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In the Forum: Horn-Loaded Speakers
In the Thread: Eventually - a reasonable midbass horn from GOTO

Post Subject: Another more or less reasonable attempt using Goto.Posted by Romy the Cat on: 4/7/2011

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.

Well, tuyen, this already something. Your former setup with a pile of Gotos sitting atop of the Onken boxes was no worth to mention. I am glad that you eventually came to the Macondo configuration, which is inevitable if a person is not audio-deaf.

You asking to point out weak elements of your setups. Here it comes, without out any specific order of thier severity.

1) You have LF source between the MF sources – this is contradiction of the Macondo Axioms. I understand that you care less about my Macondo Axioms, wait until you live with this setup for a while and it will come to you. What you need to do now is to disconcert your Onken, then bring any bookshelf monitors speakers in the room and connect juts woofer (you can take out the tweeter). Place the monitors in the location of Onkens and EQ them to get any more or less reasonable sound, you do not need to have good sound at this point – juts balance enough sound will be fine. After you get comfortable then move your monitors in the position outside of your Midbass channels. Pay attention what happen with imagine and overall presentation. Make your own conclusions further.

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.

The caT

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