Dayton Reference 12HF, 15HF users? Building new bass system to match hornloaded tops.

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Hello!

I am gathering information for a project that I will soon be starting. I am currently using fairly large bass horns (22.5 cu. ft.)with 15" drivers to cover the lower range up to 175 hz or so where the 3-way horn loaded tops and single ended triode amps do their thing. I am retiring the bass horns because of integration issues and am looking for more linear response from 175 hz. down to lower cutoff. Amplification is provided by a Crown K2, signal processing by DBX Driverack 260.
I am strongly considering going with sealed enclosures and multiple drivers in a push-pull arangement. EQ is available if necessary and ample power is available. I will be building two cabinets, and I'm considering either two Dayton Reference 15HF drivers per cabinet, or four Dayton Reference 12HF drivers per cabinet. Twelve cubic foot internal is what I'm aiming for. Maximum SPL for the upper horn section is around 110 db. I'm interested in impressions from users of the Reference subwoofers, and also non users with suggestions for other quality drivers. I'm not set on a price, but I am looking for something with optimal sound quality for a music only system and do need something compatible with my higher than average crossover point. Thanks in advance!

Jerrod
 
I'd like as much extension as possible, but don't want to give up too much transient response to get there. I do have a brand new pair of Dayton Pro 18" drivers, but I'm looking for a little more extension than the typical high efficiency solution. Also, 12 cu. ft. is about as much size as I can tolerate. If I can come up with a workable solution in a smaller cabinet that would be fine too!
 
Max SPL for the upper horn is 110dB@1m?

Excursion-wise, 4 12" Dayton RSS315HF drivers in a sealed enclosure could potentially maintain a max SPL of 110dB@1m below 20Hz, assuming you place them on the ground for the 6dB floor boost. More, when you consider that the other channel would be reinforcing the bass as well, AND there would be room gain. What size is the room?

What's the sensitivity of the upper horn?
 
Hello!

Yes, as configured the max spl for the upper horn system is around 110 db if the 2.5 watt triode amplifiers are getting squeezed really hard. The horn section consists of a 10" JBL 2123J midrange loaded in a 12x24 conical horn, a JBL 2426J compression driver on a JBL 2370A biradial horn, and a JBL 077 slot radiator to fill out the top. The upper horn section is crossed
passively and averages just over 106 db 1w/1m. With different amplification it is fully capable of incredibly high output. The room is 14' wide, 24' deep, and 10' tall. At the rear of the room is the staircase and it's open all the way to the second floor ceiling. The left side of the room has a 6 foot opening adjoining to another room. It's pretty much open space without much potential for appreciable room gain. I built the bass horns to "keep up" with the upper horns. They do keep up, but response is pretty darn uneven making it difficult to integrate well with the upper horns. I wonder if a 18" JBL 2245H or 2242H, or perhaps a pair of 15" 2235H's would serve my needs better? I haven't found many high efficiency setups using low efficiency woofers. I do know that to maintain output down low will require adequate cone area, displacement, and horsepower. The Crown K2 is rated at 500, 800, and 1250w @ 8, 4, and 2 ohms. I've been thinking about solutions to my bass needs, but I'm strugling a bit with putting together the optimal plan. I'm hoping by posting, maybe some new ideas can be generated. Thanks for your thoughts.
 
In cinemas over here they use a pair of JBL 2226's below their midhorns, crossed around 500Hz. I've read of a few people using vintage Altecs with success too (the 515 driver seems popular)

These are both high efficiency drivers though.

fwiw I thought my adire tempests didn't sound too good above 40Hz.

If I was doing this I'd go for high eff drivers and use a mono sub below 40 - 50Hz.

What horn are you replacing ?

Cheers,

Rob.

Edit: my beyma lx60 15's measured pretty smooth up to ~250Hz, and were pretty musical too.(they are jbl 2226 copies though)
 
The horns are the Bill Fitzmaurice designed Tuba 36's. 36 x 36 x 30 with the vertical baffle. I finished them in walnut and maple to match the tops. One of these days I'll get the some new photos uploaded. The horns use a JBL 2226H woofer. I have four 2226J woofers and two Dayton 18" Pro drivers also. I should probably leave well enough alone and just listen to some music. The horns are super articulate with as much extension as you could expect. Still I find myself missing some of the music. If I'm going to make a change I'm really going to have to do my homework to avoid making a lateral move if not a downward one. The Dayton Reference idea is rapidly fleeting, but this is interesting:

http://www.tcsounds.com/lms4000.htm

http://www.tcsounds.com/lms5400.htm

http://www.tcsounds.com/padrivers.htm

A single 15" or 18" with the Crown K2 delivering 1000+ watts

Hmmm.......

J
 

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I'm not suprised you didn't get on with a folded horn used up that high. I'd never use my labhorns above 90 - 100Hz.

The 2226's model nice in a Q 0.71 sealed box, with a 12dB roll off right on the 80Hz / -3dB point. Then use the 2 18's to do mono sub duty below. Add a 12dB butterworth high pass at 80Hz to the 2226's, and a 24dB low pass on the 18's.

Thats where I'd start with what you have. The other thing I'd try is porting the 2226's at 40Hz, and crossing to the subs around 50Hz.

In all honesty I'd try adding a straight midbass horn to run ~70 / 80hz up to the midrange horn, and keep the fitz ones for subwoofers.

Cheers,

Rob.
 
Oh yeah!

Now your generating some ideas that I hadn't thought of. My biggest issue is size. The bass horns serve as the base for the upper horn section, so about the only direction I can go is up if adding more speaker components. I guess I was hoping to find a good solution to cover 20-160hz. I'm currently at a 4-way system, adding the midbasses makes it a 5-way with 6 channels of amplification. Still not undoable....the midbass section doesn't need much cabinet volume and could mount over the mid/hf horns. Add an amplifier, drop the crossover on the T36 and let it rip down where it's happy. The 2226's should be super clean and could let me raise the crossover point for the midrange horn as well. Two 2226's per channel mounted horizontaly above the current stack. Ported or sealed?

You might be on to something.......
 
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