[randog]

I've been looking at DIY sub options to complement my 1801's in both music and HT and am intrigued by DIY Cable's WMD kit for the sealed Tumult. Now this is a massive 15" woofer but in a reasonable enclosure (3 cubic feet).

Is it too much gap to go from the W18 SEAS 7" to a 15" sub? Does it make for poor integration in the 60-100 hz range?

Thanks,
Randog

[David Ellis]

Randy,

My 2c.

The problem is driver resolution and hearing resolution.  

With many speaker systems the transition from subwoofer to midwoofer/monitor is easy because there is "mush" transitioning to "mush".  None of it is very clear so the distortion kinda' gels together - great, no problem!  Unfortunatly this glory ends when a guy gets better ears or better components in one end of his system.

I am not sure which comes first.  Some guys get better ears (i.e. live syphony) , then get better system resolution.  Some guys get better system resolution then get better ears (the symphony).  The discussion is similar to the "chicken or egg" matter.  Nobody really knows which one came first.  However, there is one truth - some guys never eat poultry and have cruddy systems.  For everyone else, keep reading.

The W18 is obviously stiff.

The onset of cone distortion happens very early - much earlier than many might like to confess.  I can hear the difference in cone resolution on 8" woofers around 100hz or lower.  I did a comparison with an old Focal 8" Kevlar driver (very stiff) and an 8" Meniscus Poly woofer.  The motor structure is similar, and actually favors the 8" poly driver.  However, the clarity of bass from the Focal was much cleaner and better to my ears.

I HIGHLY suggest that whatever woofer is used that the cone be VERY stiff.  This can certanly be true in a 15" woofer.  The tell-tale sign of a nice stiff cone is the cone resonance.  With a 15" woofer there should be a nice flume/bubble of resonance around 500hz.  If not, I'd be skeptical about that 15" cone being "stiff".  If you want audio Nirvana in a subwoofer, a stiff cone will be necessary for a perfect match with the 1801.

The 1801 is obviously perfectly capable of use to 60hz.   I think Emilio Provenzano found 80hz was most desirable with his dual SCC300s.

Dave

[EProvenzano]

Hi randog, that's me --->Emilio Provenzano

Dave is correct. After about 4 months of long listening trials I love my system crossed at 80hz. 24db/oct symetrical slopes worked well for me.

I'd like to ask tho...do you plan on using this sub for HT as well as music?
I ask because you will be grossly over doing it with the Tumult driver as far as SPL potential is concerned. Based on my reading and experince with the 1801's, the Tumult has potential to play way louder and be largely under utilized if you plan on blending it seamlessly with 1801's. For music I think you'd be better served with a pair of highly musical subs, like the SCC300's (I'm not implying that the Tumult is not musical, it may very well be).
If the sub needs to serve dual purpose that's another story. I love loud, brute subs for HT as much as the next guy. In that case you can never over do it    


In my experience two 12" subs, with decent xmax, will get you all the output you need when paired with 1801's.

Good luck.
EP

[randog]

Hi Emilio,

Yes, I wouldn't be considering the Tumult if it was 2-channel only. My setup is for both 2-channel and HT and I would like a sub that works for both. I understand that is a tall order and I don't want to compromise either if that is possible. When Kevin of DIY came out with this small sealed sub kit for a Tumult and is advertising it as a musical solution, I started wondering if this could be the answer... still am.  

Dave, thanks for your input. It looks like I have some more homework to see what sub driver will integrate best based on your input about stiffness, etc. It makes sense. What I do know is that I'd prefer the cabinet not be any larger than 3 cubic feet internal volume. Perhaps if I can satisfy both criteria, I'll have found my answer.

Randy

I forgot to mention... I'd also like a single box solution... at least for now.

[dayneger]

Randy,

How about Kevin's new mini WMD?  14" cubes with the output of a Rava, based on a 10" driver using the XBL^2 motor and 18mm one-way excursion.  I was just asking Dave about this driver in the 10" on the bottom link.  This would make a great stereo pair with enough output for most situations (or any that I can conceive of in a normal house with non-concert-destroyed hearing  ) for approximately the same price as a Tumult kit.

Whether they're stiff enough for the 1801s, ?

Dayne

[David Ellis]

I haven't mentioned my thoughts on a few other things.  Here seems applicable.

First, dual subwoofers can integrate quite nice IMO.  A single can work well too, but only when positioned dead center.  Offset single subs just don't work for my ears.  The soundstage is eschewed.

Second, those seeking that serious HT rumbling drone from a subwoofer should not implement the SCC300.  Sure, the low frequency spl is present, but not overpowering.  In my room, I thought it provided a darn near perfect balance with NO plate amp equalization/boost.  The bombs in the movie Pearl Harbor were perfect.  I actually removed the boost from my Apex Sr. plate amp and preferred this sound.  With the boost installed there was too much boom.  Home theater guys like this boom .  I don't.

This was my experience in my room.

More recently, a very well respected pair of ears didn't think the SCC300 had enough low frequncy spl - Jack Giuffre's ears.  I repect Jack's input on the matter, and look forward to the next driver Jack implements in his subwoofer.  I hope Jack will post some comments here.

Getting the perfect subwoofer spl is like trying to nail Jello to a wall.  There are sooooo many room factors.  I'd rather have it a 2-3db down in the 20-30hz zone than 2-3db up.  There ain't much program material down there and I'd rather have it in the backround than overpronounced.

[rosconey]

dave you should find a vmps large for a listen
i think you would like it

[David Ellis]

dave you should find a vmps large for a listen
i think you would like it

Why?

By doing this would I better understand what 2 dogs might do with 4 monkeys?

[rosconey]

you can pick on me but the dogs and monkey's are off limits

[rosconey]

sounds like the vmps meets your expectations from a sub is all.
2 drivers-stiff cones-(NO plate amp equalization/boost),has a adjustable pr
thats all

[randog]

Let's talk a little more about the SCC300 then...

It looks like it needs a large cabinet, right? Somewhere around 4 cubic feet?

Speaking of WAF, I don't have a lot of space so I think 2 cabinets this large is out of the question. Also, I have an armoire between the speakers so centering the sub ain't gonna work either. Finally, the HT preamp I just ordered only has a mono sub out. If I want stereo, do I give up anything by wiring the subs up the old-fashioned way (high-level from the speaker posts)? Are all modern sub amps setup to allow for either?

If I go stereo, the cabinet sizes need to be very unobtrusive.

I've been dinking around with these ideas for a year now and it is still more important to me for a sub(s) that is musical and blends well with the 1801's. For HT, I need some bottom end to compliment the 1801's. I know the droning you speak of Dave and I'm also not a big fan of it, either. I do like much more bass than the 1801's are providing for me, however.

My 1801's are pulled out in front of the armoire, so imaging doesn't seem to be much of an issue (in case you are wondering). I have my house on CAD, so maybe I'll do a screenshot and you guys can help me decide type of sub and placement best guesses from the getgo.

The HT receiver I'll be using is the Panasonic XR-45. The reviews it is getting for amplification sonics is incredible (I know Jack's heard it). Anyway, it was a no-brainer for me since I needed a newer processor anyway and it is dirt cheap. The problem with that is it is limited in feature-set (mono sub out, no pre outs, etc). I will either go full digital, or I'll have to make a DIY high-quality speaker selector box to use the 1801's with digital HT and analog 2-channel both. The benefit that I didn't have before is the amplification will now be the same to all my HT speakers. In either case, in order to use the sub(s) for both HT and 2-channel, I think they would require high-level attachment... so I'm really interested in feedback on that. I know REL designs their subs to be connected that way as the preferred method.

Obviously my setup and space considerations are quite specific and if not carefully planned, I could be making some very expensive mistakes.

Randy

[David Ellis]

I don't know much about his specific drivers.  They might be good and stiff.  I really don't know.  I looked for his stuff at CES 2002, but couldn't find it?

His PR setup pretty slick.  Changing the "impedance" of the PR can be done simply by adding/removing weight.  This is essentially the same as making a port longer or shorter.  

The downside is the roll off below the tuning frequeny will still be 24db octave.  This is nowhere near ideal when coupling with the lift of most rooms.

Further, the system damping on the driver will be darn similar to a ported system.  The system will be underdamped with a Q over 1.

Hey, I have a question for you.  I think that Brian Cheney is now using the Sonicap.  Is this true?

Dave

[JoshK]

I think I remember Big B saying the tuning frequency was 16 cycles.  If so then 24 db/oct below that isn't a big deal.  

[rosconey]

dont know what he uses for crossover parts yet-i got my large without crossover because my reciever has a lfe, but i'm setting up a 2 channel room(with the 4 monkey's) and will be getting 2 crossovers from him soon.
the monkeys are odyssey mono's, on the mexican web page the word mono gets goofed up in tranlation

[David Ellis]

If the tuning frequency is 16hz then it's probably too flat above this for my taste.  Flat to 20hz results in boom in room due to coupling.  IME the 12db sealed slope works wonderfully.

This is my experience and preference though.  I am certainly not in the BIG BOOMY bass category.  I like mine nicely balanced and crisp.  

Dave

[rosconey]

no boom here
i'm far from a speaker builder,but  i do know solid fast bass and boom.

[David Ellis]

I am very sorry that I missed your query until now.

I was probably writing a post, then missed yours in the mix.

Anyhow,

Yes, the SCC300 is good in 3-4 cubic feet.  The latter will provide a slightly shallower slope and lower Q bass enclosure (overdamped).  Many find this desirable.  No matter how you dice the SCC300, it'll need a big cabinet.

If you are wanting something different/smaller, I'd like to see what Jack Giuffre arrives at.  He recently mentioned trying a different driver.  I think it was one of the Adire units, but am not 100% confident.  You might post a query for Jacks response on the subwoofer issue.  I trust Jack's ears, and he has a pair of 1801s.  

I suppose you could just email Jack too.

Dave

[randog]

Who's done the SCC300 in 3 cubic feet? Anyone know what the Q is for 3 and 4 cubic feet?

Randy

[jackman]

Hi guys,

Great thread.  I'm a bit of a novice in the subwoofer department.  I owned a SCC300 for a while (sold to Al Garay) but I decided to make a change because I wanted something with more low end output for HT.  For a music-only system, I don't think you can do better than the SCC300 ("better" meaning more articulate bass).  I was going to get a Tumult or a DPL12 or a number of 15" subs I looked at, but wound up getting a 12" Partsexpress Titanic MKII because it looked like a good match for my subwoofer goals (plus it was on sale and the price was very good).   I can't comment on the sound because I still haven't disabled the +6dB boost in my Apex Sr. amp.  With the boost, all drivers go "boom boom".  I can't say the new driver sounds better than the SCC300 because the boost is screwing everything up.  

I like the sound of the 1801's without the subwoofer.  This could partly be due to the boost I have on my sub.  I think it's also due to the fact that the 1801's have decent bass and my placement options on the sub make integration difficult.  i was thinking about getting a "Feedback Destroyer" or similar, but I don't know if I want to mess around with subwoofer integration for music.  

Will report back after I have a chance to disable to boost.  It shouldn't take very long.  I also have to install some higher value caps in my sub amp, they are still in the bag calling out to me along with my soldering iron.  Heck, I may just retire the sub to a HT and spend my time and energy (and $$$) on room treatments and a dedicated 20 amp line.   The sub (and Bass Shakers!) WILL be put to good use when playing X-Box, my latest obsession.  

Sorry my response wasn't more helpful.  

Jack

[spectralman]

Sorry if I'm taking this post a little off course, but who makes the SCC300 subwoofer and where can I find some info. on it?  Thanks.

Bill