[tino84]

Hi, I've searched around the forum, but maybe nobody knows those woofers,or maybe they are marked under another firm.

http://www.conrad.com/Dyh-1220-Speaker-12-Inch.htm?websale7=conrad-int&pi=329460&ci=SHOP_AREA_22500_1312038

there is also 15" version.

it seems it has 0.8 qts, large VAS.


I need a cheap but good woofer for my first OB project with NXT.

other woofers could be

monacor sp-382c or monacor sp-302c (both 30€)

visaton whc 30 8ohm (20€)

visaton whc 30 x (25€)

I'll cut woofer(s) with a behringer cx2310,about 500hz, maybe 700hz max.

questions:

-are coral woofers any good? or they are only cheap?

-it's better one 15" or two 12"? (I think 15") 

-so I can cut 1 woofer to 500hz, but I can also choose to use 2 woofers, 1 cut at 500hz and 1 to 200hz ca. what's better?


thanks a lot

[Rudolf]

Please stay away from the linked DYH 1220. It is bottom quality.
From the other listed woofers the Visaton WHC 30X would be my clear favourite. There is even a valid Boxsim data set for this driver. I know of people who had success with cutting off the dustcap to avoid chuffing noises at very high excursion.

In general I find two 12" drivers more powerful than one 15". But this depends on the exact drivers and the application you have in mind.

Rudolf

BTW: You must be joking about vintage CORAL drivers. They have always been good drivers and never have been cheap IMHO.

[tino84]

thanks a lot 

I'm thinking to make an H frame.

do you think will be better 2 woofer cutted in different ways, or 2 woofers wired together and cutted the same?

and also, would visaton works good also alone (only 1 woofer 12)?

[tino84]

Another question:

I think to starting with Monacor 382c, but I have to wait for

a) I've asked to Monacor the T&S, because on the web I've found different parameters
b) don't know still if the web-site where I found 382c will ship to my Country.

in a bad case, what would be another cheap but good 15"

(if not available,I will start with Visaton and wait to have a litlle bit of money to buy a good 15",like eminence)

[Rudolf]

would visaton works good also alone (only 1 woofer 12)?

I doubt that. Peerless SLS 12 seems to work as a single woofer - with much more Xmax than the Visaton.

Another question:
in a bad case, what would be another cheap but good 15"

http://www.traumboxen.de/ad-audio/r1524.htm is the cheapest 15" cast frame driver I can recommend for OB use. It is 58 € plus postage in Germany. You can contact them in English.

Rudolf

[tino84]

thank you for your explanations, I'll keep in mind 

[Poultrygeist]

Many old Japanese speakers contained decent FR woofers.

http://www.audiocircle.com/index.php?topic=102946.0

[tino84]

thanks to all.

I have had to change idea due to lack of money.

I finally choosed Monacor carpower sp-302c.(74€ for a pair shipped)

seems to sound good for now

[scorpion]

Hi Tino84,

I think your speaker choice is alright. But I don't think you have investigated your OB bass in full.
If you don't will EQ your bass in the low end you have to put it in an H- or perhaps U-baffle, but then you
will not be able to cross as high as 500 - 700 Hz without further measures. An H-baffle could be crossed perhaps up to 300 Hz without
further troubles.

If put on a flat baffle they can certainly go higher but then they will suffer a bit on the lowest range, so you probably would like to
EQ there. And this is perhaps your dilemma. If you don't already have the CX-2310 unit, do buy a mini-DSP instead and you are home.

/Erling

[tino84]

hi scorpion,

finally I decided to make an H frame, I used a panel 130x50cm for front, and two 115x50 for sides.

I have yet behringer, cutting woofer around 500hz.

Woffers seems pretty good, but I have to end them to run-in.

PS: I used those example (in italian) to build my frame

http://www.audiofanatic.it/Diffusori/tipolo/tipolo.html

http://www.audiofanatic.it/Articoli/Dipolo/Dipolo_Tipolo.html

[scorpion]

hi tino84,

Yes go ahead and build a baffle like the 'Tipolo'. A 'topless' H-baffle like that will save you from getting into trouble with quarter-wawe-resonances, like myself and MJK once proved.

Any regular H- and U-baffle will have those resonances and they have to be dealt with in one way or another. Read Martin J Kings clarifying paper on H- and U-baffles: http://www.quarter-wave.com/OBs/U_and_H_Frames.pdf

/Erling

[tino84]

thanks scorpion,

I'll read it tomorrow.

this is a pic of first realase (with only NXT mounted). I made an error and I made woofer hole too big, so I had have to make another panel, fitted back the "wrong hole panel" (otherwise I had to unmounting all), separated by a sound-absorbing sheet of 3cm (yes, I know it's a bit messing, but remember this is my first time  )

http://i43.servimg.com/u/f43/17/03/84/13/100_2510.jpg

[Rudolf]

this is a pic of first realase (with only NXT mounted).

This is reminding me of my first dipoles - angle irons and errors included. 
Could you tell us more about those NXTs? Each of them with its own exciter? I thought, those side wings would be exciting (sic) enough on their own. 

Rudolf

[tino84]

so I'm not the one to have made wrong holes?  what errors do you (and so I ) made?

for NXT, have a look here

http://www.audiocircle.com/index.php?topic=70541.0

an array of little panel driven by a single NXT usually it's not reccomanded, because of  bass frequencies (that a litlle panel would not reach).

Obviously, with a dedicated woofer and crossover, this is not a problem anymore.

I used little panel of balsa, blocked on nxt with a nail, and then covered every little panel with a sound-absorbing sheet (3cm depth )

I'm not understandig these

I thought, those side wings would be exciting (sic) enough on their own

do you mean, would be better if are clean from everything?

[scorpion]

I must say I am a bit surprised, tino84. I thought you wanted to add bass to your Vika Amon panel. So I was a bit curious about the dimensions you mentioned for the H-baffle.

Now I think you may have excitment all over the place. Not the least from the Monacor bass in the baffle and the wings. And all the random NXT exciters 'inside' the H. But to cite MJK from another thread: 'if it sounds good who cares'. Keep up the good work !
It certainly would have been interesting to listen to your speaker.

/Erling

[tino84]

And "it sounds very good, who cares" 

so, 2 details:

NXT are not directly mounted on the wings, but on  frame, that have to "capture" bad vibration from magnet.

Monacor is separated, mounted on a second panel, from sheet and from NXTs. So vibrations between woofer and exciter are reduced to the minimum (or so I think  ).

PS: I am a bit surprised too, I didn't think someone took a look on my Vika Amon NXT 
PPS:  I know iron angles are not the best way to mountin', but I'm so clumsy you better don't know  , I did not know other way to mount wings that little "wide" on the front.
PPPS: I'll search a way to cover/paint-with-something to give a better look
PPPPS: come hear and take a listen, what are you waitng for? 

thanks to all for interesting

[scorpion]

Hi tino84,

So we got fine explanations. I would be a bit cautious putting panels inside this kind of U because of risk for colouration of the sound.
I certainly would have thought of an open structure made from chicken wire or something similar.

/Erling

[tino84]

do you mean, so positioned NXT would colourate their sound?

if so, I was also thinking (yes, I've thinked various options  ) to something like a grill or stick, to clean wings and center panel.

second option, something on front panel , like a shelf, to hang NXT, only to the front.

in any case, chicken wire as you suggest is not so useful, I have to put NXT on something stable that cannot vibrate (to not produce "bad vibration")

[tino84]

just a little update, to say monacor sounds pretty good, good bass very "natural" in this OB

[Chano]

Thanks for the link to traumboxen.de : how do you rate A&D Audio R 1524 compared to e.g. Pyle Pro 15'' (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=292-218) ? and how would be the result of a subwoofer with two R1524 compared with one using two R 1830 ?