[rick57]

Hi

The Mach 5 IXL 18" is great value in terms of VD per $/ Euro etc for open baffle bass, where the ample Vd will be great:

http://www.soundsolutionsaudio.com/zencart/index.php?main_page=product_info&cPath=2_18&products_id=12

Xmax isn’t stared there, but its 22.0 mm. 

I’m in Australia: if I were in the States I might get Augies.

But are there any distortion tests available on them. Anyone built them, what do you think of their sound quality?
What can be said about their quality from the design?

Similar quality to the big Eminence drivers? However the most Xmax in an Eminence, is the Kilomax Pro-18 with only 9.8 mm.

Thanks

[Russell Dawkins]

I'd be more inclined to get 4 of these:
 http://tinyurl.com/5uyo5c
pocket the $65 savings per side (you were talking stereo, weren't you?) and enjoy the fact that my amp now behaved as if it were 10 times more powerful! 

[ttan98]

I'd be more inclined to get 4 of these:
 http://tinyurl.com/5uyo5c
pocket the $65 savings per side (you were talking stereo, weren't you?) and enjoy the fact that my amp now behaved as if it were 10 times more powerful! 

This woofer is similar to the one MK uses in his 2-way the 18" woofer in a single H-frame, no equalization is required, gives awesome bass sound, excellent value if you can stand the sight of 2 gigantic H-frames in the music room. That is the limiting factor for me. 15in woofer is already too large.

[Magnetar]

I bought some of the Goldwood 18's from Parts Express a few months ago and sent them back. They have very high distortion in the bass and midbass plus a nasty early breakup that is audible even with a 80 hz fourth order low pass

The Madison Warrior woofers have all been good for me with OB. The Warrior 15 that goes for around 35 dollars on ebay is a great OB woofer! I think the huge spider is the reason. The Xmax is real, and they are pretty darn efficient even on a narrow 26" baffle.. IMO they are far better than the Goldwood or Alpha 15 Eminence (another high distortion driver that sounds bad) - I also should say I have used the Madisons for years and never had one burn or rub even at very realistic concert levels. They just keep going and sound great

My main panels in my OB line array use the Warrior 10's - they work well 70 to 1.2K  - I use them up to 800 with a first order passive line level xover and they don't need a notch filter to get rid of the breakup at 2.4k it's pretty mild

[Magnetar]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200270421234&ru=http%3A%2F%2Fshop.ebay.com%3A80%2F%3F_from%3DR40%26_trksid%3Dm38%26_nkw%3D200270421234%2509%26_fvi%3D1

Madison 15

[-Richard-]

Hi Magnetar ~

One Eminence Alpha 15A hooked up to one Visaton B200 driver in parallel for each flat panel stereo baffle in my system sounds quite lovely... flawless music reproduction. With the right amplification it easily goes down to the 30Hz region... and is clean and articulate. Perfect? Gee... I wouldn't know that. I once owned the Silver Iris Augies but I never had a chance to compare them with my current Alpha 15A's.

I thought perhaps others might want to know that... you know... have a "second opinion" as they say in medicine.

Warmest Regards ~ Richard

[rick57]

If the Goldwood are 18 inches and only $49, with no specs there’s likely a catch. Magnetar found it (but was able to get a refund I hope). If they're for MIs, it probably wouldn’t have much Xmax.

Magnetar
Thanks, but the Warrior 15s only have an Xmax of 0.25", 6.3 mm. I’m after something to use down to about 30 Hz. The Mach 5 IXL 18"s have an Xmax of 22 mm 0.9 inch.

The Eminence Alpha 15A has high Q and low price on its side, and are reasonable quality, but Xmax is only 3.8 mm, so you need > 10  Alpha 15As to equal one Mach 5 IXL 18 . .

In Vd, two Eminence Kilomax Pro-18 equals about one Mach 5, but they are about the same price.

Any knowledge of the Mach 5’s?

[ttan98]

If the Goldwood are 18 inches and only $49, with no specs there’s likely a catch. Magnetar found it (but was able to get a refund I hope). If they're for MIs, it probably wouldn’t have much Xmax.

Magnetar
Thanks, but the Warrior 15s only have an Xmax of 0.25", 6.3 mm. I’m after something to use down to about 30 Hz. The Mach 5 IXL 18"s have an Xmax of 22 mm 0.9 inch.

The Eminence Alpha 15A has high Q and low price on its side, and are reasonable quality, but Xmax is only 3.8 mm, so you need > 10  Alpha 15As to equal one Mach 5 IXL 18 . .

In Vd, two Eminence Kilomax Pro-18 equals about one Mach 5, but they are about the same price.

Any knowledge of the Mach 5’s?

I tend to agree with MK Xmax is not so crucial, 3.8mm from Alpha 15 is suffice and 6.3mm from Warrior is even better.

[MJK]

I have used the Alpha 15A and the Goldwood 18 and have not experienced any of the problems described by Magnetar. I believe both of these drivers are a great value and can be paired with much more expensive drivers without giving away anything. My design method is to always cross the larger woofers below 200 Hz which should be well below any break-up modes. I am not convinced that spending more money on an OB woofer will buy better performance in my music only system (I don't know much about HT demands).

[mcgsxr]

I use 12's from Mach 5, but have never used the 18's.

Great build quality, and Mark was excellent to deal with.

If you have the dough, go with the Mach 5 18's in my estimation.

Good luck!

[Magnetar]

To clarify the 18's I had they were the Goldwood GW-1858 - In my experiments so far when you get above .9 or so QTS drivers start to sound 'wooly' or vaque (too much harmonics) - I think it's because I've become used to bass from a good bass horn that is the opposite sounding often being too shallow or too precise (low in harmonics) - The Alpha 15 sounds like that to me too - Parts Express took the Goldwood back no problem. I can see how people may like the sound of either of these because on a board they still sound better then most high buck drivers in a typical  box. I tend to go with a driver with a little quicker roll off (lower QTS) and try and stay away from drivers that need notch filters in the upper range

Of course YMWV and it depends on the goals of the listener and his individual application to seek his/her outcome.

Surely the amp driving the woofer will have an effect where I tend to use beefy high power, low output impedance, low negative feedback bipolar SS amps to drive my bass. I also high pass the bass a bit above resonance and find the bottom octave (ot two) is better handled by a horn loaded driver.

[rick57]

I also like tight bass, so while the Eminence Alpha 15A’s very high Q is good for open baffle, tend to feel safer with the Warrior

And if the Warrior has more Xmax, maybe offsetting the more "modest" Q . . 

Cheers

[JBspeakerman]

Hello all...

Straight up... like all "best of"... there is of coarse rarely one answer.   The answer will be driven by the application and other realities... such as... but not necessarily limited to cost considerations... overall system performance goals... major design considerations (Powered sub ... passive crossover... active crossover) and .... well I could go on for a lot longer than most would find interesting.

You have to set some parameters and the more you set... the closer you will be to a realizable.... sensible answer.  Any of the the so far mentioned drivers could be on a "best of" list... given consideration of the above.  Sorry to be such a stick in the mud... it is a fun discussion.. but it needs a focus.

My $0.02 worth.

JB

[rick57]

Hi JB

You're right. I asserted that the Mach 5 IXL 18" is great value in terms of VD per $. It may have more Vd then a situtation (listening size, music, dB etc) needs.

Btw, off topic, but what approx f3 do you think you get from your 18 inch P.Audios, and do you use EQ?

Cheers

[gainphile2]

There is a good collection of dipole woofer distortion test here:

http://www.mfk-projects.com/woofers.htm


I also recently did a nonlinear distortion measurement of Eminence Alpha 15A:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=132665

[Magnetar]

It's always a great idea to use an OB woofer with a high pass low level crossover above resonance. That is if you want accurate high definition bass (like me)- The woofers that work best really need this due to their weaker motors and high Q. The graphs you pointed at with the weak motor Alpha 15 show this harmonic distortion and it is clearly audible when you can compare to a proper designed low distortion system.

There is a good collection of dipole woofer distortion test here:

http://www.mfk-projects.com/woofers.htm


I also recently did a nonlinear distortion measurement of Eminence Alpha 15A:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=132665

[JBspeakerman]

Hello Rick 57....

The 18" coax on a 26" wide baffle with about 1100 sq in of area and modest 7" or so wings is showing an f3 in the mid to upper 30's in most environments.  Yes you do get some cabin effects with a dipole of this size.  Have a peak in the mid 50's caused by the large amount of inductance I am using to flatten and tailor the responce... all passive at this point.   Also have a healthy shunt cap too.   Working the inductor - shunt cap values to smooth out the mid 50's hump and still maintain the needed upper roll off to match the low end of the compression driver.   I could extend the f3 down a bit further... but there is not enough clean displacement to justify going any deeper.   As usual... it's a engineering balancing act.  The bass the woofer does produce is very clean with huge dynamics.   Maintains pitch pretty well and can play very loud.  The pitch quality will improve further once I tame the 50's hump.

JB

[dyohn]

I'll make a pitch for the Exodus Audio DPL15 driver.

http://www.diycable.com/main/product_info.php?products_id=684&Cid=54f4658165471aac757130d7e5b2dc04

[panomaniac]

I've not heard the Exodus DPL-15 but I've seen it.  Quite impressive!  Seems like a lot of driver for the money.
You'd need some big power behind it, I think.

[rick57]

In the end I decided to go "all out" for quality, and get the GR servo setup
http://www.gr-research.com/index.asp?PageAction=VIEWPROD&ProdID=142

In a few months I  hope to get to set them up, with the 15" P.Audio coaxes above them.

JB,

That's great that the 18" can get an f3 in the mid to upper 30's, I thought with that modest Qts it mighn't be that low:
Danny at GR is experimanting with P.Audio coaxes - the BM12-CXA, but believes that the CX38 series
"the response is way too rough and the Qts is way to low for it to be used in an open baffle. I'd never get the woofer to play down low enough to reach the servo subs and it wouldn't work."
http://www.audiocircle.com/index.php?topic=61023.0
at odds with you getting an f3 in the mid to upper 30's (?)

cheers

rick