Time Domain measurements?

[haraldo]

I guess 1st order acoustial filters doesn´t necessarliy mean simple, when I read a whitepaper from Thiel on the CS 2.4 .... it´s an incredibly complex filter to deal with phase and response anomalies in the drivers, and what theoretically should be simple ends up with loads of components ... on the other end of the spectrum, the also phase coherent Meadowlark Kestrel2 has three components in the x-over, I never auditioned the Thiel's but this gotta be very audible

This is what I found when I googled the CS 2.4 crossover

Thiel CS 3.7, pretty hefty

 

[Joachim Gerhard]

At the end of the day it is not possible to make a first order acoustic crossover over a wide frequency range. Thiel ended up with a 5 way in the CS5. You also run into problems with vertical lobing. In the Surveyor I use a second order acoustic Linkwitz Filter. That has the tweeter phase reversed. I ended up with only 6 parts in the crossover. Two parts can be switched out with a knob that you can set between Flat and Fast. Fast Switches out two parts in the crossover and then there are only four parts left. I will show measurements what that switch does. With Accurate from Dr. Brueggemann you can then easily compare if the phase response of the Surveyor is audible or not at a click of a switch.

 

[vavan]

I will show measurements what that switch does

please also more specs of Surveyor

 

[Joachim Gerhard]

I will do that and here are some pictures.

 

[vavan]

iirc you wanted to send surveyor to Amir as soon as it's ready?

 

[Joachim Gerhard]

I have answered that question here before. I have only one pair available for review at the moment and that went somewhere else. We are building other pairs though as fast as we can. I really would like some measurements and comments on this blog.

 

[vavan]

I have answered that question here before

sorry for repeating it then

 

[Joachim Gerhard]

No Problem. Threads are hard to follow sometimes.

 

[Mnyb]

This Surveyor speaker ? does it have a website somewhere I havve found some other site with mr. Gerhard's speaker creations , but not this particular model

 

[Joachim Gerhard]

It is so new that we do not even have professional photos. It will appear as fast as we can on www.joachim-gerhard-collection.com

 

[haraldo]

I have answered that question here before. I have only one pair available for review at the moment and that went somewhere else. We are building other pairs though as fast as we can. I really would like some measurements and comments on this blog.

BEAUTIFUL

 

[haraldo]

At the end of the day it is not possible to make a first order acoustic crossover over a wide frequency range. Thiel ended up with a 5 way in the CS5. You also run into problems with vertical lobing. In the Surveyor I use a second order acoustic Linkwitz Filter. That has the tweeter phase reversed. I ended up with only 6 parts in the crossover. Two parts can be switched out with a knob that you can set between Flat and Fast. Fast Switches out two parts in the crossover and then there are only four parts left. I will show measurements what that switch does. With Accurate from Dr. Brueggemann you can then easily compare if the phase response of the Surveyor is audible or not at a click of a switch.

I am quite surprised that you manage with so few components ... if there is, say a Trinnov in front, is there really very much benefit to going fully active? It is easy to manage phase and frequency response anyways with the Trinnov; there is also some significant cost with going fully active; with your work here, is the passive version getting closer in performance to the fully active one?

 

[Joachim Gerhard]

The most expensive speakers in the world are still passive for good reason. One is that you can play with amps and cables. With the Surveyor I reached a point where I do not know any better active speaker at the same price point. It lacks some adjustability though.

 

[Kravi4ka]

I sure love mine Walnut suits my interior better though the new oak is beautiful as well. The only one I can imagine to like more is rosewood but I will suffer and listen to the ones I have

Active speakers(with the options that for example the D&D 8C have) give us something that we rarely ever heard-the full sound that the speaker is capable of whitout the room interference. Room correction turns mediocre speakers into stunning ones. But that should not be mistaken for a quality speaker.

The 8C did just that - it is an excellent speaker by itself and DSP simply made it sound even better! Yet the Surveyor showed it a few tricks and there was no contest. The Surveyor needs work to find its right place, it needs a good room and good source and a good amplifier to sound it best, the 8C is so much easier - place it close to the wall, dial in the numbers here and there and you are shocked. But there is no mistake which is the true Master...

Guilty of hijacking the thread, apologies.

 

[haraldo]

The most expensive speakers in the world are still passive for good reason. One is that you can play with amps and cables. With the Surveyor I reached a point where I do not know any better active speaker at the same price point. It lacks some adjustability though.

yeah ... I talked to another guy here (Roald Mikkelsen, maybe you know him??) he is the architect behind the speaker above ... stunning speakers, when asking him why he did not make it active, it's for the same reason... there is less playing ground with different types of amp... some like to try different amps, tubes, solid state ... if it's passive it's a done deal ... he also claims for that reason many will really prefer passive, before active. The crossover for those speakers are in a separate box the size of a large flightcase.

If it's active with a digital pre, you can tweak yourself "to death" and forget about what's really the point, just enjoy the music. I do see a lot of guys around here spending all this time playing around with target curves, crossover points, slopes, permanently...... I really don't wanna go there!

I was thinking of going the fully active way with an 8 channel Trinnov, in order to have the possibility to go with 3 channel floorstanders + subs.... but maybe a simple 4 channel Trinnov and passive speakers with subs will do it .... with your large floorstander speakers and subs optimized by Trinnov I don't think there will be so much lagging (and can still make it phase perfect and linear)

(sorry for derailing, and 4 channel Trinnov Amethyst is half price of an 8 channel Trinnov Altitude 32, which will allow for fully active 4 way stereo setup)

 

[Joachim Gerhard]

Here is a distortion measurement we made on the Surveyor. The other picture compares the Purifi driver with a professional driver at 105dB.

 

[vavan]

Here is a distortion measurement we made on the Surveyor

if you used REW to take these measurements any chance of sharing .mdat or am I asking too much I guess?

 

[ctrl]

The other picture compares the Purifi driver with a professional driver at 105dB.

Without question the Purifi-Woofer is one of the best 6-7'' drivers which is currently available.

But the comparison with a chassis that is available for less than half the price and does not have any demodulation rings or similar impedance control devices is a little bit misleading.

In a scenario where the Purifi woofer has to deliver 105dB regularly, it is more likely to be used as a midrange driver >150Hz. There are however comparable chassis (with regard to distortions), which are more inexpensive.

Purifi


BMS 8S219-8

 

[Joachim Gerhard]

Which ones ? There is more then a demodulation ring in the Magnet System of the Purifi.

 

[ctrl]

Which ones ? There is more then a demodulation ring in the Magnet System of the Purifi.

The B&C chassis has (very likely) no impedance control by demodulation rings or copper cap on the pole piece and is therefore at a distinct disadvantage - but costs less than half as much.