Quiet_Hollow Posted July 16, 2014 Share Posted July 16, 2014 Here is the THT in half space: "Here's a chart with a line." uh... C,mon. Now wheres the voltage and the rest of the associated data regarding the measurement? You, of all people, know better. Measure the voltage. In a comparative context, SPL numbers are nearly useless without it. Yes, the THT doesn't pave any new ways in the horn sub category, but what's most often left out is that neither does anyone else's FLH design. Where voltage and displacements are concerned, they all end up within a dB or two of one another. In addition...where subwoofers are concerned, flat response out of the gate is as useless as a white crayon and (I can't believe I have to repeat this in a Klipsch forum) THD is not the primary (and certainly not the sole) comparative metric. If you like the THT, then I'd also recommend a Khorn bass bin, or even perhaps two... Chris, not even close. This one requires first hand experience. I'll spare any name dropping, but it's not like I haven't been around the block with subs either. PM me if you'd like to stop by for a listen sometime. We can knock a few paintings off the walls, tear up some plaster, and piss off the neighborhood together...then finish off by rolling right into some Brubeck or Krall. 2 Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 16, 2014 Share Posted July 16, 2014 You do realize I included a link to more data right? And there you will find a link to the thread where the measurements were taken and the SPL's / voltages were explained....I grow tired of rehashing the same information over and over again. So what really are you so hostile about? Nowhere have I said you couldn't enjoy a THT. I have only stated that there are better designs available. Do you disagree? Ricci has put together a huge list of DIY options that have all been measured in the same fashion. Here is a sorting of that list on the performance in the 20-80Hz range: http://www.data-bass.com/data?page=systems&col=7&type=1&sort=desc&mfr=-1 Do you really contend the THT will be at the top of that list? I'm certain it will not. Based on the other subs compared in the link I provided, I'd be surprised if the THT kept up with the JBL4645c (16th in that list). The SRX718 is a step down from the 4645c and that was one of the better contenders in the comparison measurement I referenced. Here is that summary (also available in the link, but apparently some like to be hand fed): Orange - SRX718Blue - T30Pink - T39Green - THTPurple - Growler 1 Quote Link to comment Share on other sites More sharing options...
jason str Posted July 16, 2014 Share Posted July 16, 2014 Btw, I see Jason is an "Authorised builder in Chicago" over on the BFM forums... Just trying to make a honest living, i have bills like everybody else. 1 Quote Link to comment Share on other sites More sharing options...
Sancho Panza Posted July 16, 2014 Share Posted July 16, 2014 ^^^ DrWho, I don't he's ever hidden that fact. Nevertheless, your info is interesting, too, thanks. 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted July 16, 2014 Share Posted July 16, 2014 The F-20 is just a THT knockoff and the unbraced 3/4" plywood would have more distortion than the THT as the lack of bracing contributes to THD, you get what you pay for. Why would you think It's a THT knock off? If it is indeed a knock off, lilmike did a great job as it's so much easier to build than any of Bills subs. The only unbraced F-20's I've seen were some of the prototypes and test rigs. Virtually everyone braces theirs that I've seen. 2 Quote Link to comment Share on other sites More sharing options...
jason str Posted July 16, 2014 Share Posted July 16, 2014 The F-20 is just a THT knockoff and the unbraced 3/4" plywood would have more distortion than the THT as the lack of bracing contributes to THD, you get what you pay for. Why would you think It's a THT knock off? If it is indeed a knock off, lilmike did a great job as it's so much easier to build than any of Bills subs. The only unbraced F-20's I've seen were some of the prototypes and test rigs. Virtually everyone braces theirs that I've seen. LiLmike purchased the plans and never built the THT, it was just refolded in an upright position and used 3/4" material without braces. I noticed it is now recommended you brace the cabinet (witch is a good idea). 2 Quote Link to comment Share on other sites More sharing options...
jason str Posted July 16, 2014 Share Posted July 16, 2014 (edited) You do realize I included a link to more data right? And there you will find a link to the thread where the measurements were taken and the SPL's / voltages were explained....I grow tired of rehashing the same information over and over again. So what really are you so hostile about? Nowhere have I said you couldn't enjoy a THT. I have only stated that there are better designs available. Do you disagree? Ricci has put together a huge list of DIY options that have all been measured in the same fashion. Here is a sorting of that list on the performance in the 20-80Hz range: http://www.data-bass.com/data?page=systems&col=7&type=1&sort=desc&mfr=-1 Do you really contend the THT will be at the top of that list? I'm certain it will not. Based on the other subs compared in the link I provided, I'd be surprised if the THT kept up with the JBL4645c (16th in that list). The SRX718 is a step down from the 4645c and that was one of the better contenders in the comparison measurement I referenced. Here is that summary (also available in the link, but apparently some like to be hand fed): Orange - SRX718 Blue - T30 Pink - T39 Green - THT Purple - Growler What driver was used for the THT graph ? Can you list the driver or at least give us the T/S. Must be out of specs by the looks of things. How wide was the cabinet ? Was the driver sealed properly & tested for leaks ? Edited July 16, 2014 by jason str 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted July 16, 2014 Share Posted July 16, 2014 LiLmike purchased the plans and never built the THT, it was just refolded in an upright position and used 3/4" material Is this speculation on your part or is this something he said he did (refold Bills design)? 1 Quote Link to comment Share on other sites More sharing options...
jason str Posted July 16, 2014 Share Posted July 16, 2014 LiLmike purchased the plans and never built the THT, it was just refolded in an upright position and used 3/4" material Is this speculation on your part or is this something he said he did (refold Bills design)? If you have a copy of the plans have a look for yourself. 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted July 16, 2014 Share Posted July 16, 2014 So speculation then. 1 Quote Link to comment Share on other sites More sharing options...
jason str Posted July 16, 2014 Share Posted July 16, 2014 So speculation then. I cannot post a copy of the plans for the THT, if you don't have one i cannot help with this comparison. If you have a copy just follow the measurements of the horn path. 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted July 16, 2014 Share Posted July 16, 2014 I just can't help but think that if someone ripped Bill off, he'd go after them for copyright infringements. Certainly either he's seen the F-20 build thread or one of his minions has. 1 Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted July 16, 2014 Share Posted July 16, 2014 F-20 builds seem to have tapered off in favor of the MicroWrecker. It just may not be worth the time and effort (to build new, or knock down doors for existing) 1 Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 16, 2014 Share Posted July 16, 2014 F-20 half space frequency response: Here is BFM's advertised 1/2 space measurement: The F-20 is basically +/- 3dB from 20Hz to 90Hz with a non-sloped (flat) response. I'd argue that 20Hz is 3dB down. The THT is basically +/- 6dB from 20Hz to 90Hz and has a general falling response. Even with the advertised corner loading you're looking at 12dB down at 20Hz. If they're the same design, then why does one have a flatter frequency response that digs lower? 2 Quote Link to comment Share on other sites More sharing options...
jason str Posted July 16, 2014 Share Posted July 16, 2014 F-20 half space frequency response: Here is BFM's advertised 1/2 space measurement: The F-20 is basically +/- 3dB from 20Hz to 90Hz with a non-sloped (flat) response. I'd argue that 20Hz is 3dB down. The THT is basically +/- 6dB from 20Hz to 90Hz and has a general falling response. Even with the advertised corner loading you're looking at 12dB down at 20Hz. If they're the same design, then why does one have a flatter frequency response that digs lower? If I'm not mistaken those graphs were taken with the older recommended Adire Tempest 15, the F-20 should be loaded with the Dayton RSS390-HF-4. The frequency response of the THT gets flatter the wider you build it, custom tailor your cabinet width to your room gain needs. Could you answer the questions i asked in my last post to you about your readings please to determine where the problem lies. What driver was used for the THT graph ? Can you list the driver or at least give us the T/S. Must be out of specs by the looks of things. How wide was the cabinet ? Was the driver sealed properly & tested for leaks ? 1 Quote Link to comment Share on other sites More sharing options...
Chris A Posted July 16, 2014 Share Posted July 16, 2014 I believe that I'm getting the picture. If you want my consideration for audio components, especially subs, then I don't need secrets. If that information costs, then there are many other designs that suddenly look better to me. PWK had the right idea... Chris 1 Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 16, 2014 Share Posted July 16, 2014 To be fair Chris....BFM doesn't sell the subs. He's in the business of selling the designs for a very small price. I think it's like $15 or something. I don't know how long he's been doing this, but apparently there is a list of authorized builders for those that don't have the means to build themselves. Definitely an interesting business model. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted July 17, 2014 Share Posted July 17, 2014 F-20 builds seem to have tapered off in favor of the MicroWrecker. It just may not be worth the time and effort (to build new, or knock down doors for existing) I've actually been thinking about building a Microwrecker. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted July 17, 2014 Share Posted July 17, 2014 I meant Lil Wrecker. 1 Quote Link to comment Share on other sites More sharing options...
Chris A Posted July 17, 2014 Share Posted July 17, 2014 To be fair Chris....BFM doesn't sell the subs. He's in the business of selling the designs for a very small price. I think it's like $15 or something. I don't know how long he's been doing this, but apparently there is a list of authorized builders for those that don't have the means to build themselves. Definitely an interesting business model. Thanks Mike. Note that my objection is not due to the business model, but only that the information other than the build plans themselves, such as horn segment lengths, T-S parameters of the driver, throat and mouth sizes, and FR plots--in other words, the information needed to simply fill in Hornresp input record--are also considered "secret". Chris Quote Link to comment Share on other sites More sharing options...
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