Wishing a warm welcome to Rythmik Audio

[DougMac]

Well count me In!

I placed an order for a Pair of RYTHMIK D-15 SE 15.

Be sure to give us a review once you've got them set up and dialed in!

Doug

[curtis]

I'm also running an HSU MBM-12 in my setup and will also use it with the 2 rythmiks.

Try them with and without the MBM. I would also contact Hsu about changing that MBM to a sealed unit.

[Blake1214]

Well count me In!

I placed an order for a Pair of RYTHMIK D-15 SE 15.

These will replace my SVS PC12 Ultra in my HT.

Had the upgrade bug and wanted to try out a sealed sub that hits hard and low.

Was a tough decision as I was also considering the HSU ULS-15, and the SVS PB13ultra.

I ruled out the ULS-15 because of the price (really wanted a pair and was just too much)

I ruled out the PB13Ultra, mainly because of it's size and weight, it would have be tough for me to place it in an optimal position in my room.

My HT family room is about 432 sq feet or 3500 cubic feet, but is basically a rectangular room with 2 doors that close. I cut the room in half long ways for the HT part, So Its much smaller than the footage would indicate.
I'm also running an HSU MBM-12 in my setup and will also use it with the 2 rythmiks.

Hopefully they won't disappoint!

Now if Dave can just ship them fast enough for me to get them by the weekend!

Looks like we had the same subs in mind. I almost pre-rdered the PB13 but I really wanted to concentrate on SQ. Although I'm sure the PB13 would outperform my PC plus in both output as well as SQ, I decided to look elsewhere that was really about SQ. I knew I can retain ouput by just adding another sub.

When the ULS-15s came out, I was almost sure I would be ending up with a pair. At the same time, I really wanted to wait for what Dave was going to offer. I'm guessing the ULS-15 and the D-15 are more comparable. Price wise, I think they're also in the same league (after dual discount and pretty much the same if you go quads). It would definitely make the decision easier if the Rythmiks were at their original price or have discounts on multiples. Unless there's something different in the components used from when they were selling directly from Rythmiks' website, doesn't it kind of contradict with the whole Internet Direct model? This is in no way an attempt to cause any type of controversy. But just something that l thought about when considering for these subs. I may be totally wrong though if there were indeed changes or improvements on these subs.

Please let us now how they work out for you!!

[Blake1214]

Try them with and without the MBM. I would also contact Hsu about changing that MBM to a sealed unit.

I had no idea a sealed unit was an option for the MBM. Is this custom or a new unit they're offering?

[BradJudy]

I'm glad to see a new subwoofer partnership in place. The Rythmik products have an excellent reputation.

Having bamboo Sierra's, I would like to see a bamboo option, and I've posted my thoughts in the other thread.

[jedi.night]

Curtis, Dave, anyone,

I should be receiving the pair of 15 inch SE's on Monday.

Questions for all, since after research there is some conflicting ideas on calibration of 2 co located subs.

In my setup, I will most likely have them both co located center stage under my plasma TV.
Since they are identical subs, most likely they will be able to be set at identical gains to achieve calibration with my mains at 75 dbs.
However using a RS meter do I calibrate them individually at 75 dbs with one on and 1 off, and then leave them both on boosted by co location? or do I then back down the sub trim to 75 db's once they are both on together?

I will also be using audyessy with my Denon 2809, but at least I can compare and contrast easily once I get them set up, but turning it on or off.

[millerwill]

Curtis, Dave, anyone,

I should be receiving the pair of 15 inch SE's on Monday.

BTW, what is the size of your room? (Thanks!)

[RythmikAudio]

If you don't have a computer program to do this for you, I will use the following manual process. If you are using Sierra-1 or 340SE, please also let me know and I can come up with a initial setup to start with.

You will need: 1) a calibration CD. The one I use is Stereophile test CD 2, 2) SPL meter and a tripot, and 3) paper printout from spreadsheet.

Go through the measurement in the following steps (this applies to all brands):

1) Do the close mic measurement (placing the mic very close to cone in 2") on subwoofer (open up the xover point).

1a) For sealed front, do the same thing. Vented front speakers are a bit more complex as it needs to sum the output from woofer and vent. Since vent opening and woofer size is a bit different, we cannot directly add them together. However, the reading from the vent can help us determine what tuning frequency is for the front. The interesting point for vent speakers is the phase shift is 180 degrees at tuning point. For sealed box, the corner frequency point (-1db or -3db) has a phase shift of 90 degrees. This will help determine the phase adjustment we need to do. As it will be up to 90degrees difference between these two cases.

2) Do the far field measurement of subwoofer by placing SPL on tripod at your lisenting height and location.

3) Do the same for the front speaker.

4) Now do the same for both front speaker and subwoofer on.

The comparison of 1) and 2) gives you idea about the room mode you may have. The sub should have pretty flat response in close-mic measurement 1) from 10hz (-4db) to 80hz. So any big up and down in 2) is due to room modes. Try subwoofer at different location and write down their numbers for step 2) and 4) so that you can do a selection. The comparison of 2), 3) and 4) will give us idea if the xover point is good.

For vented front speakers, one needs to add phase lead the subwoofer (EDIT: I made a mistake in the original post) to compensate for the extra phase shift of vented fronts using HT receiver's speaker distance menu. Put the subwoofer farther away than what it actually is relative to front speakers can fool the receiver to pull the timing of subwoofer ahead, which is equivalent to a phase lead. In other words, to compensate for the additional phase shift for front speakers (vented in particular), we need to add phase lead (or pull timing ahead) on subwoofer to get perfect phase alignment between fronts and sub(s) when the xover point and the tuning frequency of vent front is too close. The difference between the xover set in the receiver and vent's tuning frequency determines how much of that 90 degress shift is actually affecting your setup. (Keep in mind, all HT receiver uses LR alignment design and put a 2nd order filtering on front speaker and 4th order filtering on sub, the assumption for them to do that is that at xover point the front speaker will have 90 degrees phase shift. As one can see, this assumption applies to sealed more than vented. But that doesn't mean it will not work for vented fronts. We just need to know how to adapt).

If you don't use a HT receiver, you need to be able to xover the vent front speaker higher enough than the tuning frequency (sealed box is ok). Otherwise, the best bet is to run front speaker full range. This is particularly true for those with 5" woofer in vent configuration. For sierra-1 and 340SE, if you do full range, the xover setup you want to use on plate amp is set the low pass switch to 50hz/24 and delay control at 10 o'clock position and gradually adjust the xover knob from 80hz to 50hz to see the integration result in step 4).

Please feel free to ask questions. I will put all the essential information on a integration guide.

[jedi.night]

BTW, what is the size of your room? (Thanks!)

It's about 3500 cubic feet, rectangular room. But it's deceiving because I cut the room in half long ways for the HT setup.

36 ft length X 12 feet Wide X 8 feet height. is the Total room space.

However I use about a 12 X 12 section of the room turned on its side for the HT. 2 doors but I keep them closed.

[jedi.night]

Anyone,
can you explain to me how the damping factor and rumble filter work exactly.
I believe the rumble filter is just another term for high pass filter, correct? But I'm not sure how those settings relate to damping.

My D-15 SE's will be used primarily for HT and Gaming. What settings would theoretically benefit me the most?