Subs... Do they have to match?

[platinum]

I purchased a 10 inch sub (PSB Subsonic5) 6 months ago to match my LCR-600 and 602S3s... During the first few months I was really impressed but as time went on i kinda noticed the bass was really lacking since the AV room is like 15x20 ft... Cus of that I'm thinking of purchasing a brand new sub and add it to the one I currently have...

Question:

Is it highly imperative to match both subs? I don't have an open budget that's why I'm thinking of purchasing the cheapest 12 or 15 inch sub. But the guy selling me the subs was telling me it has to match...

Front and Center should match right? But bass? Should it? Thanks in advance...

[jimmyp58]

Great question. Essentially, what does a sub do? It moves air. Some do it better than others. Some are more efficient. Some are quicker. Some go deeper. Some are more musical. A sub's performance is also dependent on it's location in the room (i.e., placement --- the more it is in a corner, the deeper or sometimes more boomy it is). Some subs are just 'thumpers'. Lots of variables and can be tricky to control.

At one time, I had two different brands. Then I had the same brand for both but different models.

Placement is crucial. Where do you have your current one placed? Where are you planning on putting the second one? If you will have both in the front then yes, you really should have both the same. But if you have one in the front and one in the rear then no, they can be different (different model or brand). Regardless, IMO you need to do this carefully. If you have a front and rear setup, you'll have to have one out of phase with the other so they don't 'cancel' each other out. I would try to bring home a couple of second subs (if you can find a store that will let you do it) so that from a performance characteristic standpoint, the second one doesn't negatively effect the primary's performance --- check to see how the second one complements the first. Before doing anything with purchasing a second sub though, I'd first experiment with the current one you have (if you haven't already) by moving it around to see if a different placement changes it's dynamics. Who knows, you may find that simply moving it to a different location enhances it's performance and you don't have to purchase a second sub.

Without knowing some of the answers to the questions I've asked, it's difficult to say if your guy has this right or not.

Hope this helps.

Jim

[sikoniko]

I know from car audio that different size drivers perform differently. Perhaps if you already have a 15, adding a 12 or a 10 inch sub or vice versa could add a new level of low to your sound.

[BlazeMaster]

or you can try selling yours 2nd hand to someone else or on Audiogon and then take the money to buy one beasty sub.

[Wayne A. Pflughaupt]

I doubt you’ll find any cheap 15” subs. Most of the cheap ones have small drivers.

Generally though, it is not a good idea to have non-matching subs. Especially subs that are drastically dissimilar, like the ones you’re considering. I would expect that a cheap 12” sub would play louder than your PSB, but not go as low.

But let’s say for the sake of argument that maximum output of both subs is the same. We can assume that the 10” PSB sub will have better extension; let’s say it gets down to 25Hz, but the cheap 12” only goes to 40Hz. Assuming again that both subs are in the same corner, adding the 12” sub will increase overall output by about 6dB across its operating range, 100 to 40Hz. But below 40Hz the cheap subs rolls out, so that means response of everything below 40Hz is down a substantial 6dB.

By contrast, if only the PSB sub was being used, response would not start to drop off until 25Hz.

Thus the addition of the cheap sub will increase overall output, but at the same time it will “drag up” extension, because only one sub will be reproducing the lowest frequencies.

Regards,
Wayne A. Pflughaupt

[Burke Strickland]

In essence, it boils down to:

As long as they are of comparable quality, subs don't have to "match" the main or suround speakers. But just as you would use the same brand and model for your front left and right main speakers, if you have more than one sub, the subs should match each other.

Reiterating:

If the sub you have now doesn't go low enough, (rather than just not being loud enough) then instead of adding a different sub to the mix, it would be far preferable to replace it with a more capable sub. If the current sub is adequate with regard to range but just needs volume reinforcement, (goes deep enough, but bass needs more volume to fill the room), then if changing placement in the room of the existing sub doesn't solve the problem, adding another one just like it might be the ticket.

As Jim points out, room placement plays a BIG role in sub performance. Having one sub to hit deep notes and another to fill the room typically just wouldn't work out very well. One correctly-placed really powerful sub, or more than one sub with like characteristics (being of same brand and model) placed to reinforce each other, would be the way to go to achieve the bass you desire.

Good luck!

Burke

[RobP]

Yes your subs should match, If you have a problem with not enough bass and not enough funds, I would suggest the DIY sub kit that uses a NHT 1259 12" woofer, it has a 3db down point at 25hz and is a very clean sub for both 2 Channel and HT. I think Madisound has the kit. I use one in my second home theatre setup in my bedroom that has B&W 602's and it works very well with them, the room is 16x30. This sub will really surprise you.

Good Luck!
Robert P