Mixing Ported and Sealed Subs

[opimax]

I am about to receive my repaired Velodyne amp for a SPL1200r, a 12 inch sealed sub. I use it in as a 2nd sub w/my B460 which is ported. I will be running both off a SMS-1 in a home theater set up/also my 2 channel system. The people at Velodyne said it is a known that ideally not to run a ported and sealed sub together. Well, it isn't known to me so I wondering facts/opinions on how extreme an idea this is. I am sure it is not as bad as running 2 subs out of phase for example but is there more effect than ceramic wire stands across your floor? (I can't tell that different to those that can). The rest of the equipment in the set up(250TI and 120TI ) is ported.

And lastly there are a few configuration options that could be used. For example set up the b460 as a sub to only the 250 through a bx63 clone (Paradigm) so when to 2 channel full range and tap off that signal rather than the sub out and leave the Velodyne on the sub out. for HT work. Or any combo that can be done.

I will end up with what sounds best top me of course but welcome all opinions and facts and hope I can tell the difference if you post a reply :)

Mark

[rdgrimes]

The people at Velodyne said it is a known that ideally not to run a ported and sealed sub together.

Balderdash. What IS important is the placement and tuning of each sub. And of course what you're listening to. Most of your average stereo content doesn't have much below 40Hz to begin with, but that doesn't mean you can't use a sub with those 250ti in stereo mode. That is, after all, what the B460 was designed for. For multichannel HT duty you want all the sub(s) you can muster, so I wouldn't eliminate the B460 from the HT setup. Plus, the B460 is probably the strongest of the two for VLF content.

I'd start with the 2 subs on opposite sides of the room, or front and back. Then adjust output to balance each one's strengths. I'd want separate level controls for each sub, PLUS a master level control of possible (which can be your processor/AVR)

I run my PS1400/PT800 stacks (very similar to your 250ti) on a 40Hz crossover to subs. While the PS1400 also take the sub (LFE) channel input its also going to my HTPS400 and Array 1500 on opposite sides of the room. I've played around with stereo subs, and "front-back" configurations in my processor, and quickly came back to using all 4 subs all the time on a single mono output.

A lot depends on your room, its volume and shape.

[christo]

Mixing Ported and Sealed Subs


In my two channel system with two Array 1500s I added the DSPeaker Anti-Mode 8033 Automatic Subwoofer Equalizer and I’m very pleased with it.

http://www.dspeaker.com/en/products/anti-mode-8033.shtml

For those of us that don’t have the tools to EQ a room properly it’s a good fit. Once the calibration is done you can play it in un-calibrated or calibrated mode to compare and yes there is a large difference. I find in the calibrated mode the bass is deeper and more powerful.

It could possibly be of use in your situation, but I would closely review the connection options to ensure it is a fit.

http://www.dspeaker.com/en/technology/anti-mode-technology/anti-mode-connection-examples.shtml

[Mr. Widget]

I will be running both off a SMS-1 in a home theater set up/also my 2 channel system. The people at Velodyne said it is a known that ideally not to run a ported and sealed sub together. I don't believe there's any problem using a vented and sealed subwoofer in the same room. That said, I think what Velodyne was talking about was not to use both of them with the same SMS-1. I certainly would not do that as boosting the low frequencies appropriatly for the sealed subwoofer could damage the vented subwoofer and certainly add distortion.


Widget

[grumpy]

Helped out some over at TiDome's with four subs, two ported and two sealed.
definitely sounded better with separate crossover and EQ optimizations for each type
to be sure they played together well vs fighting each other.
HTPS-400 and PS1400 I think...

Even the JBL BassQ product had a hard time with this, ... not knocking the product,
but this required some real analysis and experience as it was not a simple case.

If using different subs, I'd think most of the time, a common output to all
would not be optimum, ...and possibly detrimental.

[opimax]

Thanks for responding! Let me respond to each post

The friendly person was a customer support rep may not have been the absolute techy. He specifically said to run them both of the SMS. I can see this is a poor idea remembering the fairly large discrepancy in the individual graphs they produced the last time (and different house). The velodyne went to 20 or lower, the b460 needed that big boost to get to maybe 25.There is an autos eq in the controls for the Velodyne and remote control, it can be controlled independant of the SMS/b460. I was told to not run the auto eq and run both off the SMS. :dont-know:. Previously when I used them together I set the xover on the velodyne to the lowest ,40hz it would go and I think I had them both on the SMS. I will play with room placement and I have only mono output anyway.

I look forward to the day I have more toys and life is simpler but I don't think dealer is on my near future.

i think I responded the the other posts already 😀

i am wondering about adding 2 individually eq'd together...is the sum going to be smooth or "spikey"?

[allen mueller]

It is my understanding that there could be potential issues with cancelation if the subs are adjacent to each other due to the group delay present in a vented enclosure. Weather or not it is significant enough to notice you won't know until you try.

Al