Most recommended Coax for OB?

[Jeroenkv]

Hello,
I like to try a coaxial speaker in my next OB project. Preferable I like to use one driver. So a 15"with high Xmax has preferences (or 18"?). Which coax can you recommend?

Current 15"options I see are:
Hawthorne Silver Iris (Xmax 3.45mm, 70cm baffle max 95 db at 50hz)
18 Sound 15CX1000 (Xmax 6mm, 70cm baffle max 100 db at 50hz)
BMS 15C682 (Xmax 5.5mm, 70cm baffle max 99 db at 50hz)

Smaller option:
18 Sound 12CX800 (Xmax 6.25mm, 70cm baffle max 96 db at 50hz)

Are there better options?

Regards

[JoshuaTechnomage]

You might want to add the Radian 5215B to your list, but I've heard good things about all the coax's you mentioned. Not too many people play around with the modern pro driver coax's, particularly in home hifi so it's hard to find anyone that's listened to them, much less compared several.

[Jeroenkv]

Hi Joshua,
It is difficult to determine what the quality is of these pro-drivers compaired to high-end home audio drivers. I have possitive experience with a Ciare 15NdW, but that's all!!

Do you now if these compression drivers are any good compaired to the usual tweeters?

The Radian looks nice, only the Xmax is smaller (2.85) than the others.

Regards,
Jeroen

[JoshuaTechnomage]

Also look at this thread:

http://www.diyaudio.com/forums/showthread/t-23051.html

I have not had personal experience with compression drivers vs. conventional hifi drivers. They are generally considered a little less smooth but far more dynamic. It varies so much though depending on application. The Radians seem to be the best option from what I've read but I'm sure that depends on many factors. I would love to try one of these with a steep digital crossover and digital equalization.

I'm not worried about xmax so much, these are all designed to play much louder than they would need to be played in a living room. Unless you plan to boost the bass I don't think it's a big issue. You might not get enough bass in an OB with these alone, you would probably need a separate sub or combine with something like an Eminence Alpha 15A mounted below it in an OB. The Alpha's have a high QTS so they don't need to be equalized for bass.

What are your goals with this project? For what kind of music?

I have also been thinking about another project maybe using the B&C DCM50 compression driver from around 350hz - 10khz, a Fostex T500MKII tweeter and 4x Eminence Alpha 15A in OB. That way the total sensitivity should be around 109db/watt. But I wouldn't have the money for that for a long while.

[JoshuaTechnomage]

Some links to compression driver projects:

http://nullspace.us/tt12.html

also here:

http://www.diyaudio.com/forums/showt...postid=1706939

http://www.diyaudio.com/forums/showt...postid=1093056

http://vincent.brient.free.fr/round_horns.htm

A long thread about some compression drivers:

http://www.diyaudio.com/forums/showthread/t-92135.html

[Jeroenkv]

Allot of info I'm going to read. Thanks!

At this moment I have a OB design with a B&G Neo8PDR and 2 x Aurasound NS12, Groundsound DSP and 3 times Hypex UcD180HR class D. It is a 2.5 design with crossover at 600hz and the second woofer at 150hz. Optimal tuned to in-room acoustics.

Currently I have no idea how to improve this, but I'm always looking! An OB point source would maybe do the trick...... hence the Coax question.

Another option good be a AE TD12H (Xmax 14mm, 102db at 50hz) and a B&G Neo3 tweeter crossover at 1200hz. But this a totally different way again.

[serph1nia]

I believe that a singe driver speaker just can;t be done properly without spending unjustified amounts of money. It might be better to use a high sensitivity woofer up up too the 150hz, maybe 300hz and then use a smaller 'full range driver'.
full range driver are pretty much always a compromise, either bass or treble. With the two way system you have the good quality treble al the way down to the 150-300hz and then the woofer takes over. not only will the quality of the bass be better. You can;t really point out where bass is coming from at that frequency.

Another way is to use a iris full ranger and add a tweeter at 7khz+ to it.

Of course, a passive crossover and a single amplifier will be possible.

[Jeroenkv]

I understand your point, but a Coax driver is a 2 way driver. It is a woofer with a seperate tweeter in the middle. My question is if this tweeter performs as wel as in a normal setup? Or is the quality of this kind of pro tweeters lower?

[Brett]

Originally posted by Jeroenkv
Or is the quality of this kind of pro tweeters lower?

It can and typically is higher SQ than domes.