[THWO]

Hi all,

I have started planning an "ultimate" open baffle - project (I know, there will never be a final version and there´s never an end, but that´s another story...). However, it still has to meet some minor size restrictions (i.e. WAF) and it has to integrate into our living room.

So I started with some basic considerations.

Size: If possible, the baffle width shall not exceed 17-18 inch (ca. 45 cm) and height shall not be more than 49-50 inch (ca. 125 cm). Winglets or a small U-frame to extend the width of the baffle is ok, if necessary, but I would prefer without. If there shall be any, it should be restricted to the woofer section.

Technic: I think of setting two 15" woofers, one midrange and a tweeter per side. Driven either completely active or, what I prefer at present, crossing mid and tweeter passively and driving woofers and mid-high with two stereo amps plus DSP.

Overall design considerations: Being quite impressed by some very interesting projects here in the forum, I am open for considering decoupling woofers from mids and reducing the baffle around mids and treble may be even to zero, let´s see. I will start with test baffles and cut them down inchwise while taking measures all the time. May become a fascinating task. Or I´ll stay with a nicely structured baffle - as I said, still undecided.

I am pretty much focused on an AMT tweeter and think of a Mundorf or the Beyma TPL 150H. At present, I prefer the latter. Back cap removed, of course. Choosing the woofers took me quite some time. Today, I think the Precision Device PD 154 may be a good choice. I need the system for listening to music, not home cinema. I don´t like woofers booming around subsonically all the time, but prefer fast and acurate, "dry" reproduction. So it does not have to blow full 20 Hz, some 35-40 Hz well done should do, I think.

Thanks for your patience so far. Now I am looking for a matching speaker for the range between 150 or 200 Hz up to 2,000 Hz. What comes into my mind are Beyma 10 MW/ND or  10G40. However, it is almost not possible for me to see the relevant differences between those two to make a decision. Regretably, I did not find measures taken under ancle. While the frequence script under 0° looks fine to me, I doubt that there might be quite some beaming, given that diameter? Would 2,000 Hz still be ok? Optically, it would nicely fit between the size of the woofers and i.e. the Beyma TPL 150H which is not really small, indeed.

Or would you, as a principle, prefer me to go for a 8" mid instead a 10" (i.e. in regard to beaming or "speed")? If so, how about the Ciare PW 205 ND? Looks fine to me, too.

Another option may be to think of the BG Neo 10 together with the Neo3. But how about bursting dynamics and playing loud? I have no experience with those speakers. The seem to enjoy an excellent reputation, but someone recommended a cone mid for better dynamics. Is this a valid aspect?

I am not finally decided on any of the speakers mentioned. In case you experienced guys can give me a go on the woofers and tweeters (either one), my question is what to look for in regard to clean and dynamic mids. Any suggestion is more than welcome, and any general ideas as well.

In case you are interested in my two OB-projects I did until today, or in its pictures (as it is all German), you may have a look here:

http://www.hifi-forum.de/viewthread-104-22355.html#7  and
http://www.hifi-forum.de/viewthread-104-21512.html

Thanks in advance,
Till

[THWO]

I am pretty much focused on an AMT tweeter and think of a Mundorf or the Beyma TPL 150H. At present, I prefer the latter. Back cap removed, of course. Choosing the woofers took me quite some time. Today, I think the Precision Device PD 154 may be a good choice. I need the system for listening to music, not home cinema. I don´t like woofers booming around subsonically all the time, but prefer fast and acurate, "dry" reproduction. So it does not have to blow full 20 Hz, some 35-40 Hz well done should do, I think.

Thanks for your patience so far. Now I am looking for a matching speaker for the range between 150 or 200 Hz up to 2,000 Hz. What comes into my mind are Beyma 10 MW/ND or  10G40. However, it is almost not possible for me to see the relevant differences between those two to make a decision. Regretably, I did not find measures taken under angle. While the frequence script under 0° looks fine to me, I doubt that there might be quite some beaming, given that diameter? Would 2,000 Hz still be ok? Optically, it would nicely fit between the size of the woofers and i.e. the Beyma TPL 150H which is not really small, indeed.

Or would you, as a principle, prefer me to go for a 8" mid instead a 10" (i.e. in regard to beaming or "speed")? If so, how about the Ciare PW 205 ND? Looks fine to me, too.

Another option may be to think of the BG Neo 10 together with the Neo3. But how about bursting dynamics and playing loud? I have no experience with those speakers. The seem to enjoy an excellent reputation, but someone recommended a cone mid for better dynamics. Is this a valid aspect?

I am not finally decided on any of the speakers mentioned. In case you experienced guys can give me a go on the woofers and tweeters (either one), my question is what to look for in regard to clean and dynamic mids. Any suggestion is more than welcome, and any general ideas as well.


Thanks in advance,
Till

[studiotech]

You will not be able to push a single Neo10 down to 100 or 200 Hz.  I am loving my system with 2 Neo10, but I don't know what your idea of "loud" is.  Are you talking 100dBspl or like 120dBspl?  I also enjoyed the Eighteen Sound ND 6" that Zaph tested.  That would have been a possible choice if I went with a cone driver.

Greg

[THWO]

You are right, Greg, loud is relative...
I do not listen extremely loud. But I like dynamics. I listen to classics and jazz most of the time.

Thanks for your hint to the ND6". Would prefer a 6" over a 8" in general or just in this case?

By the way, I admire your solution with the two Neo 10. Very well designed and finished...


Till

[jkelly]

I don't think this is the perfect midrange, but this system has been extremely enjoyable for me over the last 3 years:

http://www.audiocircle.com/index.php?topic=65570.0

Jeff

[SteveRB]

Sounds like you are making a real high level system.

I have recently gone from two 15" woofers back down to one. I found the two woofers over baring in my room and slightly smeared the mid-range.

Now the midrange soars and the bi-amped bass still punches me in the chest. Everything goes louder than i can stand. My baffle is 18" wide and 46" tall: no wings, in my experience, they tend to suck the life out of the narrow baffle designs.

[Ric Schultz]

I think you will get more transparency with the Neo 10s....yes, run two of them.  But you might get better dynamics from a large midrange cone (or a Bastanis Chrystal 12) or two smaller ones that get close to 100db.  I want to hear the instruments as pure as possible and two Neos should rock you till the cows come home.  I realize that 2 15s and two Neos and the Beyma would be taller than what you want.  Why limit the height?  Go for it!  Tell your wife a tall speaker will make you feel more manly and a better lover....he he.   Or like Greg use one 15 on the panel and use a sub (I think a very, very good idea!...my vote!).  You could also get the GR Research 12 inch servos and two of those would not be that tall and would give you tight ass bass to 20hz or lower (well, if you use 2 Neo 10s will still be too tall).  If you look in my picture Gallery you will see a prototype baffle empty and laying down with two Neo 10s, a Neo 3 and 2 12 inch servo woofs in it....stands 56 inches high on its base with footers but because it is narrower on the top is very nice looking, the pics are taken at weird angles so you don't get how nice they appear).  Another option would be to put one 15 inch woofer in an H frame (magnet braced, of course) and then have another base on top with its baffle loaded with the mids and highs.  This way the bass is more extended due to the H-frame and needs less eq for lower bass and you can put some isolation material between the H frame and the base of the uppers so you get some isolation from the bass frequencies....would sound better, for sure, but not look as pretty.  No matter how good you make the baffle, time align, felt, brace, magnet brace, hardwire all drivers (no binding posts) and do all the good stuff it still will only be as good as your xover and amps, cables, source, room, etc.  if you are going all out, then you must think tweak at all levels.

[Rudolf]

However, it is almost not possible for me to see the relevant differences between those two to make a decision. Regretably, I did not find measures taken under angle. While the frequence script under 0° looks fine to me, I doubt that there might be quite some beaming, given that diameter?

Hi Till,
you won't get rid of me - wherever you go
But I try to be helpful, nevertheless. To me the main difference between those two Beymas is the much more open back of the Neo driver. This would be a factor when the baffle becomes small.
To read some beaming measurements, look for this variety of 8" Visaton drivers:





You'll find the driver types in the picture adress info. Even in 8" drivers beaming is considerable at 2 kHz. So I would clearly refrain from 10" drivers for a dipole application.

Before looking further into it, I need to know whether there is a fixed baffle width and whether in this project constant directivity will be an issue to consider at all.

Neo10 would be an option, of course. But the Neo3 is no match to the AMTs mentioned.

Rudolf

[scorpion]

Till,

Even bass choice is difficult for OB. I think that the PD device is a bit limited in X-max for the kind of EQ that you will need. I would (if AE IB15 is not available) go for AE TD15X or TD15H for real good bass. Good bass doesn't come cheap.

18Sound 6ND430 also is real good, I know, I use it. I cross it 48 db/oct at 277 Hz on a 20 cm wide baffle and have no need to EQ for level response.

Thanks, Jeff, I see that MJAO is still going strong.

/Erling

[studiotech]

Since you mention jazz and classical, I would vote Neo10 all the way!  You will not be disappointed with its output.  I would not run it any lower than 300hz and a steep xover.  Look in the "driver' section on HTguide.com mission possible for my measurements and Zaphs site for his too.  If rock or pop were more of a concern, then maybe the 18 Sound 6ND430.

Rick, nice looking new baffles.  How many layers is that?  All MDF/HDF?  Are you gonna make a thread for them?

Greg

[Ric Schultz]

3 layers of double refined MDF with Green Glue in between each layer.  There will be a brace in the rear using layered 13 ply that attaches to the magnets of both servo woofers and to the baffle and base.  Since it will be a commercial thang I will have to post all info in the Industry ads and news forums.....and of course, on my site.  I have tons of ideas so this is just one of the possibilities....basically will be making anything imaginable.....as long as it is open baffle.  I have a great woodworker and also can use the CNC guy locally too.  I have a little preview info off my latest news page.

[studiotech]

Till, I just realized that you are considering the Beyma TPL150.  I might be one of the only people around to have used both it AND the Raal 140-15.  I recommend the Raal over the TPL.   It just sounds 'right' and never harsh even with bright recordings.  On good recordings it just floats.  The TPL is excellent, but never has that airy, disappearing act type of sound.  We use the TPL in our studio main monitors and there are finer details that we never hear clearly at the studio that just are plain as day on the Raals.  We have a reference disc compilation that we use for tuning systems and demoing gear.  After setting up my system at home, we heard some distortion on a few vocal tracks that we never heard on any other system.  It took the Raals to resolve this low level detail.  At first I thought it WAS the Raal distorting.  Only other place I've heard it clearly is on a set of Stax headphones. 

You know, I've got a pair left over from my last order with Alexander I could sell you for a very fair price, but I see you are in Germany.  Too bad.  Anyone else on here want a shot at the pair, message me.

Greg

[Ric Schultz]

Greg,
Did you use the Horn version of the Beyma?  And did you remove the back and let it run dipole?  Suppose to sound much more detailed and open without the constricting air pressure behind the driver.  This is one of the main reasons box speakers somtimes do not capture the magic/micro details.....the driver is always fighting the compressed air behind it.  I have removed the back of a cheap $30 Vifa tweeter and it sounded the same as a $300 Esotar after modding.  Danny Ritchie has removed the back off the compression driver on his V-1 to good effect and now the Hawthorne Audio guys are going crazy after doing the same to their compression driver on their coax.  Let it breath!  Open Baffle and open backs forever!  Open minds and hearts too! 

[studiotech]

No, we were not able to run it with the back off due to the nature of the speaker, but I wish now that I had made a larger rear chamber for it and stuffed it with some Bonded Logic rather than the thin material that is in there from the factory.  Unfortunately, there is a brace near the back of the driver and to do anything about it would require major surgery and removal of the speakers from their mounts in the studio.  Neither an easy, quick task.  If I ever work with the Beyma again, I will remove the rear cup for sure and make a chamber for it to live in.

Greg

[THWO]

Whow, thank you all for your support and good ideas! Sorry for answering late, I have been "en route"...

Greg, I love the design you did and I am very attrackted to trying something similar. However, I´d prefer  "full service" of a woofer(s) over setting a separate subwoofer which would not fit well into the overall arrangement in our living room. As I learnt from your thread, you used the RAAL as a monopole only, right, not as dipole? Do you miss anything or do you sense sort of acoustical non-symmetry as the treble is not radiated to the rear? Probably not as you wrote that you are not too keen on rear radiation in the first place...

Thanks for your pic, Jeff. Looks very nice, but I admit I would (as per today) prefer som larger mids...

Hi Glen, interesting that you went back to one 18" only. What driver did you choose for that? Other people say that just one 18" maight be not really sufficient, but you seem to be happy and that´s an important statement. One woofer would make design considerations much easier. The dimensions of your baffle, especially it´s width, seem to correspond well with my own considerations.

Ric,

"two Neos should rock you till the cows come home"

that really rocked me!  -  I am still giggling... And you presented me quit a to do list as well, thankls for that. As I am on design as well, I still am not too convinced that I like H-frames although they seem to work really well. Two 12" might be another idea as well as they show almost the same surface area as one 18" but may eventually be more accurate with their separate (two) motors. However, one good 18" with sufficient Xmax and "fast" suspension could bring lots of joy as well... Hmmm.

Hi Rudolf, it´s always great to meet you here and there, and thanks for your patience with me and that I still did not manage to get you tired of helping me out
I admit that constant directivity is not necessarily my main concern. Of course I´d like to enjoy a sweet spot being not too sweet (narrow), but a range of approx. three feet on a listening distance of about 14 feet from the speakers without heavy disturbances in the overall frequency script would already be more than I can ask for. A baffle width of 18 inch and height of 50 inch would be perfect. If I had to go two inches higher, I can get used to that. But everey bit wider would really hurt my eye. Going active plus DSP will certainly be a conditio sine qua non (as the French say), to make it right.

Erling, thanks for you answer, too. I know that you are very satisfied with the IB15. I admit that I am not too convinced about the AE Dipole 15 or Dipole 12, looking at its high QES and QTS. Although seemingly very good in deep bass, I don´t know how "fast" (accurate?) they are in the upper bass / low mid. Although I have to admit that I judge from the specs only and that I did not here `em in person. I may be wrong...

Greg, I am very impressed about your detailed description of the RAAL 140-15. However, having a look at its sticker price makes me swet a bit. No chance to set two of them i.e. side by side or back to back to create a dipole here. Thanks for your offer selling me a pair at a fair price. I might very well be interested in the moment the choice of drivers is set. Leaving the question to shipping cost to Germany and guarantee service... But it sounds very inviting. Would you be ready to send me a qutation by email sometime?

Looking forward to continuing the discussion, although I know that I still have to keep on selecting - and finally deciding...


Regards
Till

Edit:  Sorry, correction: Listening distance is about 11 feet, not 14...

[studiotech]

Till, you are correct, only monopole for this particular Raal, BUT there is a dipole version now!  Just make sure you are sitting down before you see the price.

I like to absorb most of the rear wave, as a full dipole is too live for my tastes, so monopole Raal is OK for me.  I use the 4" Bonded Logic directly behind the Neo10.  Additionally, I have a good amount of absorption panels behind the baffles which are approximately 5ft from the rear wall.

The dipole 15 will suprise you with the amount of deep bass on a small baffle.  It really does not require a large amount of EQ to get btw 20-30 Hz.  There is always the 2nd coil too that you can attach a VR across and play with the tuning.  You could also ask to get a custom version with lower QTS if you pester John at AE.

Looking forward to see what you end up with...

Greg

[THWO]

Greg, thanks for your opinion on the dipole 15 regarding reproduction of deep bass. However, I vaguely recall somebody having written about the same driver:
"Dipole 15 are out because even though they played very low with minimal EQ, I was not pleased with above 50hz performance.  Maybe it was just me, but I could never get them to sound pitch defined in their uper register.  I don't know if the high Q of the driver gives this effect or not. "
Well, but this is exactly what I am looking for: Precise, dynamic ("dry") bass and not a wet towel. Response in the 20´s is less important to me as I don´t like permanent "subsonic" fluttering and mulmy pressure on the ear regardless what I am listening to.

Yepp, the dipole version of the RAAL shows a whopper of a price tag. And it is uuuugly, too! Once I´ll be going to start the project (guess I should make an appointment with my bankers, first, or sell all the other stuff...) I should begin with a test baffle. Then I can play with absoption materials on the back side as well and see what happens...

Regards
Till

[scorpion]

Certainly, Purposely IB15 or not, but then TD15X or TD15H would be among the real bests to pay for, certainly.
Regarding !8Sound  6ND430 I suppose that Greg just wanted to show power bests, No doubt that Classical also sounds very clear with the 6ND430.

/Erling

[JohnR]

FWIW, I run dipole 15s from 80 to 800 Hz... however I don't have the luxury of trying multiple drivers with the same task.

In Europe surely drivers from PHL, 18sound etc are readily available? I have a heard a system using PHL (18, 10, 6) and it sounds very good. (Not OB)

[THWO]

Meanwhile I have found a woofer with figures and response so good I barely dare to beleave:  Precision Device DP.1550
I made a scan of the datasheet => 

Looks like this could be a nice one for a system with only one woofer instead of two per side? And EUR 200 seem well OK...
What do you wonderful people think about it and does anyone enjoy any own experience with it or other 15" PDs?

Regards
Till