Help to design a bookshelf to beat Onix Reference 1 Monitor


I want help to design a bookshelf to beat Onix Reference 1 Monitor. It's for my friend who just sold Klipsch Reference RB25 bookshelves to get something significantely better. He was annoyed by the sibilance in female voices and harshness that might be caused by the horn loaded tweeter(?). His biggest complain is the midrange, he thinks the RB25 were greatly lacking in that area.

The budget is 600-700$ USD. Since he can get B stock (he doesn't care about the look) Onix Reference 1 Monitor for 600$, he doesn't want to go higher than that. He's looking for the best sound quality possible. He already got an amplifier with 30WPC into 6 ohms, so the budget is only for the speaker drivers, polyfill, crossover parts, ports, binding post and wood.

He never listen to loud music. He listen at most at 95 dB average, 100 dB average maximum. Louder than that and it's pain so he will turn the volume down. He never get past 100 dB. He sit about 5-6 feet from the speakers and don't move much.

So, he was thinking about going two-way, but since he doesn't like loud music, I suggested that he should also consider fullrange with the CSS FR125S. He want quite large bookshelves, the Klipsch RB25 stands can take about 7 inches by 7 inches speakers, so he want something to fill that. He is using a subwoofer, the HSU STF-2.

What's the best choice for sound quality? Two-way or fullrange?Considering the budget, using FR125S would leave alot of spare cash, but would it be up to par with Onix Reference 1 Monitor? Looking at the frequency response curve, there's two dips (1.25 kHz and 10 kHz) and one peak (6.5 kHz), you probably also have a narrow sweet spot to get that flat response to 20 kHz. Then if you go two-way, I'm quite sure we can get a flatter frequency response curve, wider sweet spot and lower distortion but then you get phase/time problems and a crossover. He also doesn't need that wide sweet spot since he doesn't move much.

That's what I was thinking :

Fullrange :
CSS FR125S with the current deal of 150$/pair with grilles and baffles.

Two-way :
Seas 27TBFCG tweeter
CSS WR125S or CSS FR125S or "something else" midrange

So, I want your opinion, advice and help to tell me if the FR125S is up to the task or it would be better to go two-way. If it's better to go two-way, I want your opinion, advice and help to tell me what would be a good "something else" or the CSS FR125S or the CSS WR125S would be up to the task. Remember the target is the Onix Reference 1 Monitor.

Thank you very much in advance!
Tell me if I forgot to tell something you need to know!
The Seas Trym kit may interest you as it uses the best drivers Seas makes. The parts are ~ $600. I like the idea of a low tweeter crossover that then allows one speaker to carry all the human vocal range. If you use a stand you may want to consider putting the port on the bottom of the cabinet. Substituting the lower cost Seas 27 TDFC fabric dome tweeter is worth exploring.

The Trym is a 2 way, 2 driver loudspeaker kit utilizing the latest driver technology from the SEAS Excel product line. This kit uses a single W22EX001 22cm woofer and a T 25 CF OO2 "MILLENNIUM" tweeter. . It was designed to be relatively easy and economical to build, while still providing the very highest level of acoustical performance. The Trym was designed by Murray Zeligman.
I think something like one of the Raw MTMs with the WR125 and AC tweeter would do, as would the exodus audio kits with the extremis, the criterion, Jon Marsh's modula designs over at htguide, Curt C's cryolite, and so forth. Lots of choices which should offer equal or better performance, but it unlikely you will find many people who've heard both the onix AND more than one of the above listed speakers.
soongsc said:
Why don't you just get the same drivers as the Onix and build from that if it's what your friend really likes, that way your only risk would be the XO design and the component quality.

He would like to have something better if possible. I don't even know if he already listened to these speakers. Onix drivers, at least the Vifa tweeter, seem to be really "normal" parts not that expensive. So I guess we could choose better parts.

LineSource said:
I like the idea of a low tweeter crossover that then allows one speaker to carry all the human vocal range. Substituting the lower cost Seas 27 TDFC fabric dome tweeter is worth exploring. This kit uses a single W22EX001 22cm woofer and a T 25 CF OO2 "MILLENNIUM" tweeter.

Thank you very much for this kit suggestion, I'll look into it. I wanted to use the 27 TBFCG tweeter because it's the best affordable tweeter according to Zaph, even slightly better in performance than the Millenium (can't post the model number right now, can't access to Zaph website). I was thinking in using a 5 kHz crossover so the critical range I heard about where there should be no crossover (250-5000) would be covered by the FR125S.

LineSource said:
I think something like one of the Raw MTMs with the WR125 and AC tweeter would do, as would the exodus audio kits with the extremis, the criterion, Jon Marsh's modula designs over at htguide, Curt C's cryolite, and so forth.

I will check into them too, I was thinking in using the Extremis too, but I think I could get better midrange with another driver. In a three-way with the FR125S and 27 TBFCG it would be awesome! Thank you!

Keep the suggestions and ideas coming guys! Thanks again!
Hi Simon5

The Trym has a 1.6Khz crossover point which allows integration with the W22EX001 22cm woofer. The W22 is one of the few speakers that has the surface area, and the Xmax, and the low Le motor to sound good from 30-2Khz.

A 5Khz tweeter crossover is more suited to a 3-way TMW since the cone diameter required to reach 5Khz without beaming will not have enough area to pump enough air to bring 30-40hz to life in a room. If you are building a 3-way with a 5Khz Xover, consider the the Seas 27 TDC (no fero fluid) tweeter. ..much greater air and detail.

If you want to save money.. build a well reviewed kit and don't make any mistakes.

If you want to have fun and education... design your own, but beware that the driver cost is only a small portion of the total cost
The Jordan does have a great rep, but AFAIK it is without canadian distributors at the moment, and if it is better than the FR125 (which from what I've heard is highly debateable), it is certainly not 2x better, which is what it costs. I have heard GrahamT's 'ExtremeMT' (details of which are at htguide) and I think it is the best fullrange bookshelf I've ever heard, though I could see it overpowering a small room. It would likely be in your price range, and I think it would definately outperform that Onix, and having heard the Dayton RS drivers, and having total faith in Jon Marsh's XO design skills, I'd say the same for the Modula series with total confidence, the use RS woofers and the Seas tweeter you like.


2005-03-26 2:31 pm
simon5 said:
I agree with you. Do you think it could achieve the performance of the Onix monitor?

I have not heard the Onix monitor, but I think the designer of a speaker plays an important role. It takes some time to get the best performance out of any drivers no matter how good they are. The way Jordans are designed will give very good resolution, and are not so forgiving if the source equipment are not good. Paper cones normally have slightly less resolution, but can sound very good as well if you don't notice the difference in resolution.

I certainly would like for someone would let you try before you buy, anyone doing that for the FR125? I haven't heard them before, and I don't think it's that easy to find here.
simon5 said:
I had no comments about using the fullrange FR125S alone.

I'm a big fan of the FR125 -- i'm listening to a pair right now, They aren't the be all & end all, but they are really good value for the dollar.

A single pair is also quite a bit under your budget limit.

You can consider 2 pair for a bipole (or 1.5 way system), or the addition of a helper woofer (althou with a sub already in place, the 70-80 Hz you can get out of the FR with an aperiodic box that may just be complicating things).

If you want to consider a tweeter, the WR125 is probably a better bet. You can do a traditional XO, or you can take advantage of the extended range and just add a cap XOed tweeter -- on the weekend we heard them mated with both a waveguide loaded ApexJr tweeter (diyAudio price 2 for $1 USD -- the caps & shipping are going to cost more than the tweeter) and the RAW ribbon (closest available ribbon -- the Aurum Cantus G2si). The ribbon is way too efficient for just a cap, but showed real promise once we got it tolerable by XOing with a 1 uF cap (ie 20 kHz XO). The speaker with the ApexJr tweeter was much better balanced (just a 1.7 uF cap). Despite being almost free its performance & match with the WR is very good (i've been including a pair with every pair of WR125s i've been selling) Using something like the SEAS tweeter should land you somewhere in-between. With the SEAS you also have the flexibility to build a more complex XO that brings the tweeter lower and rolls off the woofer -- a simple series XO might work well.

Other drivers to consider for mid duty are things like the Fostex FE108ES -- it has better midrange (it has better mids than most drivers) than the FR125 but won't reach down as low to meet the sub (plus getting these to integrate with a woofer is harder) & is a bit spendier. The FE127 would also be a candidate, with a bit better bass extension than the FE108ES (in a convential cabinet) but still not as deep as the FR or WR.

It is hard to go wrong with the FR or WR as the core of a relatively inexpensive speaker.



2005-08-15 8:29 pm
I just went throught the same process as you are. There are a lot of choices and it was difficult to pick one.

After waffling for some time, I went with the design using the Seas L18 midwoofer along with the TBFCG tweeter. I have just received all the parts and they are sitting in my living room waiting for me to return from a businees trip to put it together. The parts were about $650 including parts-express cabinets and better quality crossoever components I bought from Danny Richie at GR-research. The cost increase for the crossover parts was not that dramatic over the lower quality components.

I also considered the U-Pee (usher tweeter) variation of the Pee Creek design at as well as the AV-1 from GR-research. I auditioned the AV-1 and felt the mid range was not quite as forward as I like.

The Seas millenium combination sounds great (A friend of mine owns the BESL 5MT) but you would be hard pressed to get all of the parts for any Seas millenium design for under $900, especially if you used the quality crossover components these drivers deserve. At any rate, the forums seem very fond of the L18 and TBFCG drivers -- some even rate the TBFCG above the millenium tweeter.

I will document my constrction of the zaph L18 and offer my impressions when they are done.

Good luck on your project search.



2005-06-14 5:50 pm
Keep in mind that some people consider the Onix Ref1s bright. I got a set for my wife as a casual system in the den when the Ref1 + SP3 combo first came out. On the tubes they were ok, but I couldn't handle them in the HT room with SS gear. Part of the price of the Refs is the finish, if he is looking at potentially blemished B-Stock then it could be too much $ for what he is getting.

I think someone above has already mentioned the discontinued Criterions from GR-Research, but I wanted to add just the normal A/V series to the mix too. The 3s are towers, but as bookshelves you could do 1s or 2s, or even a pair of sealed 3s (only good to high 80s though). Even with Sonicaps and Black Hole 5 you won't hit $600.

I just started replacing my HT system with some GR Research AV series kits. On a lark I lugged the A/V-3s into the den and hooked them up to the tubes and we were both blown away. The 3s were much richer and smoother. They didn't seem to have a loss of detail either. She has already told me to sell the Refs and make another pair of 3s for her, but I'm sort of thinking I'll either do the new 4s or wait for the new joint venture GR-Research/RAW ribbon AV series kits.

Well, I was considering the FR125S even in the two-way since the frequency response is flatter according to the charts available on CSS website.

I know it's under the budget limit but if it's enough then why not!

Do you think I can get better sound with the FR125S with a Seas 27 TBFC/G or 27 TDFC tweeter crossed at 5 kHz with a 2nd order Linkwitz-Riley? That's what I'm thinking about. That would cost only 210$+shipping. Any problems with that idea?

I haven't heard the FR125S but I have experience with the WR125S. In the case of the WR125S the off-axis response above around 4-5K is less than optimal. The FR version may be somewhat better, but I would expect it to have similar dispersion issues in the higher frequency range. I designed a really nice minimonitor using the WR125S and the DX19 Vifa tweeter. For the money the design sounds surprisingly good. You can see my design in the last pages of this thread:

I give a couple of cross-over design options in the thread. I would recommend using the 1.8mH inductor for a more mid-forward sound and probably a 1.1 ohm resistor on the tweeter to match.

If your buddy is using a subwoofer then you might consider keeping these in a sealed enclosure rather than ported. This should "clean up" the low frequency a little since there wouldn't be any group delay. The design should play down to around 100hz nearly flat in the Parts Express box.

Personally, I would recommend using a tweeter with either the FR or WR unit since the diameter of the woofer will certainly cause a decrease in high frequency dispersion no matter what you do.

One last comment, the mid-range performance of the CSS drivers is really great and I would say that they perform very favorably tompared to other 2-way monitors I've heard.