Foam Core Board Speaker Enclosures? - Page 150

xrk971 · 06:59 PM

Jim,
That's great that you modeled it. You are right that the Met and FH3 are similar from standpoint of tapered MLTL - with FH3 having a horn-loaded assist on vent to direct to a wall or corner (should have more bass gain than Met). Can you share the results of you model? Did you use MJK? Speaking of Fonkens, I am designing a micro Onken for the TC9FD - can't truly get the "Onken" design criteria for this driver (and Dave D also noted that the uFonken w/ FF85WK isn't a true Onken either - but a high aspect ratio shelf vent bass reflex). I would like to build full size FH3 one of these days - but want to incorporate the curved rear horn that I developed in foam somehow in wood.
I am thinking of getting some thin plywood to cover the front baffle - maybe walnut or cherry veneer ply even... saw that at HD.
If you do post your sims and build progress for this, please put it in the FH3-inspired thread so that others can find it easier - there is so much in the FC thread that things can get lost.
Thanks,
X

xrk971 · 10th March 2013, 07:04 PM

Quote:

Originally Posted by xrk971

I modified my earlier folded TL stereo wall mount speaker to be a MLTL by adding a constrictor vent. The bass response is much better now...

Here is a sound clip from this speaker - I have been listening to it constantly in my office for the past couple of days. It sounds great with a variety of music including jazz, rock, R&B, hip-hop, pop, just about anything. Very balanced with great bass extension. I can just hear the low 41 Hz bass strings (soft) but at 50 Hz the levels are quite good.

KLBIrd · 11th March 2013, 11:47 AM

Most in room recordings that are tried in evaluating speakers have been poor. Especially those on Utube. Yours sounded like a remote broadcast from a club. All you needed were some background conversation and tinkling of glasses . The music sounded live and very real, demonstrating that you achieved the intended goal with your design . Great job!

xrk971 · 11th March 2013, 12:16 PM

Thanks Ken!

The tinkling glasses and background can be added by the user!

It actually sounds even better in real life than the recording - I guess that is why recording studios have nice $1000 mics and racks of equipment and anechoic wall liners...
I am doing something interesting with this speaker in that it is mounted directly behind me instead of in front as I do not have wall space in front. The sound is different from behind but the advantage is that it is closer (4 ft away) and I do not need to turn the volume up very high. I wish more folks would post sound clips of their speakers. I am not aware of anyone else in this forum who does. I think someone critiqued that posting it would be pointless because the effect of the room dominates and people really would not know what it sounds like. Yeah, but if it is good in your room, there is a chance that it might not be such a bad speaker. Better than buying(building) blind in any event.

KLBIrd · 11th March 2013, 12:42 PM

I have not tried that type of evaluation with projects but may do so, as I have one of those Zoom H4 digital recorders that I have used for recording live musical events. Certainly, all rooms all sound different and the amount of equalization applied can also make a difference. I believe in bass and treble controls. They are needed to balance the room environment and help the system reproduce the sound as required by the listener. Full range speakers in particular need some type of equalization to function properly.

xrk971 · 01:21 PM

We have the same recorder - nice units. You should post clips of your foam core speakers that you just built with the FR10's and the Audience A3's. Those TL's look really nice, would love to hear them.

Max file size for upload is 900kB and has to be in zip format as mp3 extension is not allowed.

KLBIrd · 11th March 2013, 07:41 PM

Both systems are back out in the shop but I will bring them back to the listening room in a day or two do some experimental recording.

KLBIrd · 12th March 2013, 04:10 PM

Ok, here is a recording with the H4. It was positioned at my usual listening spot , about 4 feet equally spaced. FR 10 was in the "Admiral Bull Horn" enclosure.

KLBIrd · 12th March 2013, 04:18 PM

Its no use, even ZIPed its too big for my DSL supplier. I am limited to 10mb per message.
Someday we will catch up with the rest of the world and have fiber optics to each subscriber.

xrk971 · 12th March 2013, 04:29 PM

Zipping doesn't compress mp3 any further (already compressed) - just needed to get around restriction of not allowing mp3 extension on uploaded attachments. The file size is your problem. DiyAudio only allows max file size of about 900 kB (0.9 MB) so your 10 MB limit should not be an issue. This means that at 128 kbps rate, the mp3 clip is about 30 seconds long. You can trim your mp3 file with software. A good free program to do this is Audacity. If you sampled at 320 kbps and you have a couple of minutes, it will be a big file. If you don't want to re-do the recording, open with Audacity and save as lower bitrate and trim length to fit. The zip. Then upload. I know, not the most user friendly or easy thing to do...

10th March 2013, 06:31 PM	#1491
xrk971 diyAudio Member Join Date: Oct 2012 Location: Virginia	Jim, That's great that you modeled it. You are right that the Met and FH3 are similar from standpoint of tapered MLTL - with FH3 having a horn-loaded assist on vent to direct to a wall or corner (should have more bass gain than Met). Can you share the results of you model? Did you use MJK? Speaking of Fonkens, I am designing a micro Onken for the TC9FD - can't truly get the "Onken" design criteria for this driver (and Dave D also noted that the uFonken w/ FF85WK isn't a true Onken either - but a high aspect ratio shelf vent bass reflex). I would like to build full size FH3 one of these days - but want to incorporate the curved rear horn that I developed in foam somehow in wood. I am thinking of getting some thin plywood to cover the front baffle - maybe walnut or cherry veneer ply even... saw that at HD. If you do post your sims and build progress for this, please put it in the FH3-inspired thread so that others can find it easier - there is so much in the FC thread that things can get lost. Thanks, X Last edited by xrk971; 10th March 2013 at 06:59 PM.

11th March 2013, 01:18 PM	#1496
xrk971 diyAudio Member Join Date: Oct 2012 Location: Virginia	We have the same recorder - nice units. You should post clips of your foam core speakers that you just built with the FR10's and the Audience A3's. Those TL's look really nice, would love to hear them. Max file size for upload is 900kB and has to be in zip format as mp3 extension is not allowed. Last edited by xrk971; 11th March 2013 at 01:21 PM.

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11th March 2013, 11:47 AM	#1493
KLBIrd diyAudio Member Join Date: Jan 2009 Location: Lincoln, Missouri	Most in room recordings that are tried in evaluating speakers have been poor. Especially those on Utube. Yours sounded like a remote broadcast from a club. All you needed were some background conversation and tinkling of glasses . The music sounded live and very real, demonstrating that you achieved the intended goal with your design . Great job!

11th March 2013, 12:16 PM	#1494
xrk971 diyAudio Member Join Date: Oct 2012 Location: Virginia	Thanks Ken! The tinkling glasses and background can be added by the user! It actually sounds even better in real life than the recording - I guess that is why recording studios have nice $1000 mics and racks of equipment and anechoic wall liners... I am doing something interesting with this speaker in that it is mounted directly behind me instead of in front as I do not have wall space in front. The sound is different from behind but the advantage is that it is closer (4 ft away) and I do not need to turn the volume up very high. I wish more folks would post sound clips of their speakers. I am not aware of anyone else in this forum who does. I think someone critiqued that posting it would be pointless because the effect of the room dominates and people really would not know what it sounds like. Yeah, but if it is good in your room, there is a chance that it might not be such a bad speaker. Better than buying(building) blind in any event.

11th March 2013, 12:42 PM	#1495
KLBIrd diyAudio Member Join Date: Jan 2009 Location: Lincoln, Missouri	I have not tried that type of evaluation with projects but may do so, as I have one of those Zoom H4 digital recorders that I have used for recording live musical events. Certainly, all rooms all sound different and the amount of equalization applied can also make a difference. I believe in bass and treble controls. They are needed to balance the room environment and help the system reproduce the sound as required by the listener. Full range speakers in particular need some type of equalization to function properly.

11th March 2013, 07:41 PM	#1497
KLBIrd diyAudio Member Join Date: Jan 2009 Location: Lincoln, Missouri	Both systems are back out in the shop but I will bring them back to the listening room in a day or two do some experimental recording.

12th March 2013, 04:10 PM	#1498
KLBIrd diyAudio Member Join Date: Jan 2009 Location: Lincoln, Missouri	Ok, here is a recording with the H4. It was positioned at my usual listening spot , about 4 feet equally spaced. FR 10 was in the "Admiral Bull Horn" enclosure.

12th March 2013, 04:18 PM	#1499
KLBIrd diyAudio Member Join Date: Jan 2009 Location: Lincoln, Missouri	Its no use, even ZIPed its too big for my DSL supplier. I am limited to 10mb per message. Someday we will catch up with the rest of the world and have fiber optics to each subscriber.

12th March 2013, 04:29 PM	#1500
xrk971 diyAudio Member Join Date: Oct 2012 Location: Virginia	Zipping doesn't compress mp3 any further (already compressed) - just needed to get around restriction of not allowing mp3 extension on uploaded attachments. The file size is your problem. DiyAudio only allows max file size of about 900 kB (0.9 MB) so your 10 MB limit should not be an issue. This means that at 128 kbps rate, the mp3 clip is about 30 seconds long. You can trim your mp3 file with software. A good free program to do this is Audacity. If you sampled at 320 kbps and you have a couple of minutes, it will be a big file. If you don't want to re-do the recording, open with Audacity and save as lower bitrate and trim length to fit. The zip. Then upload. I know, not the most user friendly or easy thing to do...