Should I add a subwoofer?

I keep thinking I'm going to investigate an REL, then hear too many things about how difficult it is to integrate them properly and give up. My problem is I only have one place I could put it, and apparently room placement is critical. I use an older tube integrated (Dynaco SCA-35) with B&W DM602's. They are large-ish bookshelf speakers that are rated to about 50Hz, but definitely go lower. I would like that last octave to be cranking a bit more though.

 

A subwoofer should not be used as, or thought of as, as a "Tone Control." A sub should simply provide a graceful extension of bass frequencies that your main speakers can't provide. (Hint: adjusting the crossover frequency and volume is critical for seamless blending of your sub and main speakers. But you can over think it!)

With a sub you should set it and forget it. Having said that, it might take a month of listening, adjusting controls and tweaking the position of the sub relative to the side and back walls before you find the sweet spot that works best with your room and all your music.

If you didn't hear sub frequencies at low volumes in the store, it wasn't a problem with the REL. Maybe the song you played didn't include those sub frequencies. On some songs you won't hear the sub. Also, placement of the sub is very important -- only an inch to the left or right can make it snap right into focus.

I can't believe I'm lecturing like a subwoofer expert -- two months ago I didn't own one! But after a month of tweaking like a mad scientist, you become an expert! (If you have good ears!)

 

That means rolloff begins at 50Hz. You'll still hear some frequencies below 50Hz but they drop in volume after 50Hz. A *rule of thumb is .7 times crossover frequency. So you'd set the sub crossover to .7 x 50Hz = 35Hz. This way as your main speakers are fading away, your sub frequencies are rising to theoretically maintain a flat response down to the sub's rating...

*A starting point. Based on your room, etc. you might need to tweak. .7 works perfectly in my environment.

 

Sorry to hear about the faulty sub.

The REL T2 I use in a 14' by 14' room can get deep enough; hip-hop and dub reggae sound great through it.

One thing I did notice about your PM1s is that they have a minimum 5.1 ohm impedance; you could try, as a free stopgap to the bass problems, hooking them up to
the Primaluna's 4 ohm taps. It might help with the bass issues, but maybe at the expense of the rest of the sound. At least it'd be free...

 

I've been listening to a few small subwoofers, and seem to prefer front-firing vs. down-firing, no matter the brand. Has anyone else found that for music, front-firing is easier to listen to? Maybe it's psychological, but the front-firing format seems easier to 'match phase' with the speakers. There are other important differences from brand to brand, but I think I'm sticking with front-firing. Plus, I don't need to activate my hardwood floor any more than the music does already.

 

Position is also critical in getting the most bass from your main speakers. I started experimenting with toeing in my B&W's, and toed them in gradually over a period of time. After a while I noticed the bass was almost completely missing in the listening position, but there was a ton of bass stuck in the corner. I moved them back to face directly forward with no toe-in, and the bass locked into the listening position. This is one thing that makes me leery of getting a subwoofer -- I only have one place it can go, and odds are it won't be the right place.

 

Brian,

You should consider Jim Smith's "Get Better Sound" book, or his DVDs.
He does a wonderful job of explaining how to set up your stereo to make the most of the room you have it in.
I have used this as a reference for some time, and while it may be a little tedious to go through the process, it does WORK!

It addresses bass optimization, with and without subwoofers.

I got mine a few years ago, and it was less than $50. To date it is has paid for itself many times over compared to any other "tweak" I have attempted.

It might well do the same for you,

 

I'll buy the book now. Are these videos available to watch online anywhere? I don't have a video player in my listening room and I'm guessing I'll want to watch these in there so I can tweak as he explains.

 

Wow Brian, your head must be spinning by now. Good luck.

As a loudspeaker design engineer, here are my thoughts (some of which echo previous posts).

1) Ported speakers use the port for more output at the bottom of the bass. Below the port tuning frequency, they act like a big leak, and let the woofer flop around mercilessly. I could not find the PM1's tuning frequency, but in a speaker of that size it is not going to be super-low. So any very low bass will just flop your woofers around.
- B&W has plugs to either seal the port, or (at least on some models) tune it lower. This may help you a lot.

2) Your speakers are well regarded, but hey, the woofer is JUST 5" IN DIAMETER!!! Bass volume requires moving a lot of air-a 5" can only do so much. You are NEVER going to achieve really high volume with loud, bass-dense pop/rock music (i.e. Motorhead) with 5" woofers alone, no matter how much you fiddle with placement or room treatment or whatever.

3) Adding a sub can add bass volume. However, unless there is a high pass crossover to cut the low frequencies out of your PM1's, they will still be straining to TRY and put out that bass. So if port plugs don't fix things for you, you are in a tough way. Your PrimaLuna is simply not designed to accommodate a high pass crossover. You'd have to put one before the PrimaLuna which rather violates the concept of having an integrated.

4) It is correct or maybe not to say that the subwoofer will mess up the sound. There are a LOT of factors contributing. The PrimaLuna folks obviously have a purist opinion. My opinion is that farting speakers are messed up sound, and no good.

Maybe you need bigger B&Ws...

 

I just un-toed (or is it toed-out?) mine and the sound improved a lot. The soundstage all of a sudden got deeper and taller. Then I threw up the tri-traps I just got from GIK. Amazing. Can't wait to get the rest of my acoustic treatments up later today. Hopefully I'll sell the big ass dresser that's keeping me from finalizing positioning and have the room completely done by Saturday.

 

I've heard longtime audio people say that lack of perfect sub placement can be overcome by tweaking the crossover point and volume. I only had one place for my sub, but it has about 3 feet of play left to right and a foot or so from back wall.

Turn's out about 15 inches from side was perfect. If you have a placement spot that is roughly 8 inches away from your back wall and a foot or two away from sidewall, and generally behind (doesn't have to be directly) a main speaker, you can dial in bass that is satisfying.

A friend gave me a subwoofer test CD (it's just a compilation of different music material that goes WAY low at certain points) and it seemed like the sub wasn't working until this one freaking note on the bass was hit hard -- it was scary cool. I felt it in my chest. Talk about feeling the music! Wow!

 

Thanks for this. I just added some acoustic treatments and was thinking how great the bass was actually sounding on "Wildflowers" (on CD). Then I put on the new Afghan Whigs LP. Lots of low frequencies there on track 1 and they are definitely exposing the weakness of these speakers. Just farty muddied bass unless the bass is very well defined. Sigh.

 

You know, it seems like I'm ONLY getting these bass issues on vinyl. Is that the problem? If it's just the vinyl, is it a problem of the speaker or maybe something else?

 

Brian, I'll second the book/DVD by Jim Smith. Believe it or not, I'm lucky to happen to live about 20 minutes from Jim. He was able to come out to my home and do his room setup, it was amazing what he was able to do with tweaking placement and room setup. Listen carefully and try to implement what he talks about. He knows what he's talking about. Have you decided to go with another subwoofer yet?

 

Man, I wish I had found that guy when I lived in Atlanta. I had a $25K system in my loft that I just never did get dialed in (high ceilings, concrete floors, big open space and brick walls are not the audiophile's best friend).

I'm going to hold off on the sub until after I finish the room treatments and get placement right (unless I find a great deal on something). Now that I've put in some acoustic treatments, I'm thinking that the tri traps in the corner aren't going to leave me enough room to place a sub unless it's fairly compact.

Also, I'm realizing that the bass mostly sounds great. It only gets farty on LP's and only when there's a song where there's a lot of low level frequencies at the base (not bass) of the song. Seems like that's what overwhelms the speakers. Hard hitting but tight bass sounds great and musical. Thoughts?

 

Damn! I thought that I did a fairly good job of driving myself crazy...seems I have competition!

1) Can you provide a link to the room treatments you are using?

2) Which audio dealer do you use in SF? I lived in SF and bought my gear at two places: Music Lovers in Berkeley and Analog Room in San Jose.

 

I don't have a downward firing/hardwood floor problem but a friend of mine placed a 12 inch carpet square under his downward firing subwoofer and he says it helped. I don't know what his sonic problem is/was but I know he's a endless tinkerer perfectionist so it must have improved something.

 

Ha!!!

1. I bought this room kit from GIK. I also added 2 additional panels for my ceiling to cover this big ass recessed sunlight. I'll be adding 3 panels to sit behind my speakers next. http://www.gikacoustics.com/product/gik-acoustics-room-kit-package-4/
2. I'm buying most of my stuff from AudioVision (www.audiovisionsf.com). I bought my speakers from another dealer, but had a bad experience with the owner though the guy who helped me was great. I suspect my next upgrade will be to KEF Reference 205/2's or maybe Dynaudio C2's or C4's. But that's going to have to wait around 6 months or my fiance will flip out. Hard to sneak in new speakers and she already thinks the acoustic treatments are going over the top.

 

I'd be worried about it muddying the sound . . . theoretically, anyway. But if it sounds good -- why not?!?

 

Thoughts? You are right on the money re room treatments. There is NOTHING that can cure room problems other than fixing the room. My room is a big issue, and while my SYSTEM is great, and sounds very good at home . . . I can hear the ringing in the room and know that the virtual lack of any absorbtive materials in the room (one leather couch, no rug, no draperies, hardwood floors) is to blame.

 

Yeah, when I moved to San Francisco I got rid of my entire hi-fi setup. Ended up in another loft with concrete everything, huge bays of windows, 20" ceilings, etc... pretty much an audiophile nightmare. Held off getting anything for 3 years.

Then my fiance bought me a cheap record player for christmas. First thing she says as I opened it, "I'm sure you're gonna wanna return this and get something better." I just smiled. I actually waited 3 months to open the record player because I knew once I did that I was going to rekindle my addiction. Sure enough...

Luckily, my fiance really wanted to move our bed into the spare bedroom (better view and ventilation). That gave me a decent size room to turn into my first real listening room. Really nice because I'm now working from home so I get to listen to music 10+ hours a day.

 

I'll bet that if most of us drank two scotch on the rocks before a listening session, our grear would sound fabulous!

 

I would have taken wood shop in HS if I'd known I could have built a turntable! Whoa! Fugly! http://www.audiovisionsf.com/?page=detail&product_id=2037

 

In person that turntable looks great actually.

 

I have seriously considered room treatments from them. May be my next step.