demo devices on audiomarkt.

When i buy FM i want the box with the big resolution series screen lit up .

FM lower priced gear is Single ended or a combination of both like the 245 pre amp but not fully balanced ( afaik)

So afaic it starts with a FM 411 mk3 with 256 RC pre amp , linearizer can be added later according to Manual Huber the linearizer is the " Thing "to buy from FM acoustics .
Afaik a 268 is a 266 with built in 233 linearizer

FM 411 mk3





FM 256 RC




Linearizer 233

 

[andromedaaudio]

I changed interlinks today .

The old ones served me about 20 years .
The new ones are slightly more expensive at 37.50 euros.
For 5 meters

But .....they have a anti interference filter lol

I ll connect the meitner with XLR as well see what the difference is.
Placing the meitner close to the Hegel .

 

[andromedaaudio]

SUBs casings were ready just picked them up
Made from HPL of course.
Internal stiffeners support internally the Magnet to reduce/ eliminate Resonance.

These are passive subs with internal low pass filter and can be used with any speaker when the sensitivity matches.

Sub sensitivity is 92 db .

If the main speaker has a 92 db sensitivity then each speaker needs a SUB.

If the main speaker has a 89 db sensitivity
.one SUB is sufficient

But a +- 2 db variation is acceptable because :


Speaker sensitivity can vary across different frequencies. 1 kHz is a common frequency for measurement.

 

[andromedaaudio]

Some experimentation .
It functions not strictly as a bass - sub .
It also plays higher freqs. supplementing the bas - mid freqs. acting as a centerchannel almost
Interesting sound ,it completely fills the innerspace between the main speakers
This is the 320 mm papersandwich / foam version woofer not paperpulp for extra stifness.

The signal i just take from.either the left or right speaker, best result is when the sub is exactly in center slightly behind the main speaker plane / equal distance to the listener

 

[andromedaaudio]

And the 12 inch Nomex kevlar woofer..
This is a fantastic woofer

 

[andromedaaudio]

And the winner is the Nomex kevlar woofer , a more clean / controlled sound .
I have tested with the CAT pre / Hegel power amp HT theatre through put and the Hegel H590 as an integrated . amp
With the Tube pre a more warm sound but the Hegel is more transparent / controlled , very nice integrated amplifier
I ll be selling the CAT pre amp too .
My next step up will be FM acoustics (likely also the last upgrade ) just music

 

[andromedaaudio]

Just after assembly. , playing organ CD

My biggest bang for buck system .( small black speakers and SUB )
Sliced paper mid and papersandwich foam SUB .

Hegel H590 and the Meitner MA2 DAC .
And of course the Tape decks .
Sounds very neutral / good for the money

 

[Audiohertz2]

Question , why don't you countersink and flush your drivers..?

 

[andromedaaudio]

Question , why don't you countersink and flush your drivers..?

Couple of reasons :

i can keep costs low and i can keep the weight low / easy to handle , believe me constantly handling heavy speakers can be tiresome .
I now keep the material thickness as thin as possible
Sunken drivers would require at least 18 mm HPL ( more costly/heavy ) to keep the material thick enough at the flange regarding stiffness


The main reason however is that the Company who made the original XPE required that i had to produce in large numbers in order for them willing to work with me , which is not an option at moment.
The company i currently work with is also a large company / good partner but very flexible in that regard

13 mm HPL ( glued in miter joints ) with internal bracing is very strong and stiff enough to my taste .

Future XPE models can thus be made much cheaper then the Orginal version as they will also be made from thinner HPL .

FYI im in talks to be at the Brussels Hifi show in November , so there is a potential / good chance i will be demonstrating there.

Mainly showing with Digital but of course i will bring 2 tape decks and some of my best tapes .

 

[Maxim]

Question , why don't you countersink and flush your drivers..?

Good question, especially for tweeters.
If tweeter in not flushed, diffraction will cause unwanted peaks/holes in 3-5kHz.

 

[andromedaaudio]

Good question, especially for tweeters.
If tweeter in not flushed, diffraction will cause unwanted peaks/holes in 3-5kHz.

FR is excellent of this Ls +- 1,5 db on axxis in this range .
I measured this many times from all angles (on axxis 0 degrees - 60 degrees )
I agree a curved baffle would be better , but then your looking at a Moulded design ideally / very expensive to make

 

[andromedaaudio]

Good question, especially for tweeters.
If tweeter in not flushed, diffraction will cause unwanted peaks/holes in 3-5kHz.

Look/ Zoom in at this graph .
You re gonna find very few Ls on the market with this kind of flat response in the 1 khz - 8 khz region.


1 khz - 8 khz +- 1 db

 

[Maxim]

Look/ Zoom in at this graph .
You re gonna find very few Ls on the market with this kind of flat response in the 1 khz - 8 khz region.


1 khz - 8 khz +- 1 db

make a short window (3- 4ms) in impulse response and change 1/3 to unsmoothed, then you'll see all the truth

 

[andromedaaudio]

make a short window (3- 4ms) in impulse response and change 1/3 to unsmoothed, then you'll see all the truth

I never use unsmoothed , unworkable .
Then you have so much dips and peaks over the whole freq range that you cant see the forest for the trees .
1/6 and 1/ 12 i do use


Show me a unsmoothed flat Ls response ?

 

[Maxim]

Here it is: short window - 7,6-2,7= 4.9ms measurement window what allows to avoid floor/ceiling reflections causing dips and peaks.
With short window you measure speaker - only direct sound what speaker do.
With full window you measure sum of speaker response and wall/floor reflections.

 

[andromedaaudio]

What speaker is that ?
Do you have a picture ?
Looks more like copy paste to me certainly in the bassregion.
For example the flatline from 30 - 20 can never be that flat

 

[Maxim]

What speaker is that ?
Do you have a picture ?
Looks more like copy paste to me certainly in the bassregion.
For example the flatline from 30 - 20 can never be that flat

With short window you cannot get measurements on LF.

The graph attached is how speaker performs from 200Hz and up (200Hz is 1.7m - first reflection wave length).

To get estimates on LF you should follow this article Testing Loudspeakers at low Frequencies with CLIO (Paper – by Dr. Joseph D’Appolito)
Not an easy and it is just estimate. To get 100% right result you need an-echoic chamber, but D’Appolito approach works quite well.

What speaker is that ?
The measurements graph is gated measurements for custom built based on SB Acoustics Textreme woofers with Beryllium tweeter:
1m on tweeter axis with speaker on a stand:
SB Acoustics Rinjani Tx Textreme SE Speakers with Berrylium tweeter - Finetuning by StereoArt

 

[andromedaaudio]

I only use measurements seriously from rougly 400 hz and up bass i design by woofer specs and listenening ( and expirience )

Your graph shows a - 8 db point at 20 hz .
Thats not possible your graph looks flawed .
its a 6.5 inch woofer .

This is the small woofer you re using with this woofer size your looking at a Fs of 29.3 hz .

Looks to me you did a whole lot of sanitizing in your measurement
You state 44 hz in your advertizing specs , at 50 hz this woofer is - 14 db and is breaking up so bad its not usable output / its not in phase anymore , you see nothing of that is your graph , in your graph you see a smooth line going down to - 8 db at 20 hz

 

[Maxim]

I only use measurements seriously from rougly 400 hz and up bass i design by woofer specs and listenening.

Your graph shows a - 8 db point at 20 hz .
Thats not possible your graph looks flawed .
its a 6.5 inch woofer .

With this woofer size your looking at a Fs of 29.3 hz .

This the woofer you use , looks to me you did a whole lot of sanatizing in your measurement

Do not look on LF if measurements if they are with gated window. You need to cut everything under wavelength of fist reflections.

To get estimated speaker response please follow D’Appolito approch for Clio - nearfield and far field estimates.
Approach in not new, it is widely used around the world, for example Stereophile use about same "complex sum of near and far field" in they mearurements.

If you do measurements without gating, you get a sum of your room response with a speaker in a certain location and speaker itself.
In other room of if speaker in different location it may look different like this:

Graph is for same speaker but in a different location and with different room treatment. You may see that the difference in some areas are high upto 6dB, and from that kind of measurements you do not know what is real speaker response.
Green is speaker gated, red and blue ungated with 1/6smoothing in different locations and with different room treatment.

As you see room reflections add on the midrange some 3db in the areas where room "rings".

To see what is real response for unflushed s flushed tweeter in your design you should gate measurements.

 

[andromedaaudio]

Approach in not new, it is widely used around the world, for example Stereophile use about same "complex sum of near and far field" in they mearurements.

This is not presenting the reality its assuming and then drawing a line accordingly .
Fabricating something

I have measured Ls in may be 5 - 6 different rooms i measured ALL AROUND THE ROOM .
I design Ls as i think is suitable , you do/ measure as you please .

I use HPL by the way , not cheap MDF
A lot of musical energy will simply dissapate in your housing.

You should listen if you get a chance to Bass reproduction coming from a Braced 13 mm HPL cabinet , compared to your 18 mm MDF housing .
Different world altogether.

Or listen to a piano recording , the decay of a note is on a complete different level with a HPL ( phenolic resin based) cabinet