Low volume with preouts

CEC

Standard Member
Hi there,

I just got a [-]new[/-]old receiver, Yamaha Rx-V765. I found that its preouts have very low output. For example, I need to give my sub a full turn on its gain control in order to get some bass. At that setting I would expect full earthquake + broken windows but I only get very gentle bass suitable for 11pm...

The sub has no problem at all. I swapped cables/connectors and it is the same.
So I hooked up a pair of active speakers to the Front preouts and again, for a reasonable volume I need to use the full gain as before.

Tried all the preouts (there are 8 of them), all seems to have low output.

To compare, I put my active speakers (gain set to 10 o'clock) to the line-out of the receiver and it was outputting good volume with receiver volume -20dB.

Put the active speakers (gain set to 10 o'clock) back to front pre-out, I can only get to a reasonable volume by setting my receiver's volume to +10dB :eek:

I would believe the receiver is faulty, considering the fact its pre-outs were hardly pre-amp'd?? In fact they are probably down-amp'd?? The preouts are rated 1V/1.2kOhm and line-outs are rated 200mV/1.2kOhm.

Before start shouting to my reseller, do you mind sharing some ideas :lease:

Thanks a lot!
 

PSM1

Distinguished Member
Have you run the auto set up? Did you hear the sub during the auto setup? How loud was it?
If so what are the individual speaker levels set too within the amp? What is the sub set too?
The outputs from the preouts will be governed by the main volume on the amp but there will be a setting within the amp for leveling of the various preouts. If you do not normally have anything conencted to the other preouts for the other speakers then I would not expect them to be set up with a suitable level which could explain your low level sound with your active speakers on the front preouts. The line out will be a higher, fixed level output which is why that will sound louder at the moment.
 

CEC

Standard Member
I haven't ran the auto set-up. However I tried test tones and I could hear the sub only when its gain was set to about 2 o'clock.

The receiver was factory reset by me when I noticed the low volume output so all the speaker levels are at the default (0dB). I could balance the overall outputs by setting the sub level on the receiver to be +10dB (max), not sure if the auto setup will do the same. I will give it a try tonight.

I didn't see any setting for turning the preout specifically, there is only a "speaker output level" setting for each channel.

I think the setting for speaker ouput levels are for both speaker out and pre-outs? Say if I change the Front Speaker level to be +3dB I would expect both the speaker out and preout volume to be increased by +3dB?

Thanks very much!
 

dante01

Distinguished Member
I think the problem lays with you and you preference for overboard bass than with the amp or your subwoofer? The amp will automatically equalise the bass output in relation to your other speakers and your listening position. You should use the auto calibration in order to set the sub and speakers up correctly. If done correctly, the sub pre out is calibrated so that its output is levelled in accordance with the response obtained during auto calibration.

If you can't see a level setting for the sub then you've not set the amp up correctly and you've not specified in the speaker configurations that a sub is connected and to be used. The sub has its own setting for levels and is not effected by the settings for the other speakers. Again, these levels should initially be determined by the auto calibration process or via the use of a SPL meter. You cannot accurately determine the correct levels to use by ear.
 
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CEC

Standard Member
Unfortunately (fortunately) I am not a bass lover at all! I would hope it was my problem but the more I test I more I start to question myself.

It is not just about the bass as I found out other preout have similar issues *_* I don't have perfect ears but I am definitely not deaf... Merely getting something audible by setting the gain to max sounds crazy for me....

Nevertheless, I will definitely use auto calib to test tonight :p
 

CEC

Standard Member
If you can't see a level setting for the sub then you've not set the amp up correctly and you've not specified in the speaker configurations that a sub is connected and to be used. The sub has its own setting for levels and is not effected by the settings for the other speakers. Again, these levels should initially be determined by the auto calibration process or via the use of a SPL meter. You cannot accurately determine the correct levels to use by ear.

Yes, the amp does know the existence of my sub and it is outputing sound, I can set its separate level in the amp to +10dB (max) and forget all the problem (keeping the gain on sub to 12 o'clock) but surely that is weird?

And then how about other speakers using other preouts? They suffer from low output as well....:facepalm:
 

dante01

Distinguished Member
Can't really comment or help you further unless you calibrate the output. The amp needs to be calibrated in accordance with your speakers's capabilities, your listening position and your rooms acoustics. The amp provides provision for this. You should also take time to read both the manual for the amp and the sub in order to ascertain how to configure them both correctly in order to calibrate them correctly.

If you really want to ensure the levels are correct, you'll need an SPL meter.
 

dante01

Distinguished Member
And then how about other speakers using other preouts? They suffer from low output as well....:facepalm:

The other speakers will be connected to speaker terminals and not reliant on pre outs. Pre outs are pre amplification and the speakers are powered by the internal amplifiers and not external amplification. The sub is active and has its own amplifier fed via the sub pre out.

The pre out level will be determined by the levels after correct calibration. The levels you are getting are still acceptable for line level, but not correctly calibrated as yet. Calibrate the set up and then look for faults if they exist.
 
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CEC

Standard Member
Right. Just tried several YPAO auto calibration.
With my sub gain set to 12 o'clock, the auto calibration balanced the sub level by +6.5dB and front channels by about -3dB.
It also changed the crossover to 160Hz and other speakers to 'LARGE'....

Tried again with a pair of active speakers (gain at 12 o'clock) on front preouts and removed all speaker wires. This time YPAO failed to detect the front speakers at all (the noise is certainly audible).

I am confused now...
 
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dante01

Distinguished Member
Right. Just tried several YPAO auto calibration.
With my sub gain set to 12 o'clock, the auto calibration balanced the sub level by +6.5dB and front channels by about -3dB.
It also changed the crossover to 160Hz and other speakers to 'LARGE'.

and how did it sound?

I'd manually adjust the speaker size and crossover settings. The 160Hz setting is rather high and may allow audio being sent to the sub to become directional. You don't mention the speakers you are using so cannot suggest a better frequency to use. You may also want to set the size of your speakers to SMALL. Speakers set as being large are determined to be full range and audio intended for the associated channels isn't filtered via the crossover setting. Speakers set to SMALL have the audio associated with them filtered via the crossover and frequencies below the crossover are redirected to the sub.
 

CEC

Standard Member
Yes, that sounded awful after the YPAO....

My point is: isn't the difference of about 9.5dB (balanced automatically by YPAO) bit too big? That means my sub is 9.5dB lower volume at 12 o'clock gain compared with other speakers?

The sub is Wharfedale SW150, fronts are Monitor Audio BX2s.
 

dante01

Distinguished Member
Yes, that sounded awful after the YPAO....

My point is: isn't the difference of about 9.5dB (balanced automatically by YPAO) bit too big? That means my sub is 9.5dB lower volume at 12 o'clock gain compared with other speakers?

The sub is Wharfedale SW150, fronts are Monitor Audio BX2s.

The calibration measures the SPL at the point where you placed the mic (listening position). It adjusts the levels so that the SPL is equal for all speakers as measured from the listening position. The only real way to determine if the calibration is correct is to use an SPL meter and manually measure the levels obtained from the listening position. For reference, 0db should roughly equate to 85db plus an additional 10 - 15db for the sub. Issues arise while trying to ascertain the correct settings for the sub because low frequencies are notoriously hard to quantify correctly.

Try a crossover setting of 60 - 80Hz and set the speakers to SMALL. Also set the LFE / Bass Out setting to subwoofer or BOTH and not FRONT.
 
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CEC

Standard Member
Thanks!

80Hz / SMALL / BassOut: SWF are the settings I used.

I believe the levels are set correctly by the YPAO as now I can actually sense the bass from the sub.

Maybe I am a fool but I still think it is bit strange to have such difference for the sub (+6.5dB) & other speakers (-3dB) to achieve the same level of volume at the listening position :S
 

dante01

Distinguished Member
Maybe I am a fool but I still think it is bit strange to have such difference for the sub (+6.5dB) & other speakers (-3dB) to achieve the same level of volume at the listening position :S

Why, do you believe the sub has the exact same amplifier as those used onboard the amp that are used to power the other speakers? Why would an external amp made by another manufacturer produce the same results as the internal amplification modules powering drivers made by yet another manufacture? This is not to mention the different distances involved and your room's acoustics ;)


Better to stop looking at the numbers and use your ears. If it sounds okay then it is okay regardless of what levels are used to achieve the end result :)
 
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