Upgrade my amp again

Mcanaday - My suggestion regarding the amplifier was specific to your speaker and your issues with the soft bottom end. IMO, an amplifier that has the ability to double the amperage when a speaker’s impedance halves at some frequency is desirable. It will work with a wider variety of speakers. A speaker that presents a relatively flat 8 ohm impedance at all frequencies will not require a amplifier with that quality. Your speakers are rated at 6 ohms that drop into the 3s. The power rating of most amplifiers assume an 8 ohm load. So that’s why I got into the impedance thing with you. Your speakers like a bit of current.

I haven’t heard the signature version of the Model One but understand that it’s a significant advance on what I already considered a terrific all around speaker that plays bigger than its size. I’ve heard the Model One’s in similarly sized rooms with higher ceilings and thought they were sufficient. You might want a sub if you really like to rock. I recall liking them with McCormack and Bryston amps, but think that any good amplifier that meets their power requirements will do. I’m not suggesting that you buy new speakers if you like yours, I was just sharing my thoughts. Only you can determine if they are overloading your space.

Re:"It won't matter what speaker you put in the room.”

Balderdash!

Mcanaday,

I didn't realize you were having trouble with the other thread. Were you able to ready my first post? If not, I'll re-post it in this one. If you were able to read it, I still think its very relevant to your situation. The other posters all offer very good advice, but you still have to choose components that you like the sound of. Also, I'm not too clear as to what you mean when your say the sound is muddy. Is it a distortion issue like something is actually breaking up, or something else?

While there are some 35 watt amps that can drive your speakers well, I don't think the 5004 is one of them. I think the T6 is a much better speaker than the 5004 is an amp, though it is good value for the price.

Hi Bob, I’m no scientist but I have no doubt that you and Dr. Toole are correct about energizing room modes. That said, I don’t believe that’s the only element to consider when trying to choose the right size speaker for a room. I say that because I’ve been in rooms where, IMO, the speakers just sounded too darn big for the room.

With a 6.5 foot ceiling, the cubic volume of his room is roughly equivalent to a 10x11 room with a more typical 9ft ceiling. I haven’t heard his speakers, so all I can do is offer observations based on my personal preferences applied to what he’s telling me. And it is more likely than not that I would personally prefer a smaller speaker with fewer drivers in his room. I will allow that if I sat down to listen in his room, I could be proved wrong.

Interesting discussion, with some good points being made on all sides, IMO.

I would think that the major factor, or at least a major factor, that would contribute to a perception of a speaker being too large for a room would relate to proper blending of the sounds coming from the various drivers.

Obviously if there are numerous drivers spread out over a large baffle the minimum listening distance that will allow proper blending of the sounds coming from those drivers will be greater than in the case of, for example, a small two-way. And listening from that minimum distance may necessitate placing the speakers too close to the wall behind them, and/or placing the listener too close to the wall behind him or her. Or it may not be possible at all.

Also, increasing the listening distance in a small room will increase the significance, and the potential adverse effects, of reflections from the side wall.

One adverse effect that all of the foregoing can result in is comb filtering, which will tend to be perceived as a general loss of clarity.

Tom (Phaelon), one unrelated factual correction: The OP is a "she," not a "he." :-)

Best regards,
-- Al

I agree, interesting discussion with different opinions, so here’s mine.

No doubt a different speaker could be better suited for the room, however I think you definitely need more power on the current speaker.

they sound great with jazz or acoustic. With rock, they can sound a bit muddy

Since you said they sound great on jazz or acoustic implies the speakers are working OK in the room. Rock music is generally played somewhat louder than the others stated due to the tendency of “Let’s rock, crank it up!”, therefore requiring more power from the amp. The Marantz pm5004 is a good value, but with its rated power of 35w @ 8 ohms, and 45w @ 4 ohms, should be used on a less demanding speaker. Reviews and measurements on the PSB T6 indicate it should be used with a substantial 4 ohm rated amp. Also, considering the speakers’ measured sensitivity, average listening distance, and moderately loud listening volume for rock, it’s easy for me to see that the power requirement could exceed the Marantz pm5004.

And is the general issue about right amp for a speaker about the ratio (ie double the watts at 4 ohms) or is there an absolute number? Ie: ideally you would like 80 watts for a 4 ohm speaker?

Basic speaker/amp matching is generally done using the speakers’ sensitivity. Take a look here,

http://www.diyaudio.com/wiki/Loudness_and_Speaker_Sensitivity

This is all based on a 1 meter distance, and since you are probably further away, the reduction of perceived loudness at greater distances must be considered. The approximate reduction will be, 2M – 6db, 3M – 9.5db, 4M – 12db, 5M – 14db, 6M – 15.5db. Obviously, the greatest effect is the first 4 meters.

A 4 ohm speaker is more demanding than an 8 ohm. The amp should be rated for 4 ohm, or even better, rated for 2 ohm. It is definitely a big plus for the amp to double its power into a 4 ohm load, but not absolutely necessary, although you would want to see a substantial increase, much more than the 30% increase of the pm5004.

In speaker/amp matching, it is always better to err on the side of too much power than too little. With too little power, the desired sound cannot be achieved, and there is a greater risk of damage to the speaker, amp, or both. Since a double of power is only a 3db increase, I believe I would be looking at amps in the 100w range and above.

As Captain Kirk said, “Scotty, we need more power!”
.

Point taken Bob, and thanks for stepping in Al. I’ll be the first to admit that technically speaking, I have a lot to learn. I hear what I hear but I don’t always know why I’m hearing it. I would actually like to be wrong on this issue because I've been operating under the premise that many of the efficient speakers that I am interested in are too big for my room. But I don’t know how else to explain the sensation that many of the smaller volume rooms, with big speakers, that I’ve been in were just overwhelming to me.

"I haven’t heard his speakers”

Mcanaday - Beg your pardon ma’am; I shoudn’t have assumed.

I always appreciate your contributions Bob... they're well thought out and I’ve learned by them.

Hi all-
As always, I learn a lot from the conversation here and am grateful to all who weighed in. (I have only been slow to respond because I've been stuck cleaning the basement all weekend. It's clean now!) To respond to some of what has been raised here: it is quite possible that these speakers are all wrong for the room. I am enjoying them, but I am new to this. It's possible I have no idea how good the really good stuff can sound. The limits of the room (ie ceiling height) are what they are, though, and I am always going to have to live with that. It does seem like whether or not a mini monitor would be better for the space, there seems to be consensus that a better amp wouldn't be a bad idea. I'll probably start there, and then think about changing the speaker or adding a sub after that (depending on how the new amp sounds). A few other comments. Thanks, Bob, for your advice. I will read Dr. Toole! And thanks too, Phaelon. No worries at all about the gender mix up (I'm assuming that 95% of the folks who post on these sites are guys, so it was a pretty fair assumption!) To Zd542...the issue was not breaking up or distortion. Only that rock doesn't sound crisp, clean, or detailed on this system. As for what music I like: jazz, blues, country, rock, pop, etc. To TLS49 or anyone else, I am a bit confused about which number matters when deciding if an amp has enough power for my speaker. You have recommended an amp that is above 100 wpc. So to take an example, the Musical Fidelity M3i is 76 wpc, but that is 76 into 8 ohms and 137 into 4 ohms. My assumption is that this amp would be powerful enough (because of the 137 number.) Is this correct? Thanks again, guys, for all the good advice. I am having a lot of fun trying to figure this all out. Lots to learn! cheers, Margot

Margot - One more thought. What kind of floor do you have? If speakers aren't mated to the floor properly, that can definitely contribute to bass issues which might seem to “muddy” the sound.

the Musical Fidelity M3i is 76 wpc, but that is 76 into 8 ohms and 137 into 4 ohms. My assumption is that this amp would be powerful enough (because of the 137 number.) Is this correct?

Margot, the MF M3i would definitely be much better than the Marantz pm5004, and it may be powerful enough with a 3db increase at 8 ohms and approximately a 4.5db increase at 4 ohms, however the required power is determined by a relationship between the peaks of listening volume, listening distance, and speaker sensitivity. As far as the 8 or 4 ohm rating, when a manufacturer recommends a power rating for a speaker, this is generally the 8 ohm rating. The 4 ohm rating for an amp helps determine how substantial the power supply is, and its ability to deliver the power into a demanding load the speaker may present as music is played.

Take a look at the owners’ manual for the PSB T6 here; section V- D. (Recommended Power),

http://www.psbspeakers.com/content/110616100531-PSB_OM-200ImageImagine_English_Manual.pdf

The manual even recommends a minimum of 50wpc for room filling volume. The MF M3i may be adequate for your needs, but the only way to know is try it, or get a SPL meter as Bob stated, measure maximum peaks in various music, and do the calculations. For more power in the price range you stated, the Creek Evolution 5350 and the NAD C 375BEE are good choices. Also, with more power, The Peachtree Nova125 would offer two choices in the character of sound by switching its’ tube buffer in and out. It also has digital inputs, but only one analog input.

Phaelon has brought up a very good point about how the speakers are coupled to the floor. Again, look at the owners’ manual in section I-B-2. (Molded Feet and Stabilizers). Are you using either the spikes for carpet, or rubber feet for a hardwood floor?

Hi Bob, Phaelon, and Tls49,
Thanks again for all your advice. Lots to consider here. As for floor treatment, I think I am probably okay. I have the speaker spikes in a berber carpet. That wouldn't pose an issue would it? And I will look into the meter and do some measurements. with thanks! Margot

I hate to add confusion, but the wattage ratings are only part of the story. I recently replaced a 150 watt amp with a different 150 amp (inefficient speakers in a bigger room). The difference was immense! The power delivery, control, and even volume was hugely increased. My point is only that the watt-per-channel number doesn't tell the whole story on whether an amp can drive your speakers properly, and the speakers MAY only be highlighting the amp deficiencies(?)