Altec A7 and Altec 1650 EQ

[Kinnick]

Sorry for long post, I just could not help it.

I have not posted here lately or very often but i wanted to let you know about my experience last night.
System:
Speakers:
Altec Lansing A7: Homebrew 828, 515-8G, N8500, 902-8B on 511b horn.
Source:
Don't Laugh: Bang and Olufsen 5000 System.

Now for the fun stuff:
I purchased a pair of 1650 Eqs a couple of years ago and never did anything with them. I finally decieded last night to put them in my system. First off, one works the other does not. So, keep that in mind, so no balanced stereo yet.
.
How i set up my one channel (I have no measurement equipment):
I set all filters to Max Cut,then Zero Cut at 31.5HZ and 16kHz. I Did not notice much effect. Then alternating from Low to High Frequency Sliders adusting utill i finished up in the middle of the range. I adjusted until max or it sounded equal in output per it relitive frequency range. I did this as fast as i could with out looking. The eq was on top of the speaker, so i was kneeling down with ear very close to speaker but mid way between the drivers.
Then once done with that, and only that one speaker active i ran back to my listing position.
Oh wait, source sound was Chick Corea's Acousic Band CD, and i did max the N8500 adjustment knob.

I was absolutly surprised with the result:
Acoustic Bass or Low Frequency, what ever you want to call it. It was there and i could really hear it all. Before i always thought i was not getting any bass out of my speakers. The simple truth is that it was there, it was just so much softer than the rest of the spectrum. The only word i can think of that describes what i heard was "real".

High Frequency was they same result. again I thought my speakers were really rolled off on top. That is not the truth at all, it is there, every thing was so much louder that it did not register with my brain.

Horn honk was Gone, Gone, Freakin Gone, Baby Butt Smoooooooth. My old B&O sounded like a tube amp with tight fairly extended bass and highs (ok, i am getting a little carried way now, but is was amazing).

Ok, the actual limits of the frequency range.
After several tracks of total amazement, i decieded to experiment a little. using the High and Low Pass sliders.
High Pass:
*** i slide the High Pass up the range I did notice notice a little effect just as i reached 40hz, then obvious around 80Hz, i then slide it to off fast. The sliding to off fast resulted in sure disbelief. It was like getting hit by the BASS TRUCK!!! I did this over and over again, Around 80 Hz i really noticed it, slide to off, hit by a the bass truck. I can not explain it. I found with extended listing that the range between 160 down to 50 Hz, is really hard to come up with extact setting, minor adjust seem to be required in this area even from track to track, but it could be because i never heard this spectrum before and now extremely sensitive to the new experience.
Low Pass:
This is really even more strange. I move the 16k Hz slider up and down. I don't hear much effect with out major adjustment of 3db or more. If i move the 12.5k slider i notice it with very little movement. But as soon as i started engaging the low pass cut it was very obvious.

So the setting of my sliders(hz=cut db (best guess), and high and low pass sliders are set to off:
31.5=0
40=0
50=0
63=1
80=1.5
100=2.0
125=2.5
160=3.0
200=3.0
250=3
315=3
300=4
400=4
500=4
630=4
800=4.5
1000=6
1250=6
1600=6
2000=9 (this setting really kills any honking)
2500=7.5 (this setting really kills any honking)
3150=6
4000=6
5000=6
6300=6
8000=6
10000=6
12500=5
16000=0

I don't know if this helps any one. But i believe the effect is awesome. I have to find some one to fix my other eq soon.

Kinnick (I believe i have had other user names that i have posted under: Yoyoma, and maybe ReallyBigWoofers)

[Kinnick]

Over lunch (i work from home) i went down stairs and listened again. Even though i have only one channel eq'd, the result is still amazing. I can finally follow the base lines and i don't notice any horn ring at all. Hopefully i can find some one who can fix my other 1650 soon.

Kinnick

[ZilchLab]

Yes, they're decidedly "Forward," and the excessive midrange masks both the lows and highs. You've discovered that they can be tamed, and your compensation curve in that range looks like a fair approximation of what is required.

To get it more accurate, I'd advise you to acquire some measurement gear. Even the $50 Radio Shack SPL meter will get you closer used with a tone generator, available online as downloadable files, or commercially on CD. Also find the calibration curve for that meter online; it's not accurate in the HF, and you'll have to do some corrections.

For ~$300, the Behringer DEQ2496 UltraCurve Pro is both stand-alone 1/6 octave RTA and 31-band digital equalizer. Push the AutoEQ button, and it'll generate whatever final response curve you desire. Transcribe what it does to your graphics, and compare the sonic quality of the results. Negotiate for a free mic and cables with purchase at your local Guitar Center or similar pro audio outlet....

<font color="#FFFFFF" size="1">[ January 25, 2008 08:16 PM: Message edited by: ZilchLab ]</font>

[Kinnick]

Thanks for the reply, after i get my other 1650 repaired, i will give it a try. So far, I am having a blast playing around.

Kinnick