ygoh wrote:

1.) What's that formula to calculate the back chamber volume given a throat reactance? 2.) Would it be a bigger back chamber with higher reactance at the throat?   or vice versa?

 You do not need any formulas. Use the guideless form this post: Practical Guide for Back Chambers Tuning.

Kcct82 wrote:

On to other things... now that we've been using the GOTO SG505 for a while, the verdict is that it does not sound good below 290hz.

As I understand you use the GOTO SG505 in 150Hz horn and report that it does not sound good below 290Hz. If so then it would be interesting to know what was wrong specifically with sound.

There are only 2 reasons why it does not sound good: problem with horn and problem with driver. You might test them independently buy I do not thing that it is the drivers but rather wrong driver for a wrong horn as I feel that got is kind of damn about it. 

What high-pass filter you use? Although the GOTO’s Ming said that GOTO recommend using first order crossovers but I presume that they begin to do it after reading and learning from this site as few years back.  Formerly GOTO insisted to use 4th order only and it frankly might be for good reasons – theirs drivers are too generic and nonspecific. My perception of proximity of crossover point to the horns’ rates based upon relatively fast opening horns. GOTO horns open very slow and the slow-opening horn might need 1-2 octaves at the bottom in order do not have the “boom”. Here is where the GOTO demands for 4th order came from.  In the following post:

http://www.goodsoundclub.com/GetPost.aspx?PostID=8750

Ming Su, as an official GOTO rep, put GOTO drivers into 1-st order camp. It is very god in my view as the 1-st order is the way how it must  be done but the system shell be designed and thought out initially to be able to work within 1-st order. GOTO were not thinking in context of first order to begin with, the park of their drivers, their horns are a clear indication that GOTO allays were minded about high-order crossovering system. So, what Ming Su said sound sexy for the ears of cogent horn aficionados but it might be not supported by the GOTO products. I do not think that what Ming had any sinister intend. To state that GOTO is “1-order comply” system sounds good (particularly fro the reads of this site), it is might be even something that GOTO people begin to believe in themselves. However, I think that looking in the way in which they sliced the audio range among the drivers and the characteristic of the drivers themselves I presume that they had very high order in their minds.

So, if GOTO SG505 in 150Hz horn does not sound well 290Hz then I would sharpen the filter and to see if it get better. Most likely the slow opening of the GOTO horn with it’s long pipe get too much saturated with extensive for the given profile LF.  It is highly possible that the legend of “slow opening horns has better bass” might derived expectedly from this misperception: people might recognize the choking sound of the slow opening horns as “more bass” from horns.

If you more describe in your own words the specifics of the sound below 290Hz then it would help identify if my assumption is “hot” or “cold”.

To use a Class D amp on those SG-146LD GOTO drivers? Is it what GOTO proposes? Hm, I do not know, the more I learn about them the more question I their sanity. The SG-146LD does not adjustable resonance frequency. It means that in whatever horn it will be used it will have no option to dial the resonance frequency to the given horn reactance. The only one minor way to do so for people on the filed would be to tune the SG-146LD loading to an amp. However, the Class D amps have no sensible loading. They are animals what will drive anything and will push senseless through anything….

About those shaking devises – I truly hate them. I mean I did not hear them, I heard a few similar but I truly hated the concept that I feel is fundamentally faulty. All those “shaking” anticipations are pure inventions of bad marketing and former experiences of bad audio. There are no shaking events in live sound. Did you even have any shaking experiences or body pressure during live music? I do not mean the pop/rock/jazz crap but I mean the live play of musical instilments when sound is created by natural vibration of subject in air. You can listen a 35”organ and you will never feel any body vibration. Never!

In audio the morons build up the atmosphere pressure before then build up tonal pressure and to insult the injuries they now stick in the brains of already fucked audiophiles a dildo of shaking sensation. Wonderful! Let wait until it will make the TAS recommended component of the year…

I think there is nothing that I need to comment – I have done it before many times:

http://twogoodears.blogspot.com/2011/03/more-elodis-tge-gotorama-pixes-plus.html

For sure the owner of this system would get much meter result by NOT using the horrible Goto “slow” horns but I am afraid it would violate the “cult” sensations.  Anyhow, this is the only attempt I seen where the Goto system owner demonstrates some very rudimental sense. Sure he has room to go  but for any typical superficial Goto user this guy is in advance stage.

tuyen wrote:

This is my current 4-way GOTO setup. I know it is in no way optimal but I am interested to find ways I can improve it's layout. GOTO SG-38WN woofer in 360L onken cabinet GOTO SG-505TT mid-low driver with Azurahorn AH-160 horn (160hz le'clech profile) GOTO SG-370 mid-high driver with Azurahorn AH-550 horn (550hz le'clech profile) GOTO SG-16TT high driver with GOTO 3000? horn Using a Pioneer D-23 active electronic crossover. Crossover points are 250hz / 1.25khz / 5khz.  All with 6db slopes. I attempted some sort of diaphragm alignment for the horn channels. But not sure how to do the bass properly.

2) You use external active crossover. It means you multi-amp. I do not see any amplification in the playback; in fact I do not see any wires. Is it operational installation or you juts test different configurations and layout? Anyhow, if you multi-amp, and particularly with first order then after you find the right final crossover points then get rid of the D-23 and go for line-level passive filtration. It will give you tremendous advancement.

3) Since you multi-amp you might reconsider to use first order on your perhaps MF and most certainly tweeter. Unless you use SETs with sub 1W then it might be dangers for your Goto drivers. The HF Gotos drivers have no power handling and there are many Goto users out there who burned the Goto’s voice coils.  So, use some logic to protect your tweeter as they are very vulnerable with first order.

4) It would be very interesting to know what amplification you use for your channels.

5) Your 160Hz La-profile horn is a bit controversial in my view. I do applaud your idea to bolt to run it from that 1.5” through, or whatever it is but there is a twist in this notion.  You are in AU and you apparently was presold by your local Azurahorn guy to go for La-profile. The La-profile horns are what he does but the use of the La-profile for base horn is not something that I endorse. I did speaks about it before. The La-profile (the people who can spell call it le'clech profile) are HF optimized horns but for a base horn (base horn is a horn upon which the rest of your system is sitting) is not HF devise. La-profile drops at the bottom very fast and La-profile consume extras few inches of your highs for negative opening that is absolutely irrelevant at the frequencies where your Midbass horn operates. So, you have approximately 36-40” window for your base horn, you can’t go more as you need to have MF at your ear level. You stick an upper-bass horn in the base location – which is very fine but you wasted probably 15% of the space for non-working negative opening of you La-profile. If you do for the same diameter Tratrix then you will have 100-120Hz horn and it were Exponential then it would be probably 80Hz horn. The Exponential would be a foot longer however. If I have your horns then I would probably cut the bottom 3” and top 3” from your upperbass horn, or perhaps 2” of the peripheral.

6) Since you use Goto driver to drive your upperbass horn then you need to play the Fs games with this channels. Remember Goto people (manufactures, dealers, etc) are clueless what they do and you would never see any Goto people who match resonance frequency of their driver with their horns. You need to do it for upperbass even this your upperbass is compromised by La-profile.

7) The 5khz crossover point in the Tweeter? Why is it so? OK you would like to kill your tweeter with 5khz and first order - this is given and in a week it will be dead. Still purely Sonically – you have relatively HF- able MF driver in very fast opening horn – why you do not drive it all the way up? Are you saying the your GOTO SG-370 in La-horn rolls off at 5kHz or sound so bad over  5kHz . I do not think that you are correct and I would like your MF to shoot at least one octave more.

8) Drop a thick capper in front of your speakers – the glossy floor is not what you need to have in there.

9) On the left there is something that looks as it is a door. Is it a door into your listening room? If so then move your both speakers one meter forward and the left speaker one meter on the left, right next to the wall. You will have wider acoustic bias in the room and still will be able to enter the room from behind left speaker.

10) Did you consider change of the room? I mean is it possible to knock the left wall and get more 5-6 feet of the room width? If you have extra 6 feet of the room then you might try the long-wall configuration.
I do not have time to write more now but I think what I have expressed would give you an idea of the initials directions I would be looking.

I interacted at AU site where Tuyen was trying to build his new installation:

http://killerdac.com/forum/index.php?topic=60.0

Eventually I withdrew myself from that community as it was very much beneath my level.  I do not have anything against Tuyen or other people in there but the general level of discourse that is going on in there is too primitive to waste my time anymore. It partially a general attitude that I have lately: I do feel that audio people out there have audio interests that stimulate me very little. In fact I wrote a large post about it, probably I will post sometimes. The situation with Tuyen’s installation is very similar with what I feel about another multichannel- horn installation:

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=16294

All those guys do right things and express nature interest in improving own playback but they are light miles away from where real sound begin. They are not driven own sonic demands but they rather preoccupied with rendering this or that solution. This is endless travel to absolute nowhere and I feel incredibly bored with those people , the people who do  not invest own personality and own more or less civilized musical demands into audio accomplishments. As a culmination of the Tuyen’s thread was showing up at that forum that retard from Brasil Angelo – the brainless idiot and scam – the materialization the worse in internet Hi-Fi.

What was very interesting in the Tuyen’s thread is the face of a typical Goto user – a person who is so obsessed with his Goto symptom that he is not able to relate to reality.  It feels like foe those people there is no Sound but there is Goto Sound as some kind cult expression. The fun part is that sect attitude is not supported by advanced users but rather by the guys who are in Goto trade.  The most emblematic was my conversation with Goto US rep who in response to my concerns about Goto sound kept telling me that “Goto is not for everyone but only for those who can afford it”. How more idiotic could it be?!

The said reality is that if to look at the implementation of multichannel installations out there and group the topological advancement by the tendencies of owners to use different drivers then Goto users would be at the very bottom of the taxonomy. The Goto users are too stupid to get it but it what it is. Funny but what Tuyen is trying to do with his playback is very much anti-Goto installation, unfortunately he a bit ruined by another cult – the La-horns but this is a whole another subject. It is another subject but it is still the continuation of the very same subject – those people do not build Sound of own mind but they chew each other’s shit without realization that audio is all about.

I truly miss collaboration with a community of audio users that offer simulative ideas and who use audio and a tool of advancement of accomplishments instead of a crutch of mediocrity. Got users feel that Goto are superior driver but the mediocrity of audio thinking from Goto users burst like a volcano. Is it cause or a reason? I do not know the answer. Friedrich Nietzsche when he stop to write by hand and begin to use a typewriter noted that his thinking and his way of expression of own thoughts begin to change and become less fluent. His quote that I use in my signature line: “Our writing equipment takes part in the forming of our thoughts" come from him in response to those events. I wonder: is anything in Sound Goto drivers that make a person to become stupid in the realm of audio-perception? This is the question with very much pending answer and I see a lot of evidences that support this proposition.

As you can predict what I am going to say, those horns are the problem, not the GOTO driver....  Why will anyone buy GOTO driver and then not follow GOTO recommendation to use GOTO horn???  I don't think anyone buy a Lamborghini or Ferrari sport car and decide to use regular gas for unknown reason or just want to try something new and different.  When the car doesnot perform on the road, it must be the car is the problem, not the driver and not the fuel that you pump into the car just because you don't want to follow the manufacture's recommendation/requirement.

You got my point. 

MINGSU wrote:

you don't want to follow the manufacture's recommendation/requirement.

MINGSU wrote:

As you can predict what I am going to say, those horns are the problem, not the GOTO driver....  Why will anyone buy GOTO driver and then not follow GOTO recommendation to use GOTO horn???  I don't think anyone buy a Lamborghini or Ferrari sport car and decide to use regular gas for unknown reason or just want to try something new and different.  When the car doesnot perform on the road, it must be the car is the problem, not the driver and not the fuel that you pump into the car just because you don't want to follow the manufacture's recommendation/requirement. You got my point.

In audio the situation is far more complex then with cars. In audio a brand that a person use, would it be a cartridge, driver, amplifier, tube, cable, DAC or anything ales, has absolutely no deterministic value to the final result a person get. In fact the only deterministic factor I know in audio is the reference points of playback owner as anything in audio is subordinate to his will. Those reference points is exactly what I question in many Goto users and from what I see instead of demanding and demonstration of own reference points then embrace some kind of bizarre generic Goto idiocy, presuming that the Goto drivers act as a shield that protect them from common sense and a needs to have a rudimental understanding of what they do.

BTW, your reference to Lamborghini, Ferrari and the similar “moves” is very expected. I think instead of taking about Lamborghinis and Ferraris the Goto user might educate themselves a bit. Otherwise they will remind just the people who glue Lamborghinis emblems to Volkswagen and then push the Volkswagens from the hill by hands.

MINGSU wrote:

As you pointed out, there is no simple answer but manufacture recommendation should be the 1st to try.

MINGSU wrote:

Have you use GOTO dirver before?  Have you try it with the "GOTO" recommendation?  Have you listen to GOTO in your own system?  If not, I suggest that you do it 1st and then draw your own opinons then.  GOTO never said don't worry about alignment.  That is part of the setup and fine adjustment of a multi-horn system.  It depends on the room and other factors.  However, if you do not start with the suggested crossover point and type of horn to use, you will have hard time to do alignment.  Again my favor car example - by talking about F1 race or watching F1 race will not make you a F1 race driver...... Of course, there are many other driver and horn that people can enjoy and play... there are ALE, GIP, TAD and many other vintage driver and horn. I happen to be a supporter of GW Bush.  I doubt that he will teach in MIT but why will one ever want him to teach at MIT at 1st place???  Is it GW's fault or whoever has the idea's fault??  I rest my case.................................

MINGSU wrote:

Here is an example on how to use GOTO 505TT driver.  Use the GOTO S150 horn and crossover at 200Hz to 1kHz.  If you like to use other type of horn and crossover point, you are on your own.  Maybe good or maybe not but that is your choice.  Yes.  You are correct, every room will be different but the basic setup and crossover of the GOTO SG505TT + GOTO S150 horn will be the same.  For GOTO SG370, use GOTO S600 horn and crossover from 1kHz to 5kHz. For GOTO SG160, use built0in GOTO S3000 horn and crossover from 5kHz and up. Use 1st order with active crossover.  Use 2nd order with passive crossover.