8" fullrange options for upper half of slot loaded open baffle...

coverto · « **Reply #20 on:** 14 Jan 2012, 06:55 pm »

Another vote for the Dayton Audio PS220-8 8". I've got a friend who's put them into OB's and loves 'em. I dig the Fostex FE206es in my Tonian speakers, though they do need some modification. As for Audio Nirvana, I have heard that the sweet spot of the line is in their higher-priced Alnico drivers, but have not really heard much about the cast frames and other entry-level models.

Chops · « **Reply #21 on:** 15 Jan 2012, 01:00 am »

Well Danny @ GR-Research wants me to give him a call on Monday. Apparently, he has an idea for my project that he wants to talk to me about. Hmm... I wonder what he has on his mind.

And I hate suspense!

Chops · « **Reply #22 on:** 15 Jan 2012, 05:38 pm »

Quote from: Poultrygeist on 14 Jan 2012, 12:50 pm

I have the Tang Band W8-1808/Alpha H-frames and WBL Betsy's/Alphas powered by SET/SS amps and while the Betsys are fun and enjoyable the TB's are in another league.

I really like the looks of the Daytons and hope to try a pair. They are certainly priced more reasonably than the TB's.

How do those Besty's sound in the treble region? Have you compared them to other drivers as well?

Poultrygeist · « **Reply #23 on:** 16 Jan 2012, 01:02 pm »

Although others differ on this, I personally like the Betsy's with a super tweeter which the Tang Bands don't need. The TB's sound smoother and more refined on the top and laid back while the Betsy's are slightly more aggressive.

The Betsy's upper end is an improvement over my Pioneer BoFu's which definitely require help in the higher frequencies. The motor on the Betsy's is small and cheap looking but for the money the sound is darn good. If I didn't own the Tang Bands I would have more praise for the Betsy's.

At some point I might cut off the whizzer/dust cap and replace them with a phase plug as the Betsy's can show some honk when played loud and they will play very loud. They have very good dynamics with good detail but lack the hyper detail of the smaller Fostex drivers.

The Betsy's sound very good running wide open while the Daytons may require some taming. The Dayton's with their more serious build quality probably have greater potential but at double the price they should.

JohnR · « **Reply #24 on:** 16 Jan 2012, 01:04 pm »

Quote from: Chops on 13 Jan 2012, 12:35 am

I am in the process of gathering information, ideas and parts for Nelson Pass' slot loaded open baffle. I've already ordered a lot of twelve 8" Peerless India 12 ohm drivers. Now I'm looking for fullrange drivers for the top end.

Why don't you use what Nelson uses on top? (sorry if this was suggested already, I didn't notice it)

opnly bafld · « **Reply #25 on:** 16 Jan 2012, 01:10 pm »

Quote from: JohnR on 16 Jan 2012, 01:04 pm

Why don't you use what Nelson uses on top? (sorry if this was suggested already, I didn't notice it)

Lowther PM6A $1295/pr

JohnR · « **Reply #26 on:** 16 Jan 2012, 01:15 pm »

Oh I see. Well, in theory I have a pair of FA22s on the way, but I can't help thinking that with this kind of driver, it's just going to have to be "try it and see for yourself". No?

Chops · « **Reply #27 on:** 16 Jan 2012, 01:34 pm »

Thanks for the mini-review Poultrygeist. Much appreciated.

JohnR, from what I have read, I don't think I'd be a fan of the Lowther drivers anyway. There always seems to be a love/hate relationship with those drivers, typically with the hate part being a little more than the other.

JohnR · « **Reply #28 on:** 16 Jan 2012, 01:37 pm »

Can I ask? Have you owned any fullrange-driver speakers?

Chops · « **Reply #29 on:** 16 Jan 2012, 01:43 pm »

Quote from: JohnR on 16 Jan 2012, 01:37 pm

Can I ask? Have you owned any fullrange-driver speakers?

Yes sir. I still have bone stock Fostex FE103E's that have several thousand hours on them that I still use. And I had a pair of fully tweaked FE127En drivers from Dave (Planet10), but sold unfortunately.

With this project, I want to step up the size of the fullrange drivers, not to mention this time around the entire speaker will be an OB design.

JohnR · « **Reply #30 on:** 16 Jan 2012, 02:44 pm »

Is there a specific reason for going with a larger FR driver?

Poultrygeist · « **Reply #31 on:** 16 Jan 2012, 04:01 pm »

This may not be germane to 8 inchers for the slot loaded OB discussion but I'm anxious to try an even larger driver in OB's atop H-frames. The 12 inch Eminence Beta 12LTA is inexpensive and with a super tweet might be lots of fun.

The nice thing about H-frames is you can try lots of drivers on top with minimal effort.

Chops · « **Reply #32 on:** 16 Jan 2012, 07:02 pm »

Quote from: JohnR on 16 Jan 2012, 02:44 pm

Is there a specific reason for going with a larger FR driver?

Because I want to be able to cross over as low as possible to get the most out of the fullrange drivers, and no crossover anomalies within the critical listening range. I'm shooting for roughly 150Hz crossover point.

Badwater · « **Reply #33 on:** 16 Jan 2012, 11:15 pm »

I am using a vintage EV SP12B with a Fostex T90A supertweeter over top a Alhpa 15A H frame. This is a mighty fine system.

Poultrygeist · « **Reply #34 on:** 16 Jan 2012, 11:41 pm »

I hear you Badwater. It's hard to do wrong on top of H-frame Alphas.

JohnR · « **Reply #35 on:** 17 Jan 2012, 08:57 am »

Quote from: Chops on 16 Jan 2012, 07:02 pm

Because I want to be able to cross over as low as possible to get the most out of the fullrange drivers, and no crossover anomalies within the critical listening range. I'm shooting for roughly 150Hz crossover point.

That is not a function of driver size though. Most FR drivers 3" or larger will have no problems with a 150 Hz crossover. The low-frequency rollof is dominated by the baffle size, not the driver size. The driver size will have much more of an effect on sensitivity and peak output level (and to a lesser extent, power handling), at the cost of on- and off-axis FR smoothness. (Speaking in generalities.)

I got the impression that you are concerned about high-frequency response, which is why I asked. Unless sensitivity and output level is a concern, I wonder if you should look at the current Mark Audio drivers.

Chops · « **Reply #36 on:** 17 Jan 2012, 01:42 pm »

Quote from: JohnR on 17 Jan 2012, 08:57 am

That is not a function of driver size though. Most FR drivers 3" or larger will have no problems with a 150 Hz crossover. The low-frequency rollof is dominated by the baffle size, not the driver size. The driver size will have much more of an effect on sensitivity and peak output level (and to a lesser extent, power handling), at the cost of on- and off-axis FR smoothness. (Speaking in generalities.)

I got the impression that you are concerned about high-frequency response, which is why I asked. Unless sensitivity and output level is a concern, I wonder if you should look at the current Mark Audio drivers.

Well I do really want good top end performance. I don't want to resort to helper tweeters or EQ. Off-axis performance would be preferred as well. However, I also want good transient response, so efficiency is a major plus. But on that note, I'm in an apartment, so playing loud isn't an option.

Also, I figured going with a larger driver would help add some "heft" to the lower midrange, especially with male vocals. I want it to sound natural, not thin. Again, I guess this goes back to the baffle size. But that's the other thing, I can't have a huge baffle either in our small-ish apartment.

JohnR · « **Reply #37 on:** 18 Jan 2012, 03:14 am »

What size baffle are you thinking of? You may want to try a couple of sims, as if the baffle is too small you will need to either move the crossover point up or "resort to EQ"

Chops · « **Reply #38 on:** 18 Jan 2012, 03:16 am »

Quote from: JohnR on 17 Jan 2012, 08:57 am

I got the impression that you are concerned about high-frequency response, which is why I asked. Unless sensitivity and output level is a concern, I wonder if you should look at the current Mark Audio drivers.

I'm looking, and am wondering on the Alpair-10 drivers. Any experience with these?

They look like a solid little driver.

Chops · « **Reply #39 on:** 18 Jan 2012, 03:20 am »

Quote from: JohnR on 18 Jan 2012, 03:14 am

What size baffle are you thinking of? You may want to try a couple of sims, as if the baffle is too small you will need to either move the crossover point up or "resort to EQ"

For the bass section, I was thinking somewhere in the lines of 20" wide total and 8" deep on either side. As for the fullrange baffle, I don't know yet.

I'm thinking if I make the areas inside the slot as tight as possible to the drivers, that will drive the resonant frequency of the slot up much higher than I will be crossing them over. I'll have to look for it again, but I think Nelson Pass or someone said the resonant frequency of his slot was somewhere in the 400Hz range.