What differences would I hear?

[Alex2507]

I'm curious about what improvements would be heard by using a seperate amp or integrated amp to drive my Infinity Primus 250 speakers as opposed to using the Zone 2 feature on my H/K AVR 430.

Usually my volume is kept pretty low because of neighbors so I'm primarily concerned with clarity. I will at some point upgrade the speakers but am keeping these for now. Thanks.

 

[WmAx]

I'm curious about what improvements would be heard by using a seperate amp or integrated amp to drive my Infinity Primus 250 speakers as opposed to using the Zone 2 feature on my H/K AVR 430.

Usually my volume is kept pretty low because of neighbors so I'm primarily concerned with clarity. I will at some point upgrade the speakers but am keeping these for now. Thanks.

You can expect no improvement in your specific situation from changing the amplification unless the current amplifier has a defective output.

For real improvement, you can do some modifications to that speaker that will take about 2-3 hours. You can remove the drivers, remove the acoustic batting and throw away the acoustic batting(it's worthless). Install Peel N' Seal(a Dynamat alternative that is lower in cost) in layers on all inside walls until you get about 1/3" thick. Now attach 2" thick high density mineral board on all interior walls(use 4" on bottom floor of cabinet and directly behind drivers on back wall) as an effective acoustic batting. Re-install drivers.

Optional step: Use a dremel tool(and full face shield) with a metal cutting disc and remove the magnetic shield cans on the back of the Primus mid-woofers. Every primus mid or mid-woofer I have seen so far as a rattle where the shield can is not securely attached to the edges of the motor, thus able to rattle against the magnet. The resulting rattle is high pitched, and at first, sounds like a upper midrange distortion; but it's that poorly mounted shield.

You will have a substantially improved midrange. If you need a percieved tighter bass, just add in more of the mineral board; the more you add the more it subdues the bass peak present on Primus model speakers.

-Chris

 

[Alex2507]

Thanks. That really is an eye opener. Of course "real improvement" is what I'm after. I'm pleasantly surprised by your use of the term "bass peak" because it addresses something I was noticing but didn't have the vocabulary to describe. I thought that I was getting that due to the speakers being placed too close to the corners of the room, the result of an unfortunate space constraint, which is something I am still going to play around with.

I'm not sure where to get the Peel N' Seal and mineral fiber board. Would you be able to suggest a source?

 

[WmAx]

Thanks. That really is an eye opener. Of course "real improvement" is what I'm after. I'm pleasantly surprised by your use of the term "bass peak" because it addresses something I was noticing but didn't have the vocabulary to describe. I thought that I was getting that due to the speakers being placed too close to the corners of the room, the result of an unfortunate space constraint, which is something I am still going to play around with.

I'm not sure where to get the Peel N' Seal and mineral fiber board. Would you be able to suggest a source?

You can get Peel N' Seal from Lowe's. It is in the roofing department and sold as a flashing repair in rolled form. It costs about $15 dollar per roll, and you will need at least 2 rolls per speaker. The mineral board is purchased usually at commercial/industrial insulation contractors and supply houses. You buy it usually in shrink-wrapped lots of 6 units of 2" x 24" x 48". Locally, it costs me about $37 per lot. This is far more than you need. 1 piece of the material would probably do both speakers. If you can't find a source locally, or if you don't want to have to buy that much, I can sell you a piece of it for cost plus actual shipping. Note: when you install Peel N' Seal use a hairdryer or heat gun to heat up the first layer you put in so it has maximum adhesion to the MDF cabinet walls. You don' t have to heat the additional layers, as it sticks to the backing of itself very good, but be sure that they are at least room temperature. To install the mineral board, it should be easy to use a hot melt glue gun; use generous amounts of glue. Alternatively, you can use 2" or 2 1/4" deck screws(not drywall - the threads are usually too fine) along with large diameter washers. Drive them in about 1/2", but obviously be careful or you will drive them all the way through the walls. Before installing the mineral wool board you want to use some low cost acoustically transparent material (available at the $1/yard bargain shelf at Wal-Mart) and wrap it around the mineral board to prevent fibers from becoming loose and possibly emitting from the port into your air.

-Chris

 

[Alex2507]

WmAx,

I found a thread where you described an extensive mod to the Primus line involving an active cross over and dual subs. I just wanted to let you know that as soon as I finish a couple of on going projects, I'm all in. It's odd that I started asking questions regarding these speakers in "Loudspeakers" and brought it here looking to keep it forum appropriate when I started thinking about amps only to have it seem like I should be back in "Loudspeakers".

While I'm here I wanted to ask if you had any mod suggestions for these:
http://cgi.ebay.com/Cinema-Vision-2-Way-Dual-5-Inch-Home-Theater-Speakers_W0QQitemZ150192122826QQihZ005QQcategoryZ32861QQcmdZViewItem

They are being used for Front, Left and Center in a 5.1 set up as my sig indicates.My carpentry skills are profound. My access to tools is extensive. It's my tech info that is lacking. Thanks.

 

[avaserfi]

I found a thread where you described an extensive mod to the Primus line involving an active cross over and dual subs. I just wanted to let you know that as soon as I finish a couple of on going projects, I'm all in. It's odd that I started asking questions regarding these speakers in "Loudspeakers" and brought it here looking to keep it forum appropriate when I started thinking about amps only to have it seem like I should be back in "Loudspeakers".

If you implement proper bracing in your Primus 250s along side proper internal dampening the F3 of the speakers will likely end up around 70-90Hz. To further increase fidelity it would be advisable to purchase stereo subwoofers and a quality digital crossover/equalizer (Behringer DCX2496 is a great choice) to seamlessly integrate the subwoofers and achieve the exact desired response. Also, for optimal sound quality do not forget room treatments as the best speakers in the world will not sound it unless the room is treated properly.

While I'm here I wanted to ask if you had any mod suggestions for these:
http://cgi.ebay.com/Cinema-Vision-2-Way-Dual-5-Inch-Home-Theater-Speakers_W0QQitemZ150192122826QQihZ005QQcategoryZ32861QQcmdZViewItem

They are being used for Front, Left and Center in a 5.1 set up as my sig indicates.My carpentry skills are profound. My access to tools is extensive. It's my tech info that is lacking. Thanks.

While nearly all speakers can be modified the question remains if it is worth spending the time to modify them. Substantial amounts of time need be spent measuring the speakers performance on a whole from the drivers to the cabinet and the crossover. Once this is done it can be determined if it is worth the time and effort to modify the speaker.

 

[WmAx]

If you implement proper bracing in your Primus 250s along side proper internal dampening the F3 of the speakers will likely end up around 70-90Hz. To further increase fidelity it would be advisable to purchase stereo subwoofers and a quality digital crossover/equalizer (Behringer DCX2496 is a great choice) to seamlessly integrate the subwoofers and achieve the exact desired response. Also, for optimal sound quality do not forget room treatments as the best speakers in the world will not sound it unless the room is treated properly.

The specific modification that I recommended to Alex will not affect LF response much, unless he adds extra damping material to cure the built-in bass hump on the Primus speakers.

-Chris

 

[WmAx]

WmAx,

I found a thread where you described an extensive mod to the Primus line involving an active cross over and dual subs. I just wanted to let you know that as soon as I finish a couple of on going projects, I'm all in. It's odd that I started asking questions regarding these speakers in "Loudspeakers" and brought it here looking to keep it forum appropriate when I started thinking about amps only to have it seem like I should be back in "Loudspeakers".

Well, the modified speakers that you speak of are probably my computer monitor speakers. The level of modification done is at the extreme end. In addition, if you incorporate that level of modification, what avaserfi said about LF extension will be true; you will not have a F3 below 70-90z due to the reduced cabinet volume and having to use the volume in a sealed configuration as opposed to vented. In addition, if you intended to go fully active, in order to program the DCX for mid/treble integration requires acoustical measurement hardware, software and the knowledge of how to use it properly.

While I'm here I wanted to ask if you had any mod suggestions for these:
http://cgi.ebay.com/Cinema-Vision-2-Way-Dual-5-Inch-Home-Theater-Speakers_W0QQitemZ150192122826QQihZ005QQcategoryZ32861QQcmdZViewItem

I have no suggestions on this speaker system. If you can provide in depth 3rd party measurements I will able to comment. Until then, I can not recommend that you modify this JBL speaker.

If you are interested, I can recommend certain speakers that have excellent drivers and crossovers, but have severely lacking cabinets(as do most speakers) that would benefit greatly from cabinet modifications.

-Chris

 

[avaserfi]

I found a thread where you described an extensive mod to the Primus line involving an active cross over and dual subs. I just wanted to let you know that as soon as I finish a couple of on going projects, I'm all in.

The specific modification that I recommended to Alex will not affect LF response much, unless he adds extra damping material to cure the built-in bass hump on the Primus speakers.

-Chris

I was referring to the other thread and trying to reiterate the importance of the DCX and the stereo subs was paramount to audio quality in the given situation.

 

[Alex2507]

Avaserfi,

That is indeed the thread that I was refering to. I'm a little short on time at the moment. I believe you are trying to get me to understand something before I go off 1/2 cocked on this. I'm lacking the technical knowledge to have an intelligent discussion and am looking forward to changing that.

WmAx,

When time permits I'll get back to this. Right now let me just thank you for getting me pointed in the right direction. This kind of thing is right up my alley, ability-wise.

Thanks for pointing out the short commings of those paticular JBL's with what I perceived to be more diplomacy than I thought was possible.You guys are great. Thanks.

 

[SHAKES88LB]

hello everyone!

im new to this site, and as i can see by some of these posts, am new to stereo equipment knowledge!!! which brings me to my question, about loudspeakers. why are many two-way, and many three-way? isnt 3-way a better wider range speaker?