Using subwoofer with cover on?

[revyth]

I have recently got a Yamaha DXS18XLF + cover (https://www.thomann.de/it/yamaha_spcvr_dxs18x.htm). The cover can be open on the front, as shown in the image so in teory it can remain on the speaker during operation.

I have no experience so asking for advice: is it a good or a bad idea to use the speaker with the cover on? Will it impact the sound or the heat dissipation?

[ef37a]

I cannot readily find a picture of that sub showing its heatsink but I would think it a very bad idea to run it in that cover.
Yamaha being top kit and clever people I suspect that all that would happen is the PSU would shut down but you never know, could be smoke!

Why would you want to do this pray?

Dave.

[shufflebeat]

That doesn’t look like a branded Yamaha cover, which is designed with lots of zipped and velcro’d flaps to accommodate airflow so I think we can say with confidence - don’t use it.

[Wonks]

I’d imagine the heatsink is inside the sub and relies on the driver moving the air to cool it. The cover will restrict some of that air movement in and out of the bass ports, so I’d avoid using it at anything like full volume. And with the amount of holes and gaps in the cover, I wouldn’t want to rely on it to keep water out.

So it really would be best to take the cover off.

[revyth]

Thank you guys for your answers. I had never thought about using the subwoofer with a cover, but after reading in the cover’s specifications that it could be left on during use, I started having doubts. Thank you for confirming that it’s a bad idea.

[shufflebeat]

One thing I’ve done with my baby EVs is to make a rain (beer) cover of heavy black plastic sheet which covers the top surface and overhangs the edge, folding down and sloping away to carry any stray drops out of reach of the speaker. A hole in the centre allows for fitting the m20 speaker pole which, along with the fold, holds all in place during battle.

When not in use the spray covers live inside the EV speaker covers as though they weren’t there.

I have several sets of Yamaha tops, DXR and DZR which work great with the (proper) covers on.

[revyth]

One thing I’ve done with my baby EVs is to make a rain (beer) cover of heavy black plastic sheet which covers the top surface and overhangs the edge, folding down and sloping away to carry any stray drops out of reach of the speaker. A hole in the centre allows for fitting the m20 speaker pole which, along with the fold, holds all in place during battle.

When not in use the spray covers live inside the EV speaker covers as though they weren’t there.

I have several sets of Yamaha tops, DXR and DZR which work great with the (proper) covers on.

Hi! Yes I am talking about the official Yamaha covers (for DXS18XLF and DZR). So is it safe to leave them on even for "intensive" use?

[AlecSp]

Rather than all the conclusions people have made based on a single, not very helpful picture, you might get a more reliable response from the manufacturer, which is only 5 secs googling away

https://www.yamahamusiclondon.com/SPCVR ... PCVRDXS18X

Yes, they recommend that you can use it with the cover on. (Hopefully) Obviously, make sure you've opened any of the flaps designed for that purpose, and reme,ber that it's not waterproof.

[shufflebeat]

Yes, they recommend that you can use it with the cover on.

If it’s the properly designed Yamaha variant, that is.

If not (no sign of a logo) then it’s a tea-cosy.

[AlecSp]

If it’s the properly designed Yamaha variant, that is.

If not (no sign of a logo) then it’s a tea-cosy.

The OP did reference the SPCVR-DXS18X so yes.

[shufflebeat]

If it’s the properly designed Yamaha variant, that is.

If not (no sign of a logo) then it’s a tea-cosy.

The OP did reference the SPCVR-DXS18X so yes.

…and then provided a picture which didn’t seem to correspond with the cover mentioned.
Getting this wrong might cost the OP a sub so best to clarify before being definitive.

[revyth]

Yes, it is the Yamaha one. Sorry for the confusion, I just took a picture with the front element removed to show what is underneath.
It seemed strange to me to use the cover on, so I wanted to be sure. But good to know it can be used without affecting performance

[Wonks]

It must affect the amount of air physically travelling through the reflex port(s). But whether that's enough to cause any issues at max power I have no idea. I'd suggest taking the cover off if used outside on hot days with a lot of sun, to be on the safe side.

[ef37a]

It must affect the amount of air physically travelling through the reflex port(s). But whether that's enough to cause any issues at max power I have no idea. I'd suggest taking the cover off if used outside on hot days with a lot of sun, to be on the safe side.

I agree but I would be more concerned about "insulating" the heat sink? As I understand sound theory there is little or no net exchange of air through a reflex port? After all, passive radiators work just as well and they are airtight.

Dave.

[Wonks]

There is no external heat sink, it's inside the cabinet. So any cooling of the internal heat sink is by the air movement inside the cabinet primarily from the speaker moving.

There is certainly air movement through the reflex port, but there is less movement at the resonant frequency where it puts up more resistance to airflow. Obviously the net exchange of air through the port is zero over time, otherwise you'd either end up with a massive internal pressure or an internal vacuum, both of which would cause the speaker cone to hardly move.

But air is pushed out, and as it does so it entrains some of the external air and mixes with it. So some of the external air is then pulled back in, as is some of the internal air. It's not a huge amount, but it's happening many times per second, and does help keep the internal temperature down.

Put a permeable cloth membrane over the front and there will be more resistance to air movement, especially at louder volumes where there's more air displacement through the port(s) and air resistance above a certain velocity is a square law proportional to velocity. The membrane itself will move backwards and forwards, transmitting the sound waves, but it will tend to keep a fair proportion of the internal air within the membrane, reducing mixing with external air.

[shufflebeat]

I was a bit sceptical about the price before picking up my Yamaha DXR12 covers but when they came up in a sale I bit the bullet. They are quite a feat of zip/Velcro engineering with a little bit of Origame in the design, certainly worth the discounted price to me and also worth the full asking price if I’d known.

The tough external cover folds back to expose some very open plan gauze, still quite strong but more of a grille than a sheet, very transparent and, I would assume, providing very little air-flow resistance.

Anything vital to the DXR12 fan cooling system is totally exposed when set up properly and any surface that remains “insulated” is not part of the cooling.

If the same design care has been applied to the sub cover then I’m pretty sure you’ll have no problem. If anyone else has had an issue it will be all over the internet, I’ve not seen anything of concern in my casual conversations.

[Hugh Robjohns]

The cover appears to have removable/openable panels for the front and rear, so I'd recommend removing or opening them to maximise airflow when in use. There are slots on the rear panel for airflow and you shouldn't block them off. It looks like the rear panel acts as a heatsink to some extent — a so-called 'plate amplifier' design which is common for Class-D amps these days.

And if you plan to stack other things directly on top of the sub I'd remove the cover as it might affect stability...

But clearly, padded covers on the sides and top aren't going to affect the ventilation or sound.

[shufflebeat]

And if you plan to stack other things directly on top of the sub I'd remove the cover as it might affect stability...

That looks like a flap-cover for an M20 speaker pole fitting as well so they’re facilitating normal use with a top, er… on top.

[edit]
Ooh, two speaker pole fittings - posh!

[ef37a]

I was a bit sceptical about the price before picking up my Yamaha DXR12 covers but when they came up in a sale I bit the bullet. They are quite a feat of zip/Velcro engineering with a little bit of Origame in the design, certainly worth the discounted price to me and also worth the full asking price if I’d known.

The tough external cover folds back to expose some very open plan gauze, still quite strong but more of a grille than a sheet, very transparent and, I would assume, providing very little air-flow resistance.

Anything vital to the DXR12 fan cooling system is totally exposed when set up properly and any surface that remains “insulated” is not part of the cooling.

If the same design care has been applied to the sub cover then I’m pretty sure you’ll have no problem. If anyone else has had an issue it will be all over the internet, I’ve not seen anything of concern in my casual conversations.

Oh! So it has a fan...nuff said!

Dave.

[Hugh Robjohns]

The DXR12 that Shuffle is talking about is a top cab, not the subwoofer in question....

...But yes, the DXS18XLF does have a variable speed cooling fan, as listed in the specs here:

https://www.yamahamusiclondon.com/DXS18 ... DXS18XLFUK

[shufflebeat]

Oh! So it has a fan...nuff said!

Dave.

Yes, I suppose I am.

Oh, I see what you mean.

[Wonks]

Yes indeed. I was rather led astray by the Thomann pictures of the cover which failed to show the actual rear panel and I thought that one of the other pictures was the rear.

Even the Yamaha page only shows the rear of the cover in a smaller insert picture rather than a clear full-sized picture.

They really aren’t very good at selling the product to you, given that most people will buy on line.