Budget Strategies forTightening up Bass?

I'm with Bigby on this one - TREAT YOUR ROOM! Build very thick DIY Fiberglass filled bass traps with a generous air space (e.g. 6"-8") behind them. I'm sure your $350 will go along way of buying some lumber and OC701 fiberglass or equivalent and some cloth to cover them.

Room treatments will put to shame (I'm exagerating on purpose to make a point) any kind of 'tweaks' associated with cables or amps or tubes etc in proving you with sonic dividends that far exceed your $350 investment. You will notive that the more elaborate systems here on A'gon usually have acoustically treated rooms. Coincidence? I doubt it!

My AV system is set up in a large irregularly shaped open living room. I found that walking around room with music playing helped me find the bass nulls and peaks. Changing my listening distance from speakers significantly affects bass response. Moving my speakers just a few inches closer together made a big improvement in my room. A bass trap in the corner of the smallest part of the room was also an improvement. A new stiffer floor help also helped as did my 100lb sand filled speaker stands I built. Jim Smith's Get Better Sound has a lot useful information on this subject.

Based on the impedance curve of the Prelude http://www.stereophile.com/content/silverline-audio-technology-prelude-loudspeaker-measurements, Silverline may not be the best match for a tube amp.

Oh, really? Here's a direct quote from the manual:

About Power Amplifier

The standard impedance of all Silverline Audio speakers is 8 ohms. Their exceptionally stable impedance loading favors single ended tube amplifiers, as well as low powered solid state amplifiers.

Care to retract your statement?

I have these speakers and not only do they put out tremendous bass, but also clean and fast bass. They are powered by the Rogue Audio Cronus tube amp and the combo sounds magical with the VPI Classic and Lyra Delos cart. I don't agree with opinions these speakers are not tube-friendly. I do agree, however, that impedance matching can help. I believe the nominal impedance of the SR 17.5s is 8 Ohms and switching from the 4 Ohms to the 8 Ohms taps resulted in fuller and heftier bass.

As a few wise responses suggested, the positioning of the SRs is critical. You had them way too close to the walls initially. I'd suggest at least 2 feet from the side wall and 3 feet from the front wall. I faced a big challenge in my set-up as my room is roughly 12'x11' and I knew taming the bass was going to be a problem. In addition to placing the speakers as far from the walls as I could while maintaining the imaging and the soundstage I preferred, I also treated the room with some dyi fiberglass panels. I bought a box of Owens Corning series 700 2'x4' fiberglass boards from a local insulation materials shop. Ten boards cost me $140. If you have a big supplier in your area, you can get them as cheap as $83. I then bought 2'x4' sheets of particle board from Home Depot and some fabric from a fabric store. It took me about 30 minutes with the help of my girlfriend and a staple gun to make several acoustic panels. I made a few with 2 fg boards per panel to make them more effective in absorbing bass. Considering the size of the room, unavoidable proximity of the listening position to the back wall and the amount of bass these monitors produce, the sound is superb. Speaker placement and room acoustics simply cannot be overstated.

DYI room treatment - bass traps in the corners and absorption at the 1st reflection points. You will be amazed by the results.

Plugging the ports will reduce the excursion-limited power handling above and around the tuning frequency, and increase it below (where it falls rapidly with a vented design). You're not pushing them with a big amp to begin with so I think you would be fine. However re-positioning speakers and/or listening position is the preferred approach; I had been under the impression that wasn't feasible in your situation, and am glad that you were able to try it.

Duke

OK... I did move the speakers; I didn't have alot of room to play with, but now, at a distance of 30" from the wall, rather than 10", the bass is much more defined. In fact, it sounds pretty darned good on well-recorded cds. The sounds-stage is deeper and imaging is better. Could it be better? Probably, but I don't have the luxury of a dedicated listening room. I contacted silverline and Alan Yun asserted the speakers are "desiged to be ported" and that plugging the ports "could damage the woofers". Perhaps this is his standard fine-print disclaimer and does not so much represent an actual risk, but even so, I'm not inclined to start stuffing anything into the 17.5's. For me, they were an expensive purchase. I'm still going to try what others have suggested, in addition to speaker placement.I don't think it has to be a black and white, "this" or "that" approach.

I'm not familiar with the Silverline 17.5. If it uses a ported box, you might try lowering the tuning frequency by lengthening the port and/or reducing its cross-sectional area. Or tightly stuff open-cell foam into it, transforming the system into a pressure-relief type of cabinet. Or seal the port entirely.

Duke
dealer/manufacturer

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I don't post here much because of the large variety of opinions, all of which cannot be right. But this one is so obvious to anyone who has successfully voiced large numbers of systems.

The single most important thing does have everything to with the room. It's locating the best place for the listening seat.

The "best place" is where the bass is smoothest, so that you are not unduly at the mercy of room resonances. All else (such as moving the speakers, changing amps, etc) is of lesser significance. Not that they aren't important, but working with the standing waves in the room - rather than against them - is foundational to the OP's quest.
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"The most important thing in a system is the room and speaker placement."

Also match between amp and speakers.

The rest may help but cannot substitute for getting these two things both right first.

If Stuartk can not move the speakers there is no reason to recommend that he do so...

Forget about wires, cables, footer, sorbothane, and all the other tweaks. The most important thing in a system is the room and speaker placement. Not that I'm a guru or close minded, but anyone who thinks a new power cord or speaker cables will solve an issue like bass response batter than speaker placement is an idiot.

The cables and tweaks can and do work, but not to that extent. They're worthless if everything isn't set up correctly IMO.

I know... I'm going to catch a lot of flack for that one.

Bob-- Thanks. Interesting point, which I'll keep in mind. For now, my goal is to see what can be done with the current set-up. If nothing works, then I'll certainly consider changing speakers or amp.

BOB: My understanding is that Alan Yun designs his speakers with tube amplification in mind. At least I've read that somewhere-- that's not a direct quote from him.
As for the room, it's an "open plan", so the livingroom where speakers are located is separated by a half-height wall from adjacent diningroom and open to adjacent two-story entry. A pretty large space.
MICHAEL:I will look into the sub option. As for reinforcing the floor, it's hardwood, suspended. I can't see covering that with plywood.
MAGFAN: I suspect Vibrapods are not the best footer in my case-- I plan to try alternatives.

See the 'nearfield listening' thread over in speakers.
Vibrapods implicated in bass issue. For better or worse?

Is your floor a suspended wood floor? Can you get under it?

If yes to both, the biggest thing you can do to improve the bass is to brace the floor.

I have two 12' long 4x4s running front to back, (13' deep room) about 5' apart, perpendicular to the joists, held up by 4 of those height-adjustable basement support posts.

I have since added a layer of 3/4" plywood on top of the original floor (w/ Green glue in between.

Everything I do the the floor makes the sound so much better. I know that I could not have the sound I do now had I not braced the floor. Absolutely essential.

-Mike

Not to sound contrarian, I think the sub IS the best bang for the buck (short of repositioning the speakers, if that does the trick) to solve your problem.

There are several great subs in the budget price range by Hsu, PSB, SVS, etc.

Also, I've never found EL34-based amps to ever have extreme control over bass. It's not their strength. But the midrange is usually very good. Work to the amp's strength, and let the sub take care of its weakness.

Just my 2 cents.

Michael

I will explore all suggestions. Although I have only so much flexibility to move speakers, there is some wiggle room. I've e-mailed Alan Yun at Silverline and will get to work experimenting with room treatments and footers first before moving on to wire, amps. Thanks to all!

Yes, well, if the speakers are too close to corners or rear wall, definitely try moving them out away from corners and rear wall. That should ease up the bass.

Once the speakers are located for best sound , then you can assess if anything else is still needed from there.

You got your speakers backed into the corners of your room and the bass is too fat?? Hmm, you don't say.

C'mon man! What Timrhu said.

If you want the most bang for the buck and if you could squeeze a few in the corners,I'd do some Gik tritraps.
They are about23"W and 12" deepif your corners can handle them
Those will make a huge improvement on the bottom end.
you can also make them yourself,Gik has dedicate circle now on audiocircle.

I'm guessing the tube amp driving the Silverline speakers is the culprit for looser than desired (underdamped?) bass in this case?

Assuming this is the case, something like a Wyred4Sound Class D integrated or something similar from Bel Canto or other vendors of Icepower Class D integrated amps might address the issue.

The BC icepower monoblocks I am using have delivered the tightest yet most powerful yet nuanced bass ever on my Dynaudio monitors, which may be somewhat similar to the Silverlines.

Power cords? Speakers cables?
The Silverline SR17.5s put out some serious bass for monitors. Set up and positioning for this speaker is critical and being only ten inches from a corner is going to render bloated bass.
If moving them out into the room is not an option I suggest you contact Alan at Silverline Audio for information concerning some sort of port plug as noted above.

I tried moving speakers 4" further away from back wall-- seemed to make a difference

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If your initial distance from back wall was 10", you may now have almost same distance of the front baffle from rear and side walls.
This seems to infringe one of the fundamental speaker placement rules. It may work for you, but it's largely discouraged.

As for your speaker cables, I've tried many and settled on Speltz anticables, even over cables that list for over $1200.00. There is a clarity, and open clean window on the sound that is beautiful and incisive on VMPS speakers. Can't comment on other speakers bu the Absolute Sound sure loves them too. You can buy them in bulk, easily attach spades and do it for under 100.00. i have a 10 ft. run and and 18 ft. run because my equipment is now on the side vs. between the speakers. I used to have an 8 ft. pair. You can't tell the difference in the longer cables or in a mismatched length. How many cables can do that number and still be clear as a bell?

Rear port, right? Firing into corners...I'd try different schemes of port damping using various plug materials.

My opinion.

Cwlondon-- was that "good luck" with my speakers or "good luck" with my marriage??? ;o)
Musiclug-- I will try brass!
RE: speaker cable and power cords, my speaker cable is 20', so upgrading it significantly will, I'm guessing, cost a good deal more than $ 350, but used, maybe not. Any suggestions?????
I've got Transparent Power Link Plus power cords, now.
I'll try borrowing something else from my dealer, see what happens.

Just a guess, but I have never had much luck putting speakers near any walls, not to mention corners.

If you want to use the room as a tone control of sorts, often better to bring the speakers out from the walls, and push the back of your listening chair against the wall.

Still guessing, but I would think this would also dramatically improve the imaging of your Silverline speakers.

Not sure how this might complicate your decorating, but you asked about tightening up the bass, not your marriage.

Good luck.

its time for diy acoustical treatment..Thick as you can get and not over done.

Speaker cable and power cords. A good power cord will tighten things up - 'A LOT'.

try a VenHaus DIY PC <$100 ea

you may realize other benefits as well

power cords make a big difference and may be all you need

I've found that sorbothane under a CDP makes the bass 'riper', while inverted brass cones make it 'tighter'.

your mileage may vary...

you might also look into a DAC. the different flavors of D to A vary enormously between brands (e.g. theta = kind of gutsy while sony = analogue-y). you'd have to audition them in your system to see if that addresses the problem.

Don't forget to adjust your seating position too!

Rcprince-- I tried moving speakers 4" further away from back wall-- seemed to make a difference. Will experiment further.

By tightening, I mean more focused. I don't have much room to play with re; speaker placement, unfortunately. They are located in corner formed by back wall and hearth. Back
back of speaker = 10" from wall, side of speaker, about 13" from sidewall.

Not exactly sure what you mean by tightening the bass, but if you have a bass hump that makes the bass seem overly ripe you might first try moving your speaker position to see if there is a room interaction that is part of the problem. How close to the back wall are your speakers now? Try bringing them out a bit into the room to see if that has an effect. Certainly the cheapest fix I can offer for starters.