I just wrote a huge write up of my speaker project. Dayton 12HF - Peerless 83075, Seas 27TDFC, active crossover.
http://www.mazprojects.com/audio/
Please comment, any newbies here should be able to learn something from it, veterans give me your opinion.
http://www.mazprojects.com/audio/
Please comment, any newbies here should be able to learn something from it, veterans give me your opinion.
Thanks for the notice, I fixed the pix and checked on another computer. Need to get a better page editor.
I'll just work now on moving to the equator so I can live with my speakers outside.
I may play with the hds exclusive to see if it can get closer to xmax without distortion, if I had the money I'd play with the skaaning sk170.
I'll just work now on moving to the equator so I can live with my speakers outside.
I may play with the hds exclusive to see if it can get closer to xmax without distortion, if I had the money I'd play with the skaaning sk170.
They are working now mazurek.
I must say that looking at the response graphs for the 12" DREF's, I thought there'd be more low end output. They look to have a -3dB of around 40hz. I assume from the roll off reate that these are sealed enclosures?
Do you feel that they go low enough for you at this time? Seems like you've got the potential to boost it up quite nicely with EQ and not run out of headroom easily. Or are you using a seperate subwoofer somewhere that does the really low stuff?
Just a thought related to my own rather perverted bass taste rather than anything else
EDIT:
I really should actually read the whole webpage rather than just looking at the pictures
I see you answered my question here:
"I played around with a Linkwitz transform circuit for the subwoofer, and I found that pushing the extension down to 25 Hz made the speakers more enjoyable. I will probably implement a physical one eventually, but it will reduce the volume headroom of the speakers and make them play closer to excursion limits (which is bad, you can subtly here the motor at excursion limits). Ultimately, when I get the time and money, I will go with 2 12 inch drivers per sub. I am playing them in a huge room, and don’t get much of a room gain"
I must say that looking at the response graphs for the 12" DREF's, I thought there'd be more low end output. They look to have a -3dB of around 40hz. I assume from the roll off reate that these are sealed enclosures?
Do you feel that they go low enough for you at this time? Seems like you've got the potential to boost it up quite nicely with EQ and not run out of headroom easily. Or are you using a seperate subwoofer somewhere that does the really low stuff?
Just a thought related to my own rather perverted bass taste rather than anything else
EDIT:
I really should actually read the whole webpage rather than just looking at the pictures
I see you answered my question here:
"I played around with a Linkwitz transform circuit for the subwoofer, and I found that pushing the extension down to 25 Hz made the speakers more enjoyable. I will probably implement a physical one eventually, but it will reduce the volume headroom of the speakers and make them play closer to excursion limits (which is bad, you can subtly here the motor at excursion limits). Ultimately, when I get the time and money, I will go with 2 12 inch drivers per sub. I am playing them in a huge room, and don’t get much of a room gain"
You got it ShinOBIWAN, I wasn't comfortable yet to design ported subs. They do only go down to 40 Hz. Its real clean though. I need to figure out a good way to put in a Linkwitz transform (I have a soft one set up for digital music, but nothing otherwise), I think I'll make a separate sub equalizer box, because I like the idea of keeping the subwoofer system separate from the main crossover, so I can change it or add even more subs without redoing the main crossover.
With the soft LT circuit, I would have 25 Hz as -3dB, one subwoofer should hit 101dB as displacement limit. The two are within half a wavelength so it should hit 107dB. I wouldn't say I have to have more subwoofers, but I get uncomfortable watching my subs going 1" peak to peak (I'll be so sad if I kill them). SPL meters confirm my room gets almost no gain, which is sad.
With the soft LT circuit, I would have 25 Hz as -3dB, one subwoofer should hit 101dB as displacement limit. The two are within half a wavelength so it should hit 107dB. I wouldn't say I have to have more subwoofers, but I get uncomfortable watching my subs going 1" peak to peak (I'll be so sad if I kill them). SPL meters confirm my room gets almost no gain, which is sad.
I have a better idea. Lets put him on Jupiter so he can pick up some metallic hydrogen http://www.diyaudio.com/forums/showthread.php?postid=872897#post872897
I figure we could combine cotdt's hydrometallic/crazy diamond cones with Feandil "I ruined my moms ebay account with fraudulent speaker claims" Audiophilenoob's 22mm xmax motor.
Think of the possibilities! The internet is such a wonderful place indeed! I really got my money's worth today.
BTW, cotdt, what happened to your one time absolute fascination with hemp cone drivers? That was one thing that seemed to make actual sense. Too bad. Gotta run...
cheers,
AJ
p.s. Pinkmouse, you're such a party pooper. Just when threads start drifting into the twilight zone, you intrude with reality! Shame, shame
I would have used the hemp drivers but already settled on a midrange. Now i'm going to mod my mids with a new cone. which will probably be diamond. but you won't be interested since all you care for are poly coned mids with coaxial tweeters.
good things are happening though! i've been doing research for future plasma tweeters which will blow everything away.
good things are happening though! i've been doing research for future plasma tweeters which will blow everything away.
AJinFLA said:
I have a better idea. Lets put him on Jupiter so he can pick up some metallic hydrogen http://www.diyaudio.com/forums/showthread.php?postid=872897#post872897
I figure we could combine cotdt's hydrometallic/crazy diamond cones with Feandil "I ruined my moms ebay account with fraudulent speaker claims" Audiophilenoob's 22mm xmax motor.
Think of the possibilities! The internet is such a wonderful place indeed! I really got my money's worth today.
BTW, cotdt, what happened to your one time absolute fascination with hemp cone drivers? That was one thing that seemed to make actual sense. Too bad. Gotta run...
cheers,
AJ
p.s. Pinkmouse, you're such a party pooper. Just when threads start drifting into the twilight zone, you intrude with reality! Shame, shame
mazurek said:
Take a look at the ESP P71 Linkwitz Transform PCB:
http://sound.westhost.com/project71.htm
Those are easy to build. Rod offers detailed construction plans if you purchase the PCB.
Use this spreadsheet to calculate the correct value's for the resistors and capacitors required. This is all based on you inputting the TS parameter for the 12" DREF's and also the enclosure volume. Looks complicated but it isn't.
I can't wait. Between you and the Feandils of the internet world, driver design appears set to make quantum leaps forward. Makes perfect sense. I can only imagine that the soon to be unemployed engineers at SEAS, Scan-speak, TAD, Adire, et al are simply watching in awe. I know I am.
Hey remember your idea and questions about a waveguide for your plasma tweeter? Have you considered one made entirely of diamond? That might work.
A hemp waveguide wouldn't last too long, but you really wouldn't care after a minute or two. I'd be careful with that hydrogen business, or you may really end up blowing stuff away.
Oh yeah, almost forgot, Mazureks thread. Aren't the speakers a bit close together?
cheers,
AJ
cotdt said:
Isn't cotdt the fella that needed so much help designing an under $100 speaker earlier this month and after 5 pages of people's suggestions and his rejections, he then mentioned that the $100 had to also include amplification?
This guy goes from being unable to design a low-buck gift speaker to a Materials Engineer, able to design breakthrough diamond cones in less than a month. Perhaps we can get a virtual autograph from our next Einstein before the collector's market jumps the price.
Ok, I'm just envious, back when "I" was 17 and knew everything, I should have introduced all kinds of fantastic inventions. I'm sad to report that time and reality has had a detrimental effect on my genius.
Best Regards,
Terry (Tesla)O
AJinFLA said:
Haha, you guys can have your fun with it, at least it keeps it near the top so people can see it.
Yeah, the room is one of those condo living room/kitchen/dining room rooms, so I am doing my best to fit the theater. Acoustics are ok, but it has some mild unfixable bass dropout issues. I'm all for practical music enjoyment though.
cotdt said:
Great... why even bother mentioning anything in the first place?
Were you expecting all the girl's to come running out and give you a big kiss on the backside?
With things like self proclaimed 'grand innovation' one way admiration and respect from your peers is earned is through proof. You may feel that you have nothing to prove and that's fine also but just don't expect anybody to take much notice in the meantime. Unless of course you already have considerable credentials ie. Scanspeak turned around and said they've developed a new motor that outperforms all previous generations.
BTW: Sorry mazurek, this has little to do with your project. What do you think to the ESP P71 LT circuit I linked to earlier?
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