Goldwoods for OB?

dgator · « **on:** 29 Nov 2010, 10:44 pm »

With the Goldwoods on sale, I'm thinking it's time to try an OB system. I'd like to use two 15" drivers per side. The Eminence 15a appears to be the standard but at these prices I'd like to try the Goldwoods. Both are the requisite high Q drivers. Anyone have an idea which of these would be better in this application?

edit: http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=290-394&scqty=4

http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=290-346&scqty=4

mcgsxr · « **Reply #1 on:** 29 Nov 2010, 10:50 pm »

Having chased many different OB woofers in the past, I am sure I know the GW ones you are thinking of. http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-384 - these?

Folks have tried the 15's and 18's, and some find them pleasing.

Others have reported that the Alpha 15 is just flat out the best, cheapest option.

I have not heard either of them, but bought unheard the 12's I am using - and still using 4 years later.

panomaniac · « **Reply #2 on:** 30 Nov 2010, 02:01 am »

The Goldwood 18" are very nice for OB. Especially 2 per side.

Blooze · « **Reply #3 on:** 30 Nov 2010, 04:55 am »

Quote from: panomaniac on 30 Nov 2010, 02:01 am

The Goldwood 18" are very nice for OB. Especially 2 per side.

Definitely. The ones John Busch brought to LSAF last year sounded pretty dang good. I think those were the $80 18" too. Those speakers are what is having me want to try a set of OB's.

Russell Dawkins · « **Reply #4 on:** 30 Nov 2010, 06:29 am »

Quote from: Blooze on 30 Nov 2010, 04:55 am

Definitely. The ones John Busch brought to LSAF last year sounded pretty dang good. I think those were the $80 18" too. Those speakers are what is having me want to try a set of OB's.

Could you describe the speakers John Busch brought in terms of drivers, please? Were they 2 - 18s a side? What was the configuration and driver type for the rest? Do you have a link to more info?

Thanks

edit - I think I found the info - at the bottom of this page:
http://www.hifizine.com/2010/06/lone-star-audio-fest/

Blooze · « **Reply #5 on:** 30 Nov 2010, 01:10 pm »

Quote from: Russell Dawkins on 30 Nov 2010, 06:29 am

Could you describe the speakers John Busch brought in terms of drivers, please? Were they 2 - 18s a side? What was the configuration and driver type for the rest? Do you have a link to more info?

Thanks

edit - I think I found the info - at the bottom of this page:
http://www.hifizine.com/2010/06/lone-star-audio-fest/

Yep. Those are the ones. Stunning low, quick bass. Very balanced considering the room he was in. John always brings excellent sounding speakers to the show.

JBspeakerman · « **Reply #6 on:** 30 Nov 2010, 03:19 pm »

The Goldwood 18" (1858) is a bit of a mystery. And that's after using it in a couple of projects.

BTW, Blooze, thanks for your positive assessment of my humble offerings at LSAF!

PE specs on Xmax are at odds with what Goldwood claims on their spec sheet. I think the PE value is closer to reality.

I have a spec sheet and response curve from Goldwood for the 1858. Have to figure out how to attach them, share them here. Hey Pano, how do I do that?

The 1858 does require some work to control the cone break up up in the 2K area. A pair on a 24" wide baffle with 10" wings can play flat into the upper 20" with marginal crossover work. Their frames however are VERY light and easily bent. Playing with a single driver version of what I played last year at LSAF. More on that as, or, if, the project gets anywhere.

For OB work, the 1858, when on sale, is a bargain. However, with the high QTS (mine measured 0.92 with the WT3) and huge VAS the 1858 is not suitable for any traditional enclusure.

Blooze · « **Reply #7 on:** 30 Nov 2010, 03:39 pm »

Quote from: JBspeakerman on 30 Nov 2010, 03:19 pm

The Goldwood 18" (1858) is a bit of a mystery. And that's after using it in a couple of projects.

BTW, Blooze, thanks for your positive assessment of my humble offerings at LSAF!

PE specs on Xmax are at odds with what Goldwood claims on their spec sheet. I think the PE value is closer to reality.

I have a spec sheet and response curve from Goldwood for the 1858. Have to figure out how to attach them, share them here. Hey Pano, how do I do that?

The 1858 does require some work to control the cone break up up in the 2K area. A pair on a 24" wide baffle with 10" wings can play flat into the upper 20" with marginal crossover work. Their frames however are VERY light and easily bent. Playing with a single driver version of what I played last year at LSAF. More on that as, or, if, the project gets anywhere.

For OB work, the 1858, when on sale, is a bargain. However, with the high QTS (mine measured 0.92 with the WT3) and huge VAS the 1858 is not suitable for any traditional enclusure.

Sorry I haven't got back to you on a design yet, John. I was thinking a single 18" similar to your 2 18" design, augmented with a couple of seperate sub enclosures. Hope your move went well.

.....Shane

panomaniac · « **Reply #8 on:** 1 Dec 2010, 02:54 am »

Quote from: JBspeakerman on 30 Nov 2010, 03:19 pm

I have a spec sheet and response curve from Goldwood for the 1858. Have to figure out how to attach them, share them here. Hey Pano, how do I do that?

I think that on this forum you have to create a gallery and upload the there. Or email them to me, I'll do it.

JohnR · « **Reply #9 on:** 1 Dec 2010, 02:58 am »

Just click on the picture button when posting - it looks like this:

opnly bafld · « **Reply #10 on:** 1 Dec 2010, 04:01 am »

Quote from: Blooze on 30 Nov 2010, 01:10 pm

John always brings excellent sounding speakers to the show.

....and he keeps folks down the hall at RMAF up too late.

Lin

panomaniac · « **Reply #11 on:** 1 Dec 2010, 02:54 pm »

Darn! Where have they been hiding that picture button?

Here are the documents.

panomaniac · « **Reply #12 on:** 1 Dec 2010, 03:31 pm »

And here is an impedance sweep done by JB.

Not crazy about the images on this forum software. The above was a very clear png file at 18K. Now it's a dirty jpeg at 29K. Not really going in the right direction.....

Russell Dawkins · « **Reply #13 on:** 1 Dec 2010, 04:20 pm »

Just out of curiosity - is it just a coincidence that Goldwood's stated Fs and JB's measured Fs are both precisely 30.28Hz?

JBspeakerman · « **Reply #14 on:** 1 Dec 2010, 04:33 pm »

Hey Russell

So you noticed! It is, or should I say, was what it was! You can see from the impedance curve that WT3 generated that the 30.28 is not a made up value. I didn't notice at the time. What was interesting to me, the consistency of the 4 units I purchased. All were VERY close to the WT3 post.

JBspeakerman · « **Reply #15 on:** 1 Dec 2010, 04:40 pm »

As for my alleged RMAF sleep deprivation program, it was 10:30 AM at hotel wide audio show! Geez!! Well, I did do that live play back sort of thing two mornings in a row! Seems the neighboring room was occupied by a not to be named wife of a high end audio magazine editor. Guess she had been up late two nights in a row?

JBspeakerman · « **Reply #16 on:** 1 Dec 2010, 05:32 pm »

Getting back to the original 15" OB topic, in terms of bang for the buck in a PE sourced 15" OB woofer candidate, I would check this offering out.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=292-415

panomaniac · « **Reply #17 on:** 1 Dec 2010, 08:34 pm »

Qes = 1.92? Does that 15 even have a magnet?

JBspeakerman · « **Reply #18 on:** 1 Dec 2010, 08:55 pm »

For $23 you want a magnet too!!

panomaniac · « **Reply #19 on:** 2 Dec 2010, 05:06 am »

Short the voice coil and you'd have a mildly damped passive radiator!