Are Sealed Cabs Better for Tube Amps?

[Count Bassie]

I have this old Peavey (DIY mod) 215 cab, loaded with BW 1502-8s. It's not reeeeeally tuned, and not ideal, but if I were to seal it's ports, would that smooth-over much of my tuning issue?

I'm going to use it, as it's all I really have for the next few months. I'm not gigging out, just doing rehearsals at home, so it's not going to be a major problem.

I'm playing my Peavey Dyna-Bass Unity through a Sunn 300T. I also have a Schroeder 1210R, and an Avatar 210 NEO. But I'd like to use the 215...

Thanks for your time!

 

[jz0h4d]

No... the tube amp couldn't care less.

 

[Nighttrain1127]

Not so tubes like the the cone control of a sealed Box. It is a known fact that tube amps can't keep control of a woofer When it gets going like a solid state amp can (damping is what it is actually called and tubes just don't have it in the low end).

 

[Count Bassie]

Not so tubes like the the cone control of a sealed Box. It is a known fact that tube amps can't keep control of a woofer When it gets going like a solid state amp can (damping is what it is actually called and tubes just don't have it in the low end).

This makes a certain amount of sense to my un-knowledgeable thinking- the SVT came with a sealed 8x10 cab...

So then, sealing my 215 makes sense, right? And it doesn't much matter how I do it- also right?

Thanks Steve. And thanks for offering, jz... (Only kidding, man!! )

 

[Psycho Bass Guy]

Sorry guys; it just ain't so. The difference in damping between tube and solid state amps is miniscule when there is a difference at all. A cab might sound better when sealed instead of ported if the drivers work better that way, but I'll repeat yet again: it is a MYTH that tube amps need a sealed cab or that there is ANY difference in performance with a tube amp and ANY kind of cab.

 

[perogato02]

The only thing I know about sealed - ported cabinets comes from the car-hifi world and I was told that it only mattered for the speakers (but they don't know tube amps there, do they?)... But hey, I could be wrong. But you could check on car hifi-sites to find out?

 

[Son of Bovril]

why does epifani not recommend using tube amps with their UL cabs I wonder?

 

[Psycho Bass Guy]

why does epifani not recommend using tube amps with their UL cabs I wonder?

...because speaker builders can believe myths, too.

 

[maccastarr]

I don't understand the question. Are you asking whether a tube amp needs a closed cab to work right, without harming the amp? If so, I'm pretty sure the answer is no -- look at all the guitar tube amps that are used with open-backed cabs.

If the question is whether it will sound better with a closed cab, then I think the answer is that depends on what sound you are after and the head you use. Open and closed cabs generally sound different from one another, and which one is right for you depends on what you are looking for. I think the tight projection and bottom end associated with closed back cabs is the reason there are so many closed bass cabs, and not any requirement that a tube head must be used with a closed cab.

Although there are so many closed bass cabs, it is interesting to note that McCartney is reported to have used an open backed 2x12 for a lot of those great mid-60's Beatles recordings.

 

[Toffa]

This makes a certain amount of sense to my un-knowledgeable thinking- the SVT came with a sealed 8x10 cab...

So then, sealing my 215 makes sense, right? And it doesn't much matter how I do it- also right?

No, not right at all. If you seal the ports, it doesn't fix your tuning issues. You can't put any speaker in any type of box! It is very important how big the box is. You can simulate how this will take effect on the low-end with a program called Win-ISD. But you will need the Thiele-Small-parameters of your speakers.

 

[Jazzman]

why does epifani not recommend using tube amps with their UL cabs I wonder?

Not according to this: [Invalid or Expired Link Removed]

 

[Passinwind]

So then, sealing my 215 makes sense, right? And it doesn't much matter how I do it- also right?

It arguably makes a little sense if you can find and use some speakers that are designed to be used in a sealed box. Yours likely aren't.

A friend of mine thought that sealing his Avatar 1-12 would be a good idea. It blew up quickly. The 500 watt replacement driver he put in there then lasted only a few days IIRC. When I ran that situation in WinISD I found that he had reduced safe power handling on the low end by something like hundreds of watts. As usual, there's no free lunch.

 

[greenboy]

Count Bassie,

Haven't you been given rather detailed advice on you to get your cab tuned/optimized before, in threads that you started? Those are not going to be good drivers in a sealed cab. You need to either take care of business with tools and measurements, or buy something else ; }

 

[amos]

I have this old Peavey (DIY mod) 215 cab, loaded with BW 1502-8s. It's not reeeeeally tuned, and not ideal, but if I were to seal it's ports, would that smooth-over much of my tuning issue?

I'm going to use it, as it's all I really have for the next few months. I'm not gigging out, just doing rehearsals at home, so it's not going to be a major problem.

I'm playing my Peavey Dyna-Bass Unity through a Sunn 300T. I also have a Schroeder 1210R, and an Avatar 210 NEO. But I'd like to use the 215...

Thanks for your time!

No, it's a myth. Tube amps work with whatever sounds best to you...don't let anyone tell you different.

The myth most likelycomes from the point that cabs like the Ampeg 810 sealed cab totally kickass when matched with an Ampeg or similar all-tube head. But plenty of other people get awesome sounds out of solid-state or hybrid bass amps.

 

[GreyBeard]

No, it's a myth. Tube amps work with whatever sounds best to you...don't let anyone tell you different.

The myth most likelycomes from the point that cabs like the Ampeg 810 sealed cab totally kickass when matched with an Ampeg or similar all-tube head. But plenty of other people get awesome sounds out of solid-state or hybrid bass amps.

Those cabs sound good with just about any amp.

 

[amos]

Those cabs sound good with just about any amp.

+1

I was talking to a guy at a gig who runs a Traynor YBA-200 through one. He told me he has to crank the Traynor. His tone was pretty dirty, I dug it...unfortunately his band was L-O-U-D and both guitarists had 15" loaded bass cabinets in their rigs (Kyuss anyone?), along with their 412s, making it a bit hard to hear him.

 

[greenboy]

Have you guys seen pics of the cab in question, and a description of its changes? It's not what you think, and its been messed around. Yes, the deep BW-driven 215 cabs are awesome, but this is not that ; }

 

[Count Bassie]

Count Bassie,

Haven't you been given rather detailed advice on you to get your cab tuned/optimized before, in threads that you started? Those are not going to be good drivers in a sealed cab. You need to either take care of business with tools and measurements, or buy something else ; }

Yep, I have been given such advice, and have downloaded WinISD... life has not been accomodating for time though, and I've recently come into this tube head. there have been some life issues between me and concentration on this kind of thing.

I still have the same Peavey modded box I had when I was first trol;l;ing about this, and I still have the tweaks to do to bring it close to where it ought to be. that's because I have a family with it's own issues, and lots of work, etc.... but yes, I hear the reproof, and you're right there.

My question is particular to the whole sealed cab idea though, and how important the tuning is as compared to a ported cab. I have heard from a corner or two that there are fewer issues with sealed cabs- and that the tube amps like the sealed boxes better. So I see there's contention!

Anyway, I have to finish reading the replies to this pretty active thread here... thanks for the earth-check!

 

[greenboy]

Not trying to lump on you, but suitable drivers is an issue in this case. Perhaps you should put a pic or two up and we'll take another run at the problem.

 

[Count Bassie]

Have you guys seen pics of the cab in question, and a description of its changes? It's not what you think, and its been messed around. Yes, the deep BW-driven 215 cabs are awesome, but this is not that ; }

I am now surfing with a Mac, and don't have the key commands down evidently... but I'll try and post a pic of the cab here tonight. It was a Peavey RBS-1, a subwoofer cab with 15" drivers in compression chambers. The box was divided in two, and each half had an 8" or so port for it's respective speaker.

Now the box is front-firing, with the divider between the speakers cut open, and ports and fiberglass insulation added. A real shade-tree chop.

Anyway, let me clear something up: I am not asking about what the amp will work with, but whether it's best to use a sealed cab with a tube amp- which I've heard about. I realize the amp doesn't "know" anything.

I started playing bass about 30 years ago, and have not lived exclusively on music. I'm not tech-savvy. And I have responsibilities beside learning how to use WinISD, see... so I haven't been back to run that subject into the ground! When I can get time to learn it I will, you bet. I'd love to build a kick-ass cab and load it with a couple bulldozing 15s.

So on that note, I have understood the replies, thanks all! I leave off the debate...

Rog.