RB-5's Why doesn't this sound good?

[BS Button]

Installed in the Cabinet surrounded. Figured it would be OK. Wife loves the hidden look...Why does it sound so bad?

[BS Button]

New pre, driving a trusty Aragon

[darylomer12]

Why does it sound so bad?

Becuase they're rear ported speakers. You need to take them out of that cabinet and place them far enough from the wall so they can breathe. If taking them out from the cabinet isn't an option, your going to need to purchase another set of reference bookshelves that are front ported ( RB-25- RB-35- RB75-RB-61 or RB-81).

[BuyOtherSoundEquipment]

Why does it sound so bad?

Becuase they're rear ported speakers. You need to take them out of that cabinet and place them far enough from the wall so they can breathe. If taking them out from the cabinet isn't an option, your going to need to purchase another set of reference bookshelves that are front ported ( RB-25- RB-35- RB75-RB-61 or RB-81).

+1

WAF and excellent sound rarely mix, and this is one of those situations where they don't mesh. Get those bad boys up to ear level and have a listen.

[Fish]

I think there are a few reasons,too low,too close together,as was mentioned,rear port=no in cabinet.I had these speakers up against a pair of JBL twin 10" floor standers,they totally dominated the larger speaker for output at same volume.They sound great at about 8-10 ft apart,26" off floor..

[philipbarrett]

2 other issues may be in play:

1) nice, shiny cabinet door is acting as an additional baffle causing reflections

2) gap between speakers & cabinet is acting as a comb filter for the resonances produced by the cabinet itself which is then combining with the direct sound

In studios we would either free-air the cabinets (hanging from chains) or build them into a soffit then pour concrete around them (obviously only good for monitors that can be serviced from the front). Even a hard pack of fiberglass insulation around the speaker was not enough to kill #2 above.

[colterphoto1]

let me put it this way..

you know those LaScalas you used to own? Did you ever turn them around and fire them into the closet? That's what you're doing with the bass in these RB-5's. They need to breathe. The panels on that cabinet are probably vibrating, buzzing, sounding honky, muffled, boomy, and tubby, right?

[BS Button]

Seems like they lost quite a bit of efficiency, as well. Boy they sound like garbage in there. They sounded so, so much better upstairs on top of the Cornwalls.

BS Button

[SWL]

1) nice, shiny cabinet door is acting as an additional baffle causing reflections

2) gap between speakers & cabinet is acting as a comb filter for the resonances produced by the cabinet itself which is then combining with the direct sound

A while ago I situated two pairs of RF-7's up front as mains.......two on each side, side by side. Something about having the two speakers right next to each other just did not work. One pair on, the other pair off and vice-versa I just couldn't get it right. It was like the reflection off the other speaker cabinet was the problem.......which sounds like part of what your RB-5's are dealing with in that cabinet.

[philipbarrett]

Not reflections but your drivers are interacting with each other. Imagine 2 sets of ripples on a pond, as they meet the audio waves combine at certain frequencies & cancel at others causing massive comb filtering.

If you've seen double clusters at a rock concert (Springsteen used them), normally the inner pair is handling vocals & the outer the band. Because the sources are diffierent the interactions are minimized (somewhat anyway LOL).

[MikeMilliken]

AND... besides the bass issue from the port exciting resonances in the flimsy backing on the cabinet.........The cabinet backing is acting like a speaker AS WELL, MAKING ITS OWN MUSIC.

Sorry about the caps, I got "sausage fingers"

Diffraction is a big issue there as well, the board's in the sides/top of the cabinet are interferring with the speakers radiation pattern and causing lots of evil. If you sit them on top of the cabinet it will improve 100%. In addition to the problems from the rear port, the woofer "sees" (has 1/2 space gain, 3/6 db in theory) every wave length that comes out of the front of the speaker that meets a boundary that it closer than the length of the sound. Comb filtering was mentioned above, but I think its more boundary gain at all the different frequencies that are equal to and longer than the distance from the nearest boundary they intersect. There will be some rather sharp peaks and dips introduced into what you hear.

Not sure if I said that right......without referring to technical papers that I am too lazy to look for.

In laymens terms, what I am trying to say is you will get a 3db gain from sound emanating adjacent to 1 surface thats distance away is closer (distance) than the length of said wavelength. And then when that surface is gone, you get a corresponding dip.

IE: 20 hz is ... dang forget this stuff.. its been a long time since I had to think..60 feet long, (give or take, I am too lazy to look up the formula) I new this stuff inside/out when I was building TL lines.

if you are at the intersection of 2 boundaries (a corner, no floor) you get a 6db gain, or an acoustic doubling in output

If you are at a corner with a floor intersection, you get another 3db's for a total of 9 DB's gain at any frequency longer than the distance to all the intersections from its point of emanation. A corner can be a horn.............albeit an inefficient one compared to Mr. Klipschs.

Without getting the formulas out, I'll take a guess that you have 5-7db gain roughly centered at 2500 HZ and some corresponding dips because the side of the cabinet and the top roll back at 90 degrees (no more boundary,no more gain) and... that your speakers sound like a PA horn at the ball field. with greatly exaggerated vocals and that they are buzzing (the cabinets own music), with little bass, since its energy is being wasted on exciting all the vibration modes in your cabinet.

This is "sort of" why Klipshorns have to be in a corner to make bass........they are not only using the wall to continue the horns length, they are also getting gain in the bass frequencies from the wall/floor intersection. Acoustic half space..........

If you insist that I find the formulas I can.........But if you just want your question answered, there ya go .

[Pete H]

Just in case what Mike said was little to technical and prior to him finding the exact formulas, let me try and put this in easy to understand language. Get them out of the cabinet and move them around until they sound the best. LOL[8-|] The 5's are wonderful speakers and I'm doing a simple system with those and a nice small sub in my shop.

[colterphoto1]

Not reflections but your drivers are interacting with each other. Imagine 2 sets of ripples on a pond, as they meet the audio waves combine at certain frequencies & cancel at others causing massive comb filtering.

If you've seen double clusters at a rock concert (Springsteen used them), normally the inner pair is handling vocals & the outer the band. Because the sources are diffierent the interactions are minimized (somewhat anyway LOL).

mmmm nipples on a pond mmmmm

[TNRabbit]

1) nice, shiny cabinet door is acting as an additional baffle causing reflections

2) gap between speakers & cabinet is acting as a comb filter for the resonances produced by the cabinet itself which is then combining with the direct sound

A while ago I situated two pairs of RF-7's up front as mains.......two on each side, side by side. Something about having the two speakers right next to each other just did not work. One pair on, the other pair off and vice-versa I just couldn't get it right. It was like the reflection off the other speaker cabinet was the problem.......which sounds like part of what your RB-5's are dealing with in that cabinet.

You would actually experence a better result by having them one on top of the other; sort an "RF-7 Line Array"....I know a guy with Cornwalls on top of each other with the upper pair upside down (horns toward each other)...he thinks it sounds fantastic (I've not personally heard it).

[philipbarrett]

You would actually experence a better result by having them one on top of the other; sort an "RF-7 Line Array"....I know a guy with Cornwalls on top of each other with the upper pair upside down (horns toward each other)...he thinks it sounds fantastic (I've not personally heard it).

We used to use that technique live when we felt like we'd bought a knife to a gun fight! We called it a "Festival Stack" which roughly translated means "horrid beam of midrange that will carry for ever!" I've seen it done with La Scalas (!!), putting a small piece of 2x4 between the cabinets helps slightly. Not wanting to be outdone in the terminology we called the piece of wood an "audio compensator" and painted them black.

[SWL]

I thought about trying exactly that but didn't because it would look kind of rediculous in my living room. []

[tommyboy]

I'm sure all these have already been said, but........ They're definitley too close together. I don't know about those, but my mains manual says AT LEAST 6' apart. Secondly, they're too low. Stands or another source of height are a must with bookshelves. And like said, they're rear ported, so..........

[Audio Flynn]

let me put it this way..

you know those LaScalas you used to own? Did you ever turn them around and fire them into the closet? That's what you're doing with the bass in these RB-5's. They need to breathe. The panels on that cabinet are probably vibrating, buzzing, sounding honky, muffled, boomy, and tubby, right?

I have had RB-5s for a long time. Now in the bedroom.

Mine are anchored to a 35 pound lead filled Sonus stand. I think 24 inches high.

Yours are :

1. They are too low to the ground.

2. You cannot align them to optimize the soundstage. get them more to the outside walls and toe them in not too close to the walls.

3. The port cannot breathe.

An excellent WAF concept but the speakers are no in an environment to perform at their best.

[SilverSport]

I have a pair of Mahogany RB-5s sitting atop my Quartets powered by an Outlaw RR2150 retro receiver...I hadn't listened to them in awhile...they sound great...won't unseat the Quartets but they are close and not only were the Quartets a more expensive speaker in their time...they are about five times the size of the mighty midget (perspectively speaking) RB-5s...very nice speakers and better than I remember them sounding...

Bill