homemade

Here's a terrible picture of it. (Sony TR730 camcorder in very low light). You can see that it doesn't have the sides extending to the walls and top plate that would seal it to the corner and no tailboard. I really don't believe this effects the low end at all. This is from a later Speakerlab plans that actually houses the 6.5 inch midrange and tweeter in an enclosure that is built into the front of the bass bin instead of the top. You can see that I put the midrange and tweeter in a separate box on top so I could rotate them like I wanted. They claimed a freq. response of 32-20khz +-3db in their add! I really believe that the midrange Audax driver gives the speaker a very nice sound without any kind of horn resonances in the midrange. I haven't listed to a Klipchhorn so I don't know for sure but I really love the midrange of this combo.

My Speakerlab plans are a bit different than the earlier plans in that the top board doesn't go all the way into the corner and there is no tailboard as such. There is actually an 8inch gap between the back of the top board and the corner. I have experimented with a top board to seal the walls but I wasn't able to measure any difference in low end response. I believe that sealing the khorn to the corner only affects the upper bass range. I was playing an organ recording that all of a sudden has a -6db 21hz pedal tone (loudest low freq. signal any of my recordings have beside maybe some dvd movies I've rented) and if eqing the low end too much and turning up the bass knob resulted in a reading of 110db at my couch with that note but noticable distortion (probably from the woofer bottoming out). The low note will shake the window in the other room. The khorn will easily take the low note signal if volume is kept below 3\8 and low end eq. is kept below 12db for a db level of around 95 or so. The funny thing about this low note organ is that the bass is out of phase between left and right and one subwoofer won't began to produce any tone. I'd like to have someone post this note from an mp3 I can make and see what their systems can do with it. Anyone interested? I could email you the small mp3 file.

I went ahead and modded the other speaker and re-ran a freq. response test with the meter in another location and couldn't really dicern any difference from the before and after mods. I did run the woofer without an inductor and it made the sound muddy and too tubby from too much midbass output. I'm actually satisfied with the midrange crossover point and output. The curve starts out at 60hz at 0db and increases to a high of +8db at 160hz and starts going back down to 0db at 400hz or so and than dips 2db slightly and back up to 0db at 1,000hz. I use my eq. to decrease the upper midbass output aprox. 4db and increase the 40hz setting 6db. I'm running a 12db/octave high pass filter at the midrange and tweeter. Now sure of the values without removing my crossover.

Well, I couldn't wait and ripped the speaker apart and made the mods. I posted a freq. response first to verify any differences. This is for an uncorrected Radio Shack meter reading in the middle of the room which is far from ideal. (11.5x13x9ft with a door in the back and the left wall has an opening 5ft wide. 25hz is off the scale, 31--10,40--6,50--6,63-0,80-+4,100+8,125-+3,160-+8,200-+4,1000-0. I removed the motor board, opened up the opening from 3x13-6x13, took out the fiberglass fill, re-ran the tests and the lows actually went down very slightly and the 100hz setting wasn't at +8 anymore but more like +6. Put the fiberglass back in and re-ran tests and basically the same thing. I know some of the bass rolloff below 60 is because of the middle of the room and towards the back where I sit it picks up in the lower octave. Was this mod worth it? If it reduces the 125hz peak a little-probably so. I'll probably modify the other speaker to have a matched pair. I still like the sound better if I crank in 12db of gain in the 20-40hz range though. What I probably need is the Adire Tempest with 250watt amp in a sealed 3.5 cu. ft box but that'll cost me around $250 and somewhere to put it.(I already have a box). Would anymore speculate whether the Tempest can put out decent enough volume at 20-25hz to keep up with the khorn in at least movie sound?

I thought the smaller slot was suppose to raise the response around 400 hz or so? I think I will go ahead and cut out the panel to 6x13 and mount the woofer directly to the housing and forget the mounting board unless I decide to go back to it I can just install it and be done. I understand the later khorns don't even use a motor board? How much greater efficiency and low end? I don't want to add much because I'm midrange limited by my 6.5inch Audax speaker. If I could achieve less response in the 1-200 range and more under 50 that would be great but I don't want to be adding any in the upper bass.

D-Man, what can I expect if I cut my slot to 6x13inches? I'm thinking about doing the mod and even doing away with the motor board. Will it change only the upper limits of the woofer or the low end also? I tried to do some research and didn't come to any conclusions about the low end but some did claim to have better low end by doing away with the motor board. I can't imagine this little change would make that great of difference. I wonder when McGee Radio went out of business? I live near Wichita and not K.C. so I've never been in the store, only had their catalogs from years ago.

I built some khorns from speakerlab plans about 15 yrs ago and while visiting this forum it got me thinking about modifying them. I used an Eminence 15inch speaker from McGee Radio out of K.C. I used a 6.5 inch Audix HRM17 midrange driver that has 99.6 db efficiency and the EV T35 tweeter. I was pretty satisified with the sound if I used an eq. to reduce the midbass and increase the lower bass. For the crossover I wasn't using anything on the woofer. I ran it in this mode for the past 14 yrs or so. I read some posts about adding some dampning material to the back chamber and doing away with the coil. Well, I added some fiberglass sheets to the back chamber and didn't notice much difference. I than proceeded to add the coil back to the woofer. I located some 6.2mh coils and added them. I noticed less midbass and more balanced sound. Did some quick measuring and found the coil cut the output to woofer aprox. 1.5 db and lowered the output significantly between 150-400hz. I'm probably running too low high of mh coil but it does sound more balanced. The next step was to email Eminence and find out what I was actually running for woofer compared to the K33. Here's a quote from the email: "The 5415's that you have were custom manufactured for McGee. We have a couple of drivers that are close. Our Delta 15 is a good parameter match but it has a much shorter coil which will give you less excursion. Our Delta 15LF is a good match as far as soft parts go but the parameters don't match as well. Below are the T/S params for your McGee's and the Klipsch K-33. The McGee's should be good for 300-350 watts and the K-33's 200-250 watts. 01-SPEC 15467 04-DATE 06/06/94 02-PART # EM5415HI8 03-MODEL # 1525F5637 05-RE OHMS 5.37 13-FS HZ 35.38 06-LE MH 1.42 14-MMS GMS 80.19 07-QM 7.91 15-CMS mm/N .2523 08-QE .480 16-RMS NS/M 2.2545 09-QT .460 17-VAS LTRS 259.89 10-XMAX MM 7.30 18-SD SCM 856.34 11-BL TM 14.08 19-EBP 73.3 12-EFF % 2.30 20-SPL dB 95.6 01-SPEC 15162A 04-DATE 11/30/92 02-PART # K-33 03-MODEL # 1520F5637 05-RE OHMS 3.39 13-FS HZ 34.46 06-LE MH .96 14-MMS GMS 78.59 07-QM 7.39 15-CMS mm/N .2714 08-QE .410 16-RMS NS/M 2.3037 09-QT .390 17-VAS LTRS 301.66 10-XMAX MM 8.20 18-SD SCM 889.59 11-BL TM 11.88 19-EBP 84.4 12-EFF % 2.91 20-SPL dB 96.6 " I noticed he said that my woofer was rated for 300-350 watts and the Klipsch speaker 200-250. Interesting. I only lost 1 db efficiency (I'm running the 8ohm speaker too) and 1mm less xmax. Does anyone know what the effect the differenct QT and VAS would have on my speaker from the K33? I than proceeded to measure the effeciency of my speaker. I ran white noise from my amp and measure 2.73volts at the speaker and my Radio Shack meter read 103db after I backed off the tweeter adj. because it made the meter peak past 109 db. I'm guessing my 6.5 inch midrange is over 100db efficient and possibly close to 103 which is what the meter read with the woofer and midrange going. I only thought my speakers were in the 100db effecient range. Maybe my voltmeter is off! Maybe I'm getting to the point of removing the 15 band eq. in my system! Now, I'm thinking of buying an Adire Tempest 15inch subwoofer to add some needed lower octave power?

DAX616, the flutter you're hearing might be an air leak at the joints of the box. I had to add some more screws to my woofer cover to control the vibration and consequent air leaks on my homemade khorns. Remember, the bass rolls off fast below 40hz or so and that's why your low bass isn't as powerful as it could be. A little help from an eq. (here we go again) will balance things out wonderfully. How loud do you listen to your music? What's the freq. and power level of the bass in the music? Can you run a freq. analysis in a program to find out what kind of energy there is down low? According to my khorn literature from the mid 90's or earlier, the response is down 10db at 30hz compared to 40hz and 40hz is down 4db from 200hz. What did you think of the impact of the bass at high levels?

I built some homemade 901's in the early 80's like Bose's early models. (wood cabinet). They were ok sound but really needed a 200watt/channel amp. Bose actually marketet a setup that included 4 901's with a monster amp. Now, the speaker without eq. was actually efficient in the midrange (I wouldn't doubt they were around 95-98 db efficient in the range from 200-8000 cycles but the lower bass and highest treble needed all the boost a 10 band eq. could muster. I was never really satisfied with the bass handling capacity. Sold them to a friend and buit a satelite/subwoofer sytem (12inch subwoofer) and the bass was inadequate with them also. I will admit though, that when used as a pa speaker in the 801 series they sounded good enough for a small venue. At least they had decent bass response compared to other pa speakers at the time. Just not enough bass for my liking in the home. I can't comment on the newer plastic cased 901's as I've never listened to them for any length of time although our dorm floor had a party with them and I didn't think they were too bad but also lacked low bass but upper bass was decent.

I have mentioned it many times and no one has answered it: How many recordings put out full volume at 35 hz? Perhaps the 10db increase bothers the ones using smallish amps. I don't think I've ever heard my 60 watts/channel amp ever go into distortion at higher levels (perhaps my ears give up before the distortion sets in). DJK mentions a Q2 (6db increase at 31hz) eq to level out the bass response of his ported enclosures but no one give him any grief over the increased amp level required. Here we have John Warren mentioning the increased resistance on the speaker because of the horn loading and increasing bass increases the stresses further. I thought that horn loading had no "play" in the lower frequencies below cutoff? Now it does? Does it or doesn't it? I sure thought it made some difference in the La Scala bass bin thread and I got blasted by suggesting it did. I am through with trying to suggest anything in these threads anymore. I will continue to peak in from time to time because I enjoy the mods and what makes these speakers tick but it's getting too full of people who have very strong opinions and nobody apparently appreciates any of my comments. I have tried and related my experiences and people blast me for suggesting that perhaps one can eq. to gain bass and I can't believe the neg. response to that yet other people suggest it without any neg. response whatsoever. I'm going now to blow my woofers with my 60 watt amp!

DJK; call me at 620-983-2075 and we can talk (calmly). I don't know if you don't understand what I'm saying or are you just that way?

DJK; your attitude is again getting the best of you. In direct radiator mode the khorn woofer has a 96 db efficiency and in horn loaded mode aprox. 104db. I'm saying that there is an 8db increase by horn loading, oh forget it-you're attitude prevents you from understanding me. Michael, I don't think I could stand running my khorns at 50 watts and all of a sudden have a full volume sound at 35hz that would require 500 watts amp power. I don't think I have ever run my khorns into distortion from overpowering the woofer. You could very, very, easily run 12db boost without any problem unless you like your music ear splitting level (above 115decibals).

Your khorns will take any kind of boost in the low frequencies as you can stand! I've had my homebuilt ones for yrs with a 10 now 15 band eq. with the bottom octave boosted 12db and the 125 range reduced aprox. 4db to tame the upper bass. All you're doing with the lower octave is raising the level to the higher efficiency horn loaded level. You're not demanding anymore from the woofer as you would if it were in a direct radiator enclosure. Now, I wouldn't suggest running 200 watts through it for hours that way but in a home in real life you couldn't stand the output before damage would be done. A 7 band eq. wouldn't give you the bottom octave control though that would needed for a flat response (maybe you like some 60hz kick though). I purchased a 15 band eq. on ebay for $28 plus shipping. It's a pro model with xlr and 1/4inch inputs plus rca inputs. The only problem I noted was last night when playing a dts encoded dvd I had to turn the volume close to 1/2 volume to get realistic levels and a little hiss was noted but not bothersome. If playing music at this level it would aproach 115 db at the listening postition and that's too much.

Thanks Marvel for the specs on the K33E. I'm personally running some Eminence speakers in my homebuilt khorns that I purchased 15 yrs ago from McGee Radio out of K.C. The only specs listed on them in the catalog was a 2inch vc, apparently 32hz fo and 92 db efficiency. They have a 54 oz magnet. They do appear to have a little less efficiency than the K33E but I'm running the 8ohm version instead of 4 ohm and the efficiency matches up perfectly with my Audix6.5 inch midrange driver rated at 99.6db efficiency. They listed an enclosure of 2.75 cu ft and a port of 4 inches dia. and 5inches long. I haven't calculated out the woofer specs from there but probably too many variables to get an acurate idea of specs and who knows if they actually went by any thiele measurements when they said what box size to use. The 4ohm version is said to have 93 db efficiency. Does Eminence even make any non musical type speakers anymore? They said in the add for the speaker that it was a good khorn replacement speaker. Perhaps a little low in effieciency though unless one used the 4ohm version.

DJK: Where's the moderator on this forum? Calling people morons and failing 8th grade science is not needed. Where are your manors? I will check the links you provided and check them out. Look, all I said was that with all the work going into the boxes you're not going to get flat response without an eq. of some sorts and Marvel explained it pretty well. I still don't understand your opinion of a 10band eq. being a POS. Where's your data to back this up? My reference to the throat as messing things up for the math involved was not the same as saying a restrictor in the front of the woofer will make it a horn-djk. I know that my khorn's back enclosure is very small and making a cabinet the same size and putting the 15inch woofer in it will sound terrible-way too high of Q and resonant freq.-I haven't figured out what it is because I don't know what the specs on my speaker (or the K33e) are. On my literature of the La Scala it shows a 5db dip from 40hz to 35hz and than back up again at 30hz. Perhaps this is the dip at 40hz that Forde is experiencing. Look, if we're using an eq. anyway why not make it a multibanded one and tame the upper bass?

Quote: Gee, you're so smart, why ain't you rich? Me: What an attitude!!!!! Quote: And he doesn't get it even after I explained filter 'Q' in a previous post.Some people don't get it no matter how many times you show it to them. If you get it it seems simple, if not Me: You don't get it!!! I'm saying you can't get flat response by running a ported enclosure for the bottome octave and a horn for the rest of the spectrum! You're talking a running a Q factor that would boost the bass. I would have to go back and see if you're talking about using an eq. with a high Q factor or tuning the box to a high Q factor. If you're tuning the box to achieve a high Q factor-good luck with having smooth bass. Maybe you can. Talking about the 40hz response: Quote: Common sense: phase cancellations can be infinite, peaks are finite. Me: Where is the infinite phase cancellation? Just because a modified speaker has 0db change at a certain freq. doesn't mean it's automatically a phase cancellation problem. Wasn't one of the response measurements with a larger sealed box without ports? Quote: The port is tuned two octaves below Fc of the horn, the horn has no effect to speak of Me: Are you saying the constricted throat has absolutely no bearing on how the woofer behaves at lower frequencies? Do you have data to back this up? I still don't understand your reference to white and rotary knobs and POS. Maybe your attitude is POS!

DJK, What do you mean a 10band eq. is a pos compared to the ev eq? Now, all of your Q specs can be thrown out the windowbecause we really don't know how the woofer will react in a horn loaded enclosure with a constricted throat size, etc. I think we are on experimental terms here and not so mathimatical explanations that you are giving us. I don't see how this is a simple (not really simple) ported box. To achieve flat response an eq. of some sorts is going to be needed regardless of whether it's sealed, ported, enlarged, whatever. Can we gain some bass by enlarging and porting-sure. How did you know the 40hz response is due to phase cancellation? I'd like to see more actual freq. response measurements from the modified vs unmodified.

DJK, Looking at the freq. response posted I see a 10db disparity between 125hz and 31 hz and more at 40hz. How much eq. does the EV eq. give anyway? You mention 2db at 50hz but what about 31 hz? I would venture to say that the dip at 40hz isn't a room "suckout" but the natural response of the speaker and the gain at 31hz is the room interactions. Look at the stock specs-it's about what the response of the LS is that Klipsch has in their literature. Yes, one is gaining some lower octave boost in the 5db range or so but it's not enough to keep up with the horn loaded upper bass. I still say a 10-15 band eq. is better than the EV eq. in that the upper bass can be tamed. Using a 15 band eq. is a lot simpler than modifing the speaker? Freq. response would be on the order of the khorn with perhaps 5db less output in the 40hz-60 range and the same response in the 30 hz range.

I can understand the reasoning behind getting an EV eq for extended bass response but I fail to see where the -3db freq. of 31hz or lower will really be -3db. Yes, in a direct radiator app. that would be the f3 freq. but we are dealing with a horn loaded upper bass that is going to add 10db to the efficiency of that region. Am I not wrong in this assessment? Doesn't the Altec A7 have this same problem? You are still going to have to boost the lower octave via an eq. and not just use the eq. an EV Sentry speaker has. My biggest complaint about the khorn and I assume the LS (haven't really listened to one recently in any home) is that the upper bass is way over accenuated compared to the lower octaves and the octaves above 300 hz or so. This leads to a resonant quality that is not natural. That's why I was talking about the tympani being over actunated. I did recently record a high school band and noticed the overemphazed tympani drum even when reducing the 100-200hz range about 4 db. Yes, a tympani drum in my room would shake the couch but sitting back about 50 ft from the drum should tame things somewhat. How do you guys who are very picky about your sound deal with the overboosted upper bass without an eq.? Perhaps this phenomina isn't as apparent with symphony music as it is with some voice recordings and even pop music with overemphasized male voices.

In my previous house I had to use one khorn off of a corner (about 10ft from the corner) and I didn't notice any loss of bass (I even measured it). The loss of bass at the extreme end was the same (35hz down perhaps 10 db or so). I don't see how you're getting -3db at 35 hz without some eq.ing. So your 35hz is -3db-what's the output between 100-200hz? I don't believe there is any magic in false corners and tightly sealing the boxes to the corners. The response is basically fixed from the throat area.

With 12 db of boost at 30hz one would probably never see the amp overpowering the woofer at this frequency. I've run mine for 15yrs this way without the amp ever going into overload and experiencing the woofer bottoming out. I used to use a 200watt/channel amp and now run a 60watt/channel surround reciever. Most of the energy of music is probably in the 100hz range. Does anyone know of a recording that pumps out max. volume at 30hz? Also someone was saying that the mod made them as efficient at 35hz as at 100hz. This can't be without using the port as a passband type of hyper one note bass. The lower octave in this mod will only be as efficient as the K33 woofer used as a direct radiator. The specs shown on one example of this mod was taking some room effects into account. Would I do this mod. I sure would if I had some homemade LS's. The gain of 5db or so at 30hz is probably worth it but one will still need to boost the lower octave via an eq. to get a flat low end response and to tame the upper bass range unless one likes the tympany drum to vibrate the couch.

I found the writing about the different f3's, etc. very interesting. I always loved the look of the LS's but remember them sounding very "thin" in the showroom. Now, getting the f3 down into the low 30's or even high 20's would be wonderful but there is one thing that I believe we're forgetting: this f3 and the proceeding octave will still be aprox. 10db lower in efficiency (due to the efficient horn loading of the bass from 70hz on up). If one compares the khorn to the LS freq. response they are very similiar except for the lower octave of bass. I really wonder if an LS can have decent bass by using a simple 10-15 band eq. and jack up the lower octaves sufficiently and be done with it. I know that people here on the forum object to using an eq. but even with the mods you'll still be down 10db at 30-45 hz and that will still sound "thin".

My homemade khorns allow right at 28inches from the corner to point D. I bet he khorns will be another 6inches into the screen. I used some speakerlab plans from the mid 80's and mine don't have a tight fitting top board or from C to D is only 24 inches and height of bass bin is 40 inches.

I like my panasonic F87. It has some kind of digital output but also a built in dts decoder and dolby prologic II decoder. The prologic decoder sounds so much better than my Yamaha reciver's decoder (I get lots of distortion from the Yamaha on bass notes such as an organ). I think I paid about $89 on ebay. The sound output via analog outputs is reported to be decent also. No need for an outboard converter.

A 10db increase from 1 watt is 10 watts, not 100 watts but I doubt that a 30hz signal is ever as loud as the 120hz band in real music. My old 12inch subwoofer could only handle 25 watts at 25hz or so. Remember, we're talking a big 15 inch speaker with 54oz magnet and tight suspension in a very small back chamber. I ran mine with the side access panel out and I saw very little movement for the most part. I'm not sure what's happening when applying 100 watts at 30hz though but if the access panel doesn't vibrate excessively I doubt the cone is moving an excessive amt.