New Heathkit AS101 owner - First post.

[Altec Best]

FWIW do you have your sweeps set to 20 Hz - 20Khz ? If your starting you sweeps higher say 500 Hz and up it won't show much bass in your response curves. Like the ones you posted here Alan..

Even if they are tired (416's) you should still see some kind of bass response..More than your seeing.

[alancohen]

I moved the mic down to about 1' off the floor:



and am now getting this:



HF comp circuit and L-pad still installed.

[Altec Best]

Mic should be a little closer IMHO also pointed at the speaker and roughly in the center of the High frequency driver and the woofer.This photo your Mic is pointed at the ceiling. You should be using a Mic stand as well.

Take a look.

http://www.troelsgravesen.dk/measurements.htm

Place mic like this pointing with the stand parallel to the Mic

http://www.bksv.com/doc/BO0102.pdf

You may want to try and remove any reflections as well,like floor bounce.

http://www.synaudcon.com/site/author...-equalization/

And some basic stuff on Wikipedia.

http://en.wikipedia.org/wiki/Loudspeaker_measurement

It's not easy to measure loudspeakers in a room with lots of furniture,etc... due to all the reflections it may produce. Measuring outside isn't always practical but does help quite a bit.

This is the stand I bought for my setup.. Not too expensive.Also bought a 25' cord for the Mic.

http://www.parts-express.com/pe/show...number=242-743

[alancohen]

I don't think so. Google Sansom Go Mic. It's designed like a desktop voice microphone. You speak/sing (whatever) into the front.

Also, sweeps are from 0-20KHz

[cradeldorf]

You have the Mic set to Omni right? Or should I say you've tried both settings? Cartoid and Omni? And I agree with AB it should be exactly 1 meter away from dead center of the speaker, unless your doing off axis measurements.

[Earl K]

I don't think so. Google Sansom Go Mic. It's designed like a desktop voice microphone. You speak/sing (whatever) into the front.

Also, sweeps are from 0-20KHz

A couple of things ;

(i) Your supposedly 6.5R ( ohm ) shunt resistor appears to actually be ( in your pic ) 6800 ohm ( 6.8K ) / or so the pic seems to show .
- This high value will have the effect of giving a lot less midrange attenuation ( as well as changing the load Z the crossover works into , therefore changing how the LC components react ) .



(ii) Your sweeps appear to start at 100hz ( contrary to what you state ) .
- This might be caused by a wrong setting within REW or that mic may just not have much response below 100hz ( not that unusual for a voice mic ).



(iii) ( Since you have the schematic ) I would recommend that you rebuild one crossover completely from scratch, to make sure it's wired correctly .

[Altec Best]

A couple of things ;

(i) Your supposedly 6.5R ( ohm ) shunt resistor appears to actually be ( in your pic ) 6800 ohm ( 6.8K ) / or so the pic seems to show .


(ii) Your sweeps appear to start at 100hz ( contrary to what you state ) .
- This might be caused by a wrong setting within REW or that mic may just not have much response below 100hz ( not that unusual for a voice mic ).

Alan I agree with Earl on this after closer inspection of that resistor it does appear to be 6.8K.. And also reiterate that your sweeps aren't going low enough and the reason for the lack of bass in your response sweeps..

FWIW I use with my laptop.

Fast Track Pro soundcard
Behringer Mic and Mic cable 25'
Holm Impulse software
Jam Stands telescoping boom stand.

IMO Holm Impulse is much easier to use for beginners..

[cradeldorf]

That ought to make it sound better.

[alancohen]

Alan I agree with Earl on this after closer inspection of that resistor it does appear to be 6.8K.. And also reiterate that your sweeps aren't going low enough and the reason for the lack of bass in your response sweeps..

Oh crap, it is an 6.8K! It must have been misplaced on the display rack cuz it came right after the 5 ohm and before the 8s. I never looked. I still didn't see after reading both your posts. I still read the 6.8K as 6.8 ohms. Man, I suck. I guess I have a trip back to the electronics store tomorrow! Good catch guys.

The bad news is my new 802-8Gs should be here tomorrow too. Do I install them too while the back is off or exercise patience and wait for the new mic to arrive?

I think I'll take Earls suggestion and rebuild the XOs without the L-pads. After all, what are the chances that I'll need to mitigate the highs?

And FWIW, the Samson Go Mic supposedly goes from 20Hz to 18K and REW is definitely set to start at zero Hz.

[cradeldorf]

You bought new 802's or are you talking about the ones AB offered to loan you?