2 way speakers - 6.5" or 10" driver?

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Here is a quick question for everyone, is it possible to make a good quality 2 way speaker using a 10” driver instead of the ‘classic’ choice of a 6” / 6.5” driver with tweeter. Lots of people on the internet say it’s very difficult because a 10” driver gives poor sound dispersion and hence is very difficult to get a clear and wide stereo-image, compared to a 6.5” driver. Yet lots of 10” drivers have some impressive specs…….(lets forget problems such as the extra enclosure size that is necessary!!)

Anyone any opinions about using a 10” driver as apposed to the classic choice of 6.5”, has anyone had any success using a 10” driver in a two way design?
 
I have made some 2-way speakers with very large woofers before. Dispersion is definitely something you need to consider, but depending on how you like your speakers to sound, it need not be a problem.

With narrower dispersion, you will hear more direct sound and less reflected sound. This tends to make the large woofers sound darker and less airy than smaller ones. This may be considered bad, but on the other hand it reduces the room's influence on the sound.

Nevertheless you still need to choose a lower than normal crossover point, which makes it hard to find a tweeter that will cover a wide enough bandwidth.
 
The problem is not the narrow dispersion per se; the problem is what happens in the crossover region as you transition from a driver with narrowing dispersion to the tweeter, which will (by virtue of its geometry) have wider dispersion. Get the on-axis response right and the reverberant energy will be wrong.
 
jr, I think that's wise. It's a common commercial format and it's gotten to be so for a reason.

5th, the problem is geometry- no conventional 10" driver will have good off-axis response at frequencies where it's practical to cross over to a normal tweeter. Now, if you can use a tweeter that works well at 1kHz, you've got options. But the vast majority don't; 3K is about as low as you'd want to take most 1" domes.
 
How would an OB configuration affect the problems with the larger woofer? I'm using 8" woofer in my small baffles and I dont' think I'm having any of these issues, but then again, it is still a pretty small driver (and I am considering finding some larger ones to try grabbing an extra .5 to 1 octave response at the bottom (I'm down 3db about 45hz and probably more like 12 at 35hz).

Also, for mating a tweeter, why not go planar, like a BG Neo 3 or 8 or a scavenged Monsoon satellite? They all have fairly narrow dispersion (except the PDR versions of the BG Neos, though that's mainly in the high freqs with dispersion widening as the frequency rises) and will go relatively low (the BG Neos are listed at PE down to 2khz, but BG's spec sheets show designs using them down into the 500-700hz range; Monsoon satellites from the last generation made go down into the low 200s before rolling off, which they do steeply, only presenting anything audible down to 180hz before just not responding at all in my testing, though I have fed them a fairly high level 20hz signal directly without damaging them in the slightest, so they could be run full with just a coil on your large woofer).

Just some thoughts . . .

Kensai
 
SY said:
jr, I think that's wise. It's a common commercial format and it's gotten to be so for a reason.

5th, the problem is geometry- no conventional 10" driver will have good off-axis response at frequencies where it's practical to cross over to a normal tweeter. Now, if you can use a tweeter that works well at 1kHz, you've got options. But the vast majority don't; 3K is about as low as you'd want to take most 1" domes.

Yeah thats what i was saying.
 
I do agree with the rest of the group that 10" woofer in a 2 way for home use is sub optimal. But, If you are still interested with that design you should look at Genelec, Adams, and event studio monitors. These devices are designed for near field use in a narrowly defined sweet spot. If you can accept those two conditions, you can get good results. They pretty much all use 24db active LR crossovers, and you can look at the crossover points they use on their websites. As far as dome tweeters go, seas millenium, SS 9500, Morel Mdt33 and supreme 110s all can be crossed low. (1400-2000 hz, with 24db LR). You might want to do additional searches on tweeters in low frequency crossovers.
 
Do the same problems that 10" driver have apply equally to 8" drivers in general or to a lesser extent? In other words, are 8" drivers a viable option in a 2 way DIY speaker design?

P.S Thanks to everyone who replied to my original post...I think this page could have saved a few people considering DIY speaker options a lot of money, and trial and error - myself included!
 
jrhilton said:
Do the same problems that 10" driver have apply equally to 8" drivers in general or to a lesser extent? In other words, are 8" drivers a viable option in a 2 way DIY speaker design?

P.S Thanks to everyone who replied to my original post...I think this page could have saved a few people considering DIY speaker options a lot of money, and trial and error - myself included!
You could do it (Linkwitz' Orion does the same) but it's still recommended to cross over low. Linkwitz's Orion is crossed over at 1.44kHz (4th-order network, IIRC).

EDIT: Then again, the off-axis dispersion for the 8" in the Orion is higher because of its dipole behaviour. Monopole drivers will start to beam faster than dipole drivers.
 
I think 8s are a definite possibility for successful 2 ways, I was going to buid the following but in my livingroom the speakers would have ended up close to the TV, too close for my liking I have screwed one CRT up already by putting big drivers too close.

Volt BM220.8 (bass midrange)


Morel MDT-33se (soft dome tweet)
http://www.morelusa.com/tweeters/mdt-33se/mdt-33se.html
or
Hi-Vi RT2H-A (ribbon tweet)
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=297-407

My thoughts with the Morel was to use 18dB slopes crossing over about 2.2kHz which looked pretty good from a phase point of view, I never modeled it with the Ribbon.

I bought the Volts but nere got round to getting tweets, I tried one in a 30l box with a cheap morel tweet and was suitably impressed with them, the sweet spot was reasonably sized, they loved a good dollop of power and certainly outclassed Genelec 1032As I have at work in my opinion, very clean and natural sounding.

I would certainly look at them as a possibility, I may be persuaded to sell the Volts as they are not being used at the moment and I can't afford suitable tweets to go with them.
 
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