Rythmik Servo Sub on order!

audioferret · « **on:** 14 Jan 2007, 06:06 am »

I have just ordered Kit #1 from Rythmik Audio.

http://www.rythmikaudio.com/servo_product.htm

I will be using BBB grade baltic birch for the cabinet, in a double-box configuration. I will then add a set of vibebuster8 spikes from RawAcoustics, along with the Ice Acoustic foam. I will keep folks posed as I build this.

warnerwh · « **Reply #1 on:** 14 Jan 2007, 07:51 am »

Post pics too please. I'm just learning how to build subs and the more I see the more I can learn. If you're experienced maybe some explanations on why or how you did things will help. I'm not used to finish work or making boxes for subs. I can build them square but as far as internal construction options I'm still learning.

I already built a sealed sub using a Dayton HF 15" and the sound quality is outstanding! Wished I knew about Baltic Birch before I built it because the thing weighs 165lbs. From what I've read about Rythmik subs they're excellent subs for the money. I've been using one of his amps for some time and it works well. His customer service is excellent, always responding to questions within a couple of hours.

Right now I'm building a HT sub for a friend using to SS RL-P 15" drivers. Box is of Baltic Birch and is 3'x4'x21" when done. Weight will be heavy

Hope we can get it into his truck.

Be sure to post how it sounds.

audioferret · « **Reply #2 on:** 14 Jan 2007, 07:33 pm »

Pics...of course!

I usually document my building projects on my website at:

http://www.geocities.com/ghaunadaur99/audio/diy.html

It is a piece of crap website, but it is the best I can do with minimal skills and effort. I will add the subwoofer project after I add the Mapletree Audio Magic 5 preamp that I built...and the Hypex UCD-180 monoblock amps that are in progress....

andyr · « **Reply #3 on:** 15 Jan 2007, 10:30 am »

Quote from: audioferret on 14 Jan 2007, 06:06 am

I have just ordered Kit #1 from Rythmik Audio.

http://www.rythmikaudio.com/servo_product.htm

I will be using BBB grade baltic birch for the cabinet, in a double-box configuration. I will then add a set of vibebuster8 spikes from RawAcoustics, along with the Ice Acoustic foam. I will keep folks posed as I build this.

Hi ferret,

I've just built a 2 cuft Rythmik Servo sub too and am very pleased with the unf'ingBelievable extra bass I get in my music system as a result!!

However, I'm interested to understand why you're using baltic ply? And secondly, why the same wood for both inner and outer box? Is baltic ply "extra inert"??

I certainly think it's a good idea to build a 2-box sub (to get a "CLD" box which should be very inert) but why use the same wood for both inner & outer box? IME, CLD works best with dissimilar materials ... so I used an inner box made of sheet flooring (offcuts from my renovations!

) and an outer box made of MDF.

Regards,

Andy

audioferret · « **Reply #4 on:** 15 Jan 2007, 09:50 pm »

I tend to focus on geometry to produce the rigidity I need. Baltic Birch (or any ply, for that matter) is made of alternating sheets of thin veneer that have the grain oriented at 90 degree angles to each other. The BBB grade Baltic birch has no voids in it and is a very high quality cut of wood. The alternating grains work to help strengthen the wood without adding the extra weight that MDF adds. It works like the alternating fibers in Kevlar, adding strength without weight.

4x 8 sheet of MDF weighs about 100 lbs. Plywood will weigh between 60 and 70 lbs. For bending strength, plywood is stronger, pound for pound, than steel. As for rigidity, MDF has a rating of 11.3, plywood a 10.4. The difference to me is not worth the extra weight, added difficulty of working MDF, and the carcinogenic hazards of the former. Plywood will glue stronger, hold screws better, and cuts easier than MDF.

In bracing, I plan carefully how I lay out the pieces, focusing on positions that result in different iterations of the golden ratio (1:1.618:0.618) I am pretty happy with this method. To me, the success I got with my HT3s is enough to convince me that I am sticking with Plywood on my projects. I just like it better.

warnerwh · « **Reply #5 on:** 17 Jan 2007, 02:37 am »

I'm with you on the Birch ply. It's lighter and one thickness of the 13 ply is supposed to equal 2 thicknesses of MDF. My next two boxes I'm going to use the Birch ply. I'm also just going to stain and varnish the birch. In the end it's actually less money because you need less of it and potentially you can use the Birch finish which eliminates the need for veneer. It's only 40 bucks a sheet here. That's only 15 more than mdf and the boxes I'll be building would have needed 2 sheets of mdf but only one of the birch. I'll still beef it up as well as glue some mdf inside anyway being as I have plenty.

audioferret · « **Reply #6 on:** 17 Jan 2007, 03:34 am »

I just finished the cutting of my Baltic Birch into panels. The cuts were easy and I am just waiting on the kit to come in to start on the assembly...

-AF

warnerwh · « **Reply #7 on:** 17 Jan 2007, 11:39 pm »

I just put the baffle on my box and am just letting glue dry. Did the whole thing today. That's fast for this guy.

I can build walls but doing furniture grade cabinet work isn't something I'm used to doing. I'm going to rebuild my first sub so it's a bit smaller and much nicer looking.

Tomorrow I'll put on stain and several coats of varnish. I may even try to round corner the front baffle.

I'm not used to using a router. I probably have a half an hour of experience total now.

I went with the PE 500 watt plate amp. I have a Rythmik but thought the extra power as well as having another band of parametric equalization would be worth a few bucks more. Besides they're on sale. The driver I'm using is the Dayton RS HiFi 15" in sealed cabinets.

If you know of a wood filler that doesn't shrink I'd appreciate it. I have two kinds, both say they don't shrink, both do. Thanks

satfrat · « **Reply #8 on:** 18 Jan 2007, 07:48 am »

Quote from: warnerwh on 17 Jan 2007, 11:39 pm

I just put the baffle on my box and am just letting glue dry. Did the whole thing today. That's fast for this guy. I can build walls but doing furniture grade cabinet work isn't something I'm used to doing. I'm going to rebuild my first sub so it's a bit smaller and much nicer looking.

Tomorrow I'll put on stain and several coats of varnish. I may even try to round corner the front baffle. I'm not used to using a router. I probably have a half an hour of experience total now.

I went with the PE 500 watt plate amp. I have a Rythmik but thought the extra power as well as having another band of parametric equalization would be worth a few bucks more. Besides they're on sale. The driver I'm using is the Dayton RS HiFi 15" in sealed cabinets.

If you know of a wood filler that doesn't shrink I'd appreciate it. I have two kinds, both say they don't shrink, both do. Thanks

Maybe you'd consider starting another thread on the PE 500 when you've had some time with it? I'm considering a new plate amp and would like to hear something about both these amps. I haven't had too good of luck with plate amps,,,,,

Robin

audioferret · « **Reply #9 on:** 18 Jan 2007, 04:29 pm »

Warnerwh,

What was wrong with your experiences? Was the quality of the amplification unsatisfactory, or did the amps simply not meet power expectations?

warnerwh · « **Reply #10 on:** 19 Jan 2007, 02:29 am »

The Rythmik amp is fine. The PE amp puts out a bit more power and has a band of parametric equalization. I just installed the sub a half an hour ago and am letting it break in. I think the Rythmik amps are good values but in this case I just opted for the PE amp especially since they were 60 dollars off.

Before the Rythmik I'd been apprehensive about plate amps but that one was never driven too hard. The PE amp will be driven hard as I'm crossing out the bass from my mains at 55hz. Before I had just been augmenting my speakers with the sub and running my mains full range as I now have two diy subs. I seriously considered buying a Behringer amp but the fans and space were a consideration. Hopefully this PE amp will work as it
should.

This is the sub I pretty much finished today. I still need more stain and will varnish it but wanted to try it out.

audioferret · « **Reply #11 on:** 19 Jan 2007, 03:04 am »

So, you didn't go for the servo option? From my understanding of what you wrote, you are using the PE500 and the Dayton RS HiFi 15 in you rcurrent project. Am I correct? Did you play with the Rythmik amp much?

I will be very interested to hear your thoughts on any comparison you can give. The main attraction for me with rythmik is that the amps and drivers are specifically tailored for each other to produce a combined effect.

Do you see much of a difference in build quality between the two amps?

Good Luck!
-AF

warnerwh · « **Reply #12 on:** 19 Jan 2007, 04:13 am »

Judging the Rythmik which I haven't seen in two years and the one I just got is impossible. The Rythmik was open on the back and I remember thinking it was well made. The PE amp is closed in the back. Most of the Dayton brand stuff PE carries is of good or better quality.

The Dayton HIFI 15" I'm using is an excellent driver. I understand most of these drivers in the Reference Series of PE perform as well as big name brands without the high cost. There's a bunch of guys who measure them to see exactly how they perform so this is not info from their website. Alot of the diyers use Dayton drivers because of this.

andyr · « **Reply #13 on:** 19 Jan 2007, 08:03 am »

Quote from: audioferret on 19 Jan 2007, 03:04 am

So, you didn't go for the servo option? From my understanding of what you wrote, you are using the PE500 and the Dayton RS HiFi 15 in you rcurrent project. Am I correct? Did you play with the Rythmik amp much?

I will be very interested to hear your thoughts on any comparison you can give. The main attraction for me with rythmik is that the amps and drivers are specifically tailored for each other to produce a combined effect.

Do you see much of a difference in build quality between the two amps?

Good Luck!
-AF

Hi ferret,

Yes, the Rythmik amp and driver are specifically tailored for each other to produce a combined effect ... but more importantly, it offers a servo option. I think this is important for getting good flat LF.

Regards,

Andy

audioferret · « **Reply #14 on:** 19 Jan 2007, 08:12 pm »

My Servo Kit arrives tomorrow! Whoo-Hoo! I am obviously very excited. I have finished testing the box cutouts and braces. Once I add the cutouts for the front driver and the rear amp, I can start assembly and testing pretty quickly!

Waiting...as patiently as I can. I check the front steps every hour...

warnerwh · « **Reply #15 on:** 19 Jan 2007, 11:47 pm »

I know how you feel. Yesterday I was waiting for my package from PE til 4 p.m. I kept checking the UPS site to make sure there wasn't an "exception" which is when they moved the deliver date up.

When the box got here I opened it, cut out a hole in the back of my box took it to the basement, put in the amp and driver and hooked it up. I don't know how long it took me to do this but it couldn't have been too long as I burned right through it. Almost forgot the foam gasket behind the driver

.

Hopefully your stuff will arrive on time. I wouldn't want you losing sleep.

audioferret · « **Reply #16 on:** 22 Jan 2007, 04:55 pm »

Well, the kit arrived on Saturday and I busily got to work. So busy, in fact, that I didn't really document much. I will snap a few pictures this evening. I have the majority of the box finished, only needing to flush trim and mount the front and rear baffles. Sawdust everywhere. The box is quite square and the panels fit together ALMOST perfectly. I just picked up a tube of wood putty to fill in a few teeny gaps...

I am pausing to consider how I want to finish the box. I am debating between simply veneering the whole thing and applying a combination veneer and wood trim solution...

-AF

warnerwh · « **Reply #17 on:** 24 Jan 2007, 09:36 pm »

Well it's been this evening for a few days now

Where's our pics?

audioferret · « **Reply #18 on:** 24 Jan 2007, 11:45 pm »

Quote from: warnerwh on 24 Jan 2007, 09:36 pm

Well it's been this evening for a few days now Where's our pics?

I finished the sub Sunday Evening at 12:00 Midnight - Really! I have now run 10 hours of warm-up music and I should be able to get pictures by the end of this evening. Bare box, of course, veneer is going to take a while.

The combined box and amps weigh 90 pounds! Any suggestions on how to determine how much stuffing to add?

-AF

warnerwh · « **Reply #19 on:** 25 Jan 2007, 12:27 am »

Personally I start with it about half full of non compressed fiberglass. I've read that starting at just lining the walls and adding 8oz until the sound gets muffled and remove that last 8oz.