[Hallicrafters] RE: Why is the R-42 speaker so expensive?

[Julian Bunn]

Bob and I have been discussing this offline: it looks like I am 
mistaken. Although mine
doesn't have a back, the R-42 as delivered does ... which would make it 
a closed box
design. I stand corrected! Thanks Bob!

So now I am in search of the back plate to an R-42 ... perhaps I should 
make one out
of plywood - how hard can it be?

Julian

Julian Bunn wrote:
> Yes Bob, you are absolutely correct about speakers in general, but I was
> not speaking in general, I was talking specifically about the R-42. 
> The R-42
> is essentially an open box design.
>
> Julian
>
> Bob Young wrote:
>> Cabinet design has a huge impact on the sound of a speaker. A bass 
>> reflex cab is tuned somewhere at or above the resonant frequency of 
>> the driver inside, they are much more efficient and have much better 
>> bass response than an open back cab with the same driver. These cabs 
>> take the back wave of the driver and put it in phase with the front 
>> wave and release it through a port usually below the speaker in front 
>> reinforcing the bass. Open back cabs cancel most of the lower bass 
>> because the back and front waves are out of phase with each other, 
>> ever listen to a driver that is not in a case, no bass at all due to 
>> out of phase cancellation. The only draw back to a bass reflex 
>> speaker is they drop off rapidly below the resonant frequency of the 
>> port. Sealed speakers sound even better as their drop off is much 
>> more gradual, but they are less efficient as they pretty much keep 
>> the back wave right in the cab itself. Many different cab designs. I 
>> don't know if this is anything to do with the price however.
>>
>> Bob
>> KB1OKL
>>
>> Message: 4
>> Date: Sat, 29 Sep 2007 18:42:17 -0700
>> From: Julian Bunn <Julian.Bunn at caltech.edu>
>> Subject: Re: [Hallicrafters] Why is the R-42 speaker so expensive?
>> To: jeremy-ca <km1h at jeremy.mv.com>
>> Cc: hallicrafters at mailman.qth.net
>> Message-ID: <46FEFEF9.4020302 at caltech.edu>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> I think the sound is good simply by virtue of the size of the driver.
>> The cabinet probably has
>> minimal or no effect on the acoustics, IMHO.
>>
>> No idea why they are so expensive ... I picked mine up very reasonably
>> from a chap who
>> was selling an SX71 and it came with it.
>>
>> Julian
>>
>>
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>