McIntosh Set-up Support Please

[Z4J]

Hello. Hoping some of you more seasoned audiophiles can help me with direction.
Situation- I currently have a MA6300 with Klipsch RF-7 II's. I like the sound, but very underpowered for mids and lows. I have a MC402 on the way (my plan is to purchase a pre-amp someday after saving for separates). Until then I'm planning to use the MA6300 as the pre-amp. A few questions from this set-up please-

1) The 6300 has a 1V preamp main output. The 402 is set up for 2V input (unbalanced). Should I expect the 402 wattage output to be roughly half of the 400 watts due to the 1V output?

2) Should I expect the preamp of say a C47 to sound much better than the MA6300 when using the 402? Essentially is it worth the trouble/additional cost?

Any other input you can give for this set-up would be greatly appreciated.

Also, what is a great pre-amp for the 402?

Thank you all very much and thanks for the time.

 

[c_dk]

First off, welcome to Ak.

1) the 1 volt reference is a basic industry reference to publish with things like frequency response deviation or signal to noise. I am quite positive the MA 6300 preamp section will put out in excess of 5 volts if bench tested. Every Mac I have ever tested over 40 years has.

2) my consideration is what you find lacking in the sound now. It would seem that you are finding a flaw in the bass response from your statement which I would guess is either a speaker issue or room placement issue.

It has been a decade since I had any involvement with Klipsch speakers and from listening to potential owners auditioning statements there was a lot of love them or hate them opinion.

I would seriously doubt that the fault you alude to is caused by the amp and while the 402 is a major amp upgrade from the 6300 I would not bet on it solving your speaker issues.

 

[4-2-7]

Actually I'd put money on the 402 will change the character of the speakers giving you a much better bass response and recovery speed. I think you'll hear those speakers as never before even at low volumes. You will also have the head room for the transient peaks in the music so really overall performance in all frequencies should be a gain in SQ

 

[c_dk]

Hopefully the OP will let us know once his 402 arrives. I would play with the speaker room placement, especially distance from the back wall while awaiting the amp.

 

[Chubba]

If money was no object I would replace my RF-7II with some high end Tannoy or JBL.I really like the sound at any volume that I get now with my MC-252 and my Sonic Frontiers preamp.The MC-402 will be great with those speakers.I have much better sources than in my sig such as tt/cart,dat deck,reel to reel and cd.I am very content with those speakers.Cheers

 

[Z4J]

All. Thank you for the welcome and such quick and excellent insight. Please keep the comments coming as it's a great help to me.
My gatherings so far-
-My 1V may not be an issue and is possibly much high (I certainly hope so).
-Hit or miss with the 402, but it should power the RFII's better. Klipsch told me the II's need more that what the 6300 can give. Speakers rated at 250W/1000 peak.

So dont rush to a pre-amp.
Adjust speaker placement.
Report back on my stumbles and finding

You all rock! Thank you.

 

[c_dk]

Have to recheck my rule of thumb math but with 64 watts these speakers should be able to approach the conservative threshold of pain level of 120 dB, so I doubt the integrated is lacking in any way to power these speakers.

I found these speakers to be engineered for popular "mid fi sound" and therefore either a easy get out of the way sale or a completely rejected audition.

 

[isotopesope]

Klipsch told me the II's need more that what the 6300 can give. Speakers rated at 250W/1000 peak.

wow, they're claiming 100 watts per channel is lacking for speakers with 102dB efficiency?

Klipsch fan boy here.... my Forte III's (99dB efficiency) do quite well with 75 watts. i too wonder if speaker placement and room treatment could make some improvements for your setup.

where in the room are the speakers placed? i have smaller Kilpsch RP series in my 5 channel surround setup... i find my rear ported RP-250F's need to be pulled away from the wall at least 18"-24" to get decent bass response. i ran these towers in my 2 channel setup, before building the 5 channel system.

 

[62caddy]

With a speaker sensitivity of 102 dB @ 1w @ 1m, it's highly unlikely lack of power is the issue.

Try moving the speakers closer to walls or in room corners.

 

[Z4J]

Will do. Thank you. Yes...I was told to go at least 250W to properly push the lows. Don't get me wrong, they're plenty loud, but no "guts." The woofers move very little. The yeild from speakers placement was minor. More to come--thanks everyone.

 

[62caddy]

Will do. Thank you. Yes...I was told to go at least 250W to properly push the lows. Don't get me wrong, they're plenty loud, but no "guts." The woofers move very little. The yeild from speakers placement was minor. More to come--thanks everyone.

Chances are you are not using 1 watt for most normal listening with speakers of that sensitivity. Paul Klipsch himself famously said, "All the world needs is a good 5 watt amplifier." The use of 5 - 10 watt SET amplifiers is not uncommon with speakers of 100 dB+ sensitivity. High sensitivity speakers are inherently limited in deep LF response.

It sounds to me that you simply don't care for the LF performance of these speakers. No amplifier is going to change that.

 

[TSmith8605]

Did you double check your speaker connections to make sure they're in phase - meaning the + speaker terminal on the amplifier is connected to the + terminal on the speakers for both speakers. If one of these is backwards, bass response will be partially cancelled and significantly attenuated.

Crown has a website with a tool that can help you determine required amplifier power given listener distance from speakers, the speakers sensitivity and desired listening levels (in dB). This is not a precise tool since it assumes only one speaker - and things will be about 3 dB louder with 2 speakers (stereo) - and it does not account for room acoustics reflecting sound back at you (as opposed to listening outside in the open), but still kinda fun to play with and will get you a ballpark idea of how you're doing.

Using this tool with your 101-dB-sensitivity Klipsch speakers, with the listener at 12 feet, with 6 dB of spare amp power for peaks, your MA6300 (100 W) amp should develop 104 dB (actually 107 in stereo and a bit more depending on your room).

The 400 W MC 402 will get you up to 110 dB (actually 113 in stereo and a bit more depending on your room).

The Klipsch numbers of 250 W with 1000W peak (mean 6 dB headroom), will get you about 108 dB (actually 111 in stereo and a bit more depending on your room).

Another tool, if you have a smart phone, would be a free sound pressure meter app that you can use in your listening chair (also a rough but instructive tool). At my couch, I get roughly 90 to 93 dB levels when I want it loud and find 80 to 85 dB to be a pretty satisfying listening level. Just under 80 dB can be great for critical listening.

I took my meter (phone) to a jazz club and, sitting about 10 feet away, measured a live drum kit at around 100+ dB. In that case, I reached for some hearing protection and / or moved back a bit. (The drummer was also wearing hearing protection.)

To summarize, with your Klipsch at 12 feet range with 6 dB of amplifier overhead:

Desired level ----> Power Needed
120 dB -------------> 2,000 W
113 dB --------------> 400 W (MC402)
111 dB --------------> 250 W (Klipsch recommended Pwr)
107 dB --------------> 100 W (MA6300)
95 dB ----------------> 6 W (Any <-- decently loud rock and roll level)
85 dB ----------------> 1 W (Any <-- decently satisfying listening level)

According to the website linked below, if you listen for more than about 4 minutes to 107 dB (i.e. from you MA6300), you will sustain permanent hearing loss. The MC402 will get you there in about 1 minute.

Question: How long can a person endure a certain noise level before hearing impairment occurs?

Having said all that, if all things are working properly, I think the MC402 should sound better than the MA6300.

 

[Z4J]

Great information. Thank you all very much. I was able to talk to Klipsch once more. Excellent customer service and input on my situation. Will report back on 100w vs. 400w by the weeks end.
Tsmith....excellent stuff. Thank you for taking the time.

 

[62caddy]

In the one setup I have, the speakers are ~ 13 feet away from the listening position.

With a pair of 103 dB Heathkit/Altec speakers that I owned, 3 wpc would have me running out of the room with hands held over ears and those valiant officials of the law would be summoned in short order. That said, it is inconceivable to me that an MA6300 wouldn't be up to the task of driving a pair of 102 dB speakers at any reasonable listening distance. I guess a few here listen at far higher levels than my ears could ever tolerate.

 

[damacman]

In the one setup I have, the speakers are ~ 13 feet away from the listening position.

With a pair of 103 dB Heathkit/Altec speakers that I owned, 3 wpc would have me running out of the room with hands held over ears and those valiant officials of the law would be summoned in short order. That said, it is inconceivable to me that an MA6300 wouldn't be up to the task of driving a pair of 102 dB speakers at any reasonable listening distance. I guess a few here listen at far higher levels than my ears could ever tolerate.

. . . valiant officials of the law . . . ? Did you age 50 years since I seen ya' caddy? LOL . . .

 

[4-2-7]

Will do. Thank you. Yes...I was told to go at least 250W to properly push the lows. Don't get me wrong, they're plenty loud, but no "guts.

As I said below

Actually I'd put money on the 402 will change the character of the speakers giving you a much better bass response and recovery speed. I think you'll hear those speakers as never before even at low volumes. You will also have the head room for the transient peaks in the music so really overall performance in all frequencies should be a gain in SQ

Only one speaker I ever had that didn't respond this way^^^ when the amp over powered the speaker, that is my IMF RSPM Mk.

 

[Chubba]

I am very surprised in a way that I hear sounds as well as I do let alone at all.I have always had loud jobs but protected my ears.Music at home and concerts no.Lately I started to hear the details in recordings at the 2.5 w level often for last year and enjoy it The Paradigm 90.p are set up as sub woofers.Man do I like to turn it up.I would think your Mac would play well wth these speakers.Does it have tone controls?

 

[Z4J]

I won't even pretend to know 1% of what you all know, but my money is with 4-2-7's money. We'll see if more wattage will help the 4 10" woofers fill and allow each speaker to keep pace with anything thrown at them. Chubba...no tone controls on the entry level MA6300 that I'll be using for the pre-amp until I can save more for C52, C70 C1100 (one can dream). Any McIntosh preamp recommendations? Used is fine by me.... Thanks again everyone.

 

[twiiii]

You are not really going to notice big difference between amps unless the 6300 has other problems. My son has a pair RF and they are designed to be used with a sub woofer not stand alone stereo speakers. I would be looking to change speakers not amps. If you want speakers with a little better bass and lower midrange from Klipsch, I would be looking at Cornwalls. As far as pre-amps are concerned I would want. pre amp with Graphic controls so you can boost the very low frequencies and the low mids with out influencing the rest of the spectrum as you would with conventional bass tone controls. I know that leaves out tubes but what. can I say. I will admit amps with Quad balanced design are mellower in some respects than direct coupled amps. But that because of greater signal to noise and lower distortions . With the klipsch speakers I doubt you will be using much more than 40 watts for, peaks so using the 6300 pre-amp section should not be an issue. If you wish to keep your RF 7's and decide you need subs. Make sure you use two subs, one for each channel and that the cubic displacement volume potential of the sub woofer movement is 4 times that of the cones of each RF 7. If you cross at 80 Hz and the subs are designed to reach 20 HZ. I would want subs with built in voicing capabilities to take care of room anomalies. Finding efficient loud speakers to day without a colored sound is quite difficult, but can be done.

We use to have parties in college with two Cornwalls and a 2105 with a C-28, and we could make people knees weak and almost peal off the wall paper. So Klipsch speakers can do the job, just make sure you pick the right ones and install them properly in your listening space. Remember Klipsch is about dynamics first, lower distortion second and bandwidth 3rd.

Personally I would prefer some older Mac speakers or certain specific JBL speakers. I am not a point source speaker fan. But we are talking money. Nothing thats good is cheap now days unless you buy pre-owned and there are many challenges to face taking that road unless you find honest dealers with a proven record...

 

[62caddy]

I couldn't agree more with @twiiii : If the OP is serious about improving LF response of the system, he'd be far better off investing in a pair of subwoofers rather than throwing money in into higher power amplification. But his mind seems to be made up where the problem lies so there is nothing further to be said.

I wish the OP the best of luck with his upgrades.