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In the Forum: Horn-Loaded Speakers
In the Thread: Eventually - a reasonable midbass horn from GOTO
Post Subject: RTAPosted by Jorge on: 6/24/2011
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Do get an RTA,  it is amazing how different the frecuencies are from what we imagine, 50 hz is very low!  150 hz is a vital freq, and a lot of female voices have a very nice fullness at 150 hz.  It is hard to tell without measuring what is happening in your system and in your room.
You have to learn the way your room interacts too,  ie, my room has a resonance at 50 hz and a small suckout at 100 hz on one side.  I tried to fix that electronically,  but all musicality was lost,  I had to RTA everything and adjust volumes as good as possible with still some spikes and deeps but very musical.  This is where multiamping helps a lot.  But these adjsutements have to be guided by RTA readings.
I have even found in a friends system that one of his woofers was wired incorrectly from the factory,  so a double woofer box on one side,  was having terrible readings untill we inverted the wires on one unit,  then all was fine,  and the sound was terrific.
Now it is important to know what your system is putting out with measuring,  but the adjstements that really count, can only be done by ear,  no RTA is sharp enough or has the taste to tune your system as you like it,  and this tuning is what music is all about.  You can have two systems that measure "perfectly"  and one will sound like crap while the other will be heaven.

IMHO the thing about GOTO is that we keep judging it as it was a finished product, as it was a Ferrari or a Lamborgini,  when the truth is,  they only sell the wheels,  or the engine, (no pun intended).  When you go out and buy a pair of speakers, say those horrible box speakers, the designer has already made all the adjustments,  with an RTA, and a handfull of wirewound resistors (jijiji) and gives us a finished product of whatever quality, and that is what you get.  If you want to readjust bass,  push them closer to the wall!  But it is one big package,  GOTO can only serve the DIY market,  with all the different specimens of diyers included.  So they give some starting guidelines,  point the horn forward to the listener... If you dont get enough volume at 200 hz get a second driver.

I have at the moment installed a pair of JBL 2490 drivers on my 120 hz Tactrix horns,  taking out a 10" cone driver and adding an extension.  I get very good flat response from a little under 200 hz up to 1.5 khz and then it gets spiky.  Compared to the cone driver inside the horn,  the compression driver down to 200 hz is wonderful,  it is not a huge difference but clarity, dinamics and integration are better,  of course the cone driver goes down to 100 hz and that makes a very big difference in bass and fullness,  mostly when my channel right under it cannot go any higher than 120 hz,  so I have a big hole,  but it is fine a the moment, I want to learn what the 2490 can do and cannot do,  in order to help it out with the other channels.  I am now working on a mid bass horn down to 50 hz (40 hz hopefully) and may be doing a smaller horn for the 2490 and bringing the 10" drivers back on duty,  but for the time being, I will get to know the 2490s perfectly.

PS: Yes I did push back all the other horns as far as the new extension will go in order to time align everything!

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