Best "Off the Shelf" speakers for DIY mods.

percy

Member
2004-04-25 5:47 pm
CA
What are the currently the best candidates of buying a speaker off the shelf and modifying the crossover and cabinet to improve the sound. Still using the same drivers though.

I know the Insignia 2-way coax is quite popular, but any others besides that ?

I saw one KLH at Radioshack the other day for $30. A 6.5" and 3/8" tweeter. I think it was this one -
http://www.radioshack.com/product/index.jsp?productId=2879619
Wonder how good of a candidate that one is ?
 
At this price level, I rather doubt that the drivers quality and performance are worth the effort of BUYING and modding the speaker. Since you want to change the cabinet and crossover, you should be better off buying just new, better drivers.

It also depends on what you're looking for: good speakers or just DIY fun.

I've modded my speakers(B&W 602S3) heavily because, in time, I have become convinced that the drivers do have more potential (actually the woofer, which is pretty much the only thing left from B&W, besides the front baffle :devilr: ).
 

percy

Member
2004-04-25 5:47 pm
CA
bzfcocon said:
Since you want to change the cabinet and crossover


sorry if I wasn't clear. I meant keeping the cabinet and the drivers. Obviously if you change drivers and cabinets then it doesn't make any sense.

thats the whole idea about the original question - I guess if asked another way - Which off the shelf speakers have decent drivers that will benefit from a crossover redesign ?
Cabinet treatment is not a big deal for a small bookshelf, ofcourse as long as the box is already of reasonable size for the driver used.
 
Don't waste your money. I had almost that exact same set of speakers I bought from BestBuy for around ~$30 some 4 years ago. They sounded like complete garbage.

Over the years I had them I tried many different crossovers and even a few different tweeters. Nothing helped. They eventually ended up in the garbage where they belonged.:smash:
 

x. onasis

Member
2003-01-03 2:48 am
NYS
They probably sounded similar to the KLH's.

I donated my Insignias to a charity event that raffled them off. They raised about $130 for the cause, and someone got them for $2. They sounded OK to have "tunes" in a room, and maybe "great" for $30, but they didn't compare to any I've built from plans shared here.

The problem with your quest is that "off the shelf" speakers usually have crappy boxes, crappy drivers, combined with crappy crossovers, and replacing the XO, will be a rather expensive swap with minimal gain. The Insignia's had a little going for them in each area, and their cabs looked real nice for the price.

I haven't seen a recent example where a commercially produced product used decent drivers, an attractive, well constructed enclosure, then skimped on the XO.

Older speakers found used, may have drivers worth playing with, but when you balance the time and effort to build proper cabs for them, design and purchase parts for a proper XO, the cost for good drivers isn't that great.
 

peter_m

Member
2007-05-14 7:33 am
Bestbuy recently had the famous Insignia Bookshelf speakers on sale at 49$. A friend of mine got me a pair from the US and he was very impressed with them. I was not as impressed as the highs are ear shattering and gave me a head ache. Could also have been the cone break up as I can hear a little sibilance. One thing I noticed is that you can drive them pretty loud. I plan to modify the x-over in my pair as I find them unbearable. Here is the new x-over: http://murphyblaster.com/content.php?f=insignia.html

Peter
 

Iain McNeill

diyAudio Moderator Emeritus
I got a pair of AR3b's for $25. Foam surrounds were rotted out.

I sawzall'ed out the baffle and reloaded with Vifa/Morel & DSP XO tri-amp - sweet!

I couldn't build a cabinet like that for $12.50! That's a deal!!!!!
 

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Don't bother with really cheap speakers you will spend more trying to fix them than they are worth.

Best bet is to find an old set of speakers from the 70/80s which will have decent cabinets and quite probably had OK drive units. Then update them.

I got hold of an old set of Celestion Ditton 15 Cabinets that some chap was giving away on freecycle, he had tried to sell the drive units on ebay and sold some bits and just didn't want the cabinets laying arround. I polished them up with some restoration polish and they now look great.

I am planning to put a set of Celestion TF0818 bass/mids in and either a Monacor DT 26 or possibly I might try a old pair of prototype tweeters I have lying arround first to see if I can get them to intergrate. The Monacor has the advantage that it will play a bit lower than most. Hoping to build a high efficiency set of speakers that sound fast and clean with acceptable but not excessive bass response.

The Celestions still have the passive radiators in but I am not sure if I am going to use them as I usually find they give a rather slow bass sound due to stored energy. So I may replace them with a port instead.

Anyway the point of all this ramble was - you are much better off paying for an older pair of speakers from a second hand shop or off ebay rather than buying a pair of really poor cheap speakers.

Regards,
Andrew
 
gfiandy said:
The Celestions still have the passive radiators in but I am not sure if I am going to use them as I usually find they give a rather slow bass sound due to stored energy. So I may replace them with a port instead.

PRs and ports are both examples of bass reflex systems. Ports have as much "stored energy" as a PR. In fact, a port is simply a special case of the bass reflex system.

Back on topic, the Insignia, though not a great speaker, is certainly one of those good "bang-for-the-buck" systems. If one does not have a lot to spend, it's a good option. It can be improved with modifications that don't cost a lot. Dennis Murphy's mods will be such an improvement.

It won't have any real bass, but then any 2-way system no matter the drivers used is going to be a compromise, especially in the bass.

Dave
 

Salas

diyAudio Chief Moderator
Paid Member
2002-10-08 11:31 am
Athens-Greece
dlr said:


PRs and ports are both examples of bass reflex systems. Ports have as much "stored energy" as a PR. In fact, a port is simply a special case of the bass reflex system.

Dave


Its the suspension and mass of a passive radiator that lags compared to air, and gives that delay like feeling to bass, not the resonant energy it has to pass. On the other hand a PR has normally much bigger surface than ports and is more opaque to transmitting enclosure resonances. Listen to slow big orchestral music and a PR wins. Listen to Electro, and a port wins. Less practical for bass reach, single resonance closed box, or even less practical non resonant OB, are faster and cleaner than any additional resonance augmentation approach. Just for reference, bcs practical wins the day in normal size systems, with all things accounted. Hence the omnipresent port.
 
salas said:

Its the suspension and mass of a passive radiator that lags compared to air, and gives that delay like feeling to bass, not the resonant energy it has to pass. On the other hand a PR has normally much bigger surface than ports and is more opaque to transmitting enclosure resonances. Listen to slow big orchestral music and a PR wins. Listen to Electro, and a port wins. Less practical for bass reach, single resonance closed box, or even less practical non resonant OB, are faster and cleaner than any additional resonance augmentation approach. Just for reference, bcs practical wins the day in normal size systems, with all things accounted. Hence the omnipresent port.

No. Read Richard Small's papers (The "S" in T/S parameters). The port is nothing more than the special case of bass reflex. There is no difference other than the additional resistive losses of PR suspensions and the localized effect due to Fp. Tune a PR low enough and the effect of that is minimized. Ported systems are used more often because they are much cheaper and easier to produce.

In addition, PRs are not known for allowing internal resonances and undamped signals to pass, quite the contrary, ports are unquestionably more prone to not impeding the passage of energy within the box and of additional resonances of the port itself. PRs largely block signals that are not within the resonant passband peak area of the PR.

Ported systems are resonances created by the air mass of the port coupled with the box compliance whereas PR systems are resonances created by the mass of the PR coupled the box compliance. They are both examples of the same concept. They are a mass connected to the box air as compliance.

I have never heard a truly top-notch ported system whereas I've heard much better in well designed PR systems. It's the same as with crossovers, it's the implementation that is paramount. Ported systems usually can't be tuned low enough due to the non-practical port lengths required if the port diameter is maintained large enough to prevent compression at higher volumes.

Dave
 

Salas

diyAudio Chief Moderator
Paid Member
2002-10-08 11:31 am
Athens-Greece
salas said:



Its the suspension and mass of a passive radiator that lags compared to air, and gives that delay like feeling to bass, not the resonant energy it has to pass. On the other hand a PR has normally much bigger surface than ports and is more opaque to transmitting enclosure resonances. Listen to slow big orchestral music and a PR wins. Listen to Electro, and a port wins. Less practical for bass reach, single resonance closed box, or even less practical non resonant OB, are faster and cleaner than any additional resonance augmentation approach. Just for reference, bcs practical wins the day in normal size systems, with all things accounted. Hence the omnipresent port.


dlr said:


No. Read Richard Small's papers (The "S" in T/S parameters). The port is nothing more than the special case of bass reflex. There is no difference other than the additional resistive losses of PR suspensions and the localized effect due to Fp. Tune a PR low enough and the effect of that is minimized. Ported systems are used more often because they are much cheaper and easier to produce.

In addition, PRs are not known for allowing internal resonances and undamped signals to pass, quite the contrary, ports are unquestionably more prone to not impeding the passage of energy within the box and of additional resonances of the port itself. PRs largely block signals that are not within the resonant passband peak area of the PR.

Ported systems are resonances created by the air mass of the port coupled with the box compliance whereas PR systems are resonances created by the mass of the PR coupled the box compliance. They are both examples of the same concept. They are a mass connected to the box air as compliance.

I have never heard a truly top-notch ported system whereas I've heard much better in well designed PR systems. It's the same as with crossovers, it's the implementation that is paramount. Ported systems usually can't be tuned low enough due to the non-practical port lengths required if the port diameter is maintained large enough to prevent compression at higher volumes.

Dave

Maybe I did not phrase well in English. I am sorry if I did that and created confusion, I am not a native speaker. But I basically see many points in your answer that are exactly in line with what I originally wanted to express.

Paragraph 1: I tried to say that the PR and BR systems don't differ in principle, but secondary things as elastic suspension and much bigger mass inertia in the PR guise, form a distinct sonic lag. Repeatable to my perception at least.

Paragraph 2: I used the word 'opaque' as a parallelism from the optic world to express the superiority of PR for degree of blocking internal box resonances to communicate to the outside space. No argument with what you say. Bad English again from a Greek guy as I am.

Paragraph 3: I never meant to say that they differ in concept, I only say that they differ in mass, inertia, and motional lag. Same thing as in 1.

Paragraph 4: I have heard excellent stuff from big pro sector top notch BR stacks, and mega buck residential behemoths such as Wilson Maxx and Avalon Isis.

Regards.
 
salas said:

Maybe I did not phrase well in English. I am sorry if I did that and created confusion, I am not a native speaker. But I basically see many points in your answer that are exactly in line with what I originally wanted to express.

Paragraph 1: I tried to say that the PR and BR systems don't differ in principle, but secondary things as elastic suspension and much bigger mass inertia in the PR guise, form a distinct sonic lag. Repeatable to my perception at least.

Paragraph 2: I used the word 'opaque' as a parallelism from the optic world to express the superiority of PR for degree of blocking internal box resonances to communicate to the outside space. No argument with what you say. Bad English again from a Greek guy as I am.

Paragraph 3: I never meant to say that they differ in concept, I only say that they differ in mass, inertia, and motional lag. Same thing as in 1.

Paragraph 4: I have heard excellent stuff from big pro sector top notch BR stacks, and mega buck residential behemoths such as Wilson Maxx and Avalon Isis.

Regards.

It was a bit my mis-reading of your post, looks like we mostly agree. However, I would take issue with just one aspect and that is the PR and mass. If the tuning is nearly the same, then the PR mass is simply the mass required to achieve that tuning. It doesn't make for any more "lag" in response. The key is simply in selecting a PR with the proper parameters for the tuning. It's quite possible to have a port and PR with nearly identical tuning so the mass considered alone is really not indicative of the result. The two systems will likely sound different in any case.

Part of the problem is that commercial systems too often have tunings meant more for sales than for the best sound, so I tend to see them as mis-tuned systems. Ported commercial systems usually are worse in this respect. But that's just my opinion.

Regards,

dlr
 

Salas

diyAudio Chief Moderator
Paid Member
2002-10-08 11:31 am
Athens-Greece
Very logical, your thoughts. Thanks.
I would still be looking into the much more than air's mass inertia (needed for tuning) and elastic curve of a PR diaphragm's suspension, with more suspicion towards to why there is an ultimate sonic signature mainly in rhythmic coherence, not necessarily bad or not able to be incorporated in the big scheme of things tonal.
Another point is that a PR is normally seen in better than average speakers that try to go beyond normal compromises. So they will be better class overall. Also a PR will be having more area than averagely sized ports and that is a dynamic boost without the breathing noise and internal resonance transmission of a BR. Hope I expressed difficult tech thoughts in English better this time, if not, I will say one thing I know for sure...Merry Christmas!
 

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salas said:
Very logical, your thoughts. Thanks.
I would still be looking into the much more than air's mass inertia (needed for tuning) and elastic curve of a PR diaphragm's suspension, with more suspicion towards to why there is an ultimate sonic signature mainly in rhythmic coherence, not necessarily bad or not able to be incorporated in the big scheme of things tonal.
Another point is that a PR is normally seen in better than average speakers that try to go beyond normal compromises. So they will be better class overall. Also a PR will be having more area than averagely sized ports and that is a dynamic boost without the breathing noise and internal resonance transmission of a BR. Hope I expressed difficult tech thoughts in English better this time, if not, I will say one thing I know for sure...Merry Christmas!

You're doing fine, I need to be sure I read carefully as well.

The elastic properties of the PR should have no influence up to the point that the PR's max displacement begins to enter into it. Keep in mind that a PR is driven by the air mass uniformly over its entire surface, so there should be no differential pressure anywhere when it's within its displacement limits. There will be some small amount near the spider attachment area, but that should be minimal for most of the displacement range.

That said, I do prefer to distribute weight on a PR rather than add it all as a mass on a post at the center as many PRs provide.

Ports are more limited due to area as you say. That's probably why I have never liked them because the length required for large port areas is impractical.

Regards and Merry Christmas,

Dave