Changing X-over Frequency or Speakers Trim Level

Posted by: berbautista

Changing X-over Frequency or Speakers Trim Level - 10/25/06 09:20 AM


Hello to all of you. This is my first posting. I installed last week an EP 600 and did a calibration together with my in-ceiling surround sound speakers for the first time. I used
a RS SPL meter and a tripod, both of them borrowed from relatives some 30 miles away.

I set the receiver X-over at 80 Hz and the sub trim level at
-5 dB. All speakers set at 75 dB but the sub at 85 dB.

Now, after reading some posts, I would like to experiment changing the crossover from 80 to 60Hz. If I change it to 60Hz, will I repeat the whole caliration again? Same question with changing the trim level from -5dB to -3dB.

BTW, I do not have the tripod and the SPL meter anymore as I have returned it after my first calibration last week. That's why I posed this question.

Thank you all for your advice.

Bernie
Posted by: michael_d

Re: Changing X-over Frequency or Speakers Trim Level - 10/25/06 10:07 AM

Whether you will have to, or should re-calibrate depends on your speakers. Itís hard to comment or suggest much without knowing that, can you include that info?

My most recent calibration episode using the Avia test DVD over the last few days proved to me that changing X-overs does change LFE levels to the speaker. When messing with it, I changed the mains from 80 to 60 and nothing much changed. But when I changed the other speakers from 80 to 100, the LFE on those channels went up about 10 dbís. This helped out quite a bit. It helped balance the LFE throughout the room and got rid of the extra high peaks in volume during some actions scenes. Not that I donít like to hear my 600 rattle doors and windows, but it is pretty distracting when sound levels range from 60 to 100 dbís.

One thing you may want to do is lower your split. Calibrating to sub to be 10 db higher seams excessive to me. I have mine calibrated to as close to the speaker levels as I could get it with the sub set to -6 on the AVR. Then if I get the itch to have more LFE, I can just go to the AVR settings and raise it some. But now I know that Ė 6 is the same as the speakers. We watched the LOTR, Return of the King extended version last night and I never felt the urge to bump up the sub.
Posted by: jakeman

Re: Changing X-over Frequency or Speakers Trim Level - 10/25/06 10:35 AM

I agree with Mdrew. +10db is very hot and will overwhelm the speakers (and your neighbours) . I run my 3subs combined flat with the speakers at 75db and the sound is well balanced. Occasionally I nudge up the subwoofer level a notch or two at the processor depending on how the soundtrack was transfered. What speakers are you using and what are their FR specs? Better results can sometimes be obtained by setting the crossover 1/2 octave higher than that bottom FR spec for speakers that extend to 60hz or less. Also remember to add 3-5ft to the subwoofer delay to account for the DSP in the 600 and its vented design.
Posted by: berbautista

Re: Changing X-over Frequency or Speakers Trim Le - 10/25/06 11:26 AM

Thanks to mdrew and jakeman. Your inputs point me to the right direction I should pursue. It's very helpful, believe me.

Now, to give you some more details:

All 5 in-ceiling speakers are made by Speakercraft. FR at +/-2dB is 38Hz-20KHz. I used the test tones from my Yamaha RX-V1500 to calibrate the speakers and EP 600. I fixed the receiver's master volume control knob at zero (0 dB) as the reference point, and adjusted the speakers trim level from +1.0 to +3.5 to get me a reading of 75 dB on the SPL meter. For the sub, it registered -10 dB on the trim level and 78 dB on the SPL meter (The sub volume is set at the 7:00 o'clock position). At these settings, I hear no explosions, no poundings coming from the hoofs of the giant elephants in the LOTR's ROTK. Out of luck, I managed to get some good sounds when I adjusted the sub's trim from -10 to -5dB (remember, this is my first time to do this calibrations).

My speakers are set to "small" and receiver crossover at 80 Hz. EP 600 crossover is "bypassed". Sub volume at 7:00 o'clock position.
Posted by: Nachosgrande

Re: Changing X-over Frequency or Speakers Trim Le - 10/25/06 11:38 AM

A few things to consider -

Have you adjusted the manual gain know on the back of the sub?

If you are using one of the well known calibration disc - I believe the .1 subwoofer recording levels were off. Can anyone confirm that?
Posted by: jakeman

Re: Changing X-over Frequency or Speakers Trim Le - 10/25/06 11:49 AM

I suggest you get a dvd calibration disc like Avia or Discwasher (which is cheap and easy to use) and recalibrate. That way the levels are matched from the player to the speakers/sub. Something is off somewhere or you need work on sub placement.

Also suggest you set the crossover at 60 with those speakers. Then experiment up or down 10hz at the crossover to see what sounds better and has less flucuation on the RS metre. Also flip the phase switch between 0 and 180 to see where its louder. And test the trim on the 600 from flat to half to see which setting has less needle flucuation on the RS metre. Finally a small movement in where the sub is located may make a big difference.
Posted by: michael_d

Re: Changing X-over Frequency or Speakers Trim Le - 10/25/06 05:46 PM

Subís volume control knob is at 7? Thatís just barely off minimum if I remember correctly. You might try and lower the receiverís trim so you can get the subís volume control knob up a bit. Whatís your room dimensions? Mineís 12 X 16 with 8.5í ceilings. The sub is about 9 oíclock (maybe 25%) with the avr trim at Ė 5 and itís quite loud when it wants to be.

What is the trim on the subís amp?? Run that flat if it isnít already.
Posted by: berbautista

Re: Changing X-over Frequency or Speakers Trim Le - 10/26/06 12:50 AM

Guys, I am sorry for the late reply. I will try all your suggestions tomorrow and see how it goes. Just arrived home.
Picked up the meter and tripod on my way home.

Anyway, my room is 28 x 23 x 9'. Sub's trim is set at FLAT. At 7:30, I got a W-3: Level Error (Subwoofer too loud). When I adjusted sub's volume contol knob down to 7:00, and run the receiver's AUTO SETUP, I obtained a sub level of -10dB. The other 5 speaker's level range from +7.5 to +10dB. Please see tabulation below:

SUB @ 7:30/SUB @ 7:00/RECEIVER TEST TONES & SPL

Front L/ +1.0dB/ +10.0dB/ +3.5 @ 75dB SPL
Center/ 0.0/ +8.5/ +2.5 @ 75dB SPL
Front R/ +0.5/ +9.0/ +3.5 @ 75dB SPL
Surr L/ -1.0/ +7.5/ +1.0 @ 75dB SPL
Surr R/ -0.5/ +8.0/ +2.5 @ 75dB SPL
Subwfr/ (none)/ -10.0/ -5.0 @ 85dB SPL
Warning W-3: Level Error
Subwfr too loud @ 7:30 knob position
Posted by: jakeman

Re: Changing X-over Frequency or Speakers Trim Le - 10/26/06 07:55 AM

As has been mentioned in several posts do not rely on the receiver's auto-calibration or room correction to adjust speakers and subs. Always better to manually adjust using calibration disc and RS SPL metre.
Posted by: berbautista

Re: Changing X-over Frequency or Speakers Trim Le - 10/26/06 09:40 AM

John. I will buy the disc you mentioned. Might take a while. About to leave for work now. California time.

Thank you all.