I fear that I may have created a problem for myself 🙂
I'm building a speaker using a BMS 12S305 (12", linear Xmax 11mm).
Using the formulas used by some manufacturers the calculated Xmax is around 14mm.
The design critieria, that has resulted in this choice is a compact, luggable cabinet and a decent output down to 40Hz (decent as in 110++ dB)
Given my need for transporting the speaker around I really need to have some kind of grille in front of the speaker to protect against physical damage.
Usually I use the standard round grilles that fits just over the speaker, but on examination it looks as if the membrane will hit the grille when pushing the speaker near its maximum extension.
I am not fan of the speaker wide nets (they seem to flimpsy to provide any real protection).
So: are there other options for protecting the membrane from physical harm or does anyone know of a method to provide more space between the membrane and the grille?
Regards
Martin
PS: This may not be the correct forum, but I guess it is here most experience with high Xmax-speakers is found
I'm building a speaker using a BMS 12S305 (12", linear Xmax 11mm).
Using the formulas used by some manufacturers the calculated Xmax is around 14mm.
The design critieria, that has resulted in this choice is a compact, luggable cabinet and a decent output down to 40Hz (decent as in 110++ dB)
Given my need for transporting the speaker around I really need to have some kind of grille in front of the speaker to protect against physical damage.
Usually I use the standard round grilles that fits just over the speaker, but on examination it looks as if the membrane will hit the grille when pushing the speaker near its maximum extension.
I am not fan of the speaker wide nets (they seem to flimpsy to provide any real protection).
So: are there other options for protecting the membrane from physical harm or does anyone know of a method to provide more space between the membrane and the grille?
Regards
Martin
PS: This may not be the correct forum, but I guess it is here most experience with high Xmax-speakers is found
Why not set the baffle back from the cabinet front and use a full metal grille mounted on circumferential battens?
Expanded steel mesh speaker grille material is available in 1250mm square sheets from this UK supplier for example: Speaker grilles | The Expanded Metal Company
Expanded steel mesh speaker grille material is available in 1250mm square sheets from this UK supplier for example: Speaker grilles | The Expanded Metal Company
Thank you, Galu
That is exactly the type of "speaker wide net" that I find a little bit too flimpsy.
But maybe I should give it a go anyway.
Next problem will be to find it somewhere nearby (sending a sheet of material more that a square meter in size will likely be very expensive).
I have just mailed The expanded Metal Company to ask.
Best regards
Martin
That is exactly the type of "speaker wide net" that I find a little bit too flimpsy.
But maybe I should give it a go anyway.
Next problem will be to find it somewhere nearby (sending a sheet of material more that a square meter in size will likely be very expensive).
I have just mailed The expanded Metal Company to ask.
Best regards
Martin
I just use round speaker "metal grill", one per speaker and havent had any accidents in 40+ years.
Usually the speaker cone doesn't extend past the gasket height.
You can recess the speaker into the baffle if wood thickness allows, or make a round thingy to put around the speaker and attach the grille into it.
Small door stoppers or wood block under the grille screw holes comes to me in mind.
The ones You buy at hardware stores are usually flimsy, but I've seen stiffer ones also.
I've been happy with using these square grilles for my speakers.
They also have all the hardware needed for speakers / racks.
TakeSound | Grilles / Clamps
I thought they were from Penn Elcom, as they are distributors, but today I can't see them on the website. Could be other manufacturer.
You can also mount the round protective grills on risers.
You make such risers easily using thick walled tube and a hacksaw. I've a couple of old Tandy/RadioShack grills and they are anything but flimsy
You make such risers easily using thick walled tube and a hacksaw. I've a couple of old Tandy/RadioShack grills and they are anything but flimsy
I hate grills so my solution to this is to recess the speaker in its own small front chamber and use a wooden driver cover with a gaps at the top and bottom. It does not effect the response until 100hz+ where it starts increasing effeciency.
I am with you on this when talking about "normal" speakers - but with this particular speaker with its Xmax of 11mm it will extend outside the gasket height.
Given that I have not yet identified a local supplier I will probably opt for the "round thingy" (this is where a router comes in as a very useful tool)
Cheers,
Martin
Thanks - I think that this solution would give me a lot of other problems (the speaker is not a sub-woofer, but actually a 2-way).
But this design would surely solve the Xmax problem.
Cheers,
Martin
Nothing beats testing and measuring (well, besides thinking or a good beer, possibly 🙂
I've just unpacked the newly arrived speaker and connected it to my small lab amplifier (~12W).
At very low frequencies the membrane extended far outside the gasket and when I just for eyeballing held the grille in front of the speaker, the membrane came uncomfortably close the grille.
And I haven't even tried to make the speaker extend to its maximum.
One observation to add: the folds of the membrane edge (sorry: forgot the proper name) are unusual deep - likely to support the high Xmax.
The fold connecting to the membrane edge extends some 4mm's over the membrane - this also adds to the total extension outside the gasket.
@tigeranand
I did make the speaker with the BMS driver.
It is not a sub though - it is the bass driver in a 2 way speaker for bass guitar.
I have been using it for more than 3 years now including several gigs in cafees (no PA, audience of around 50)
It works really well - and it delivers a sound that is not what you usually get from a normal bass rig (but in my opinion better 🙂 ).
One thing that I have noticed is that allthough the speaker is not particulary sensitive (95dB according to the datasheet and around 92dB with WinISD) I rarely exceed 30W to the speaker.
This leaves me with more than 10dB headroom.
This may be explained by that I do not need to EQ the bass up as is rather often needed with commercial bass rigs.
In case anyone should wonder about the 2 way: I XO at 500 Hz to a Beyma 6½" with phase plug.
I do this to increase the frequency where beaming starts to be annoying as much a reasonably possible.
Cheers, Martin
I did make the speaker with the BMS driver.
It is not a sub though - it is the bass driver in a 2 way speaker for bass guitar.
I have been using it for more than 3 years now including several gigs in cafees (no PA, audience of around 50)
It works really well - and it delivers a sound that is not what you usually get from a normal bass rig (but in my opinion better 🙂 ).
One thing that I have noticed is that allthough the speaker is not particulary sensitive (95dB according to the datasheet and around 92dB with WinISD) I rarely exceed 30W to the speaker.
This leaves me with more than 10dB headroom.
This may be explained by that I do not need to EQ the bass up as is rather often needed with commercial bass rigs.
In case anyone should wonder about the 2 way: I XO at 500 Hz to a Beyma 6½" with phase plug.
I do this to increase the frequency where beaming starts to be annoying as much a reasonably possible.
Cheers, Martin
I hate grills so my solution to this is to recess the speaker in its own small front chamber and use a wooden driver cover with a gaps at the top and bottom. It does not effect the response until 100hz+ where it starts increasing effeciency.
It's still a BP6P.
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