| Larin |
Anybody know if this unit could do well in a "small" closed box?
I'm currently using a school computer and i'm not allowed to install programs so i can't model it myself:( .
I'm thinking of trying this unit in a d'appolito config with vifa xt25.
I really would like to try a for a speaker with freq.resp. 60-80 hz to 6k-8k (wide)mid and a natural roll-off, and then cross in the tweet.
Any thougts/suggestions? |
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| DrewP |
A 12.5 litre volume (plus the size of braces and driver magnets etc) will give you -6dB @ 74Hz. -3 @ 93Hz.
This is box response only so if driver output is different you'll need to add or subtract that of course.
Group delay is good though. about 4ms in the bass.
FAST
Drew |
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| kelticwizard |
If you want to go the vented route, a 24 L box tuned to 55 Hz will give the two woofers a -3dB down point of 62 Hz-right in your range.
A 76mm diameter vent of 124 mm length will tune the box to the required 55 Hz. |
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| pinkmouse |
| quote: | Originally posted by Larin
I really would like to try a for a speaker with freq.resp. 60-80 hz to 6k-8k (wide)mid and a natural roll-off, and then cross in the tweet.
Any thougts/suggestions? |
The HM170C0 has a nice smooth response, with a 12dB/octave ish roll off starting at around 5.5k, so it should work well in this application, though perhaps with a little lower XO than you were thinking of.
Kelticwizard's box size and porting seems right in the ballpark from my experience;) |
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| Larin |
Well it seems vented is the way to go even though i was hoping to avoid that.
Thing is i've read somewhere that the ear is most sensitive in the 100-5k hz region and that is also where most voices and instruments reside. i want that coverd with one driver. By placing x-over point well outside this i was hoping to minimize the db-drop in this area. And i was thinking of using a sub. I've also read that the ear is nondirectional below 80 hz, so one sub shold suffice there, if i cold get the mains to go that low.
I was hoping to use the drivers natural rolloff, and a 12db/octave rolloff starting at 5k5 hz would be good. then i could use only a cap to cross in the tweet right?I've been looking at many drivers(jordan,bandor,audax,vifa,seas and more) but i may have missed some, so if anyone know of a good driver suited for this let me know. |
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| pinkmouse |
Larin
I can't do a model for you, as my laptop with all my simulation software is on loan to a mate at the moment, but I'm sure that the Audax would work fine in a sealed box, ( sorry, I would have done this when I replied the other day, but I didn't read your first post properly).
Your idea for a sub should work well, you could possibly even go a little higher if you need to, but I'm sure the Audax drivers in a reasonable sized box would get down to 90hz or so.
As for the crossover, you may need to use a higher order on the tweeter, to match the 12dB rolloff of the HM170, but then again, you could always just try first order, and see if you like it!;)
What sort of budget do you want to spend on a tweeter? |
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| Bose(o) |
| quote: | Originally posted by Larin
Well it seems vented is the way to go even though i was hoping to avoid that.
Thing is i've read somewhere that the ear is most sensitive in the 100-5k hz region and that is also where most voices and instruments reside. i want that coverd with one driver. By placing x-over point well outside this i was hoping to minimize the db-drop in this area. And i was thinking of using a sub. I've also read that the ear is nondirectional below 80 hz, so one sub shold suffice there, if i cold get the mains to go that low.
I was hoping to use the drivers natural rolloff, and a 12db/octave rolloff starting at 5k5 hz would be good. then i could use only a cap to cross in the tweet right?I've been looking at many drivers(jordan,bandor,audax,vifa,seas and more) but i may have missed some, so if anyone know of a good driver suited for this let me know. |
For myself, I had the same idea and modelling with a first order cross over @4000Hz. you would still get a similar result and throught my experience with the HM130Z2, you definintly don't want that larger spike in response common to these Audax drivers. The sound is very clean, fast and accurate, I have never heard Kenny G's sax sound so real with such a correct reed 'bite'. Very beautiful sounding drivers, hope you have fun!
In addition to the crossover point, I originally chose my point for pianos, because after hearing so many speakers distort because the sound of the piano carries into the tweeter, I hated that so much that it was my primary goal for the piano not to sound unnatural! |
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| MarkMcK |
This driver has been out for a while now, and this thread is over a year old. Do we have any listening evaluations of the driver? While bass response is important, the midrange sound is just as important. Does anyone have impressions of the midrange performance?
The reason I ask is that, although the driver is much better in stock condition than the others I have been modifying (markmck's tang band mods), this driver has several cone breakup or vibration mode problems. I also have a modification for this driver that can be done by the average diyer that will dramatically improve performance from the mid bass to about 5.5 kHz. The modification takes care of the three vibration mode peaks and includes a steep slope low pass filter that would cross at about 5.5 kHz.
Lastly, since Parts Express sells this driver, I was considering submitting the modification to their project showcase. Is this somewhere diyers go to check for projects?
Mark |
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| andrikos |
Hey Mark,
If it means anything, I look for projects here! :) |
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| MarkMcK |
Andrikos,
And I have posted several projects to this forum. Still, not every diyer is a member or views this forum. I like it when the pictures and graphs just pop up in the thread. I really don't like having to click to view. I understand why this change was made and that is okay. Most of my recent posts have linked to my own Web site. One way to save both my Web site bandwidth and save diyAudio bandwidth is to use Parts Express site and then just link to it. The content I post there would pop up here. I believe I could both include modifications here and there in a one stop kind of thing.
Also, for that use (or used) this driver, have your impressions changed over the last year or so. One person really gushed over the sound of piano and sax using this driver, has that changed any?
Mark |
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| MarkMcK |
I sent my HM170 modification to Darren at Parts Express today. I will let you know what they are like to work with. Hopefully there lead time to publication is less than AudioXpress.
Mark |
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| Bose(o) |
| Sax and piano still good? Check and double check. |
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| MarkMcK |
| quote: | | Sax and piano still good? Check and double check. |
That is good to hear and is good to hear! With the modification, the back wall of the soundstage goes away, everything opens up, and the piano is just there in the room with you. Also, everything else is great too, including female vocals.
Anyway, a quick update on the Project Showcase submission...My submission generated an "are you real or are you spam" automatic reply. I followed the instructions to "register" my e-mail in Parts Express "white pages" and resubmitted.
No spam reply this time. Now it is up to Darren, who, by the way, is developing quite a reputation for silence.
Mark |
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| MarkMcK |
Darren replied today. They will not be posting the project.
Oh well, I may just post it to my own Web site as a curiousity and for interest of those who still have the drivers or may buy them used.
Mark |
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| MarkMcK |
I checked the PE Web site and they have updated the status of the HM170CD driver. The reason they gave me for not wanting my modification project was that Audax would no longer supply the driver.
If you have the driver already, this is still an easy and worthwhile project.
I have just posted the modification instructions to my Web site. Just use the button at the bottom of my post and go to the "driver modification" page.
Good designing and good building,
Mark |
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| RSQ8P |
Anybody have the mod instructions? Would like to do it on my HM170C0 set.
Regards,
Ramon |
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| RSQ8P |
Because Mark has not yet replied my e-mail regarding the matter.
Maybe on holiday? |
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