Hey guys...we need a little rallying here... - Page 129

That is great news Erich!

Actually I was just referring to "inexpensive" (cheap!) speakers and agree with you wholeheartedly that the mid-to-high end speakers have improved. However, it seems like prices have exploded in this upper range, too.


See above.


I'm not enough of an expert to know how multiple smaller drivers vs one larger driver really affects our perceptions of. Would be so fun to be the listener in double-blind tests and see if we could perceive a difference or not, wouldn't it?


Heh heh...I've been thinking about the Phils as well (though not certain which model yet) AND building a SEOS of some type, too! I'm sure many of us would just LOVE to hear your comparison of the two once you're up and running.


Makes sense. I've seen the SEOS waveguides designs in that forum. I don't specifically see one for the Eminence Delta12, though. Did you mean the Designer12?

Some questions:

• How do you all decide which size SEOS and woofer to get?
• Where can the compression drivers be found/purchased? (The SEOS is just the waveguide, correct? That is, it doesn't include a compression driver with it, right?)
• Do you feel it's worth building one of the completed designs like the SEOS12 with Designer12 woofer that is amazingly inexpensive given what the quality of sound will be (I think!) or would it be worth it to wait for awhile until a few more designs are out there, particularly ones that use a higher quality woofer and compression driver to get absolute top notch sound?
• Do all the designs on the DIY Sound Group forum include plans for the baffle/enclosure? I guess I'm a little confused on what information is included when plans for a specific speaker build are posted. (After a month of reading, this newbie's on information overload! )

Pianoman-

To answer your bullet points:

Go with the SEOS-12. It is going to make up the majority of the designs and is the most reasonably priced. It can be used with a 12" or 15" driver. Going the 12" route is generally a little cheaper since the crossover point will be a tad higher and the driver is a tad cheaper. The difference in performance will be small and only likely only detectable in a blind test. Even the relatively cheap Delta12 or Designer12 designs are leaps beyond the Klipsch RF series, IMO.

As far as the compression driver, I believe Bill was using the B&C DE250 which is reasonably priced (for a CD) and easy to get. Erich H is in the process of putting together his own CD offering that will be similar to the DE250 but cheaper (and maybe a better performer, but pretty damn similar). Just go with whatever CD the designer used. The differences between the best 1" exit CD's is small.

From where you are starting, I'd suggest jumping in with either the Designer12 or Delta12 designs by Bwaslo. They don't employ uber-woofers but they will seem like uber woofers compared to what you are used to. Down the road you could easily swap in some AE TD12's or other highend woofer. You would need to alter the crossover but that isn't a big deal. The DE250/SEOS-12 combo wouldn't need to change.

For the enclosure, at a high level it doesn't really matter. We are talking about very wide baffles to start with so you don't have significant baffle step issues like you do with 5-6" wide baffles. Generally people will build the cabinet about .5"-1.5" wider than the widest component (woofer or CD). Either leave a sharp corner, roundover or bevel, it is your call. The audible effect is debatable.

For enclosure volume and tuning, I'd suggest asking Bwaslo what he did for the design you are using. Generally, I suggest going with a ported design and leaving the option to plug the port. Then you can try either alignment and see which gives you the best integration with your room and subwoofer system.

BTW, you will need some sort of subwoofer(s) IMO. Some of these woofers can do OK down to about 35-40hz, but it is less than ideal and certainly not good enough for HT duty. Beyond that, using satellite subs has an overwhelming count of benefits over full range mains.

Bottom line, build one of Bwaslo's two designs, you will love it.

Thanks for this post coctosta, it applies to me as well.

No problem. The best route for most people, especially beginners and/or budget minded, is to simply go with an existing design that uses the SEOS-12/DE250-or-clone and a less expensive woofer. Bwaslo's designs should work great for most people.

The performance gains by going to a 15" woofer, SEOS-15, higher end woofer, DSP, etc are all fairly small. The "make or break" part is the crossover and Bwaslo has done a fine job with that. I can assure anyone that lesser components well-implemented will beat superior components poorly implemented.

Of course, some people simply want to learn and experience the crossover design part of DIY speakers. For those people, there is more freedom, but they are also responsible for the outcome and it will take some work.

At some point, when the AE group buy orders show up, there will be more designs using higher-end drivers and larger SEOS like the 15 and 18. Those will be at least 2x the price of the SEOS-12 Designer12 design.

I am looking at the designer 12s and the Malcolm. Can not wait to get rid of my Polk monitor 70s!

As far as inexpensive speakers go, I've been decently impressed by the EMP E55ti speakers, as long as you've got subwoofers to carry the low end and don't need the end-all in resolution. I think they have a very balanced sound.

But i'd say it goes like this

up to 400 dollars invested - commercial speakers win
~400 - ~2k dollars invested - DIY wins
More than that - it depends on the individual designs, but commercial speakers to start to have an edge again in terms of R&D and available parts.



It depends on the frequency range being covered. At low enough frequencies both will be a point source with the same aspects of distortion and output, etc, although the multiple smaller drivers will probably have more heatsinking area and thinner baffle. the higher up you go in frequency with these drivers, the more it starts to matter. THen you start getting into quasi-line sources and narrowing directivity, and even center to center spacing at the crossover - which is certainly relevant to us (IE look at the Malcom design).


I'm getting Phil 2s... raal tweter, neo 8 midrange, and better efficiency than the phil 3s.


No, i meant the delta12 - http://www.diysoundgroup.com/forum/index.php?topic=9.0


Well first of all, you pick an upper bandwidth for the tweeter section. a small diapgram compression tweeter can cover the top octave with the least amount of breakup and the most extension, but will probably start to struggle below 2khz. A more typical compression driver can play down to around 900hz, although you might trade some of that top octave out. a 1.4 inch or larger compression tweeter will certainly trade that top octave out, and probably need a super tweeter if you care about the top octave. These very large drivers can play even lower - some even going down to 500hz.

I decided to go with the 1" compression tweeter, because of the same reasons as Geddes and his speakers. I want directivity control down to about 1khz at the very least, as that's where timing cues, not level cues, affect perception of imaging. This is also based on the success of Geddes' Abbey and Summa speakers. I don't know about others, but at least a few of us are inspired by his work and decision making.

Now for a crossover point around there, you need a waveguide that can hold directivity down that low. That seems to leave the seos 12 and the seos 15.

to mate to a 12" waveguide, you probably want, give or take, a 10" woofer at around 1.1khz or a 12" woofer at around 950hz. this ensures a smooth transition in off-axis response.

to mate to a 15" waveguide, you probably want the 12" woofer covering up to around 950hz or a 15" woofer around 850hz.

I personally went with a 15" woofer, so I am waiting on the poured SEOS-15s. If you can live with the size, I think the 15" two-way is the ultimate choice from a directivity control perspective. The 12" two-way probably has slightly better power handling for the tweeter, but i'm not sure it matters in a home speaker.

the 1" compression drivers can't take advantage of the 18" waveguides, so bear that in mind. the 10" and 8" waveguides can't quite get the "full effect" of constant directivity.


Yes. However the SEOS waveguides were specfically designed with an entry angle to match the exit angle of two compression drivers - the B&C De250 and BMS 4550 - this ensures a smooth transition of sound waves. The de250 can be had from parts express, and the BMS can be had from the bms distrubutor directly. However these is also the custom drivers Erich has put effort and money into just for us, and I would give those serious consideration.

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The tweeter in that design is fine - it's the same one Geddes uses in his Summa and Abbey speakers - the De250.

But yes, I feel that high end speakers need, among other things, is careful control of flux modulation, and what i saw of the designer series drivers is that they make no effort in that regard. I would want a woofer driver with shorting rings. I went and ordered the Acoustic Elegance TD15M, which has a big copper sleeve on the pole piece as well as a shorting ring (the Apollo upgrade takes it a step further, but i'm not sure that matters in a home environment. if it could fund a comparision, i'd love to)

I don't think you need to go all out with an AE driver but the flux modulation IMO is significant. I also think the SEOS-12 holds pattern down perfectly well enough.


No, as they've been designed in make-shift test boxes.

I received a phone call from US Customs today. Everything has cleared okay.

Still haven't been given the total on all the fees yet. I guess it all gets added in with the shipping charges. Or in other words, the shipper will now tack on some more money just for fun........and I won't know the real amount.

I have been very happy with my SEOS waveguides - IMO they measures, integrates and sounds very nice and I think they are beautifully made. However, I feel the potential of the largest ones could have been even better released if allowed for larger drivers than the 1"-ers.

Personally I would love to have the SEOS 18 (especially this one) and 15 with 1,4" throat (Radian 951Be / ~0º exit angle). If possible I would also like to have the SEOS 18 for 1.5" JBL 2447 (unfortunately I don't know the exit angle of this one).

I feel confident that such WG's can be made available, but then the interest must be high enough for Autotech to make a mold.
I would therefore recommend anyone interested (it is not a commitment to buy) to leave jzgaja a thumbs up at his group buy thread on diyaudio.com Wanted SEOS size, throat dia and throat angles would be appreciated.

Cheers

I read through the whole thread and couldn't tell if a vector version of the SEOS logo was ever made. If not, I did a trace and outline version of the logo.

EPS format. Download and unzip (uncompress) to view. Good luck with your project. :-)

http://www.rwkstudios.com/avs/seos-vector-outlines.zip

I believe Bill's measurements showed that for the SEOS-12, optimal directivity matches are obtained at 1300 Hz with a 12" woofer and 900 (or maybe it was 950) Hz with a 15".

IMO, the 1.4/1.5" exit drivers are best utilized with 20-24" wide SEOS WGs. I believe Jzagaja has modeled some larger SEOS for 1.4/1.5" exits but I'm not sure what the status is on production.

The advantage of the 1.4/1.5" exit is that most of those can play as low as 500hz. The SEOS-18 holds pattern down to about 750-800hz. The downsides to a larger exit CD like worse 10khz+ response and directivity and higher price IMO outweigh the small benefit of using an 700-750hz cross when an 800-850hz can be achieved with some 1" CDs (DE250 comes to mind).

I'm not familiar with the Radian 951Be. I don't see it on their website. Is that a beryllium diaphragm 1.4" exit CD?

Generally speaking, a 15" woofer has an effective piston diameter of 13.5" which is the wavelength of a 1000hz wave. Theoretically, that is the point where pattern should collapse to 90deg (-6db point). Of course this varies from driver to driver. A 12" driver is around 1300hz.

In my experience the real world range is from about 900-1200hz for a 15" woofers and about 1200-1500hz for 12" woofers. There are many factors to balance of course when you are designing a speaker so YMMV.

Edit: I forgot to include that IMO the SEOS-12 is good down to about 1100hz and the SEOS-15 good down to 900-950hz. There is probably some play there. The SEOS-12 can be used with most 15" woofers but like with anything it needs to be measured and tested to be certain.

I do not disagree with you, but my experience so far is that I have got better results with larger format drivers when using them towards and below 1kHz than with 1" drivers. Must add that I think the DE250 is very good and can be pushed very low, which they have proven on my SEOS15 and SEOS18. But sonically they are IMO not on par with a pair of excellent 1,4"/1,5" drivers.

SEOS 20-24" will of course utilize a large format driver's potential better, but in my opinion these beasty waveguides simply get too large to fit into a normal living room. Ok, 20-21" could work but that's the ultimate limit for me personally. Also I struggle to find good reasons for using SEOS 20-24" unless paired with some enormously large midbasses to maintain controlled power response - I could be wrong here.
jzagaja presented a SEOS24 and also an EOS30 but I don't believe he will make any mold unless he receives some feedback.

The 951 is the 950 with 1,4" exit and can be found at behringer-electric.de. It is with the TrueExtent diaphragm. I haven't missed super tweeters on these so far.

I agree. I can't imagine going bigger than the SEOS-18 in a living room and that would require a pretty large room to not look odd. My ultimate performance speakers are behind a screenwall so I don't have size concerns.

I wonder if the results you are getting are more a function of the exceptional Truextent diaphragms. Have you tried the 951Be with the 18Sound XT1464?

I use JBL 2452H-SL's and I've thought about trying some Truextents but I just don't feel like spending the money. I've actually thought about trying some Radian diaphragms in some 2447's that I have.

I believe the beryllium is the reason for the incredibly smooth, detailed and extended linear response. What surprised me (and this is my audible perception) is the amount of energy that the large format driver releases in the upper mid. I don't believe that has anything particularily to do with the Be-diaphragm but more the capacity of the format, at least I have no other explanation - one must really try it to see what I mean.
Although expensive, the investment have definitely been worth it to me.

Radian recommends the driver to be used 800Hz up, which corresponds well to my experience so far. I haven't tried the 18Sound XT1464, But I will test the EOS15 in near future - it's just a matter of availabe time. However, I did a test on the XT1086 (a clone really) together with SEOS15 (SEOS12 would be a better comparison). Although XT1086 is very competent, I prefered the SEOS. The SEOS is simply an incredably good perfomer.

I also do have the JBL 2447 with its original diaphragms and my intention was to buy EOS15 for these as well to do direct comparison to the Radian.

and... I envy everyone that have a dedicated room to play in

Tytte71, are you from Norway?

A few people asked about shipping the SEOS there so I'll be looking for the cheapest way once I can package some up.

Hi Erich! Yes Norway it is.
Thanks for the info, I'll inform about this on the forum(s)... I believe there are many over the sea interested in particularily the plastic SEOS12.
A short update on your exiting CD projects would also be appreciated

The CD project should be here in about 1 week if everything goes well.

I only have a shipping account with FedEx. Rates are good for inside the USA, but not international shipping. The best way for international has been with the US Postal Service.

But I don't have an account with the US Postal Service yet. So my website can not figure shipping charges for other countries. Of course I do not think it's a good idea for people to order something if there is no way to figure how much shipping will be. That is why members from other countries can not place an order yet.

I will do my best to package things very well in the smallest box sizes, then get international shipping rates. Some countries are okay, others are very high.

Thanks again! I am really looking forward to see the new driver available on stock. If preordering is possible, you can count me in.

Thank you very much for your help.

I can't actually view it on my computer, but I'm going to send this to a lady friend that has a Mac and works with graphic design. I'll keep you posted.

We want emblems, We want
emblems! (stomps feet)

...
.
---
...

(repeat)

I saved it back to Illustrator CS2 or higher. If you need any other file formats, (.ai, .png, .jpg, .pdf, etc.) just say the word. Thanks!

:-)

I think he wanted to use it for tracing sheets? So it would need to go into a pdf, so i think .eps makes the most sense.

tytte... you're making me want that seos-18 + Radian 951Be combo.... real bad

Do you have a link to something I could look at?

I'm trying to think of something to do for the people that pre-ordered, but not sure if there's enough time to get anything really neat made up.

Here's a quick conversion I did in Photoshop so you can get the idea.

For reasons I won't go into right now, I'm also interested in a two-way SEOS with a 1.4" CD. Now keep in mind I'm a newbie and don't really know what the heck I'm talking about yet! But, I found somewhere on some horn thread sometime in the past day or two something about (heh heh...somebody's having some fun now) the FaitalPRO HF14AT 1.4" compression driver being in his opinion a fantastic CD to use because of its very flat FR over a wide frequency range plus its ability to play quite low (500Hz - recommended crossover 900Hz). He had been recommending the FaitalPRO HF20AT 2" CD until the 1.4 hit the market.

I've looked up many of the CDs recommended by various builders on several sites and I must say the FR graph of the HF14AT on the FaitalPRO website does look very, very impressive. Probably the best I've seen out there in something that can play this low.

Now here's where my novice status comes in. It's my understanding that with the larger diaphragm CDs, often the FR above 8kHz or so can get quite rough, and that there is usually a drop off in the high end that needs to be compensated for in the crossover. I guess the HF14AT exhibits much less fluctuation than most at the top end, as well as considerably less drop off than most. This means that less compensation would be needed in the crossover circuit to boost the high end back up, correct? That's a good thing, right?

I would particularly appreciate any opinions you all have about this driver and its possible use with a SEOS waveguide. Would there need to be a new SEOS waveguide designed specifically for this driver in order to actually use it in a build? Or does something already exist that it could properly be used with? Thanks.

I'm truly sorry