Infinity Primus 360

Alex2507

Alex2507

Audioholic Slumlord
I understand that the treble dispersion isn't that great. I think some may refer to it as not detailed.

Is there a tweeter available that takes the 360 to the next level in that area?

The cross overs are at 350 Hz and 3.3 kHz. That means that that little 3/4" tweeter is doing everything from 3.3 kHz all the way up to 20 kHz? :eek:
That little fella is gonna need some help. :)

Edit: I have an undetermined amount of time off work and am playing around with them. So far I have one of them gutted to Super Glue the magnetic shields to the baskets. I'm taking baby steps in the modification process. This is step one.
 
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TLS Guy

TLS Guy

Audioholic Jedi
I understand that the treble dispersion isn't that great. I think some may refer to it as not detailed.

Is there a tweeter available that takes the 360 to the next level in that area?

The cross overs are at 350 Hz and 3.3 kHz. That means that that little 3/4" tweeter is doing everything from 3.3 kHz all the way up to 20 kHz? :eek:
That little fella is gonna need some help. :)

Edit: I have an undetermined amount of time off work and am playing around with them. So far I have one of them gutted to Super Glue the magnetic shields to the baskets. I'm taking baby steps in the modification process. This is step one.
Actually the treble dispersion is great. The only defect with the tweeter is that the break up mode is 21KHz and if you had excellent hearing, the associated effects just get into the audio range, if you still have very accurate HF hearing. Most people will not hear this.

The thing I a do notice, the impedance curve shows that in the bass these speakers are not only below four ohms, but current and voltage are out of phase by 45 degrees where impedance is lowest. These things are going to run all but the highest current amps out of gas. If the amp runs out of gas, and almost all receivers will, then the roughness will be noticed in the HF and the tweeter get the blame.

Another thing, as so often in three ways, the polarity of the woofers is reversed in relation to the mid and tweeter, in order to get a satisfactory transition between woofers and mid. Now I'm guessing the speakers are wired to put the woofers to move forward if a battery is connected positive to positive, negative to negative to the speaker. You might want to try this.

Now if you combine this with a center channel speaker, that does not require any reverse polarity at crossover, then the mids and HF are out of phase and there is nothing you can do about it.

Now a crossover at 3.3 KHz is pretty high, there is little power above that point.

You can not swap one driver for another in a design, the crossover has to be designed to a drivers acoustic roll off and they are all different.

The waterfall plot of your speakers is very decent, for speakers in that price range, until the 20 KHz point. I would leave them alone.

Those speakers will give an auto set up fits, in fact I would not use one. There will be severe blending problems with a center speaker because of the reverse polarity of the woofers from mid and HF drivers.
 
Alex2507

Alex2507

Audioholic Slumlord
Matt,

Thanks for the link. Those look like they would just fit. The price looks like 90 of those fancy L's. Any idea's on what that could be in USD?

TLS,

For right now I am leaving them alone. It sounds like you read the review and measurements in Stereophile. My rec'r is a Harman Kardon AVR/430. I don't know if it's high current enough or not. I did read a review that said the 330 (I believe) clips at 25 watts with a 4 ohm load. When I read it I was irritated that they would put a 4 ohm load on a rec'r rated for 8 ohms. It didn't seem fair. :) I'm learning slowly. My rec'r has been doing okay with them so far. I'm a condo dweller so low SPL's are the norm.

Got the glue on and am going to stuff some insulation in the cabinets just to see what happens. The mid range is housed in a plastic can that was full of the stuff that WmAx said to throw out. I'm going to replace that with some of that formaldehyde free white stuff that I have kicking around.

This is a little experimental and can be undone. I'm toying around while the Super Glue dries. Wish me luck. :)
 
Matt34

Matt34

Moderator
Matt,

Thanks for the link. Those look like they would just fit. The price looks like 90 of those fancy L's. Any idea's on what that could be in USD?

TLS,

For right now I am leaving them alone. It sounds like you read the review and measurements in Stereophile. My rec'r is a Harman Kardon AVR/430. I don't know if it's high current enough or not. I did read a review that said the 330 (I believe) clips at 25 watts with a 4 ohm load. When I read it I was irritated that they would put a 4 ohm load on a rec'r rated for 8 ohms. It didn't seem fair. :) I'm learning slowly. My rec'r has been doing okay with them so far. I'm a condo dweller so low SPL's are the norm.

Got the glue on and am going to stuff some insulation in the cabinets just to see what happens. The mid range is housed in a plastic can that was full of the stuff that WmAx said to throw out. I'm going to replace that with some of that formaldehyde free white stuff that I have kicking around.

This is a little experimental and can be undone. I'm toying around while the Super Glue dries. Wish me luck. :)
I think I got a little ahead of myself by recommending those tweeters. They may not be ideal for use with the stock crossover so I would investigate that possiblity first. Those are tweeters that were recommended to me by WmAx but in an active crossover configuration.
 
Adam

Adam

Audioholic Jedi
The price looks like 90 of those fancy L's. Any idea's on what that could be in USD?
Looks like you won't be going with those, now, but...one British pound (the "fancy L's" :)) is about two US dollars right now.
 
WmAx

WmAx

Audioholic Samurai
Actually the treble dispersion is great. The only defect with the tweeter is that the break up mode is 21KHz and if you had excellent hearing, the associated effects just get into the audio range, if you still have very accurate HF hearing. Most people will not hear this.
Actually, the resonance on the tweeter here is extremely well damped(enough that it never peaks over the reference signal; it resides under the main signal by several dB); and it's of an extreme high Q(at leastQ=50); it's completely inaudible under any circumstance of music program, according to the perceptual research on resonances. Now, assuming a signal of white/pink noise, and someone with superb hearing extension, audibility is a slight possibility.

The tweeter dispersion is not very good ultimately; though it's perhaps good by the 'normal' standard; it's about average/on par with every other 3/4" dome tweeter. I have one of these tweeters on hand; it's response at 10kHz at 60 degrees is down by 9db, and by 15khz at 60 degrees, it's down by 15 dB. The Fountek tweeter mentioned earlier, at 15kHz at 60 degrees, is only down by about 6dB.

-Chris
 
WmAx

WmAx

Audioholic Samurai
I think I got a little ahead of myself by recommending those tweeters. They may not be ideal for use with the stock crossover so I would investigate that possiblity first. Those are tweeters that were recommended to me by WmAx but in an active crossover configuration.
The Fountek tweeter does not fit as-is. You have to cut down the face plate and cut some notches in the cabinet to fit the larger rear section of the Fountek tweeter in place of the stock one.

A new high pass section for the stock crossover is required to use the Fountek.

-Chris
 
Alex2507

Alex2507

Audioholic Slumlord
The Fountek tweeter does not fit as-is. You have to cut down the face plate and cut some notches in the cabinet to fit the larger rear section of the Fountek tweeter in place of the stock one.

A new high pass section for the stock crossover is required to use the Fountek.

-Chris
All that aside, according to Adam that's about $180 worth of Tweeters. :eek:

The EQ I have has a RTA in it with a small mic. To get anything close to a flat response, it wants to boost the 16 kHz band by 8dB. Avaserfi had mentioned something to me about replacing the stock tweeter. I hoped that the fix would be cheap and easy. Like ... well, never mind. :D

Is there a a teeter out there that can be swapped with this one to get an improvement? The thing about it that bugs me is that when I watch a DVD of The Blue Man Group, there is a part where one of the Blue Men hits his drum sticks together three times and I can't hear it. That makes me wonder about what else I'm missing.

I have the speakers toed in enough to where the tweeters would intersect about a foot from my face. I don't really concern myself much with what happens in the rest of the room. I'm the only one who cares. The good off axis response of the 360's is all anybody else gets, at least for now. :)

Edit: BTW, Out of the six magnetic shields, at least four of them had that rattle after getting a good knuckle wrap. My knuckles hurt. :rolleyes: After the glue dried, I checked them again and added more glue to any suspect areas.
 
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WmAx

WmAx

Audioholic Samurai
All that aside, according to Adam that's about $180 worth of Tweeters. :eek:

The EQ I have has a RTA in it with a small mic. To get anything close to a flat response, it wants to boost the 16 kHz band by 8dB. Avaserfi had mentioned something to me about replacing the stock tweeter. I hoped that the fix would be cheap and easy. Like ... well, never mind. :D

Is there a a teeter out there that can be swapped with this one to get an improvement? The thing about it that bugs me is that when I watch a DVD of The Blue Man Group, there is a part where one of the Blue Men hits his drum sticks together three times and I can't hear it. That makes me wonder about what else I'm missing.

I have the speakers toed in enough to where the tweeters would intersect about a foot from my face. I don't really concern myself much with what happens in the rest of the room. I'm the only one who cares. The good off axis response of the 360's is all anybody else gets, at least for now. :)
The response, anechoic, is not down by anywhere near that amount, assuming your speakers are non-defective. 8dB down in room, though, is probably close to right, for the most natural tonal balance on commercial recordings, if you are trying to replicate the tonal balance of live unamplified acoustic presentations in the mid or far field perspective. Of course, not everyone is looking for this perspective. Also, not all recordings need this compensation: just most.

Your easiest(most accurate/precise) solution is to get a proper equalizer and apply a shelving filter to boost the high end gradually to counter-act the room response drop at the listening position.

-Chris
 
Alex2507

Alex2507

Audioholic Slumlord
With time I will get a proper EQ. It's just the way it works for me. I have to lust after a thing for a while, then it comes. I use to have the Primus 250's and I really wanted the 360's for a long time. When the time came, the 360's came with the rest of the surround system. My Behringer DCX and EP days are still ahead of me. This is what I have to play with now. :)

Edit: I installed some duct liner and other insulation while I had the drivers out. Probably the wrong kind and not enough but the echo has diminished. They are not B&W's but I'm not done yet either. The real mission was to get the cans tended to.
 
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WmAx

WmAx

Audioholic Samurai
With time I will get a proper EQ. It's just the way it works for me. I have to lust after a thing for a while, then it comes. I use to have the Primus 250's and I really wanted the 360's for a long time. When the time came, the 360's came with the rest of the surround system. My Behringer DCX and EP days are still ahead of me. This is what I have to play with now. :)

Edit: I installed some duct liner and other insulation while I had the drivers out. Probably the wrong kind and not enough but the echo has diminished. They are not B&W's but I'm not done yet either. The real mission was to get the cans tended to.
Yes, it is amazing, that they did not bother to use sufficient acoustic stuffing material(s) to prevent basic internal reverberation within the relevant operating bandwidth of the drivers.

-Chris
 
Alex2507

Alex2507

Audioholic Slumlord
I have officially become less of a man. I bought fabric! :eek: The worst part is that the 3M 77 Spray adhesive that I used to glue some of the insulation in place got on my knuckles. Well when it came off little by little the hair on my knuckles came off with it. Now I'm buying fabric with hairless knuckles. I feel like such a fem.

Like Chris said, $1/yard at Walmart. $6 later and I'm set for life. I got lucky I guess cause they had black and you can blow right through it like it wasn't there almost.

I have a question and a suggestion about the glue. Walmart had the glue in 6-packs for $0.98. Home Depot had 12-packs of a little larger sizes for $5. My suggestion is get 24-30 of these things. Apply it 3 times, letting it dry each time. There are 2 places to run streams of glue, against the basket and at the outer edge of the can. Rest the speaker on the can, cone side up while it dries.

My question is, does that about cover it? Oh yeah, how long does it take for that glue to dry?

Edit: Now that the glue is drying, I am wondering about what TLS talked about in post #3 regarding the amp section of my receiver and how these speakers would be affected/afflicted by the H/K AVR 430. PENG?:) It's not that I'm clueless so much as I don't have much of a clue. I could use a dumbed down lesson here. How about an explanation of the 'high current' term and some examples.

The measurements and graphs for the 360 are here:
http://www.stereophile.com/budgetcomponents/605infinity/index3.html
 
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P

PENG

Audioholic Slumlord
Edit: Now that the glue is drying, I am wondering about what TLS talked about in post #3 regarding the amp section of my receiver and how these speakers would be affected/afflicted by the H/K AVR 430. PENG?:) It's not that I'm clueless so much as I don't have much of a clue. I could use a dumbed down lesson here. How about an explanation of the 'high current' term and some examples.
I agree with TLS (at least in this case:D). Yamaha, Denon, Sony ES all claim high current capable. How high is high?

I guess in general HK receivers have relatively larger power supplies in them so they do better (relatively speaking) in ACD but they may actually do worse than their Yamaha, Pioneer Elite, Denon, Marantz counterparts in 1 and 2 channel driven situations including when driving less than 8 ohm loads.

In the review you mentioned earlier (I assume we read the same S&V one), the 330 did not clip at 25W into 4 ohms, instead, the protective system kicked in and shut the unit down before (after about 0.5 seconds if I remember correctly) it had a chance to clip. If HK chose not to play it safe, it would most likely have delivered much high output before it clipped. While this may raise little concern in real world situations, it did demonstrate that HK's claim of high current is for a very short duration (instantaneous) only.

I know I am stating the obvious, but the 430 may or may not let you get the best out of the Primus depending on many other things. So for peace of mind you may want to add a 2 channel amp (300WX2) and find out for yourself if you can hear a difference from the L/R speakers.
 
Alex2507

Alex2507

Audioholic Slumlord
you may want to add a 2 channel amp (300WX2) and find out for yourself if you can hear a difference from the L/R speakers.
I may add a Peavey P.V.-8.5C just so I can EQ out of the pre-outs. Right now I am EQing L&R audio out from my DVD player and running it into my rec'r. The Peavey amp is a pain due to 1/4" jacks and some kind of Quasi-Shield mumbo-jumbo and bare wire connection options that I have yet to get my mind around. I'm surprised that I can hear a difference after this simple mod on the 360's. I doubt that I'll hear anything with an added amp as I don't turn it loud very often. We'll see.

Eventually I'll use the RTA and see what has happened to my FR line since the mod.

For the time being I'll say that cutting the magnetic shields off has got to be easier and quicker than all that gluing. The shields are rock solid though.

Anybody have any thoughts on modifying my center channel? It's an Infinity Primus PC350. TLS, I would think that the drivers in this are out of phase just like in the 360's. In the 360 the midrange is in it's own little can within the speaker so it's separated from the woofers. Any thoughts?
 
WmAx

WmAx

Audioholic Samurai
I may add a Peavey P.V.-8.5C just so I can EQ out of the pre-outs. Right now I am EQing L&R audio out from my DVD player and running it into my rec'r. The Peavey amp is a pain due to 1/4" jacks and some kind of Quasi-Shield mumbo-jumbo and bare wire connection options that I have yet to get my mind around. I'm surprised that I can hear a difference after this simple mod on the 360's. I doubt that I'll hear anything with an added amp as I don't turn it loud very often. We'll see.

Eventually I'll use the RTA and see what has happened to my FR line since the mod.

For the time being I'll say that cutting the magnetic shields off has got to be easier and quicker than all that gluing. The shields are rock solid though.

Anybody have any thoughts on modifying my center channel? It's an Infinity Primus PC350. TLS, I would think that the drivers in this are out of phase just like in the 360's. In the 360 the midrange is in it's own little can within the speaker so it's separated from the woofers. Any thoughts?
You may not have to remove the magnetic shield cans to stop the vibration. I have so far tested an alternative method to stop such vibration on two other speakers(though not primuses). I used liquid super glue in a tube. I squirted a generous amount at the seam of the magnetic shield can where it connects to the driver motor, allowing it run down in the crack. After the glue dried - the play/vibration has been removed from the two speakers I have tried this on so far.

-Chris
 
J

Joe Schmoe

Audioholic Ninja
I understand that the treble dispersion isn't that great. I think some may refer to it as not detailed.
Where did this alleged "understanding" come from?:confused: It is simply false. The Primuses have extremely detailed highs and wide dispersion (leading to excellent imaging.)
 
Alex2507

Alex2507

Audioholic Slumlord
Where did this alleged "understanding" come from?:confused: It is simply false.
To be honest with you I can't remember where my false alleged understanding came from. I've been doing a lot of reading about them recently and have exchanged a few PM's about them. Another possible source is some threads that I have subscribed to regarding their modification recommendations. It could have come from anywhere. It's not like I have an ax to grind in regards to these speakers.
I own a pair and I like them.

Even though I can't tell you where exactly my false alleged understanding came from, I can say that it is supported in post #7. There are even measurements cited there with little numbers and like,
technical stuff.

In case you can understand the graphs better than I can, post #14 has a link to a whole mess of them that might support my false alleged understanding, or not. I'm just not at a level where I can interpret data presented like that. I'm working on it though.

Thank you for your opinion. :rolleyes: BTW, where did it come from?
I'm simply dieing to know.
 
J

Joe Schmoe

Audioholic Ninja
Thank you for your opinion. :rolleyes: BTW, where did it come from?
I'm simply dieing to know.
It came from the only place that matters: direct experience. I own a pair of 250s, so I know with 100% certainty that they have exceptionally detailed highs, excellent soundstage/imaging, and a very wide sweet spot.
 
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