The right sub enclosure for home studio use?

[hatrix 2]

I have a small home studio which I use to produce music and also DJ. Obviously SQ is really my only concern.

 

My studio's audio setup consists of the following components (in the spoler):

FiiO E17 USB DAC

Mackie MR5MKII Active Monitors

Sundown Audio E8v3 in a 0.76 cuft net ported box tuned to 33hz using a single aero port (rear firing, sub up)

Behringer Eurorack MX 2642A 26 input 4-bus mixing console

Soundstorm Rave r380.2 amp, powering the E8v3 bridged @ 4 ohms (very old amp but it provides plenty of power to the E8v3 and sounds great)

AKG K240s headphones

Some acoustic paneling on the wall behind my desk and monitors (but not anywhere near the amount I really want)

 

In case anyone is wondering, audio path is as follows: E17 is my DAC via USB outputting at 24bit/96k using the line out accessory (lo bypass enabled, so volume control and EQ settings don't affect the line out signal from the DAC), line out runs into a stereo input on my mixing console. Control room outputs go to my monitors, while group 1 and 2 outputs connect to the Soundstorm amp. Faders are set to unity (0dB) and gain for the stereo input is adjusted accordingly depending on the program I'm using (for example, I have Traktor set to output at -10dB, so the gain on my mixer is increased to achieve ~0dB peaks)

 

Anyways, back on topic... I've been reading more in depth on other types of sub enclosures/designs such as IB. My priority in design is SQ. SPL is not much of a concern. An IB setup almost seems like the perfect studio subwoofer design on paper. Assuming it's correctly done, near flat frequency response, extremely low distortion, great transient response.... At least that's what I gathered from reading, but with the difficulty involved in properly designing a true IB setup, it might not be worth the effort.

 

When I look at active studio subwoofers though, just about every design seems to be ported.

 

My current setup with the E8v3 is very clean sounding and blends very well with my monitors. I'm very pleased with it. It gets VERY loud for being a single 8" woofer (enough to rattle the walls in my house with ease), and it extends very low. I don't hear any noticeable drop in output until under 35hz.

 

Now if I'm pleased with my current setup, you may ask why try to change it ? Well normally I wouldn't bother, but I have an SA-15 D2 sitting in my room unused and was wondering if it could offer better SQ than my current setup, and if so what box design would be ideal for my goal ? Sealed doesn't seem like a very good option considering the FS of the driver. Also, I'm a bit clueless when it comes to bandpass designs.

Edited January 5, 2014 by hatrix

[REVpuggie 23]

I like building wacky disigns so I'd probably build a series tuned bandpass ,the most sensible thing to do is probably a closed box  to avoid phasing problems and a good dsp to extend the lows .

[hatrix 2]

I like building wacky disigns so I'd probably build a series tuned bandpass ,the most sensible thing to do is probably a closed box  to avoid phasing problems and a good dsp to extend the lows .

 

Yea that's the thing about going sealed though... I know I'll need an EQ boost on the lows because of how high FS is.

 

My mixer is capable of EQing without having to buy a DSP and add more processing to the audio chain, but it's low band is at 80hz...

 

Going from a ported E8v3 to a sealed SA-15... I'm really curious what difference in output I would see. SQ wise I'm really not sure how much better it would sound.

Edited January 5, 2014 by hatrix

[REVpuggie 23]

If you're that curious than building a closed box for the SA shoulnt  be that much trouble.

[hatrix 2]

If you're that curious than building a closed box for the SA shoulnt  be that much trouble.

 

I agree, but if I don't like how it sounds I'll be wasting money on MDF....

 

So a sealed enclosure should provide better SQ, right ?

 

I'd like to find out if anyone has experience with both drivers, or any driver from both E and SA series, and can comment on SQ differences between the two. Then I can determine which driver to choose for a sealed enclosure and go from there.

 

In general, is there any difference in SQ between different size drivers ?

[lithium 358]

I like building wacky disigns so I'd probably build a series tuned bandpass ,the most sensible thing to do is probably a closed box  to avoid phasing problems and a good dsp to extend the lows .

 

that sounds ridiculous. dsp for what? boosting the low end because you designed a shitty enclosure? 

[hatrix 2]

I like building wacky disigns so I'd probably build a series tuned bandpass ,the most sensible thing to do is probably a closed box  to avoid phasing problems and a good dsp to extend the lows .

 

that sounds ridiculous. dsp for what? boosting the low end because you designed a shitty enclosure? 

 

Would I be loosing SQ by going above the recommend 2.5 cubes for a sealed enclosure for an SA-15 ? Will going bigger provide better low end extension ?

 

Note I'll probably only be running 300-400 watts to the sub, if that.

[lithium 358]

i dont know did you model it? why sealed? what do you mean by SQ? 

 

try modeling other subs, maybe some designed for the home environment. remember car audio takes advantage of cabin gain and other factors (so its probably best to ignore many of the recommended enclosure sizes), home audio is a different animal. 

Edited January 5, 2014 by lithium

[hatrix 2]

No I haven't, I will though.

 

I'm not certain on sealed yet. It was just a thought as I've never built a sealed enclosure. By SQ I mean a near flat frequency response down to 30hz or so (upper cut off can be lower than 80hz, my monitors play surprisingly low) with very low or no audible distortion, good transients.

Edited January 5, 2014 by hatrix

[95Honda 486]

I haven't modeled the subwoofer, so I cannot comment on that particular driver, BUT, here are a few things you can be certain about:

 

- You are dealing with music that you want to hear accurately.  This isn't going to be a time to experiment with complicated enclosures like a band-pass, you don't want to start changing your music because your playback system isn't linear.  I wouldn't mess with a transmission line either, they need to have the stuffing adjusted for response.  And I am not saying that these enclosures can't be linear, they are just harder to get to that point. 

 

- Build something that can be predictably modeled.  Easiest is a sealed box, second easy would be 4th order vented.  The sealed box is easy, I would just shoot for a Q of .7, that is nice and flat and will give you the most neutral output signature.  If you were happy with the 8" ported, the 15 sealed will give you enough output.  If you go 4th order, design for a flat response, no ripple and tune somewhere below 30Hz.  The important part will be designing for no ripple.  If you have even a few db of ripple the room may exaggerate it and you make change your music to compensate, exactly what you want to avoid.

 

- When you build the cabinets make them solid.  If you can only use 3/4" MDF you need to brace well.  You need to stay conservative with the cabinet designs, not a time to experiment with weird shapes.  Make sure you joints are tight and well sealed, any little variance in enclosure tolerances is going to result in annoying rattles and noises.  If you use some type of material to make your vents other than wood, use a glue to bond them wherever they touch wood, and make sure it is a glue that isn't rock hard.

 

I have build many subwoofer system for home audio systems, probably a hundred or so since the early 90's...  The ones that have sounded the best were the ones that I built sticking to some of these guidelines.  I have build more complicated designs, but I couldn't always get them right the first time.  The sealed alignments and almost all of the 4th order alignments always turned out the way I modeled, if I built them right...

 

Simple design, solid cabinets, and good room placement will be key... 

[Quentin Jarrell 671]

I suggest ^ and buy the 7th edition version of the cookbook. It will explain in detail of how to go about building to a desired response and Q. And how to measure, tune, and adjust if need be.

I personally wouldn't build a BP enclosure for a sub stage intended on playing the full sub stage. The transient response on a BP enclosure with a large passband will have a much degraded transient response compared to a ported box. Again this is explained in the cookbook.

[Impious 1,476]

 

In general, is there any difference in SQ between different size drivers ?

All things equal for a given output level the larger driver will have lower distortion since it will have less excursion for a given output level.

[hatrix 2]

Thanks for the help guys, I really appreciate it.

 

This is the SA-15 modeled in WinISD using a vented enclosure (single aero port) that is 4 cubes tuned to 28hz (seemed to offer the flattest response):

 

 

Modeling a sealed enclosure yields pretty poor results. Seems no matter the enclosure size, it slopes hard around 50hz. WinISD doesn't recommend using sealed or a 4th order from what I've tested. Either ported or 6th order.

Edited January 5, 2014 by hatrix

[95Honda 486]

Post the T/S parameters you are using...

[hatrix 2]

I used the ones provided on the Sundown site.

 

http://www.sundownaudio.com/misc/woofer_measurements/SA_Series_Manual%2810-12-15%29.pdf

[95Honda 486]

The driver has a fairly high Q.  You are going to get a bump in response vented, post up your sealed graph... 

[hatrix 2]

The driver has a fairly high Q.  You are going to get a bump in response vented, post up your sealed graph... 

 

I'm sure it could be tamed with EQ if I decided to go vented... Either with my mixer or through an old Technics hardware EQ I have sitting around (7 bands for both the left and right channel).

 

I'm not really sure what size I should go for with a sealed enclosure, so I just went with the suggestion on Sundown's site. The main frequencies I care about are basically where it starts to slope. Below ~30hz, not very important to me, but 30-60hz is very crucial when it comes to the music I produce.

 

Edited January 6, 2014 by hatrix

[Impious 1,476]

Keep in mind that rooms experience a "cabin gain" similar to what we experience in car audio, although not quite to the same extreme it exists none the less. There are some calculators out there that can help you predict this as it's based on the dimensions of your listening environment and placement of the subwoofer. Just the same as car audio, the response WinISD predicts will not be the same as you experience in your room. Without knowing the room gain you experience it'll be hard to design an enclosure with flat in-room response.

I would check out Jeff's room gain calculator and see if you can get some idea for how the room behaves before you make any decision based on a WinISD modeled curve: http://audio.claub.net/software/jbabgy/jbagby.html

[///M5 2,833]

Every studio I've worked with we've measured in situ and the designs were then adjusted. This means an iteration in your box and some measurement gear, but it'll really help nail things down. Be a rather good learning experience too. We've always taken it a step further though and done room corrections, but that requires measurement gear that is extremely cost prohibitive.

[hatrix 2]

Keep in mind that rooms experience a "cabin gain" similar to what we experience in car audio, although not quite to the same extreme it exists none the less. There are some calculators out there that can help you predict this as it's based on the dimensions of your listening environment and placement of the subwoofer. Just the same as car audio, the response WinISD predicts will not be the same as you experience in your room. Without knowing the room gain you experience it'll be hard to design an enclosure with flat in-room response.

I would check out Jeff's room gain calculator and see if you can get some idea for how the room behaves before you make any decision based on a WinISD modeled curve: http://audio.claub.net/software/jbabgy/jbagby.html

 

Yea I know there's some cabin gain from my room. As of right now my E8v3 has it's aero port fired right into a corner of my studio room. Obviously not ideal at all for a flat response, but lately it's only been used for listening to music. Someone else who lives in my house happens to work really dumb hours at night so they are usually asleep all day, and having the sub on at ALL makes it audible anywhere in the house pretty much.

 

Thanks for the link, I was wondering if there was a tool to calculate in my room measurements also.

 

Every studio I've worked with we've measured in situ and the designs were then adjusted. This means an iteration in your box and some measurement gear, but it'll really help nail things down. Be a rather good learning experience too. We've always taken it a step further though and done room corrections, but that requires measurement gear that is extremely cost prohibitive.

 

Oh man, if I could afford measurement mics I totally would run TruRTA and get some ideas on how my actual frequency response is.

 

I can only dream of having an actual studio with its own building and properly designed room. I wish acoustic treatment wasn't so damn expensive. Way more money than most of my audio hardware combined.

 

I'd like to learn more about proper acoustic treatment in studio environments. I have done a fair share of reading, but completely taming a room is such a hard task.

 

With most of us being used to the more "boomy" output of our sub setups in vehicles, it's so much different in a studio setup.

Edited January 6, 2014 by hatrix

[///M5 2,833]

Working for and having a full catalog of Bruel & Kjaer gear along with a Physics/Acoustics degree has a tendency to have people beg you to come help. I've done a lot of measurements in really interesting rooms. From amazing speaker designers, musicians, and industrial test facilities there is some neat shit done with acoustics by humans.

[95Honda 486]

The room, as implied by M5 and Impious, is hugely responsible for the end response.

 

If you aren't going to get the gear to measure and correct, I would build the sealed box first.  That response will probably be really flat in your room. 

 

It is also really easy to get that sealed box right.

 

You need some type of correction to get flat response, especially at certain listening positions, it is best to have a design that requires the least amount of correction to get there...

[joe79 9]

http://www.powersoundaudio.com/

 

 

I have been interested in seeing these in action. 

[lithium 358]

http://www.powersoundaudio.com/

 

 

I have been interested in seeing these in action. 

why's that? 

[95Honda 486]

^^ That is a good example of why DIY is the way to go...  For almost $3K you can build a set of subwoofers with amplification that is beyond insane...

 

Hell, my pair of XXX18s, 5Kw RMS of power + processing and cabinets was only $2K...