Ok, I have been waffling for quite sometime now about adding sub(s) to my system.  Currently running Woo WTP-1 transport into Woo WDS-1 DAC then feeding CSP3 to LTA ZOTL 10 or SE84UFO2.  I love both amps and can’t seem to make a choice on which one I like better, it depends on which one I’m currently listening to, LOL!  It’s good to have options, right?  My speakers are Omega Super Alnico High Output Monitors on Skylan stands.  I was going to get dual Rythmik subs or have Louis make me 2 subs that Match the Cherry wood of the SAHO Monitors but I have read that other members swear by the ZROCK for bass support.  ZROCK much cheaper than 2 subs as well as much easier to get by the wife, lol!!  Any opinions on which way to go?  My room is quite large and would take two 15” subs to “pressurize” the room according to Rythmik.  Not a bass head just looking for some low end support.  

Thanks,

I'm with Mark on the ZROCK2.  Best addition to my system, by far!  With it, I would never consider a sub -- no need.

My HR1s are spec'd down to 32HZ and until I got the ZROCK2 I never really heard their low end properly.

I could be wrong, but I am not sure anyone here has had an opportunity to hear the ZROCK2 with more than one cap type.  With that said, I got the Type II Jupiter Copper Foil caps and love it, but I have not heard any other caps in this device.  I am afraid everyone else, except Steve will be in the same boat.  You will get varying opinions from others who have a particular cap type but none of us have a real point of reference when it comes to comparing the cap types we chose with any of the others in our system.  Probably best to give Steve a holler to really understand the differences. each may make in your system.  

Do note, if you choose the Jupiter Type II's or the VCap's, it make the ZROCK2 non-refundable.

Good choice on the ZROCK2--it's a wonderful component that will benefit the entire system.

I haven't heard different cap choices in the ZROCK2. I have had three different caps in two different CSP2+ preamps and a CSP3 though: the stock, the Type I beeswax and the Type II. I believe I have a sense of the differences in the caps. The stock are good. . . great really. They have a touch of warmth and solidity that is quite involving and are probably the most "forgiving" choice. The Type I brings a dash more detail and "openness" and the Type II another dash to the point that with the Type II yoiu don't really feel you are listening to the caps, you forget about that aspect. That does come with a bit of a downside in my system though--a medicare recording is more fully revealed as wanting. And bad recordings don't stay in the player long. . . .

I would match whatever caps you have in other Decware components you might have. . . or go for the gusto and get the Type II. (I have no experience with V-Caps).

Cool, I forgot about that thread!

JB, Good choice. ZR2 w/type II caps have made a great impact on my system too! You'll be fine.

And please give us a full report of the results when you get it! : )  

When I read your question, a great one btw, the things that flash through my head are these:

1) Are the speakers capable of more bass?

2) Subwoofers can do nothing for midrange tone and the ZROCK's midrange tone is really almost its biggest selling point.

With regard to 1), many speakers that don't seem to have much bass can actually have a lot of it with a little help. Others don't respond well to the help. For example, the NFX speaker design in our DIY section of the web site use a single 8 inch full range driver in a fully vented cabinet where the vent area is top to bottom on both sides, so bass below 50Hz is obsolete. This is at least what we thought until one night we put an amplifier on them that had a bass control and turned that control up a bit. It was amazing, suddenly the speaker easily reached 35Hz and sounded full doing it.

With regard to 2), subwoofers become more and more problematic as the fidelity of a system gets higher and higher. This is because the larger heavier cones have more moving mass to deal with the extra power so that distortion is not developed in the cone. The drawback to this is that the higher moving mass slows everything down and the speed of the subwoofer can no longer keep up with the speed of the more efficient driver you're listening to. So any time you can figure out a way to not use a subwoofer you're usually better off.

As a side note, in the 1950's a subwoofer used a high efficiency 15 inch driver in a 28 cubic foot folded horn that was the same sizde as your side-by-side refrigerator in the kitchen.  These were fast.  Today we try to shrink that performance down to a cube and make the woofer move 20 times farther to compensate for the 20 times smaller box.  it's pitiful.


I would say that at modest volumes the majority of speakers would be able to put out more usable bass and lower useable bass without getting into the associated distortions, and even a speaker that rolls off at 50Hz, just hearing 50 Hz up to 12dB or more louder than you are with the added bonus of the midrange bloom would be no different than hearing your speakers sound twice as good as they ever have.

To get the midrange magic I'm talking about you have to understand two things:

1) The bass and the midrange are not separable like we think they are.

2) The harmonics of the two must be perfectly matched for audio nirvana to take place.

So again, with regard to 1) When you hear a kick drum tuned to 40Hz and record that drum you see it has harmonics up past 20kHz.  So you delete them to see what would happen and kill everything past say 500Hz. Drum sounds like turd hitting a Rubbermaid garbage can.  

So when we take a recording of the kick drum and play it back on a system that spits the signal to go between a subwoofer and a speaker, each with different phase angles and different locations in the room, that intimate link in the harmonics is broken. Harmonics are like DNA.

We listen to the drum kit recording on a speaker that has a single voice coil doing all the music with no crossover and we can easily hear that the tone of the drum suggests it's made from maple, whereas a different kick drum is made from birch. We can tell the type of drum head is on the drum and even the type of mallets and peddles are used. We can tell how the microphone(s) were placed, if the drum had pillows in it, if there was a hole in it, etc, etc, etc. All this information comes from the harmonics, so the lesson there is don't jack with the integrity of the harmonics by splitting it up into different amplifiers and even in some cases different drivers in a multi-way speaker.

With regard to 2) Audio nirvana happens when high-fidelity playback breaks the "reality barrier" and becomes indistinguishable from live. Something only possible in systems that have perfect harmonic accuracy relative to itself... things that skew this accuracy are basically time delays occurring between the input and output of amplifiers (called phase angle) and loudspeaker drivers and crossovers. Also negative feedback in amplifiers and subwoofers especially can create severe and irreparable timing errors in the music. This is in fact why main stream high-power solid-state and tube hi-fi of today can't get there.  

You might ask why engineers who design solid-state and tube amplifiers would use negative feedback if this were happening and the reason is that the distortion figures of an amplifier are lower with it. Ironically it is called "harmonic distortion" that is reduced by negative feedback when I've just pointed out that what destroys harmonics are phase-angle differences between the recording and the playback system relative to the start time.  Obviously there is a discrepancy between what looks good on paper and oscilloscopes to an Electrical Engineer (which also is what sells amplifiers to the masses) and what actually sounds good enough to create true audio nirvana...

You are twice as likely to find audio nirvana with a ZROCK on a single pair of speakers with a good no or low feedback amplifier as you are with a subwoofer, I can guarantee it... unless you want to build a REAL subwoofer, like the 28 cubic foot folded horn I mentioned. That is your choices. And Ironically if you can build a folded horn cabinet that big for a 15 inch driver for real sub bass, you'll find the similar thing to the ZROCK in that everything you play through it above that frequency also sounds better due to the richness of scale.  So then you turn your "real" subwoofer project into a full range speaker by ditching the low pass crossover and running it full-range with in some cases help from a good tweeter.  

Come to think of it, everything Decware makes comes from specific voicing or memories of things I've heard that I like, and the ZROCK rather brilliantly mimics the sound of a Decware Imperial folded horn. That is to say it makes little speaker sound like one. God only knows what would happen if you actually paired a ZROCK with an Imperial!!!

Don't worry, I'm on it.

Steve

I agree, that's a great explanation. I need another ZROCK2 for my second system. I think I'll order one now. . . figure out how to pay for it later! This way I can get on the build list and have time to sell a few things. . . .

Touche Lon!!!  I think I might do the same!!!

Tone-Deaf,

Welcome back and thanks for your post!  The way to find out if your speakers are up to the task of making bass with a little help is pretty easy.  Just download a frequency generator app for your phone, plug in a 3.5mm stereo to male RCA cable and us it as your source.  Use the app to slowly play individual frequencies in the bass region.   Find out what the lowest frequency the speaker will play that you can still feel, set it on that frequency and then see how far you can turn up the volume before the speaker begins to distort.  I did this last week while checking a pair of our DM945 bookshelf speakers and found they easily can shake the room at 35Hz.

Steve

Steve - thank you for the reply, and the clear suggestion about how to assess if the Zrock can help "extend" the deep bass on a particular speaker.  It makes total sense to me, and I will try that in the near future.

And again, I appreciate the insight you and the members of this forum provide in these posts - very helpful!

Ok, before I place my order for the ZROCK2 does anyone have ANY insider information in regards to mid-summer discounts?  Special forum member discounts?  Hey!!  I think Steve likes me discounts?  Not sure if I can wait until Christmas time to receive the Holiday percentage off deal either.  If no one has any of this information then perhaps I can order this ZR2 and put it on Lon’s account!!   .  Lon, you OK with this?

I'm not aware of any discounts. Can't hurt to try though, give Sarah or Steve a call!

I'm afraid I don't have an account with Decware to use or not use. If I had one it's drained. . . I ordered a second ZROCK2 this week.

Hope you place an order and get on the build list!

Thank you, Johnny for the reply.

Brian

Interesting Steve, that never occurred to me.  Is that why you can hear the little Honda Civic with two 18” woofers coming from literally a mile away?  

Lol!!  Love it!!  All kidding aside it must be difficult to gear a great sounding car audio system for the driver position considering the driver sits in the front left quadrant of a very small listening room.  Can probably tune it better with the old balance and fade controls and 4 speakers rather than today’s 10 to 20 speaker systems.  But......if you’re just cranking bass heavy tunes then the two 18’s will suffice.  Sorry, this thread has gone in a different direction.  Back to the ZR2, ordering mine on Sunday with Beeswax Type II’s, silver jacks and either ebony or gold knob.  Does anyone have an ebony knob on their Decware gear?  If so, do you like it?

And to add to the sub discussion, it really also depends on how you intend to implement and power the sub(s).  Do you intend to run and active or passive crossover?  Will there be a dedicated amp for the sub? Or will you run it in parallel with your stereo speakers?

There are many things to consider when making this decision.  I think the ZROCK2 is a great device, but it will never supplant a sub or bass driver in certain situations.  Defining your spectrum of bass needs is important in determining if a low bass driver of some type is necessary.  Is this for music only?  If so, what type of music?  Low bass requirements is dependent on the music you listen to.  Will this system also service your home theater needs?  Movies will work your bass drivers in ways music will not.  

Also, I have personally run through several amplifiers to drive my dual 15” Caintuck OB Augie’s.  The amp matters.  If considering a passive bass driver needing amplification, don’t assume any old amp will do.  Will it do?  Yes.  But “do” is a matter of preference.   Berringer, Crown, Dayton, did not “do” it for me.  They are fine.  But when I have invested so much into my system, I sought better and it made a difference and the added cost is to this day without regret.  

I like my ZROCK2 and I like my bass drivers/amp.  I would not be without either.  I think the ZROCK2 is a wise first choice if your typical music is not low bass hungry, or you are not assigning your system to Home Theater duty.  Otherwise, a logical next step will be to integrate a thoughtfully specified bass driver and amp combo.  

At the end of the day, we love our gear don’t we?  Finding a rational reason to support our already made up minds is what we do best.  

Thanks guys!!  Ebony it is then, it does seem more of an elegant look and have more worldly meaning.

Jeff, thanks for digging into this.  There is a lot to think about besides buying 2 powered subs and setting them somewhere in the front of the room.  The plan was 2 powered subs running in parallel with the Omega Super Alnico High Output Monitors.  Hadn’t yet thought of how I would integrate those.  Use the Mono Output on the CSP3?  High level from amp?  Placement?  Settings?  All I read about integrating sub(s) is it can be a tough task so I’m thinking you’re right and the ZR2 is a very logical first step.  I have older Mirage OM6’s with built in subs handling H/T duties so the subs would strictly be for music on main rig.  Lol!!  Even more reasons to support my made up mind.

On the knob debate. I ordered my first ZROCK II with a black Chicken head knob but it came with a gold knob...I've been meaning to call Sarah and get a White Chicken Head sent.  The second ZROCK II I bought used had a white chicken head knob and it makes knowing where it is turned to much easier to see. I preferred it from the moment I started using it.  The newly purchased Rachael also has a white chicken head...all my other gear has the gold knobs.  Mark.

So I finished testing my speakers and they do not look like they would be helped by the Zrock.  The bass response drops off rapidly at around 50 hz, and when I turn up the amp, it starts distorting before it gets very loud.  

Maybe a sub would help me, but I think a more logical first step is to replace the speaker with ones that have frequency response that goes lower than 55 hz, and then decide on further steps.  In any case, I am glad to have a clearer picture of what my present speakers are capable of.

JohnnyB, I hope the Zrock does the trick on your speakers, and I will be watching for your reports on how it works for you.  It looks like you have some low end that the Zrock can work on.

Mark, that’s exactly where I’m going to go if the ZROCK doesn’t get me where I want to be.  There’s no doubt in my mind th3 ZR2 will make an improvement, just need to see if it’s what I’m looking for.  Why not try the easy way out first and if I need a sub or two after the fact I will have the ZR2 to play ari7nd with as well.  Louis told me he would make whatever I wanted and did have suggestions of front firing subs.  Another benefi of having Louis make something custom is he can match the subs wood grain / color to my Cherry Alnicos rather than having just a black box.

Johnny, I am running my ZROCK2 in between my ZBIT (fed by my ZRTPRE) and my CSP3-25, which then feeds my SE84UFO3-25 Monoblocks.

The only time I encounter "overloading" is when there is very heavy low frequency energy in the material (mostly DVD or Blu-ray, occasionally heavily EQ'd Redbook) and the ZROCK2 is "dialed up" heavily with its own gain up and EQ boosting the bass. It's rare to experience the overload and distortion, and it's easily fixed with dialing back the ZROCK2, or "riding the gain" in the system, which in my system can be by adjusting gain from my DAC, ZTPRE, ZBIT, ZROCK2, CSP3-25 or the amplifiers. LOL.

I too wondered if this would be an issue, and it really isn't, or very rarely is.

Johnny, I don't have the answer about the volts except to say that the CSP3 will put out GOBS of voltage, and the ZTPRE even a sixth more or so. I need the gain as my DAC output is less than 4 volts using the balanced output, and the amps really like voltage into the input. I have the ZTPRE gain turned up about halfway and usually the volume full up (even though I have a remote installed I don't often use it), my ZBIT at about 90 percent, my CSP3-25 at about 40 percent output, and my SE84UFO3-25 amps at about 85 percent gain. The ZROCK2 is at about 2 to 4 o'clock. Everytime I play around I end up in about this configuration so I don't often play around with the gain, most tinkering is with the ZROCK2 and I use the volume on the CSP3-26 mostly to control volume between sources and selections.

Hopefully Steve will chime in about the voltage specs differences.

We like what we like. And yes, I feel the ZROCK2 is the vital key ingredient in my satisfaction. As Johnny Slate noted elsewhere in the forum, my room situation sucks bass energy and the ZROCK2 allows me to compensate for that remarkably. It's my saving grace and with some adjustment I can almost always get just the right tonal balance. I'm sold on the ZROCK2 and one day will get another for my second system.