Rerurn to Romy the Cat's Site

Actually it is very interesting question and I almost feel you pain for decision you will be making. I do not think that anyone would be able to express any arbitral opinion about the subject, as least an opinion that worth to follow. You see, building such a system is a self-contained creative process and it I will include many wrong decisions that you most likely will be dong. Those wrong decisions are perfectly normal and not one will underused your “mistakes” accept you. Navigation sound in that that type of installation is a process of DOING THE THINGS, then observing the results and REACTING UPON THE RESULTS. I do not believe that there are people who can foresee the results in this type arrangement as you are planning to build. I will pass some of my very general observations but please take them with certain skepticism. First of all I never built those types of installations and second: I do not fell that any generalizations in your case worth consider as a “doctrine”.

Generally I do not believe in bass horns. There two major reasons (there are some minor as well): time alignment and the bothering me “closed bottom”. With time alignment is simple: I just do not know how to delay a full range signals to synchro it with a few milliseconds of delay that happens in a bass horn. The second reason is more complicated. The sealed enclosure I call “opened bottom” enclosures. What I mean is that there are no conceptual limitations in lower response. The limitations in sealed box are tactical: how much power you have, how much your drivers will handle, what is the relation of volume and Fs, how driver damped by amplifier and many others. However, there is no self-restricting boundary in there. With any other LF solutions (horn, open baffles, 4th order, ported and so on) there are always strategic limitations by nature of the design… would it be size of the baffle, size of the mouth or tuning of a port). With sealed box you can always burn some power, use the LF section on transition slope or even EQ (with open bottom only) your bass (works very well). With any other solutions (besides sealed box) those “further actions” are not available. Those are some of my motivations why I do not like the idea of bass horns and prefer the sealed enclosures

Saying it I have to add that the “recommendations” would also vary with the level at witch you target. If you look to get a pressure rising at LF (it is hoe most of the bass horn sound on bad hand) then any bass horn will do. It is very easy to get that “sewer pipe type of bass“ from a bass horns… the question what to do next? No one knows. The Morons are deaf do not recognize that they have that “sewer pipe type of bass“ but even when the do  recognize then who the hell know how to fix it? Not to mention that fixing implies a large cement mixing machine and a wasted half of summer. Sounds like a plan for actions, doesn’t it? Sill, I have to add that if the bass horn and a sealed enclosure are done IDENTICALLY PROPERLY then for the SAME FREQUENCY the bass horn do sound better.

Saying that I do admit that you are absolutely correct saying that it is a lifetime decision. You will never do it twice and therefore here is the rational that I would consider if I were at your place: I can always threw a pair of sealed arrays in my listening room, however I will not be able to add bass horn AFTER I made my barn conversion. So, you might find a reason within yourself to go for bass horns and if the bass horn direction will not deliver to you the results that you would like THEN discard the project, make a good sauna in those horns and put the sealed array into the game. A intestinally do not expires a direction I would go personally if I were you – it will be your call.  However, I will give you some point for both directions.

Sealed array will work ONLY across a long wall. While thinking about the arrays and the drivers think about amplification. The amplification-drivers interaction in high-quality dedicated LF sections sis very much under-looked area. Consider multi-sectioned arrays with one driver per section. This also economical as you might start with less sections and then pile them up as you find it necessary. The arrays must be positioned outside of your MF sections.

In case of the bass horns let visualize what we deal with. If for instance you go for 25Hz horn with 18” throat then (for tractrix profile that you would likely NOT wiling to use) you would need roughly an exit area of 150000 sq cm, which is a circle with 4.3m diameter or it’s square equivalent. The horn will be around 9m, with ~ 9mSec delay (depends of the temperature outside… unless you will thermo-stabilize the horns :-) Further, any serious solution implies use of TWO HORNS. The mouthed of the hone must be outside of your MF sections. You might position the mouths of the horns at the side’s of the barn and by doing it you will minimize the time delays. It is a VERY good solution but having 23 by 33 feet room you have no space to play with it is you do for 25Hz horn. The image below will give you an idea how it might be done:

However, if it delays might be fixed as it shown above then it will set the entire system to operate in far-field setting. You have to consider it and see is you like the far-field arrangements (I do not). Also, the position of mouths of the horns near a middle of the room and near the listening position do resolves the delays problem but at the same time do creates some other troubles.

So, as your see there are a lot of thing to consider. Not the last would be your thoughts about the rest of loudspeakers that will be using and how they will be integrated in context of your ether line-arrays or the bass-horns. I can only promise you what whatever decision you will go for you will be sorry.. :-) Nevertheless, there is a slight mercantile advantage to go for the bass horns. After you finish the project you can make some money by selling admission tickets into your barn to those crazy British audio-freaks demonstrating to them and to their wifes that … “it could be worse”…

Rerurn to Romy the Cat's Site