female needs expert advice


bough a new pair of mirage om 5 loud speakers.Iam biamping them with 2 classe 70 power amps. these speakers have 2 250wattamps built into them for the bass.I have 2 pairs of tara labs speakers cables about 8 years old tara quatums reference.what do you think would cable for them. I want something that is fast being in boogie factor @transparent don,t we all.One more question ,Iwas horizontally biamping these untill iwas talking to the maker of these speaker who told me to vertically biamp.To do this he said to take the two + and two- speaker spads of the rt speaker and put them on the rt channel of one amp and use the rt channel of amp input to rt channel of preamp do the same with left speaker and other amp . i feel that using one channel of eash amp is a waste any other ideas is welcome I don,t want to buy new amps these to me sound good but i just hate the waste the reason for doing it this way the top two things on speaker are for the mids and highs the other 2 are just to send a signal to the built in power amps fun hey? so help me guys thanks.
tarbishaw

Showing 3 responses by sean

My experience with the Classe' 70's ( in specific ) are that they are bright and lean sounding. With that in mind, i think that the Tara's would be a relatively good match. If you want something that sounds very fast and clear, try some Nordost. It does not have the mid-bass warmth that the Tara offers. It would therefore lack "prat" in some systems, but it is extremely quick without being "edgy" or "sibilant" sounding.

As to using one channel of each amp without bridging, that is a "bunk" suggestion. Even if it came from the speaker manufacturer himself. Maybe if you had a little "weasel" of an amp with no power supply, but you don't. This was a common trick with the old Quad 405's. It became so common, that Quad even started making the amps with only one channel in the same chassis, but kept the power supply section that was designed for both channels in them. This was their idea of a "monoblock" and it did work much better.

Since the Classe' amps have got good sized supplies in them, i would not worry about that. This is evidenced by their sizable increase in power output as impedance is lowered and their reserve i.e. dynamic headroom rating. Besides that, you are only using them for the mids and treble, where power and current are not as big of a factor. That is, in comparison to if you were trying to power large woofers with a powerful motor structure.

As to Jeff's comments about bridging the amp ( tying the two channels into one bigger channel), voltage is increased and the current remains the same that you would have for one channel. Not only do some amps sound worse when bridged ( primarily due to the use of unmatched driver and output devices from channel to channel ), the bass can get soggier if running full range. If the amplifer actually improves in performance and sonics when bridged, that tells me that the amp was not designed properly to begin with. My guess is that the rail voltages that feed the output devices are too low and the circuit is more comfortable with the higher voltages that bridging produces. Like anything else, output semiconductors and circuits have "sweet spots" where they run best at. Part of building and designing an amp from scratch should take that variable into consideration.

While horizontal bi-amping does have its benefits ( especially if running full range ), i would suggest going vertical in your case. This will isolate the stereo signals and confine each channel to one amp each. This should minimize crosstalk and possibly improve your stereo imaging. If you were running the amps full range i.e. driving the woofers with one channel and mids / highs with the other, i would suggest horizontal.

Keep in mind that there are a LOT of different opinions and variables that apply to every situation. The best way to find out is to experiment for yourself and see what you like best. That way you'll know, see and hear the differences first hand and can chime in with your "experience" and "opinion" as the opportunities arise. Sean
>
I don't care WHO the guy is, who he works for, how many tests he's done, etc... If you can't tell the difference between some very specific speaker cables in a system, something is VERY wrong. I am not talking about "stupid" test conditions where people are substituting 30 gauge wire for 12 gauge wire in 25' runs either.

Keep in mind that ALL of the testing that Gordon Gow, Larry Greenhill, Edgar Villchur, etc.. did, they compared ZIP CORD to ZIP CORD. All they changed was the actual gauge used, not any major electrical or geometrical characteristics.

I found this "excerpt" EXTREMELY interesting. "Journal of the Audio Engineering Society by Lipshitz and Vanderkooy titled "The Great Debate: Subjective Evaluation" Volume 29, No. 7/8 July/August. They estimated that when level differences occurred over a wide band, they were detectable down to 0.2 dB." Roger then tries to "discredit" these findings by saying that the authors / conductors of the tests somewhat "negated" their findings via a PHONE CONVERSATION !!!! Why weren't their findings directly challenged in a rebuttal JAES paper or "amended" by the authors if this were true ??? What kind of CRAP is that ?????

Keep in mind that, EVEN if Lipshitz and Vanderkooy DID state this, they specifically mentioned that the differences at extreme high frequencies might be negated due to hearing loss as one ages or their hearing deteriorates. They did not state that the differences would not be noticeable in the midrange, where our ears are most sensitive.

The differences in speakers / speaker cables / amplifiers respond as a WHOLE. That means that some systems will be more sensitive to changes than others. I do agree that gauge WILL affect sonics, but not only in low frequency response that requires greater current. High frequency response and overall tonal balance IS affected. In some severely reactive cases, different wires can literally "make" or "break" a system due to "buffering" or adding reactance to the load that the amplifier sees.

Nelson Pass documents the various levels of loading that occur when ONLY speaker cables are changed within a specific system. There are VERY obvious differences in rise times, overshoot, ringing, etc... amongst all of the cables tested. Now mate some of those cables with various types of loads ( big impedance swings, very low impedance loads, highly reactive loads, loads that vary reactance with frequency, etc ), with different amplifier output designs, and you can see how EACH system could produce enough variables to make ANY "set in stone" claims about audibility / lack of audibility completely "assinine". Anybody that thinks that they know all of the answers for every situation known ( or not known ) to man is pretty narrow-minded and just flat out "dumb".

Keep in mind that i am NOT a proponent of "MEGA dollar wires" nor am i affiliated with any wire / cable manufacturer. I do feel that wires can and do make a difference though. I base this on testing that i and others have shared with common responses.

As someone else stated, buy what makes the biggest difference to YOUR ears. Then have your cables "burned in" for best results : ) Sean
>
Tarbishaw, everyone hears things differently, has different systems and has different personal preferences. As such, take ALL recommendations or comments with a grain of salt. This includes mine too. Listen for yourself, try to absorb as many thoughts and opinions as you can and enjoy the journey.

Sarah, i GREATLY envy you. That sounds like it has the makings of one HELLUVA "hoe-down" to me. Out of curiosity, do you listen to any "harder" music at all ? If so, i think i've got some discs that you might like.

Francisco, drop me an email when you get a chance. I have not received any emails from you in a while, so there is some type of a "goof-up" taking place somewhere in "cyberland". Sean
>