Seek an advice from expert for improvement of bass

[sunao]

Thank you for comments and suggestions. Sort of practice are needed to get more precise measurements. Since I put a mic on a chair, it must not be an equal level with speaker's height. I will check mic position and direction, and level with speakers.

Here is a rough/awful drawing of the room. Me ( ) is in a corner of reverse-L shape room, speakers (white circles) are in a posing of center of room...but I cannot put any of my stuff in a pink area. That's why I say 5m - 8m distance. I can come close for sure, to shape a regular triangle, then each side will become about 2m length.

 

[ozzy9832001]

Any chance of centering the speakers a bit more so they are closer to centered? The difference in side-wall distances could cause some issues with stereo imaging and other anomalies.

 

[Flexecutioner]

This HSU has speaker-level pass-through which would give you the ability to high-pass your speakers:

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Perhaps I'm missing something, but using the high-level inputs on this sub won't help with high-pass filtering OP's speakers.

 

[Keith_W]

May I suggest you try this configuration:

The advantages of doing this:

- No sidewall reflections from the speaker
- Corner loading the speaker will improve the bass
- Rear wall reflections will be scattered around the room and not directed back towards you
- The left and right speakers are symmetrical as far as room boundaries are concerned (the way you have it now has the right speaker too close to the wall).

If it turns out that you need a sub, you could place it in the bottom right corner. That will load the room even more and you could get away with a single smaller sub.

Of course, your room configuration might not support this. If not, let us know what your limitations are and we may be able to come up with more ideas

 

[tmtomh]

I think you have only two options:

1. Experiment with positioning the speakers - for example as @Keith_W writes above - to try to take advantage of room reinforcement.

Or

2. Get a subwoofer.

You can definitely EQ the bass on your speakers, but given their lack of low bass, EQ'ing them below their F3 point is probably going to increase distortion, so you'd be better off with a subwoofer to handle those frequencies.

My only other thought is, given the measurements you've shared, instead of EQ'ing up the bass and treble, why not just EQ down all the frequencies in between, and see if that improves your perception of the overall frequency balance? Of course then you'd have to turn up the volume a bit - there's no free lunch - but in general it's usually better to attenuate with EQ rather than boost if you can.

 

[sunao]

Now I had a time to come back.
But I realize I cannot re-layout my position as @Keith_W suggested. I haven't put on a drawing, but I have a sofa in my listening position, then I cannot move it there. It is hard to *optimize* whole of my life style to the audio in reality ... ;-)
Anyway, I can do as @ozzy9832001 suggested, make a few more inches of extra space right side of right speaker. Again, that kind of small changes are only I can do.

This time, I put my mic to the equal level with tweeter of M105. Both speakers face to the mic aligned with regular triangle of 2 to 3 m. I measured three times for each test condition, then apply 1/6 smooth and averaged against measurement data. ( Just follow what miniDSP.com tells at here )

I have a couple of charts to be shared :

My Rotel A11 has tone control, and it says bypass, boost, and max. Without thinking much, I use 'bypass' always. But I have measured them.
SPL goes up bypass < boost < max order, but it is same effect as volume control? I don't know what a tone control means in fact.

Rotel A11 has bass control too.SPL increases bass+1 < base+2 < ... < base+10 order for sure. (^^)/, but what I wanted is to increase 40 -60Hz. Little different.

Now I am writing this, using 'bypass' tone control with '+3' bass control. What I want to feel is Contrabass, yet to come. When we listen that instruments at live, you feel you are vibrating. I would like to get that but maybe not possible with my setup.

As always suggestions are welcome.

 

[Chrispy]

Now I had a time to come back.
But I realize I cannot re-layout my position as @Keith_W suggested. I haven't put on a drawing, but I have a sofa in my listening position, then I cannot move it there. It is hard to *optimize* whole of my life style to the audio in reality ... ;-)
Anyway, I can do as @ozzy9832001 suggested, make a few more inches of extra space right side of right speaker. Again, that kind of small changes are only I can do.

This time, I put my mic to the equal level with tweeter of M105. Both speakers face to the mic aligned with regular triangle of 2 to 3 m. I measured three times for each test condition, then apply 1/6 smooth and averaged against measurement data. ( Just follow what miniDSP.com tells at here )

I have a couple of charts to be shared :

My Rotel A11 has tone control, and it says bypass, boost, and max. Without thinking much, I use 'bypass' always. But I have measured them.
SPL goes up bypass < boost < max order, but it is same effect as volume control? I don't know what a tone control means in fact.
View attachment 305243View attachment 305244

Rotel A11 has bass control too.SPL increases bass+1 < base+2 < ... < base+10 order for sure. (^^)/, but what I wanted is to increase 40 -60Hz. Little different.
View attachment 305241View attachment 305242

Now I am writing this, using 'bypass' tone control with '+3' bass control. What I want to feel is Contrabass, yet to come. When we listen that instruments at live, you feel you are vibrating. I would like to get that but maybe not possible with my setup.

As always suggestions are welcome.

You still have a way to use bass control when you're bypassing tone control?

 

[ZolaIII]

OK now that looks probable and as it should look. It's not that you don't have bass, you do have bass deficit to about 3 dB so +3 is about right. It is that they are way too bright so that should go trable - 3 at least regarding tone controls. Seams they start to compress (230~400 Hz) also when you pass 80 dB SPL in low region so I am afraid with those you will have to go to near field 1 m distance to get a reference level of 86 dB if that's possible.
What you really need to do is implement DSP to your system (either software solution or standalone hardware one). First order of business would be to PEQ most prominent peaks (110 Hz and 2.5 to 4.5 KHz range one's). Then do measurements and full PEQ or FIR correction. That's about it. If you want far field you need bigger speakers, sub's will help anyway but only in low to sub bass region. Luckily you have peek in 100 Hz region and not a deep which is much harder to address.

 

[sunao]

@Chrispy yes. it says tone enabled then choose bass +3.

 

[ZolaIII]

@Chrispy yes. it says tone enabled then choose bypass +3.

Bypass should bypass every alteration from tone controls and such so don't be surprised seeing us scratch our heads about that.

 

[Chrispy]

@Chrispy yes. it says tone enabled then choose bypass +3.

Yeah that makes no sense to me, if it's bypassed, it's bypassed.....but maybe the manual/control labels are odd? Can you point me to the part of the manual that covers tone control and bypass?

 

[ozzy9832001]

You may need a subwoofer to hit those really low notes. Your speakers seem to roll off fairly sharp at 50 hz. Any type of bass is capable of being tuned down to about 40hz. Those are the notes you really start to feel. Do you feel the bass drum? Does it sound more like a thud or a thump?

 

[sunao]

@Chrispy : let me correct my typo first: it says tone enabled then choose bass+3.

Rotel A11 recently released mkII, but manual for A11 Tribute is here:

https://rotel.com/sites/default/files/product/manuals/a11_tribute_om_en.pdf

Tone Control
The A11 Tribute features 4 different Tone Control options to provide a wide array of listening options. The options include a BYPASS mode that disables the Bass and Treble controls for the most direct audio path, ENABLED mode that allows user selectable Bass and Treble settings and ROTEL BOOST and ROTEL MAX modes supporting optimized configurations for multiple listening environments and styles.

SO, precisely, I choose 'enabled' mode and put bass+3. thank you for pointing out

 

[Chrispy]

@Chrispy : let me correct my typo first: it says tone enabled then choose bass+3.

Rotel A11 recently released mkII, but manual for A11 Tribute is here:

https://rotel.com/sites/default/files/product/manuals/a11_tribute_om_en.pdf

Tone Control The A11 Tribute features 4 different Tone Control options to provide a wide array of listening options. The options include a BYPASS mode that disables the Bass and Treble controls for the most direct audio path, ENABLED mode that allows user selectable Bass and Treble settings and ROTEL BOOST and ROTEL MAX modes supporting optimized configurations for multiple listening environments and styles.

SO, precisely, I choose 'enabled' mode and put bass+3. thank you for pointing out

LOL that makes a lot more sense! Just what are the parameters of your bass control?

 

[sunao]

Now I have measured treble control for negative (0 to -10) as suggested by @ZolaIII
I choose tone control bass+3 and treble-5 (red, no.6 in legend) for now.

Let me spend weekend with this. I do envy others... watching for subwoofer and miniDSP web page in parallel
Thanks experts for watching and suggestions.

 

[ZolaIII]

Now I have measured treble control for negative (0 to -10) as suggested by @ZolaIII
I choose tone control bass+3 and treble-5 (red, no.6 in legend) for now.

View attachment 305479View attachment 305480

Let me spend weekend with this. I do envy others... watching for subwoofer and miniDSP web page in parallel
Thanks experts for watching and suggestions.

It does look much better, hopefully it will also sound like that to you. It's a big improvement for now. Slowly work towards what you like regarding what you have and what you want when it comes to equipment. If it's acceptable there are great DSP software solutions even for free like EQ-APO and deacent measurement microphone ain't all that expensive. Best regards and enjoy it.

 

[neRok]

You are lucky that there is spinorama data for your speakers, because you can download that data and import the estimated in room response curve in to REW, and use that to find where you speakers aren't performing optimally in the room, like I did here. You should SPL match the EIRR to where your speakers measure roughly equal, so around about 1kHz looks good. Then you might find it looks something like this;

Your speakers don't go super low, so you may need a subwoofer regardless. But I have a suspicion that the room is costing you bass at ~45Hz. You should use the Room Sim feature in REW to estimate the main rectangle area of your room.

If this reveals that 45Hz issue is because you are sitting in a room mode, then even adding a sub won't fill in the null properly. However, you might find shifting the listening position or speakers slightly could help.
Alternatively, the null could be to do with your listening position to back wall relationship, like I found can happen in this thread. Again, moving the listening position could help.

 

[sunao]

Thanks for all the helps. It's a fun to measure, adjust and feel the difference.

@Apesbrain I have a question for your "ps" comment. Does the 'overdrive' happen if I put miniDsp in between source (CD, LP etc) and amplifier (Rotel)? Or using Rotel pre out as a source for miniDsp? (I don't have power amplifier BTW) if I need to have power amplifiers or active speakers for miniDsp, that brings me another story.

@neRok room simulator may be next fun part. Let me play with it to seek 40 - 50 hz gain.

 

[Apesbrain]

Does the 'overdrive' happen if I put miniDsp in between source (CD, LP etc) and amplifier (Rotel)? Or using Rotel pre out as a source for miniDsp?

Clipping (what I earlier called "overdrive") is caused when the power amp section or external power amp is driven beyond its ability to provide a signal free of audible distortion. Your Rotel is rated at a clean 50 WPC which may not be enough when you consider that your Revel speakers are of "low-ish" (86 dB) sensitivity and every +3 dB of EQ demands twice the output power.

It is possible to revise your listening configuration as illustrated below? This might give you a more pleasing result with your existing equipment.

 

[sunao]

@Apesbrain thank you for the explanation,