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Subwoofer in a very small room: does it make sense?

daftcombo

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So, I have a 3rd system in a very small room (3 m * 2,5 m, that is to say 10ft * 8ft approximatively) for late night chill-out.
It is composed of a Sony DVD player, a JDS Lab Atom used as headphones amp and pre-amp for a pair of JBL 305p mkII.
In this room I mostly listen to piano, but also electronic music at times while browsing this site on my phone (I-F "mixed up in the Hague" for instance).

My question is: would there be any improvement with a JBL 310s subwoofer (or any subwoofer)? As I listen at very moderate volume, wouldn't it be better to have more bass in order to actually hear it?

Cheers.
 

Dumdum

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For me it’s more if there isn’t enough extension from the jbls and in that case you will certainly benefit from a subwoofer, that’s the question you should be asking yourself imo. I would be careful over selection of a sub or include a dsp if you have the capability to take measurements of the room and correct the response, smaller rooms are generally quite easy to generate bass in but being nearly square you may get a few issues with modal frequencys, how tall is the room?
 
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daftcombo

daftcombo

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For me it’s more if there isn’t enough extension from the jbls and in that case you will certainly benefit from a subwoofer, that’s the question you should be asking yourself imo. I would be careful over selection of a sub or include a dsp if you have the capability to take measurements of the room and correct the response, smaller rooms are generally quite easy to generate bass in but being nearly square you may get a few issues with modal frequencys, how tall is the room?
It is 2m60 high.
Yes I have a measurement mic and REW but it is useless in such a small room.


JBL305p mkii
  • Frequency Range:43Hz-24kHz
  • Frequency Response:49Hz-20kHz (±3dB), 43Hz-24kHz (-10dB)
 

Dumdum

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Well I manage to use a measurement mic in a car that’s way smaller so to say it’s useless in such a small room is a load of rubbish, it measures reflected sound (but it does that in a bigger room also) and all the stuff your ears hear, have you actually tried measuring the room or are you just assuming?

your room is off square but not by much so I’d be measuring and seeing what the response of the room is and then perhaps considering giving more information on the room, then people can give a more accurate information and answers
 

Juhazi

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JBL 305 is bass reflex, it has practically no bass below 40Hz. A 10-12" closed box subwoofer or a pair of them would be OK for you. You don't need large diameter or high power. A closed box sub with some EQ will give really good response down to 10-15Hz in your "cab". However modes around 60-100Hz will be very problematic! You will need your mic to find best placemement for speakers and ears! Room treatment for bass/modes is very difficult in such a small room.

https://www.svsound.com/products/sb-1000
 

Soniclife

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I use a small sub in a tiny room, I like it.

Do you have a sub in another room you can drag in for a trial?
 
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daftcombo

daftcombo

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I use a small sub in a tiny room, I like it.

Do you have a sub in another room you can drag in for a trial?

Yes I have another sub from an Altec Lansing 2.1 kit but it would be a bit difficult to try it with the JBLs because it is not meant to be used with anything else than its satellites. I would have to do a crossover in the miniDSP also, and use two DACs. Bit of a pain.
Perhaps I should just try the Altec kit with the sub in that room. Actually it used to be in not very bigger a room before, and there was no problem.

As for measurements with a mic in a car, I am very surprised! What kind of results did you get? Did you window anything?
 

Juhazi

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What is the problem you see with measurements in a small space? One can even put a mic inside a loudspeaker!
 

Dumdum

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Yes I have another sub from an Altec Lansing 2.1 kit but it would be a bit difficult to try it with the JBLs because it is not meant to be used with anything else than its satellites. I would have to do a crossover in the miniDSP also, and use two DACs. Bit of a pain.
Perhaps I should just try the Altec kit with the sub in that room. Actually it used to be in not very bigger a room before, and there was no problem.

As for measurements with a mic in a car, I am very surprised! What kind of results did you get? Did you window anything?
Well as much as ears/brain decide what we actually hear, it’s quite revealing taking a spatial average around the ears in a vehicle, it’s a bit of a skill to decipher what to correct and what to ignore, but once you get it right the results can be very awesome! It’s quite the challenge though with reflections and phase issues that can result, driver placement is often needed to be perfect as that’s half the battle

Look up ps sound on you tube to see far more about car audio than I can explain in a small post, he has a pair of fi IBv3 18” woofers in a boot floor cut IB setup, 6” mids and tweeters on the dash and a pair of 8” drivers in sealed enclosures in the front doors, a very good dsp (helix dsp pro 2 the same as me, and excellent amplification from the zapco AP range which I have a 6x150 wrms version on its way to me shortly, they are among the best amplifiers for car purposes and are top tier, if it wasn’t a surf board and me being in the U.K. I’d have it shipped to Amir for testing

I will be doing some testing of various bits of kit I have kicking about for good measure with rew and a preamp I have shortly which I will post
 
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daftcombo

daftcombo

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What is the problem you see with measurements in a small space? One can even put a mic inside a loudspeaker!
Because even moving the mic a few centimeters can reveal very different peaks and dips under 1 kHz. But a head has two ears distant from each other, and there are various ways to sit on a seat, and one can move according to the rhythm... How do you deal with that?

I have done countless measurements in my living room (200 hours of playing with a calibrated Behringer ECM8000, REW and RePhase perhaps), and my corrections and even measurements themselves never were 100% satisfying.

In my small room it was even less consistent. I had to window down to 2ms to have the speakers answer and lost everything certain under 2 kHz or so. As for peaks and dips in the lows, they move according to the placement. When I try to correct that, it sounds awful.
 

Juhazi

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We need to see only below 200Hz to set up subwoofer xo, level and polarity/delay. We typically use 500 or 1000ms gating or RTA measurement. Don't care about wiggles at higher frequencies. Yes modes and interferences are specific to certain spont in space, especially in a small room.

I do both nearfield, semi-nearfield ground plane and listening spot measurements. Semi-nearfield (2 feet) with the sub and main speaker next to each other is best to set xo slopes and timing/delay.

Room response/acoustical measurements are different from a single loudspeaker measurements
https://realtraps.com/art_measuring.htm
http://arqen.com/acoustics-101/acoustic-measurement-primer/
 
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DonH56

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Arguably a sub is more important in a small room since modes are likely to be closer-spaced and deeper than in a larger room with more "stuff". If you can place a subwoofer properly/optimally in the room you should have much flatter bass response.
 

LTig

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So, I have a 3rd system in a very small room (3 m * 2,5 m, that is to say 10ft * 8ft approximatively) for late night chill-out.
It is composed of a Sony DVD player, a JDS Lab Atom used as headphones amp and pre-amp for a pair of JBL 305p mkII.
In this room I mostly listen to piano, but also electronic music at times while browsing this site on my phone (I-F "mixed up in the Hague" for instance).

My question is: would there be any improvement with a JBL 310s subwoofer (or any subwoofer)? As I listen at very moderate volume, wouldn't it be better to have more bass in order to actually hear it?

Cheers.
I think so. I have a pair of Genelc 8020 on my desktop and a Kef PSW2000 I got for a pizza from a former colleague. SQ is better with sub although I have just matched the sub by ear so far (it's fed by the link output of the 8020, and the 8020 is set to 80 Hz highpass). For serious integration I have to use REW and may end up with buying said JBL sub due to its own crossover.
 

DonH56

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Re. room size and wavelength: You cannot establish a full wavelength signal lower than the maximum room dimension but you can certainly emit lower signals from your speakers and they will be heard as they pass by your ears. The measured -3 dB point in my room using my subs is 7 Hz, a wavelength of ~1127/7 = 161 feet, and the largest room dimension is 17' 7". I do have room modes related to that dimension but, after placing the subs and EQ, the response is smooth enough well above and below them.
 

Willem

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The problem with bass in a small room is that the room modes will be at higher frequencies and hence will be more obnoxious. And they will have their harmonics at even higher frequencies. Dealing with them with bass traps is obviously not on, given the small size of the room, and equalizing them is of course possible, but the optimum listening position will be narrower, the higher the equalized frequency. In short, I think adding deep bass in a small room is not a good idea if you hate room modes and woolly slow bass (as I do).
Mind you, this is from someone who likes deep bass, and has a flat in-room response down to 13 Hz in his large main listening room (but only small Harbeth P3ESRs in his study).
 

RayDunzl

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Re. room size and wavelength: You cannot establish a full wavelength signal lower than the maximum room dimension but you can certainly emit lower signals from your speakers and they will be heard as they pass by your ears.

Proven by headphones, no?
 

Juhazi

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