Can using 2 bookshelve spk with two subs give good full range sound.

[Ash]

Hello everyone. This has puzzled me for quite some time now. Any comments regarding this will be highly appreciated and will help me not waste money, thanks.

I want to have good HT and be able to listen to decent stereo sound. I noticed from auditioning receivers and (surround pre-amp / amps) that the best stereo sound that can be achieved (from HT equipment) was by using "direct sound" mode (signal bypasses all processing and is fed directly to the amp).

However, in this mode, the full frequency range is sent to the Left and Right speakers. Therefore, floorstands would be ideal. However, my Left and Right speakers are the N805 which are bookshelves and are limited in the lower freqs.

I started thinking of a solution, and this is what I came up with. Please tell me if this will give good results.

I know that my subs (two B&W ASW675) when used in a system with a seperate pre-amp and surround amp can be used to function as part of Left and Right speaker (will work in stereo). This is possible by connecting the right channel from the pre-amp to one sub, and connecting the Left channel to the other sub. Then set the cross-over freq in the sub accourding to N805 capabilities. The remaining signal is then sent to the amp and then to the left and right speakers (N805).

My first question, is do you think that using the above set-up will give good stereo sound, comparible to floor-stand speaker. Or will the bass be in-accurate?

Should I persue this set-up by buying a seperates surround pre-amp processor and surround amp (the above set-up cannot be made without seperates) (thinking of getting the new Arcam). Or should I just give-up on getting perfect music (with my current speakers) and get a regular surround receiver and save the big spending that I'm going make if I go the seperates way?

Bear in mind that my next purchase is going to be a surround processor/amp or a surround receiver because my current one sucks. Furthermore, I do not wish to change any of my speakers or subs.

I can't help the feeling that goes through my head "I wish I bought floor stands", but I wasn't very audio educated 2 year ago

Thanks for your time guys, (sorry about the long post)

[ajpoe]

I had my system setup similar to what you were describing doing. I had a sub on each channel and ran them full range and my 2 channel music in bypass mode. I have floorstanders but they were still too weak for me in the lower freqs so the subs helped out a lot. I thought it sounded amazing. Since then, mostly for HT purposes, I have moved my subs to the LFE channel and set all other speakers to small and cut them at 80 Hz. To use the subs with music, I now have to use Stereo mode instead of Bypass mode... I have done testing switching back n forth several times and I can't say that I can tell a difference from bypass to stereo, and if it is, its very very minimal. But mostly for HT (and somewhat for music), by taking the low freqs out of my mains and using the subs to do the dirty work, I have noticed greater clarity in my mains and a wider soundstage.

Another thing you could do is get an active crossover like the Paradigm X-30 for your fronts and put the subs on them to run full range but still take the low freqs out of the mains. Turn off the LFE and run all the other channels as small for HT and everything will be redirected to your subs on the front channels but you'll still have a full range signal in 2 channel in bypass for music.

[David Meek]

Ash,

Whether the bass is accurate or not is more subject to the design/build of the subs, their integration with the bookshelf speakers, and finally their location in the room than whether your units are a sat/sub or floorstanding configuration. Given the proper amount of time and effort to set it up correctly, your sat/sub configuration can sound as good in stereo as a floorstander. Bookshelf speakers in many cases can produce a better soundstage than floorstanders if they are away from the walls and on good, solid (read filled) stands so don't sell your existing setup short.

As far as integrating the sats and sub(s), that'll take a test tone "sweep" disc, an SPL meter, some music you are VERY familiar with and a few hours of your time. Simply, you want to get the output across the overlap to be as smooth as you can get it. Once you've established that to your satisfaction then slowly move the sats around in 1" increments (I'd start with the face of the speakers at least 18" out from the back wall and 24" from the sides - if possible) until you find a decent soundstage, then start adjusting the toe-in to bring it all into sharper focus. At that point you'll want to check the sweeps to see if anything has changed and re-adjust to get the SPLs per tone balanced accordingly.

Hope this helps on the speaker part of the issue.

Regarding the other electronics, I'm as much of a music person as a movie person, so I'd go with the best 2-channel components I could afford and then build the HT portion around that (if you can't have 2 separate systems).

[dBeau]

The X-30 is nice and works quite well, but if you are looking to control stereo subs, you might also consider the Outlaw ICBM. For either of these devices to work effectively, you'll want to put them between the pre-amp and the amp. You didnt mention what you are currently using for a reciever. Does the back panel give access to the pre-outs and amp-ins? If not, an upgrade is about your only choice.

[Ash]

ajpoe,

Thanks alot for the comments. I'm happy to hear that you got good sound on your system while using the set-up I'm thinking of. Regarding the X-30, the B&W ASW675 has low-pass frequency control and Line in and Line out, can you please explain how the X-30 will be diffirent from that.

[Ash]

David,

Thanks for lifting my spirit with your comment regarding bookshelves. It is true what you say regarding the proper set-up and placement of the sub to get good sound.

I have to say that I don't have an Ideal placement for my system, I have my fronts only 1.5 feet away from the back wall, I can't move them any further. I have each sub placed next to the right and left front speaker (I think this is a good location). The room floor is made out of tiles, therefore, there is a lot of reflection, but I can't do much about that (cause the wife will strangle me). The room is also rectangular in shape and I have the system placed in one side of the room, therefore the left speaker has a wall on it's side and the right speaker has open space to its side. But these are things I have to live with until I can move into a house that I can have a separate HT room.

I have very good stands for my speakers I had them custom made, they are extremely heavy maybe 25-30 kilos each, they are also filled with sand.

However, I'm not sure what do you mean with a "sweep" disc. Can you please clarify.

[Ash]

dBeau,

I have a Pioneer receiver that cost $240 (it sucks big time), I also have $100 Pioneer DVD player (I spent all my money on speakers). My next purchase will definitely be in that area, I'm considering to buy a separate pre-amp processor / surround amp perhaps the new Arcam AVR700/P1000. As you said, this will enable me to use the subs with my front speakers.

[Ash]

I'm also considering the Arcam because I read that they perform very will in setreo mode, this is supposed to be one of their objectives when they make the HT equipment.

Guys, lets say that I bought the seperates and connected the subs to my front speakers. Do you think I should get an additional sub for LFE channel or the fronts will be enough?

[ajpoe]

ajpoe,

Thanks alot for the comments. I'm happy to hear that you got good sound on your system while using the set-up I'm thinking of. Regarding the X-30, the B&W ASW675 has low-pass frequency control and Line in and Line out, can you please explain how the X-30 will be diffirent from that.

If you want to run your speaker cable to the subs first and then out to the mains using the built in crossovers, you can do that. My subs do not have that feature so I didn't think off the top of my head. However, I do think you would get cleaner sound if you ran subwoofer cables to the subs from the pre/pro and speaker wire directly to the main speakers from the amp. You could test it out first and go that route if you weren't happy with the results, but its not something you can do until you upgrade your receiver. As far as the X-30 is concerned... you'd need a pre/pro and amp combo also. You could run the front L & R preouts from the pro to the X-30 and the high passed signal to the amp to run the mains and the low passed signal to the sub and use the active crossover to dial in the best blending point.

The 'sweep' disk that was mentioned is just an audio calibration disk that has frequency sweeps on it. These are basically sound tracks that move (sweep) from usually a high to low frequency over a period of time so you can use an SPL meter to find the best place to cross over the subs/mains for best blending.

[Ash]

ajpoe,

Thanks for the explanation.

You are right I do need to buy pre/pro and amp combo, this will definatly be my next purhcase.

Do you know where could I get a "sweep" disc and can you please explain to me how can I use the SPL meter to find the best place to cross over. I just bought a SPL meter and not sure how to exactly operate it.

Thanks alot for the help, I appreciate it

[ajpoe]

I believe you can purchase something like the AVIA DVD off Amazon. I borrowed it from the local library.

AVIA explains how to do most everything so you can learn a lot by watching the setup instructions prior to calibration. There are several tests on the disk like the pink noise generator found on most receivers so you can calibrate all speakers to the same level. I.E. you would go to the front left channel and dial it in to 75 dB on your SPL meter (C weighting, slow response) and do not touch the volume control anymore. Then move to the other channels and adjust the level dB +/- until you get a reading of 75 dD on the meter for each channel. Your levels are now set. As fas as finding a crossover point. This is where you'd use a sweep from high to low and watch the spl reading on your meter. Try different crossover points and see which one yields the least amount of movement in the dB reading. You do not want any large peaks or dips in your SPL reading as you go across the frequency range. You may need to play around with the phase setting on the subwoofer also.

[Ash]

AJPoe,

Thanks alot, that is very helpful. I think I will purhcase the DVD to help me clabirate my system.