SEOS / Dayton 2 way

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Mindsource's first build - SEOS / Dayton 2 way

Ok so I finally did it.

Denovo Audio SEOS-12 Waveguide 2/3 Bolt Matte with 1-3/8"-18 TPI Adapter

Dayton Audio D250P-8 1" Polyimide Compression Horn Driver

https://www.parts-express.com/dayton-audio-ds315-8-12-designer-series-woofer-speaker--295-434

It will be a sealed enclosure, active crossover/dsp, bi-amped with class D 50w x 4.

DSP will be JRiver and Asus Xonar Essence 7.1

Drivers will be here early January, I will start modeling the enclosures in autocad over the next little while. Everything will be laser cut or cnc so I can get very precise. I guess I will use 3/4 mdf cld box in a box. Not sure what to use for cld, green glue?

Thinking the front of the cabinets will have a flange that will go flush into a baffle wall in the front corners of the room. With ample toe in.

What mic should I get for measuring? I'm on a budget.

Gotta track down some 30ppi reticulated foam here in Canada for a good price too.

This project will take a while. This should be fun.
 
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Cool project! Are you choosing the "hi-fi" woofer for low end extension?

For the mic I'd recommend a professionally calibrated unit rather than a "factory" calibrated mic. It's more expensive but you might as well do it right the first time. I got mine from Cross-Spectrum here in the US. I'm not sure where you'd source the foam in Canada. The best source I've found is here in the US and is actually local to me. He imports it from Germany. I'd say worry about getting a good xo designed before you start playing with the foam.
 
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I got my UMIK-1 from Cross Spectrum Labs too. It is a calibrated relative to itself but does not have absolute cal. You need an SPL meter to calibrate the gain. Also, the default gain was too high and I had to open it to adjust the dip switch to lower gain. Good mic though. Does this mean you are not doing the Trynergy then?
 
Nate - I'm choosing that woofer because it seems like the best budget 12" for a sealed cabinet. Sticking with 12" to match the dispersion of the SEOS-12. Yes I'm interested to know how low it can go.

I think I will take both of your advice and go for that umik from Cross Spectrum Labs.

X - It does mean I'm not going Trynergy. I probably would have built one by now had PE not given me such a run around. After some thought and consult I'm going to cut my teeth on this project. It's simpler to construct, a tried and true design. I will still be watching with interest on how you tackle the HF dispersion on the Tryngergy.
 
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I am curious on how you will like the Dayton driver. From the description it is being compared to the B&C DE250. I have considered building using the same components except using the more efficient Dayton pro woofer.

Dayton Audio PA310-8 12" Pro Woofer

I went to horns 30 years ago and I have never looked back. As for how low it will go, that is what subs are for. It will go low enough for most. My LaScala's start dropping around 90hz but the bass it does make is fantastic being horn loaded and is good enough for me and if I want more low bass I turn on my sub of which I rarely use. It is a personal taste kind of thing.
 
Mhm, That Dayton Pro is what was originally recommended to me. But with the poor conversion from CAD to USD I had to stop the bleeding somewhere. All together these drivers costed me over $100 more just because of the low Canadian Dollar :eek: I got them in a hurry because PE botched my last order so bad that I was able to convince them to give me free shipping on this one. Which would have been almost $250 CAD!!. ouch.

Anyways I will be exited to see how these compression drivers work too. If they are what they say they are then I see it as a pretty good investment. I can cut my teeth with this and as the pioneers here start fine tuning DIY Synergy's then one day I should have a good start to one.
 
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I know you got the drivers already now so good luck. What happened with the PE order that messed up your Trynergy plans? That's too bad because the Trynergy sounds better than a compression driver in a waveguide. If you are sensitive to harmonic distortion - there is a very noticeable difference between -25dB HD and -55dB HD.

FWIW, PRV's D280Ti is fairly priced and an excellent performer worth looking into.
 
Indeed it does. I will stick with a sealed cab though.

Can anyone more experienced than me look at this graph and point out likely breakup frequencies?


First breakup of the woofer is at 700Hz....there's other breakup modes at 1kHz, 1.8kHz and 2.5kHz.

Look for wiggles in the impedance response first...then look for the corresponding dips and peaks in the frequency response.

Using a driver through the band where the wiggles are happens all the time...so don't panic about that...just remember that the graph won't necessarily tell you how audible they are.
 
So...I've used the Seos 12 waveguide with both the Dayton compression driver, and a PRV D290 compression driver. It can be a very good performer, but do be careful of harmonic and intermodulation distortion at lower frequencies with that waveguide.

The Dayton compression driver is fantastic in a horn which provides quite a bit of acoustical load, like an exponential flare or even a Danley Paraline. The PRV is a bit more forgiving, it's a beefier driver overall...but it had issues with the SEOS flare as well and I ended up having to cross over higher than I would have liked.

Perception wise the distortion sounds like a muddying and harshness to tenor male voices and instruments in that range.

I was doing a passive crossover, so your active crossover/DSP solution will have a lot more options in fixing the issues.

I would get a uMik-1 and use REW for the measurements. (It's what I use.) When you've got your system and you're testing crossovers do distortion sweeps both on and off axis....and run some multi-tone tests with two closely spaced tones just above your crossover frequency.

Attached are pictures of my two most recent "big" horns. The first is a Smith horn using a Dayton compression driver (bolt on) with a smith horn using an exponential (ish) flare. Crossover on those is~ 2kHz. The second is a SEOS two way with a FaitalPRO woofer and a PRVD290 driver. Crossover on those was 2.8kHz.

Scott
 

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From what I get from what you are saying about the Dayton driver is that this cheap Dayton horn would be a better choice or something similar.

Dayton Audio H812 1" Exponential Horn 100x60 2-Bolt

Depends on use....not sure I'd use that for hi-fi...PA yes...but likely not Hi-Fi. I'd look at FaitalPRO STH100 1" 80 x 70 Elliptical Tractrix Horn 2-Bolt if you want a better LF loading horn with many of the same low diffraction concepts of the SEOS. I've got the 102 version and it tests so well with the D290 that I'm thinking of including it in my DIYRM-C design. (What that design is...I don't know fully yet.)

I have read different opinions of waveguide horns on the web.

Isn't that the truth. Sigh.
 
Audiophile vs. PA
Midbass vs. Woofer

Midbass:
-low Mms ~60 grams
-low Le between 0.2 - 0.6mH
-curve-linear cone with ~90 degree polar directivity at ~1200Hz
-treated/composite cone + triple-roll controls breakup until ~3Khz
-Fs ~40-50Hz
-Efficiency ~96db/watt

A 12" driver with "midbass" T/S parameters is typically selected for an Audophile SEOS_12 crossover at 1200Hz. Audiophile Econowave ~$250 for midbass+SESO12+compression driver

Your measurements and listening tests on this ~$150 SEOS12 Dayton design will help explore price vs. performance options.
 
Ok so I am cancelling the order because I just got the receipt and the import fees are more than the drivers. Luckily Solen here in Canada has a decent selection, and they have Dayton. I don't think they have much selection that competes with the Dayton products at the price, which is the top of my budget. Unless someone sees otherwise?

From what I seem to be gathering so far it seems this combo is worth investing in?
 
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Thanks a whole bunch everyone for the input.

The cost of this system is starting to catch up with me as I am looking at tuition and textbooks for this semester... I'm moving into a house and tbh I haven't had an actual stereo for years due to being apartment bound.

In Canada these stereo speakers are going to cost me at least $600 all said and done. A lot for a student budget, but I'm a fan of Toole / Geddes who both advocate for this type of speaker. Do you think these drivers make for a justifiable speaker at this price?

Would this driver be a better fit?
https://www.parts-express.com/dayton-audio-pa310-8-12-pro-woofer--295-032

Keep in mind I want to stick with a sealed enclosure.

Thnx
 
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Thanks a whole bunch everyone for the input.

The cost of this system is starting to catch up with me as I am looking at tuition and textbooks for this semester... I'm moving into a house and tbh I haven't had an actual stereo for years due to being apartment bound.

In Canada these stereo speakers are going to cost me at least $600 all said and done. A lot for a student budget, but I'm a fan of Toole / Geddes who both advocate for this type of speaker. Do you think these drivers make for a justifiable speaker at this price?

Would this driver be a better fit?
https://www.parts-express.com/dayton-audio-pa310-8-12-pro-woofer--295-032

Keep in mind I want to stick with a sealed enclosure.

Thnx

I made that recommendation earlier. It should do fine and I like the more efficiency of this one vs the one you picked out. I personally lean to Eminence woofers but for a student on a budget it should do great. You will not need to attenuate the horn as much.
 
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