Did you add any additional bracing... out of the box these are not great performers.
dave
Hi Bill,
I am planning a 4+4.
How did you wire the 4+4? Did you damp the cabinet with sheep wool? Did you do the same like Audience (Bipol)?
Thanks for your answer.
Josef
I am planning a 4+4.
How did you wire the 4+4? Did you damp the cabinet with sheep wool? Did you do the same like Audience (Bipol)?
Thanks for your answer.
Josef
Dave,
I assume your statement about the Dayton 1/2 cu ft rectangular cabinet resonance/bracing is based on personal experience of tapping the sides of the cabinet (the resulting sound is not 'dead'). Yes, I noticed that the cabinet does have a relatively high frequency resonanance when tapped. If you have actual accelerometer-measurement spectral resonance data I would be interested.
The Dayton cabinet does have interior bracing, and I feel that attempting to add more bracing would not only be difficult, but would offer only diminishing returns. The front baffle of the Dayton cabinets is 1" MDF - so I think the top and sides are the culprits.
So, I'm leaning toward something like the borosilicate coating for deadening, like that used in VMPS speakers (interior coating said to be especially good for attenuating speech frequencies).
I've should have an old can of 'Acousti-coat' somewhere, which I understand has "ceramic microspheres and several special, trade secret, pigment particles" for sound deadening.
Last time I used this stuff, it did seem to deaden speaker cabinet wall resonances - especially the higher frequencies - which seems to be the case for these Dayton enclosures - so I believe.
In addition, might be adding exterior surface material on cabinets (like some of the high-end Italian speakers, etc.), to widen & round cabinet edges to help with BSC, as well as attenuating audible cabinet resonance.
Bill
I assume your statement about the Dayton 1/2 cu ft rectangular cabinet resonance/bracing is based on personal experience of tapping the sides of the cabinet (the resulting sound is not 'dead'). Yes, I noticed that the cabinet does have a relatively high frequency resonanance when tapped. If you have actual accelerometer-measurement spectral resonance data I would be interested.
The Dayton cabinet does have interior bracing, and I feel that attempting to add more bracing would not only be difficult, but would offer only diminishing returns. The front baffle of the Dayton cabinets is 1" MDF - so I think the top and sides are the culprits.
So, I'm leaning toward something like the borosilicate coating for deadening, like that used in VMPS speakers (interior coating said to be especially good for attenuating speech frequencies).
I've should have an old can of 'Acousti-coat' somewhere, which I understand has "ceramic microspheres and several special, trade secret, pigment particles" for sound deadening.
Last time I used this stuff, it did seem to deaden speaker cabinet wall resonances - especially the higher frequencies - which seems to be the case for these Dayton enclosures - so I believe.
In addition, might be adding exterior surface material on cabinets (like some of the high-end Italian speakers, etc.), to widen & round cabinet edges to help with BSC, as well as attenuating audible cabinet resonance.
Bill
Josef,
Using 16-ohm A3 drivers, wire front four in parallel = 4 ohms. Do the same for the four rear-facing drivers = 4 ohms. Then, connect front & rear drivers in series for a resulting 8-ohm load.
The Audience Clairaudient 4+4 speaker uses a custom, superior CNC-machined 15" wide, curved cabinet. You can visit Audience's website for details.
For cost reasons, I'm resorting to using much 'cheaper' 1/2 cu ft Dayton rectngular cabinets intended for the hobbyist. Anyway, idea is to mount 4 A3s on the front baffle & the other four drivers on the back of the cabinet.
Please note that a 1/2 cu ft enclosure is admittedly small for eight A3 drivers, but can't use a bigger cabinet because of room space limitations and WAF. This small cabinet volume is a compromise that I feel can be worked around. I going with a DIY quasi-aperiodic loading, and TBD electronic ckt for added freq contouring -- and using a good subwoofer to cover above say 70 Hz -- in any case, details are TBD.
As a mere hobbyist, my design approach is to be considered experimental.
As for specific TBD dampening materials, will use both fiberglass (reference is made to old Speaker Builder magazine articles) and some wool -- maybe even some 'black hole 5' now sitting on the shelf.
Maybe say more later,
Bill
Using 16-ohm A3 drivers, wire front four in parallel = 4 ohms. Do the same for the four rear-facing drivers = 4 ohms. Then, connect front & rear drivers in series for a resulting 8-ohm load.
The Audience Clairaudient 4+4 speaker uses a custom, superior CNC-machined 15" wide, curved cabinet. You can visit Audience's website for details.
For cost reasons, I'm resorting to using much 'cheaper' 1/2 cu ft Dayton rectngular cabinets intended for the hobbyist. Anyway, idea is to mount 4 A3s on the front baffle & the other four drivers on the back of the cabinet.
Please note that a 1/2 cu ft enclosure is admittedly small for eight A3 drivers, but can't use a bigger cabinet because of room space limitations and WAF. This small cabinet volume is a compromise that I feel can be worked around. I going with a DIY quasi-aperiodic loading, and TBD electronic ckt for added freq contouring -- and using a good subwoofer to cover above say 70 Hz -- in any case, details are TBD.
As a mere hobbyist, my design approach is to be considered experimental.
As for specific TBD dampening materials, will use both fiberglass (reference is made to old Speaker Builder magazine articles) and some wool -- maybe even some 'black hole 5' now sitting on the shelf.
Maybe say more later,
Bill
Yes, personal experience. From examining the cabinet to hearing what it did to the sonics of a set of FR125s vrs a very similar cabinet built from scratch to much higher standards.
It would oribably be best to just start from scratch... seems a shame that, having spent some 2400 bucks on drivers you'd compromise their performance by using a cheap cabinet, i expect you are not getting anywhere near the A3's potential.
The curved wall PE cab is a whole lot better but not up to what we build from scratch (not really close at all).
dave
Still optimistic
I remain optimistic that a combination of DIY cabinet dampening materials may work out.
The 2400 bucks has not been wasted.
These A3 drivers certainly can be used for other DIY speaker designs -- if the Dayton cabinets just can't be made to sound OK with added internal coatings and external dampening material(s) - the final cabinet appearance may not be as good as original naked cabinets, but still OK.
Quasi aperiodic loading is expected to reduce back-pressure on drivers and the cabinet walls - less resonance excitation.
Rectangular cabinet was chosen over curved because have to mount four drivers on the back of the cabinet. BTW, I have a pair of the 1 cu ft curved Dayton cabinets originally used for array of four A3 drivers, but feel that they are just too big to fit in allotted room space, and size is a WAF consideration.
Optimism: My Monitor Audio 'Silver S1' cabinets have even a worse audible resonance when tapped - yet these speakers still manage to sound good.
Also, VMPS seems to get results with borosilicate coating on MDF.
Yes, there are superior enclosures.
Before getting the Dayton cabinets, I did pursue better alternatives including something like the nice Audience 15" wide, closed, curved cabinets - now made using {expensive} & laborious CNC machining, etc.
Also initially considered an open-baffle configuration but the physical size is a problem -- if all else fails, may go back and pursue a better cabinet/more heroic bracing and so forth.
For an OB, could use light weight constrained-layer materials (ref 1998 Audio Express article on 'student' OB)
My woodworking skills and equipment are marginal compared to others in this forum.
So the Dayton cabinets are a compromise --
If my DIY concept shows strong promise, maybe next year will spend the big bucks to hire a local skilled woodworker to make really good cabinets -- by then should have a better ideas how to improve cabinet width/shape, suppress resonances, improve BSC, and so forth.
Maybe in a year or two, would like to try/evaluate adding a RAAL ribbon in at say 6 or 7 kHz using some kind of optimum (coherent) group-delay ckt -- dare I say, 'crossover'. Adding a RAAL might not be so ridiculous with A3s, considering Vance Dickason in his recent VC mag review, suggested a 6kHz crossover if a tweeter were to be used with A3s.
BTW, the January 2002 and February 2002 issues of "Audio Express" had a great article about using layers of fiberglass in open-back enclosures ("The Infinite Box Concept") for enhanced bass response & rear-wave reduction, etc. The Feb 02 issue also had interesting 'panel dampening studies'.
Bill
I remain optimistic that a combination of DIY cabinet dampening materials may work out.
The 2400 bucks has not been wasted.
These A3 drivers certainly can be used for other DIY speaker designs -- if the Dayton cabinets just can't be made to sound OK with added internal coatings and external dampening material(s) - the final cabinet appearance may not be as good as original naked cabinets, but still OK.
Quasi aperiodic loading is expected to reduce back-pressure on drivers and the cabinet walls - less resonance excitation.
Rectangular cabinet was chosen over curved because have to mount four drivers on the back of the cabinet. BTW, I have a pair of the 1 cu ft curved Dayton cabinets originally used for array of four A3 drivers, but feel that they are just too big to fit in allotted room space, and size is a WAF consideration.
Optimism: My Monitor Audio 'Silver S1' cabinets have even a worse audible resonance when tapped - yet these speakers still manage to sound good.
Also, VMPS seems to get results with borosilicate coating on MDF.
Yes, there are superior enclosures.
Before getting the Dayton cabinets, I did pursue better alternatives including something like the nice Audience 15" wide, closed, curved cabinets - now made using {expensive} & laborious CNC machining, etc.
Also initially considered an open-baffle configuration but the physical size is a problem -- if all else fails, may go back and pursue a better cabinet/more heroic bracing and so forth.
For an OB, could use light weight constrained-layer materials (ref 1998 Audio Express article on 'student' OB)
My woodworking skills and equipment are marginal compared to others in this forum.
So the Dayton cabinets are a compromise --
If my DIY concept shows strong promise, maybe next year will spend the big bucks to hire a local skilled woodworker to make really good cabinets -- by then should have a better ideas how to improve cabinet width/shape, suppress resonances, improve BSC, and so forth.
Maybe in a year or two, would like to try/evaluate adding a RAAL ribbon in at say 6 or 7 kHz using some kind of optimum (coherent) group-delay ckt -- dare I say, 'crossover'. Adding a RAAL might not be so ridiculous with A3s, considering Vance Dickason in his recent VC mag review, suggested a 6kHz crossover if a tweeter were to be used with A3s.
BTW, the January 2002 and February 2002 issues of "Audio Express" had a great article about using layers of fiberglass in open-back enclosures ("The Infinite Box Concept") for enhanced bass response & rear-wave reduction, etc. The Feb 02 issue also had interesting 'panel dampening studies'.
Bill
Aside from incongruity between the cost of the A3 and PE box, you are not going to get the maximum potential out your drivers with the PE box. Unfortunately, all boxes resonate, but designers will use this resonance to be "friendly" in the overall frequency response. That is, your Monitor Audio speakers box resonance has probably been accounted for in the overall design. I have heard the 4+4 Audience speaker and it sounds really really good, regardless of the rear array position (which also may play a role since the speakers sound best when physically crossed in front of the listening position). The Audience box has a wide baffle and rounded edges which probably account for less bsc and diffraction.
I recall, though it has been a while and my memory has faded, that the Audience box was triangular/3 sided if viewed from the top. Thus, the rear array must not have been directly behind the front array. Perhaps, this was a design decision or the result serendipitous. Either way the speaker sounded great when positioned so that the drivers crossed in front of the listening position. Again, box design is part of the speaker design and this particular box had a wide baffle and rounded edges.
Dayton cabinets (damped) are only a first try.
Agree that stock Dayton 1/2 cu ft rectangular cabinets are not the best -- but it remains to be seen whether or not planed modifications will be acceptable.
In any case, the A3 drivers can be used in other experimental "4+4" array configurations/cabinets.
I have backup ideas if these Dayton cabinets can't be made to sound good by using interior sound deadening materials and/or additional outside coverings for acoustic edge-rounding (help BSC) & resonance reduction.
The previously mentioned January 2002 and February 2002 issues of "Audio Express" presented concept of using layers of fiberglass in open-back enclosures ("The Infinite Box Concept" = "IB"). This two-part IB article mentioned that even cardboard with bonded dampening material might be used to make what I would call a "poor-man's enclosure" (open-back) - should be easy to make a nice wide curved front box out of damped cardboard, rug, foam exercise mat, etc.
Still optimistic.
Bill
Agree that stock Dayton 1/2 cu ft rectangular cabinets are not the best -- but it remains to be seen whether or not planed modifications will be acceptable.
In any case, the A3 drivers can be used in other experimental "4+4" array configurations/cabinets.
I have backup ideas if these Dayton cabinets can't be made to sound good by using interior sound deadening materials and/or additional outside coverings for acoustic edge-rounding (help BSC) & resonance reduction.
The previously mentioned January 2002 and February 2002 issues of "Audio Express" presented concept of using layers of fiberglass in open-back enclosures ("The Infinite Box Concept" = "IB"). This two-part IB article mentioned that even cardboard with bonded dampening material might be used to make what I would call a "poor-man's enclosure" (open-back) - should be easy to make a nice wide curved front box out of damped cardboard, rug, foam exercise mat, etc.
Still optimistic.
Bill
help with tuning A3 1 + 1 Cabinet?
I am reviving this thread because of the following:
I am building two pair of single driver full range speakers with the A3. One set will be in small closed boxes (about 1 liter) to be used with a subwoofer. The other one will be in a slightly bigger box with a passive radiator. On first listen experiments, I was disappointed with the high-mid to high response of the drivers in both boxes. It sounds harsh, and a bit unpleasant. My reference track is Marlene on the wall by Suzanne Vega. In this track the vocal (especially the "t" and "s" and reverb tales) are really "fighting" with the acoustic rhythm guitar. Could this be the not finished enclosures (no rounded edges, no sunk in driver, passive radiator in the side), or is something else going on? Would like to hear your input!
I am reviving this thread because of the following:
I am building two pair of single driver full range speakers with the A3. One set will be in small closed boxes (about 1 liter) to be used with a subwoofer. The other one will be in a slightly bigger box with a passive radiator. On first listen experiments, I was disappointed with the high-mid to high response of the drivers in both boxes. It sounds harsh, and a bit unpleasant. My reference track is Marlene on the wall by Suzanne Vega. In this track the vocal (especially the "t" and "s" and reverb tales) are really "fighting" with the acoustic rhythm guitar. Could this be the not finished enclosures (no rounded edges, no sunk in driver, passive radiator in the side), or is something else going on? Would like to hear your input!
A3 box size?
I sold out my website last year and don't have my files handy due to a divorce and move. Most everything is still in boxes.
From what I remember, you may need 1 to 1.5 liters per driver. If this is the case, it could be your problem.
At this time, I would like to refer you to Roger Sheker the engineer at Audience. His reply could save you countless hours of rebuilding and frustration with your build. His email address can be found by visiting Audience-Av.com.
I sent Audience a case of passive radiators to experiment with due to the low Q of the A3 driver, and it became such a compliment to their drivers that they had a spec passive built for their newest production line of loudspeakers, critical to a single gram.
I wish you the best with your builds.
Mike
I sold out my website last year and don't have my files handy due to a divorce and move. Most everything is still in boxes.
From what I remember, you may need 1 to 1.5 liters per driver. If this is the case, it could be your problem.
At this time, I would like to refer you to Roger Sheker the engineer at Audience. His reply could save you countless hours of rebuilding and frustration with your build. His email address can be found by visiting Audience-Av.com.
I sent Audience a case of passive radiators to experiment with due to the low Q of the A3 driver, and it became such a compliment to their drivers that they had a spec passive built for their newest production line of loudspeakers, critical to a single gram.
I wish you the best with your builds.
Mike
Eric,
I've build several speakers with these drivers: one single and another one double with a supertweeter. First af all, you need a slightly larger box. I'd say 2.2 liters for ported (passive radiator) and even larger for closed. The later is because I prefer the low-Q alignment.
Second, and most relevant, there is quite large peak in the response of this driver, centerd around 8kHz and good 8dB high. I've designed a series LCR filter for the 16 Ohm version of the driver. If this is the way you use it - let me know and I'll send you the values. I don't have them handy right now - need to dig at home.
Third, if your baffle width is close to mine (4.5-5"), there is a "baffle step": a rize in response by about 6 dB from about 400Hz to about 1200 Hz, according to my measurements. I've used a second series circuit to compensate for it. Again, if you use a 16 Ohm implementation of the driver, connect 1.8mH coil and 12 Ohm resistor in parallel and this whole thing in series with the driver.
If you use newer doual-coil drivers and you connected them in 4 Ohm configuration, the values will have to be re-calculated.
Hope this helps,
VadimB
I've build several speakers with these drivers: one single and another one double with a supertweeter. First af all, you need a slightly larger box. I'd say 2.2 liters for ported (passive radiator) and even larger for closed. The later is because I prefer the low-Q alignment.
Second, and most relevant, there is quite large peak in the response of this driver, centerd around 8kHz and good 8dB high. I've designed a series LCR filter for the 16 Ohm version of the driver. If this is the way you use it - let me know and I'll send you the values. I don't have them handy right now - need to dig at home.
Third, if your baffle width is close to mine (4.5-5"), there is a "baffle step": a rize in response by about 6 dB from about 400Hz to about 1200 Hz, according to my measurements. I've used a second series circuit to compensate for it. Again, if you use a 16 Ohm implementation of the driver, connect 1.8mH coil and 12 Ohm resistor in parallel and this whole thing in series with the driver.
If you use newer doual-coil drivers and you connected them in 4 Ohm configuration, the values will have to be re-calculated.
Hope this helps,
VadimB
@Mike: thank you... I think I need a bit larger volume though, judging from the dimensions of The ONE from Audience: Audience ONE nearfield loudspeaker
@Vamid: Thank you as well! I am definitely interested in the circuit schematics. Do you think Audience is using something like you designed in their The ONE speaker as well?... I have no clue however if I have the older or newer ones.. how can you tell?
Basically , I am building two pairs: one with the 2.2 liters you suggest with a passive radiator as full rangers. The other ones will be with an added subwoofer. From my research I have found that using a passive radiator with a subwoofer is not a very good idea, that is why the closed enclosure. Would you still prefer a 3 liter box if used with a subwoofer?
@Vamid: Thank you as well! I am definitely interested in the circuit schematics. Do you think Audience is using something like you designed in their The ONE speaker as well?... I have no clue however if I have the older or newer ones.. how can you tell?
Basically , I am building two pairs: one with the 2.2 liters you suggest with a passive radiator as full rangers. The other ones will be with an added subwoofer. From my research I have found that using a passive radiator with a subwoofer is not a very good idea, that is why the closed enclosure. Would you still prefer a 3 liter box if used with a subwoofer?
1. I don't know what they are using, but if this peak is not taken care of, it's very audible. Gives a bit of nasal sound to brass and even vocals. It actually rings at 8.2 kHz.
2. If your driver has only one pair of trminals, then it's an older, single coil driver and it is 16 Ohm impedance. If it has 2 pairs of trminals, it's a newer dual voice coil driver. Each coil is 8 Ohm. You have an option to connect them in series (- of the first to + of the second) and obtain an equivalent of the older 16 ohm driver, or you may connect them in parallel (+ to +; - to -) and end up with a 4 Ohm driver. Let me know which one you have and if it's the second one, we will talk about advantagies and negatives of each.
3. The issue with the sub is the XO frequency. If you look at the pictures on my web site, I use a pair of woofers, not subs, crossed at 200 Hz. It can go lower, but the issue is power handling. The lower the XO, the less power you can use on Audience and the lower Max SPL you can get. If you are making close-range monitors, say for PC use, no subwoofers and needed in my opinion.
Take a look at the attached file. These are WinISD similations, but with actually measured driver parameters. The left is ported in 2.2 l, the right is closed in 3.3 L. This closed box results in Q=0.5, which is critically damped and my preference as of late. If you use the XO on the sub only and not on satelites, then you would need 2nd order XO at about 130-140 Hz for the closed box, and a 4th order XO at about 65 Hz for the ported (or passive rad) box.
You need to take care of the 8kHz peak regrdless of what box you use.
Vadim
2. If your driver has only one pair of trminals, then it's an older, single coil driver and it is 16 Ohm impedance. If it has 2 pairs of trminals, it's a newer dual voice coil driver. Each coil is 8 Ohm. You have an option to connect them in series (- of the first to + of the second) and obtain an equivalent of the older 16 ohm driver, or you may connect them in parallel (+ to +; - to -) and end up with a 4 Ohm driver. Let me know which one you have and if it's the second one, we will talk about advantagies and negatives of each.
3. The issue with the sub is the XO frequency. If you look at the pictures on my web site, I use a pair of woofers, not subs, crossed at 200 Hz. It can go lower, but the issue is power handling. The lower the XO, the less power you can use on Audience and the lower Max SPL you can get. If you are making close-range monitors, say for PC use, no subwoofers and needed in my opinion.
Take a look at the attached file. These are WinISD similations, but with actually measured driver parameters. The left is ported in 2.2 l, the right is closed in 3.3 L. This closed box results in Q=0.5, which is critically damped and my preference as of late. If you use the XO on the sub only and not on satelites, then you would need 2nd order XO at about 130-140 Hz for the closed box, and a 4th order XO at about 65 Hz for the ported (or passive rad) box.
You need to take care of the 8kHz peak regrdless of what box you use.
Vadim
Attachments
Vadim (and not Vamid, sorry). Thanks again for your help. I have to study a bit on the whole subwoofer thing, but let's focus on building the best passive radiator, full rangers first. I have the newer model with two connectors. However, when I measure between the + and - of each connector, it reads 6 Ohm!.
6 Ohm sounds about right, because it is a DC resistance. The full impedance at some higher frequencies will be higher, so it nominally is an 8 Ohm coil. The old 16 Ohm drivers had DCR of 12.8 Ohm.
Do you have a particular Passive radiator in mind? Do you know the parameters? I may be able to simulate the speaker for you. Just out of curiocity: why a passive radiator and not a port?
Vadim
Do you have a particular Passive radiator in mind? Do you know the parameters? I may be able to simulate the speaker for you. Just out of curiocity: why a passive radiator and not a port?
Vadim
Port..
Vladim,
When I was a distributor for Audience I built some ported cabinets and found that that the drivers unload too quickly because of the lack of internal cabinet pressure and you lose precious dbs and they can reach xmax too quickly. We decided not to recommend the ported designs anymore.
Just my .02
Mike
Vladim,
When I was a distributor for Audience I built some ported cabinets and found that that the drivers unload too quickly because of the lack of internal cabinet pressure and you lose precious dbs and they can reach xmax too quickly. We decided not to recommend the ported designs anymore.
Just my .02
Mike
Attachments
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This passive radiator: http://www.parts-express.com/pedocs/specs/264-1060-peerless.Basically because it was recommended. But also because a ported version would be to noisy... Tnx for looking into it!
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