swenthehornmaker

It's a long time since my last post. Sorry for that but there was simply to much work. I'd like to show you some of the new developped Parts. In 80 days our new System "The Reference" supportled by "The Room" will be shown the first time. Also the definitely biggest passive X over network ever build. I will post some updates the next week's. Best Regards S

The simple answer is, you can't hear them. The main reason that the human ear / brain can recognize them is that usual motors creating pole jolts. The motor we use, is 100% free from it. In 8 weeks I will post some interesting measurements. And the 900.000 corrections per rotation are just a theoretical amount. The written program in the micro controller / axe generator does just intervent, if it's necessary. The 30Kg platter is doing the rest by its own moment of inertia.

The corrections per rotation can be switched down to less than 1000;-) But my philosophy is "Better to have, than in need"

The idea was to develop a turntable without considering the final design. A 100% "form follows function" development. Attached are some basic informations and specs about it. - Horizontally and vertically operating air bearing with an accuracy of concentricity of 0.09µm. Additional delrin axis with manually adjustable pressure to transfer resonances produced by play back to the sub chassis. - Sub chassis with pneumatic and adjustable a-periodic dampers. Double chambers. - Play back platter manufactured from POM, completely decoupled from the driven platter, which is manufactured of a mix of metals and multiple liquid compounds. That assures that no disturbances generated by drive mechanism can reach the pick up. Also the play back platter has a very low ability to store energy. - Tone arm base is constructed in a way, that the tone arm is decoupled from the sub chassis with specially designed spikes, but also stays in exact stable position. All three tone arm bases with completely adjusted tone arms can be exchanged in less than a minute, without loosing the adjustments. - All components optimized for freedom of resonances and reflections. Passive string / belt driven motor unit: - Extremely accurate and disturbance free drive system with a pulley of 16,775 cm diameter which also acts as a fly wheel. Active micro controller drive: - The direct drive motor uses a two phase torque motor with implemented air bearing. This motor uses 18.000 control and measuring points per rotation to achieve the perfect and stabil speed. By interpolalation with a microcontrol-generator , we reach 900.000 possible corrections during one rotation. - Wow and Flutter of 0.002 in direct drive mode and 0.02 in case of the belt driven motor. - Self-resonance of approximately 1.5 Hz. To make it clear, the owner can switch from the direct drive to the belt drive and back during the play back. Both drive options using the same size bearing.

Do You, by any chance have the TSP of Altec 515. I would like to compare data for Qts. The basic parameters we measured by ourselves. I will look at the weekend thru my notices on the MacBook.

Nominal impedance is 8ohm. Attached you can see a system that we also build around 6-8 years ago. In rid one we where using 8 brand new original 515B. Not the GPA shot. The search for the 8 units was 18 month. These are 2 concrere horns. They are around 12000 Kg. https://trshow.info/watch/f2SFY9zt6Xw/deckenhorn-nach-j-hiraga-mit-satohorn-von-hornsolutions-de.html

Impulse response measurements of Horn speakers are not very meaningfull. Therefore we just take impulse response measurements of the single drivers in a pwt

18sound MB606, which is very near to the 515B in TSP. That's the perfect match for a front loaded horn without back compression chamber. Ok, there is a back chamber, but it's 12.500 Liters;). The 666 we build with neodymium magnets which are specifically developed for this driver. In the gap we create 2.4 Tesla. That's impossible with any other magnet or FC. At least in case of a midrange driver. 8ohm Bass driver, what gives 2,66 Ohm.

That's the look into one side of my bass horn. All in all there are 6x15". The other one shows the 666 Compression driver. I would call it the heart of my system

Absolutely correct. Measuring is for developing and basic setups. That's all

Impulse response measurements of Horn speakers are not very meaningfull. Therefore we just take impulse response measurements of the single drivers in a pwt

In maybe 2-3 weeks I will post some pictures of the new dsp we are using. The prototype is implemented in my system since a few weeks now but the case isn't ready right now. So I don't want to post a simple wooden board with all the wirings. Attached a picture of the prototype of the case. CNC drilled from one aluminum block worth 10 Millimeter strong walls. The power supply is a 100 Watt ultra low noise analogue version and is placed in a separate case.

Yes, because there are so many prejudices. The way the measurements are taken is written above. The Arta "Over all" measurement is an old one from the time our new dsp wasn't involved. The new one uses IIR and FIR and the response looks much better. But to be honest, I give a shit for flattening the curve Eben the worst speakers can be flattened and they still sound horrible. Phase, Delay, Dynamic for micro informations and the room, that's the main things to me

Both measurements are PN. 15A with 666 is measured exactly at the horn mouth. The other measurement 20-20.000 is measured in 480 cm distance also with PN at my listening spot. It's an left and right measurement, so that the possible phase issues are already shown. But as you can see. At the cutting points are no dips. 160/1650