Some questions about hornresp

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Ok a couple qustions. First is about phase. Do I want the phase at the "crossover"(between horn and direct) frequency to be as close to 0 as possible or as close to 180 as possible? or does it depend on whether the mouth is on the front or the back? And if so which way is which? and second do I want to match the spl of the horn with that of the driver because I've been getting some horn graphs that are 15-20db higher than the spl of the driver, and that would be hard to integrate in a RLH design. It would be nice if there was some general directions on how to utilate the results from hornresp for practicall aplication. Like maybe a tutorial or something. Thanks.

Also I posted some designs I came up with on another thread hoping for some knowledgable feedback and nobody that knows more than me about horns even responded. I really need some feedback because otherwise I'm stuck at my current knowledge level untill I can actually afford to build something and test it.

I have posted a few very simple questions that I've been trying to figure out and searching for answers for for months. I know a lot of you use this program and know the answers to these qustions, but no one has thought it worth their time to give me some simple answers. I thought that was what this forum was for. Please guys, help me out here.
 

GM

Member
Joined 2003
Wrong forum for HR for the most part, these two are more appropriate:

http://www.diyaudio.com/forums/forumdisplay.php?s=&forumid=63
http://www.audioasylum.com/cgi/etv.mpl?forum=hug

There's no doubt others if you search the WWW and you can always email David through his website, not to mention there's an on-going HR thread at the first link that pops up when doing a search of the DIYaudio site, so it makes me wonder just how much searching you did before deciding to be a 'squeaky wheel'.

For sure, trying to make me feel guilty for not responding quick enough to suit you when a simple 'ping' to bring your Q back up to the top engenders a < zero desire to help you.

Regardless, there's no BLH design tutorial AFAIK and the forum that me and others posted extensively on the subject was hacked/destroyed awhile back and I have neither the time nor interest in trying to redo it, especially considering all the folks that have popped up to try and capitalize on it, i.e. 'the few ruin it for the many'.

Not sure what you mean about XO phasing, but as me and others have repeatedly posted on this forum is that BLHs for 'FR' drivers are basically big vent reflexes (BVRs), so the vent's gain BW should only be enough to yield a ~flat response when combined with the driver's and room's output, ergo whatever phasing you're referring to will be whatever it takes to do this.

For a horn only BW design you go for all the efficiency you can IMO, so for a BLH, driver recessed 'x' amount in mouth based on the driver's specs and desired gain BW is best.

GM
 
I really have a hard time understanding the attitudes of some people on this forum. Answers to simple questions are impossible to find, and people with simple questions are treated with distain. You would think experienced designers who are at all involved in a forum would embrace people who want to learn from their experience. If I posted an inflamitory remark about some beloved driver or design I would have 20 posts the first day but if I have a sincere question on how to read data so as to come up with my own design I am all but ignored. And when I comment on it I get ostricized. I love this hobby and want to be part of the community but it seems to get to be a ******* match and people looking for recognition of there great genius or else an eletist club. I'm not trying to be a whiner I just really want to learn how to use this program and am having trouble finding out how to do it and who to ask. So I picked the forum I thought most relevent and asked my question. Two days later no response so I thought I'd try a little pleading. Now your making me feel like a jerk just for asking and an idiot for not knowing exactly who to ask or where to ask. I have spend hours, I mean like more than 20 hours in the last few months searching for the answers to these few questions. and from your response, it sounds like you don't even understand the question so how can you question hosw hard I'm looking for the answer. I'm not trying to staert a fight or even say anything bad about you just think about the tone of your answer. I'm just asking for help don't talk down to me it's extremely discouraging and this is supposed to be fun.
 
Ok a couple qustions. First is about phase. Do I want the phase at the "crossover"(between horn and direct) frequency to be as close to 0 as possible or as close to 180 as possible? or does it depend on whether the mouth is on the front or the back? And if so which way is which? and second do I want to match the spl of the horn with that of the driver because I've been getting some horn graphs that are 15-20db higher than the spl of the driver, and that would be hard to integrate in a RLH design. It would be nice if there was some general directions on how to utilate the results from hornresp for practicall aplication. Like maybe a tutorial or something. Thanks.
I am not quite sure what you are asking.
If you describe what your project-goal is, it might help...

In generall: Phase of two ways at the crossover point should be in such that it doesn´t cancel each other out as good as possible... You also have to take into account the distance of the drivers to each other... Using ONLY a simulation wihtout very extended theoretical background to come up with a correct phase behaviour and a passive x-over is next to impossible.. "Back in the days" we used our ears and maaaany x-over parts and a loot of time to get it right...
Later, I bought some measuring equipment :)

Building prototypes is necessary either way... So make some sawdust :)


"the otehr topic": Relax :) This is one of the most helpfull community on the planet - everyone is doing this on free time and David and many others (like GM) have been very helpful over years. No one is trying to make you feel stupid. Sometimes you have to be patient or rephrase your question...
 
I really have a hard time understanding the attitudes of some people on this forum. Answers to simple questions are impossible to find, ....

You would think experienced designers who are at all involved in a forum would embrace people who want to learn from their experience. ....

So I picked the forum I thought most relevent and asked my question. .....

I have spend hours, I mean like more than 20 hours in the last few months searching for the answers to these few questions. and from your response, it sounds like you don't even understand the question so how can you question hosw hard I'm looking for the answer.

Sooooo...

Not trying to be blunt but you need to understand a few things.

First, your question(s) were too vague, so it's impossible to give simple answers. Bring up a particular design and share what you tried to do with your reasons for that design, and answers will be more detailed. Please remember that audio is not simple. There are so many variables that's it's easy to get lost in all of them.

Designers who have spent their whole lives learning, trying and doing this stuff... they would kinda snuff at somebody asking them to reveal their life's knowledge in a single post. Many of them have had their ideas or even finished designs copied without a single thank you. So, yeah, I understand them to be a little cautious.

This forum is the FullRange forum.... Most of it is XO free, so maybe not the greatest place after all.

You said you have spent 20 hours in the last few months???
I've spent 20 hours in less than 3 days looking for answers. Loss of sleep, yeah! But that's passion.

Most of the experienced people here have spent their whole lives... years of searching, experimenting, failing and sometimes succeeding.

You still have lots of hours to go before even understanding which questions to ask.

If you're passionate about this stuff, keep reading.
Like Sabbelbacke mentioned, make sawdust. Try stuff. You will fail, and sometimes succeed. It's part of learning.

Nobody here will give you all their life long knowledge for free just because you want it now, without spending time on it.

If all that seems like too much, do realize that there are many here and around the web who will sell you kits or plans to build the exact thing you wish to have, without spending all those years learning about it.

Good luck!
 
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