Nope.

Sorry, not RBH either.

Like I said, lesser known brand.

Nope.

It's an American brand.

Well done!

Yes, indeed it is the F15.

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Added on July 21, 2009, 11:15 pmThat's correct. I got the PEQ version. D2A shipping was $200.

This post has been edited by jchong: Jul 21 2009, 11:15 PM

Yup, getting bigger but not too HUGE in my case. One reason why I went for sealed design is to keep the size manageable.

For the F15 size is 19" x 19" x 20", which is quite compact considering the 15" driver. By comparison the SVS PB-12NSD (which I did consider) is 18" x 21" x 25".

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Added on July 22, 2009, 9:39 amYup, Ascend started carrying the Rythmik line about Oct/Nov last year.

I'll do a review once I've set it up better.

This post has been edited by jchong: Jul 22 2009, 09:39 AM

Congrats on the Velo! Looks like both of us managed to get what we wanted to get

Warranty is 5 years for the driver, 2 years for electronics (amp). Hmm... didn't ask about the shipping for replacement parts. Will go and find out.

Preliminary look at the Rythmik F15

Thanks to some test tones and a SPL meter borrowed from a forummer (you know who you are ) I managed to chart the in-room freq response of the F15 vs the CHT-12Q.



As you can see the F15 digs down to 10Hz in-room!! And it's fairly flat from 10-32Hz. By comparison the 12Q falls off rapidly below 32Hz and is basically inaudible from 25Hz and below.

So what does 10Hz sound like? Well I can't hear it. I can only start hearing some pulsations about 14Hz upwards (and this is probably due to the vibration of things in the room rather than the test signal itself). And at the test level of 80+ dB it's not powerful enough to really rattle the room. I've not tried pushing it higher yet.

Playing back a few scenes from Kung Fu Panda, the F15 is certainly tighter than the 12Q. It doesn't rumble as much. On the 'skidoosh' scene the explosion is more palpable and I can hear the bass textures as the explosion ripples across the screen (on the 12Q the bass was less defined). Yet, strangely on some scenes like when Tai Lung falls from the sky the rumbly nature of the 12Q seems to add more punch. Need to do more tweaking, especially how to use the parametric EQ on the F15.

The meter was about 3.1m away from the sub.

No, didn't cut it at 50Hz. The roll off must be due to the room I think (some nulls or holes). Now got to find way to correct for the room acoustics to balance out the area from 45-80Hz.

I'll push the sub more later once it's broken in.

Yup, I'll need to factor in the correction next. I did download the CM-140 cal file from REW.

As for REW I was itching to use it but realised I don't have everything yet, e.g. some of the cables. Particularly, I saw the note about not using the mic-in on the notebook, so it seems I might need to buy an external usb sound card too? When you used REW did you plug straight into the notebook or used an external sound card?

Can't compare between the SVS graph and mine since mine is in-room, whereas the SVS is probably ground plane. The test conditions are totally different.

Anyway, doing an in-room test is quite illuminating since it reveals how your room interacts with the sub. The effect of room gain and peaks and nulls will also become apparent.

If there is a cutoff, what is doing the cutoff? As you said the freq chart from 50-101Hz is about the same for the F15 and 12Q so it can't be anything on the subs right?

In my Onkyo 876 the LFE is set to 100Hz. Note: the freq test was done with all EQ off so Audyssey was not in effect.

Yeah, I know it's quite weird. Scratching my head how to counter it because like you said even equalizer might not be enough since the drop is so much.

As for bass trap, that only helps to reduce peaks right? Can it help to boost up valleys?

I cut the front speakers at 40 Hz.

My test tones are mp3 files. I played through the PS3, which is connected to AVR via HDMI. If I play the test tone I think it will be output via all speakers. So to test the sub, I unplugged all the other speakers. I did also test just the front speakers only (the rest unplugged) but haven't charted it yet.

Shouldn't be. If I cut the front speakers at 40Hz, it means freq lower than 40Hz are not sent to front speakers right? Should have no effect on the sub.

Sub as you said is controlled by the LFE setting, which I set at 100Hz.

Does it work that way? i.e. setting front to 40Hz means only 0-40Hz goes to the sub? I thought the sub is governed only by the LFE setting.

anfieldude, you have the 876 also, does setting the front to 40Hz means only 0-40Hz goes to the sub?



Yes, the MP3 doesn't have a .1 channel or any multichannel info, so the AVR outputs the same signal equally to all speakers incl the sub. When I play the test tones to only the sub I can hear the signals from 45-101Hz (though at different loudness).



Yup planning to do that next. One thing, it is only a stereo line out to the AVR's CD input. In this case will the 876 output this signal to the sub? What mode do I have to set the 876 to in order for it to output to the sub? Otherwise I'm afraid stereo line out means going to the front speakers only.



Actually Audyssey even set my fronts to full band, but I changed to 40Hz. Current using PSB T55 which -3dB freq response is spec'd at 32Hz. That's why I set to 40Hz. Is there any difference if I set it higher than 40?

This post has been edited by jchong: Jul 23 2009, 04:01 PM

You guys are right.

When I changed the fronts to 80 Hz I do get more output from the sub. However, the peaks and valleys are still in the same places, so those are probably due to the room.

Note: in the chart below, the correction factors for CM-140 have been applied.



This post has been edited by jchong: Jul 24 2009, 09:35 AM

Don't know if I want to push the sub to its limits

Anyway, at Home Theater Shack the 12" Rythmik was tested (ground plane, 2m) and at 20Hz it produced 94.4 dB. See here: http://www.hometheatershack.com/forums/sub...nformation.html

The 15" Rythmik is supposed to have 3-4 dB more output than the 12". But even so, it would not reach 105 dB @ 20Hz.

This post has been edited by jchong: Jul 24 2009, 09:58 AM

I agree that more bass headroom is best. But any reason why focus only on 20Hz? In a big bass heavy scene the peak might not be at 20Hz, it might be maybe 30-50Hz.

After playing around with some more settings and doing more listening I think I know what is happening. With the CHT-12Q I found out that it doesn't generate significant bass energy below 28Hz in my room (it falls off very rapidly). See the graph I posted earlier. As a result to get the punch I want, I was turning up the gain on it.

Previously, I used the skidoosh scene on KFP as a reference for spl and the 12Q hit about 98-99dB. But much of this I suspect comes from 30-50Hz region on the 12Q since there's far less pressure from 28Hz and below.

Compare this to the F15 which is fairly flat to 16Hz in my room and still has some output down to 10Hz. Going back to the skidoosh scene, if the F15 hits 100dB on this scene the spl is coming not only from the 30-50Hz region but also from below that as well. In other words, the make up of the 100dB from the F15 is different from that of the 12Q. The 12Q is running quite a bit hotter than the F15 in order to make up for the lesser energy below 30Hz.

So really in other scenes I wasn't getting that punch from the F15 because the level knob was lower than the 12Q (and also I imagine the bass spectrum for other scenes is different). I just had to increase the sub trim in the AVR and the F15 would shine! This also meant that the skidoosh scene would now sound truly monstrous! So much so that too many things in my room rattle now. To tame the vibrations in my room for the skidoosh scene I had to set the F15 to 28/Hi damping.

Anyway, I now know that the F15 can generate much more bass energy (especially down below) compared to the CHT-12Q. Just watched Valkyrie today and it had some very good bass moments.

Also, I moved my sub around and found that middle of the room produced a smoother response than left/right side. Also ran Audyssey after that and the comparison chart is below:

Heard that SVS will be coming out with 2 new sealed subs later this year. One 13", another 16"!

You can check their website for branch locations: http://www.alaudio.com.my/

I think some of the branches would have the SPL1200 for demo. I've seen one in the Amcorp Mall branch. Give them a call to confirm.