My in room response of two 12 inch SEAS lotus subwoofers in sealed enclosures.

T

Thegenuinearticle

Enthusiast
I always thought my subwoofer performance was pretty excellent. So much so that I never really bothered or worried about seeing what the result was on a graph. I built the enclosures with in mind of having close to optimum QTC at 0.75 and had theoretically an F3 of around 32 HZ, but I have always been really surprised at how much low extension I get from my subs in the low 20 HZ regions with movies and other content.

So I decided to break out the ominimic and REW just to see how my perception of excellent bass stacked up to a measurement. It really starts to make sense why I thought these subwoofers sounded and felt amazing. Flat from 18 HZ to 50 HZ. Some other people have been skeptical regarding this result, but I assure you its completely authentic. No smoothing or EQ has been used for this measurement and the filters in my miniDSP have been turned off. I swept REW from 15-100 HZ. I typically cross the subs over LPF @40 HZ 24db to meet my towers which are played full range. For a room this size in my opinion (11x14) its not necessary to high pass a pair of capable towers at 80 hz. Not bad for a pair of 12 year old subs originally intended for automotive use...Thanks for viewing..
 

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Verdinut

Verdinut

Audioholic Spartan
In my opinion, that rather uniform response down to 20 Hz would be the result from room gain.
 
T

Thegenuinearticle

Enthusiast
In my opinion, that rather uniform response down to 20 Hz would be the result from room gain.
Without a doubt room gain is at work here but who would argue that its clearly not advantageous in this circumstance? Take these two subs and put them in another room or for that matter when I measure them individually and the result is quite a bit different. With the placement in this room and using the two subs to combat modes its a result that is quite impressive.
 
T

Thegenuinearticle

Enthusiast
That is fantastic response with no Eq!!
I know right? I've had some haters try and tell me its a faulty measurement because even with EQ , time alignment, phase, and other processing their response looks worse than an irregular heartbeat but thats their problem and clearly not mine...lol...Before this measurement while watching movies when some infrasonic or close to it content would be reproduced I would just grin in surprise as to how smooth and deep these things get in this room. Its actually pretty wicked...
 
Pogre

Pogre

Audioholic Slumlord
Without a doubt room gain is at work here but who would argue that its clearly not advantageous in this circumstance? Take these two subs and put them in another room or for that matter when I measure them individually and the result is quite a bit different. With the placement in this room and using the two subs to combat modes its a result that is quite impressive.
That is impressive with no eq and smart placement to take advantage of their strengths.

You don't think a strategically place pair of 12" ported subs could do just as well, or even extend deeper, and at higher SPL?

I have a pair of ported 15s and managed pretty flat from 115 hz to about 15 hz.

04-05-20 Final-600x232.jpg
04-05-20 Waterfall-600x262.jpg


Apples and oranges tho. I'm in a huge room and have larger subs, plus there's some eq'ing in there too. I have some noise below 20 hz but that's at the edge of human hearing and none of my music has content that deep anyway. Well, maybe a couple of demo cds (including some pipe organ!) I like to play from time to time for shits n giggles or to show off. :p
 
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Verdinut

Verdinut

Audioholic Spartan
That is impressive with no eq and smart placement to take advantage of their strengths.

You don't think a strategically place pair of 12" ported subs could do just as well, or even extend deeper?

I have a pair of ported 15s and managed pretty flat from 115 hz to about 15 hz.

View attachment 35825View attachment 35824

Apples and oranges tho. I'm in a huge room and have larger subs, plus there's some eq'ing in there too. I have some noise below 20 hz but that's at the edge of human hearing and none of my music has content that deep anyway. Well, maybe a couple of demo cds (including some pipe organ!) I like to play from time to time for shits n giggles or to show off. :p
You obtained that response using the Audyssey MultiEQ Editor app? That's quite fantastic.
 
Pogre

Pogre

Audioholic Slumlord
Those are some very nice looking subs I must say. I wouldn't be upset if I owned them. I've only recently heard a Seas woofer (6" custom built for Ascend Acoustics in my ported ( :p ) Sierra 2s) and I know in that cabinet it's amazing. I can't believe the bass this little 6" driver can put out in my large room.

You already touched on it. You need the right driver in the right cabinet, first and foremost, then you need to figure out if you have any size constraints and SPL goals. If there are no size constraints, I would always go ported.
 
Pogre

Pogre

Audioholic Slumlord
You obtained that response using the Audyssey MultiEQ Editor app? That's quite fantastic.
Not the app. XT32 got me most of the way there then I took sweeps and made a few adjustments with a MiniDSP 2x4 HD. I do think I might be able to do that with the editor alone tho. I've only recently started experiment with it. I know @PENG was able to get good enough results to put his mini away. Next time I have the time I'm gonna experiment some more. Watch for future posts!
 
T

Thegenuinearticle

Enthusiast
That is impressive with no eq and smart placement to take advantage of their strengths.

You don't think a strategically place pair of 12" ported subs could do just as well, or even extend deeper, and at higher SPL?

I have a pair of ported 15s and managed pretty flat from 115 hz to about 15 hz.

View attachment 35825View attachment 35824

Apples and oranges tho. I'm in a huge room and have larger subs, plus there's some eq'ing in there too. I have some noise below 20 hz but that's at the edge of human hearing and none of my music has content that deep anyway. Well, maybe a couple of demo cds (including some pipe organ!) I like to play from time to time for shits n giggles or to show off. :p
Thats an impressive result you have there as well. Regarding the prospect of the drivers being in a ported enclosure, these subs were originally built for automotive use and have some rather strange parameters for being designed for that use. SEAS recommended around 1.00- 1.5 cubic feet sealed which when modeled comes to around 0.9 -1.0 QTC. For a 12 inch driver to obtain a QTC of .707 these model at 3.5 cubic feet which is quite large for a 12 inch. I struck a compromise of 2.85 cubic feet and theoretically am T a QTC of 0.75 so its still far better than what the manufacturer suggests for their automotive use. My only guess is that their intention was to have a bump or emphasis around 40 HZ in xar because that's how these subs sound in that small if an enclosure ( very colored and not very linear).
If I were to use them ported they model at an even larger enclosure at around 7 cubic feet each...lol

Yes I could do two ported subs and get more extension but the subs I would choose to use (Scanspeak Discovery 30) ask for roughly 3.5-3.8 cubic feet at a tuning of 19 HZ. Its already a small room and these sealed enclosures are none the less still kind of big. BTW I use the Scanspeak subs in my car setup in a dual chambered sealed box I made at around 1.48 cubic feet per chamber. The Scanspeak discovery 30 is an awesome driver for the money. Super low resonant frequency (17 HZ) with good efficiency. A very musical no nonsense driver.

Thanks for the nice words and appreciate the feedback...
 

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T

Thegenuinearticle

Enthusiast
Those are some very nice looking subs I must say. I wouldn't be upset if I owned them. I've only recently heard a Seas woofer (6" custom built for Ascend Acoustics in my ported ( :p ) Sierra 2s) and I know in that cabinet it's amazing. I can't believe the bass this little 6" driver can put out in my large room.

You already touched on it. You need the right driver in the right cabinet, first and foremost, then you need to figure out if you have any size constraints and SPL goals. If there are no size constraints, I would always go ported.
Hey thanks for the compliment on the subs. I made the floor standers and media stand as well. I've got a build log on here about the floor standers. Yes SEAS are a very well respected build house. I like Scanspeak as well and have a car setup that uses all Scanspeak drivers. Maybe some time I will post up the pictures here of that install and fabrication steps.
 

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lovinthehd

lovinthehd

Audioholic Jedi
Nice! What did those drivers cost? Suspect that now that SEAS has withdrawn from the diy market mostly not available now?
 
T

Thegenuinearticle

Enthusiast
Nice! What did those drivers cost? Suspect that now that SEAS has withdrawn from the diy market mostly not available now?
SEAS has not withdrawn from the DIY market. Its their bread and butter actually. Madisound.com is still the main distributor in the US for their raw drivers. These 12 inch subs are no longer available so they are something rare. I think I may have paid around $300-$500 each for them around 2007. They have a 10 inch sub available today that is built quite well and has displayed good test results....Thanks for commenting.
 
Verdinut

Verdinut

Audioholic Spartan
SEAS has not withdrawn from the DIY market. Its their bread and butter actually. Madisound.com is still the main distributor in the US for their raw drivers. These 12 inch subs are no longer available so they are something rare. I think I may have paid around $300-$500 each for them around 2007. They have a 10 inch sub available today that is built quite well and has displayed good test results....Thanks for commenting.
Solen, the renowned inductor and crossover capacitor manufacturer in St-Hubert, Quebec also carries the Seas line of raw drivers and even some of their kits:

 
T

Thegenuinearticle

Enthusiast
Solen, the renowned inductor and crossover capacitor manufacturer in St-Hubert, Quebec also carries the Seas line of raw drivers and even some of their kits:

Yep Solen has been around a long time as well. Good capacitors also! Slightly off subject but I actually remember a time when Focal/ JMlab sold their drivers for home use individually if people wanted to use them through these distributors.You can now only buy their car drivers in this way though and not the home drivers.
 
Verdinut

Verdinut

Audioholic Spartan
Yep Solen has been around a long time as well. Good capacitors also! Slightly off subject but I actually remember a time when Focal/ JMlab sold their drivers for home use individually if people wanted to use them through these distributors.You can now only buy their car drivers in this way though and not the home drivers.
Yeah, Solen was founded many years ago. I knew very well the ex president, Denis Ouellet, who passed away several years ago. His son, Christian, now runs the business which I believe was founded by the grandfather, who had built the machine to precisely coil the air core inductors.
 
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