Yamaha Straight Enhancer/5ch Enhancer

[VASKION]

I was playing around lately with these two modes of my receiver and found out that my speakers sound way better when these features are turned on. The AVR is rather old (RX-V371) and does not have so many bells and whistles as the new modern stuff. The manual is not very descriptive on what actually is happening in these situations. It says that these modes will "restore" some lost frequencies and information when mp3 or other compressed format is played. The manual of my AVR is very similar to this one -> https://manual.yamaha.com/av/18/rxv685/en-US/316648971.html

Trying to figure out what actually is going on with these modes, I did the following:
1. Connect my laptop through the headphones jack to the receiver audio input with RCA cables
2. Open Adobe Audition, go to Effects -> Generate -> Tones... and generated tones with default settings and only change the frequency from 20 to 50 with 5Hz increment
3. Play these tones from Audition software through the receiver and change modes - Straight Enhancer / 5ch Enhancer / Straight (I guess this one should be the Pure Direct on my AVR)

My front speakers are rated from 37Hz to 30kHz (Yamaha NS-F140). Yes, I know this is most probably overrated, most people also say that Yamaha's strength is not speakers and it may sound silly to play around with such cheap crappy system. Still I wanted to check what exactly happens when these modes are turned on and why they sound so much better. I don't use any EQ on both the laptop (used for playing music) and the receiver.

So, here is the result:
1. Straight Enhancer: 20Hz - no sound; 25Hz - like whisper but there is something coming out of the speakers even more audible when I go closer to it; >=30Hz clearly audible even from 2.7 meters away (MLP)
2. 5ch Enhancer: exactly the same as 1.
3. Straight - 35Hz and below - no sound at all, even when I go to the speaker and put my ear right in front of the driver; >=40Hz - audible from MLP but lower than 1. and 2.

I was hoping that some of you more experienced than me could help me determine what I am doing wrong in this test. I thought that Straight in my case should be the better and more transparent mode compared to any of the other which engages the DSP. Instead it actually turns out that this way the AVR kind of "robs" a lot of the sound capability of my speakers.

 

[3db]

Think of the enhancer as an old fashioned loudness button where it boosted bass and treble. Thats all its really doing and for low listening levels, it is safe to use. But do NOT listen to music at loud levels with this feature engaged. It will cause damage to the woofers. I experimented with the feature through a pair of PSB 400 speakers which have 6.5 woofers in a ported box. I noticed that my woofers were bottoming out (reached their excursion limit) and unable to play the deepest part of the bass in a particular song. I turned off the enhancer feature and although the bass was weaker, the 400s were able to play the entire bass of the song hitting the lowest part.

The AVR isnt robbing you of the sound. Its simply passing the information to the speakers and with the enhancer engaged, is artificially boosting the bass. Your speakers are limited to the bass it can play. The easiest fix is to get a subwoofer into your system.

 

[Am_P]

Think of the enhancer as an old fashioned loudness button where it boosted bass and treble. Thats all its really doing and for low listening levels, it is safe to use. But do NOT listen to music at loud levels with this feature engaged. It will cause damage to the woofers. I experimented with the feature through a pair of PSB 400 speakers which have 6.5 woofers in a ported box. I noticed that my woofers were bottoming out (reached their excursion limit) and unable to play the deepest part of the bass in a particular song. I turned off the enhancer feature and although the bass was weaker, the 400s were able to play the entire bass of the song hitting the lowest part.

The AVR isnt robbing you of the sound. Its simply passing the information to the speakers and with the enhancer engaged, is artificially boosting the bass. Your speakers are limited to the bass it can play. The easiest fix is to get a subwoofer into your system.

I don't think it is just a simple case of boosted bass/treble, some loudness modulating feature or a variant of dynamic eq. Most receiver manufacturers (Marantz, Pioneer, etc) have an equivalent feature that they market for compressed music sources. Until someone audits their proprietary algorithms, it is anybody's guess as to what they really do.

 

[VASKION]

Think of the enhancer as an old fashioned loudness button where it boosted bass and treble. Thats all its really doing and for low listening levels, it is safe to use. But do NOT listen to music at loud levels with this feature engaged. It will cause damage to the woofers. I experimented with the feature through a pair of PSB 400 speakers which have 6.5 woofers in a ported box. I noticed that my woofers were bottoming out (reached their excursion limit) and unable to play the deepest part of the bass in a particular song. I turned off the enhancer feature and although the bass was weaker, the 400s were able to play the entire bass of the song hitting the lowest part.

The AVR isnt robbing you of the sound. Its simply passing the information to the speakers and with the enhancer engaged, is artificially boosting the bass. Your speakers are limited to the bass it can play. The easiest fix is to get a subwoofer into your system.

If it is just a bass boost or something I could try the same test but this time will turn the volume of the AVR up to some extent and will check if I am able to hear the same frequencies in Straight mode.

I tried this test at around -36dB volume. I have listen to music this way till -25-ish volume or something and the speakers sounded fine. No issues. But yes, I totally agree with you that I will have to be more careful while using these settings close to maximum volume.

I also just tried the same test at the high frequencies. In Straight mode there is no sound after 15kHz. With the other two modes I am able to hear sound from the speakers up till 23kHz. I will redo the test at -25dB or even -10dB again to check if there will be any change.

Yes, agree on the sub. I am currently in the process of upgrading the whole system - both AVR and speakers so I guess after that will have to see about the sub...

 

[lovinthehd]

This enhance mode is different from YPAO Volume? I take it using both together would not be a good idea?

 

[VASKION]

This enhance mode is different from YPAO Volume? I take it using both together would not be a good idea?

Yes, it is different. YPAO is trying to make room corrections after it measures how the whole system "sounds" and adjust the speakers frequencies curve. On some AVRs you have the option to tweak the YPAO EQ while on mine it is just on/off. Instead mine have another Graphical EQ with several predefined frequencies for every channel I can tweak up or down.

If the enhancer boosts low and high frequencies (maybe even the whole spectrum) it will still boost the unwanted ones that YPAO is trying to correct. So it probably makes sense to use them both at the same time. And if you have the option to tweak the YPAO EQ even further that could give you even greater result.

 

[lovinthehd]

Yes, it is different. YPAO is trying to make room corrections after it measures how the whole system "sounds" and adjust the speakers frequencies curve. On some AVRs you have the option to tweak the YPAO EQ while on mine it is just on/off. Instead mine have another Graphical EQ with several predefined frequencies for every channel I can tweak up or down.

If the enhancer boosts low and high frequencies (maybe even the whole spectrum) it will still boost the unwanted ones that YPAO is trying to correct. So it probably makes sense to use them both at the same time. And if you have the option to tweak the YPAO EQ even further that could give you even greater result.

YPAO Volume as I understand it is a loudness contour that varies with volume, similar to Audyssey's DynamicEQ. Sounds like the enhancer mode is similar at least. Is YPAO Volume not a feature in your avr?

 

[William Lemmerhirt]

I think the “enhancer” is not a frequency booster. It’s supposed to “restore” lost bits when using compressed music formats like mp3. Not a bass/treble booster.

Most AVR’s have a similar feature. Never really found them useful.

 

[VASKION]

YPAO Volume as I understand it is a loudness contour that varies with volume, similar to Audyssey's DynamicEQ. Sounds like the enhancer mode is similar at least. Is YPAO Volume not a feature in your avr?

No, I don't have YPAO Volume. I only have YPAO automatic speaker setup and its associated Parametric EQ.

 

[lovinthehd]

No, I don't have YPAO Volume. I only have YPAO automatic speaker setup and its associated Parametric EQ.

I guess that's something that they unlock on higher up models....believe it's been around for a while, tho.

 

[VASKION]

I think the “enhancer” is not a frequency booster. It’s supposed to “restore” lost bits when using compressed music formats like mp3. Not a bass/treble booster.

Most AVR’s have a similar feature. Never really found them useful.

Yes, that is exactly what I quoted in my first post from some AVR manual. I know most people find them useless. I just wanted to understand why they sound so much better on my system even when playing lossless music which should not benefit from any enhancer.

 

[William Lemmerhirt]

Yes, that is exactly what I quoted in my first post from some AVR manual. I know most people find them useless. I just wanted to understand why they sound so much better on my system even when playing lossless music which should not benefit from any enhancer.

Not saying useless. Just that I haven’t fount any benefits personally. My other point is that as a rule, they generally don’t add any bass or treble enhancement, to my knowledge. So I would not equate this to a ypao volume, or loudness shaper etc. I could be wrong about that, but I just don’t remember any reference to such a function wit other enhancers.
What is your source? Maybe it could use enhancing lol.

 

[VASKION]

Not saying useless. Just that I haven’t fount any benefits personally. My other point is that as a rule, they generally don’t add any bass or treble enhancement, to my knowledge. So I would not equate this to a ypao volume, or loudness shaper etc. I could be wrong about that, but I just don’t remember any reference to such a function wit other enhancers.
What is your source? Maybe it could use enhancing lol.

Mainly I use my laptop for playing music form my NAS (FLACs and mp3s encoded with maximum quality) through MusicBee application. No filters or EQ used in the whole chain. I use my LG 65C1 TV as well with its default media player app to play the same music from the NAS. Even tried the FM tuner of the AVR. All sources sound way better with enhancer set to on. It is difficult to describe it but when I switch to Straight all sound dull or maybe flat is the correct word.

That's why I tried to generate the frequency tones in Adobe Audition and play them one by one to see if it makes any difference and how.

 

[lovinthehd]

Is YPAO eq active in straight mode? I wish Yamaha didn't have a language for settings unique to their gear....

 

[VASKION]

Is YPAO eq active in straight mode? I wish Yamaha didn't have a language for settings unique to their gear....

No, it is not. I have a separate setting for this one and keep Equalizer in the speaker setup menu to Off all the time.

 

[William Lemmerhirt]

No, it is not. I have a separate setting for this one and keep Equalizer in the speaker setup menu to Off all the time.

Is that the manual EQ? Or ypao EQ?

 

[William Lemmerhirt]

Is YPAO eq active in straight mode? I wish Yamaha didn't have a language for settings unique to their gear....

Been a frustration of mine for YEARS!!!!!

 

[William Lemmerhirt]

Mainly I use my laptop for playing music form my NAS (FLACs and mp3s encoded with maximum quality) through MusicBee application. No filters or EQ used in the whole chain. I use my LG 65C1 TV as well with its default media player app to play the same music from the NAS. Even tried the FM tuner of the AVR. All sources sound way better with enhancer set to on. It is difficult to describe it but when I switch to Straight all sound dull or maybe flat is the correct word.

That's why I tried to generate the frequency tones in Adobe Audition and play them one by one to see if it makes any difference and how.

This is interesting. In which way do they sound “way better?” Not saying they don’t. Just trying to get a feel for what you’re hearing.

 

[3db]

I think the “enhancer” is not a frequency booster. It’s supposed to “restore” lost bits when using compressed music formats like mp3. Not a bass/treble booster.

Most AVR’s have a similar feature. Never really found them useful.

My experience playing with it was the net effect of a bass and treble boost. I don't put to much faith in the restoration of bits. One cant restore whats been taken out. I leave that setting off and never use it.

 

[3db]

No, it is not. I have a separate setting for this one and keep Equalizer in the speaker setup menu to Off all the time.

YPAO is on even in straight mode. All straight mode does is to output to all channels that it receives an input signal for. There is no muxing of any kind. I In your case and I do it as well, I turn YPAO off in the EQ setting when listening to 2 channel music.

If it is just a bass boost or something I could try the same test but this time will turn the volume of the AVR up to some extent and will check if I am able to hear the same frequencies in Straight mode.

I tried this test at around -36dB volume. I have listen to music this way till -25-ish volume or something and the speakers sounded fine. No issues. But yes, I totally agree with you that I will have to be more careful while using these settings close to maximum volume.

I also just tried the same test at the high frequencies. In Straight mode there is no sound after 15kHz. With the other two modes I am able to hear sound from the speakers up till 23kHz. I will redo the test at -25dB or even -10dB again to check if there will be any change.

Yes, agree on the sub. I am currently in the process of upgrading the whole system - both AVR and speakers so I guess after that will have to see about the sub...

Heed my warning though about using the enhancer at loud volume levels. You will overdrive your woofers on bass heavy material.