Lowcost woofer with Supravox 215

gug42 · « **on:** 28 Jun 2018, 10:57 am »

Hello Evryone,

I'm starting my own project. Normally I will get some supravox 215 in the next few days. I'd like to discover the Open Baffle.
Supravox recommand the 285 GMF with 215 .... But they are expensive ... for just the low end (<200 Hz).
For the first trial, I will be in active filtering and multi-amplification. But one day i will like to move to passive to use only one amp

So well did you have some low cost recommendation 12" speakers ?

Thank you in advance

JohnR · « **Reply #1 on:** 28 Jun 2018, 04:00 pm »

12" is a bit small... Are you in Europe?

FullRangeMan · « **Reply #2 on:** 28 Jun 2018, 04:30 pm »

+1, 12'' is too small as OB.
There is no lowest cost than the Alpha 15A for OB,
or the DeltaLite II 2515 for a bass reflex 130L box
for stunning 99dB sensitivity, not a small feature
for a small tube amp.

MJK · « **Reply #3 on:** 28 Jun 2018, 04:54 pm »

There are many 12", 15", and an 18" high Qts with low fs woofers on the Parts Express web site from Eminence, Goldwood, and GRS. A pair of any of these per side should allow a passive OB speaker system to be designed. Configure as W-FR-W or W-W-FR as desired.

Try using BASTA from Tolvan Research (Google is your friend) to design the baffle size and shape, the driver layout, and the passive or active filters. It is not that hard and should perform as expected if you use measured T/S parameters as inputs.

gug42 · « **Reply #4 on:** 28 Jun 2018, 05:55 pm »

Hello Evryone,

Thank you for your answer

@JohnR : I'm in Europe, France. Hum .... I was hopping one (or two) low cost 12" could done it

@FullRangeMan : one or two Alpha 15 for this sensitivy ?

@Mjk : ok I will search in this database .... But well hard to know if the driver is good or bad ... I will search and come back with some references
A simulation software is a good thing, but I need a "start points" ...

Can I assume that the "W" is for Woofer and "FR" for full range ?

Thank you.

Regards,

JohnR · « **Reply #5 on:** 28 Jun 2018, 06:10 pm »

Maybe have a look here

https://www.thomann.de/intl/loudspeaker_12_inch.html?oa=pra

and here

https://www.thomann.de/intl/loudspeaker_15_inch.html?oa=prd

MJK · « **Reply #6 on:** 28 Jun 2018, 06:13 pm »

Code: [Select]

Can I assume that the "W" is for Woofer and "FR" for full range ?
That is correct.

FullRangeMan · « **Reply #7 on:** 28 Jun 2018, 11:05 pm »

Quote from: gug42 on 28 Jun 2018, 05:55 pm

: one or two Alpha 15 for this sensitivy ?

The sensitibity I mentioned is for 1 DeltaLite II 2515 in a BR box:
https://www.parts-express.com/eminence-deltalite-ii-2515-neo-15-speaker-driver--290-595
In OB it will loss about 4-5dB and QTS is low only 0.38
If you want cut it inductor is 4.7mH air core, avoid iron core.

FullRangeMan · « **Reply #8 on:** 29 Jun 2018, 12:07 am »

Quote from: MJK on 28 Jun 2018, 06:13 pm

Code: [Select]
Can I assume that the "W" is for Woofer and "FR" for full range ?
That is correct.

Hi Martin,
Do you think these 12 and 15 are suited as midrange in OB?
Thanks
https://wgsusa.com/BHHP#specs

https://wgsusa.com/g15a#specs

MJK · « **Reply #9 on:** 29 Jun 2018, 12:22 am »

Quote from: FullRangeMan on 29 Jun 2018, 12:07 am

Do you think these 12 and 15 are suited as midrange in OB?
Thanks
https://wgsusa.com/BHHP#specs

https://wgsusa.com/g15a#specs

I don't know, they are pretty big for a mid range driver and are quite expensive.

FullRangeMan · « **Reply #10 on:** 29 Jun 2018, 12:28 am »

Thanks, unfortunately Fs is too hi for a woofer.

gug42 · « **Reply #11 on:** 29 Jun 2018, 07:40 am »

Hello,

Thank you guys for your answer.
About the QTS and drivers spec, an really interesting point : the supravox 285 GMF, used in the supravox open baffle :
- QTS : 0,38 (I assume it's do to the large Frame)
- FS : 47 Hz
- Mms : 20 g ! (Whaou really light !)
- Xmax : +/- 4mm
- Vas : 150L

Can I assume I can search something close to thoses specs, perhaps with a little more QTS ?

Regards,

MJK · « **Reply #12 on:** 29 Jun 2018, 11:03 am »

Quote

Can I assume I can search something close to thoses specs, perhaps with a little more QTS ?

I would not select a woofer with those specs. For a potentially passive OB speaker, I would look for a woofer with a Qts > 0.7 and preferably > 1.0 and an fs <= 40 Hz. The SPL/W/m for the woofer(s) should be 6 to 10 dB greater than the full range driver to produce a smooth flat response through the crossover to the lowest frequencies possible.

gug42 · « **Reply #13 on:** 29 Jun 2018, 12:28 pm »

Hello,

Thank you.
Interesting. Indeed supravox use their own speaker .... but why not build a "special" driver for this task .... ?
It will be very hard to have those specs for one driver ... Supravox 215 are around 96 dB /W /m ....

Buy the way I found the curve of the Apha 15A very hugly ... disapointing.

Regards,

gug42 · « **Reply #14 on:** 29 Jun 2018, 01:34 pm »

Hello,

About some 15" : any Opinion about some Fane ? SO15-400LF or FC152F01 ?
https://www.toutlehautparleur.com/media/catalog/product/datasheet/fane/SO15-400LF-8.pdf
https://www.fane-international.com/downloads/Fane-FC152F01-DS280417.pdf

About some 12" , only this one, and doesnt seems good as the 15"
https://www.fane-international.com/downloads/Fane-Sovereign-12250TC-DS240316.pdf

I could buy a pair of Fane 14 400LF for 200€ ... ?

Thank you in advance !

Bumpy · « **Reply #15 on:** 29 Jun 2018, 03:16 pm »

My advice would be to find drivers with similar sensitivity and impedance. Once you deviate from this you will need additional component in the crossovers and this is bad (resistors in particular).

Stuart · « **Reply #16 on:** 29 Jun 2018, 04:19 pm »

The Faital Pro 15PR400 would be my choice, it sounds just wonderful and is super clean past 2khz. It also sounds far better than the Eminence woofers mentioned here.

read this link. I use it in a 3 way of a different design and its just awesome. Volti Audio use it in their Vittora and Alura models

http://www.troelsgravesen.dk/OBL-15.htm

FullRangeMan · « **Reply #17 on:** 29 Jun 2018, 06:20 pm »

Quote from: Stuart on 29 Jun 2018, 04:19 pm

The Faital Pro 15PR400 would be my choice, it sounds just wonderful and is super clean past 2khz. It also sounds far better than the Eminence woofers mentioned here.

read this link. I use it in a 3 way of a different design and its just awesome. Volti Audio use it in their Vittora and Alura models

http://www.troelsgravesen.dk/OBL-15.htm

Thanks for inform, it really very linear.
Do you use this driver?
How it sound as mid range? (over 500Hz)

FullRangeMan · « **Reply #18 on:** 30 Jun 2018, 04:11 am »

There is two Beyma that are interesting:
http://www.usspeaker.com/beyma%2015P80Nd-1.htm

gug42 · « **Reply #19 on:** 1 Jul 2018, 07:07 pm »

Hello Evryone,

@Bumpy : Agree, very hard to find

@Stuart : Thank you. Seems clean. A bit too costly .... For the same price is it more usefull to go for a supravox 285 GMF ?
@FullRangeMan : Thank you, but, sorry, too expensive ... 400$

Any advice about this one ? http://audio.manualsonline.com/manuals/mfg/electrovoice/dl15x.html?p=1

On the paper I found the Fane FC152F01 to have lots of potentiel, isnt it ? For around 111€ ...

Thx