I joined the SDA club

heiney9

I disagree Shurkey and I've been down that path. How you can state AVR's are compromised devices on the one hand and then say the last part of your post is ridiculous. They are compromised devices from input to output, so the last part of your post is nothing but babbling.

H9

Schurkey

heiney9 wrote: »

I disagree Shurkey and I've been down that path. How you can state AVR's are compromised devices on the one hand and then say the last part of your post is ridiculous. They are compromised devices from input to output, so the last part of your post is nothing but babbling.

H9

AVRs are compromised components in most if not all cases. That doesn't mean that it's IMPOSSIBLE to design a good one.
If you're powering a speaker (biamplifying) with two amplifier channels instead of one, and the power supply is robust enough...how are you not increasing the potential current available? The multi-channel amplifier may be deliberately current-limited in each amp channel; in which case using two amp channels doubles the current capacity if the power supply can handle it. Or, each amp channel may be "passively" current limited by the output devices chosen and the amount of heat-sink available--in which case using two amp channels may not double the current capacity, but should still make a considerable improvement.

A third current-limiting possiblility is having a power supply so worthless that the rail voltage drops as the additional amplifier modules output increases. This is a sign that you've bought a bottom-feeder piece of junk; and the output specs will readily show that weakness by dropping the rating--or allowing increased distortion--when all channels are driven. This does not seem to be the case with the AVR in question, which seems to show 140 watts all channels driven at reasonable distortion and bandwidth.

The overall questions are: Can the power supply deliver the goods to multiple amp channels; and does the speaker actually benefit from the additional current capacity. (i.e., how much current do the tweeters handle before frying; compared to the current needed by the midwoofers.)

heiney9

The same reason engaging the other two wheels in a 4 wheel drive vehicle doesn't lead to an increase in HP. Current and voltage are fixed whether you use 1 channel or 6 channels.

H9

Schurkey

heiney9 wrote: »

The same reason engaging the other two wheels in a 4 wheel drive vehicle doesn't lead to an increase in HP. Current and voltage are fixed whether you use 1 channel or 6 channels.

H9

Poor metaphor. Horsepower isn't increased, but traction is. And that may make the difference between calling for a tow-truck, and driving away. If I continue with your metaphor, horsepower is equivalent to voltage, traction is equivalent to current flow. Still, I'm not thrilled with the metaphor.

Adding more amp channels does not increase the voltage. It certainly can allow increased current. Whether that's a usable advantage depends on many variables.

dpowell

Congrats on a great pair of speakers! Start saving now for the XO upgrades. If you think they sound good now, you won't believe your ears with some sonicaps replacing those old worn-out, leaky caps. Also, even if you can't crank your speakers in the apartment, get an external amp so they get some real clean power. I would take a single 2-channel power amp any day over bi-amping them with an AVR.

Toolfan66

dpowell wrote: »

Congrats on a great pair of speakers! Start saving now for the XO upgrades. If you think they sound good now, you won't believe your ears with some sonicaps replacing those old worn-out, leaky caps. Also, even if you can't crank your speakers in the apartment, get an external amp so they get some real clean power. I would take a single 2-channel power amp any day over bi-amping them with an AVR.

This ^^^^^^^^^^^^


Enjoy!!

Crashdot

drumminman wrote: »

Check to see that the speaker cables are connected in phase, that is + amp terminal to + speaker terminal, - amp terminal etc. Also, check your receiver speaker settings to be sure that's not causing issues. Not familiar with the Denon set up so I can't give specific advice. Should have a great center image like the RTA 12's but with a wider and deeper soundstage.

I have wondered if the SDA technology was responsible for the reduced center image and tried removing the cable just as a test, and maybe noticed a tiny difference. I will need to get someone to attach and remove the cable while I am in the listening position to accurately judge this. In general, I plan to use these with the cable connected unless I run across something that sounds awful.

Everything should be in phase, as I've verified the polarity of the speaker cables. I was wondering about that since it is mentioned in the troubleshooting section of the manual. Unfortunately, at the moment I cannot move the speakers closer together due to furniture in the way, but plan to re-arrange in the near future if that may be the cause of this problem. Moving my listening position further back against the wall changes the imaging, but I don't know if that is due to reflections from the wall vs getting into a better position.

This receiver has analysis and calibration features intended to resolve acoustic issues, which definitely help with my other speakers, although these are currently disabled. I don't know if the SDA technology will confuse the calibration microphone, and need to decide whether I should try to calibrate with or without the SDA cable. I suppose the question is whether the frequency response of the speakers changes when the SDA cable is disconnected. I wonder if anyone here has tried Audyssey or MMACC with SDAs.

Thanks

Crashdot

Schurkey wrote: »

Adding more amp channels does not increase the voltage. It certainly can allow increased current. Whether that's a usable advantage depends on many variables.

It is my understanding that these are current hungry speakers, which is why I thought that bi-amping would help. I listen to these at low volume, I just want to be sure there is enough current to keep the speakers from sounding saggy. I removed the bi-amp wiring and don't notice any specific difference immediately. Maybe I could try some test tones with the SPL meter. Since it takes a few minutes to switch back and forth, I can't A-B the speakers with any degree of validity. I may have to consult some Denon experts and see what they know about the amp circuits.

Cheers

heiney9

Crashdot wrote: »

I have wondered if the SDA technology was responsible for the reduced center image and tried removing the cable just as a test, and maybe noticed a tiny difference. I will need to get someone to attach and remove the cable while I am in the listening position to accurately judge this. In general, I plan to use these with the cable connected unless I run across something that sounds awful.

Everything should be in phase, as I've verified the polarity of the speaker cables. I was wondering about that since it is mentioned in the troubleshooting section of the manual. Unfortunately, at the moment I cannot move the speakers closer together due to furniture in the way, but plan to re-arrange in the near future if that may be the cause of this problem. Moving my listening position further back against the wall changes the imaging, but I don't know if that is due to reflections from the wall vs getting into a better position.

This receiver has analysis and calibration features intended to resolve acoustic issues, which definitely help with my other speakers, although these are currently disabled. I don't know if the SDA technology will confuse the calibration microphone, and need to decide whether I should try to calibrate with or without the SDA cable. I suppose the question is whether the frequency response of the speakers changes when the SDA cable is disconnected. I wonder if anyone here has tried Audyssey or MMACC with SDAs.

Thanks

They will sound worse without the cable attached. You need to make sure all the processing is off and that a full signal is going to the SDA's and then as I already mentioned work on placement. It's the easiest least expensive most common issue. Disconnecting the cable and re-connecting it won't really help as it has very little to do with the center imaging since it runs the dimensional array. You either have a positioning issue or a gear issue. Once those are eliminated then start looking at possible connection issues and or crossover issues.

Crashdot

dpowell wrote: »

get an external amp so they get some real clean power. I would take a single 2-channel power amp any day over bi-amping them with an AVR.

I can run the speakers in 2-channel mode without bi-amplifiction on the current receiver, which should be supplying about 200watts at 6ohms according to Denon. I could someday in the future try to find a power amp and run it from the Denon which has preamp capabilities, but will not be replacing the AVR since it performs necessary functions such as lossless network music playback, component switching, and digital playback of high definition audio material. This is considered to be a fairly high powered and high quality AVR, and has an upgraded power supply from the previous year, that has more in common with the $4000 5000 series model, such as low impedance stability. It weighs 38lbs.

Here is the inside of the Denon in case it gives any clues:

I realize that AVRs and/or Denon are not highly regarded, but for me the advantages are necessary. I do have an NAD T763 300w AVR weighing in at 48lbs, with a "PowerDrive High Current HolmgrenT82 Toroidal Power Transformer" that I could test, but I'm not sure I will be able to tell the difference between 200w and 300w. Here is the inside of the significantly less powerful NAD T762:

heiney9

IMO, you need to get the output from the speakers sorted out before worrying about bi-amping or swapping AVR's. Weak, recessed center image should be addressed before all this other monkeying around.

H9

Crashdot

heiney9 wrote: »

You need to make sure all the processing is off and that a full signal is going to the SDA's and then as I already mentioned work on placement.

All processing is off, and full signal is going to the speakers as I have removed the bi-amp configuration and placed the amp in "Pure Direct" mode. Placement is as described in the manual. Speakers are not toed in. They are 10 feet apart (Z), with the listening position 10 feet from the plane where the speakers are placed (X), equidistant from them. Distance to sidewalls (S) is greater than 3 feet, and distance from the front wall is about 8 inches (Y). Distances are laser measured to within 1/4 inch or less. The speakers have been leveled.

heiney9 wrote: »

Once those are eliminated then start looking at possible connection issues and or crossover issues.

Do you mean the crossovers inside the SDA speakers? Thanks

Crashdot

heiney9 wrote: »

IMO, you need to get the output from the speakers sorted out before worrying about bi-amping or swapping AVR's. Weak, recessed center image should be addressed before all this other monkeying around. H9

Probably what I need to do is move over to the studio and record some test tones at various panning positions and frequencies, then use them with the SPL meter to see if I can get any information and compare to what I am hearing. I am generally curious as to how the SDA imaging works anyway, in particular since I would like to mix my own recordings to sound great on these speakers. Can anyone recommend specific recordings for testing these speakers with regard to the center imaging?

Crashdot

F1nut wrote: »

Pro amps are not suited to high quality home audio.

Does a Carver PM-350 qualify as a pro amp?

Thanks

vcwatkins

Congrats, Crash, on getting some great speakers!

Sounds like something fundamental is wrong if you've got it in direct stereo, the speaker placement is appropriate as per your #43, and center image is very weak.

Center imaging for me has depended on a few factors, but is a matter of degree or quality, never very weak or missing. The SDA should be getting you most of the way there. Synergy with other components, room characteristics, room treatments, quality of cabling, all seem to affect the quality, but to a lesser degree. For example, all else being equal, Rotel and Krell amps on my office CRS system are noticebly more firmly and relentlessly centered compared to others.

I think you need to keep it simple for now. Direct mode, bypass any Denon processing, check wiring, play familiar tunes from familiar sources, connect the SDA IC. Check everything twice. Relax and listen. Forget all the numbers and just listen, adjust, listen, repair if needed.

Then get an amp (hehe).

I will also add that running music thru stereo direct on my decent Rotel avr (even with a decent separate Rotel amp for the fronts) never sounded as good as when the 2-channel was completely separated from the HT avr. It wasn't until I added a (to me, costly) preamp with HT bypass that I was happy with a merged system (and separate amp for the fronts). This way I get to enjoy the big SDA's for music and HT.

Cheers!

Craig

vcwatkins

Dunno about the 350, but my son has what is considered a Carver pro amp, a PM-1201 (450w @ 8, 600w @ 4 I think). I've tried it with 1C's and CRS's and I really liked it. Not the greatest detail or precision, but it had a wonderful warm tubey muscle to it that I really liked. Paired it respectively with Rotel and Dared pre's and PC and vinyl sources.

Craig

drumminman

If your AVR has pre-outs you could borrow a power amp to see if that makes a difference. This is the first thing I would do.

Has a previous owner been inside those speakers? Can't help but think this is a wiring issue, if not external then internal.

If it was me I'd check:

that all drivers are functioning, and that they are all connected in phase per the wiring diagram found here:

http://www.polkaudio.com/forums/showthread.php?55888-POLK-AUDIO-Speaker-Wiring-Schematics-amp-More-Stereo-Dimensional-Array%28SDA%29

dpowell

Could be a wiring issue, maybe an issue with the tweeters, but my bet is that heiny9 is right in stating that those old worn-out XO's just aren't up to the task anymore. I upgraded from a pair of 1C studios to my current 2.3TL's. The 1C's had fully modded XOs and the 2.3's did not when I first got them. The 2.3's sounded terrible compared to the modded 1C's in so many ways; weak center image, lack of full SDA effect, muddled bass, no pin-point location of instruments/vocals. When I got into them, I found that all of the caps were leaking brown goo. There's no avoiding it, those parts are over 20 years old and just wear out over time. Fortunately, I already knew what modding the 1C's did so it was easy to pull the trigger on modding the 2.3's and now they sing beautifully.

ps. I hate to spend your money for you but that's what others on this forum did for me so now it's my turn to pass on the favor. Others here will shamelessly do the same. :biggrin:

Crashdot

drumminman wrote: »

If your AVR has pre-outs you could borrow a power amp to see if that makes a difference.

The AVR has preamp outs, and also a dedicated preamp mode where the amplifier operation is disabled for cleaner output. Potentially, I could add three amplifiers for the surround speakers and use the unit solely as a preamp/switch for AV sources. The reason I was asking about the QSC and Carver amp, is that these are the only high powered amps that I have access to. I know several people with dedicated amps ranging from 25-200 watts, which won't really help my situation since I have a 300w NAD in the other room.

drumminman wrote: »

Has a previous owner been inside those speakers? Can't help but think this is a wiring issue, if not external then internal.

I highly doubt the previous owner was inside the speakers, but I can check. He was using them just a big speakers I think.

drumminman wrote: »

If it was me I'd check: that all drivers are functioning, and that they are all connected in phase per the wiring diagram found here:

I will check the wiring at some point, but since the SDA effect is working I will be surprised if it has been rewired. I think that the center is weak due to acoustics and lack of compensation for this. When I manually equalize the speakers and add a little bit of high end, the center sounds like it comes out from behind the television. The calibration microphone also reads a significant dropoff in high frequencies with all of my speakers, so maybe it is my room and/or all the studio foam on the walls.

Cheers

Crashdot

dpowell wrote: »

Could be a wiring issue, maybe an issue with the tweeters, but my bet is that heiny9 is right in stating that those old worn-out XO's just aren't up to the task anymore. ps. I hate to spend your money for you but that's what others on this forum did for me so now it's my turn to pass on the favor. Others here will shamelessly do the same. :biggrin:

It is something that I will consider, but I'm about to remodel, and spent the last of my "I really shouldn't be spending any money right now" money on these speakers because there are probably not more than one or two pairs on the island, and I wouldn't expect many opportunities like this. The only other guy that I found that has a pair of large SDAs owns a Hifi store (with things like $50,000 Wilson Audio speakers), and has the speakers in storage. When I asked how much he wanted for the SDAs, he said "I won't sell those".

I can't imagine how much these must cost to upgrade, considering how much was spent on my RTA12s, and therefore I would probably have to go with very modest components which may not offer as much benefit.

Cheers

Crashdot

F1nut wrote: »

Re: spikes
They make the speakers sound better.

What can I use on or as replacement for the leveling feet, on a hard floor? I am replacing the carpet with flooring.

Thanks

F1nut

Spikes with floor discs.

dpowell

If you do them yourself and buy the caps when they have a sale, you can upgrade those XO's for around $225. Add $100 if you get gimpod's replacement boards (which are very nice to work with). No rush though. Enjoy them for now and get used to their sound, then you'll really appreciate the upgrade once you have the funds.

drumminman

dpowell wrote: »

If you do them yourself and buy the caps when they have a sale, you can upgrade those XO's for around $225. Add $100 if you get gimpod's replacement boards (which are very nice to work with). No rush though. Enjoy them for now and get used to their sound, then you'll really appreciate the upgrade once you have the funds.

+1 - the money for new caps and resistors shouldn't be too bad on your new speaks. And the improvement will be dramatic!

If you modded the RTA 12X's and did both upper and lower Xovers in each cabinet with quality parts, you spent some coin! Those have some of the most parts intensive, complicated Xovers around. The 2.3 Xover is much simpler.

My 2.3TL's had been gone into by a previous owner with mixed success. I was scratching my head at some of what they did. For example he changed the wire connections to the 16mH inductor, and when I gave them a slight tug to check how solid they were, they came off in my hand.

Doesn't take only a big problem - lots of little screw ups can have an effect on the sound.