Rhythmik Audio DirectServo Subs

[mixadude]

Anybody here use these? Waddaya think?

I just ordered 2 of these DS-350 (http://www.rythmikaudio.com/servo_product.htm) 12" speaker/servo-amp jobs. Now to make the boxes!

[Geoffcin]

Anybody here use these? Waddaya think?

I just ordered 2 of these DS-350 (http://www.rythmikaudio.com/servo_product.htm) 12" speaker/servo-amp jobs. Now to make the boxes!

Before I bought my subs. I called to get more info from the manufacturer, and got a really informative chat about sub design, and servo tech. I'm glad to see that Brian is doing well with these subs. Probably the best sub kit out there for the $$$.

[kexodusc]

I hope you're going sealed. If you have access to Dado blades when cutting the boxes, rabbets or mitre joints will go a long way towards mitigating air-leaks.
These were a very close second when I built my sub last month. I haven't heard a bad thing about them yet. I'm sure 2 of them will make you very popular with your neighbors.

[mixadude]

Thanks for the replies... Sorry for the delay, I've been quite busy...

I just picked up the speakers and amps from Brian this morning. Nice guy :D

The speakers are pretty impressive; big cast frames with large magnet assemblies and a heavy rubber surround, aluminum cones, all very stiff and stable. Looks like a 2.5" vc former and a very long throw. The tensile leads are interesting... they're glued to the spider so the flexing is minimal, and there's no chance of a tensile flapping against the cone (actually more like an inverted dome). He's using a molex connector for the 4 wire hookup to the speaker.

Yeah, sealed 2 cubic foot boxes is what Brian recommends, so that's it then, maybe out of 1" MDF. Don't know if I'll dado, but they'll definitely be airtight and solid. My friend that I built over 300 (matched-passive) crossovers for, sold the saws and the whole shop, so I may have somebody else do it. I don't have adequate facilities here.

I may coat them with Linex, the truck bed liner stuff. We used it on our PA cabinets. Not really pretty, but I don't care that much; the boxes are small and will be hidden under shelving. It does, though, absolutely seal the joints and wood. It also collects dust and is hard to wipe off... maybe I'll put a doillie on 'em, LOL

edit- BTW I picked up 4 pounds of Dacron at Speaker City on the way home to stuff in em. Any opinions on that?

[mixadude]

On further reflection, I'm thinkin I might just like to build these with my dad... he's 70 and an accomplished cabinet maker (among many other mutual interests, he was a music teacher during all of my schoolyears and childhood), you know... no screws or nails kinda guy... "screws are for hinges". ..I'm thinkin I need to go see him (he's only 500 miles from here) and we'll fire up the old woodshop :D

Dados and rabbets, mitre joints, and dovetails will be the order of the day :D

Maybe I'll vernier em with one of our "old" trees. Forget the Linex, it won't be required ;)

[mixadude]

Hi everybody,

Well, my enclosures ended up being built by Brad at Woodstyle Products. He (they) did a great job, all outa 1" MDF, with a black laquer finish, with a ~2.1 cu ft internal as specified, mitred joints and extremely clean cuts. He took on the job and delivered the finished product ahead of schedule. Just because certain resellers (several of the DIY kit sites) profess to sell Woodstyle, don't think that they (Woodstyle) can't furnish a better product than what's on those resellers websites or catalogs. Brad was very accomodating, and I consider him and his company a valuabe resource for my future endeavours. If'n you can design it and give a drawing, they can build it. Thanks Brad and staff for a job well done. :D If you need a number for Brad, pm me or google it.

As for the sound of these venerable subs, let me say they won't be gaining the THX logo anytime soon IMO. BUT!!!! They absolutely deliver the bottom 2 octaves for someone with a system capable of 40Hz!!! Egad, I'm so impressed... and they fit sonically wiv my main L/Rs perfectly! (you can prolly feel the earth move from here). With a pair of them and their amps wide open, the settings at 14Hz, Max Damping, and the highest xover point (my Pioneer vsx59 txi does the rest) I run them at -8dB or so usually. Music and HT both are very impressive. But what do I know? :D

Just thought I'd throw this out here. Peace and enjoy :D

[macebanyon]

Hello Mixadude,

I am getting ready to build one of these myself, incorporated into a 2channel music only system. Could you be a little more specific about the SQ of this sub for music?
Thanks

[mixadude]

SQ?

I'm still messin around with them. I have limitted options for placement, but when I finally put them where I intended (center of the front wall both cabinets together) the 80Hz came up to where I thought it should be, but there was a huge bump around 35Hz. So I went over to Guitar Center yesterday and picked up a BFD, and roughed in a filter at about 35 and presto everything sounds much better. I'm guessin here but I'll analize it all later with Smaart.

I've played various genres of music through them. They rock and are solid. I also play the HT, but that part of the system isn't really finished. I'm sure they'll be fine for that as well.

[Geoffcin]

SQ?

I'm still messin around with them. I have limitted options for placement, but when I finally put them where I intended (center of the front wall both cabinets together) the 80Hz came up to where I thought it should be, but there was a huge bump around 35Hz. So I went over to Guitar Center yesterday and picked up a BFD, and roughed in a filter at about 35 and presto everything sounds much better. I'm guessin here but I'll analize it all later with Smaart.

I've played various genres of music through them. They rock and are solid. I also play the HT, but that part of the system isn't really finished. I'm sure they'll be fine for that as well.

Now I'm going to have to get one of these BFDs after both you and Kexo have had such good luck with them.

[kexodusc]

Now I'm going to have to get one of these BFDs after both you and Kexo have had such good luck with them.

Quite honestly, I'm surprised a guy with two 15" Velo's doesn't already have a BFD. If you can tame just one peak it's worth it.

You wouldn't own a speaker that measured +/- 7 dB (or in my case +/- 12 dB), why lower your standards for a sub?

Time to cash in them beer bottles...

[Geoffcin]

Quite honestly, I'm surprised a guy with two 15" Velo's doesn't already have a BFD. If you can tame just one peak it's worth it.

You wouldn't own a speaker that measured +/- 7 dB (or in my case +/- 12 dB), why lower your standards for a sub?

Time to cash in them beer bottles...

Most of the time with audio the subs sit, mostly silently. With the Maggies they really don't get much use, as I'm crossing over at 40hz., but HT is a TOTALLY different matter. For LFE I was able to get +/-5dB across most of the room just by moving them around.

How much loose change does it take to get one of these BFDs?

[kexodusc]

Only $100 plus shipping, maybe $115.

I was like you too...lower crossover down at 60 or 40 Hz..I couldn't decide what I liked better and after looking at my plot, you can probably see why I flip-flopped.
Problem is, even my speaker suffered from room acoustics, and I definitely found it much better to flatten the curve as much as possible all the way up to 80 Hz. Some people go higher than that, I don't think I'll bother, though I do have one minor peak I could tame. Maybe when the 2nd sub is done and these are running stereo.

[mixadude]

Now I'm going to have to get one of these BFDs after both you and Kexo have had such good luck with them.After I read about Kexo and others using it, I thought well that's brilliant, a really cheap but acceptable parametric EQ!

When I do PA I always EQ the subs, there's always at least one resonance that I pull out. Once I get the analizer going, I'm sure it'll get even better. I also set my xover point back up to 80 once I got rid of that ringer.

The Behringer Feedback Destroyer was $108 out the door at Guitar Center. It's a little convoluted to use, but not too bad. ;)


Edit - I just figgured out the drivers in the kit are made by TC Sounds! They look like this (http://www.tcsounds.com/TC2_12_2576.htm) but have the extra windings for the servo feedback

[mixadude]

After a about a month of living with these I'm very happy. The SQ is excellent. I've discovered i can actually hear below 20Hz. Well... actually... I'm in So Cal, and I've been awakened by what I thought was an earthquake... twas the subs making the bed jump up and down ;)

I have em set to max damping and max extension (14Hz), and of course the BFD set via Smaart Live v4.5.

My mixa bud that came to hear em said "wow, those are very musical"... we go back over 30 years, played in different bands, we both played bass in No Cal, ... I respect his kind words that rang true.

I went with two because I felt it was the thing to do for my system, and I was right. It can get very loud in here, and I seldom, if ever, run outa subs (at max levels, I can't hear myself scream, and I can sing a +4 out of an SM58). Fortunately, my closest neighbor has double pane glass and my next closest one has a garage between us. ;)

My compliments to Brian, and to Brad. I can't see how anyone could go wrong in putting together one or two of these.

[paulspencer]

I have a pair of these kits as well, although I don't run them as low as 14 Hz. You probably can't hear below 20 Hz, but it's not easy to determine. What you hear is probably harmonics. I'm not sure how you would determine that you could actually hear below 20 - how do you create a sound without content at higher frequencies? If you look at a 20 Hz sine wave input, it has higher frequency content even before it goes to the sub.

[mixadude]

It's not really hearing so much as it is feeling. I've been a professional sound engineer and mixer for decades, and have been tuning systems since the 70's when we had the Altec Hewlett Packard 1/3 octave analyzers. I know how to recognize fundamentals, and have an FFT analyzer that I used to set up my system... as well as my ears of course.

A well recorded sound effect sounds and feels much better with the extended bottom end.


If you look at a 20 Hz sine wave input, it has higher frequency content even before it goes to the sub.

Not a pure sine wave, no, it absolutely does not. If it does have any any higher frequency content, it's called distortion, and it's not a pure sine wave. All manner of software will generate sinusoidal tones on the computer nowadays. Many receivers have USB inputs that are essentially a soundcard in them. Pretty easy to get a clean sine wave into a system. I have other USB soundcards too, that I use, often to go S/Pdiff right into a digital console. ;)