One Sub For Music Only

[KEW]

I think you are having a similar experience to what I often have with ported subs (or sealed subs designed to behave like ported subs).
The problem is these subs are often designed to have a flat frequency response in an anechoic chamber.
Once you put them in your room, the lower frequencies are often emphasized via room gain and you end up with a lower bass heavy FR in your room.
When asked about what aspect of a sub provides a perception of fast, tight bass, sub guru, Josh Ricci said it was having more higher frequency than lower frequency output. Thus, if your sub has a flat FR anechoically, once room gain is added, it is probably just the opposite - more lower frequency than upper frequency output which would result in a perception of slow sloppy bass!
So, what you are looking for is a curve with more SPL in the 40-50Hz range than it has in the 20-30Hz range. Looking at the charts that ShadyJ linked above, I would say the Sealed mode with Q=0.5 is probably your best option. Give that a try.

Also, you can try moving the sub into the center of the room to reduce room gain. Consider that a test, since you probably won't want to locate it there permanently. However, if that gets things perfect, you might want to consider using your sub as an end table.
Let us know if that helps!

IMHO, the extra bass at the lowest frequencies can be fun for HT Action films, but it a big detraction from SQ with music. If I am correct in my understanding of your situation, I would generally use sealed mode with Q=0.5, but if I want to go for the full-blown HT experience, I would switch to one port open to get the thrill and excitement of that deep bass!

 

[Chief2001]

Thanks for all of your input..much appreciated!

I wil run the REW this weekend and see what I find.

I could move the sub to the centre of the room to see how it works. I will give that a try!

 

[shadyJ]

For me in my room, the spot that nets the best overall response for a single subwoofer is right behind the listening position. But it can be different depending on individual circumstances. Here is a recent article that illustrates some of the challenges of subwoofer placement. Here is an older audioholics article that is slightly technical but really gives you an idea of the challenges of trying to get a smooth bass response (spoilers: it's really hard to achieve with just a single sub).

Measure different subwoofer locations throughout your room and stick with the one that produces the flattest response, or has the least severe nulls. The peaks can be tamed through equalization, but the nulls aren't all that amenable to equalization.

 

[Chief2001]

Hi All,

I tried running REW with the current placement of my sub. I ended up turning the crossover frequency up to just under 80 HZ, EQ1, one port open, Q .5 and volume about 12 o'clock to even the curve out and get it close to the reference level (much easier from 80 HZ down). This seemed to take the dip around 60 HZ out and even things out better. However, I am still not getting as "tuneful" and impactful bass as I would like. The electric bass guitar (Stanely Clarke School Days) was not very clean in terms of bass notes. I am also getting no real physical (chest thump) impact. And, as a final thought/concern, while, when I turn the system up to loud volumes, the bass seems to be quite loud and full (room shaking) but main speakers do not seem as loud as they normally do.

So, a couple of thoughts...when I looked at the Room SIM on REW, there is one other feasible position for the sub that appears to automatically provided a flatter response and is just to the side of my listening position, facing the main speakers. Do you think this position would help with bass tunefulness and impact?

I am running my speakers full range, with no high pass filter. As a reminder, my speakers are 89 db, 4 ohms, 55Hz -3db and are powered with a 45 watt/channel tube amp. Would a high pass filter help to clean the bass up (are my speakers adding to the lack of tunefulness by playing full range with the sub) and open up my main speakers more? Or, by adding a high pass filter, am I just getting into more entanglement or trying to blend crossover frequencies? My main speakers, without the sub, play very tuneful bass, so I know it isn't them.

 

[shadyJ]

Can you post a sweep of just the sub, and also a sweep of the sub with the speakers? As for bass on Stanley Clarke, not many of his albums actually have a lot of bass in subwoofer frequency bands. It is mostly 60 Hz to 150 Hz, especially his older albums from the 70s and 80s. That stuff just doesn't do much with subs, it would only be tapping the subs at the very bottom part of its frequency spectrum, but most of the bass would actually be tackled with your main speakers.

 

[Chief2001]

Thanks shadyj!

Soooo, a sweep is an image of the recording done with REW? Sorry to expose my ignorance.

 

[Chief2001]

I think I see what you are getting at...are my main speakers giving me what I need with the music I listen to so that the sub could be set lower???

 

[shadyJ]

Thanks shadyj!

Soooo, a sweep is an image of the recording done with REW? Sorry to expose my ignorance.

Well, just a measurement of the frequency response, so yes.

 

[shadyJ]

I think I see what you are getting at...are my main speakers giving me what I need with the music I listen to so that the sub could be set lower???

You should end up setting your sub to where ever it sounds best to you, regardless of what the measurements say. However, you should try to achieve as flat of a frequency response as you can get to start with, to at least see what semi-accurate bass sounds like, and then go from there.

 

[Chief2001]

here is no sub

 

[Chief2001]

here is sub

 

[shadyJ]

Uh, I don't think you are taking those measurements quite right. You should end up with something that looks like this:

Can you describe your procedure?

 

[Chief2001]

Hey, sorry..life got in the way.

I go to RTA, I have the mic on the back of my couch about where my head is located for listening (not on a stand but on the couch), mic pointed 180 degrees toward the speakers. Then I hit the red record button.

 

[shadyJ]

Hey, sorry..life got in the way.

I go to RTA, I have the mic on the back of my couch about where my head is located for listening (not on a stand but on the couch), mic pointed 180 degrees toward the speakers. Then I hit the red record button.

Yeah it sound like you are not using REW correctly. Follow what this guy does. Don't use the RTA, that is something completely different than the measurements you want to be taking.

 

[KahunaB14]

"However, I am still not getting as "tuneful" and impactful bass as I would like. The electric bass guitar (Stanely Clarke School Days) was not very clean in terms of bass notes. I am also getting no real physical (chest thump) impact."

So I too just recently got my first real home theater setup going. If you see my thread called "PB12 initial thoughts & decision" you will see I struggle with the issue as you in terms of my expectations of a sub giving me the "chest thump" and kick drum "hit" and my new PB12-NSD not really delivering there.

I have have come to realize that the sub isn't really doing much for me for a lot of songs (can't hear a difference toggling it on and off). Mostly I think because the frequencies are too high. The string bass heavy songs (Norah Jones, Esperanza Spaulding, Jazz) do allow the sub to shine however. Some bass guitar too (Golden by Lady A). Def a lot of rap like 21 Savage, 3-6 Mafia etc. Search "bass" or "Sub" on Spotify and check out people's playlists.

But I too was expecting the sub to add "Hit" with a kick drum and no matter how I adjust mine it does not do that. I think the kick drum in most songs is up on the 80-100Hz region and so it is being handled mainly by the mains. And I have realized that unless you have some RF-7's or similar with large high powered (external amp) woofers you just aren't going to get that tactile "thump" like at a concert.

My experience reflects what KEW was saying about room gain. Running constant frequency tests (youtube) my PB12 is a LOT louder at 20-45 Hz than it is at 50-80Hz. Dramatically so.