12" Midbass Horn

I was thinking of a 4-way setup using 2405, 2445, two E-120´s and 2245 for the low end.

This shell be a mainly hornloaded system, so I´m wondering if there is a proven design for a midbass horn that will fit two 12" woofers?
I don´t recall any jbl or altec cabinet for 12", they all seem to be made for 15"...

The 2445 would be mounted to a yuichi horn and I would targed a crossover of about 800hz. What I have located so far is a stage acompany 12" horn, but that has a very narrow horizontal dispersion of 60°, whereas the yuichi 2" horn has 90° and this wouldn´t match very well...
Besides that, I know from tweeterhorns that you always have to set the actual crossover-point at least double above the physical horn-cutoff. For example, the yuichi has a cutoff of ~300hz so you should crossover above 600hz...
In case of a JBL 4560 woofer-horn that loads effectivly above 200hz, would I have to crossover at 400hz??

Would you recommend a midbass-horn for home-hifi or is this a bad idea?
How does such a setup compare to a 10" or 12" in a sealed enclosure as used in the famous studio monitors such as 4355?
I have experience with the 2123 in 0,5cubic feet sealed at home and wonder how it compares to a horn. I have owned a 4560 horn, but don´t know how this behaves in a living-room.
Where is the drawback of a midbass-horn at home?

Looking forward to hear your ideas :-))

Hi;

A couple of thought and observations:

A single horn loaded E120 and your 2445 will easily run away from two 2245's as far as volume is concerned.

I have a horn loaded stack that has one Community M80 mid bass horns with a JBL 2020H in it. These are on top of Boxer Bass horns with two JBL 2240's in each. The HF is a 2441 on a RH60 radial horn, 60 degree. I love part numbers that mean something.

Crossovers are at 250 and 800Hz. The 2020's definitely play a part but they keep up so easily I can't imagine using two 12's unless you wanted serious output at like 100Hz. You would want them vertical to keep some horizontal dispersion.

What are your plans for this system ie how loud and how low?

Barry.

Barry, don't you also have a pair (or is it two?) of peavey MB1?
That one looks so impressive with the phasing plug and all :coolness:

Hi Thomas!

I did have four of them. I thought they looked so cool and they looked like they would be awesome but I could not get happy with them, at all.

I ran caps and cones in near contact with the phase plugs and made spacer rings to incrementally move the drivers away. I thought it must be the Peavy drivers so I tried 2202's, 2204's, 2206's and 2020's in them and decided that they weren't for me.

I GAVE them to Carl Huff who went through the same routine and gave them to someone else.

Too bad! In my mind they are one of the coolest looking horns ever, but I can't use them.

All the best!
Barry.

Thanks a lot for your replies!

The main goal of this project would be sound quality, not sound pressure. I´m aware that one E-120 per side would be easily loud enough, even without the horn.
My idea of the double 12" horn was to increase the hornmouth and lower the actual cutoff-frequency of the horn.
An enclosure with two 15"s would be too big...
And I think two E-120 could sound better than a single E-130, what do you say? They should have aprox. the same cutoff, but the 12"s should have even more dynamic attack...

Quote:

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Originally Posted by Dr.db

....Would you recommend a midbass-horn for home-hifi or is this a bad idea?
How does such a setup compare to a 10" or 12" in a sealed enclosure as used in the famous studio monitors such as 4355?
I have experience with the 2123 in 0,5cubic feet sealed at home and wonder how it compares to a horn. I have owned a 4560 horn, but don´t know how this behaves in a living-room.
Where is the drawback of a midbass-horn at home?...

---

Not a bad idea at all. A properly horn loaded E120 will smoke a 10-12" direct radiator on impact no question.

2123's are great for sure. My favorite high power 10" midrange.

Thinking about the 4350-4355 as compared to a 4343/4345 a ten and one inch compression driver will keep up with one woofer and is a balanced approach. JBL had to use two 15's and a 12 to really get loud enough to utilize a large format compression driver in a real large format studio monitor.

I have a theory as to why JBL used a 10" in the afore mentioned studio monitors and some of the Cabaret models when to my ear a 12 would have made more sense. Many small spaces, clubs and live performance spaces are naturally awash in mid bass mode driven stored energy (mud) and having a scooped response in the mid bass results in a better overall sounding space. Clair S4's were 18's to 10's too if I remember correctly.

I hope you do this. My M80's are also narrow in the horizontal for home use so I am interested to see what you come up with. Honestly an easy conical should work well for this alplication don't you think?

Do you plan on using any compression?

Where do you plan on crossing the 2245 to the E120?

Barry.

Lot of input, thank you...

Crossing of the midbass-horn to the 2245 would be somewhere between 100-200hz, depending on the horn-cutoff. The lower the better I assume...

I have loved horns for a long time and I´m shure a hornloaded E120 will outperform a 2123 in dynamic attack with ease.
But I´m wondering if a double E-120 horn will sound as audiophile as a single 2123...?? They have to play up to 800hz and running two cone´s in the same frequency range could be a problem!?

Attached is an extract from the book "Acoustics" from Leo L. Beranek. Originally the plot is from a book of Harry F. Olson, "Elements of Acoustical Engineering".

Mouth size determines the magnitude of resonances, horn length determines their position. Cutoff frequency must fit, you cannot simply make it lower cause that would make your horn too large.

Ruediger

Thanks a lot for your technical input.
Actually I don´t want to start a new horn from scretch e.g. build a new design. I rather want to stick to a proofed design that allready exists.