nobbie Insignia project!

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Hey all! so the other day I came across some of the famous (or infamous) Insignia speakers from best buy at a real bargain (i know some BB employees ;) )

Anyway, I am a college student and have limited funds, so I am looking for a small project. I have decided to modify these speakers and am considering a few options suggested on the forums.

Zaphs notch filter here
GR Research's upgrade here
Dave's Speaker page here
MurphyBlaster here

So you know I have never made a XO or anything like that, but I am decently familiar with soldering, so I could possibly give it a try. I am looking for the best overall performance that I can achieve for a low amount of money.

Here is a question, which mod would any of you really recommend? is GR's worth the money? Has anyone else done Dave's mod and had any success? Should I just deaden and damp the box and attempt the MurphyBlaster XO? any thoughts would be great!

Like I said, I would like to know if you have personal experience with these mods, and I would like to avoid the whole "well I heard from XXX that is was good/bad"... first hand would be best.

Thanks in advance ;)
 
First off I haven't modded these. Looking at the modification websites you linked to I would pick either Dennis or Zaph's. GR's is too expensive for this level of speaker, and Dave's is irreversible for future tweaking. If it were my pair of speakers and I was going to be taking them apart I would go with Dennis' crossover. Zaph's add-on notch filters would be good if I didn't want to take apart the speaker, but if I'm going to go through the trouble to take it apart, I might as well use a redesigned crossover like Dennis'. The water putty cabinet wall modification a la GR's site and mass loaded acoustic absorption foam recommended by Zaph would also be nice upgrades.

Good luck,
David
 
Thanks for the reply gtforme00!

Even though you have not modded these speakers yourself, the reply still seems well informed. I am thinking I will skip GR's, but keep Dave's on the back burner unless someone else convinces me otherwise.

I am going to use the Water putty and hopefully some sort of acoustic absorption foam in there regardless of what I choose. Additionally, I am going to reinforce the top and bottom with another sheet of MDF that I have sitting around. plus I think that I might try and re-do the veneering for fun :)

OK, so you suggest Dennis' XO, anyone else?
 
Originally posted by BERENO
OK, so you suggest Dennis' XO, anyone else?

Dennis Murphy's is probably the best if you don't care to maximally improve the response. It's by far the most cost effective of them all IMO. I can't comment on sound quality changes to the box, but it certainly can't hurt to stiffen the boxes. I have serious doubts about the expensive crossover recommendations. The driver is just not good enough for that to be worth the cost IMO. The tweeter is the real limiting factor and that cannot be improved as the woofer can be.

I also differ with the idea that tweaking the driver as I did will limit future tweaks. It is irreversible, yes, but I have little doubt that it is an improvement without need of reversing. It's also surprisingly consistent. Every driver I've modified has shown improvement in unit-to-unit consistency. It makes further tweaking easier as I see it. It also works well with both Dennis' and my crossover.

That said, my Minimalist design is surprisingly close to Dennis' in system response. I've got both in SoundEasy using the digital filter. They sound very close. Dennis tried to re-use the OEM crossover components, I did not. I did try to keep component sizes reasonable.

Some weeks ago I wanted to construct a crossover to be done with it. I ended up spending more time on the crossover (it's so easy with SoundEasy, pardon the pun). I've got what I think is better yet and have plans to update my web site. There is still a small bit of interest out there. I've tried to minimize the crossover as much as possible without compromise in the sound. I think I've got that and it allows for some personal tweaking in the high end. It even re-uses one inductor, though a second one needs to go in series with it to get the value needed. The best part is that if the driver is modified, the large value trap can be eliminated, though it's possible to improve the woofer further. The cost doesn't make that attractive, however, as it requires a 5.6mH inductor.

In the end, mod the driver and one of the inductors is somewhat large, around 1.75-2.0mH depending on the version (trap/no trap). All other inductors and caps are very small. I don't know when I'll get the time to update my web site, but I'll see if I can upload the schematics and driver responses this weekend in a temporary folder if there's interest.

I will add one comment. I don't see how Dennis got the target response he did in the 1K area given the extreme dips I measured in all of my units prior to modifying them. I can't get that flat a response even with a very large trap. The raw responses I measured are just too extreme for a passive filter to smooth that well.

Dave
 
Dave,

So far, the cheapest I can seem to get Dennis' XO is $41.60 before shipping from madisound. Are your XOs generally better performers than Dennis'? and can they be had for around the same price?

I was amazed at how flat Dennis was able to get the response with his reworked XO... from 600 to about 4500 is within 2db! If it was really that flat woulnt they be new "giant killers"? That is the reason I was going to go with his XO. However I am basing my decision solely on what he posted, hence the reason I am here asking people if they have had such results themselves.

You bring up an interesting point; are you suggesting that the wet look dampening material will help reduce resonances in the woofer, which will allow one to create a more simple (and thus cheaper) XO?

I've got what I think is better yet and have plans to update my web site

does this new updated XO take into account the dampening compound you applied to your woofers?

All in all I am looking for the best performance I can squeeze out of these drivers in their given cabinets for the least amount of money. I would like to spend no more than $100.00 total on these speakers. I already have $45.57 into the speakers, and $9.21 into the water putty so that leaves me $45.22 in XO parts and possibly the dampening compound if I go that route.

I dont think I can price out your XO because I dont know enough about it yet, what do you think the price would come out to be??
 
BERENO said:
Dave,

So far, the cheapest I can seem to get Dennis' XO is $41.60 before shipping from madisound. Are your XOs generally better performers than Dennis'?


I'd have to say no. Dennis puts out really good and well regarded designs.

and can they be had for around the same price?

I have yet to tally the cost of mine. I do suspect that the one I'm using now will be cheaper overall. It can work without the woofer mod, but the best response includes the mod.

I was amazed at how flat Dennis was able to get the response with his reworked XO... from 600 to about 4500 is within 2db! If it was really that flat woulnt they be new "giant killers"? That is the reason I was going to go with his XO. However I am basing my decision solely on what he posted, hence the reason I am here asking people if they have had such results themselves.

It is commendably flat. As I said, I'm still puzzled about the 1K area. The rest isn't too difficult for matching a target. When I model it with my measurements of a treated driver, it doesn't show as being flat. It isn't with mine, either, for that matter. The Qs of the peak/dip require unreasonable values. Part of it may be the measurement technique. I've been using a rectangular window rather than Blackman-Harris. The latter tends to smooth the response and I sometimes use it for tweeters.

They will never be giant killers IMO. The reason is the tweeter. It can't be improved much if at all. The issue is the far from optimal horn loading that the woofer provides. That can't be changed. It's excellent cost/performance ratio, yes, but no giant killer.

You bring up an interesting point; are you suggesting that the wet look dampening material will help reduce resonances in the woofer, which will allow one to create a more simple (and thus cheaper) XO?

Yes.

does this new updated XO take into account the dampening compound you applied to your woofers?

Yes.

All in all I am looking for the best performance I can squeeze out of these drivers in their given cabinets for the least amount of money. I would like to spend no more than $100.00 total on these speakers. I already have $45.57 into the speakers, and $9.21 into the water putty so that leaves me $45.22 in XO parts and possibly the dampening compound if I go that route.

The Wet Look alone with shipping is about $18 I think. That would leave you about $26 or so. Even with re-using some of the OEM parts, I doubt that this will cover the rest, though the component values aren't high. However, though Dennis' XO re-uses inductors, there are two very large caps that I think might break your budget as well if you get decent quality (i.e. non-electrolytic).

I dont think I can price out your XO because I dont know enough about it yet, what do you think the price would come out to be??

As I said I haven't tallied it. I'll try to get to posting it and a rough tally this weekend. I've let this sit long enough. Plus I just finished the hard part of building a covered basement entrance, so I can get back to speakers a bit more.

Dave
 
Thanks for all the info Dave! It really is nice to see that there are people willing to help those who are a bit newer to the "hobby" :)

It can work without the woofer mod, but the best response includes the mod
I am assuming you are referring to the Wet Look...

I will wait and see how your new XO turns out before I choose between the two. If they perform nearly the same without the woofer mod (and are about the same total cost), I will choose yours, knowing that the Wet Look will help the most on your XO. This will allow me to use the Wet Look sometime in the future when I have more money :D
 
Bereno,
I was supposed to help a friend build his HT system round the Insignias and it never happened. He actually drove from Canada to the US to purchase the speakers but then decided they were too big for him... He has the biggest, most empty basement to be used as an HT room... How can the speakers be too big, I DON'T KNOW!

Glad I finally helped someone take an enlightened decision.

Peter
 
He actually drove from Canada to the US to purchase the speakers but then decided they were too big for him... He has the biggest, most empty basement to be used as an HT room...

Haha I'm envious of his basement :D So he was going to build a HT around the insignias?? he must not have very high standards for audio... :confused: I only bought them because Im a starving college student with no money!
Thanks again
 
BERENO said:

... he must not have very high standards for audio... :confused: I only bought them because I'm a starving college student with no money...

Don' under estimate them. For the money you will get some bang for your buck. The home-made x-over will allow you to say: "I made that". The overall quality and potential loudness these speakers will allow will make you one of the better equipped students in your school.

I really think you will be happy.

Peter
 
Yup those are them. He had the coil on them "re-wound" as my dad says it to match the A-7 I believe... He got them for next to nothing from a guy who did not know what he had. They they used to be in an older movie theater, and when someone bought it, they decided to renovate the sound system, among other things. My dad who used to be in construction was overseeing part of the project was able to get his hands on these at a steal. So he built the box to speck, and had the coils redone. Good to go at a fraction of their cost! Great speakers :D
 
BERENO said:
Dave,

Did you get around to updating your XO this weekend? I did not see an update on the site...

I haven't updated the web pages. I won't do that until I'm sure of what I want to add to it and until I've actually constructed/measured the crossover I'll put it. In the mean time, I did upload some screen captures of the crossovers as I've listened to them using the digital filter in SoundEasy. It let's me listen to any crossover no matter the complexity or cost. Now, though, I have to decide on the compromises I'll make in actually building one.

I've got two of mine listed, Dennis Murphy's and a comparison. Note that on the latter there's a drop in the top octave of a full db in mine. My original one was almost a perfect overlay with Dennis', but I found it a bit fatiguing over time so I lowered the tweeter level, just my preference.

I'll be constructing the first one, but I have another one that is a bit better. I rushed to capture/upload these last night, so I think that I'll have a small change from the first one below. That one shows the peak that occurs by simply removing the (uneconomical) trap.

Simplified without the 1K trap

Simplified with the 1K trap

Dennis Murphy XO with modded woofer

final_simplified_vs_murphy.gif


All of these are with my woofer tweak, including Dennis' crossover. Without the mod, the dip would be several db deeper with much higher Q. My page on tweaking the woofer shows the difference in the raw response before/after.

insignia_iec_unit4_woofer_new_vs_final.gif


The values are shown for each crossover. I can't say when I'll update my page to include a BOM, but you can work one up yourself if you're looking to do it sooner. Most values are standard, at least using the Solen catalog.

One last note. Mine is a non-symmetric XO, something of 5th order LP and 6th order HP. Due to the driver being coaxial (not coincident, there is a tiny relative acoustic offset), the response has no lobing issues no matter the type or axis. This allows almost any combination that yields a reasonably flat response. The connection is direct, not inverted, even with the unusual slope combination. There will be woofer off-axis rolloff, but a decently low Fc takes that into account. I'll put details in my web page update, but again, that may be a while.

Dave
 
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