Dry bass

[Alice of Old Vincennes]

My first impression of that graph is that you have way too little bass full stop. You seem to have EQed out all the room gain maybe? Personally my room curve climbs from 200Hz, and is 12dB up by 40Hz. That’s for 75dB average listening levels. A lot of the “punch” is in the 80-150 range, so just turning up the gain on your subs wouldn’t help. Just a hot take, maybe I have misunderstood the graph,

Exactly. Punch above the crossover. I define punch as clean bass. I think we discern distortion at low frequencies. Integrating subs with mains is extremely difficult.

 

[Bjorn]

Read some....but wtf is dry bass let alone wet bass particularly in technical terms?

Bass can't really be too "dry". If the decay in the lows is super short and it's completely free from resonances and ringing you have incredible bass and something that people would have an experience of life when hearing it.

However, too "dry" is a term appropriate for the upper frequencies. Typically overdampened treble area and possibly also midrange. Something that for instance happens if the treatment in the room is too bandlimited or if there's simple too much absorption of mids and highs.

 

[sigbergaudio]

Five pages and we still haven't seen proper measurements of the basic response?

Dry bass

THANK YOU! I did a search for the "Pultec-punch" and came across a few resources, including this thread on ASR where you contributed. I am trying to wrap my head around exactly what it is and how it works. I think the easiest way to try it out is to download that Puigtec plugin before I try to...

www.audiosciencereview.com

 

[Keith_W]

Five pages and we still haven't seen proper measurements of the basic response?

Dry bass

THANK YOU! I did a search for the "Pultec-punch" and came across a few resources, including this thread on ASR where you contributed. I am trying to wrap my head around exactly what it is and how it works. I think the easiest way to try it out is to download that Puigtec plugin before I try to...

www.audiosciencereview.com

What do you mean? I have posted several FR curves, phase, impulse, and step response. What do you want to see? The uncorrected response? Something else?

 

[Bjorn]

You should post uncorrected response of each channel with either 1/24 or 1/12 smoothing and with a resolution on the Y axis with 5 dB. And waterfall of both channels from 15 Hz to 400 Hz. You could also measure at stomach and feet height and post the waterfall of this. All uncorrected.

 

[Bjorn]

Have you guys heard Wilson speakers? Now, I wouldn't say I am a fan of Wilsons, but one thing they do very well is punchy, physical bass. Wilsons hit you in the chest, and they do it with smaller drivers than my subwoofers. I have no idea how they do that, so if someone knows, I would be all ears.

They have a clean time domain behaviour in the lows. No overhang or ringing, because the cabinet is resonant free. The same principle applies for the room which many disregard.

 

[Tangband]

For some time now, I have a bass problem. The bass does not sound impactful or physical, it's just ... there. For context, I have 4x 12" Rythmik sub drivers built into two subwoofers, crossed over at 80Hz, with DSP provided by Acourate. If I turn the subs louder, it sounds unbalanced and there is way too much bass (but strangely, it still seems to lack punch). I have visited friends with systems that sound balanced, but the bass has a physical quality, it seems to actually pressurize your lungs and vibrate your body.

I am wondering whether it is because my bass is too dry. My Rythmik subs are servo controlled, so they certainly have the potential to create dry bass. Take a look at this:

Notice how the RT60 falls below the target at 110Hz. I am aware that RT60 has no meaning for small room acoustics because even large "small rooms" like mine (measures 6m x 7m x 3m, or approx 20' x 23' x 10') do not produce reverberant fields.

I am not sure where the blame lies. For those systems that have impactful bass, they were all using much bigger subwoofers than mine - one guy has four 15" subs, and another has two subwoofers, with each subwoofer containing 3x 12" drivers. So I am not sure whether my result is due to using smaller subs, or whether it is because my bass is too dry.

Is anybody aware of a way to wetten the bass whilst leaving the rest of the FR untouched? I know there is a procedure in Acourate for generating a VBA, and I am wondering if I could modify that to create reverb instead of cancelling bass.

Sounds like you must reinstall your main speakers . Your bass quality is dependent on the quality from your main speakers because a bass guitarr plays frequencies between 40 - 8000 Hz. I suggest this because correct positioning of the speakers in the room has a bigger impact on the sound quality than any roomcorrection. Wrong installement of stereo speakers is the most common problem for less good sound in a home. An equilateral triangle as a rule of thumb is a bad idea.

1. Turn off your subwoofers.

2. Install your main L and R speakers in the room where they sound most natural and can play very good bass without subwoofers. Use a favorite record for this, with real musicians playing together.

You can play with the distance between the speakers, toe in, and the distance to the front wall behind the speakers.
You probably have the front speakers to far apart. Use your ears when doing this - and there are no rule of thumbs because every room is different .

3. For optimal integration for the subs to the main speakers you need your external dsp crossover with both HP and LP slopes. Start with 80 Hz but anything between 60 - 90 Hz might sound better. At those low crossover frequencies, you could try an odd order slope , like 18 dB/oct or higher order. Your room response that way may be better with more perceived impact. You could try a 18/30 ( HP and LP ) electrical slope crossover - this will give a better room response than an even order crossover and this will give an acoustical 30/30 dB oct filter. Your main speakers should be closed.

4. If you have your listening position in a sofa closed to the wall, it might be beneficial to move the sofa forward to have more than 40 cm distance to the back wall.

 

[Bjorn]

Sounds like you must reinstall your main speakers .

1. Turn off your subwoofers.

2. Install your main L and R speakers where they sound most natural and can play very good bass without subwoofers.
You can play with the distance between the speakers, toe in, and the distance to the front wall behind the speakers.
You probably have the front speakers to far apart. Use your ears when doing this - and there are no rule of thumbs because every room is different .

3. For optimal integration for the subs to the main speakers you need an external active crossover with both HP and LP slopes. Start with 80 Hz but anything between 60 - 90 Hz might sound better.

In you are driving your main speakers fullrange without crossover, you must make your main speaker closed.
After that , switch the + and - on the main speaker terminals. Now you need a 24 dB/oct LP electrical crossover for the subwoofers and anything between 60-90 Hz will probably sound good with good integration . You now have a acoustical 24/24 dB/oct crossover for your speaker at the frequency where your main speakers drop off.

Having a dsp crossover for the subs might be problematic If the dsp latency is to big . The result if thats the case is a less powerful sound.

Been there, done that

Please read the thread before you post something.

 

[Tangband]

If you get the main loudspeaker installement correct and the acoustical crossover points to the subwoofers correct then you should aim for a roomcurve thats slightly rising below 150 Hz . Your eyes sees the room, you expect a certain roomgain and your brain will not like a flat bass response because of this.

 

[Tangband]

I have money, I just don't like spending it! You may be right, but I prefer to exhaust all free options first, before I move on to cheap options. The last step is to take the expensive option.

As you can see from the curves, I can get the bass really nice and flat, and I can turn up the bass until the house starts to rattle. But even though the volume is loud, it still lacks physical impact! Have you guys heard Wilson speakers? Now, I wouldn't say I am a fan of Wilsons, but one thing they do very well is punchy, physical bass. Wilsons hit you in the chest, and they do it with smaller drivers than my subwoofers. I have no idea how they do that, so if someone knows, I would be all ears.

The Wilsons you listened to were probably correct installed in the room . They have rigid and very low coloration cabinets . And I suppose they were standing on spikes ?
You can play with some colorations ( such as spikes below the main speakers ) to get the perceived impact of the sound better. The stereosystem is very flawed and because of this there is no ”perfect sound” to be had with only two channels.

For optimal perceived pace using two stereo loudspeakers you can play with a slightly elevated level at 1,7 kHz , + 2 dB Q=3 and a small dip centered at 3 kHz , -2 dB, Q=3 . ( This is only relevant If your speakers are already flat. To do this, you must measure only one speaker from about 1 meter distance )

Here is the frequency response for Wilson Audio Alexx V:

Wilson Audio Specialties Alexx V loudspeaker Measurements | Stereophile.com

Sidebar 3: Measurements Because of the Alexx V's size and bulk, I measured its performance in Jim Austin's listening room. I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Wilson Audio Alexx V's frequency response in the farfield, an Earthworks QTC-40 microphone...

www.stereophile.com

 

[mcdn]

What do you mean? I have posted several FR curves, phase, impulse, and step response. What do you want to see? The uncorrected response? Something else?

You posted some RT graphs which looked like they had an FR component as well. The FR looked awful on those, so some people asked if you had addressed it. Then you posted an FR graph that showed an absolutely huge dip exactly at your bass/mid xo frequency of 500Hz, also from Acourate. Several people queried if it was right and asked for you to do an MMM measurement with REW, because that is the standard for in-room measurements around here. All the other plots and chat are pointless if the basic FR of the system isn’t clear.

So. We want to see an MMM based FR of the system as you usually use it, from your approximate usual listening position. 50dB on the vertical axis, 75dBSPL volume at the mic position. Because we want to help!

 

[boxerfan88]

May I suggest to experiment bumping up the 60Hz-150Hz area by about 3-4 dB, and see if you get the chest thump you’re looking for?

If it doesn’t work, maybe posting the mdat of a short sweep from 20Hz to 500Hz (before & after boost) may help us figure out if there is some cancellation going on in that chest thump zone.

 

[Geert]

Wilsons hit you in the chest, and they do it with smaller drivers than my subwoofers. I have no idea how they do that, so if someone knows, I would be all ears.

By using smaller drivers than you're using in your subs, in larger enclosures than you're using? Resulting in tight bass (low Q factor ) with good natural low end extension (not EQ-ed like most small sub's do) and low distortion? If turning up your subs results into a bloated sound, maybe the subs don't sound that well? Are you sure the subs work as designed (servo circuit working well, enclosure volume as designed, distortion under control)? I've heard lots of poor subs in my life and what typically happens is that the level is reduced to a lower level than ideal to mask their terrible sound.

 

[Geert]

Something to contemplate for the people that are convinced the issue is to be found in the mid range; I can have subs produce the most earth shaking and stomach-turning bass with a high cut filter set on the total system (not just the subs) at 120Hz. And if I read it well, that's where the OP is after: "physical quality, it seems to actually pressurize your lungs and vibrate your body".

Still not sure? Show me a speaker that can produce the effect the OP is after with a low cut at 70Hz. Such speakers can thump, but can they vibrate your body?

 

[Dumdum]

If you’re using two channel Dirac it’s very possible your subs aren’t in phase and Dirac corrects for the phase response but still doesn’t put the subs in phase, I use Smaart for setting up home audio setups with Dsp, this way I can see phase anomaly’s… have you measured the phase of mains and subs at the listening position?

Listening position in the room can also present issues with sub bass and midbass and how they present

Also increasing level of the subs will change the phase relationship of subs to mains as you will raise the crossover by raising the level, so unless the phase was nailed on prior changing levels may accentuate the problem

 

[Geert]

Then you posted an FR graph that showed an absolutely huge dip exactly at your bass/mid xo frequency of 500Hz

It's a very narrow dip on a frequency that has nothing to do with " pressurize your lungs and vibrate your body". A lot of speaker setups have a serious dip in the mid range due to SBIR (like front wall cancelation), and as long as it's narrow it doesn't bother that much.

All the other plots and chat are pointless if the basic FR of the system isn’t clear.

To me and different other people the FR is clear. It's to flat, levels of the lows is ... to low. No need for higher resolution graphs to notice that.

 

[Sokel]

Something to contemplate for the people that are convinced the issue is to be found in the mid range; I can have subs produce the most earth shaking and stomach-turning bass with a high cut filter set on the total system (not just the subs) at 120Hz. And if I read it well, that's where the OP is after: "physical quality, it seems to actually pressurize your lungs and vibrate your body".

Still not sure? Show me a speaker that can produce the effect the OP is after with a low cut at 70Hz. Such speakers can thump, but can they vibrate your body?

Stomach is different than chest,needs lower,as feet (trousers flapping) needs even lower.

Speakers that can't go low but still give slam (chest punch) are the old broad,big ones,usually with a 10" mid and 12" or 15" bass drivers but with weak motors (strong back then though,weak by today's standards).
They went down to 50's,40's at the best but try to listen "Moonchild" on them at elevated level and you could get a heart attack.

 

[Geert]

Stomach is different than chest,needs lower,as feet (trousers flapping) needs even lower.

The OP mentioned "vibrate your body", that includes all organs

They went down to 50's,40's at the best but try to listen "Moonchild" on them at elevated level and you could get a heart attack.

Yes, and add some room gain and you have a more than capable low end behavior. And 50Hz is a long way from 500Hz.

 

[Sokel]

The OP mentioned "vibrate your body", that includes all organs



Yes, and add some room gain and you have a more than capable low end behavior. And 50Hz is a long way from 500Hz.

Room would help,yes,but we're talking about drivers with minimum x-max,the 40 or 50Hz extension could be at f10 easily,big cabinets also helped but none of them ever vibrated a room but could get your chest explode.

And the 500Hz thing is irrelevant,just a side observation as it seems odd,the debate is at a strong 80-200Hz ability vs the lower one.

 

[Geert]

Room would help,yes,but we're talking about drivers with minimum x-max,the 40 or 50Hz extension could be at f10 easily,big cabinets also helped but none of them ever vibrated a room but could get your chest explode.

And the 500Hz thing is irrelevant,just a side observation as it seems odd,the debate is at a strong 80-200Hz ability vs the lower one.

Sure, that brings us back to what I said on page 2: "Physical bass is to be found below 60Hz, but punch is more around 80Hz". As we can't experience what the OP hears, it's up to him to do the finetuning.