B&W Owner's Thread - Page 122

Guys I am wondering what the crossover to the subwoffer should be set at?
60 or 80 Hz?

I have the 600 Series all around for 5.1 surround sound. Could not be bother for 7.1.

Need more detail on which 6 series speakers you have.

Well I finally received all my 3 front speakers 800Ds and HTM1D and started the amplification tests.

First, I drove my 800Ds with my HALCRO MC20 and the HTM1D with my Onkyo 905. The Halcro did manage to drive the speakers up to a certain volume properly (-18db on the Onlkyo) but after that it went into protection mode by switcing off one channel (one time but I stopped).

Yet, the bass was lacking and I attributed that to break-in period but after 70 hours the bass is still not as deep as I expected. So I went ahead and brought home to Electrocompaniet Nemos which I auditioned and will be testing soon (I need an RCA to XLR adapter since the do not accept RCA and the Onkyo only has that).

Tomorrow, I will test the Nemos and write back.


The poor Onkyo can not drive the HTM1D properly and the woofers are not even moving so I plan to use the Halcro with this but I have a question here.

Is there a way to bi-amp the HTM1D with the MC20 (two channel)? How can I make sure that both amp modules will be used since my Onkyo only has one pre-out RCA for the center channel? Do I have to use an RCA splitter?

Can the Halcro'w two channels be bridged somehow?

If they can be bridged, it should say so within the owner's manual. My rotel RB-1070 can be bridged for example.

Well there is no mention of Bridging in the owner's manual so I guess no bridging.

What if I get a split RCA cable that feeds both channels exactly the same signal and bi-amp? I could then connect both amp outs on my HTM1D. Would this be dangerous?

Bi-amping won't accomplish much. Bridging increasing the wattage offered by the amplifier while bi-amping does not (by an appreciable amount).

Anyone familiar with the M-1s or MT-30 setup?

No, this is what I have done with my main HT set-up and my bedroom set-up.
I have been bi-amping my N804 and DM604 speakers that way for years.

I use balanced Cardas Y-cables for my main system, and had AQ special build composite 3m Y-cables for my bedroom system.

You should notice a difference when you start to bi-amp.

I have a similar question regarding the crossover as I am running some old 603s in front, LCR 60 center, ASW1000, and 601s in the rear. I've also never felt like I had the volume set correctly either. It is either too boomy or non-existent.

Any suggestions would help.

Anyone run N804s with an Onkyo 805 receiver? I'm considering these and I think this receiver has quite a bit of grunt, but I'm concerned that it might not be enough. I've read that these are somewhat tough to drive, correct?

Here are the specs on the receiver:

Rated Output Power
TX-SR805:
North American:
130 watts minimum continuous power per channel, 8 ohm
loads, 2 channels driven from 20 Hz to 20 kHz, with a
maximum total harmonic distortion of 0.05% (FTC)
150 watts minimum continuous power per channel, 8 ohm
loads, 2 channels driven at 1 kHz, with a maximum total
harmonic distortion of 0.7% (FTC)
160 watts minimum continuous power per channel, 6 ohm
loads, 2 channels driven at 1 kHz, with

and

Dynamic Power
TX-SR805:
300 W (3Ω, Front)
250 W (4Ω, Front)
150 W (8Ω, Front)

also says power consumption is 9.5 Amps (at the outlet), just for reference.

Currently I have my speakers bi-amped, but there's a chance i'll switch to a 7.1 setup in lieu of 5.1, which would require the use of the other two amps currently used for bi-amping.

I wonder if your problem goes beyond the crossover issue and also involves (1) placement of your sub and (2) a room in need of acoustical treatment or other measures to correct for room modes.

So how do you like the Nemo Electrocompaniet I assume?

B&W 800D with Onkyo!!

This will be long...

Before you set your crossover you want to understand how 5.1 AVR or Pre/pros distribute sound to speakers from a AC3 (or other newer codec) signal. The following is my understanding, but I do not profess to be an expert, so please take this with a grain of salt.

With a 5.1 signal there are obviously 6 discrete channels of sound, and all but the sub channel are full-range (from 20hz-20khz, at least). The sub channel carries low-range information like sound in the 20hz-200hz range, typically explosion and other similar noises on a movie soundtrack. It's the AVR's job to make sure that all (or as much as possible) the information in those 5.1 tracks gets played, no matter what your configuration of speakers. So when you select which speakers you have, it will attempt to redistribute information from speaker channels you don't have into those channels you do have. When you set your speakers to large, it assumes they can play a full range of sound (20hz-20khz) and it won't worry about adding a crossover to limit the range of sound coming out of them. When they are set to small, it doesn't mean they are necessarily physically small (i.e. like bookshelf speakers), but that they should have some kind of limit on the range of sound that is sent to them so that they aren't unduly taxed. This means adding a digital high-pass crossover, usually at a frequency that you can select. My Onkyo 805 lets me select from 40hz to 200hz in 20hz increments, most current AVRs are similar. If I use 40hz, this does not mean that the speaker will get nothing below 40hz, but that the frequencies below 40hz will get rolled off at some db/oct (depends on the receiver, usually either 12, 18, or 24) until you DO get nothing.

Example: Setup - you're sending your speakers THX reference level noise (75 dB equivalent in signal); you're sending them full-range pink noise; you have an 18dB/octave crossover; and you have and you set your crossover to 60hz.

Then at 30hz, you're going to be getting only 57dB of signal, and at 15hz, 39dB. Remember, an octave is a doubling/halving of frequency, and 3dB is a doubling in perceived loudness from a driver.

With that in mind, you want to set your crossovers on the speakers according to their ability to reproduce sound. This is where the +-3dB range spec comes in handy. So with a speaker that has a -3dB of 49hz (pretty common for a ported bookshelf), you might want to set the crossover at 60hz or so to make sure that your speaker is really performing in its optimal frequency range.

The other key to this is that if you have any of your speakers set to small, whatever information the AVR filters out from sending to the "small" speakers gets sent to the sub instead. So you have the sub playing not just the ".1" track information, but the stuff that's been high-passed filtered out. Clearly, if all of the other 5 speakers are set to "large", then the sub only gets the ".1" information and nothing else.

The crossover on the sub works the same way, but it's a low-pass crossover, filtering information above the selected freq. This is to help your sub also stay within it's "comfort zone". Larger drivers typically have more difficulty moving quickly enough to play the higher frequency information, so a crossover for a speaker with a 15" driver is typically going to be set at a lower value than one with a 10" driver(s). Again, the +-3dB freq. point comes in handy. Another factor is that most people use 80-90hz as the "rule of thumb" point at which sound starts to be directional. This means above those frequencies (they are not hard numbers and are affected by many things) the wavelengths for the sound waves are short enough that the human ear can locate their origin. I tend to believe this number is a bit on the lower side of that range, if not a bit lower still. Above about 90-100hz, the male voice dips into the range played by the subwoofer, which (IMO) starts to sound terrible. This is where a lot of subs sound very "boomy". There is typically a LOT more information in the 100-120hz range than the 40-80hz range for most sources, so the sub starts working very hard. This is also why the sub/sat home theater systems usually sound very bad. The main drivers can't go low enough to unburden the sub from playing where it's very uncomfortable, so there are either big holes in the frequency response (read: Bose) or the sub takes up the slack anyway (many of them go up to and beyond 200hz).

So in order to set your sub crossover properly, you have to know

1. what are my speakers capable of producing (match crossover points to speaker +-3dB range)
2. what do I have my small speakers crossed over at (match the low-pass on the sub with high-pass on the speakers, if possible)
3. what are my personal tastes (if you like a very subtle sounding subwoofer, go lower with crossover freq, if you like a lot of boom and loudness to the sub, go higher)

This probably didn't answer your question directly, but the THX spec for the subwoofer crossover is 80hz, so you can use that as a guide. For your specific setup, I'd recommend setting all speakers to small, run 80hz crossovers on the center and rears, 40hz crossover on the fronts (may be pushing a bit, but 603s can handle it I think), and 80hz on the sub.

Note: please don't crucify me for any misinformation in here. Again, I'm not an expert. Feel free to correct where I've undoubtedly got errors.

I would add to your explanation (nicely written!) that if your sub is connected to an AVR, the crossover switch on the subwoofer should be set to BYPASS or to its highest frequency. The crossover circuitry in the AVR will do the job, and there is no need to put the subwoofer's crossover in your signal path on top of the AVR's. In fact, it may even be detrimental to your sound quality.

Many AVR's don't allow you to choose different crossover points for front/center/surround. So should you go with 80 Hz for all speakers (and set them all to SMALL)?

I am actually playing my 683's with no crossover. (I think)

Music is pure 2-channel and 5.1 only gets the .1 to the sub, (which is an upgraded eD A5-350). Nice and simple.

Might be a better solution but I haven't taken a lot of time to tune the sub or add treatments, which I will do later, but for now 2-channel is unmussed with.

2 Channel Rig - B&W CDM 9NTs. Will be going to listen to some 803S tomorrow.

The new CMs have been added to the B&W site.
http://www.bowers-wilkins.com/display.aspx?infid=798

There was a demonstration of these today by B&W Reps at the store where I got my 804S/HTM3S from, but I was too busy today to make it up there.
http://www.audioadvisors.com/

Hey guys. I posted this in the regular speaker forum and someone said I should post it here in this particular thread. So here goes.
I just acquired a pair of B&W CDM1 SE speakers. I love the way they sound. Im not much of an audiophile, but I love music. Ive tried reading alot on here and I know youre supposed to match the amp to the speakers. So Im working on a tiny budget, but I dont need the top of the line stuff anyway.
Wow how embarassing to list my components. Here goes.:
I have a Harmon kardon AVR-20 II reciever. (it has pre-outs)
and my "new" B&W cdm1 se's.
I heard that B&W speakers are power hungry. What is a cheap amplifier that would work with my set-up. Lets say under 300 bucks. I dont mind buying used or old school, whatever. It can be ugly--I dont care. I also have a Klipsch KSW-10 subwoofer. Do I even want to use this with my B&W speakers.?? Is that like a sin or something?? Im just going to use this strictly for music.--two channels. I like all kinds of music- rock, alternative, country, jazz, reggae-- you name it.
Any good used amps that would work for me??
Any additional info or suggestions (or poking fun at me) is welcomed.
thanks guys. Im really new to this stuff, so I apologize.
Rob

Well after comparing the Halcro MC20 to the Electrocompaniet I have to say that the I am impressed! The bass is so much better and the everything sounds like it should. I was afraid that I might find them harsh compared to the Halcro but this is not the case at all. It has the right amount of warmth I like and enough juice for ear-damaging levels.

However, what really holds my system back is the fact that I am using it with the Onkyo and I mostly refer to the musical side of things. I will be buying a proper preamp after I test enough of them and the good thing is that I will test them home. No matter what I really enjoy building this system every bit.

Most of the power needed by speakers is for the bass frequencies. So if you have a powered sub, you don't generally don't need a lot of power for your mains. That's one advantage of using a 2.1 system rather than 2.0. Also, the best position in your room for the flattest bass frequency response may not be the best places for your left and right speakers, which is another advantage of using a sub. On the other hand, integrating the sub with the other speakers is sometimes a problem. I haven't heard any of the specific speakers that you own, so I'll leave it to others to tell you thumbs up/down on them.

Thank you, that helped my understanding of a few concepts.

If anyone would like to chime in with an opinion, I just upgraded to the following:

604 s3's
LCS 600 s3
LM-1 surrounds
- and soon to be joined by a Miller & Kreisel MX-200 sub
Joining an Onkyo TX-SR875
HTPC and HD cable over HDMI and through an older M-Audio Firewire 410 as sources until I decide on a blue Ray player

My time is split between music and movies, but given a choice I will generally better quality for music than movies.

Is there anything I could or should do to significantly upgrade the sound quality and truly make these speakers shine or am I at the point of rapidly diminishing returns in SQ? I'd like to know what possibilities exist for better sound that I can easily reach for without starting over.

For instance would something like an external Emotiva amp http://emotiva.com/xpa5.shtm or something similar in that price range give me a noticeable upgrade in SQ? Or is my existing power enough to render it needless? I've never run a pre/pro system.

One caveat: I'm not a big believer in esoteric inter-connects. I have a co-worker with a $300 power cord from the wall to his desktop system who swears it helps and is needed and I have to shake my head because I know it's plugged straight into 20+ year rat chewed, beach area wire in the wall directly behind it.

Beyond these kinds of subjective improvements, are there any options I could/should consider to make me happily overwhelmed for the next 5 years or so? I will gladly pay for something that makes a noticeable difference but don't want to chase rapidly diminishing or subjective returns.

In your shoes, my first efforts would be to make sure I've done everything I could to place my speakers in the best locations in my room, and to make sure I've done everything (reasonable) I could do by way of acoustic treatment. For example, sound-aborbing or diffusing panels at the points of first reflection, bass traps, removing speaker grilles, getting rid of a sound-reflecting coffee table in front of your "sweet spot." Like you, I don't believe in esoteric and expensive interconnects and wires, but you should have reasonably low-gauge speaker wire. Once you have taken care of these items, you'd be in a better position to determine whether any changes in electronics make a significant improvement.

P.S. I haven't heard any Emotiva equipment, but I see they have a 30-day no-questions-asked return policy, so you could always return equipment that didn't make a worthy improvement in your SQ.

P.P.S. Since you'll have a powered sub, your other speakers will need clean power but not anywhere near as much as if you expected your amp to handle the bass for 5 speakers.

Thanks for the advice, I am going to take it and spend a few weeks adjusting and tweaking their positioning and placement to get the most out of what is here before thinking further. The post X-mas prices should be much nicer as well.

I would think that if the power I am getting is clean, 140w should be plenty using a powered sub but I have never had a pre/pro setup of any kind to know the difference and what it could do for me. Maybe their trial is worth considering ...

hi,

first post here.

i recently purchased a pairs of 804S'. and had the receiver from before. its rated at 110W per channel. very similar to chris campbell's situation. i'm wondering if this is sufficient to drive the speakers. sometimes i do hear distortion or static when i play certain discs - i'm guessing this is what you hear when an amp is "clipping".

thanx

Depends also on the disc you are playing (some are poorly recorded and that might just now be obvious) and the volume you are playing it at. That info will help.

Actually I am a little surprised that you are hearing distortion. You must be playing the 804's awfully loud, or else have them in a very large room, or both. I am driving a pair of 804's with a 120 wpc receiver, and have not noticed any such problems. But I have them in a small room, and have not used them at very high volumes. I also have a pair of N801's im a much larger room, but I am driving them with a 300 wpc Krell amplifier with biamping. The 801's did fine, however, with a 120 wpc Nikko amp, which I used for a short time. I don't think, however, that I cranked it up very high at that time.

When you hear distortion, does it go away when you reduce the volume? If not, it is probably in the recording. You might also consider getting a good subwoofer, especially if you will be using the 804's with movies. Also, with a subwoofer, you may not need as much power on the 804's.

Well, we all started somewhere. My first amp was an Adcom GFA 2535 which I still have today. I had gotten it used for ~$450. It worked nicely for the price with my with first set of B&W speakers, and it never gave me any problems. I would suggest looking for a used Adcom if your on a low, tight budget.

At moderate volumes, the CDM1s should be fine running off your AVR.

If you continue to use the KSW-10, you may notice the bass isn't quite up to par with the rest of the system. Depending on your listening preferences, I'd consider replacing it before getting a separate amp.

As for amps, I'd lean towards a used Rotel in the 50-70wpc range. You should be able to grab one in your range easily.

Guys I am wondering what the crossover to the subwoffer should be set at?
60 or 80 Hz?

I have the 600 Series all around for 5.1 surround sound. Could not be bother for 7.1.

My Setup:
Rotel rsx-1056
Amp rb-1050
Rdv-1040
Speakers Dm602 s3
Sub. Asw600

80HZ the amp will work less and the heavy load will be on the sub, plus your speakrs will sound a lot cleaner as well. But you can also experiment and see what sounds bet to you.