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In the Forum: Horn-Loaded Speakers
In the Thread: Problems with horns: upper bass
Post Subject: On 40Hz vs. 90HzPosted by Dresden on: 11/13/2008
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I know many would view the two frequencies as similar and perhaps of little consequence, but I have my reasons.

My primary, driving objective for wanting the horn to produce sound faithfully to at least 90Hz is that 90Hz represents an ideal crossover frequency when using with a subwoofer system (I prefer to not use a subwoofer above this frequency).  If the horn reproduces down to 90Hz faithfully, then I will be forced to use a subwoofer in order to render the remaining spectrum satisfactorily.

On the other hand, if I'm able to achieve a 40Hz cutoff, said cutoff being reproduced faithfully by the horn, I will forgo the subwoofer (I can live without the 20Hz to 40Hz range).  The 40Hz cutoff would be great, since the horn will then be reproducing a great part of the target spectrum, and as I noted before, it will save me the trouble of having to mate a subwoofer (never mind having to first design and then build it first).

Maybe it's the few years I spent as a sound engineer for theater (eons ago), but the difference in bass reproduction as it pertains to 90Hz vs 40Hz is very real, very palpable to me.  It may be small on paper, but acoustically, the attaining the 40Hz lower range is what that 'smooth, effortless bass' sound I mentioned is all about (at least, I believe it is a critical factor on how the quality of the reproduction will be perceived).

Of course, I could be wrong.  Just speculating--without even taking a very critial look at the dimension of the mouth of the horn I've designed thus far--it looks like the range will not be 40Hz, but more closer to 70Hz.  But 70Hz, if reproduced faithfully, with a slow roll-off at 60Hz, I believe will sound amazing (should everything else work accordingly).

In the end, (at the very least), the horn should be able to reproduce 90Hz faithfully--I'll consider achieving faithful reproduction to a higher cut-off a failure (which will prompt me to walk away before I return with a sledge hammer and 'put it to rest'.  [okay, just kidding on that last one--I will probably save it for use as my coffin, or urn.  okay, also kidding.]).


 Romy the Cat wrote:
Yes, the Dresden’s talk about 40Hz horn and 90Hz horn as the similar horns, particularly if he does not want to "cheat", stroked me as odd too. 90Hz horn is a nice a manageable 40” piece of furniture. The 40Hz is the monster in a house and a good reason to divorce for some women. Also, it VERY hard to differentiate between the “accurate, smooth, full-bodied sound” at 40Hz and 90Hz as at those frequencies the location of the horns (The Macro-Imbedding) and the construction of the horn become too important. I ran 125Hz horn and am getting out it 95Hz in “hot spot” (not the best way to do the thing BTW), so God knows what Dresden will get with a hole 4 time larger. Still, unquestionably the 40Hz is WAY more powerful weapon to fight for good sound. I also do not at ease with notion that the low-passing of long horn is too bad. It is most likely Dresden’s will have a MF channel at 500-600Hz that will decay very fast. Still most of the bass drivers in a straight horn will shoot with excessive HF and the low-pass of a long horn will be good remedy against using a high order low-path crossover on bass channel.

The Cat

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