[nodiak]

Just a heads-up as they are on sale now. I ordered a pair to try as ob bass drivers. Using with original Hemp 8's (FR1), passive xo ~ 500 (guessing).
There are no frequency graphs for the Knight 15" (I asked), rats. Also I have no test equipment so for me this will just be seat of the pants sounds good or not.
This woofer is listed at 101db so will see if it works with 94db Hemp without resistors.
Here's their webpage:
http://www.shredmuzic.com/product_p/813-013.htm

Don

[ttan98]

Nodiak,

How is it like dealing with Shred music, any personal experience? I heard, their service is not crash hot. Thanks.

[nodiak]

Dunno yet, just ordered online Thursday afternoon. Got order confirmation right away, hopefully shipping notice on Monday. Metal heads on the weekend...still think they should be decent reference for bass drivers. We'll see.
Don

[ttan98]

Nodiak,

Good news for you, Magnetar(from DIYAudio) used 5 * 10" warrior with 16 ohm tap and parrallel them, about 5ohm, he said excellent performance in open baffle. Best of all very cheap.

[ttan98]

Nodiak,

mistake, 5 in parallel close to 3 ohms not 5 ohms.

[nodiak]

ttan98, yes have seen Magnetars threads (thanks bonjonno for the rec.), great experiments and diy'er. That's how I heard of Madison/Warrior/Knight drivers. Decided on 15" Knight instead of 2 x 16ohm Warrior 10" for a bit higher qts (1 vs. .87), lower fs (36 vs. 65), and maybe better spl match (101 vs 2 x 99). Easier to apply MJK 2 way idea too. Worth a try.
Also looking for room fitting dynamic sound on ob as some drivers sound too "ghostly" here, others too thick. These hemps don't fade out on ob as some do and aren't too incise either, looking for matching personality in bass. B200's have even more balls, (but 2 is enough for me nyuk nyuk).
Room has most to say about which driver for whose tastes, my room is suspended wooden floor and close sidewalls (12'). Ex. aggressive drivers become too much for me here (Augies, B200).
Then on to amp matching. All in fun toward spoiling the senses.   
Don

[ttan98]

Good for you, I can't buy them as I live in Australia, they don't ship that far.

Enjoy and report back.

cheers.

[JBspeakerman]

Hello....

Thanks for pointing out a potential 15.  Ran the traditional FS/VAS/QE math ratios and the true efficiency of this woofer... say below 500 hz or so.... caluculates out to only 88.5 DBW (.45%).  So the only way this thing could offer 101 + DBW would be up above 1K in a narrow peak.   See a lot of this.  But always good to see what is out there.  Sad to see true sensitivities being stated at more than 10 times actual values... no wonder there is no response graph offered.  This assumes the T/S values provided are accurate... and by looking at the basic design and so forth they seem viable.

JB

[nodiak]

Thanks JBspeakerman, realize 101 is peak of midband, was more looking for something with enough to mate to hemp 8 @ 300-500hz. What do those calculations show for Alpha 15 for comparison?
Don

[JBspeakerman]

Good afternoon from the Sierra Nevada foothills....

Using Eminence specs from their web site we have FS=41, VAS = 260L, QE =1.26, QM = 7.23 & RE = 5.88.  Xmax is 3.8 M  Peak.

Calculated for the Alpha 15 is 1.36% or 93.32 DBW.  Almost 4 times the operating efficiency in the bass region.  The two big differences are the VAS and Xmax.  The Alpha is about twice the VAS of the Knight and the Xmax is about half plus the Alpha has a slightly higher FS.

FWI...  Two Alphas in parallel will get you to where you need to go.   This would be about 99 dbw but as a 4 ohm load.   Double area... half the electrical resistance ...  or a 6 db gain in real world acoustic output per watt.   The parallel QE would be half... the VAS would double...... RE would be half.... FS, QM and xmax remain unchanged.   

Hope this info helps you with your evaluation.   Look for large VAS and small QE.  A pair of 12" drivers may be the ticket for your application if you are trying to keep things down in size.

Best

John

[nodiak]

Thanks John (from Pacific coastal shores of extra northern cal.).
Good info, I may have jumped the gun and should've posted a question first. I wouldn't want two 15's here, too small of a room. Possibly two 12's, but I'll need to think it over. I use a sub so may go back to idea of only needing ~ 80 hz cutoff for these mains, therefor even two 10's...will ponder.
However some vintage Philips 15's I'm now using below the hemps isn't doing too badly. Need 3-4 ohms on hemps with them, but it's liveable until I have a clearer idea.
Might call them in the morning to renig.
Sorry if I misled anyone.
Don

 

[Graham Maynard]

Hi Don,

The free 'XLBaffle' program is very useful for showing what drivers can do.  Available here;-
http://www.mhsoft.nl/SQL7/ViewDownloadFiles.asp

John raised an interesting point about quoted efficiency figures - they count for little at LF once a driver is mounted upon an open baffle.  I have two 'efficient' 12" Monacors still in their boxes for this very reason, and have just ordered 2x 15" to try on one channel mounted vertically.

You wrote;-
>> B200's have even more balls <<
and yet that is not obvious if you look at the manufacturers SPL plot and hear how 'thin' they sound in free air. 
On a baffle however they can surprise, if not go loud at LF before running into X.max limitations.

The other day I entered the B200 T/S parameters into XLBaffle and I was surprised at how much their LF could be lifted - the plot looked to match what is actually heard !


Cheers ........ Graham.

[nodiak]

Hi Graham, thanks for the link, I'll use it.
By now we're all used to the fact that published spl's are for the midband and won't represent the drivers abilities on ob in the bass region. But there are still what seems like inconsistancies from actual experiences.
The Alpha 15's have been satisfactorily used as bass boosters with B200's, like with Richards and others. But for some peoples tastes they have also shown to not match up with even the FE103e's when used in Martins 2 way, one person likes the 89db FE87e's without attenuation. So I think there is still some wiggle room in the numbers, and depending on xo point used, tastes/room/etc., all the usual suspects.
From others experiences I would expect a single Alpha 15 to not have enough to mate with the 8" hemps, so I passed them up. JB's equations show the Alpha having higher spl in the bass then the Knight. So I probably should've passed them up too. I went for them considering the possibility the 7 db difference in published spl's between them and hemps may have brought them close. Basically I just wanted to make a move and try something. If they don't match with the hemps I would try other lower spl fr drivers. To be honest I wish I didn't post about the drivers until after I tried them and found out what fr's they worked with, but I can also serve the community as a bad example ( ).
Your experiences with the B200's are good examples in showing there are sometimes surprises what the drivers can do vs. published specs and graphs.
I think with all our efforts at using drivers on ob we're in the midst of finding out any discrepancies of the real (live experiences) vs. ideal (specs, tech tools). I need to learn more of the ideal approach for sure. I've still found the last word on what satisfies is the room, assoc. equipment and tastes tho. This is a good lesson for me.
Don
 
   

[MJK]

By now we're all used to the fact that published spl's are for the midband and won't represent the drivers abilities on ob in the bass region. But there are still what seems like inconsistancies from actual experiences.
The Alpha 15's have been satisfactorily used as bass boosters with B200's, like with Richards and others. But for some peoples tastes they have also shown to not match up with even the FE103e's when used in Martins 2 way, one person likes the 89db FE87e's without attenuation. So I think there is still some wiggle room in the numbers, and depending on xo point used, tastes/room/etc., all the usual suspects.
From others experiences I would expect a single Alpha 15 to not have enough to mate with the 8" hemps, so I passed them up. JB's equations show the Alpha having higher spl in the bass then the Knight. So I probably should've passed them up too. I went for them considering the possibility the 7 db difference in published spl's between them and hemps may have brought them close. Basically I just wanted to make a move and try something. If they don't match with the hemps I would try other lower spl fr drivers. To be honest I wish I didn't post about the drivers until after I tried them and found out what fr's they worked with, but I can also serve the community as a bad example ( ).
Your experiences with the B200's are good examples in showing there are sometimes surprises what the drivers can do vs. published specs and graphs.
I think with all our efforts at using drivers on ob we're in the midst of finding out any discrepancies of the real (live experiences) vs. ideal (specs, tech tools). I need to learn more of the ideal approach for sure. I've still found the last word on what satisfies is the room, assoc. equipment and tastes tho. This is a good lesson for me.

Don,

I think that the ultimate lesson is that with less than an hour of effort you can simulate a whole host of driver and crossover combinations to see if they combine to give a good SPL response. I use this technique, along with many others, to scope out potential OB designs and don't spend a penny until I am convinced that there is a high probability of success. It works very well and the predictions are extremely accurate.

Martin

[JeffB]

ttan98,

I ordered two Warrior 15s from shredmuzic.com and did not have any problems.

[nodiak]

The drivers had already shipped, which was good service actually. So I'll see/hear how they work out soon.
JeffB, I'm assuming you didn't use the Warriors for ob/audio? Or open back cab? What do you think of their performance?
JB, it looks like the Warrior 15 specs fit better for ob bass driver. FS=36, Vas=234, Qts=.826, Qes=.888, Qms=11.83, Re=6.4. Xmax=6.35. Sens=100db.
Don

[JBspeakerman]

Good evening Don...

Yes the Warrior is a better bet than the Knight.... calculates out to 92.7 DBW or 1.17% and it has a desirable QT and Xmax....   Still not efficient enough for a passive solution in your situation ... but with a plate amp running some series induction it could do well.  The correct amount of series induction will add an order to the typical 2nd order roll off most plate amps come with ( becoming 3rd .... odd order) and make sonic integration with your hemp a lot easier... and add a bit of QTS to the sub to boot... so less correction required at the very low end of things to maintain a flat response.

What really counts in all of this is how you intend your set up to opporate... passive on the low end ... or with plate amp... what baffle width... wings or no.... desired low end cut off... required output levels and so on....  there of coarse is no single panacea.... it's all about engineering and priorities.  Here is a link to something I threw together over a couple of weekends for the 2008 Lone Star Audio Fest in Dallas last month.   Trying to demo what a good vintage Altec coax can do in an OB format with a little help from a 18" Eminence on the bottom and a first class crossover.   It (the 18) uses a plate amp... and some crossover tricks to get the low QTS 18"  (we are talking .22 QE and QTS) to get to play flat on the baffle in the pictures down to 32 hz.  Just rumaging around the parts bins and making the best of what I had on hand.  Again... it's all about engineering and choices.   Scroll down a ways and you will find me.   And a lot of other fun stuff in Dallas that weekend... no dogs... all great stuff!

http://www.dagogo.com/Events/2008LSAF.html

and

http://positive-feedback.com/Issue37/lonestar_08.htm

It is interesting to see what you can do.... there are few hard and fast rules.... but you do have to pay attention to the ultimate capabilities of the base equipment.....   and know what you can trade away to get where you need to be. 

I am working on a no holds barred ..... high output OB for the Rocky Mountain Audio Fest using a modern Altec 604 with helper woofer or woofers.   It will be similar in size and hopefully will work out well... you never know!!

All the above is to give you a perspective of what is possible... the options are endless... set your priorities and go for it!

Best

John

[ttan98]

ttan98,

I ordered two Warrior 15s from shredmuzic.com and did not have any problems.

Please report back what you think of them?

[nullspace]

I am working on a no holds barred ..... high output OB for the Rocky Mountain Audio Fest using a modern Altec 604 with helper woofer or woofers.   It will be similar in size and hopefully will work out well... you never know!!

Hi John --

Please do keep us aprised of your project for RMAF and what room you'll be in. I for one am already booked for the weekend and will be sure to stop by. I had previously seen pictures of your setup at LSAF, and wished I had gotten to hear it.

Regards,
John

[MJK]

Again... it's all about engineering and choices.

Exactly! The more engineering and the less guesswork can only increase the chances of a great sounding result no matter which style of speaker system you are building.