Just a bit to bright

You might consider something with tubes. Transistors often tend to have a coloration of brightness, which has nothing to do with bandwidth.

A slight brightness can be the result of your speaker positioning, overly reflective room surfaces, powerline distortions/grounding issues, source material, non-optimal cabling, etc. Since your loudspeakers are DIY you could pad down the treble via crossover mods. But before changing anything I suggest you try the treble control on the NAD.

What is your room like... are u listening nearfied or not, any room treatments to absorb standing waves?

Turn the NAD off!

Atmashpere, Onhwy61, Lowrider67 & Viridian.... Thank you for the comments and suggestions. Points well taken, I have quite a few things to experiment with before jumping into switching amps and preamps. Even though I did build my speakers I wouldn't have a clue about crossover mods. I just built what was specified. So, I'll try some of the simple more "obvious" suggestions and go from there. Thanks again!

I am still curious on one point... When considering amps and preamps, does one have more impact than the other on the sound we hear? Or are they equally responsible for the end result?

Jeff

You have some good suggestions here - I would add that if you don't want to consider tubes, try a Naim integrated. My brother went from an NAD to a Naim in his system, and loved it. And there is also that famous thread on another site where a whole bunch of tube guys were asked the question - if a gun was held to your head and you had to buy a solid state amp, which would you choose? The answer was overwhelmingly Naim. It sounds great in my brother's system, which is in some respects quite similar to yours.

I have 2 NAD integrated, the C326BEE and the C372. The older 372(7 years or so) is warmer sounding than the 326, yet I wouldn't call the 326 bright. I have Paradigm S6 speakers with forward sounding tweeters that make some amps sound brighter.

I had this struggle that you are having as well. Your speakers with the ribbon tweeter are going to be brighter sounding, and with your preferences you are going to need to compensate for this. Something that helped me is better cables. What kind of speaker cables do you have? If it's just basic stranded copper 10 or 12 gauge, I'd suggest Audioquest Type 4, you can buy it in bulk per foot. It really brought more focus and clarity to the sound, something I was really surprised about.

Rather than trade up components as I did several times, your issue might be easier to fix. The NAD isn't bright, neither is the Onkyo. Just a thought.

03-10-14: Jfmerk
I am still curious on one point... When considering amps and preamps, does one have more impact than the other on the sound we hear? Or are they equally responsible for the end result?

I feel that the preamp has more affect on the sound that we hear than the amplifier, but I'm sure others will disagree. You could always try a tube integrated amp in place of the NAD, in which case you could get the richer tube sound, as Atmasphere suggests, and not worry about the which component does what conundrum of preamp or amp.

One further thought. The speakers in this set up could be a difficult load. Any idea what the ohm rating is and if it dips lower at certain frequencies? It could be a tough load for a near entry level integrated amp. If that's the case, at higher volume levels it could produce a harsher sound.

A Tube integrated would certainly be warmer too.

try some solid core 12 gauge mains wire from
Home Depot for the speakers. And dump any
cheapo interconnects.

I am still curious on one point... When considering amps and preamps, does one have more impact than the other on the sound we hear? Or are they equally responsible for the end result?

I also believe that the preamp highly affects the color or timbre of the system.

BUT, as Runnin points out, it is the amp that drives the speakers. The first part of putting together a system is matching the amp to the speaker, and since your spkrs have a low impedance, you may need a more powerful amp.

The resistance curve found on the left side shows that impedance drops to 3 ohms at 100 Hz and approx. 4 ohms from 1K to 4khz.
http://speakerdesignworks.com/MiniStatements.html

The specs on your amp show:
- 2 x 50W Continuous Power into 4 ohms and 8 ohms
- 100W, 150W, 200W IHF Dynamic power into 8, 4 and 2 ohms, respectively

I am not familiar with the design of the NAD, but it looks like it may possibly be enough power, but borderline IMO.

What do the other NAD owners think?

You need to learn right away, to avoid bleeding money needlessly for your audio career, to fix the problem where it exists instead of using band-aids for flawed product. You can never solve the flaws in products with purchases of components that have their own severe colorations in the other directions. These are all distortions and they don't cancel out, they add up.

Not saying your speakers are way off neutral, but you need to know before you start building a mix and match system. Amateurs and experimenters will say that "it's all mix and match" but only to smaller degrees of you pick excellent products.

Borrow other speakers, just to see if indeed it is your speakers. Take yours to other places to plug them into other components to see if brightness follows you speakers or if it does not. Know exactly what you have before you start buying.

The above is coming from someone who has spent his life selling components to mostly audiophiles, and the occasional music lover (they are not the same), but hate taking money unless true improvements are the result. I've seen tons of money thrown out because folks have been attached to a flawed component. In the end, after spending tons of money, they then end up replacing the flawed component anyway!

Maybe your speakers are the problem. Maybe they are not. Find out what the problem is before buying anything.

I'd remove the NAD 326 from the mix. The right amp will make a world of difference. I'm so impressed by my most recent purchase of a bipolar Adcom GFA-5002. Heck of an amp! The 5XX series of older Adcom amps were bipolar as well as I have read. Adcom still makes new Bipolar amps. You should be able to resolve your very slight brightness issue w/a different amp/pre-amp/int. amp. Good Luck!

Since you built the speakers I would take the easy and least expensive step. If your tweeter is too hot, then replace the capacitor with a nice PIO type that will do wonders. I suggest Jupiter HT Flat Stacked. If you also have a cheap sand cast resistor, replace it with a Mills MRA.

This will do the trick. It will make you smile!

I would be happy to help if you need direction. This will impact your system more than wire or an amp change and allow you to keep your speakers.

It will not require you to buy, sell and ship gear.

Your speaker uses Dayton caps and resistors....oh yes the mod I mentioned above will do wonders!

Very good advice above, particularly from Kiddman nad Grannyring. Given that the speaker is something of an unknown element, it is a prime suspect. Also, different model speakers vary much more in sonic characteristic than do any electronic component. You should check it out by making direct comparisons with other speakers. If the problem IS with the speaker you should really consider dealing with the problem by either replacing the speaker or modifying the speaker before considering chasing compensating with other component choices.

Any extreme effort to compensate for a fundamental imbalance of flaw in one component by choice of other components will be a big waste of money and is not likely to work. Components may subtlely complement each other, but, they cannot correct for weaknesses of others.

It is understandable that you have a fondness for the speaker you constructed. That is why Grannyring's suggested crossover upgrade is a good first attempt at curing a problem if it turns out that the speaker is the primary source of the problem. This is a not too terribly expensive approach and you can go back to the original components if the modification makes matters worse.

Before doing anything at all that involves spending money, try changing speaker placement or moving the listening chair. Tonal balance can be changed quite radically by placement changes and there are infinite choices one can experiment with. With most speakers, the easiest way to change upper frequency balance is to alter toe-in of the speaker and the backwards tilt of the speaker. You could also try some simple room treatments to tame excess reflection of higher frequencies (e.g., put up tapestries on the walls).

Good luck.

Sometimes it's just the recording.

"Sometimes it's just the recording."

Yes indeed.

IT's useful to get a metric/rough idea on what % of recordings sound bright, and which ones are brightest.

Ideally only a minority should come across as bright. Then you go from there to try and make the % smaller if needed or not.

If its a small % that come across as bright, that may be normal. If many, a majority, or all, then there is clear room for improvement most likely.

Lots of poor to average recordings and that cannot be avoided. The mod with the Jupiter caps will also help those. Yes, play with toe-in as well as sound absorption panels at the first reflection point.

Thank you for all the replies!
Lots of great food for thought which is exactly what I was hoping to find here.....
A couple small bits of information:
My speaker cables are 10 gauge, 462 strand OFC
Interconnects are AudioQuest G-Snake
My speaker sensitivity runs about 85 dB (@2.83V), if you adjust for a 4 ohm load they're around 83dB (@2V)... Based on my test results using the 1 watt, 1 meter distance standard.

I have a few friends that would likely allow me to try an amp or place my speakers into their system and look for the brightness to remain or disappear or...

With regard to toe-in, my speakers are designed with a mid transmission line/pass through.... The mid-range driver has an open tunnel to the back of the cabinet. They should be placed 18" inches from the back wall and with straight ahead positioning. They really do offer great imaging with vocals in particular.

I'm really intrigued with the idea of swapping out some of the Dayton components! I built the crossover boards in a way that provides easy access and removal, so Grannyring, I may take you up on your offer of help.

I've also been exploring an amp by Class D Audio. Reviews state it has a very warm tube like sound. With 250W @ 4 ohms I suspect it would drive my speakers well. But... I won't be pulling the trigger anytime soon. I've got homework to do.

Patience. I've put my wallet away and will continue exploring the simple and inexpensive adjustments.

Thanks everyone!

Jeff

They should be placed 18" inches from the back wall and with straight ahead positioning

This statement may give a clue to the problem here. So whether you have a 10 foot long room or a 100 foot long room, they should always be placed 18" from the front wall? I don't think so! The amp might be a problem but not the first problem you should deal with.

Have you experimented with the difference between bi-polar outputs vs. mosfet outputs? I mean even to audition? Your NAD will never satisfy you. It's simply not high enough caliber given your op. There is a marked difference in general between the two. Mosfets are softer on the top end, however, really good bi-polars make no apologies. They are faster. But I'm convinced you really just want something better than what you've got. You really are still at square one in terms of what topology pleases you. An excellent bi-polar example would be the Harman Kardon Citation 16. A legendary amp which is imo second to not many sota amps even today. It came out around 1980. A competitive mosfet amp would be an Acoustat TNT200 or 120. Same era. Both are still highly sought after. The newest HK offering apparently has the same basic circuit as the 16 which is in itself revealing.

Great advise from Kiddman. I often wish I had learned that lesson much earlier in my "audio career".

You can never solve the flaws in products with purchases of components that have their own severe colorations in the other directions. These are all distortions and they don't cancel out, they add up.

Yes- he is quite right. If you try to fix one coloration with another, you go right down the rabbit hole.

Nonetheless, if you have bright speakers, you must do something. Some choose to not sell, and there are other options beside components with "severe colorations".

Runnin has it right. Get rid of the stranded speaker cable. If that doesn't do it, you will have to kill the tweeter with a resistor. Contact the manufacturer for recommendations.