[FullRangeMan]

PureAudioProject OB-A15se (pushing the budget)
Monacor SP-382PA (Fs 25Hz)
Omnes Audio OBW 15PA

Since you will use DSP I would like to suggest Acoustic Elegance Dipole 15:
http://aespeakers.com/shop/dipole/dipole15/
and DeltaLite 2515:
https://www.parts-express.com/eminence-deltalite-ii-2515-neo-15-speaker-driver--290-595
OBS.: I was forgeting this very special driver with Hemp Cone and huge Neo magnet, I dont know its QTS though:
http://www.siegmundguitars.com/TTsuperman.html
If you managed to find its parameter please send me.

[nicoch]

OBS.: I was forgeting this very special driver with Hemp Cone and huge Neo magnet, I dont know its QTS though:
http://www.siegmundguitars.com/TTsuperman.html
If you managed to find its parameter please send me.

thanks nice info !
look like another 2515 derivate but is lower qts looking the graf..... fs is 32  10hz down, eff is little up 101.
He is 85db at 55hz vs 100 at 500hz

[FullRangeMan]

I suppose this Hemp driver rec use is BassReflex or vented, my personal preference in this case is not OB, I would use a BR box with one big duct facing side, not in front baffler as usual.
It worth to use in a hifi system due the special cone sound.
Using a BR box will not need DSP just a simple inductor.

[Fjendbo]

Sorry, my budget is/was EUR 135 per driver. I guess that equals to USD 100 when looking at US webshops, so the drivers from AEspeakers, Eminence and Seigmundguitars are too expensive.

Also, I have already bought the Dali's for USD 55 each. And if a sell the other drivers in the package it will be approx USD 37 each. Very different price.

[FullRangeMan]

At $135 per driver hard  to beat the usual Alpha15A.
https://www.parts-express.com/eminence-alpha-15a-15-driver--290-407
And it dont need a DSP just a quality inductor.

[AJinFLA]

Also, I have already bought the Dali's for USD 55 each.

Can't beat that price and they spec very similar to Dayton, other than xmax unknown, but probably similar given its a dedicated sub.
Bit difficult to read, but I didn't see any glitches in the impedance curve you posted, that might cause concern for your upper frequency limit.
I assume you will be measuring frequency responses in your baffles?

[nicoch]

At $135 per driver hard  to beat the usual Alpha15A.
https://www.parts-express.com/eminence-alpha-15a-15-driver--290-407
And it dont need a DSP just a quality inductor.

or the Beta 15 with a touch of dsp

[Fjendbo]

Can't beat that price and they spec very similar to Dayton, other than xmax unknown, but probably similar given its a dedicated sub.
Bit difficult to read, but I didn't see any glitches in the impedance curve you posted, that might cause concern for your upper frequency limit.
I assume you will be measuring frequency responses in your baffles?

I was positively surprised when I measured them. Didn't have my hopes high 
How is no glitches not a positive thing? I ask purely out of lack of knowledge.

And I will, of course, be measuring them.

Here's the impedance curve again. Hopefully a bit easier to read:

[Fjendbo]

[AJinFLA]

How is no glitches not a positive thing? I ask purely out of lack of knowledge.

It is positive. That's why I said seeing one might be cause for concern.
Thanks for expanded scale, it looks like there might be a small one at round 600hz, which will show up in the FR also, but quite mild. Nothing of concern.
I'm surprised also  . For a "subwoofer" driver that was to be used <200hz, it seems quite well behaved well up in frequency. Should be fine for your 700hz xo.

[lowtech]

I think you may find that crossing over a 15" woofer to a planar mid at 700Hz will likely yield an "interesting" polar response.  Whether or not you find this a problem will depend on your expectations, listening configuration, etc.

[Fjendbo]

It is positive. That's why I said seeing one might be cause for concern.
Thanks for expanded scale, it looks like there might be a small one at round 600hz, which will show up in the FR also, but quite mild. Nothing of concern.
I'm surprised also  . For a "subwoofer" driver that was to be used <200hz, it seems quite well behaved well up in frequency. Should be fine for your 700hz xo.

Ah okay. After re-reading your sentence, I understand
It added to my surprise because when the Dali S1.5 was on the market, it wasn't that expensive for a 15" inch subwoofer. DKK 8000 which probably translates to USD 750-850. And in addition to that, I also imagined it to be a "just good enough for the application"-driver if you understand? Since it's OEM/produced especially for Dali.

Well, I'm happy I took the chance with these drivers, although no real measurements have been done yet. And the lower price leaves some space in the budget for unforeseen expenses as I'm sure they will come.


lowtech
Yes, maybe so. However, I'm still inexperienced, so I do not have much to compare with and, therefore, I'm sure I will have a positive experience

[Fjendbo]

Time to continue

I may have an opportunity to get woodworking this weekend. Currently living in an apartment so I'm only able to build when I'm at my parents and parents in law.

Regarding the design, I got permission from the girlfriend to be inspired by studiotech's project: http://www.audiocircle.com/index.php?topic=85662.120. A simple baffle with a simple stand.

To the baffle, my current plan is MDF - rubber cork - MDF - rubber cork - MDF. MDF will be 22mm and rubber cork 2mm. All glued together with a strong, dampening glue. I've done some searching about rubber cork used as baffle dampening, but haven't found much. Is rubber cork between MDF a bad idea? If yes, any better materials at the same price point?

In relation to the baffle is speaker mounting. I do prefer no visible screws on the front which means mounting from the back like Hawthorne Audio did on many of their speakers. Nice clean look . Although I also plan to make a fabric cover.
My concerns about mounting are vibrations, weakening the baffle, separating acoustic centers more than necessary and making waveguides for the planar drivers by hand (no CNC) on front and back. Any advice regarding materials and build are more than welcome!

Below is a quick visual mockup using cardboard and Word copy/paste



No ideal placement for the right speaker so close to the side wall but that's the situation right now.

[Fjendbo]

I have ordered rubber cork. We'll see how it turns out.

[JohnR]

Cool. I'll be interested to hear how the layered construction works out. I'd suggest building and measuring a simple (construcvtion wise) prototype first.

[Fjendbo]

Hi,

I found an add with some rather cheap used Neo8 drivers today. Would you guys recommend 4xNeo8 pr. side or 2x.Neo8 and 1xNeo3 as I have planned right now?

[JohnR]

You may find horizontal directivity a bit limited with just the Neo8s. You could try it with the four you already have (mono) and see.

[Fjendbo]

Yes. I have ditched the idea again. All systems I have seen with Neo8 as tweeters have been in tall line source speakers.

Another question - which I, of course, can test and measure when I get the chance - but will your experience recommend running the speaker as a 3½ way letting lower placed 15" play as a subwoofer to avoid floor bounce effect of voices? And only let the higher placed 15" play up to the crossing frequency with Neo8.

[tubesaab]

Hello Fjendbo

Can see you will use neo 8 with a filter around 700hz....they can sound a bit thin with that low frequency.

i have a line array with 9 neo8..and use a filter 12db from 850hz

i have tried with a groundsound digital  filter  to use down to 600hz,,,but get the best sound around 850hz

it sound interesting the system you are going to make , i think you have to make sure the 15inch woofer are fast in the high area,,so it reach the neo8 in a good way

Best Regards Bjarne

[Fjendbo]

Hi Bjarne,

Thank you for sharing your experience!

I believe the crossover frequency between the woofers and Neo8's will be the trickiest so any recommendations on that matter is appreciated