Hi, I recently purchased 2 Peerless 830946 6-1/2" mid-bass woofers. As the title says I am seeking advice on building a proper enclosure. -They are going into my work van and I was thinking about a custom mount behind my driver's seat (above my 10" JL sub)..separate them by about 20"..and run them in stereo
When I searched for other projects using these I found:
Peerless SLS 6.5" (830946) project - diyAudio
and
Peerless SLS 6.5 (830946) box size
BUT, I remember reading somewhere that mid-woofers should not have a rectangular box..and that for mid-woofers it was important to reduce standing waves as much as possible..and so an asymmetrical box or even rounded back was recommended. Could someone please confirm or deny whether I should be building some sort of strange-shaped enclosure for these?? -I would happily build whatever may sound the best! -I will even turn your advice into a DIY thread with some juicy pictures
Also, it was mentioned that reducing the box volume increased the resonant frequency of the box?? The specs from Peerless call for just over 3 liters per woofer (sealed). Could someone explain what would be the sound difference or frequency response if I used 2.5 liters instead?
In the second link a person said this speaker "fell apart" above 250hz. I had originally thought to run these active witha 12db @100hz (or a little higher) high pass and 24db slope at 450hz low pass. Any advice on that also? -If not I suppose I will just have to test that out when my enclosures are finished.
Definitely would love some input! I have all of the tools/supplies to build any kind of custom enclosure for these..and want to get it done by the end of today! xD
Last question: when mounting..should I aim these towards my ears..or reverse (like subwoofers)??
Answers, thoughts, suggestions, questions???
THANKS!!
When I searched for other projects using these I found:
Peerless SLS 6.5" (830946) project - diyAudio
and
Peerless SLS 6.5 (830946) box size
BUT, I remember reading somewhere that mid-woofers should not have a rectangular box..and that for mid-woofers it was important to reduce standing waves as much as possible..and so an asymmetrical box or even rounded back was recommended. Could someone please confirm or deny whether I should be building some sort of strange-shaped enclosure for these?? -I would happily build whatever may sound the best! -I will even turn your advice into a DIY thread with some juicy pictures
Also, it was mentioned that reducing the box volume increased the resonant frequency of the box?? The specs from Peerless call for just over 3 liters per woofer (sealed). Could someone explain what would be the sound difference or frequency response if I used 2.5 liters instead?
In the second link a person said this speaker "fell apart" above 250hz. I had originally thought to run these active witha 12db @100hz (or a little higher) high pass and 24db slope at 450hz low pass. Any advice on that also? -If not I suppose I will just have to test that out when my enclosures are finished.
Definitely would love some input! I have all of the tools/supplies to build any kind of custom enclosure for these..and want to get it done by the end of today! xD
Last question: when mounting..should I aim these towards my ears..or reverse (like subwoofers)??
Answers, thoughts, suggestions, questions???
THANKS!!
I'm not quite sure how you want to use them, crossed over as mids or sub mid range. Ideally you want mid range frequencies pointing towards you. With subs there is no hard rule they can point towards you or away whatever sounds best in the sweet spot.
I should probably post pictures of my final product huh? 😀
Distance from center to center is 23".
30 degree angle.
Unknown angle I literally guessed at.
A splash of color on the back for fun..haha
I haven't finished figuring out exactly how I want to mount them in conjunction with my sub yet...but I know they will be sitting a little less than 2ft behind me..and elevated by about 1.5ft or so. Amazingly, I think I actually got the angles pretty close..for a proto-type at least..haha.
Distance from center to center is 23".
30 degree angle.
Unknown angle I literally guessed at.
A splash of color on the back for fun..haha
I haven't finished figuring out exactly how I want to mount them in conjunction with my sub yet...but I know they will be sitting a little less than 2ft behind me..and elevated by about 1.5ft or so. Amazingly, I think I actually got the angles pretty close..for a proto-type at least..haha.
A member on diymobile mentioned "-The critical voice frequency is from 300Hz to 3KHz so keeping a crossover point out of that range is a good thing so.....
-how 'bout try letting those midbass drivers work where they are happiest, 80Hz to 250Hz.
Keeping the path length differences as close as possible is a concern but I'd still try to get them more foreward. If you must keep them behind you and only 20" apart then low pass them around 250Hz"
-I personally tested these theories and found them VERY true. Even with low pass right at 300hz it seemed my audio imaging was thrown a wee bit off (due to voice frequencies coming from behind me). In the end I settled in at 200hz @12db for lowpass and 83hz @24db for highpass.
Lastly..I would recommend these speakers for anyone looking to add some serious mid-bass.
-how 'bout try letting those midbass drivers work where they are happiest, 80Hz to 250Hz.
Keeping the path length differences as close as possible is a concern but I'd still try to get them more foreward. If you must keep them behind you and only 20" apart then low pass them around 250Hz"
-I personally tested these theories and found them VERY true. Even with low pass right at 300hz it seemed my audio imaging was thrown a wee bit off (due to voice frequencies coming from behind me). In the end I settled in at 200hz @12db for lowpass and 83hz @24db for highpass.
Lastly..I would recommend these speakers for anyone looking to add some serious mid-bass.
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Flush mount the drivers because diffraction effects start to be an issue as you go higher and if you are mounting the midrange in the same box also round edges out.
"Flush mount"?? Huh? Is it not apparent in the pictures that the drivers are flush mounted? The angle is for putting the speakers almost perfectly on-axis for my listening position.
...since I originally intended to run these Peerless a bit higher in frequency, I had made my enclosures slightly larger than the recommended 2.5L and put the standard house-grade pink insulation in the corners (I assume that would carry the same effect of rounding the edges like you mentioned?)..my reasoning was to cancel an extra bit of the rear-wave while also hoping to reduce some of the vibrations emanating from the rear of the enclosure (because I have tools stored behind where I mounted these).
And..the other mids (regular mid-uppers) will go into their own separate enclosures with tweeters..I think I will be using the egg-shell carton stuff for rounding the corners in that enclosure..but was planning to do a bit more research first.
I ran across OPSODIS, which seems like an arrangement that would work out really well for my situation. I will investigate that and Aperiodic enclosures for the mids. 😀
Happy Holidays!!
I consider many Peerless drivers to be very competitive with the best there is. 6 inch drivers should be able to do 80HZ - 800HZ very well. The weak link will be the enclosure and acoustics of the inside of the van. If they will go above about 150HZ, you'll want nothing in the way - straight shot to your ears.
Any enclosure approximating a cube would be bad where the half wavelengths of the frequencies fit inside the internal dimensions (around 800HZ and up in this case). Since many woofers have fairly hard cones, the cones often have pretty severe mechanical resonance in the 4kHZ region (roughly), right where the ear is most sensitive, which many crossover filters don't attenuate enough, so physical padding of the inside of the enclosure is particularly important.
I'd use silicone rubber glues or Liquid Nails glue (or equiv.) to glue a fairly dense material like thick felt (at least 3/8 inch thick - more is better) to all the inside surfaces of the enclosure, and then glue foam rubber, maybe an inch thick, over that. Most of the so called acousically absorbtive fluffy stuff only works well at high frequencies (above 600HZ generally), plus if it's not glued in place it could flop up against the diaphram of the driver in some cases.
If the crossovers are accurate (passive xovers are usually very sloppy, since the impedance of the drivers vary significantly over frequency), the only frequency area I would bother to necessarily avoid having a crossover point would be 1.5kHZ - 6kHZ, but location of drivers relative to each other may be a much bigger issue. From 150HZ - 6kHZ, the drivers should be as close to each other as is practical.
Any enclosure approximating a cube would be bad where the half wavelengths of the frequencies fit inside the internal dimensions (around 800HZ and up in this case). Since many woofers have fairly hard cones, the cones often have pretty severe mechanical resonance in the 4kHZ region (roughly), right where the ear is most sensitive, which many crossover filters don't attenuate enough, so physical padding of the inside of the enclosure is particularly important.
I'd use silicone rubber glues or Liquid Nails glue (or equiv.) to glue a fairly dense material like thick felt (at least 3/8 inch thick - more is better) to all the inside surfaces of the enclosure, and then glue foam rubber, maybe an inch thick, over that. Most of the so called acousically absorbtive fluffy stuff only works well at high frequencies (above 600HZ generally), plus if it's not glued in place it could flop up against the diaphram of the driver in some cases.
If the crossovers are accurate (passive xovers are usually very sloppy, since the impedance of the drivers vary significantly over frequency), the only frequency area I would bother to necessarily avoid having a crossover point would be 1.5kHZ - 6kHZ, but location of drivers relative to each other may be a much bigger issue. From 150HZ - 6kHZ, the drivers should be as close to each other as is practical.
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Looks like flush mount to me. Have a dozen Peerless 6.5" here with similar truncated frames. Think the quilted fabric distorts depth.
What I meant to say is counter sink the driver so the baffle is flat with the frame of the driver. That little lip can cause secondary diffractions......However the material is what could be distorting the depth as mention by Greebster
OH! "Flush mount the driver", why didn't you say that? haha ;D Honestly, I'm not sure why I didn't make sense of that..sorry. The last translatation of counterskinking the driver hit the nail home (or screw)..haha.
I actually intended to countersink it..but failed to pickup a rabbeting bit before construction day. I have since then, been playing around with Bob Richard's advice..which will also affect the internal dimensions..so I'm going to do another build in a few weeks here after I do a few more calculations. At that point I will head the advice and flush mount the driver.
Thanks to all you genuine humans offering wisdom and advice, much appreciated! 😀
I actually intended to countersink it..but failed to pickup a rabbeting bit before construction day. I have since then, been playing around with Bob Richard's advice..which will also affect the internal dimensions..so I'm going to do another build in a few weeks here after I do a few more calculations. At that point I will head the advice and flush mount the driver.
Thanks to all you genuine humans offering wisdom and advice, much appreciated! 😀
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