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In the Forum: Horn-Loaded Speakers
In the Thread: Eventually - a reasonable midbass horn from GOTO
Post Subject: More goto...Posted by Jeffrey Jackson on: 2/14/2008
Hello again Romy and cats...
sorry so slow in replying to this thread... the recent posts generated an automatic email reminder... :^)
so a few things... one, there is a pair of Goto 370 on eBay and pictures of insides... the newer ones are made the same, but it seems that the execution has gotten a better/cleaner compared to these.. my diaphragms look smoother and the glue seems to be neater... I may be able to dig the pictures out of an old email if needed... I lost a lot in a drive crash a few months back... my fault for not regularly backing up...
field coils.. well, though I do also hear that you improve some areas and worsen others when varying voltage and therefore Qes, field coils and permanent magnets aren't different with regards to how they react to frequency... you certainly may find a permanent magnet driver that you like across the full band of the horn, but it isn't really due to the permanent magnet... as with all drivers, the magnet is just one of many variables.. I think the horn should be built to compliment the driver, whether field coil or not, just like any driver.. and maybe view the field coil as a bonus that will allow fine tuning once in place..
I do hear some things about field coils that I don't hear in permanent magnets.. but it is hard to say that it is directly due to field coils... I think, in general, they do sound a little smoother.. less grain... but this isn't a proclamation of "field coils are best" because I haven't really found that to always be the case... especially at low frequencies.. too many other things are more important...
so my goto system... well, the basshorns are slowly being built... they won't use goto, though... (at least at first... but I may try an extension and my 505 drivers).. straight six foot 60 Hz horns... mouth about fourteen square feet... I am stil planning for physical time alignment to try to avoid digitizing my analog at this time.. I may change back at a later date... but you misread my wife... she doesn't mind large, just doesn't like unfinished R&D style horns... so I have to actually finish them, something I normally would only do for customers...
and why did I choose goto you asked? well, from listening.. a friend loaned me his goto horn and midrange compression driver for about six months two years ago.. at the time in one of my systems I was using a digital eq/crossover/delay and could quickly try many horns with this unit.. (it is amazing how fast you can dial things in when the controls are on a laptop and you are in the chair while turning virtual knobs!).. I did not eq it, but I did play with crossovers and set proper delay.. and the potential I heard in that driver I just haven't forgotten... the transient detail on solo piano I had never heard before... I sat in awe when listening to solo Monk... and this driver/horn combo also seemed to fight off congestion at high volumes on complex music better than any I had heard.... this is something that is very important to me personally... so when I had the chance, I decided to try the goto drivers.. oh, and their breakup seems different.. perhaps due to the mylar surround... it doesn't break up like JBL/Altec... not sure why...
another big selling point to me was the 505 being a low resonance compression driver.. there just aren't many drivers with a resonance in the 80 to 100 Hz range like this driver... I have just begun my playing, but am already quite taken by it... this driver and its 48", 150 Hz horn will likely be the last thing I change.. it sounds very good...
I am beginning to get slightly dissatisfied with the 370 on the 600 horn.. and I think it is the horn.. I think I must be spoiled by the leCleac'h and conical flare horns and their ability to radiate a more even power response into the room.. the result, to my ears, is a more natural and "open" sound.. maybe less focus, but it is hard to say for certain... luckily, I can easily turn horns of this frequency on my lathe..
so.. did I miss anything? oh, yes, you asked about line level crossovers.. and, yes, I have done this many times... the last was using 80% nickel inductors and directly heated triodes WE 104d and mesh 50.. I also used 80% nickel autoformers for level control... first order, of course...
gotta run... please keep pursuing horns.. we need more people to listen and learn.. your knowledge of horns certainly has grown the last few years.. keep up the good work!
Peace,
Me
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